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5,500 | [Amiodarone-induced liver dysfunctions]. | Amiodarone, a diiodinated benzofuran derivative, is widely used for treating ventricular and supraventricular tachyarrhythmias. Amiodarone is highly lipophilic and accumulation in the liver can be 500 times higher than serum amiodarone levels. Due to a long half-life and the lipophilic properties, the stored drug is capable of damaging the liver long after the drug has been stopped. Serious liver damage can lead to acute liver failure, cirrhosis and the need for liver transplantation. In this article we describe amiodarone-induced liver dysfunction and the diagnostic and therapeutic challenges in patients on amiodarone. |
5,501 | Ventricular fibrillation caused by electrocoagulation in monopolar mode during laparoscopic subphrenic mass resection. | Monopolar is usually a safe and effective electrosurgical unit used in laparoscopic general surgery. However, it can cause adverse outcomes and even cardiac arrest. We present a video of laparoscopic subphrenic mass resection using monopolar coagulation during which ventricular fibrillation occurred and from which the patient was successfully resuscitated.</AbstractText>Our patient was a 39-year-old man who was admitted to our institution for treatment of a liver mass. The mass was located in the left subphrenic region and was 3.31 cm × 2.7 cm according to B ultrasound. He had had a spleen resection after a car accident 14 years before. He was otherwise healthy and a physical examination was negative. He was scheduled for "laparoscopic exploration, mass resection." General anesthesia was induced and the operation began. While dissecting the mass from the diaphragm there was some bleeding; monopolar electrocoagulation with 68 W was performed upon which ventricular fibrillation occurred. The operation was stopped and closed-chest compression began immediately. Defibrillation (200-J shock) was performed in 1 min and rhythm returned to sinus.</AbstractText>The operation was resumed carefully and uneventfully. The patient was sent to the postoperative acute care unit and was extubated 10 min after operation. The patient recovered uneventfully without any signs of permanent cardiac injury and was discharged on postoperative day 3. The final pathology was accessory spleen.</AbstractText>We present a video of a patient who experienced ventricular fibrillation during laparoscopic surgery which was successfully defibrillated leaving no permanent cardiac injury. We assume the reason for the ventricular fibrillation was the low-frequency leakage current from electrocoagulation which may be conducted by Swan-Ganz catheter to the heart. It is important that we be familiar with the character of electrosurgical unit when performing laparoscopic surgery. We should be careful when using an electrosurgical unit near the cardiac region, especially when the patient has an indwelling catheter. We recommend performing hemostasis in bipolar mode or use an ultrasonic scalpel if bleeding is close to the heart. Also, an easily available defibrillator should be ready for use.</AbstractText> |
5,502 | The correlation between left ventricular failure and right ventricular systolic dysfunction occurring in thyrotoxicosis. | Heart failure rarely occurs in patients with thyrotoxicosis (6%), with half of the cases having left ventricular dysfunction (LVD). Although a few studies reported isolated right heart failure in thyrotoxicosis, there has been no evaluation of relationship between LVD and right ventricular dysfunction (RVD).</AbstractText>We enrolled 12 patients (mean age: 51+/-11 years, 9 females) diagnosed as having thyrotoxicosis with heart failure and LVD {left ventricular ejection fraction (LVEF) <40%}, and divided them into two groups {Group I with RVD defined as tricuspid annular plane excursion (TAPSE) less than 15 mm and Group II without RVD}. Clinical features, laboratory variables, and echocardiographic parameters were compared between two groups.</AbstractText>RVD was found in 6 (50%) patients. On admission, there were no significant differences between the two groups in clinical features, laboratory variables, or echocardiographic parameters including atrial fibrillation {6 vs. 5, not significant (NS)}, heart rate (149+/-38 vs. 148+/-32/min, NS), LVEF (36.7+/-9.5 vs. 35.1+/-6.3%, NS), or the tricuspid regurgitation peak pressure gradient (TRPPG, 30.9+/-2.0 vs. 36.3+/-9.3 mmHg, NS). After antithyroid treatment, all achieved an euthyroid state and both ventricular functions were recovered. All data, including the recovery time of LVEF and the change of heart rate between two groups, displayed no significant differences.</AbstractText>In half of patients, RVD was combined with thyrotoxicosis-associated LVD. There were no differences in clinical factors or hemodynamic parameters between patients with and without RVD. This suggests that RVD is not secondary to thyrotoxicosis-associated LVD.</AbstractText> |
5,503 | A randomized invasive cardiac electrophysiology study of the combined ion channel blocker AZD1305 in patients after catheter ablation of atrial flutter. | This study assessed the cardiac electrophysiological and hemodynamic effects of an intravenous infusion of the combined ion channel blocker AZD1305.</AbstractText>After successful ablation of atrial flutter, patients were randomized to receive placebo (n = 12) or AZD1305 (n = 38) in 4 ascending dose groups. Electrophysiological and hemodynamic measurements were performed before and commencing 20 minutes after start of infusion.</AbstractText>Left atrial effective refractory period increased dose and the primary outcome measure increased dose and plasma concentration dependently, with a mean increase of 55 milliseconds in dose group 3. There was a corresponding increase in right atrial effective refractory period of 84 milliseconds. The right ventricular effective refractory period and the paced QT interval also increased dose and concentration dependently, by 59 and 70 milliseconds, respectively, in dose group 3. There were indications of moderate increases of atrial, atrioventricular nodal, and ventricular conduction times. No consistent changes in intracardiac pressures were observed, but there was a small transient decrease in systolic blood pressure. Adverse events were consistent with the study population and procedure, and there were no signs of proarrhythmia despite marked delay in ventricular repolarization in some individuals.</AbstractText>AZD1305 shows electrophysiological characteristics indicative of potential antiarrhythmic efficacy in atrial fibrillation.</AbstractText> |
5,504 | The P-selectin gene polymorphism Val168Met: a novel risk marker for the occurrence of primary ventricular fibrillation during acute myocardial infarction. | The P-Selectin Gene Polymorphism Val168Met.</AbstractText>Ventricular fibrillation (VF) in the setting of acute myocardial infarction (AMI) is the leading cause of sudden cardiac death (SCD). Family history of SCD is described as risk factor for primary VF during acute AMI. Genetic factors may be associated with primary VF. We examined polymorphisms in genes related to the activation and adhesion of blood platelets in patients with and without VF in the setting of AMI and among healthy controls.</AbstractText>Two hundred and forty patients with a history of AMI and 475 healthy controls were studied. Seventy-three patients (30%) had primary VF during AMI. By using PCR techniques with sequence-specific primers (PCR-SSP), we genotyped 5 single nucleotide polymorphisms (SNPs) in P-selectin (SELP) (V168M, S290N, N592D, V599L, T715P), 2 SNPs (M62I, S273F) in P-selectin glycoprotein ligand-1 (SELPLG), 5 SNPs in CD40LG (-3459A>G, -122A>C, -123A>C, 148T>C, intr4-13T>C), the H558R SNP in SCN5A, and rs2106261 in ZFHX3. In addition, length polymorphisms in SELPLG (36bp-tandem repeat) and CD40LG (CA-repeat) were genotyped by PCR methods. Results were evaluated by 2-sided t-tests, chi-square tests, and logistic regression analysis.</AbstractText>None of the gene polymorphisms showed significant differences between AMI patients and healthy controls. Among patients with a history of VF, however, the SELP 168M variant showed a significantly higher prevalence (14/73 patients; 19.2%) as compared with patients without VF (13/167 patients; 7.8%; P < 0.01). This association remained significant in a logistic regression analysis after adjustment for age and gender (P = 0.013; odds ratio 2.8; 95% confidence interval 1.2-6.3).</AbstractText>This is the first description of an association of the SELP gene variant 168M with primary VF during acute MI. This variant may be a candidate polymorphism for evaluating the susceptibility for VF in the setting of acute MI.</AbstractText>© 2010 Wiley Periodicals, Inc.</CopyrightInformation> |
5,505 | Specific residues of the cytoplasmic domains of cardiac inward rectifier potassium channels are effective antifibrillatory targets. | Atrial and ventricular tachyarrhythmias can be perpetuated by up-regulation of inward rectifier potassium channels. Thus, it may be beneficial to block inward rectifier channels under conditions in which their function becomes arrhythmogenic (e.g., inherited gain-of-function mutation channelopathies, ischemia, and chronic and vagally mediated atrial fibrillation). We hypothesize that the antimalarial quinoline chloroquine exerts potent antiarrhythmic effects by interacting with the cytoplasmic domains of Kir2.1 (I(K1)), Kir3.1 (I(KACh)), or Kir6.2 (I(KATP)) and reducing inward rectifier potassium currents. In isolated hearts of three different mammalian species, intracoronary chloroquine perfusion reduced fibrillatory frequency (atrial or ventricular), and effectively terminated the arrhythmia with resumption of sinus rhythm. In patch-clamp experiments chloroquine blocked I(K1), I(KACh), and I(KATP). Comparative molecular modeling and ligand docking of chloroquine in the intracellular domains of Kir2.1, Kir3.1, and Kir6.2 suggested that chloroquine blocks or reduces potassium flow by interacting with negatively charged amino acids facing the ion permeation vestibule of the channel in question. These results open a novel path toward discovering antiarrhythmic pharmacophores that target specific residues of the cytoplasmic domain of inward rectifier potassium channels. |
5,506 | Mechanisms of hypokalemia-induced ventricular arrhythmogenicity. | Hypokalemia is a common biochemical finding in cardiac patients and may represent a side effect of diuretic therapy or result from endogenous activation of renin-angiotensin system and high adrenergic tone. Hypokalemia is independent risk factor contributing to reduced survival of cardiac patients and increased incidence of arrhythmic death. Animal studies demonstrate that hypokalemia-induced arrhythmogenicity is attributed to prolonged ventricular repolarization, slowed conduction, and abnormal pacemaker activity. The prolongation of ventricular repolarization in hypokalemic setting is caused by inhibition of outward potassium currents and often associated with increased propensity for early afterdepolarizations. Slowed conduction is attributed to membrane hyperpolarization and increased excitation threshold. Abnormal pacemaker activity is attributed to increased slope of diastolic depolarization in Purkinje fibers, as well as delayed afterdepolarizations caused by Ca2+ overload secondary to inhibition of Na+--K+ pump and stimulation of the reverse mode of the Na+--Ca2+ exchange. Hypokalemia effect on repolarization is not uniform at distinct ventricular sites thereby contributing to amplified spatial repolarization gradients which promote unidirectional conduction block. In hypokalemic heart preparations, the prolongation of action potential may be associated with shortening of effective refractory period, thus increasing the propensity for ventricular re-excitation over late phase of repolarization. Shortened refractoriness and slowed conduction contribute to reduced excitation wavelength thereby facilitating re-entry. The interplay of triggering factors (early and delayed afterdepolarizations, oscillatory prepotentials in Purkinje fibers) and a favorable electrophysiological substrate (unidirectional conduction block, reduced excitation wavelength, increased critical interval for ventricular re-excitation) may account for the mechanism of life-threatening tachyarrhythmias in hypokalemic patients. |
5,507 | Single-beat determination of right ventricular function in patients with atrial fibrillation. | In atrial fibrillation (AF), left ventricular (LV) systolic function positively correlates with the ratio of the preceding to prepreceding RR intervals (RRp/RRpp) and single-beat determination of LV function at a beat with equal RRp and RRpp closely estimates the average value over all cardiac cycles. The study was designed to evaluate the feasibility of single-beat determination that was based on the ratio of RRp/RRpp to accurately assess RV function in AF.</AbstractText>In 60 patients with AF, RV fractional area change (RVFAC), RRp and RRpp were measured during 20 beats for each patient. The relationship between RVFAC and RRp/RRpp was evaluated by linear regression analysis. The measured values of RVFAC at the beats with equal RRp and RRpp were compared with the average values over 20 beats. The influence of RRp cycle lengths on the values of RVFAC at the beats with equal RRp and RRpp was examined from the plot of normalized value against RR intervals.</AbstractText>There were a positive linear relationship between RVFAC and RRp/RRpp in all patients (P < 0.001 in all). The RVFAC measured by single-beat method and cycle lengths < 500 ms were usually far below the average values. After excluding beats with cycle lengths < 500 ms, RVFAC determined by single-beat method was very close to the average values (y = 0.96x + 1.91%, r = 0.961; P < 0.001; bias 0.26%).</AbstractText>RV FAC correlates positively with RRp/RRpp and single-beat determination of RV function is feasible and accurate in patients with chronic AF.</AbstractText>© 2010, Wiley Periodicals, Inc.</CopyrightInformation> |
5,508 | Survival in out-of-hospital cardiac arrest before and after use of advanced postresuscitation care: a survey focusing on incidence, patient characteristics, survival, and estimated cerebral function after postresuscitation care. | Knowledge of the epidemiology of postresuscitation care is insufficient. We describe the epidemiology of postresuscitation care in a community from a 26-year perspective, focusing on incidence, patient characteristics, survival, and estimated cerebral function in relation to intensified postresuscitation care and initial arrhythmia.</AbstractText>The study included patients with out-of-hospital cardiac arrest (OHCA) who were brought alive to a hospital ward in Göteborg, Sweden, between 1980 and 2006. Two periods (1980-2002 and 2003-2006) were compared.</AbstractText>In all, 1603 patients were included. For age, sex, and history, no significant differences between the 2 periods were seen. There was a significant multiple increase in bystander cardiopulmonary resuscitation, the use of coronary angiography, coronary revascularization, and therapeutic hypothermia. The number of patients found in ventricular fibrillation (VF) decreased (P = .011). For all patients, 1-year survival did not change significantly (27% vs 32%; P = .14). Among patients found in VF, an increase in 1-year survival was found (37% vs 57%; P < .0001), whereas no significant change was seen in nonshockable rhythm (10% vs 7%; P = .38). Survivors to discharge displaying low cerebral function (ie, cerebral performance categories score >or=3) decreased from 28% to 6% (P = .0006) among all patients.</AbstractText>After the introduction of a more intensified postresuscitation care, there was no overall improvement in survival but signs of an improved cerebral function among survivors. There was a marked increase in survival among patients found in a shockable rhythm but not among those found in a nonshockable rhythm.</AbstractText>Copyright (c) 2010 Elsevier Inc. All rights reserved.</CopyrightInformation> |
5,509 | [ILCOR recommendation on signage of automated external defibrillators (AEDs)]. | Early defibrillation is a determinant of survival in both out-of-hospital and in-hospital cardiac arrests from ventricular fibrillation and pulseless ventricular tachycardia. The review summarizes importance of early defibrillation with automated external defibrillators (AED) and presents the International Liaison Committee on Resuscitation (ILCOR) recommendation for universal AED sign. The aim of the recommendation is to unify the AED signs worldwide and to spread the knowledge of this. The public in general, but healthcare professionals particularly, should be able to recognize AED location and use the device immediately in case of cardiac arrest. |
5,510 | [Gender differences in non-pharmacological treatment of chronic heart failure]. | Prior studies demonstrated sex-related differences in many aspects of chronic heart failure (HF), and in the appropriate use, individual response or complication rates with non-pharmacological treatment, too. There is seasonal variability in morbidity and mortality of HF with significant gender differences, partially due to respiratory diseases, which may be potentionally preventable by vaccination. Quitting smoking is associated with substantial decrease in morbidity and mortality in HF patients which is similar in magnitude to the effect of an appropriate beta-blocker use. Yet little emphasis has been placed on smoking cessation strategies in women with HF and should be adopted as vigorously as proven medical therapy. Complications of catheter ablation for atrial fibrillation were more frequent in females. Gender disparity exists in the use of implantable cardioverter-defibrillators and cardiac resynchronization therapy, although they are beneficial for both women and men. Smaller women have limited access to left ventricular assist device (LVAD) because these devices require a minimum body surface to fit properly. Women were more likely than men to develop severe right ventricular failure after implantation of LVAD. Lower cut-off level of peak oxygen consumption was suggested for women to determine optimal timing for heart transplantation. Disease management programs probably narrows gender differences in quality of care and survival among HF patients. Women with HF have less access to cardiologists, although this consultation is associated with better quality of care, particularly for women. Despite these known sex differences, recommendations for HF are the same for women and men, because prospective sex-specific clinical trials have not been performed. |
5,511 | Vagal modulation of heart rate variability during atrial fibrillation in pigs. | Atrial fibrillation (AF) is the most common sustained cardiac dysrhythmia and is associated with an increased risk for sudden cardiac death. The ventricular rhythm is irregular and displays both non-linear and linear patterns; however, it has not been determined whether vagally derived patterns are manifest within the irregular rhythm. Moreover, indices of increased vagal control are associated with reduced risk of sudden cardiac death. In this study, we sought to determine whether the ventricular rhythm pattern during AF is, in part, modulated by vagal activity. Vagal oscillations were forced at 0.15 Hz by neck suction in 12 pigs with sustained AF with and without glycopyrrolate (0.15 microg/kg, intravenously) vagal blockade. Vagal activity was evaluated using time- and frequency-domain heart rate variability measures. The standard deviation of RR intervals (SDRRI) was significantly increased during vagal activation compared with baseline (P = 0.006). Moreover, SDRRI correlated significantly with spectral power at 0.15 Hz during baseline (r = 0.90, P < .001) and vagal activation (r = 0.86, P < 0.05). Glycopyrrolate blocked the increase in SDRRI (P < 0.001) and blunted spectral power at 0.15 Hz (P < 0.05). These results indicate that: (1) power spectral analysis may be used to assess parasympathetic regulation during AF, and (2) vagal oscillations produce an entrainment of the ventricular rhythm during AF in pigs. |
5,512 | Assessment of mitral bioprostheses using cardiovascular magnetic resonance. | The orifice area of mitral bioprostheses provides important information regarding their hemodynamic performance. It is usually calculated by transthoracic echocardiography (TTE), however, accurate and reproducible determination may be challenging. Cardiovascular magnetic resonance (CMR) has been proven as an accurate alternative for assessing aortic bioprostheses. However, whether CMR can be similarly applied for bioprostheses in the mitral position, particularly in the presence of frequently coincident arrhythmias, is unclear. The aim of the study is to test the feasibility of CMR to evaluate the orifice area of mitral bioprostheses.</AbstractText>CMR planimetry was performed in 18 consecutive patients with mitral bioprostheses (n = 13 Hancock(R), n = 4 Labcore(R), n = 1 Perimount(R); mean time since implantation 4.5 +/- 3.9 years) in an imaging plane perpendicular to the transprosthetic flow using steady-state free-precession cine imaging under breath-hold conditions on a 1.5T MR system. CMR results were compared with pressure half-time derived orifice areas obtained by TTE.</AbstractText>Six subjects were in sinus rhythm, 11 in atrial fibrillation, and 1 exhibited frequent ventricular extrasystoles. CMR image quality was rated as good in 10, moderate in 6, and significantly impaired in 2 subjects. In one prosthetic type (Perimount(R)), strong stent artifacts occurred. Orifice areas by CMR (mean 2.1 +/- 0.3 cm2) and TTE (mean 2.1 +/- 0.3 cm2) correlated significantly (r = 0.94; p < 0.001). Bland-Altman analysis showed a 95% confidence interval from -0.16 to 0.28 cm2 (mean difference 0.06 +/- 0.11 cm2; range -0.1 to 0.3 cm2). Intra- and inter-observer variabilities of CMR planimetry were 4.5 +/- 2.9% and 7.9 +/- 5.2%.</AbstractText>The assessment of mitral bioprostheses using CMR is feasible even in those with arrhythmias, providing orifice areas with close agreement to echocardiography and low observer dependency. Larger samples with a greater variety of prosthetic types and more cases of prosthetic dysfunction are required to confirm these preliminary results.</AbstractText> |
5,513 | [Idiopathic premature ventricular complexes originating from the ventricular outflow tract: evaluation, prognosis and management]. | Idiopathic premature ventricular complexes originating from the ventricular outflow tract: evaluation, prognosis and management The prognosis of ventricular premature complexes (VPC) in the absence of heart disease is considered benign. VPC usually originate from the right or, less commonly, left ventricular outflow tract. QRS complexes therefore usually assume a left bundle branch block and inferior axis morphology. These VPC, particularly if very frequent (> 20,000 per day), may adversely affect left ventricular function and their suppression can restore normal function. Moreover, there is a clinical overlap with arrhythmogenic right ventricular dysplasia and this diagnosis should be considered when facing a left bundle branch block shaped VPC. However, the prognosis of outflow tract VPC is good for appropriately selected patients with normal left ventricular function, absence of syncope or ventricular tachycardia, and no evidence of cardiac disease. |
5,514 | Investigation of the relationship between venticular fibrillation duration and cardiac/neurological damage in a rabbit model of electrically induced arrhythmia. | To establish a simple, economic, and reliable alternating current (AC)-induced cardiac arrest (ACCA) model in rabbits for cardiopulmonary cerebral resuscitation research.</AbstractText>Ventricular fibrillation was induced in 27 New Zealand rabbits by external transthoracic AC, which were randomly divided into three groups according to the duration of untreated ACCA (ACCA-3 minutes, ACCA-5 minutes, and ACCA-8 minutes). After ACCA, all animals received cardiopulmonary resuscitation for 2 minutes and subsequent defibrillation until return of spontaneous circulation (ROSC). The troponin I levels were measured at 4 hours after ROSC. Animals died spontaneously or were killed at 72 hours after ROSC. The hippocampus were removed and fixed in 3% formalin. TdT-mediated dUTP-biotin nick end labeling and Nissl stainings were performed in 10-μm thickness coronal sections. Furthermore, two rabbits (without induction of ventricular fibrillation, cardiopulmonary resuscitation, and defibrillation) served as normal control group.</AbstractText>Mean survival times after ROSC were 48.57 hours ± 24.70 hours, 18.0 hours ± 15.13 hours, and 3.88 hours ± 2.39 hours for groups ACCA-3 minutes, ACCA-5 minutes, and ACCA-8 minutes, respectively. Survival was significantly different between ACCA-3 minutes and other two groups (p = 0.002 and p = 0.01). Neuronal necrosis and apoptosis were found in the hippocampus CA1, CA2, and CA3 areas of group ACCA-3 minutes. In contrast, neuronal necrosis and TdT-mediated dUTP-biotin nick end labeling positive cells were fewer in control animals.</AbstractText>The rabbits in group ACCA-3 minutes had significant neuronal damage with apoptosis in hippocampus CA1, CA2, and CA3 areas at 72 hours after ROSC and survived longer than those in other groups. The model we describe may be a simple, economic, and reliable model for experimental investigation on cardiopulmonary cerebral resuscitation.</AbstractText> |
5,515 | Novel insights into the role of the sympathetic nervous system in cardiac arrhythmogenesis. | It has long been recognized that increased sympathetic nerve activity during physiologic stress (exercise, swimming, emotion, arousal, loud noise, etc.) has profound influences on the electrical and contractile functions of the heart. In the severely predisposed heart, these stressors may lead to ventricular tachyarrhythmias and sudden death. Still little is known about the temporal relationship between instantaneous autonomic nerve activity and arrhythmias. There is a large variety of autonomically-driven arrhythmias, from serious ventricular tachycardia in pathological conditions to single supraventricular and ventricular extrasystolic beats in the healthy heart. The latter are considered harmless if occurring at low frequency. In the atria, mounting data indicate the presence of a sophisticated network of ganglionated plexi with major influences on cardiac function. The ablation of multiple such ganglia can suppress pulmonary vein potentials and atrial fibrillation. At the cellular level, recent studies have focused on the spatiotemporal details of cyclic nucleotide signaling influencing ion channel function during neurohumoral stimulation. We have come to understand that sarcolemmal ion channels and other electrogenic transporters are macromolecular complexes that interact with structural elements (other than the phospholipid bilayer) to promote regionalization and targeting by regulatory proteins. Compartmentation of these regulatory proteins in subdomains of the myocyte is increasingly recognized and thought to segregate the functional (including electrogenic) responses induced by different neuromediators and hormones. In this article, contemporary issues are discussed regarding arrhythmias that are triggered by influences from the neurocardiac interface, covering the field from the molecular genetic to the intact integrated level. Actual questions are listed per topic, and viewpoints are expressed. |
5,516 | BIVentricular versus right ventricular antitachycardia pacing to terminate ventricular tachyarrhythmias in patients receiving cardiac resynchronization therapy: the ADVANCE CRT-D Trial. | This multicenter, prospective, randomized, controlled, parallel trial compares the efficacy of biventricular (BIV) versus right ventricular (RV) antitachycardia pacing (ATP) in terminating all kinds of ventricular tachycardia (VT).</AbstractText>Five hundred twenty-six patients implanted with a cardiac resynchronization therapy defibrillator (CRT-D) device were enrolled and randomized 1:1 to either BIV (266) or RV (260) ATP (single burst 8 pulse, 88% coupling interval) and were followed up for 12 months.</AbstractText>During 12 months' follow-up, 1,077 ventricular episodes in 180 patients were detected and classified: 634 true VTs divided into 69 ventricular fibrillation (VF) (11%), 202 fast ventricular tachycardia (FVT) (32%), and 363 VT (57%). A comparable first ATP efficacy (BIV 65% vs RV 68%, P = .59) was observed in FVT + VT, in VT zone (BIV 62% vs RV 71%, P = .25), and in FVT zone (BIV 71% vs RV 61%, P = .34). A trend toward lower accelerations during ATP applied to FVT was observed in the BIV group (3.5% BIV vs 10.2% RV, P = .163). No syncope/presyncope occurred during ATP for FVT in the BIV group versus 4 events (3.2%) in the RV group (P = .016). biventricular ATP was more effective in treating FVT in coronary artery disease (CAD) patients (P = .032), whereas both modalities presented similar efficacy in patients with non-CAD etiology (P = .549).</AbstractText>Antitachycardia pacing is effective in patients implanted with a CRT-D device. No significant differences in efficacy emerged between BIV- and RV-delivered ATP in the general population, whereas BIV ATP seems to present a safer profile in ischemic patients.</AbstractText>Copyright 2010 Mosby, Inc. All rights reserved.</CopyrightInformation> |
5,517 | Risk factors and outcome of new-onset cardiac arrhythmias in vascular surgery patients. | The pathophysiology of new-onset cardiac arrhythmias is complex and may bring about severe cardiovascular complications. The relevance of perioperative arrhythmias during vascular surgery has not been investigated. The aim of this study was to assess risk factors and prognosis of new-onset arrhythmias during vascular surgery.</AbstractText>A total of 513 vascular surgery patients, without a history of arrhythmias, were included. Cardiac risk factors, inflammatory status, and left ventricular function (LVF; N-terminal pro-B-type natriuretic peptide and echocardiography) were assessed. Continuous electrocardiography (ECG) recordings for 72 hours were used to identify ischemia and new-onset arrhythmias: atrial fibrillation, sustained ventricular tachycardia, supraventricular tachycardia, and ventricular fibrillation. Logistic regression analysis was applied to identify preoperative risk factors for arrhythmias. Cox regression analysis assessed the impact of arrhythmias on cardiovascular event-free survival during 1.7 years.</AbstractText>New-onset arrhythmias occurred in 55 (11%) of 513 patients: atrial fibrillation, ventricular tachycardia, supraventricular tachycardia, and ventricular fibrillation occurred in 4%, 7%, 1%, and 0.2%, respectively. Continuous ECG showed myocardial ischemia and arrhythmias in 17 (3%) of 513 patients. Arrhythmia was preceded by ischemia in 10 of 55 cases. Increased age and reduced LVF were risk factors for the development of arrhythmias. Multivariate analysis showed that perioperative arrhythmias were associated with long-term cardiovascular events, irrespective of the presence of perioperative ischemia (hazard ratio 2.2, 95% CI 1.3-3.8, P = .004).</AbstractText>New-onset perioperative arrhythmias are common after vascular surgery. The elderly and patients with reduced LVF show arrhythmias. Perioperative continuous ECG monitoring helps to identify this high-risk group at increased risk of cardiovascular events and death.</AbstractText>Copyright 2010 Mosby, Inc. All rights reserved.</CopyrightInformation> |
5,518 | A multicenter, open-label study of vernakalant for the conversion of atrial fibrillation to sinus rhythm. | The efficacy and safety of vernakalant, a relatively atrial-selective antiarrhythmic agent, in converting atrial fibrillation (AF) to sinus rhythm (SR) were evaluated in this multicenter, open-label study of patients with AF lasting >3 hours and < or =45 days (RCT no. NCT00281554).</AbstractText>Adult patients with AF and an indication for conversion to SR received a 10-minute intravenous infusion of vernakalant (3 mg/kg). If after a 15-minute observation period AF was present, a second 10-minute infusion of intravenous vernakalant (2 mg/kg) was given. The primary efficacy end point was the proportion of patients with recent-onset AF (AF lasting >3 hours to < or =7 days) who converted to SR within 90 minutes of the start of the first infusion. Safety evaluations included vital signs, telemetry and Holter monitoring, 12-lead electrocardiography, clinical laboratory tests, physical examinations, and adverse events (AEs).</AbstractText>A total of 236 hemodynamically stable patients with AF received intravenous vernakalant. Among them, 167 (71%) had recent-onset AF and were eligible for the primary efficacy end point. Vernakalant rapidly converted recent-onset AF to SR in 50.9% of patients, with a median time to conversion of 14 minutes among responders. The most common AEs were dysgeusia, sneezing, and paresthesia. These occurred at the time of vernakalant infusion, were transient, and resolved spontaneously. Ten patients (4.2%) discontinued vernakalant treatment because of AEs, most commonly (in 4 of 10) hypotension. There were no episodes of torsades de pointes, ventricular fibrillation, or sustained ventricular tachycardia.</AbstractText>Vernakalant rapidly converted recent-onset AF to SR, was well tolerated, and may be a valuable therapeutic alternative for reestablishing SR in patients with recent-onset AF.</AbstractText>Copyright 2010 Mosby, Inc. All rights reserved.</CopyrightInformation> |
5,519 | Prevalence and prognostic significance of left ventricular dysfunction in patients presenting acutely with atrial fibrillation. | The prevalence and prognostic importance of CM occurring as a consequence of AF is poorly defined. This study investigated the incidence of CM in patients with AF, its clinical features and long-term outcomes. We demonstrated that CM is common in patients presenting acutely with newly diagnosed rapid AF, and carries a worse long-term prognosis. Systolic dysfunction was reversible in an important proportion of patients, suggesting a greater prevalence of rate-related CM in AF than has previously been postulated. This underscores the importance of appropriate rhythm management strategies and repeat imaging studies.</AbstractText>Atrial fibrillation (AF) may precipitate LV dysfunction, potentially leading to cardiomyopathy (CM). The prevalence and prognostic importance of CM occurring as a consequence of AF is poorly defined. We investigated the incidence of CM in patients with AF, its clinical features and long-term outcomes.</AbstractText>We reviewed 292 consecutive patients (average age 72 +/- 13yrs) presenting acutely with AF and tachycardia over a 3 year period from June 2004. Clinical details were obtained from medical records. CM was defined as ejection fraction (EF) </= 50% on index admission.</AbstractText>Echo was performed 93% of patients at index admission, and 69 (24%) had CM (average EF% = 37 +/- 11), 60 of which were newly diagnosed. Patients with CM had significantly higher presenting heart rate (141 +/- 19 vs. 132 +/- 23 bpm), larger end-diastolic (5.7 vs. 5.2 cm) and end-systolic (4.5 vs. 3.2 cm) dimensions, and larger left atrial size (4.6 vs. 4.3 cm) (p < 0.05 for all). They were also statistically more likely (p < 0.05) to be male, present with breathlessness, have a history of coronary disease, and be treated with digoxin and warfarin. Follow-up echo between 6 and 12 months was performed in 46% of patients with new CM, and average EF rose to 53 +/- 12%. At an average follow-up of 2.5 years, there was a significant increase in mortality in CM patients (16% vs. 9.5%, p < 0.05).</AbstractText>CM is common in patients presenting acutely with newly diagnosed rapid AF, and carries a worse long-term prognosis. Systolic dysfunction was reversible in an important proportion of patients, suggesting a greater prevalence of rate-related CM in AF than has previously been postulated. This underscores the importance of appropriate rhythm management strategies and repeat imaging studies.</AbstractText> |
5,520 | Effect of uncomplicated obesity on QT interval in young men. | QT prolongation and obesity are associated with ventricular arrhythmia and sudden cardiac death. The relationship between uncomplicated obesity and QT interval prolongation is not clear.</AbstractText>The aim of the study was to investigate the effects of uncomplicated obesity on QT interval in young men.</AbstractText>A total of 122 men, including 59 obese patients and 63 controls, were recruited into the study. Patients with hypertension, diabetes mellitus, and ischemic heart disease were ineligible. Body mass index (BMI) of all patients was calculated. QT interval was measured from the precordial lead--V5, and corrected QT (QTC) was calculated using the Bazett's formula.</AbstractText>Mean age, BMI, and waist circumference (WC) of obese patients and controls were as follows: 22.0 +/-3.0 years, 36.2 +/-2.2 kg/m(2), and 114 +/-8.1 cm; 22.6 +/-2.9 years, 24.7 +/-2.5 kg/m(2), and 81.6 +/-7.5 cm, respectively. There was a statistically significant difference between the obese and control groups with regard to BMI and WC (P <0.001). Furthermore, statistically significant differences were observed between the 2 groups in terms of QTC (407.9 +/-17.1 ms vs. 397.7 +/-14.0 ms, respectively, P <0.001), systolic (126.9 +/-8.2 mmHg vs. 114.2 +/-11.1 mmHg, respectively, P <0.001) and diastolic blood pressure (78.3 +/-4.5 mmHg vs. 66.9 +/-10 mmHg, respectively, P <0.001). There was a positive correlation between QTC interval and both WC (r = 0.357, P <0.001) and BMI (r = 0.424, P <0.001). There was no association between QTC and blood pressure.</AbstractText>Uncomplicated obesity in young men is associated with QT interval prolongation. Weight gain may inversely affect cardiac repolarization in uncomplicated obesity.</AbstractText> |
5,521 | [Hypertension and heart]. | Arterial hypertension often leads to diseases of kidneys, vessels and brain. Besides these end organ damages the changes of the heart are of important role. Substantial consequences of hypertension are microangiopathy, interstitial fibrosis and left ventricular hypertrophy. Hence, as an early stage diastolic dysfunction results. Due to longer persistent hypertension also systolic dysfunction develops. Clinically, patients suffer from angina pectoris, dyspnoea and cardiac arrhythmias (i.e. atrial arrhythmia, atrial fibrillation). The left ventricular hypertrophy also is associated with an increased risk of malignant ventricular arrhythmias. The risk of sudden cardiac death is raised as well, in particular in patients with dilated heart and reduced left ventricular ejection fraction. Well controlled antihypertensive therapy could lead to a regression of left ventricular hypertrophy. Hence, disorders and prognosis of the patients could be improved. |
5,522 | Sudden death in hypertrophic cardiomyopathy. | Hypertrophic cardiomyopathy (HCM) is regarded as the most common cause of sudden cardiac death in young people (including trained athletes). However, assessing sudden death (SD) risk and identifying the most appropriate candidates for prophylactic device therapy is a complex process compounded by the unpredictability of the underlying arrhythmogenic substrate, absence of a single dominant and quantitative risk maker for this heterogeneous disease, and also the difficulty encountered in assembling sufficiently powered prospective and randomized trials in large patient populations. Patients with multiple risk factors and most young patients with one strong and unequivocal risk marker can be considered candidates for primary prevention defibrillators. Despite certain limitations, the current risk factor algorithm (when combined with a measure of individual physician judgment) has proved to be an effective strategy for targeting high-risk status. This approach has served the HCM patient population well, as evidenced by the significant appropriate defibrillator intervention rates, although a very small proportion of patients without conventional risk factors may also be at risk for SD. Indeed, the introduction of implantable defibrillators to the HCM patient population represents a new paradigm for clinical practice, offering the only proven protection against SD by virtue of effectively terminating ventricular tachycardia/fibrillation. In the process, implantable defibrillators have altered the natural history of HCM, potentially providing the opportunity of normal or near-normal longevity for many patients. Prevention of SD is now an integral, albeit challenging, component of HCM management. |
5,523 | Hypertrophic cardiomyopathy: the early years. | Hypertrophic obstructive cardiomyopathy (HOCM) has four major features: (1) severe left ventricular hypertrophy, often most prominent in the basal interventricular septum; (2) frequent familial occurrence with autosomal dominant transmission; (3) occurrence of sudden cardiac death that is usually considered to be due to ventricular fibrillation; and (4) presence of hemodynamic evidence of labile intraventricular obstruction. The key papers describing the recognition of each of these features, as well as of various combinations of them, are reviewed in this paper. Particular attention is focused on the very frequent finding of marked lability of intraventricular obstruction. The recognition of this fourth and last major feature in 1959 makes 2009 the golden anniversary year marking completion of the description of the major features of HOCM. |
5,524 | Intramural dyssynchrony from acute right ventricular apical pacing in human subjects with normal left ventricular function. | Ventricular pacing causes early myocardial shortening at the pacing site and pre-stretch at the opposing ventricular wall. This contraction pattern is energetically inefficient and may lead to decreased cardiac function. This study was designed to describe the acute effects of right ventricular apical (RV(a)) pacing on dyssynchrony and systolic function in human subjects with normal left ventricular (LV) function and compare these effects to pacing from alternate ventricular sites. Patients (n = 26) undergoing an electrophysiology evaluation were studied during atrial pacing (AAI) and dual chamber pacing from the RV(a), left ventricular free wall (LV(fw)), and the combination of RV(a) and LV(fw) (BiV). Tissue Doppler imaging was used to measure intramural dyssynchrony by utilizing an integrated cross-correlation synchrony index (CCSI) from the apical 4-chamber view. RV(a) and BiV pacing significantly reduced systolic function as measured by longitudinal systolic contraction amplitude (SCA(long)) (p < 0.05) and LV velocity time integral (VTI) (p < 0.05) compared to AAI and LV(fw) pacing. RV(a) (and to a lesser extent BiV) pacing resulted in septal and lateral intramural dyssynchrony as indicated by significantly (p < 0.05) lower CCSI values as compared to AAI. CCSI was significantly (p < 0.05) worse during RV(a) than LV(fw) pacing. In patients with normal LV function, acute ventricular pacing in the RV(a) alone, or in conjunction with LV(fw) pacing (BiV), results in impaired regional and global LV systolic function and intramural dyssynchrony as compared to LV(fw) pacing alone. |
5,525 | A report of fetal demise during therapeutic hypothermia after cardiac arrest. | Therapeutic hypothermia is becoming the standard-of-care for coma following out-of-hospital cardiac arrest. Pregnancy has been considered a contraindication for therapeutic hypothermia.</AbstractText>Case report.</AbstractText>A 44-year-old woman presented after a witnessed out-of-hospital ventricular fibrillation cardiac arrest. She remained comatose upon hospital admission and was treated with induced hypothermia via surface cooling pads. An intrauterine pregnancy of 20 weeks gestation was discovered on admission. One day after admission, a stillborn fetus was spontaneously delivered. The patient made a good neurologic recovery and now lives at home with her family.</AbstractText>During pregnancy, beneficence toward the pregnant woman must be the primary ethical guideline in emergent, life-threatening situations. Pregnancy should not be a contraindication to therapeutic hypothermia following cardiac arrest.</AbstractText> |
5,526 | Abnormal atrial repolarization and depolarization contribute to the inducibility of atrial fibrillation in Brugada syndrome. | Brugada syndrome is often accompanied by atrial tachyarrhythmia, such as atrial fibrillation (AF). The aim of this study was to examine atrial vulnerability in patients with Brugada syndrome. Two groups of patients were compared: 18 patients with Brugada syndrome (Brugada syndrome group) and 11 age-matched patients with neither organic heart disease nor AF episodes (control group). Programmed electrical stimulation was performed from the right atrium (RA), and the effective refractory period of the right atrium (ERP-RA), interatrial conduction time (IACT), monophasic action potentials (MAPs) at the high RA, and the inducibility of AF lasting > 30 seconds were studied. MAP duration at 80% repolarization (MAPD(80)) was calculated. AF was induced with a single extrastimulus or double extrastimuli in all patients with Brugada syndrome but in none of the control patients. The ERP-RA did not differ between the groups. IACT at the shortest diastolic interval was significantly increased in the Brugada syndrome group compared to that in the control group. The maximum slope of the MAPD(80) restitution curve was significantly steeper in the Brugada syndrome group than in the control group (2.4 + or - 2.0 versus 0.82 + or - 0.36, P < 0.02). Ventricular fibrillation was induced with ventricular programmed stimulation in all Brugada syndrome patients. Both abnormal interatrial conduction and steep restitution of action potential duration may contribute to the atrial arrhythmogenicity in Brugada syndrome. |
5,527 | Tachycardia-induced cardiomyopathy: evaluation and therapeutic options. | Tachycardia-induced cardiomyopathy is caused by sustained rapid ventricular rates and is one of the well-known forms of reversible myocardial dysfunction. The diagnosis is usually made retrospectively after marked improvement in systolic function is noted following control of the heart rate. Physicians should be aware that patients with seemingly idiopathic systolic dysfunction may have tachycardia-induced cardiomyopathy and that controlling the heart rate may result in improvement or even complete restoration of systolic function. |
5,528 | Assessment of the post-implant final left ventricular lead position: a comparative study between radiographic and angiographic modalities. | Post-implant lateral and postero-anterior chest X-rays (CXR) are often utilized to determine the final LV lead tip position after cardiac resynchronization therapy (CRT). This study sought to compare post-implant standard CXRs with intra-procedural rotational coronary venous angiography (RCVA) to localize the final LV lead position.</AbstractText>Sixty-four patients undergoing CRT (69.2 ± 11.4 years; males 68.7%; ischemic cardiomyopathy 59.4%; NYHA class 2.9 ± 0.5 and LV ejection fraction 24% ± 9%) were included in the study. RCVA was done by recording a rapid 4-second isocentric cine-loop from RAO 55° to LAO 55° (120 frames). Conventional CXR method (CC) and a composite CXR strategy (CM) based on two-view CXR were separately compared with RCVA.</AbstractText>The most common pacing site was lateral (64.1%), followed by postero-lateral (23.4%) and antero-lateral (10.9%). In 73.4% (47) cases, the LV lead position was misclassified by CC as compared to RCVA. Among the 47 (73.4%) cases misclassified by CC approach, 35 had lateral LV lead position misclassified by CC as postero-lateral (77%), posterior (20%) and antero-lateral (3%). On the other hand, CM strategy classified the LV lead position correctly in 46 (71.9%) of the patients (p < 0.0001).</AbstractText>The composite CXR strategy is a useful method for post-procedure LV lead localization. Due to its simplicity, it can be widely applied in post-implant evaluation of LV lead position in CRT patients.</AbstractText> |
5,529 | Cilostazol attenuates ventricular arrhythmia induction and improves defibrillation efficacy in swine. | Previous reports demonstrated that cilostazol, a phosphodiesterase 3 inhibitor, affected cellular electrophysiology and reduced episodes of ventricular fibrillation (VF) in patients with Brugada syndrome. However, its effects on VF induction and defibrillation efficacy have never been investigated. We tested the hypothesis that cilostazol increases the VF threshold (VFT) and decreases the upper limit of vulnerability (ULV) and the defibrillation threshold (DFT). A total of 48 pigs were randomly assigned to defibrillation and VF induction studies. The diastolic pacing threshold (DPT), VFT, ULV, DFT, and effective refractory period were determined before and after the infusion of cilostazol at 6 mg/kg, 3 mg/kg, or vehicle. The DPT was significantly increased after administration of 3 and 6 mg/kg cilostazol. The ULV and DFT were significantly decreased after administration of 6 mg/kg cilostazol only. The ULV in the 6 mg/kg group had 12% lower peak voltage and 25% lower total energy, and the DFT had 13% lower peak voltage and 25% lower total energy. The VFT was not altered in any experimental group. This study shows that cilostazol administration significantly increased the DPT, which was associated with significantly reduced DFT and ULV. |
5,530 | [ICD therapy for the primary prevention of sudden cardiac arrest. The patient after a myocardial infarction]. | ICD therapy represents a major advance in the treatment of patients with severely impaired left ventricular function after myocardial infarction. While an ICD implantation also remains a valuable option late (>5 years) after myocardial infarction, patients early after this event are at a competitive risk of arrhythmogenic and nonarrhythmogenic cardiac death. Prevention of sudden cardiac death in patients early after myocardial infarction, therefore, just converts the mode of death in a significant number of patients from sudden to nonsudden cardiac death (conversion theory). In patients with a left ventricular ejection fraction (LVEF) of < or =30% after myocardial infarction, implantation of the ICD should, therefore, be postponed to at least 30-40 days after the event. It is, however, not clear how the risk of sudden cardiac death should be approached during this post infarction phase. Similarly, it is not clear if patients with a reduced LVEF post infarction and additional specific risks (nonsustained ventricular tachycardia, atrial fibrillation, bundle branch block, etc.) beyond this single criterion may also benefit from ICD implantation and which risk factors may be relevant. In any case, ICD therapy should avoid right ventricular pacing and shock discharges whenever possible. |
5,531 | A first city-wide early defibrillation project in a German city: 5-year results of the Bochum against sudden cardiac arrest study. | Immediate defibrillation is the decisive determinant of prognosis in patients suffering from cardiac/circulatory arrest caused by ventricular fibrillation (VF). Therefore, various national and international associations recommend that first responders use defibrillators as soon as possible and also recommend public access to early defibrillation programmes. Here we report the results of the first city-wide early defibrillation project in a large German urban area.</AbstractText>There were 155 automated external defibrillators (AEDs) put into operation in the Bochum municipal area, and 6,294 people took part in cardiopulmonary resuscitation (CPR) and AED training. Free, accessible AEDs were installed in places with large volumes of people. Additionally, emergency forces were progressively equipped with AEDs.</AbstractText>Twelve AED administrations prior to the arrival of an emergency physician were recorded and analysed over a period of 5 years (08/2004-08/2009). Rhythm analysis via AED demonstrated VF in seven cases, non-malignant dysrhythmias in four cases and asystole in one case. Two of the seven patients with VF were successfully defibrillated and survived cardiac/circulatory arrest without any neurological sequelae. Eight of the 12 AED applications were performed by laymen. The mean time between switching the unit on and applying the electrodes to the patient was 39 seconds (SD +/-20 sec). On average, another 20 seconds elapsed before the AED recommendation of "shock delivery" was displayed, and a total of 96 seconds elapsed before shock administration (+/- 56 sec).</AbstractText>Consistent with other reports, our findings show that the organisation of a city-wide initiative by a project office combining public access and first-responder defibrillation programmes can be safe, feasible and successful. Our experiences confirm that strategic planning of AED placement is a prerequisite for successful, cost-effective resuscitation.</AbstractText> |
5,532 | Electrophysiologic study: its predictive value for ventricular arrhythmias. | Studies have shown the predictive value of inducible ventricular tachycardia and clinical arrhythmia in patients who have structural heart disease. We examined the possible predictive value of electrophysiologic study before the placement of an implantable cardioverter-defibrillator. Our retrospective study group comprised 315 patients who had ventricular tachycardia that was inducible during electrophysiologic study and who had undergone at least 1 month of follow-up (247 men; mean age, 66.9 +/- 13.5 yr; mean follow-up, 24.9 +/- 14.8 mo). Recorded characteristics included induced ventricular tachycardia cycle length, atrio-His and His-ventricular electrograms, PR and QT intervals, QRS duration, and drug therapy. Of the 315 patients, 97 experienced ventricular arrhythmia during the follow-up period, as registered by 184 of more than 400 interrogations. There were 187 episodes of ventricular arrhythmia (tachycardia, 178; fibrillation, 9) during 652.5 person-years of follow-up. Subjects with a cycle length > or =240 msec were more likely to have an earlier 1st arrhythmia than those with a cycle length <240 msec (P=0.032). A quarter of the subjects with a cycle length > or =240 msec had their 1st arrhythmia by 19.14 months, compared with 23.8 months for a quarter of the subjects with a cycle length <240 msec (P <0.032). Among the electrophysiologic characteristics examined, inducible ventricular tachycardia with a cycle length > or =240 msec is predictive of appropriate implantable cardioverter-defibrillator therapy at an earlier time. This may have prognostic implications that warrant implantable cardioverter-defibrillator programming to enable appropriate antitachycardia pacing in this group of patients. |
5,533 | Review of the management of sudden cardiac arrest on the football field. | Football is the most popular sport on earth. When a young, fit popular player suddenly collapses and dies during play, the tragic event is frequently screened and publicised worldwide. The reported incidence of sudden cardiac arrest (SCA) varies from 1:65,000 to 1:200,000 athletes. A broad spectrum of cardiac and non-cardiac causes have been implicated, and regular precompetition medical assessments are recommended as a preventive measure. Immediate cardiopulmonary resuscitation and early defibrillation is the treatment for SCA. High success rates can be achieved if this is initiated promptly, preferably within seconds of the arrest. Trained medical responders must be allowed to respond, ideally with a defibrillator (manual or automated) in hand, to a player who suddenly and unexpectedly collapses and remains unresponsive on the field. Immediate defibrillation of a pulseless ventricular tachycardia or ventricular fibrillation, within 1 to 2 min of onset, has a successful cardioversion rate exceeding 90%. Medical responders should be well trained and rehearsed in the recognition of SCA, including distractors such as seizures, myoclonic jerks and agonal (gasping) breathing. Prompt initiation of chest compressions on the field, together with early defibrillation, will result in many athletes' lives being saved by immediate implementation of these simple recommendations. |
5,534 | Influence of the On-X mechanical prosthesis on intermediate-term major thromboembolism and hemorrhage: a prospective multicenter study. | Long-term thromboembolic and hemorrhagic outcomes after mechanical valve replacement have been well described; however, few studies have described these outcomes after valve replacement with the On-X mechanical prosthesis (On-X Life Technologies, Inc, Austin, Tex).</AbstractText>Between 2003 and 2008, 737 patients underwent either aortic valve replacement (n = 400), mitral valve replacement (n = 282), or double-valve replacement (n = 55). Longitudinal performance, freedom evaluation, and risk analysis were assessed with regard to major thromboembolism and hemorrhage. Risk modeling was performed with 16 variables inclusive of age, atrial fibrillation, concomitant coronary artery bypass grafting, New York Heart Association class, and ventricular dysfunction.</AbstractText>Early mortality was 2.5% (n = 10) for aortic valve replacement and 3.2% (n = 9) for mitral valve replacement. Late mortality for aortic valve replacement was 4.8% per patient-year and 6.0% per patient-year for mitral valve replacement. Five-year freedom from major thromboembolism was 96.5% ± 1.2% for aortic valve replacement and 97.7% ± 0.9% for mitral valve replacement. Five-year freedom from hemorrhage was 93.6% ± 1.8% for aortic valve replacement and 95.7% ± 1.5% for mitral valve replacement. Concomitant coronary artery bypass grafting was predictive of major thromboembolism after aortic valve replacement (hazard ratio, 5.3; P = .02) and antithrombotic hemorrhage after mitral valve replacement (hazard ratio, 4.7; P = .03). No other independent predictors of major thromboembolism or hemorrhage were identified. One thrombosed mitral prosthesis was observed after deliberate discontinuation of anticoagulation. The major thromboembolic events occurred with variation of international normalized ratio levels inclusive of subtherapeutic levels. The majority of hemorrhagic events occurred with high international normalized ratio levels.</AbstractText>The On-X mechanical prosthesis provides favorable intermediate-term results with regard to major thromboembolism and hemorrhage.</AbstractText>Copyright © 2010 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.</CopyrightInformation> |
5,535 | Idiopathic ventricular fibrillation in a 10-year-old boy: technical aspects of radiofrequency ablation and utility of antiarrhythmic therapy. | Idiopathic ventricular fibrillation (VF) is defined as spontaneous VF in the absence of structural heart disease. No prior reports exist addressing the technical aspects of idiopathic VF ablation in a child. We present the case of a 10-year-old boy with idiopathic VF, who presented a unique management challenge, particularly as regards the technical aspects of the ablation procedure. Ablation of idiopathic VF is feasible in a 10-year-old boy and oral quinidine seems more effective than other antiarrhythmic drugs in this condition. |
5,536 | Left ventricular lateral annulus and left atrial free-wall velocity time integral indicate thromboembolism in patients with rheumatic atrial fibrillation. | Low wall motion and stasis increase the likelihood of clot formation. We hypothesized that tissue Doppler indices of left atrial (LA) motion are reduced in the presence of LA thrombi and may be predictive for clot formation in patients with atrial fibrillation (AF).</AbstractText>We did an observational study for 3 years in 118 patients with rheumatic mitral valve disease in chronic AF who had not received anticoagulation, with (Group 1, n = 36) and without (Group 2, n = 82) thromboembolism. Pulsed tissue Doppler systolic velocities and velocity time integrals (VTIs) were measured in all four chambers. A mean LA VTI was calculated. LA strain during ventricular systole was calculated using VTI and distance between two LA locations.</AbstractText>Logistic regression analysis showed that, after adjusting for age, gender, diabetes, hypertension, LA size, and left ventricular (LV) ejection fraction, mean LA VTI [Odds ratio (OR) 0.69, 95%CI (0.56-0.86, P = 0.03)] and lateral mitral annulus VTI [OR 0.15 (0.04-0.56, P = 0.03)] were associated with clot formation. The addition of these two parameters to the conventional risk factors increased the ability to predict thromboembolism (Nagelkerke R² = 0.32-0.50, P = 0.01; area under the curve 0.83 by receiver operating characteristic analysis, P = 0.01). LA strain also had potential to indicate clot formation (0.9 ± 13.8 vs. -8.2 ± 15.1%, group 1 vs. 2, respectively, P = 0.01).</AbstractText>Patients with chronic AF and thromboembolism have reduced LA and LV motion independently of LA size and LV ejection fraction. Tissue Doppler parameters may have potential to predict clot formation in these patients.</AbstractText>© 2010, Wiley Periodicals, Inc.</CopyrightInformation> |
5,537 | Cold aortic flush and chest compressions enable good neurologic outcome after 15 mins of ventricular fibrillation in cardiac arrest in pigs. | The induction of deep cerebral hypothermia via ice-cold saline aortic flush during prolonged ventricular fibrillation cardiac arrest, followed by hypothermic stasis and delayed resuscitation (emergency preservation and resuscitation), improved neurologic outcome after cardiac arrest in pigs, as compared to conventional resuscitation. We hypothesized that emergency preservation and resuscitation with chest compressions would further improve outcome in the same model.</AbstractText>Prospective experimental study.</AbstractText>University research laboratory.</AbstractText>: Twenty-four female, large, white breed pigs (27-37 kg).</AbstractText>Fifteen minutes of ventricular fibrillation cardiac arrest were followed by 20 mins of resuscitation with chest compressions (control, n = 8), deep cerebral hypothermia via 200 mL/kg 4 degrees C saline aortic flush and hypothermic stasis (emergency preservation and resuscitation, n = 8), and emergency preservation and resuscitation combined with chest compressions (emergency preservation and resuscitation plus chest compressions, n = 8). At 35 mins after cardiac arrest, cardiopulmonary bypass was initiated, followed by defibrillation. Mild hypothermia was continued for 20 hrs. Pigs were evaluated after 9 days using a neurologic deficit (neurologic deficit score: 100% = brain dead; 0%-10% = normal) and an overall performance category score (overall performance category score: 1 = normal; 2 = slightly handicapped; 3 = severely handicapped; 4 = comatose; 5 = dead/brain dead).</AbstractText>Brain temperature decreased from 38.5 degrees C to 15.3 degrees C +/- 3.3 degrees C in the emergency preservation and resuscitation group, and to 11.3 degrees C +/- 1.2 degrees C in the emergency preservation and resuscitation plus chest compressions group. In the control group, restoration of spontaneous circulation was achieved in four out of eight pigs, and one survived to 9 days. In the emergency preservation and resuscitation group, restoration of spontaneous circulation was achieved in seven out of eight pigs and five survived; in the emergency preservation and resuscitation plus chest compressions group, all had restoration of spontaneous circulation and seven survived (restoration of spontaneous circulation, p = .08). Neurologic outcome for (median and interquartile range) the control group included overall performance category score of 3, neurologic deficit score of 45%; for the emergency preservation and resuscitation group, overall performance category score was 3 (2-5) and neurologic deficit score was 45% (36; 50) and in the emergency preservation and resuscitation plus chest compressions group, overall performance category score was 2 (1-3) and neurologic deficit score was 13% (5; 21) (overall performance category score, p = .04; neurologic deficit score emergency preservation and resuscitation vs. emergency preservation and resuscitation plus chest compressions, p = .003).</AbstractText>Emergency preservation and resuscitation by deep cerebral hypothermia combined with chest compressions during prolonged cardiac arrest in pigs are feasible and improve neurologic outcome.</AbstractText> |
5,538 | The R820W mutation in the MYBPC3 gene, associated with hypertrophic cardiomyopathy in cats, causes hypertrophic cardiomyopathy and left ventricular non-compaction in humans. | The R820W mutation in the MYBPC3 gene has been associated with the development of hypertrophic cardiomyopathy (HCM) in rag-doll cats, but had not been described in humans.</AbstractText>To describe the phenotype associated with the R820W mutation identified in a human family.</AbstractText>The R820W was identified by direct sequencing of the MYBPC3 gene in a 47 year old woman with HCM and left ventricular non-compaction (LVNC). Clinical and genetic studies of the R820W mutation were performed in her family.</AbstractText>The index patient was homozygous for the mutation and had no additional mutations in the main sarcomeric genes (MYH7, TNNT2, TNNI3, and TPM1). She had HCM with LVNC and normal systolic function. One brother had died suddenly at age 43 years. Another brother diagnosed of LVNC with severe systolic dysfunction and a cardiac arrest was also homozygous for the mutation. One heterozygous 31 year old sister, and three heterozygous sons of the index (ages 14, 20 and 23 years old) were clinically unaffected. The father of the index was apparently healthy and her mother had atrial fibrillation and an electrocardiographic diagnosis of left ventricular hypertrophy at age 86 years.</AbstractText>The R820W mutation in the MYBPC3 gene, previously associated with HCM in rag-doll cats, causes both HCM and LVNC in homozygous human carriers, with mild or null clinical expression in heterozygous carriers.</AbstractText>Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
5,539 | Freedom SOLO valve: early- and intermediate-term results of a single centre's first 100 cases. | The Freedom SOLO aortic valve is a bovine pericardial stentless valve, which requires only one suture line. The aim of our single-centre retrospective study was to assess postoperative and intermediate-term haemodynamic results of the first 100 consecutively implanted valves.</AbstractText>One hundred patients (39 male and 61 female) underwent aortic valve replacement with a Freedom SOLO from November 2006 to January 2008. Their clinical, operative, platelet levels, echocardiography and follow-up data were prospectively recorded. All but two patients were available for follow-up (98% completeness), which averaged 12.6 ± 5.06 months.</AbstractText>Associated procedures were performed in 38 patients (38%): 27 coronary artery bypass grafting (CABG), 11 mitral valve replacement, 11 septal myectomy and one ablation for atrial fibrillation. The mean age at the time of surgery was 77.2 ± 6.43 years. The mean European System for Cardiac Operative Risk Evaluation (EuroSCORE) was 8.05 ± 2.07. Mean cross-clamp time of isolated valve replacements was 51.27 ± 4.7 min and 63.18 ± 21.7 min with associated procedures. The mean implanted valve size was 23.5 ± 1.9 mm. One patient was re-operated for bleeding, two for pericardial effusion and 39 were transfused. The overall hospital mortality was 3%. One patient died suddenly postoperatively, and a second due to a fatal atrio-ventricular block. A third patient died following a subdural bleed. Three patients required a pacemaker before hospital discharge. The overall patient survival was 97 ± 2.26% at 1 year. Echocardiographic results preoperative, 8 days postoperative and 12 months after surgery showed mean transvalvular gradients of 50.6 ± 15.3, 15.6 ± 5.2 and 11.5 ± 3.8 mm Hg, respectively, and mean left ventricular ejection fractions of 37.9 ± 10.2%, 44 ± 15.2% and 53.6 ± 10.4%. Effective orifice area index for valve sizes 19, 21, 23, 25 and 27 were 0.91 ± 0.08, 0.97 ± 0.1, 1.08 ± 0.07, 1.53 ± 0.12 and 1.57 ± 0.1cm(2)m(-2), respectively. There were three early non-structural dysfunctions (grade 1) of regurgitation, which remained stable at 12 months.</AbstractText>Freedom SOLO valve has very good early- and intermediate-term results. Short implantation times and its haemodynamic performances, particularly in small diameters, allow us to use it by first intention in older and often sicker patients. These results must be confirmed by long-term outcomes.</AbstractText>Copyright © 2010 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.</CopyrightInformation> |
5,540 | Ventricular fibrillation diagnosed during electrophysiological study for non-sustained tachycardia.<Pagination><StartPage>593</StartPage><EndPage>596</EndPage><MedlinePgn>593-6</MedlinePgn></Pagination><Abstract><AbstractText>Ventricular fibrillation diagnoses such as Brugada syndrome pose a risk of sudden incapacitation or death in aircrew. This case report presents a 44-yr-old male fighter pilot who unexpectedly developed ventricular fibrillation (VF) during an electrophysiological study (EPS) prior to therapy for non-sustained ventricular tachycardia (nsVT). The initial aeromedical disposition for this case was "qualified for flying duties". with the restriction that he must fly with another pilot due to repeatedly observed nsVT. This pilot wanted to return to flight duty in single-seat aircraft without any restrictions. Therefore, this patient decided to undergo catheter therapy for nsVT. Unexpectedly, not VT but VF was induced by catheter manipulation during EPS. Pilsicainide-induced coved-type ST wave elevation consistent with Brugada syndrome was noted in this patient's electrocardiogram. He was ultimately disqualified due to the diagnosis of VF. This report suggests EPS on rare occasions may uncover another severe disease similar to this case report.</AbstractText></Abstract><AuthorList CompleteYN="Y"><Author ValidYN="Y"><LastName>Hisada</LastName><ForeName>Tetsuya</ForeName><Initials>T</Initials><AffiliationInfo><Affiliation>Department of Preventive Medicine and Public Health, National Defense Medical College, Tokorozawa, Saitama, Japan. [email protected]</Affiliation></AffiliationInfo></Author><Author ValidYN="Y"><LastName>Miyagawa</LastName><ForeName>Takashi</ForeName><Initials>T</Initials></Author><Author ValidYN="Y"><LastName>Yakushiji</LastName><ForeName>Tadayuki</ForeName><Initials>T</Initials></Author><Author ValidYN="Y"><LastName>Tsujimoto</LastName><ForeName>Tetsuya</ForeName><Initials>T</Initials></Author><Author ValidYN="Y"><LastName>Sakai</LastName><ForeName>Masao</ForeName><Initials>M</Initials></Author><Author ValidYN="Y"><LastName>Adachi</LastName><ForeName>Takeshi</ForeName><Initials>T</Initials></Author><Author ValidYN="Y"><LastName>Ikewaki</LastName><ForeName>Katsunori</ForeName><Initials>K</Initials></Author><Author ValidYN="Y"><LastName>Ogata</LastName><ForeName>Katsuhiko</ForeName><Initials>K</Initials></Author><Author ValidYN="Y"><LastName>Ohsuzu</LastName><ForeName>Fumitaka</ForeName><Initials>F</Initials></Author><Author ValidYN="Y"><LastName>Sakurai</LastName><ForeName>Yutaka</ForeName><Initials>Y</Initials></Author></AuthorList><Language>eng</Language><PublicationTypeList><PublicationType UI="D002363">Case Reports</PublicationType><PublicationType UI="D016428">Journal Article</PublicationType></PublicationTypeList></Article><MedlineJournalInfo><Country>United States</Country><MedlineTA>Aviat Space Environ Med</MedlineTA><NlmUniqueID>7501714</NlmUniqueID><ISSNLinking>0095-6562</ISSNLinking></MedlineJournalInfo><ChemicalList><Chemical><RegistryNumber>0</RegistryNumber><NameOfSubstance UI="D000889">Anti-Arrhythmia Agents</NameOfSubstance></Chemical><Chemical><RegistryNumber>98PI200987</RegistryNumber><NameOfSubstance UI="D008012">Lidocaine</NameOfSubstance></Chemical><Chemical><RegistryNumber>AV0X7V6CSE</RegistryNumber><NameOfSubstance UI="C042288">pilsicainide</NameOfSubstance></Chemical></ChemicalList><CitationSubset>IM</CitationSubset><MeshHeadingList><MeshHeading><DescriptorName UI="D000328" MajorTopicYN="N">Adult</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D000889" MajorTopicYN="N">Anti-Arrhythmia Agents</DescriptorName><QualifierName UI="Q000627" MajorTopicYN="N">therapeutic use</QualifierName></MeshHeading><MeshHeading><DescriptorName UI="D053840" MajorTopicYN="N">Brugada Syndrome</DescriptorName><QualifierName UI="Q000175" MajorTopicYN="Y">diagnosis</QualifierName></MeshHeading><MeshHeading><DescriptorName UI="D004562" MajorTopicYN="N">Electrocardiography</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D006801" MajorTopicYN="N">Humans</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D007564" MajorTopicYN="N" Type="Geographic">Japan</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D008012" MajorTopicYN="N">Lidocaine</DescriptorName><QualifierName UI="Q000031" MajorTopicYN="N">analogs & derivatives</QualifierName><QualifierName UI="Q000627" MajorTopicYN="N">therapeutic use</QualifierName></MeshHeading><MeshHeading><DescriptorName UI="D008297" MajorTopicYN="N">Male</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D016272" MajorTopicYN="Y">Occupational Health</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D017180" MajorTopicYN="N">Tachycardia, Ventricular</DescriptorName><QualifierName UI="Q000175" MajorTopicYN="Y">diagnosis</QualifierName><QualifierName UI="Q000503" MajorTopicYN="N">physiopathology</QualifierName></MeshHeading><MeshHeading><DescriptorName UI="D013997" MajorTopicYN="N">Time Factors</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D014693" MajorTopicYN="N">Ventricular Fibrillation</DescriptorName><QualifierName UI="Q000175" MajorTopicYN="Y">diagnosis</QualifierName><QualifierName UI="Q000503" MajorTopicYN="N">physiopathology</QualifierName></MeshHeading></MeshHeadingList></MedlineCitation><PubmedData><History><PubMedPubDate PubStatus="entrez"><Year>2010</Year><Month>6</Month><Day>15</Day><Hour>6</Hour><Minute>0</Minute></PubMedPubDate><PubMedPubDate PubStatus="pubmed"><Year>2010</Year><Month>6</Month><Day>15</Day><Hour>6</Hour><Minute>0</Minute></PubMedPubDate><PubMedPubDate PubStatus="medline"><Year>2011</Year><Month>3</Month><Day>26</Day><Hour>6</Hour><Minute>0</Minute></PubMedPubDate></History><PublicationStatus>ppublish</PublicationStatus><ArticleIdList><ArticleId IdType="pubmed">20540453</ArticleId><ArticleId IdType="doi">10.3357/asem.2723.2010</ArticleId></ArticleIdList></PubmedData></PubmedArticle><PubmedArticle><MedlineCitation Status="MEDLINE" Owner="NLM"><PMID Version="1">20540356</PMID><DateCompleted><Year>2010</Year><Month>06</Month><Day>22</Day></DateCompleted><DateRevised><Year>2016</Year><Month>10</Month><Day>20</Day></DateRevised><Article PubModel="Print"><Journal><ISSN IssnType="Print">0869-6047</ISSN><JournalIssue CitedMedium="Print"><Issue>4</Issue><PubDate><Year>2010</Year></PubDate></JournalIssue><Title>Vestnik Rossiiskoi akademii meditsinskikh nauk</Title><ISOAbbreviation>Vestn Ross Akad Med Nauk</ISOAbbreviation></Journal>[Afobasol antifibrillation activity in animals with the intact and denervated myocardium]. | Ventricular fibrillation diagnoses such as Brugada syndrome pose a risk of sudden incapacitation or death in aircrew. This case report presents a 44-yr-old male fighter pilot who unexpectedly developed ventricular fibrillation (VF) during an electrophysiological study (EPS) prior to therapy for non-sustained ventricular tachycardia (nsVT). The initial aeromedical disposition for this case was "qualified for flying duties". with the restriction that he must fly with another pilot due to repeatedly observed nsVT. This pilot wanted to return to flight duty in single-seat aircraft without any restrictions. Therefore, this patient decided to undergo catheter therapy for nsVT. Unexpectedly, not VT but VF was induced by catheter manipulation during EPS. Pilsicainide-induced coved-type ST wave elevation consistent with Brugada syndrome was noted in this patient's electrocardiogram. He was ultimately disqualified due to the diagnosis of VF. This report suggests EPS on rare occasions may uncover another severe disease similar to this case report.</Abstract><AuthorList CompleteYN="Y"><Author ValidYN="Y"><LastName>Hisada</LastName><ForeName>Tetsuya</ForeName><Initials>T</Initials><AffiliationInfo><Affiliation>Department of Preventive Medicine and Public Health, National Defense Medical College, Tokorozawa, Saitama, Japan. [email protected]</Affiliation></AffiliationInfo></Author><Author ValidYN="Y"><LastName>Miyagawa</LastName><ForeName>Takashi</ForeName><Initials>T</Initials></Author><Author ValidYN="Y"><LastName>Yakushiji</LastName><ForeName>Tadayuki</ForeName><Initials>T</Initials></Author><Author ValidYN="Y"><LastName>Tsujimoto</LastName><ForeName>Tetsuya</ForeName><Initials>T</Initials></Author><Author ValidYN="Y"><LastName>Sakai</LastName><ForeName>Masao</ForeName><Initials>M</Initials></Author><Author ValidYN="Y"><LastName>Adachi</LastName><ForeName>Takeshi</ForeName><Initials>T</Initials></Author><Author ValidYN="Y"><LastName>Ikewaki</LastName><ForeName>Katsunori</ForeName><Initials>K</Initials></Author><Author ValidYN="Y"><LastName>Ogata</LastName><ForeName>Katsuhiko</ForeName><Initials>K</Initials></Author><Author ValidYN="Y"><LastName>Ohsuzu</LastName><ForeName>Fumitaka</ForeName><Initials>F</Initials></Author><Author ValidYN="Y"><LastName>Sakurai</LastName><ForeName>Yutaka</ForeName><Initials>Y</Initials></Author></AuthorList><Language>eng</Language><PublicationTypeList><PublicationType UI="D002363">Case Reports</PublicationType><PublicationType UI="D016428">Journal Article</PublicationType></PublicationTypeList></Article><MedlineJournalInfo><Country>United States</Country><MedlineTA>Aviat Space Environ Med</MedlineTA><NlmUniqueID>7501714</NlmUniqueID><ISSNLinking>0095-6562</ISSNLinking></MedlineJournalInfo><ChemicalList><Chemical><RegistryNumber>0</RegistryNumber><NameOfSubstance UI="D000889">Anti-Arrhythmia Agents</NameOfSubstance></Chemical><Chemical><RegistryNumber>98PI200987</RegistryNumber><NameOfSubstance UI="D008012">Lidocaine</NameOfSubstance></Chemical><Chemical><RegistryNumber>AV0X7V6CSE</RegistryNumber><NameOfSubstance UI="C042288">pilsicainide</NameOfSubstance></Chemical></ChemicalList><CitationSubset>IM</CitationSubset><MeshHeadingList><MeshHeading><DescriptorName UI="D000328" MajorTopicYN="N">Adult</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D000889" MajorTopicYN="N">Anti-Arrhythmia Agents</DescriptorName><QualifierName UI="Q000627" MajorTopicYN="N">therapeutic use</QualifierName></MeshHeading><MeshHeading><DescriptorName UI="D053840" MajorTopicYN="N">Brugada Syndrome</DescriptorName><QualifierName UI="Q000175" MajorTopicYN="Y">diagnosis</QualifierName></MeshHeading><MeshHeading><DescriptorName UI="D004562" MajorTopicYN="N">Electrocardiography</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D006801" MajorTopicYN="N">Humans</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D007564" MajorTopicYN="N" Type="Geographic">Japan</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D008012" MajorTopicYN="N">Lidocaine</DescriptorName><QualifierName UI="Q000031" MajorTopicYN="N">analogs & derivatives</QualifierName><QualifierName UI="Q000627" MajorTopicYN="N">therapeutic use</QualifierName></MeshHeading><MeshHeading><DescriptorName UI="D008297" MajorTopicYN="N">Male</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D016272" MajorTopicYN="Y">Occupational Health</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D017180" MajorTopicYN="N">Tachycardia, Ventricular</DescriptorName><QualifierName UI="Q000175" MajorTopicYN="Y">diagnosis</QualifierName><QualifierName UI="Q000503" MajorTopicYN="N">physiopathology</QualifierName></MeshHeading><MeshHeading><DescriptorName UI="D013997" MajorTopicYN="N">Time Factors</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D014693" MajorTopicYN="N">Ventricular Fibrillation</DescriptorName><QualifierName UI="Q000175" MajorTopicYN="Y">diagnosis</QualifierName><QualifierName UI="Q000503" MajorTopicYN="N">physiopathology</QualifierName></MeshHeading></MeshHeadingList></MedlineCitation><PubmedData><History><PubMedPubDate PubStatus="entrez"><Year>2010</Year><Month>6</Month><Day>15</Day><Hour>6</Hour><Minute>0</Minute></PubMedPubDate><PubMedPubDate PubStatus="pubmed"><Year>2010</Year><Month>6</Month><Day>15</Day><Hour>6</Hour><Minute>0</Minute></PubMedPubDate><PubMedPubDate PubStatus="medline"><Year>2011</Year><Month>3</Month><Day>26</Day><Hour>6</Hour><Minute>0</Minute></PubMedPubDate></History><PublicationStatus>ppublish</PublicationStatus><ArticleIdList><ArticleId IdType="pubmed">20540453</ArticleId><ArticleId IdType="doi">10.3357/asem.2723.2010</ArticleId></ArticleIdList></PubmedData></PubmedArticle><PubmedArticle><MedlineCitation Status="MEDLINE" Owner="NLM"><PMID Version="1">20540356</PMID><DateCompleted><Year>2010</Year><Month>06</Month><Day>22</Day></DateCompleted><DateRevised><Year>2016</Year><Month>10</Month><Day>20</Day></DateRevised><Article PubModel="Print"><Journal><ISSN IssnType="Print">0869-6047</ISSN><JournalIssue CitedMedium="Print"><Issue>4</Issue><PubDate><Year>2010</Year></PubDate></JournalIssue><Title>Vestnik Rossiiskoi akademii meditsinskikh nauk</Title><ISOAbbreviation>Vestn Ross Akad Med Nauk</ISOAbbreviation></Journal><ArticleTitle>[Afobasol antifibrillation activity in animals with the intact and denervated myocardium].</ArticleTitle><Pagination><StartPage>45</StartPage><EndPage>48</EndPage><MedlinePgn>45-8</MedlinePgn></Pagination><Abstract>The influence of afobasol on threshold electrical fibrillation of the heart was studied in experiments on narcotized cats. It significantly elevated the cardiac fibrillation threshold in animals with intact myocardium and resembled class 1B anti-arrhythmic drug lidocaine in terms of this activity. Similar results were obtained using cats with denervated myocardium. These observations indicate that in the model of electrical fibrillation of the heart afobasol has marked antifibrillation action mediated through cardiomyocytes. This inference was confirmed by the studies of afobasol effects on cardiac rhythm variability in rats with acute myocardial ischemia. It is supposed that afobasol prevents cardiac fibrillation acting as an agonist of cytosolic sigma-1 receptors in cardiomyocytes |
5,541 | Structure-based virtual screening and electrophysiological evaluation of new chemotypes of K(v)1.5 channel blockers. | Atrial fibrillation (AF) is the most prevalent nonfatal cardiac rhythm disorder associated with an increased risk of heart failure and stroke. Considering the ventricular side effects induced by anti-arrhythmic agents in current use, K(v)1.5 channel blockers have attracted a great deal of deliberation owing to their selective actions on atrial electrophysiology. Herein we report new chemotypes of K(v)1.5 channel blockers that were identified through a combination of structure-based virtual screening and in silico druglike property prediction including six scoring functions, as well as electrophysiological evaluation. Among them, five of the 18 compounds exhibited >50 % blockade ratio at 10 microM, and have structural features different from conventional K(v)1.5 channel blockers. These novel scaffolds could serve as hits for further optimization and SAR studies for the discovery of selective agents to treat AF. |
5,542 | Frequency of sleep apnea in adults with the Marfan syndrome. | Obstructive and central sleep apneas are treatable disorders, which contribute to cardiovascular morbidity in older adults. Younger adults with Marfan syndrome may also be at risk for sleep apnea, but the relation between cardiovascular complications and sleep apnea is unknown. We used MiniScreen8 portable monitoring devices for polygraphy in 68 consecutive adults with Marfan syndrome (33 men, 35 women, 41 +/- 14 years old) to investigate frequency of sleep apnea and its relation to cardiovascular morbidity. The apnea-hypopnea index (AHI) was 6 to 15/hour in 14 subjects (mild sleep apnea, 21%), and AHI was >15/hour in 7 subjects (moderate or severe sleep apnea, 10%). Among established risk factors for sleep apnea, only older age (Spearman rho = 0.35, p = 0.004) and body mass index (rho = 0.26, p = 0.03) were associated with increased AHI. Of all cases of apnea, 12 +/- 27 were obstructive, 11 +/- 25 central, and 3 +/- 9 mixed. AHI was associated with decreased left ventricular ejection fraction (rho = -0.33, p = 0.01), increased N-terminal pro-brain natriuretic peptide levels (rho = 0.35, p = 0.004), enlarged descending aortic diameters (rho = 0.44, p = 0.001), atrial fibrillation (phi = 0.43, p = 0.002), and mitral valve surgery (phi = 0.34, p = 0.02). Of these, left ventricular ejection fraction, N-terminal pro-brain natriuretic peptide levels, atrial fibrillation, and mitral valve surgery were associated with AHI independently of age and body mass index. We found similar associations with oxygen desaturation index. In conclusion, sleep apnea exhibits increased frequency in Marfan syndrome and is not predicted by classic risk factors. Obstructive and central sleep apneas may relate to cardiovascular disease variables. |
5,543 | Outpatient cardiology practices with advanced practice nurses and physician assistants provide similar delivery of recommended therapies (findings from IMPROVE HF). | National guidelines recommend a team model of care to facilitate adherence to evidence-based practices; however, previous studies suggesting benefit may have limited generalizability. The aim of this study was to examine the influence of advanced practice nurse (APN) and physician assistant (PA) staffing on the delivery of guideline-recommended therapies for outpatients with heart failure (HF). The Registry to Improve the Use of Evidence-Based Heart Failure Therapies in the Outpatient Setting (IMPROVE HF), a prospective cohort study, enrolled 167 cardiology practices to characterize outpatient management of 15,381 patients with chronic HF and left ventricular ejection fractions < or =35%. Adherence to guideline-recommended HF therapies was recorded, and the presence of APN and PA staffing was assessed by survey. Multivariate models identified contributions to the delivery of guideline-recommended HF therapies. Of cardiology outpatient practices, 66.0% had APNs and PAs. Practices with 0, >0 to <2, and > or =2.0 APN and PA staffing had similar adherence to the 7 guideline-recommended HF therapies. After adjustment, staffing with > or =2 APNs or PAs was associated with greater conformity with 2 of 7 measures (implantable cardioverter-defibrillator therapy and delivery of HF education, p < or =0.01 for both) and similar conformity to angiotensin-converting enzyme inhibitor or angiotensin receptor blocker therapy, beta-blocker therapy, aldosterone antagonist therapy, anticoagulation for atrial fibrillation, and cardiac resynchronization therapy. In conclusion, staffing with APNs and PAs varied in cardiology outpatient practices. Compared to no APNs or PAs, > or =2.0 APNs or PAs per cardiology practice was associated with the greater use of implantable cardioverter-defibrillator therapy and delivery of HF education and equivalent use of drug and cardiac resynchronization therapies. |
5,544 | Impact of lipid-lowering therapy on outcomes in atrial fibrillation. | Lipid-lowering therapy (LLT) decreases mortality in select patient populations. LLT has also been shown to have antiarrhythmic effects, thus favorably influencing the incidence and recurrence of atrial fibrillation (AF). However, data are lacking regarding the effect of LLT on mortality in patients with AF. The Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) study was the one of the largest multicenter trials comprising of 4,060 patients with AF at high risk for stroke and death. This is a post hoc analysis of the National Heart, Lung, and Blood Institute limited-access dataset of AFFIRM patients who were on LLT at the time of randomization (n = 913). The control group consisted of AFFIRM patients who were not on LLT (n = 3,147). Cox proportional hazards analysis was performed controlling for baseline differences. The end point was all-cause mortality, cardiovascular mortality, and ischemic stroke. A separate analysis was carried out for the combined end point of death, ventricular tachycardia, ventricular fibrillation, cardiac arrest, ischemic stroke, major bleeding, systemic embolism, pulmonary embolism, and myocardial infarction. Patients on LLT were younger and on more cardioactive medications but also had more cardiovascular morbidities. On multivariate analysis, LLT use was associated with lower all-cause mortality (hazard ratio [HR] 0.77, 95% confidence interval [CI] 0.62 to 0.95, p = 0.01), cardiovascular mortality (HR 0.71, 95% CI 0.53 to 0.95, p = 0.02), ischemic stroke (HR 0.56, 95% CI 0.36 to 0.89, p = 0.01), and combined end point (HR 0.81, 95% CI 0.69 to 0.96, p = 0.01). In conclusion, a decrease in mortality and adverse cardiovascular events was observed using LLT in AF. |
5,545 | Percutaneous removal of endocardial implantable cardioverter-defibrillator lead displaced to the right pulmonary artery. | We describe a case of percutaneous removal of endocardial implantable cardioverter-defibrillator lead displaced to the right pulmonary artery. The procedure was performed from two accesses; from the lower one (femoral) and then, due to technical problems, from the upper one (subclavian). In the last stage the flattened Dotter's basket was introduced to the heart inside the Byrd dilator and then fastened to the described lead as the external 'splint'. This solution is an alternative to the recommended use of the internal metal leader with anchoring function in case of significant malformation of the internal lumen of the lead. The procedure we describe is an example of the sort of individual, original solution indispensable for the efficient and safe removal of untypically displaced leads. |
5,546 | Electrocardiographic correlates of microalbuminuria in adult Nigerians with essential hypertension. | Microalbuminuria (MA) is a predictor of excess cardiovascular morbidity and mortality in non-diabetic hypertensive patients. This study evaluated the electrocardiographic correlates of MA in adult non-diabetic Nigerians with essential hypertension. Ninety-six newly diagnosed hypertensive patients who consented and met the inclusion criteria for the study were recruited. Ninety-six age- and gender-matched normotensive controls were also studied. Resting 12-lead electrocardiogram of all patients and controls was done and the tracings analyzed by the authors for left ventricular hypertrophy with or without repolarization abnormalities, QTc prolongation, conduction abnormalities and cardiac arrhythmias such as atrial fibrillation. MA was present in 31 (32.3%) of the hypertensive patients and in only six (6.25%) of the normotensive controls. Electrocardiographic left ventricular hypertrophy (ECG LVH) was significantly more commonly found in patients with MA than in patients without it (74.2% vs 40%, p = 0.002). Left ventricular hypertrophy with ischemic pattern was significantly more frequent in the microalbuminuric hypertensive subset than in non-microalbuminuric patients (32.3% vs 13.8%, p = 0.03). The mean QTc were 0.464 +/- 0.02 s and 0.428 +/- 0.017 s for microalbuminuric and non-microalbuminuric patients respectively (p = 0.01). This study shows that MA is associated with ECG abnormalities such as left ventricular hypertrophy, ischemic pattern ST-T changes and QTc prolongation. This subset of hypertensive patients constitutes a higher risk group and needs intensive monitoring and follow-up. Screening for MA should constitute part of the routine investigation of adult Nigerians with hypertension. |
5,547 | [Safety of magnetic resonance imaging in patients with pacemaker and implantable defibrillator]. | The presence of a cardiac implantable device is ICD considered an absolute contraindication to magnetic resonance imaging (MRI). The purpose of this study was to evaluate the safety of performing MRI in patients with cardiac pacemakers and ICDs that had a compelling clinical need for MRI examination.</AbstractText>During a period of nine years we have included 65 patients with cardiac devices (60 pacemakers and five ICDs) who underwent a total of 73 MRI examinations at 1.5 T. All pacemakers were reprogrammed before MRI to asynchronous mode to avoid MRI-induced inhibition or to sense only mode to avoid MRI-induced competitive pacing and potential pro-arrhythmia. All devices were interrogated immediately before and after the MRI examination, which included measurement of sensitivity, pacing capture threshold (PCT) and lead impedance.</AbstractText>MRI examinations were completed safely in 63 patients. Inhibition of pacemaker output was observed in one patient and induction of ventricular fibrillation was observed in another with ICD. A significant increase in PCT was rare and only detected in 1% of all electrodes.</AbstractText>MRI can be performed safely in patients with pacemakers with an acceptable risk-benefit ratio, while MRI of patients with ICDs must still be considered an experimental procedure.</AbstractText> |
5,548 | [Mistaking a long QT syndrome for epilepsy: does every seizure call for an ECG?]. | Syncope is a common and difficult differential diagnosis for epilepsy. One possible cause for a cardiac syncope is a long QT syndrome (LQTS). LQTS with torsade de pointes tachycardia can lead to lethal ventricular fibrillation and cardiac arrest. Patients with LQTS when first diagnosed as suffering from epileptic fits often experience a particularly long diagnostic delay which may even take years. In some cases, the diagnosis of LQTS is not made until the patient needs resuscitation due to a cardiac arrest. Therefore, ECG recording should be performed for every patient presenting with a seizure considered to be of epileptic origin not only at the beginning of the disease but also when fits occur in spite of antiepileptic treatment in order to prevent an incorrect diagnosis and delay in making the correct diagnosis. |
5,549 | [Pacemaker ECG quiz no. 22. A CRT non-responder with atrial fibrillation]. | A patient with heart failure functional class NYHA III and permanent atrial fibrillation received a system for cardiac resynchronization therapy. Unfortunately, he reports at a follow-up visit about a completely unchanged poor exercise capacity with dyspnea during exercise at a very low level. The ECG reveals an unusual mode of stimulation. |
5,550 | Amiodarone-induced QT prolongation in a newly transplanted heart associated with recurrent ventricular fibrillation. | Anti-arrhythmic drugs such as amiodarone have the potential to prolong QT intervals, which can result in torsades de point arrhythmia. It is unknown whether amiodarone, given to a recipient prior to cardiac transplantation, can cause arrhythmia in a newly transplanted donor heart. We report on a case of a 71-year-old male patient who had received intravenous and oral amiodarone prior to transplantation, which was associated with QT prolongation in the transplanted heart after re-exposure to the drug during subsequent episodes of ventricular fibrillation. An ICD was implanted, which has not been described that soon after cardiac transplantation. Amiodarone, given to a recipient, might cause QT prolongation in a donor heart after transplantation, possibly due to its long half-life and increased bioavailability caused by interaction with immunosuppressive drugs. |
5,551 | Catheter ablation for paroxysmal atrial fibrillation: a randomized comparison between multielectrode catheter and point-by-point ablation. | Catheter ablation for paroxysmal atrial fibrillation is widely used for patients with drug-refractory paroxysms of arrhythmia. Recently, novel technologies have been introduced to the market that aim to simplify and shorten the procedure.</AbstractText> To compare the clinical outcome of pulmonary vein (PV) isolation using a multipolar circular ablation catheter (PVAC group), with point-by-point PV isolation using an irrigated-tip ablation catheter and the CARTO mapping system (CARTO group; CARTO, Biosense Webster, Diamond Bar, CA, USA).</AbstractText> Patients with documented PAF were randomized to undergo PV isolation using PVAC or CARTO. Atrial fibrillation (AF) recurrences were documented by serial 7-day Holter monitoring.</AbstractText>One hundred and two patients (mean age 58 ± 11 years, 68 men) were included in the study. The patients had comparable baseline clinical characteristics, including left atrial dimensions and left ventricular ejection fraction, in both study arms (PVAC: n = 51 and CARTO: n = 51). Total procedural and fluoroscopic times were significantly shorter in the PVAC group (107 ± 31 minutes vs 208 ± 46 minutes, P < 0.0001 and 16 ± 5 minutes vs 28 ± 8 minutes, P < 0.0001, respectively). The AF recurrence was documented in 23% and 29% of patients in the PVAC and CARTO groups, respectively (P = 0.8), during the mean follow-up of 200 ± 13 days. No serious complications were noted in both study groups.</AbstractText>Clinical success rates of PV isolation are similar when using multipolar circular PV ablation catheter and point-by-point ablation with a three-dimensional (3D) navigation system in patients with PAF, and results in shorter procedural and fluoroscopic times with a comparable safety profile.</AbstractText>©2010, The Authors. Journal compilation ©2010 Wiley Periodicals, Inc.</CopyrightInformation> |
5,552 | Statins and the reduction of sudden cardiac death: antiarrhythmic or anti-ischemic effect? | Sudden cardiac death is an important cause of cardiovascular mortality with the majority of cases occurring in low-risk groups. HMG-CoA reductase inhibitors (statins) have recently been shown to reduce the incidence of ventricular tachycardia (VT)/fibrillation (VF) and sudden cardiac death, and this has been attributed to their pleiotropic effects. However, it is unclear whether this occurs through an 'indirect' anti-ischemic or 'direct' antiarrhythmic effect. We systematically reviewed articles published on MEDLINE between January 1996 and December 2009 focusing on the reduction of VT/VF and sudden cardiac death by statins and the potential mechanisms. Studies reporting sudden cardiac death or VT/VF outcomes with statin use (n = 23) or the pathophysiology of sudden cardiac death reduction by statins (n = 19) were included. We found that statins have been shown to reduce VT/VF and sudden cardiac death only in subjects with underlying coronary artery disease or ischemic cardiomyopathy. No definite benefits were seen with statins in sudden cardiac death and VT/VF in patients with non-ischemic cardiomyopathy. There is insufficient evidence to point toward a benefit in populations at low risk for VT/VF. In conclusion, an anti-ischemic rather than a primary antiarrhythmic effect emerges as the likely mechanism of sudden cardiac death reduction with statins. |
5,553 | Heart rate and systolic blood pressure in patients with persistent atrial fibrillation. A linguistic analysis. | During atrial fibrillation (AF), ventricular response is highly irregular and thus the beat-to-beat variation of blood pressure is increased because of variations in filling time and in contractility.</AbstractText>Aim of the present study is to investigate the short-term dynamics of RR and SAP series in patients with AF, during rest and tilt, and after restoration of sinus rhythm.</AbstractText>We computed symbolic sequences of the three phases, as they retain important features of the dynamics generated by the underlying control system. Then we applied a method based on rank order statistics of symbolic sequences to investigate the profile of different types of dynamics. The linguistic distance (range 0-1) between sequences represents a measure of similarity to assess whether the different physiological states are reflected on the dynamics of RR and SAP series.</AbstractText>The distance between rest and tilt phases is 0.06 ± 0.02 for RR series, meaning they are very similar, while it is 0.21 ± 0.13 for SAP series, showing a difference in the short-term dynamics. RR mean decreases during tilt (738 ± 164 vs. 692 ± 152 ms, p <0.05, rest vs. tilt), while mean SAP is not significantly different (101 ± 20 vs. 104 ± 14 mmHg, rest vs. tilt). Comparing AF and sinus rhythm, both RR and SAP series result different in terms of the computed distance.</AbstractText>SAP short-term dynamics seem to significantly change when comparing rest and tilt phases, while RR series remain unchanged. Moreover, RR mean but not SAP series significantly decreases during tilt.</AbstractText> |
5,554 | Implantable cardioverter-defibrillator shock: appropriate or inappropriate? | A 76-year-old female with a single chamber implantable cardioverter-defibrillator implanted for secondary prevention was referred due to multiple discharges. The device was programmed for ventricular tachycardia (VT) detection at 400 ms, fast VT detection at 280 ms, and ventricular fibrillation detection at 320 ms. Antitachycardia pacing (ATP) during charge was enabled. Interrogation revealed a VT episode with a mean cycle length of 270 ms, which was successfully terminated with ATP during charge. Seconds later, the device delivered a shock. This case illustrates the importance of understanding programming algorithms as part of troubleshooting when facing a scenario of device discharge. |
5,555 | Fragmented QRS in prediction of cardiac deaths and heart failure hospitalizations after myocardial infarction. | Increased QRS fragmentation in visual inspection of 12-lead ECG has shown association with cardiac events in postmyocardial infarction (MI) patients. We investigated user-independent computerized intra-QRS fragmentation analysis in prediction of cardiac deaths and heart failure (HF) hospitalizations after MI.</AbstractText>Patients (n = 158) with recent MI and reduced left ventricular ejection fraction (LVEF) were studied. A 120-lead body surface potential mapping was performed at hospital discharge. Intra-QRS fragmentation was computed as the number of extrema (fragmentation index FI) in QRS. QRS duration (QRSd) was computed for comparison.</AbstractText>During a mean follow-up of 50 months 15 patients suffered cardiac death and 23 were hospitalized for HF. Using the mean + 1 SD as cut-point both parameters were univariate predictors of both end-points. In multivariate analysis including age, gender, LVEF, previous MI, bundle branch block, atrial fibrillation, and diabetes FI was an independent predictor for cardiac deaths (HR 8.7, CI 3.0-25.6) and HF hospitalizations (HR 3.8, CI 1.6-9.3) whereas QRSd only predicted HF hospitalizations (HR 4.6, CI 2.0-10.7). In comparison to QRSd, FI showed better positive (PPA) and equal negative (NPA) predictive accuracy for both end-points, and PPA was further improved when combined to LVEF < 40%. Limiting fragmentation analysis to 12-lead ECG or a randomly selected 8-lead set instead of all 120 leads resulted in an almost similar prediction.</AbstractText>Increased QRS fragmentation in post-MI patients predicts cardiac deaths and HF progression. A computer-based fragmentation analysis is a stronger predictor than QRSd.</AbstractText> |
5,556 | [Is intraoperative ICD-testing still necessary?]. | Intraoperative ICD-testing is traditionally performed in many hospitals in order to ensure reliable sensing, detection, and defibrillation of induced ventricular fibrillation. The technical progress of defibrillators allows rapid detection and delivery of high energy shocks which defibrillates effectively in the vast majority all patients at implant. This review describes arguments pro and contra of systematic testing of the defibrillation threshold in all patients. Many reasons argue against testing in all patients: experimental considerations, patients' specific and nonspecific factors, e.g., underlying severity of cardiac disease, ischemia, and medication, as well as factors specific to the ICD system, e.g., implanted type and location of electrodes and active cans. Finally, the testing method is very important, since it bears the risk of false negative test results because the a priori probability of a positive test result is >95%. Therefore, data from prospective randomized studies are necessary in order to abandon the tradition of ICD-testing on an evidence-based background. |
5,557 | ALLHAT: still providing correct answers after 7 years. | The Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) is re-evaluated considering information from recent subgroup and exploratory analyses, other new clinical trials, and meta-analyses. The ALLHAT analyses specifically emphasize heart failure findings, results in Black participants and those with chronic kidney disease, selection and doses of thiazide and similar diuretics, and the association of antihypertensive drug use with new-onset diabetes and its cardiovascular consequences.</AbstractText>The initial ALLHAT conclusion, that thiazide diuretics are superior to angiotensin-converting enzyme inhibitors (ACEIs), calcium antagonists (CCBs) and alpha-blockers in preventing one or more major clinical outcomes, including heart failure and stroke, and unsurpassed in significantly preventing any cardiovascular or renal outcome, has been further validated for patients with diabetes, renal disease, and/or metabolic syndrome. The evidence is even more compelling for Black patients. New-onset diabetes associated with thiazides did not increase cardiovascular outcomes. The diuretic was superior to all in preventing heart failure with preserved left-ventricular ejection fraction (LVEF) and similar to the ACEI in preventing heart failure with impaired LVEF. It was also unsurpassed in preventing atrial fibrillation.</AbstractText>The totality of evidence re-affirms the initial ALLHAT conclusion that thiazide and similar diuretics (at evidence-based doses) are the preferred first-step therapy in most patients with hypertension.</AbstractText> |
5,558 | Association of plasma B-type natriuretic peptide levels with obesity in a general urban Japanese population: the Suita Study. | The inverse association between plasma B-type natriuretic peptide (BNP) levels and body mass index (BMI) has been reported in Western populations. Here we analyzed the relationship between plasma BNP and obesity in a general urban Japanese population. We recruited 1,759 subjects without atrial fibrillation or history of ischemic heart disease aged 38-95 years (mean age +/- standard deviation 64.5 +/- 10.9 years, 56.1% women, mean BMI 22.8 +/- 3.1 kg/m(2)) from the participants in the Suita Study between August 2002 and December 2003. In multivariable regression analyses adjusted for age, systolic blood pressure, pulse rate, serum creatinine, left ventricular hypertrophy in ECG, the inverse relationships between BNP levels and BMI (kg/m(2)) was found in both sexes (both p<0.001). Multivariable-adjusted mean plasma BNP levels in the group of BMI<18.5, 18.5< or =BMI< 22, 22< or =BMI<25, and 25< or =BMI were 23.4, 17.9, 14.0 and 13.0 pg/mL, respectively (trend p<0.001). The negative association of body fat (percentage and mass), skin fold thickness, or waist circumference with BNP levels was observed the negative associations in both sexes (p<0.01). Among the obesity indices, body fat mass is most tightly associated with BNP. In conclusion, plasma BNP was inversely associated with obesity related markers such as body fat mass, skinfold thickness and waist circumferences after adjusted for relevant covariates in a Japanese population. |
5,559 | Ventricular fibrillation in a man shot with a Taser. | Controversy exists concerning the lethality of Tasers. These are conducted electrical weapons which incapacitate subjects by delivering an electrical charge that causes diffuse muscle contraction. In North America, over 440 deaths have been reported immediately following Taser use. Taser International has recently suggested that Tasers should not be aimed at the chest, although there is no conclusive proof that a discharge over the heart would cause an arrhythmia. The case history is presented of a young man who was shot in the chest by a Taser and presented to the emergency department in ventricular fibrillation. |
5,560 | Uric acid elevation in atrial fibrillation. | Uric acid is a cardiovascular risk marker associated with oxidative stress and inflammation. Recently, atrial fibrillation (AF) has been associated with inflammation and oxidative stress. We therefore investigated the association between AF and uric acid levels.</AbstractText>Consecutive patients with AF and healthy control subjects were screened. Demographic, clinical, and echocardiographic characteristics were carefully recorded. In each participant, uric acid levels and conventional inflammatory markers were determined. The final study population consisted of 45 patients with paroxysmal AF, 41 patients with permanent AF, and 48 control subjects.</AbstractText>A significant variance in uric acid levels was evident between patients with paroxysmal AF (5.7 +/- 1.1 mg/dl), permanent AF (6.7 +/- 1.4 mg/dl), and control subjects (5.1 +/- 1.3 mg/dl) (p<0.001). After univariate analysis considering 2 groups (control, AF patients), the following variables were significantly associated with the presence of AF: age, hypertension, -blocker use, low left ventricular ejection fraction (LVEF), increased left atrial diameter, uric acid levels, and C-reactive protein (CRP) levels. After multivariate logistic regression analysis, only CRP was an independent predictor for AF (odds ratio, OR: 2.172). In a subgroup analysis, CRP (OR: 1.434) and LVEF (OR: 0.361) were independent predictors of paroxysmal AF, while CRP (OR: 3.048), uric acid (OR: 2.172), and LVEF (OR: 0.34) were predictors of permanent AF.</AbstractText>There is an association between increased levels of uric acid and permanent AF. Also, uric acid elevation may be related to the burden of AF. Undoubtedly, larger studies should further examine this potential association.</AbstractText> |
5,561 | Hospitalized lithium overdose cases reported to the California Poison Control System. | Lithium overdose primarily results in neurologic toxicity; however, cardiac effects have also been reported. Our aim was to describe a large cohort of hospitalized lithium overdose patients. Specifically we were interested in reported cardiac complications, frequency of hemodialysis (HD), and mortality.</AbstractText>This is a retrospective, observational case series of admitted isolated lithium exposure cases reported to the California Poison Control System (CPCS) from 2003 through 2007. Reported lithium exposure cases were identified by a search of our CPCS database. Only those cases resulting in hospital admission were included in this study. Cases with concomitant toxic exposures were excluded. Primary outcome variables were reported cardiac complications (defined as bradycardia with a heart rate < or =50 bpm, atrioventricular (AV) block, ventricular tachycardia, and ventricular fibrillation), administration of cardiovascular intervention (resuscitation, vasopressor medications, or cardiac pacing), and death.</AbstractText>In the 5-year-study period 629 lithium cases were reported to the CPCS and 502 hospitalized cases were included in this study. There were 44 [8.8%; 95% confidence intervals (CI) 6.3, 11.2] cases of acute lithium exposure, 124 (24.7%; 95% CI 20.9, 28.5) cases of acute on chronic (AC) overdose, and 282 (56.2%; 95% CI 51.8, 60.5) cases of chronic overdose. Sixty-nine patients received hemodialysis. This includes 6 (13.6%) acute, 12 (9.7%) AC, and 45 (16.0%) chronic cases. There were four deaths (0.8%, 95% CI 0.2, 1.6). Cardiac complications were reported in 29 cases (5.7%, 95% CI 3.7, 7.7%) with 18 of these cases (18/29; 62%) being isolated bradycardias (without hypotension). Only seven patients with reported cardiac complication (7/29; 24.1%; 95% CI = 8.6, 39.7) required cardiovascular intervention and all of these were cases of chronic lithium toxicity. Two bradycardic arrests occurred in chronic lithium exposure cases, including one who died.</AbstractText>In this cohort of hospitalized lithium exposure patients, death was rare. Reported cardiac complications were unusual with instances requiring cardiovascular intervention occurring only in cases of chronic lithium overdose. The majority of lithium toxicity cases were managed without HD.</AbstractText> |
5,562 | [Risk stratification in non ischemic cardiomyopathy: a case report--Case 5/2010]. | A 65-year-old male patient with rapid increasing shortness of breath and newly diagnosed atrial fibrillation was admitted to our hospital.</AbstractText>The ECG revealed atrial fibrillation. Echocardiography showed severe decreased left ventricular function. The magnetic resonance imaging (MRI) scan confirmed the severe reduced left ventricular function with a two graded mitral regurgitation as well as a pronounced late enhancement in the posterobasal area of the interventricular septum. Cardiac catheterisation showed mild diffuse atherosclerosis of the coronary arteries without stenotic lesions. Multiple myocardial biopsies of the right ventricle revealed extensive remodelling processes with focal fibrosis in presence of mononuclear cell infiltrates, T-wave alternans and the heart rate variability were positive.</AbstractText><AbstractText Label="DIAGNOSIS, TREATMENT AND COURSE" NlmCategory="METHODS">Nonischaemic cardiomyopathy (NICM) with severe reduced left ventriucular function was diagnosed. After successful electrical cardioversion and initiation of a sufficient heart failure treatment, the clinical symptoms as well as left ventricular function improved significantly.</AbstractText>Risk stratification of sudden cardiac death remains a clinical challenge especially in NICM. Significantly predictors in ischaemic cardiomyopathy, such as heart rate turbulance (HRT) and T-wave alternans, are not useful or have no importance in NICM. However, the prognosis does not correlate with restricted left ventricular function in NICM. Cardiac MRI or marker of autonomic dysfunction could be helpful in risk stratification. How far late enhancement is a surrogate parameter or the real substrate for life threatening arrhythmias is still unclear. Non-invasive risk stratification could be helpful in borderline decisions, however, it should not be taken mandatory. Close-meshed control intervals of the clinical status under optimal medication are recommended, followed by a implantation of an implantable cardioverter-defibrillator (ICD) if needed. ICD implantation is superior to medical treatment in persistent depressed left ventricular function. The ideal time for ICD implantation in newly diagnosed NICM remains unclear at the moment.</AbstractText>Georg Thieme Verlag KG Stuttgart New York.</CopyrightInformation> |
5,563 | Coexisting sustained tachyarrthymia in patients with atrial fibrillation undergoing catheter ablation. | During the index procedure of catheter ablation (CA) for atrial fibrillation (AF), it is important to assess whether other atrial or ventricular tachyarrhythmia coexist. Their symptoms are often attributed to residual tachycardia after successful elimination of AF by CA. This tachycardia could also be non-pulmonary vein (PV) foci initiated AF. This study examined the coexistence of other sustained tachyarrhythmia of patients who underwent radiofrequency CA (RFCA) for AF.</AbstractText>Four hundred fifty-nine consecutive patients (375 males, aged 53.4+/-11.4 years) who underwent RFCA for AF were investigated. Atrial and ventricular programmed stimulation (PS) with or without isoproterenol infusion were performed, and spontaneously developed tachycardias were analyzed.</AbstractText>Fifteen patients (3.3% of total) were diagnosed to have other sustained arrhythmias that included slow-fast type atrioventricular nodal reentrant tachycardia (AVNRT, n=6), atrioventricular reentrant tachycardia (AVRT, n=5) that utilized left posteroseptal (n=4) and parahisian bypass tract (n=1), atrial tachycardia (AT, n=2) originating from the foramen ovale (n=1) and the ostium of coronary sinus (n=1), sustained ventricular tachycardia (VT, n=2) involving one from the apical posterolateral wall of left ventricule in a normal heart and one from an anterolateral wall in an underlying myocardial infarction (MI). These sustained tachycardias were neither clinically documented nor had structural heart diseases, with the exception of one patient with MI associated VT. Two patients had the triple tachycardia; one involved AVNRT, AVRT, and AF, and the other involved VT, AT, and AF. All associated tachycardias were successfully eliminated by RFCA.</AbstractText>Fifteen (3.3%) patients with AF had coexisting sustained tachycardia. RFCA was successful in these patients. Identification of tachycardia by PS before RFCA for AF should be done to maximize the efficacy of the first ablation session.</AbstractText> |
5,564 | Clinicopathological profiles of progressive heart failure in hypertrophic cardiomyopathy. | Hypertrophic cardiomyopathy (HCM) is an important cause of heart failure-related disability over a wide range of ages. Profiles of severe progressive heart failure symptoms and death, or heart transplantation deserve more complete definition within large patient cohorts.</AbstractText>Clinical and morphological features of heart failure were assessed in 293 consecutive HCM patients over a median follow-up of 6 (inter-quartile range 2-11) years. Gross and histopathological features were analysed in 12 patients for whom the heart was available for inspection. Of the 293 patients, 50 (17%) developed severe progressive heart failure, including 18 who died or were transplanted. Three profiles of heart failure were identified predominantly associated with: (i) end-stage systolic dysfunction (ejection fraction <50%) (15; 30%); (ii) left ventricular (LV) outflow obstruction at rest (11; 22%); and (iii) non-obstructive with preserved systolic function (24; 48%). Overall, atrial fibrillation (AF) contributed to heart failure in 32 patients (64%) among the three profiles. Compared with other patients, those non-obstructive with preserved systolic function had earlier onset of heart failure symptoms mainly due to diastolic dysfunction, and the most accelerated progression to advanced heart failure and adverse outcome (P = 0.04). Thrombi were identified in the left atrial appendage of five gross heart specimens all belonging to patients with AF, including three of which were unrecognized clinically and had previously embolized. Extensive myocardial scarring with LV remodelling was evident in all end-stage patients; no or only focal scars were present in other patients.</AbstractText>Profiles of advanced heart failure in HCM are due to diverse pathophysiological mechanisms, including LV outflow obstruction and diastolic or global systolic ventricular dysfunction. Atrial fibrillation proved to be the most common disease variable associated with progressive heart failure. Recognition of the heterogeneous pathophysiology of heart failure in HCM is relevant, given the targeted management strategies necessary in this disease.</AbstractText> |
5,565 | The Utility of Ambulatory Electrocardiographic Monitoring for Detecting Silent Arrhythmias and Clarifying Symptom Mechanism in an Urban Elderly Population with Heart Failure and Hypertension: Clinical Implications. | <b>Background:</b> Atrial and ventriclar tachyarrhythmias, as well as bradyarrhythmias, in the elderly with heart failure (HF) and/or hypertension (HTN) have been well documented. However, the frequency of these arrhythmias, whether silent or symptomatic, and their association with subsequent cardiac events has not been well defi ned in patients 65 years or older with HF and other cardiovascular risk factors. <b>Objective:</b> To assess the value of 2 weeks of remote, transtelephonic cardiac monitoring for detecting arrhythmias in an elderly, urban population living with HF. <b>Methods:</b> Fi" y-four patients with a history of systolic HF and/or HTN were consented and enrolled. All wore an auto triggered cardiac loop monitor for 2 weeks that captures EKG data and both silent and symptomatic arrhythmias were recorded. <b>Results:</b> Mean age was 73 ± 6 years with 59% of subjects were females, 74% Hispanic, 22% black, and 4% white/other. All patients had HF and 94% had HTN. From the cardiac monitoring, 72% demonstrated ectopic atrial and ventricular activity, and 1 paroxysmal episode of atrial fi brillation was documented. In addition, 3 subjects had signifi cant non-sustained ventricular tachycardia, and 4 individuals had severe bradycardia recorded on cardiac monitoring. These 7 individuals underwent placement of an implantable cardioverter defi brillator (ICD) or pacemaker based on the documented arrhythmias which may have otherwise gone undetected. <b>Conclusions:</b> A substantial proportion of patients exhibited cardiac arrhythmias. Future morbidity was prevented because of the detection of arrhythmias on monitoring that led to specifi c therapies such as pacemaker or ICD implantation which otherwise may not have been implemented. |
5,566 | Antiarrhythmic and nonantiarrhythmic drugs for sudden cardiac death prevention. | Life-threatening ventricular arrhythmias such as sustained ventricular tachycardia and ventricular fibrillation are responsible for two thirds of sudden cardiac deaths annually in the United States. Implantable cardioverter-defibrillator (ICD) therapy prevents mortality from arrhythmic death but is expensive and has some associated morbidity from proarrhythmia and mechanical malfunction. Furthermore, ICDs treat ventricular arrhythmias but do not prevent them. Antiarrhythmic drugs (AADs) can be used for acute or chronic therapy to prevent ventricular arrhythmias and sudden cardiac deaths. AADS are often used in patients with an ICD who have recurrent ICD shocks resulting from ventricular arrhythmias. Class I AADs are contraindicated in patients with structural heart disease. Other than amiodarone, all Class III drugs have either a neutral or deleterious effect on mortality. Dronedarone, a new Class III drug, may reduce mortality, but more information is needed to be sure. A class of drugs that do not qualify as an AAD can modify cardiovascular remodeling processes and have a delayed and indirect antiarrhythmic effect. These so-called "nonantiarrhythmic drugs" such as drugs acting on the renin-angiotensin-aldosterone system, fish oil, and statins can reduce the likelihood of future ventricular tachycardia/ventricular fibrillation in patients with coronary artery disease or congestive heart failure. The role of AADs for chronic therapy for primary and secondary prevention of sudden cardiac death is problematic because of proarrhythmia and adverse side effects. Because these nonantiarrhythmic drugs are well tolerated and have no proarrhythmic actions, their benefits should outweigh risks. |
5,567 | Diagnostic performance of a new multifunctional electrocardiograph during uninterrupted chest compressions in cardiac arrest patients. | External chest compression is considered to play a significant role in cardiopulmonary resuscitation (CPR), but during a rhythm check, chest compressions must be discontinued to avoid artifacts. A new multifunctional electrocardiograph (ECG; Radarcirc) has been developed for use in clinical settings.</AbstractText>The performance of the Radarcirc and conventional ECG (CoECG) during CPR was compared in a single-center, non-randomized, sequential self-controlled study. CPR was performed on 41 out-of-hospital cardiac arrest patients. Cardiac rhythm with and without chest compressions during a rhythm check was measured using leads I and II. When the rhythm changed during CPR, it was measured as another waveform. Fifty ECG recordings were obtained, of which 27 were asystole, 18 pulseless electrical activity, and 5 ventricular fibrillation (VF). The area under the receiver-operating characteristic curve (AUC) for VF was 0.448 (95% confidence interval (CI) 0.274-0.622) for lead II of the CoECG, and 0.797 (95%CI 0.684-0.910) for lead II of the Radarcirc. The AUC for VF was 0.422 (95%CI 0.219-0.626) for lead I of the CoECG, and 0.987 (95%CI 0.975-1.00) for lead I of the Radarcirc.</AbstractText>Diagnoses based on the data from Radarcirc were more accurate in predicting rhythm during chest compressions than those based on data from the CoECG.</AbstractText> |
5,568 | Effects of angiotensin receptor blockade on atrial electrical remodelling and the 'second factor' in a goat burst-paced model of atrial fibrillation. | Atrial fibrillation (AF) is self-perpetuating, via mechanisms of acute electrical remodelling and 'second factors' acting over a longer time course. Renin-angiotensin system (RAS) blockade may inhibit AF self-perpetuation. We evaluated the effects of RAS blockade with candesartan in a burst-paced goat model of lone AF in which both mechanisms are known to operate. Bioactivity of oral candesartan was demonstrated in 10 goats by inhibition of the pressor effect of angiotensin II. The effects of candesartan on electrical remodelling were assessed in 12 placebo and 12 candesartan-treated goats in a 28-day burst pacing protocol. To assess the effects of candesartan on second factors (structural remodelling), 16 goats underwent further 28-day periods of burst pacing (two periods in 16 goats, three periods in eight goats) each separated by periods of sinus rhythm sufficient for electrical remodelling to reverse. There was a progressive rise in angiotensin levels in both groups. Candesartan (0.5 mg/kg/day) achieved a 76% blunting of the pressor effect of angiotensin II and had no effect on electrical remodelling; the half time for fall of atrial effective refractory period (AERP) was 22.3 ± 4.9 h (placebo) and 22.0 ± 3.2 h (candesartan) (p = ns). Candesartan had no effect on AF stability, which progressively increased over successive 28-day periods (ANOVA p < 0.05). Candesartan had no effect on atrial electrical remodelling or the operation of 'second factors' in a goat model of lone AF. These findings suggest that any benefits of RAS blockade in patients with AF are unlikely to be due to direct effects on atrial remodelling. |
5,569 | [Remote control in ICD therapy]. | In several studies, ICD therapy has been shown to be an effective treatment option for patients suffering from or being at risk of malignant ventricular arrhythmias. Given the increasing rate of ICD implantations with the need for in-office interrogations at least twice a year, the number of follow-up visits is constantly growing. Remote transmission of relevant ICD data is a way to reduce follow-up burden for the physician, travel costs for the patient, and the time delay between onset of medical or device problems and an adequate physician response. In several studies, it has been demonstrated that remote ICD follow-up is safe and reduces follow-up resources for both the patient and the physician. With ongoing studies, the questions of whether remote ICD interrogations can offer additional diagnostic and therapeutic options that go beyond pure device follow-up and allow for a more complex management of ICD patients, who in fact represent a large percentage of the heart failure population, will have to be answered. |
5,570 | Reduction in the intensity rate of appropriate shocks for ventricular arrhythmias with statin therapy. | Higher rate of implantable cardioverter-defibrillator (ICD) shocks has been associated with increased mortality and morbidity. The aim of our study was to determine whether statins reduced the intensity rate of appropriate shock therapy for ventricular tachycardia/fibrillation in patients with an ICD placed for left ventricular systolic dysfunction. In this retrospective single center analysis, patients with an ejection fraction <or=35% who underwent ICD implantation were divided into treatment and control groups based on statin use. A zero-inflated negative binomial model was used to compare the intensity rate of appropriate ICD shocks between the 2 groups. Characteristics associated with shock-free follow-up were assessed using a stepwise logistic regression model. We found 699 patients eligible for inclusion, with 412 (59%) in the statin treatment group. The adjusted mean intensity rate of shocks was lower in patients on statin therapy (intensity rate ratio = 0.22; 95% confidence interval, 0.12-0.41; P < 0.001). Statin use was associated with a significantly higher probability of shock-free follow-up (odds ratio = 1.64; 95% confidence interval, 1.09-2.48; P = 0.019). In conclusion, statins reduced the intensity rate of appropriate shock therapy for ventricular tachycardia/fibrillation and increased probability of shock-free follow-up in patients with cardiomyopathy. Larger randomized trials are needed to confirm this relationship. |
5,571 | [Implantable cardioverter-defibrillator oversensing due to electric shock]. | We described the first case of oversensing due to electric shock in Serbia, in a 54-year-old man who had implantable cardioverter-defibrillator (ICD).</AbstractText>In July 2002, the patient had acute anteroseptal myocardial infarction and ventricular fibrillation (VF) which was terminated with six defibrillation shocks of 360 J. Coronary angiography revealed 30% stenosis of circumflex artery, the left anterior descending coronary artery was recanalized and the right coronary artery was without stenosis. Left ventricular ejection fraction was 20%. In December 2003, an electrophysiology study was performed and ventricular tachycardia (VT) was induced and terminated with 200 J defibrillation shock. Single chamber ICD Medtronic Gem III VR was implanted in January 2004 and defibrillation threshold was 12 J. The patient was followed up during three years every three months and there were no VT/VF episodes and VT/VF therapies. In December 2007, the patient experienced electric shock through the fork while he was making barbecue on the electric grill. ICD recognized this event in VF zone (oversensing) and delivered defibrillation shock of 18 J. The electrogram of the episode showed ventricular sensing--intrinsic sinus rhythm with electric shock potentials which were misidentified as VF. After charge time of 3.16 seconds, ICD delivered defibrillation shock and sinus rhythm was still present.</AbstractText>Oversensing of ICD has different aetiology and the most common cause is supraventricular tachyarrhythmia.</AbstractText> |
5,572 | [Relationship between mortality of patients with atrial fibrillation and mortality of general population in Serbia]. | Large population-based observational trials have shown atrial fibrillation (AF) to be an independent risk factor for increased mortality.</AbstractText>To examine all-cause mortality and cardiovascular mortality of patients with AF compared to corresponding mortality in general population of Serbia.</AbstractText>This longitudinal observational study included patients with nonvalvular AF as the main indication for in-hospital and/or outpatient treatment at the Clinical Centre of Serbia, Belgrade, during the period 1992-2007, if the latest date of the first diagnosed AF was early January 2003, so that the total follow-up could last at least 5 years (minimum 1 year prospectively), or until death. Patients with acute causes of AF, advanced left ventricular systolic dysfunction (LVEF < or = 25%), preexcitation, known malignancy or any advanced chronic disease and patients with poorly documented history of previous AF were not included. To compare mortality of study population with mortality of general population, we used standardized mortality ratio (SMR) and chi-square test, p < 0.05.</AbstractText>Out of 1100 patients (389 females, 35.4%), aged 52.7 +/- 12.2 years, with total follow-up 9.94 +/- 6.05 years (prospective 5.75 +/- 4.28, retrospective 4.21 +/- 5.51), 40% had no underlying disease; others most frequently had arterial hypertension. AF was paroxysmal in 665 (60.5%), persistent in 225 (20.5%) and permanent in 210 patients (19.1%). Newly diagnosed AF was documented in 1058 patients (96.2%). Until the end of the study, 85 patients died (7.7%). Cardiovascular death was noted in 62 patients (72.9%), most frequently in form of sudden death (27/85, 31.7%), death from congestive heart failure (18/85, 21.2%) and stroke (14/85, 16.5%). Most patients (67/85, 78.8%) had AF at the time of death. SMR for all-cause mortality was 2.43 (p < 0.0001) and for cardiovascular mortality 3.03 (p < 0.0001).</AbstractText>All-cause mortality and cardiovascular mortality of AF patients are higher than corresponding mortality in general population of Serbia, despite active treatment.</AbstractText> |
5,573 | Ventricular fibrillation due to coronary spasm at the site of myocardial bridge -A case report-. | Myocardial bridge is a congenital anomaly characterized by narrowing of some of the epicardial coronary arterial segments running in the myocardium during systole. Occasionally, the compression of a coronary artery by a myocardial bridge can be associated with the clinical manifestations of myocardial ischemia, and might even trigger a myocardial infarction or malignant ventricular arrhythmias. We report a case of ventricular fibrillation due to coronary spasm at the site of myocardial bridge. A 56-year-old man who had suffered from bronchial asthma was given remifentanil combined with sevoflurane in general anesthesia for endoscopic sinus surgery. During the surgery, ventricular fibrillation occurred following coronary spasm with bradycardia, hypotension, bronchospasm. we found myocardial bridge that coincided with an area of coronary spasm after coronary angiography. |
5,574 | Beta-blockers for chest pain associated with recent cocaine use. | Although beta-blockers prevent adverse events after myocardial infarction, they are contraindicated when chest pain is associated with recent cocaine use. Recommendations against this use of beta-blockers are based on animal studies, small human experiments, and anecdote. We sought to test the hypothesis that beta-blockers are safe in this setting.</AbstractText>We performed a retrospective cohort study of consecutive patients admitted to the San Francisco General Hospital, San Francisco, California, with chest pain and urine toxicologic test results positive for cocaine, from January 2001 to December 2006. Mortality data were collected from the National Death Index.</AbstractText>Of 331 patients with chest pain in the setting of recent cocaine use, 151 (46%) received a beta-blocker in the emergency department. There were no meaningful differences in electrocardiographic changes, troponin levels, length of stay, use of vasopressor agents, intubation, ventricular tachycardia or ventricular fibrillation, or death between those who did and did not receive a beta-blocker. After adjusting for potential confounders, systolic blood pressure significantly decreased a mean 8.6 mm Hg (95% confidence interval, 14.7-2.5 mm Hg) in those receiving a beta-blocker in the emergency department compared with those who received their first beta-blocker in the hospital ward (P = .006). Over a median follow-up of 972 days (interquartile range, 555-1490 days), after adjusting for potential confounders, patients discharged on a beta-blocker regimen exhibited a significant reduction in cardiovascular death (hazard ratio, 0.29; 95% confidence interval, 0.09-0.98) (P = .047).</AbstractText>beta-Blockers do not appear to be associated with adverse events in patients with chest pain with recent cocaine use.</AbstractText> |
5,575 | Clinical trials update from the American College of Cardiology meeting 2010: DOSE, ASPIRE, CONNECT, STICH, STOP-AF, CABANA, RACE II, EVEREST II, ACCORD, and NAVIGATOR. | This article provides information and a commentary on trials relevant to the pathophysiology, prevention and treatment of heart failure presented at the annual meeting of the American College of Cardiology held in March 2010. Unpublished reports should be considered as preliminary, since analyses may change in the final publication. Results from DOSE suggest that giving diuretics using a high-dose, bolus strategy may be better than using lower doses or a continuous infusion for patients with acute decompensated heart failure. In the ASPIRE study, addition of aliskiren to standard therapy failed to attenuate left ventricular remodelling in post-MI patients and was associated with more adverse events. In CONNECT, remote monitoring reduced the time from CRT-D- or ICD-detected events to clinical decision and this was associated with fewer clinic visits and shorter hospitalizations. An analysis from STICH testing the effects of surgical ventricular reconstruction showed no benefit in the sub-group of patients who achieved a greater reduction in LV volume. STOP-AF and CABANA did not provide convincing evidence of the effectiveness or safety of catheter ablation for the treatment of AF. RACE II suggests that lenient heart rate control might be as effective as strict rate control in patients with permanent atrial fibrillation. In EVEREST II, a catheter-based mitral valve repair procedure using the MitraClip system had similar efficacy to traditional surgery but with fewer short-term adverse effects. Valsartan reduced progression to diabetes in patients with impaired glucose tolerance but had no effect on cardiovascular events in NAVIGATOR. In ACCORD, strict blood pressure control failed to reduce the risk of overall cardiovascular events in high-risk diabetic patients. |
5,576 | Primary prevention of sudden cardiac death by implantable cardioverter-defibrillator therapy in Chinese patients with heart failure: a single-center experience. | An implantable cardioverter-defibrillator (ICD) has been suggested for heart failure patients for primary prevention of sudden cardiac death. However, few data have been reported on the application of ICD as primary prevention of sudden cardiac death in China. We evaluated the value of primary prevention ICD therapy in Chinese patients with heart failure.</AbstractText>Thirty-four patients at an average age of (60.2 +/- 13.7) years seen in Peking Union Medical College Hospital were treated with ICD implantation for primary prevention of sudden cardiac death from November 2005 to July 2009. Single-chamber ICDs were implanted in 16 (47.0%) cases, and dual-chamber or cardiac resynchronization therapy defibrillators in 18 (53.0%) cases. The patients had an average left ventricular ejection fraction of (26.9 +/- 5.5)% (11% to 35%), of which 18 (53.0%) patients had ischemic cardiomyopathy and 16 (47.0%) patients had non-ischemic cardiomyopathy. All patients were followed up at three months after the implantation and every six months thereafter or when prompted by an ICD event.</AbstractText>There were five (14.7%) deaths, including two of heart failure and three with a non-cardiac course, during an average follow-up of (15.0 +/- 11.9) months. Forty-one ICD therapy events were recorded, including 19 (46.3%) appropriate ICD therapies in six patients and 22 (53.7%) inappropriate ICD therapies in four patients with single chamber leads. Inappropriate ICD therapies were mainly due to supraventricular tachyarrhythmias, especially atrial fibrillation. Patients with ischemic cardiomyopathy and non-ischemic cardiomyopathy did not differ in the incidence of either appropriate or inappropriate therapy.</AbstractText>ICD for primary prevention of sudden cardiac death in China prevents patients from arrhythmia death. Relatively high incidence of inappropriate therapies highlights the importance of an atrial lead.</AbstractText> |
5,577 | Distribution of echocardiographic parameters and their associations with cardiovascular risk factors in the Rotterdam Study. | Insight into echocardiographic parameters in the general population may facilitate early recognition of ventricular dysfunction, reducing the population morbidity and mortality of heart failure. We examined the distribution of structural, systolic and diastolic echocardiographic parameters and their associations with cardiovascular risk factors in the Rotterdam Study, a population-based cohort study in men and women aged > or =55 years. Participants with prevalent heart failure, myocardial infarction and atrial fibrillation and flutter were excluded. Echocardiographic parameters were assessed using two-dimensional, M-mode and Doppler echocardiography. Echocardiograms were available in 4,425 participants. Structural parameters were generally larger in men, and most consistently associated with age, body mass index and blood pressure in both sexes. Prevalence of moderate or poor left ventricular systolic function was 3.9% in men and 2.1% in women. Age, body mass index and blood pressure were most consistently associated with systolic function. E/A ratio was lower in women than in men. Age and diastolic blood pressure were most consistently associated with E/A ratio in both sexes. In conclusion, ventricular systolic and diastolic dysfunction is present in asymptomatic individuals. Selected established cardiovascular risk factors are associated with structural, systolic and diastolic parameters. |
5,578 | Non-invasive diagnosis of coronary-subclavian steal: role of the Doppler ultrasound. | Coronary subclavian steal syndrome (CSSS) is a well documented cause of graft function failure in patients after left internal mammary artery (LIMA)--left anterior descending (LAD) coronary artery grafting. We present a case of the CSSS in a patient with cardiac arrest due to ventricular fibrillation. To our knowledge such a case has not yet been described. Patient with a history of LIMA-LAD grafting, complaining only of a mild chronic exertional dyspnoea developed ventricular fibrillation while walking outdoor. After successful resuscitation, blood pressure difference between both arms and abnormal LIMA flow with systolic reversal flow on the Doppler ultrasonography were suggestive of CSSS. Angiography proved the left subclavian artery (LSA) occlusion and coronary angiography confirmed reversal flow in the LIMA graft. Successful percutaneous transluminal angioplasty of the LSA re-established normal LIMA flow and improved the left ventricular hypokinesis and systolic function. |
5,579 | Resuscitation after prolonged cardiac arrest: role of cardiopulmonary bypass and systemic hyperkalemia. | The purpose of this study was to determine (1) the role of emergency cardiopulmonary bypass (CPB) after prolonged cardiac arrest and failed cardiopulmonary resuscitation, and (2) the use of systemic hyperkalemia during CPB to convert intractable ventricular fibrillation (VF).</AbstractText>Thirty-one pigs (34 +/- 2 kg) underwent 15 minutes of cardiac arrest after induced VF, followed by 10 minutes of cardiopulmonary resuscitation-advanced life support. Peripheral CPB was used if cardiopulmonary resuscitation failed to restore stable circulation. Damage was assessed by evaluating hemodynamics, biochemical variables (creatine kinase-MB, neuron-specific enolase), neurologic deficit score, and brain magnetic resonance imaging.</AbstractText>Cardiopulmonary resuscitation alone was successful in only 19% (6 of 31 pigs). Cardiopulmonary bypass was initiated in 81% of animals (25 of 31 pigs) either for hypotension (5 of 25 pigs) or intractable VF (20 of 25 pigs). Defibrillation was successful in 7 of 20 animals during the first 10 minutes after initiating CPB. Ventricular fibrillation persisted more than 10 minutes in 13 of 20 pigs, and animals were treated either with repeated defibrillation (6 of 13 pigs) or with a potassium bolus (7 of 13 pigs) to induce transient cardiac arrest. Overall survival at 24 hours was 84% with cardiopulmonary resuscitation (100% of pigs with hypotension; 71% in CPB-VF < 10 minutes). Despite CPB, fatal myocardial failure occurred after VF duration of more than 10 minutes in all pigs treated with electrical defibrillation, whereas hyperkalemia allowed 100% cardioversion and 86% survival. Biochemical variables remained elevated in all groups. Similarly, severe brain injury was present in all animals as confirmed by neurologic deficit score (197 +/- 10) and magnetic resonance imaging.</AbstractText>Emergency CPB after prolonged cardiac arrest improves survival and allows systemic hyperkalemia to convert intractable VF, but fails to reduce neurologic damage.</AbstractText>2010 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
5,580 | Predictors of successful defibrillation threshold test during CRT-D implantation. | The assessment of defibrillation energy requirement (DER) is a standard practice during cardioverter-defibrillator (ICD) implantation. It is recommended to assure that the energy at least 10 J below the maximal energy deliverable by the implanted device successfully converts the induced ventricular fibrillation (VF). The cardiac resynchronisation therapy with defibrillator (CRT-D) recipients are at increased risk of developing serious complications due to repeated VF induction.</AbstractText>To define the prevalence of high DER among CRT-D recipients and to determine the factors which allow to obtain defibrillation safety margin.</AbstractText>We examined all patients who underwent CRT-D implantation between June 2006 and June 2009 in our institution. The verification of the DER required at least one termination of the induced VF with the energy at least 10 J below the maximal energy deliverable by the implanted device.</AbstractText>The CRT-D was implanted in 65 patients. The first defibrillation test was successful in 57 (88%) patients. In the remaining 8 patients (12%), the defibrillation test was unsuccessful. These patients required system revision: reprogramming shocking polarity (2), reversing polarity and adjusting waveform (3), lead repositioning (1) and adding a subcutaneous lead (2). The use of high output devices (maximal energy > 30 J) and dual-coil leads was associated with a significantly (p < 0.05) lower rate of high DER, although high DER occurred in one patient implanted with the high output device. There was a correlation between the probability of successful defibrillation and renal function. It was less likely to obtain successful defibrillation safety margin in patients with creatinine > 175 micromol/L. During the follow up, ventricular tachyarrhythmia detected in the VF detection zone occurred in 13 (20%) patients, including two patients, who required system modification during implantation. In both cases, VF was terminated by the first defibrillation with the maximal energy of the implanted devices.</AbstractText>High DER occurred in a significant number of CRT-D recipients. There is a correlation between high DER and impaired renal function. The use of high output devices significantly decreases the number of patients who required system modification in order to obtain an adequate defibrillation safety margin.</AbstractText> |
5,581 | Breathing patterns during cardiac arrest. | The absence of respiratory movements is a major criterion recommended for use by bystanders for recognizing an out-of-hospital cardiac arrest (CA), as the persistence of eupneic breathing is considered to be incompatible with CA. The basis for CA-related apnea is, however, uncertain, since brain stem Po(2) is not expected to drop immediately to the critical level where anoxic apnea occurs. It is therefore essential on both clinical and physiological grounds to determine whether and when breathing stops after the onset of CA. In eight patients, we measured the ventilatory response at the onset of ventricular fibrillation (VF) for 12-15 s during the placement of an implantable cardioverter-defibrillator device. We found that regular eupneic breathing was maintained unchanged despite the cessation of systemic and pulmonary blood flow generated by the heart. We extended these findings in adult sheep and found that, as in humans, the normal ventilatory pattern persists unchanged for the first 15 s despite the drop in blood pressure, followed by a progressive increase in minute ventilation, which was sustained for up to 164 s. The ensuing apnea was disrupted by typical gasps occurring at a very slow frequency. These observations suggest a complete "decoupling" between the return of CO(2) to the pulmonary circulation and continued effective respiratory activity, contrary to what we predicted. This delayed cessation of eupneic breathing during the absence of cardiac pump function is likely related to the time needed for brain stem anoxia to develop. These findings challenge the notions that 1) ventilation stops as pulmonary blood flow/cardiac output ceases and 2) the presence of eupneic breathing is a reliable sign of effective cardiac pumping activity. |
5,582 | Prevention of atrial fibrillation by Renin-Angiotensin system inhibition a meta-analysis. | The authors reviewed published clinical trial data on the effects of renin-angiotensin system (RAS) inhibition for the prevention of atrial fibrillation (AF), aiming to define when RAS inhibition is most effective.</AbstractText>Individual studies examining the effects of RAS inhibition on AF prevention have reported controversial results.</AbstractText>All published randomized controlled trials reporting the effects of treatment with angiotensin-converting enzyme inhibitors or angiotensin receptor blockers in the primary or secondary prevention of AF were included.</AbstractText>A total of 23 randomized controlled trials with 87,048 patients were analyzed. In primary prevention, 6 trials in hypertension, 2 trials in myocardial infarction, and 3 trials in heart failure were included (some being post-hoc analyses of randomized controlled trials). In secondary prevention, 8 trials after cardioversion and 4 trials assessing the medical prevention of recurrence were included. Overall, RAS inhibition reduced the odds ratio for AF by 33% (p < 0.00001), but there was substantial heterogeneity among trials. In primary prevention, RAS inhibition was effective in patients with heart failure and those with hypertension and left ventricular hypertrophy but not in post-myocardial infarction patients overall. In secondary prevention, RAS inhibition was often administered in addition to antiarrhythmic drugs, including amiodarone, further reducing the odds for AF recurrence after cardioversion by 45% (p = 0.01) and in patients on medical therapy by 63% (p < 0.00001).</AbstractText>This analysis supports the concept of RAS inhibition as an emerging treatment for the primary and secondary prevention of AF but acknowledges the fact that some of the primary prevention trials were post-hoc analyses. Further areas of uncertainty include potential differences among specific RAS inhibitors and possible interactions or synergistic effects with antiarrhythmic drugs.</AbstractText>Copyright (c) 2010 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
5,583 | Reverse electrical remodeling of the ventricles following successful restoration of sinus rhythm in patients with persistent atrial fibrillation. | Atrial fibrillation (AF) has been shown to be associated with reduced survival and increased ventricular arrhythmogenesis. The purpose of this study was to assess the effects of AF with adequate rate control on the electrophysiologic properties of the ventricles. We hypothesized that AF results in increased ventricular arrhythmogenic risk and that reverse remodeling occurs post-successful cardioversion.</AbstractText>In nine patients with persistent AF, we recorded 12-lead electrocardiograms (ECGs) and 1-hour high-resolution Holter ECGs (H12+, Mortara Instrument, Inc. Milwaukee, WI, USA; recorders [1000 sps] immediately following cardioversion (Day 1) and after 30 days of maintaining sinus rhythm (Day 30). We measured QTc, QT dispersion, and calculated estimates of mean ventricular action potential duration (RT), diastolic interval (DI), T-wave width (TW), T-wave peak-to-end, and their respective scatter on Day 1 and Day 30. Maintenance of normal sinus rhythm was confirmed with a weekly trans-telephonic ECG transmission.</AbstractText>The average QTc interval decreased from 449 ± 28 ms on Day 1 to 422 ± 36 ms on Day 30 (P = 0.04). There was no significant difference in the average QT dispersion. A significant decrease was also noted in DI and TW scatter at Day 30 when compared with Day 1 (P = 0.03 and 0.04, respectively). A decrease in RT scatter was also noted albeit not statistically significant (P = 0.07).</AbstractText>Our results suggest a greater propensity to ventricular arrhythmogenesis in the immediate period following restoration of sinus rhythm and reverse electrical remodeling of the ventricles during the first month after successful maintenance of sinus rhythm. (PACE 2010; 33:1198-1202).</AbstractText>©2010, The Authors. Journal compilation ©2010 Wiley Periodicals, Inc.</CopyrightInformation> |
5,584 | Exercise-induced natriuretic peptide secretion predicts cardioversion outcome in patients with persistent atrial fibrillation: discordant ANP and B-type natriuretic peptide response to exercise testing. | Measurement of natriuretic peptide's (NP) release in response to hemodynamic stress may be complementary to its baseline assessment in individuals. Atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) increase in patients with atrial fibrillation (AF) and decrease after successful cardioversion, suggesting that AF may stimulate secretion of NPs. However, there are conflicting data on the predictive value of NPs on the cardioversion outcome.</AbstractText>The purpose of this study was to investigate whether baseline and exercise-induced NP plasma levels can be useful in predicting successful cardioversion of persistent AF and maintenance of sinus rhythm during 6-month follow-up.</AbstractText>A prospective study enrolled 77 consecutive subjects with persistent AF with normal left ventricular function, referred for elective cardioversion. Patients underwent a modified Bruce protocol treadmill exercise test 24 hours before cardioversion. Blood samples for ANP and BNP analyses were obtained at rest and 5 minutes after exercise peak.</AbstractText>The group of successful cardioversion and stable sinus rhythm presented higher exercise ANP (110.6 ± 41.2 pg/mL vs 43.8 ± 36.1; pg/mL, P < 0.0001) and lower BNP increase (5.2 ± 5.2 pg/mL vs 40.5 ± 34.2 pg/mL, P < 0.0001) than the group of unsuccessful cardioversion or AF recurrence. Using an optimized cutoff level of ≤12% of relative exercise-induced increase in BNP concentration, and of >50 pg/mL of ANP increase, successful cardioversion can be predicted with high accuracy.</AbstractText>An increase in ANP and stability of BNP plasma concentration during exercise testing are independently associated with successful cardioversion and maintenance of sinus rhythm during 6-month follow-up. (PACE 2010; 33:1203-1209).</AbstractText>©2010, The Authors. Journal compilation ©2010 Wiley Periodicals, Inc.</CopyrightInformation> |
5,585 | Ventricular pauses during atrial fibrillation predict relapse after electrical cardioversion: a prospective study. | To investigate the use of ambulatory electrocardiogram (ECG) monitoring in atrial fibrillation (AF) to predict recurrence after electrical cardioversion (ECV).</AbstractText>RR interval variables were obtained from 24 hours ECGs recorded before ECV in 119 patients (85 men, age 66 +/- 10 years) with persistent AF. Patients were followed for 1 month.</AbstractText>Of the 119 patients, 16 (13%) failed ECV and 65 (55%) were in AF at 1 week and 81 (68%) at 1 month after ECV. The maximum RR interval (RR-max) and the minimum RR interval (RR-min) during AF were found to be reproducible. The RR-max was longer in those who had AF 1 week (2.55 +/- 0.49 vs 2.01 +/- 0.52 seconds, P = 0.005) and 1 month (2.56 +/- 0.50 vs 1.89 +/- 0.43 ms; P < 0.001) after ECV than in those who maintained sinus rhythm. Those in AF at 1 month included more patients with RR-max > or = 2.8 seconds (31% vs 11% P = 0.021). The average heart rate was lower in patients with RR-max > or = 2.8 seconds, but the average rate was not predictive of AF recurrence.</AbstractText>Ventricular pauses during AF predict relapse after ECV.</AbstractText> |
5,586 | Therapy with renin-angiotensin system blockers after pulmonary vein isolation in patients with atrial fibrillation: who is a responder? | The data on anti-arrhythmic effect of renin-angiotensin-aldesteron system blockers (RASB) in patients with atrial fibrillation (AF) are controversially discussed. The goal of this analysis was to identify cohort of patients with AF and hypertension, who may have benefit from RASB therapy after pulmonary vein isolation (PVI).</AbstractText>A total of 284 patients with AF and hypertension (paroxysmal AF [PAF]= 218, male = 185, age = 61 years, left ventricular ejection fraction = 60%, coronary artery disease = 42) considered for PVI were included. The patients with PAF were stratified according to time spent in AF (AF burden) within 3 months prior to admission (</> 500 hours). Further patients were divided into two groups: (1) low-burden AF; (2) high-burden AF (PAF and persistent AF). In 195 patients, RASB therapy was administered. A 7-day continuous Holter electrocardiogram was performed after discharge, every 3 months thereafter and by symptoms.</AbstractText>Preventive effect of RASB was revealed in whole group (112 out of 195 [57%] vs 36 out of 89 [40%]; P = 0.025) and was more pronounced in patients with low-burden AF (79 out of 112 [71%] receiving RASB vs 27 out of 55 [49%] being on other drugs; P = 0.013). However, efficiency of RASB failed in patients with high-burden AF (33 out of 83 on RASB [40%] vs nine out of 34 on other drugs [27%]; P = 0.328).</AbstractText>Our data suggest that RASB appears to protect against AF recurrences after PVI in patients with low-burden paroxysmal AF. These results should be tested in a prospective study.</AbstractText>©2010, The Authors. Journal compilation ©2010 Wiley Periodicals, Inc.</CopyrightInformation> |
5,587 | Low-risk profile for malignant ventricular arrhythmias and sudden cardiac death after surgical ventricular reconstruction. | Although it has been recently demonstrated that there was no significant difference in total survival and clinical outcomes between patients who underwent coronary artery bypass grafting (CABG) with or without surgical ventricular reconstruction (SVR), the question of whether or not SVR decreases the arrhythmic risk profile in this population has not been clarified yet.</AbstractText>To determine the real incidence of sudden cardiac death (SCD) and sustained ventricular tachycardia/ventricular fibrillation (sustained VT/VF) in patients following CABG added to SVR and to define their clinical and echocardiographic parameters predicting in-hospital and long-term arrhythmic events (SCD + sustained VT/VF).</AbstractText>Pre- and postoperative clinical and echocardiographic values as well as postoperative electrocardiogram Holter data of 65 patients (21 female, 63 ± 11 years) who underwent SVR + CABG were retrospectively evaluated.</AbstractText> Mean follow-up was 1,105 ± 940 days. At 3 years, the SCD-free rate was 98% and the rate free from arrhythmic events was 88%. Multivariate logistic analysis identified a preoperative left ventricular end-systolic volume index (LVESVI) > 102 mL/m(2) (odds ratio [OR] 1.4, confidence interval [CI] 1.073-1.864, P = 0.02; sensitivity 100%, specificity 94%) and a postoperative pulmonary artery systolic pressure (PASP) > 27 mmHg (OR 2.3, CI 1.887-4.487, P = 0.01; sensitivity 100%, specificity 71%) as independent predictors of arrhythmic events.</AbstractText>Our and previous studies report a low incidence of arrhythmic events in patients following SVR added to CABG, considering the high-risk profile of the study population. A preoperative LVESVI > 102 mL/m(2) and a postoperative PASP > 27 mmHg had a good sensitivity and specificity in predicting arrhythmic events.</AbstractText>©2010, The Authors. Journal compilation ©2010 Wiley Periodicals, Inc.</CopyrightInformation> |
5,588 | Periods of highly synchronous, non-reentrant endocardial activation cycles occur during long-duration ventricular fibrillation. | Periods of Highly Organized Activation During VF.</AbstractText>Little is known about long-duration ventricular fibrillation (LDVF), lasting 1-10 minutes when resuscitation is still possible.</AbstractText>To determine global left ventricle (LV) endocardial activation during LDVF, 6 canines (9.5 ± 0.8 kg) received a 64-electrode basket catheter in the LV, a right ventricular (RV) catheter, and a 12-lead electrocardiogram (ECG). Activation sequences of 15 successive cycles after initiation and after 1, 2, 3, 5, 7, and 10 minutes of LDVF were determined. Early during VF, LV endocardial activation was complex and present throughout most (78.0 ± 9.7%) of each cycle consistent with reentry. After 3-7 minutes of LDVF in 5 animals, endocardial activation became highly synchronized and present for only a small percentage of each cycle (18.2 ± 7.7%), indicating that LV endocardial reentry was no longer present. During this synchronization, activations arose focally in Purkinje fibers and spread as large wavefronts to excite the Purkinje system followed by the subendocardial working myocardium. During this synchronization, the ECG continued to appear irregular, consistent with VF, and LV cycle length (183 ± 29 ms) was significantly different than RV cycle length (144 ± 14 ms) and significantly different than the LV cycle length when synchronization was not present (130 ± 11 ms).</AbstractText>After 3-7 minutes of LDVF, a highly organized, synchronous, focal LV endocardial activation pattern frequently occurs that is not consistent with reentry but is consistent with triggered activity or abnormal automaticity in Purkinje fibers. The ECG continues to appear irregular during this period, partially because of differences in LV and RV cycle lengths.</AbstractText>© 2010 Wiley Periodicals, Inc.</CopyrightInformation> |
5,589 | Autonomic dysfunction and new-onset atrial fibrillation in patients with left ventricular systolic dysfunction after acute myocardial infarction: a CARISMA substudy. | Atrial fibrillation (AF) increases morbidity and mortality in patients with previous myocardial infarction and left ventricular systolic dysfunction. The purpose of this study was to identify patients with a high risk for new-onset AF in this population using invasive and noninvasive electrophysiological tests.</AbstractText>The study included 271 patients from the Cardiac Arrhythmias and RIsk Stratification after Myocardial InfArction (CARISMA) study with an acute myocardial infarction (AMI) and left ventricular ejection fraction ≤40% without previous AF at enrollment. Within 21 days after the AMI, an implantable loop recorder was inserted and used to diagnose AF over the 2-year study duration. The following tests were performed: heart rate variability (HRV) and turbulence (HRT) analyses from repeated 24-hour Holter recordings, 2-dimensional (2D)-echocardiograms, exercise test, and programmed electrophysiologic stimulation.</AbstractText>A total of 101 patients (37%) developed AF during the study. Predictive measures included several indexes of HRV including reduced low-frequency (LF) power from spectral HRV analysis (adjusted HR = 1.6, P = 0.034), HRT slope ≤2.5 (HR = 1.6, P = 0.032) and Detrended Fluctuation Analysis (DFA1) from HRV analysis (HR = 1.8, P = 0.011); all are measures of cardiac autonomic nervous system dysfunction. Combined with age >60 years, low values for LF, HRT slope, and DFA1 provided a powerful risk score for prediction of new-onset AF (1-2 points: HR = 4.3, P = 0.001, 3-4 points: HR = 7.0, P < 0.001).</AbstractText>Abnormal HRV and HRT parameters, which are associated with disturbances in the cardiac autonomic regulation, are associated with increased risk of new-onset AF independently of conventional clinical risk variables.</AbstractText>© 2010 Wiley Periodicals, Inc.</CopyrightInformation> |
5,590 | Ventricular tachyarrhythmia associated with hypertrophic cardiomyopathy: incidence, prognosis, and relation to type of hypertrophy. | To assess the incidence, characteristics, and prognosis of ventricular tachyarrhythmia in hypertrophic cardiomyopathy (HCM).</AbstractText>The study consisted of 66 consecutive patients with HCM who were admitted to Niigata University Hospital between 1992 and 2005. Their clinical characteristics and ECG morphology were investigated according to the type of HCM.</AbstractText>The type of HCM was asymmetric hypertrophy (ASH) in 34 patients (51%), obstructive HCM (HOCM) in 9 (14%), apical HCM (ApHCM) in 14 (21%), and midventricular obstruction (MVO) in 9 (14%). The cause of admission was ventricular tachyarrhythmia in 25 patients (38%), unexplained syncope in 11 (17%), and heart failure in 30 (45%). Sustained monomorphic ventricular tachycardia (SMVT) occurred in 19 patients and ventricular fibrillation in 6. In the 19 patients with SMVT, 12 had MVO and 3 of these had previous apHCM. Six of the 19 patients with SMVT had ASH, and 3 had abnormal apical wall motion. In 14 patients, the SMVT appeared to originate from the apical aneurysm based on the morphology of the tachycardia. Ventricular tachyarrhythmia recurred in 14 of the 25 patients (56%), and 4 of the 18 patients with an ICD had electrical storm. ASH with abnormal wall motion of the LV apex or MVO was recognized in the 4 patients with electrical storm; they commonly had abnormal Q waves and ST elevation in leads V4-V6.</AbstractText>Ventricular tachyarrhythmia was responsible for 38% of hospitalizations in HCM, and SMVT occurred in patients with MVO and/or with abnormal wall motion of the LV apex. Electrical storm was more common in patients with ST elevation in precordial leads V4-V6.</AbstractText>© 2010 Wiley Periodicals, Inc.</CopyrightInformation> |
5,591 | The relation between the color M-mode propagation velocity of the descending aorta and coronary and carotid atherosclerosis and flow-mediated dilatation. | To improve clinical outcomes, noninvasive imaging modalities have been proposed to measure and monitor atherosclerosis. Common carotid intima-media thickness (CIMT) and brachial artery flow-mediated dilatation (FMD) have correlated with coronary atherosclerosis. Recently, the color M-mode-derived propagation velocity of descending thoracic aorta (AVP) was shown to be associated with coronary artery disease (CAD).</AbstractText>CIMT, FMD, and AVP were measured in 92 patients with CAD and 70 patients having normal coronary arteries (NCA) detected by coronary angiography. Patients with acute myocardial infarction, renal failure or hepatic failure, aneurysm of aorta, severe valvular heart disease, left ventricular ejection fraction <40%, atrial fibrillation, frequent premature beats, left bundle branch block, and inadequate echocardiographic image quality were excluded.</AbstractText>Compared to patients with normal coronary arteries, patients having CAD had significantly lower AVP (29.9 +/- 8.1 vs. 47.5 +/- 16.8 cm/sec, P < 0.001) and FMD (5.3 +/- 1.9 vs. 11.4 +/- 5.8%, P < 0.001) and higher CIMT (0.94 +/- 0.05 vs. 0.83 +/- 0.14 mm, P < 0.001) measurements. There were significant correlations between AVP and CIMT (r =-0.691, P < 0.001), AVP and FMD (r = 0.514, P < 0.001) and FMD and CIMT (r =-0.530, P < 0.001).</AbstractText>The transthoracic echocardiographic determination of the color M-mode propagation velocity of the descending aorta is a simple practical method and correlates well with the presence of carotid and coronary atherosclerosis and brachial endothelial function.</AbstractText> |
5,592 | Intracardiac echocardiography in electrophysiology. | Intracardiac echocardiography (ICE) is a recent, invaluable tool which can provide real-time anatomical guidance in electrophysiological procedures. By inserting intravenously an ultrasound probe and advancing it into the heart, various different views can be obtained which allow to better visualize patient anatomy, to guide the placement of electrophysiological catheters, and to detect immediately procedural complications as they occur. In atrial fibrillation ablation, ICE proves particularly useful to achieve a safer trans-septal puncture (especially in the presence of anatomical anomalies of the interatrial septum) and to help to monitor the visualization of the mapping catheters (circular, high density), or the monitoring of the balloons catheter (Cryo, Laser) position. In ventricular tachycardia ablation, on the other hand, ICE allows for continuous correlation between electrophysiological and structural findings (such as wall motion anomalies or changes in echodensity), and helps to ensure correct catheter contact and to position it, particularly around delicate structures such as the aortic cusps. In any procedure, ICE is also useful to immediately detect procedural complications, such as thrombus formation along catheters, or pericardial effusion. Thanks to its real-time morphological information, ICE provides an ideal complement to simple fluoroscopy or to more complex electroanatomic mapping techniques and is set to gain a wider role in a broad range of electrophysiological procedures. |
5,593 | Chronic kidney disease as an independent risk factor for new-onset atrial fibrillation in hypertensive patients. | Chronic kidney disease (CKD) has recently been recognized to be a powerful predictor of cardiovascular morbidity and mortality. Atrial fibrillation (AF), which is a common arrhythmia in hypertensives, is associated with increased risks of cardiovascular events and death. However, the association between CKD and the onset of AF has not been fully elucidated. The present study assessed the hypothesis that CKD may influence the onset of AF in hypertensives.</AbstractText>A total of 1118 hypertensive patients (mean age, 63 years) without previous paroxysmal AF, heart failure, myocardial infarction, or valvular disease were enrolled. CKD was defined as decreased glomerular filtration rate (<60 ml/min per 1.73 m) and/or the presence of proteinuria (>or=1+).</AbstractText>During follow-up periods (mean, 4.5 years), 57 cases of new-onset AF were found (1.1% per year). Kaplan-Meier curves revealed that the cumulative AF event-free rate was decreased in the CKD group (log-rank test P < 0.001). By univariate Cox regression analysis, age, smoking, left atrial dimension, left ventricular mass index, and the presence of CKD were significantly associated with the occurrence of AF. Among these possible predictors, CKD (hazard ratio 2.18, P = 0.009) was an independent determinant for the onset of AF in multivariate analysis. Advanced stages of CKD (stages 4 and 5) were strongly related to the increased occurrence of AF.</AbstractText>The present study demonstrated that the complication of CKD, especially progressed renal dysfunction, was a powerful predictor of new-onset AF in hypertensive patients, independently of left ventricular hypertrophy and left atrial dilatation.</AbstractText> |
5,594 | Single-site Bachmann's bundle pacing is beneficial while coronary sinus pacing results in echocardiographic right heart pacemaker syndrome in brady-tachycardia patients. | It has been proposed that multisite atrial pacing (MSAp) restores atrial electrical activation and prevents atrial fibrillation recurrence; however, single-site Bachmann's bundle pacing (BBp) has also been reported as providing effective atrial resynchronization. Coronary sinus pacing (CSp) leads to reversed impulse propagation within the atria.</AbstractText>Acute echocardiographic examination was performed in 15 healthy subjects, and in 25 patients with sinus node dysfunction and recurrent atrial fibrillation during MSAp (atrial leads in the BB area and CS ostium), and single-site BBp and CSp. Regional atrial synchrony was assessed by tissue Doppler echocardiography. Pacing mode had no effect on stroke volume. CSp resulted in right atrial filling diminution, shortened mechanical atrioventricular delay in the right heart and diminished right ventricular inflow. The magnitude of reversion of the physiological right-to-left atrial contraction sequence was most prominent during CSp (15+/-11, 12+/-23, 3+/-21, 42+/-23 ms; control, MSAp, BBp, CSp respectively, P<0.0001). BBp provided the best atrial contraction synchrony, and had a comparable effect on global cardiac function to MSAp.</AbstractText>Single-site BBp provides comparable hemodynamics to MSAp and is sufficient to restore atrial contraction synchrony. Single-site CSp induced echocardiographic pacemaker syndrome in the right heart.</AbstractText> |
5,595 | Short-term fluctuations of plasma NT-proBNP levels in patients with new-onset atrial fibrillation: a way to assess time of onset? | The objective of this study was to characterise short-term kinetics of plasma amino-terminal pro-B natriuretic peptide (NT-proBNP) levels in patients with new-onset atrial fibrillation (AF) without heart failure.</AbstractText>Prospective cohort study.</AbstractText>Emergency departments and inpatient services of three large community hospitals.</AbstractText>31 consecutive patients with new-onset atrial fibrillation (<24 h before presentation) persisting at least 48 h, without evidence of heart failure.</AbstractText>Plasma NT-proBNP levels were obtained at presentation and then 6, 12, 18, and 24 h after presentation. A final sample was obtained 48 h after onset of AF.</AbstractText>Mean plasma NT-proBNP levels and 95% CIs (pg/ml) during the 48-h period following onset of AF were: 0-6 h: 636 (395 to 928), 6-12 h: 1364 (951 to 1778), 12-18 h: 1747 (1412 to 2083), 18-24 h: 1901 (1549 to 2253), 24-36 h: 1744 (1423 to 2066) and 36-48 h: 1101 (829 to 1373). Mean time to peak NT-proBNP levels was 16.7 (0.7) h; 29 patients reached their peak levels within 24 h. The mean peak NT-proBNP level was significantly higher than those obtained at 0-6 h and at 36-48 h after onset of AF (p<0.001 for both). There was no correlation between ventricular rate and plasma NT-proBNP levels during any time period after onset of AF.</AbstractText>In patients with new-onset AF but no clinical or radiographic evidence of heart failure, plasma NT-proBNP levels rise progressively to a peak during the first 24 h and then rapidly fall. This pattern may serve as an aid to assess the time from AF onset.</AbstractText> |
5,596 | Delayed versus immediate defibrillation for out-of-hospital cardiac arrest due to ventricular fibrillation: A systematic review and meta-analysis of randomised controlled trials. | Human studies over the last decade have indicated that delaying initial defibrillation to allow a short period of cardiopulmonary resuscitation (CPR) may promote a more responsive myocardial state that is more likely to respond to defibrillation and result in increased rates of restoration of spontaneous circulation (ROSC) and/or survival. Out-of-hospital studies have produced conflicting results regarding the benefits of CPR prior to defibrillation in relation to survival to hospital discharge. The aim of this study was to conduct a systematic review and meta-analysis of randomised controlled trials comparing the effect of delayed defibrillation preceded by CPR with immediate defibrillation on survival to hospital discharge.</AbstractText>A systematic literature search of key electronic databases including Medline, EMBASE, and the Cochrane Library was conducted independently by two reviewers. Randomised controlled trials meeting the eligibility criteria were critically appraised according to the Cochrane Group recommended methodology. Meta-analyses were conducted for the outcomes of survival to hospital discharge overall and according to response time of emergency medical services.</AbstractText>Three randomised controlled trials were identified which addressed the question of interest. All included studies were methodologically appropriate to include in a meta-analysis. Pooled results from the three studies demonstrated no benefit from providing CPR prior to defibrillation compared to immediate defibrillation for survival to hospital discharge (OR 0.94 95% CI 0.46-1.94). Meta-analysis of results according to ambulance response time (</=5min or >5min) also showed no difference in survival rates.</AbstractText>Delaying initial defibrillation to allow a short period of CPR in out-of-hospital cardiac arrest due to VF demonstrated no benefit over immediate defibrillation for survival to hospital discharge irrespective of response time. There is no evidence that CPR before defibrillation is harmful. Based on the existing evidence, EMS jurisdictions are justified continuing with current practice using either defibrillation strategy.</AbstractText>Copyright 2010 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
5,597 | Incidence of re-arrest and critical events during prolonged transport of post-cardiac arrest patients. | To determine the feasibility of transporting post-cardiac arrest patients to tertiary-care facilities, the rate of re-arrest, and the rate of critical events during critical care transport team (CCTT) care.</AbstractText>Retrospective chart review of cardiac arrest patients transported via CCTT between 1/1/2001 and 5/31/2009. Demographic information, re-arrest, and critical events during transport were abstracted. We defined critical events as hypotension (systolic blood pressure<90mmHg), hypoxia (oxygen saturation<90%), or both hypotension and hypoxia at any time during CCTT care. Comparisons were performed using Chi-squared test and a Cox proportional hazards model was employed to determine predictors of events.</AbstractText>Of the 248 patients studied, the majority was male (61%), presented in ventricular fibrillation or ventricular tachycardia (VF/VT, 50%), and comatose (80%). Re-arrest was uncommon (N=15; 6%). Critical events affected 58 patients (23%) during transport. Median transport time was 63min (IQR 51, 81) in both those who experienced a critical event and those who did not. Vasopressor use was associated with any decompensation during CCTT (Hazard Ratio 1.81; 95%CI 1.29, 2.54). Three patients (20%) suffering re-arrest survived to hospital discharge. Survival (Chi square 11.77; p<0.01) and good neurologic outcome (Chi square 5.93; p=0.01) were higher in patients who did not suffer any event during transport.</AbstractText>Transport of resuscitated cardiac arrest patients to a tertiary-care facility via CCTT is feasible, and the duration of transport is not associated with re-arrest during transport. Repeat cardiac arrest occurs infrequently, while critical events are more common. Outcomes are worse in those experiencing an event.</AbstractText>Copyright 2010 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
5,598 | Mechanisms underlying the antifibrillatory action of hyperkalemia in Guinea pig hearts. | Hyperkalemia increases the organization of ventricular fibrillation (VF) and may also terminate it by mechanisms that remain unclear. We previously showed that the left-to-right heterogeneity of excitation and wave fragmentation present in fibrillating guinea pig hearts is mediated by chamber-specific outward conductance differences in the inward rectifier potassium current (I(K1)). We hypothesized that hyperkalemia-mediated depolarization of the reversal potential of I(K1) (E(K1)) would reduce excitability and thereby reduce VF excitation frequencies and left-to-right heterogeneity. We induced VF in Langendroff-perfused guinea pig hearts and increased the extracellular K(+) concentration ([K(+)](o)) from control (4 mM) to 7 mM (n = 5) or 10 mM (n = 7). Optical mapping enabled spatial characterization of excitation dominant frequencies (DFs) and wavebreaks, and identification of sustained rotors (>4 cycles). During VF, hyperkalemia reduced the maximum DF of the left ventricle (LV) from 31.5 +/- 4.7 Hz (control) to 23.0 +/- 4.7 Hz (7.0 mM) or 19.5 +/- 3.6 Hz (10.0 mM; p < 0.006), the left-to-right DF gradient from 14.7 +/- 3.6 Hz (control) to 4.4 +/- 1.3 Hz (7 mM) and 3.2 +/- 1.4 Hz (10 mM), the number of DF domains, and the incidence of wavebreak in the LV and interventricular regions. During 10 mM [K(+)](o), the rotation period and core area of sustained rotors in the LV increased, and VF often terminated. Two-dimensional computer simulations mimicking experimental VF predicted that clamping E(K1) to normokalemic values during simulated hyperkalemia prevented all of the hyperkalemia-induced VF changes. During hyperkalemia, despite the shortening of the action potential duration, depolarization of E(K1) increased refractoriness, leading to a slowing of VF, which effectively superseded the influence of I(K1) conductance differences on VF organization. This reduced the left-to-right excitation gradients and heterogeneous wavebreak formation. Overall, these results provide, to our knowledge, the first direct mechanistic insight into the organization and/or termination of VF by hyperkalemia. |
5,599 | Intracardiac echocardiography in complex cardiac catheter ablation procedures. | With the availability of catheter ablation for the elimination of complex cardiac arrhythmias, new imaging tools have enhanced the safety and efficacy of procedures performed in the electrophysiology laboratory. We review the use of intracardiac ultrasound (ICE) as the modality that allows real-time monitoring and reconstruction of cardiac anatomy. Practical technical information related to the use of ICE in ablation procedures in general and particular aspects related to ablation of atrial fibrillation, atrial flutter, ventricular tachycardia, and arrhythmias in adults with congenital heart disease are discussed in this manuscript. |
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