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5,800 | Unusual features of apical hypertrophic cardiomyopathy. | Apical hypertrophic cardiomyopathy (HC) is commonly regarded as a relatively benign condition of young to middle-aged Japanese men. Apical HC in a predominantly Caucasian population is not well characterized. The cardiovascular characteristics, morbidity, and mortality of a series of elderly, predominantly Caucasian subjects with apical HC are described. Thirty-two consecutive patients with apical HC (mean age 71 years, 15 men) were identified from a teaching hospital without a specialized HC clinic. Twenty-three subjects were Caucasian, 8 were Asian, and none Japanese. Twenty-two patients had coexistent hypertension. Six patients had documented late evolution of apical HC on electrocardiography and echocardiography up to 5 years after previous documented normal left ventricular morphology on echocardiography. The diagnosis of apical HC was initially missed in 7 patients because of inadequate image quality of the left ventricular apex and a lack of awareness of the condition. The correct diagnosis was assigned to all 7 patients after repeat echocardiography. Six of 13 patients who underwent coronary angiography had associated coronary artery fistulae. One patient required an implantable defibrillator for exertional syncope. Ten of the patients developed atrial fibrillation, 6 of whom had complicating thromboembolic events. Of the 6 deaths in the cohort, 2 followed atrial fibrillation-related hemiplegic strokes, and 2 followed progressive heart failure. In conclusion, apical HC in a teaching hospital without a specialized HC clinic and in a predominantly Caucasian population is a disease of the elderly. Documented late morphologic evolution is not uncommon, with a high incidence of coronary fistulae and morbid atrial fibrillation. |
5,801 | Relationships between emerging measures of heart failure processes of care and clinical outcomes. | Previous studies have not confirmed associations between some current performance measures for inpatient heart failure processes of care and postdischarge outcomes. It is unknown if alternative measures are associated with outcomes.</AbstractText>Using data for 20,441 Medicare beneficiaries in OPTIMIZE-HF from March 2003 through December 2004, which we linked to Medicare claims data, we examined associations between hospital-level processes of care and patient outcomes. Performance measures included any beta-blocker for patients with left ventricular systolic dysfunction (LVSD); evidence-based beta-blocker for patients with LVSD; warfarin for patients with atrial fibrillation; aldosterone antagonist for patients with LVSD; implantable cardioverter-defibrillator for patients with ejection fraction < or =35%; and referral to disease management. Outcome measures were unadjusted and adjusted associations of each process measure with 60-day and 1-year mortality and cardiovascular readmission at the hospital level.</AbstractText>Adjusted hazard ratios for 1-year mortality with a 10% increase in hospital- level adherence were 0.94 for any beta-blocker (95% CI, 0.90-0.98; P = .004), 0.95 for evidence-based beta-blocker (95% CI, 0.92-0.98; P = .004); 0.97 for warfarin (95% CI, 0.92-1.03; P = .33); 0.94 for aldosterone antagonists (95% CI, 0.91-0.98; P = .006); 0.92 for implantable cardioverter-defibrillator (95% CI, 0.87-0.98; P = .007); and 1.01 for referral to disease management (95% CI, 0.99-1.03; P = .21).</AbstractText>Several evidence-based processes of care are associated with improved outcomes, can discriminate hospital-level quality of care, and could be considered as clinical performance measures.</AbstractText> |
5,802 | The prognostic impact of shocks for clinical and induced arrhythmias on morbidity and mortality among patients with implantable cardioverter-defibrillators. | Recent investigations have demonstrated that the occurrence of implantable cardioverter-defibrillator (ICD) shocks is associated with adverse long-term outcomes. These studies have emphasized that the risk is most reasonably due to arrhythmias rather than to the shock itself. We sought to compare the impact of shock delivery for induced ventricular arrhythmias during implantation defibrillation threshold testing and noninvasive electrophysiology study (NIPS) to clinical shocks on long-term outcomes among patients with ICDs.</AbstractText>This was a cohort evaluation of 1,372 patients undergoing ICD implantation at a tertiary hospital from December 1997 to January 2007. The probability of all-cause mortality and hospitalization for acute decompensated heart failure (ADHF) was evaluated based upon the type of ICD shock received using multivariable Cox proportional analyses. The four shock types analyzed were implantation shocks only (n = 694), additional NIPS shocks only (n = 319), additional appropriate shocks only (n = 128), or additional inappropriate shocks only (n = 104).</AbstractText>The risk of death (adjusted hazard ratio [AHR] 0.91 [95% confidence interval (CI) 0.69-1.20]; P = .491) or ADHF (AHR 0.71 [95% CI 0.46-1.16]; P = .277) were similar between recipients of NIPS shocks and recipients of implantation shocks. Receiving an appropriate ICD shock increased the risk of death (AHR 2.09 [95% CI 1.38-2.69]; P <.001) and ADHF (AHR 2.40 [95% CI 1.51-3.81]; P <.002) as compared with implantation shocks and also increased the risk of death (AHR 2.61 [95% CI 1.86-3.67]; P <.001) and ADHF (AHR 2.29 [95% CI 1.33-3.97]; P = .003) as compared with NIPS shocks.</AbstractText>ICD shocks delivered during induced ventricular arrhythmias at the time of NIPS testing does not increase the risk of death or ADHF as compared with recipients of appropriate ICD shocks. The occurrence of spontaneous arrhythmias in vulnerable substrates may explain the increased risk.</AbstractText>Copyright (c) 2010. Published by Elsevier Inc.</CopyrightInformation> |
5,803 | Periodic acceleration (pGz) prior to whole body ischemia reperfusion injury provides early cardioprotective preconditioning. | Periodic acceleration (pGz) is a method that applies repetitive sinusoidal head-to-foot motion to the horizontally positioned body. pGz adds pulses to the circulation as a function of frequency, thereby increasing shear stress to the endothelium. Pulsatile shear stress increases release of cardioprotective endothelial-derived nitric oxide prostaglandin E-2 and prostacyclin into the circulation. We investigated whether pGz may be effective as an early preconditioning strategy when applied one hour prior to whole body ischemia reperfusion injury induced by ventricular fibrillation (VF).</AbstractText>Twenty anesthetized and paralyzed male swine were randomized to one hour of pGz and conventional mechanical ventilation [PC] or solely conventional mechanical ventilation [Control] prior to VF and resuscitation. After eight minutes of unsupported VF, cardiopulmonary resuscitation was carried out followed by defibrillation. Hemodynamics, electrocardiogram, echocardiogram, regional blood flows, and markers of global myocardial injury were measured. Protein expression of endothelial-derived nitric oxide synthase (eNOS), phosphorylated eNOS (p-eNOS), serine/threonine kinase Akt total (t-Akt), and phosphorylated (p-Akt) were determined by immunoblotting.</AbstractText>All animals had spontaneous return of circulation after cardiopulmonary resuscitation (CPR) and defibrillation. Preconditioned animals had less hemodynamically significant arrhythmias, less myocardial stunning, and greater regional blood flows to the brain, heart, kidneys, and ileum than Controls. Troponin I and creatine phosphokinase values in PC were 65% of the values present in Controls. In addition, preconditioned animals had higher protein expression of cardiac eNOS, p-eNOS, t-Akt, and p-Akt than Controls.</AbstractText>pGz preconditioning confers early cardioprotection in a model of whole body ischemia reperfusion injury.</AbstractText>Copyright 2010 Elsevier Inc. All rights reserved.</CopyrightInformation> |
5,804 | Intra-arrest selective brain cooling improves success of resuscitation in a porcine model of prolonged cardiac arrest. | We have previously demonstrated that early intra-nasal cooling improved post-resuscitation neurological outcomes. The present study utilizing a porcine model of prolonged cardiac arrest investigated the effects of intra-nasal cooling initiated at the start of cardiopulmonary resuscitation (CPR) on resuscitation success. Our hypothesis was that rapid nasal cooling initiated during "low-flow" improves return of spontaneous resuscitation (ROSC).</AbstractText>In 16 domestic male pigs weighing 40+/-3 kg, VF was electrically induced and untreated for 15 min. Animals were randomized to either head cooling or control. CPR was initiated and continued for 5 min before defibrillation was attempted. Coincident with starting CPR, the hypothermic group was cooled with a RhinoChill device which produces evaporative cooling in the nasal cavity of pigs. No cooling was administrated to control animals. If ROSC was not achieved after defibrillation, CPR was resumed for 1 min prior to the next defibrillation attempt until either successful resuscitation or for a total of 15 min.</AbstractText>Seven of eight animals in the hypothermic group (87.5%) and two of eight animals in control group (25%) (p=0.04) were successfully resuscitated. At ROSC, brain temperature was increased from baseline by 0.3 degrees C in the control group, and decreased by 0.1 degrees C in the hypothermic animals. Pulmonary artery temperature was above baseline in both groups.</AbstractText>Intra-nasal cooling initiated at the start of CPR significantly improves the success of resuscitation in a porcine model of prolonged cardiac arrest. This may have occurred by preventing brain hyperthermia.</AbstractText>Copyright 2010 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
5,805 | The relationship between time to arrival of emergency medical services (EMS) and survival from out-of-hospital ventricular fibrillation cardiac arrest. | We examined the relationship between time from collapse to arrival of emergency medical services (EMS) and survival to hospital discharge for out-of-hospital ventricular fibrillation cardiac arrests in order to determine meaningful interpretations of this association.</AbstractText>We calculated survival rates in 1-min intervals from collapse to EMS arrival. Additionally, we used logistic regression to determine the absolute probability of survival per minute of delayed EMS arrival. We created a logistic regression model with spline terms for the time variable to examine the decline in survival in intervals that are hypothesized to be physiologically relevant.</AbstractText>The observed data showed survival declined, on average, by 3% for each minute that EMS was delayed following collapse. Survival rates did not decline appreciably if the time between collapse and arrival of EMS was 4 min or less but they declined by 5.2% per minute between 5 and 10 min. EMS arrival 11-15 min after collapse showed a less steep decline in survival of 1.9% per minute. The spline model that incorporated changes in slope in the time interval variable modeled this relationship more accurately than a model with a continuous term for time (p=0.01).</AbstractText>The results of our analyses show that survival from out-of-hospital cardiac arrest does not decline at a constant rate following collapse. Models that incorporate changes that reflect the physiological alterations that occur following cardiac arrests are a more accurate way to describe changes in survival rates over time than models that include only a continuous term for time.</AbstractText>Copyright 2010 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
5,806 | Vagal tone augmentation to the atrioventricular node in humans: efficacy and safety of burst endocardial stimulation. | Control of atrioventricular (AV) nodal conduction by endocardial stimulation of efferent AV nodal vagal fibers [atrioventricular nodal vagal stimulation (AVNS)] is a promising approach for long-term device-based modulation of ventricular rate during atrial fibrillation (AF). However, few data on the efficacy of AVNS delivered as high-frequency stimulus packages (burst AVNS) in humans are available.</AbstractText>The purpose of this study was to determine whether burst AVNS can to modulate AV nodal conduction during AF and whether burst AVNS delivered during sinus rhythm (SR) in the effective atrial refractory period allows safe implantation of a permanent lead in a position suitable for AVNS.</AbstractText>Twenty patients (10 in SR and 10 in AF) who were candidates for dual-chamber pacemaker implantation for sick sinus syndrome were enrolled in the study. The posteroseptal right atrium was mapped to identify a location at which burst AVNS would achieve AV nodal conduction modulation (lengthening of PR interval in SR and reduction of ventricular rate in AF). Subsequently, a lead was screwed in at that site and burst stimulation (pulse rate 50 Hz, burst duration 180 ms) was delivered at different burst rates, pulse durations, and amplitudes.</AbstractText>In all SR patients, PR-interval prolongation was evoked at 90 and 120 bursts/minute with pulse durations < or =1 ms. Specifically, the mean voltages required to obtain PR-interval prolongation and advanced AV block were 4.3 +/- 2.2 V and 5.4 +/- 1.8 V (at 90 bursts/minute and 1 ms), respectively. Similarly, ventricular rate reduction was obtained in all AF patients, starting from 90 bursts/minute and 0.5-ms pulse duration (at 5.4 +/- 1.8 V). Ventricular arrhythmias were never induced during AVNS.</AbstractText>Endocardial right atrial burst AVNS reduces ventricular rate during AF. Burst AVNS delivered during SR in the effective atrial refractory period allows optimization of lead positioning for AVNS.</AbstractText>Copyright 2010 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
5,807 | High prevalence of early repolarization in short QT syndrome. | Short QT syndrome (SQTS) is characterized by an abnormally short QT interval and sudden death. Due to the limited number of cases, the characteristics of SQTS are not well understood. It has been reported recently that early repolarization is associated with idiopathic ventricular fibrillation and the QT interval is short in patients with early repolarization.</AbstractText>The purpose of this study was to study the association between early repolarization and arrhythmic events in SQTS.</AbstractText>The study consisted of three cohorts: SQTS cohort (N = 37), control cohort with short QT interval and no arrhythmic events (N = 44), and control cohort with normal QT interval (N = 185). ECG parameters were compared among the study cohorts.</AbstractText>Heart rate, PR interval, and QRS duration were similar among the three study cohorts. Early repolarization was more common in the SQTS cohort (65%) than in the short QT control cohort (30%) and the normal QT control cohort (10%). Duration from T-wave peak to T-wave end was longer in the SQTS cohort than in the short QT control cohort, although QT and corrected QT intervals were similar. In the SQTS cohort, there were more males among patients with arrhythmic events than in those with a family history but without arrhythmic events. In multivariate models, early repolarization was associated with arrhythmic events in the SQTS cohort. ECG parameters including QT and QTc intervals were not associated with arrhythmic events in the SQTS cohort.</AbstractText>There is a high prevalence of early repolarization in patients with SQTS. Early repolarization may be useful in identifying risk of cardiac events in SQTS.</AbstractText>Copyright 2010 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
5,808 | Pilsicainide. | Pilsicainide is a class Ic antiarrhythmic agent used for the treatment of supraventricular and ventricular tachycardia. The pharmacodynamic effects of pilsicainide are achieved via selective sodium channel blockade. In randomized, multicentre trials in patients with atrial fibrillation, restoration of sinus rhythm was achieved in significantly more patients treated with a single oral dose of pilsicainide than those who received placebo, and in a numerically higher proportion of oral pilsicainide than intravenous disopyramide recipients. In another well designed trial in patients with persistent atrial fibrillation, the proportion of patients whose arrhythmia converted to normal sinus rhythm was significantly higher among those randomized to receive 2 weeks of oral pilsicainide therapy than among patients who received placebo. Over a 1-year period, both pilsicainide and cibenzoline (another class Ic agent) were effective in preventing recurrence of atrial fibrillation in a substantial proportion of patients in a single-centre crossover trial. There were no between-group differences in the subgroup of patients with shorter-duration atrial fibrillation, but actuarial results over 1 year significantly favoured cibenzoline over pilsicainide in patients with longer-duration atrial fibrillation. Both oral and intravenous pilsicainide have demonstrated efficacy in ventricular tachyarrhythmias, including ventricular extrasystole. Clinical trial and postmarketing surveillance data indicate that pilsicainide is generally well tolerated in most patients. |
5,809 | Use of the wearable external cardiac defibrillator in children. | The wearable cardiac defibrillator (WCD) is an alternative to the implantation of cardioverter defibrillator (ICD) for patients at risk for sudden death who do not fulfill standard criteria for ICD implantation or in whom the risk:benefit ratio is equivocal. Published data pertaining to the WCD in children is sparse. We describe the utility of the WCD in children at a single tertiary care center.</AbstractText>We retrospectively identified all patients aged birth to 18 years of age who were prescribed a WCD between January 1, 2007, and June 30, 2009. Patient information regarding diagnosis, clinical history, electrocardiograms, rhythm reports, and outcome at last follow-up was reviewed. Information regarding the WCD was obtained including indication for use, patient compliance, and accuracy of rhythm determination, inappropriate and appropriate shock events, and other complications.</AbstractText>Since 2007, four patients age less than or equal to 18 years have been prescribed the WCD at our institution. None of the patients had an inappropriate shock. Two patients had documented noncompliance with wear, which resulted in failure to detect and treat a life-threatening arrhythmia in one. Two patients required downsizing of the WCD during use in order to improve electrode contact and rhythm detection.</AbstractText>The WCD is an option for children of appropriate size who are at increased risk for sudden cardiac death, but in whom the risk of ICD implantation outweighs the benefit. Careful patient selection and education is important to ensure safety, as noncompliance with wear was common in this series of children.</AbstractText> |
5,810 | Atrial-selective sodium channel block as a novel strategy for the management of atrial fibrillation. | Safe and effective pharmacologic management of atrial fibrillation (AF) is one of the greatest challenges facing an aging society. Currently available pharmacologic strategies for rhythm control of AF are associated with ventricular arrhythmias and in some cases multi-organ toxicity. Consequently, drug development has focused on atrial-selective agents such as IKur blockers. Recent studies suggest that IKur block alone may be ineffective for suppression of AF and may promote AF in healthy hearts. Recent experimental studies have demonstrated other important electrophysiologic differences between atrial and ventricular cells, particularly with respect to sodium channel function, and have identified sodium channel blockers that exploit these electrophysiologic distinctions. Atrial-selective sodium channel blockers, such as ranolazine and amiodarone, effectively suppress and/or prevent the induction of AF in experimental models, while producing little to no effect on ventricular myocardium. These findings suggest that atrial-selective sodium channel block may be a fruitful new strategy for the management of AF. |
5,811 | Chaotic atrial tachycardia-related ventricular fibrillation in a 2-month-old baby with Wolff-Parkinson-White syndrome. | A 2-month-old baby was resuscitated from ventricular fibrillation attributed to a concurrent chaotic atrial tachycardia with Wolff-Parkinson-White syndrome. He underwent successful radiofrequency catheter ablation of an accessory pathway. Throughout the 4-year follow-up after the procedure, the boy remained free of any drugs, was in sinus rhythm without ventricular pre-excitation and his growth and development were normal. |
5,812 | Same morphology of ventricular premature complexes triggering repeated ventricular fibrillation. | Episodes ventricular fibrillation (VF) initiated by ventricular premature complexes (VPCs) of a single morphology have been reported. However, the characteristics of the VPCs over long periods of time are unknown.</AbstractText>To compare the morphologies and coupling intervals of VPCs that initiate episodes of VF that occur at different time periods.</AbstractText>The database of the follow-up of the International Classification of Diseases (ICD) unit was reviewed and patients having at least two spontaneous VF episodes with available recorded EGMs in unipolar and bipolar configuration were included in the study. The coupling interval and morphology of the initiating beat were analyzed.</AbstractText>Nine out of 300 patients with ICD had two or more spontaneous VF episodes. The time interval between episodes ranged from seconds (arrhythmic storm) to 3 years. The fibrillatory VPCs presented the same morphology in both recordings in all episodes of each patient. The coupling intervals of VPCs initiating VF were close for the episodes that occurred during a single arrhythmic storm and were more variable when the time intervals between episodes of VF were longer.</AbstractText>VPCs triggering VF that occur at different times in the same patient have similar morphologies suggesting similar sites of origin for the initial VPC of VF in each patient.</AbstractText> |
5,813 | A prospective 1-year study of changes in neuropsychological functioning after implantable cardioverter-defibrillator surgery. | The testing of the implantable cardioverter-defibrillator (ICD), through the induction of repeated episodes of ventricular fibrillation, has been associated with disturbances in cerebral activity and increased levels of cytoplasmic enzymes. However, the neuropsychological outcomes of cerebral changes and their quality-of-life implications are unknown.</AbstractText>Fifty-two ICD recipients completed standardized validated neuropsychological tests 1 to 3 days before ICD surgery and then 6 weeks, 6 months, and 12 months after surgery. They also completed psychometric tests measuring anxiety, depression, and quality of life. Between 31% and 39% of patients showed a significant neuropsychological impairment from their baseline function 6 weeks, 6 months, and 12 months after surgery. Ten percent of patients had late-onset deficits at 12 months only. Frequent areas of impairment were auditory and visual memory and attention. Neuropsychological impairment was not related to mood or quality of life at follow-up, although anxiety and depression predicted reduced quality of life.</AbstractText>ICD implantation is associated with neuropsychological impairment that dissipates for the majority of recipients after 12 months. Short-term memory function and attention are particularly vulnerable to changes in oxygen during ICD testing. Although anxiety and depression are prevalent, there is little evidence for the direct impact of mood on cognition, and deficits appear not to be associated with reduced quality of life. These results provide evidence for longitudinal outcomes of ICD surgery and have implications for patient rehabilitation and adjustment.</AbstractText> |
5,814 | Type 2 diabetes mellitus and the risk of sudden cardiac arrest in the community. | The reduction of mortality from sudden cardiac arrest (SCA) in the setting of coronary heart disease (CHD) remains a major challenge, especially among patients with type 2 diabetes. Diabetes is associated with an increased risk of SCA, at least in part, from an increased presence and extent of coronary atherosclerosis (macrovascular disease). Diabetes also is associated with microvascular disease and autonomic neuropathy; and, these non-coronary atherosclerotic pathophysiologic processes also have the potential to increase the risk of SCA. In this report, we review the absolute and relative risk of SCA associated with diabetes. We summarize recent evidence that suggests that the increase in risk in patients with diabetes is not specific for SCA, as diabetes also is associated with a similar increase in risk for non-SCA CHD death and non-fatal myocardial infarction. These data are consistent with prior observations that coronary atherosclerosis is a major contributor to the increased SCA risk associated with diabetes. We also present previously published and unpublished data that demonstrates that both clinically-recognized microvascular and autonomic neuropathy also are associated with the risk of SCA among treated patients with diabetes, after taking into account prior clinically-recognized heart disease and other risk factors for SCA. We then discuss how these data might inform research and clinical efforts to prevent SCA. Although the prediction of SCA in this "high" risk population is likely to remain a challenge, as it is in other "high" risk clinical populations, we suggest that current recommendations for the prevention of SCA in the community, related to both lifestyle prescriptions and risk factor reduction, are likely to reduce mortality from SCA among patients with diabetes. |
5,815 | Abnormal action potential duration restitution property in the right ventricular outflow tract in Brugada syndrome. | Although patients with Brugada syndrome (BS) are at risk of ventricular fibrillation (VF) and ensuing death, the action potential duration (APD) restitution properties of the right ventricular outflow tract (RVOT) in patients with BS remain undetermined.</AbstractText>Endocardial monophasic action potentials (MAPs) were obtained from 16 patients with BS and 17 control patients. MAPs were recorded from the RVOT in all patients. The MAP duration at 90% repolarization (MAPD(90)), effective refractory period (ERP), and maximum slope of the APD restitution curve were obtained. VF was induced with up to 3 extrastimuli from the RV apex or RVOT. There was no difference in MAPD(90) between the 2 groups, but the ERP was significantly shorter in patients with BS than in control patients (210.7+/-10.5 vs 223.8+/-13.4 ms, P=0.008). MAPD at the shortest diastolic interval was significantly shorter in patients with BS than in control patients (149.9+/-19.9 vs 179.8+/-13.7 ms, P<0.001). The maximum slope of the APD restitution curve was steeper in patients with BS than in control patients (2.90+/-1.29 vs 1.38+/-0.41, P<0.001).</AbstractText>The shorter ERP, shorter MAPD at the shortest diastolic interval and steeply sloped APD restitution curve in the RVOT appear to be related to the inducibility of VF in patients with BS.</AbstractText> |
5,816 | Strategies to reduce the risk of transvenous lead extraction: an example using a hybrid approach in a patient with a haemodialysis fistula. | Haemodialysis (HD) patients are at increased risk of vascular access complications with device therapy. We report a case of transvenous defibrillator lead extraction from the ipsilateral side as an HD fistula. The procedure was successfully performed using a hybrid approach, with extraction of the lead with a powered sheath, and surgical cut-down and closure of the subclavian vein defect. |
5,817 | Loss of biventricular pacing due to T-wave oversensing. | The benefits obtained with cardiac resynchronization therapy are directly related to the occurrence of continuous biventricular pacing. We report a case of intermittent loss of biventricular pacing due to ventricular oversensing that worsened the functional status of the patient. |
5,818 | Usefulness of statins in preventing atrial fibrillation in patients with permanent pacemaker: a systematic review. | Patients with permanent pacemakers (PM) are at high risk of developing atrial fibrillation (AF). Minimal ventricular pacing modalities have been demonstrated to reduce AF in such patients, although they are not suitable for patients with advanced atrioventricular conduction disease. Recent evidences suggest that 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (i.e. statins) may represent a new strategy to prevent AF in patients at risk. In this article, we sought to review data regarding the effectiveness of statin therapy in preventing AF patients with a PM. We reviewed all available studies that assessed the effect of statin therapy on the occurrence of AF in patients with PM, implanted due to sinus node dysfunction or atrioventricular conduction disease. Moreover, a random effect inverse variance-weighted meta-analysis was performed, by entering directly the logarithm of the hazard ratio (HR) of AF provided in the multiple Cox regression analyses from each study. Three studies were identified, including 552 patients, of whom 159 received statins. Follow-up ranged from 1 to 2.77 years. Two studies (one observational and one prospective randomized) included predominantly patients with sinus node dysfunction (70% and 91% of patient population, respectively) and, consistently, showed a beneficial effect of statins on the occurrence of AF. On the other hand, the study including predominantly patients with atrioventricular block (60% of patient population) failed to show a beneficial effect of statins on AF occurrence. The HR for AF occurrence for the cumulative data was found to be 0.43 (95% confidence interval: 0.28-0.67, P < 0.001). Statistical heterogeneity between included studies was not detected (chi(2) = 1.68, P = 0.43, I(2) = 0%), although significant clinical differences were found in terms of study design, patient populations, statins use and dosage and AF-monitoring capabilities. Statins may represent a novel treatment strategy to prevent the occurrence of AF in patients with PM, especially for those who had a PM implanted due to sinus node dysfunction. Basing on our findings, a randomized clinical trial with a proper design to evaluate the utility of statins in preventing AF in these patients is warranted. |
5,819 | Ischaemia-modified albumin predicts the outcome of cardiopulmonary resuscitation: An experimental study. | Ischaemia-modified albumin (IMA) has recently been shown to be an early and sensitive marker of ischaemia. It is generally accepted that cardiac arrest causes the most severe form of global ischaemia. The aim of the present study was to identify whether IMA is an independent predictor of return of spontaneous circulation (ROSC) in a swine model of cardiac arrest.</AbstractText>Ventricular fibrillation (VF) was induced in 30 piglets, which were left untreated for 8 min before attempting resuscitation with precordial compression, mechanical ventilation and electrical defibrillation. Electrical defibrillation was attempted after 10 min of VF. Blood samples for IMA determination were drawn at baseline, after 8 min of VF and before delivery of each shock. A binary logistic regression model was implemented for the prediction of animals achieving ROSC from data available before the first defibrillation attempt. Backward stepwise selection was used to extract the final model. Inclusion and exclusion significance levels were 0.1 and 0.05, respectively. Receiver operating characteristic curves were used to determine the diagnostic accuracy, sensitivity and specificity of the parameters and to obtain the appropriate cut-off points.</AbstractText>IMA exhibited 100% sensitivity and 93.8% specificity in defining the subgroup of animals that will achieve ROSC. This high-accuracy prediction had a very early onset (from eighth VF minute) and remained at the same level until the end of the experiment. When combining IMA and coronary perfusion pressure (CPP) measurements from the first CPR cycle in the form of the simple ratio IMA/CPP, a cut-off point of 7 could provide 100% sensitivity and specificity in distinguishing the animals that will achieve ROSC in the upcoming defibrillation attempts.</AbstractText>Until today, CPP has been found to be the only key determinant of successful resuscitation. Our study suggests that IMA can be a predictive index of ROSC even before the initiation of CPR.</AbstractText>Copyright 2010 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
5,820 | Circadian variation of late potentials in idiopathic ventricular fibrillation associated with J waves: insights into alternative pathophysiology and risk stratification. | The presence of J waves on ECGs is related to idiopathic ventricular fibrillation (VF).</AbstractText>The purpose of this study was to investigate the pathophysiology of J waves by assessing risk markers that reflect electrophysiologic abnormalities.</AbstractText>The study enrolled 22 idiopathic VF patients (17 men and 5 women; mean age 36 +/- 13 years). Patients were divided into two groups according to the presence or absence of J waves. The following risk stratifiers were assessed: late potentials (LPs; depolarization abnormality marker) for 24 hours using a newly developed signal-averaging system, and T-wave alternans and QT dispersion (repolarization abnormality markers). Frequency-domain heart rate variability (HRV), which reflects autonomic modulation, also was assessed. The results were compared to those of 30 control subjects with J waves and 30 with no J wave, matched for age and gender to the idiopathic VF patients.</AbstractText>J waves were present in 7 (32%) idiopathic VF patients. The incidence of LP in the idiopathic VF J-wave group was higher than in the idiopathic VF non-J-wave group (86% vs 27%, P = .02). In contrast, repolarization abnormality markers did not differ between the two groups. In the idiopathic VF J-wave group, dynamic changes in LP parameters (fQRS, RMS(40), LAS(40)) were observed and were pronounced at nighttime; this was not the case in the idiopathic VF non-J-wave group and the control J-wave group. High-frequency components (vagal tone index) on frequency-domain HRV analysis were associated with J waves in idiopathic VF patients (P < .05).</AbstractText>Idiopathic VF patients with J waves had a high incidence of LP showing circadian variation with night ascendancy. J waves may be more closely associated with depolarization abnormality and autonomic modulation than with repolarization abnormality.</AbstractText>Copyright 2010 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
5,821 | Electrophysiological characteristics of the Marshall bundle in humans. | Marshall bundles (MBs) are the muscle bundles within the ligament of Marshall.</AbstractText>This trial sought to the electrophysiological characteristics of the MB and the anatomical connections between MB and left atrium (LA) in patients with persistent atrial fibrillation (AF).</AbstractText>We enrolled 72 patients (male:female 59:13, age 59.9 +/- 9.4 years) who underwent MB mapping and ablation for AF. MB mapping was done via an endocardial or epicardial approach during sinus rhythm and AF.</AbstractText>Recordings were successful in 64 of 72 patients (89%). A single connection was noted in 11 of 64 patients between the MB and the coronary sinus (CS) muscle sleeves. The MB recordings showed distinct MB potentials with a proximal-to-distal activation pattern during sinus rhythm. During AF, organized passive activations and dissociated slow MB ectopic activities were commonly observed in this type of connection. Double connections to both CS and LA around left pulmonary veins were noted in 23 of 64 patients (36%). After the ablation of the distal connection, MB recording showed typical double potentials as in single connection. Multiple connections were noted in 30 of 64 patients (47%). During sinus rhythm, the earliest activation was in the middle of the MB. The activation patterns were irregular and variable in each patient. During AF, rapid and fractionated complex activations were noted in all patients of this group.</AbstractText>We documented 3 different types of MB-LA connections. Rapid and fractionated activations were most commonly observed in the MB that had multiple LA connections.</AbstractText>Copyright (c) 2010. Published by Elsevier Inc.</CopyrightInformation> |
5,822 | Epicardial Catheter Ablation of Atrial Fibrillation. | Atrial fibrillation (AF) can cause significant symptoms despite control of ventricular rate, and for some patients a rhythm-control strategy is more appropriate. Because antiarrhythmic drugs have limited efficacy for treating AF and can cause significant side effects, nonpharmacologic therapy has found a growing role in the treatment of this arrhythmia. While endocardial catheter ablation has shown superior results over drug therapy, long-term clinical outcomes are still disappointing, especially for persistent AF. This article discusses percutaneous epicardial catheter ablation, the rationale for using this approach to treat AF, anatomy relevant to the approach, challenges in performing such procedures, and finally, the potential future directions in this promising new field. |
5,823 | Medtentia double helix mitral annuloplasty system evaluated in a porcine experimental model. | : To further develop and improve minimally invasive surgical procedures, dedicated appropriate surgical devices are mandatory. In this study, the safety and feasibility of implanting the novel Medtentia double helix mitral annuloplasty ring, which uses the key-ring principle to potentially allow faster and sutureless implantation, was assessed using both minimally invasive and conventional surgical techniques. Because of ethical concerns, a human compatible porcine experimental model of mitral valve surgery was used.</AbstractText>: Twelve 50-kg pigs were allocated to implantation of the Medtentia double helix annuloplasty ring using conventional midline sternotomy including cardioplegic arrest or a minimally invasive approach using peripheral cannulation and left ventricular fibrillation. Ten weeks after surgery, echocardiography was performed to assess mitral valve function. Animals were then killed, and gross mitral valve anatomy was examined ex vivo.</AbstractText>: All animals survived 10 weeks without developing mitral regurgitation, structural leaflet damage, ring dehiscence, or endocarditis. In the minimally invasive compared with the midline sternotomy group (mean ± SD), significantly reduced recovery time (80 ± 16 vs. 327 ± 23 minutes, P < 0.01) and a tendency toward increased operating time (199 ± 33 vs. 168 ± 15 minutes, P > 0.05) and cardiopulmonary bypass time (98 ± 12 vs. 91 ± 11 minutes, P > 0.05) were observed.</AbstractText>: By using a both minimally invasive and conventional midline sternotomy implantation techniques, the Medtentia double helix annuloplasty ring showed no mitral valve dysfunction or tissue damage 10 weeks postoperatively.</AbstractText> |
5,824 | Dilated cardiomyopathy and role of antithrombotic therapy. | There is no consensus as to whether anticoagulation has a favorable risk:benefit in reducing thromboembolic events in patients with heart failure (HF) secondary to dilated cardiomyopathy who do not suffer from atrial fibrillation or primary valvular disease.</AbstractText>The literature reviewed on this topic included most recent and ongoing studies that assessed the use of anticoagulation for this population. Several large retrospective studies showed an increased risk of thromboembolic events among patients with depressed left ventricular function. The relative risk of stroke in individuals with HF from all causes was found to be 4.1 for men and 2.8 for women, but confounding comorbidities (such as atrial fibrillation and coronary artery disease) were commonly present. Currently, there are no randomized prospective trials to guide the use of antithrombotics for these patients, and the risk of bleeding secondary to anticoagulation has limited the use of oral anticoagulants for prevention of thrombosis. Among patients with HF, increasing age directly correlates with both major bleeding and thromboembolic events, with a 46% relative risk of bleeding for each 10-year increase in age older than 40 years.</AbstractText>To date, there is no agreement on appropriate antithrombotic treatment (if any) for primary thromboembolism prophylaxis in patients with dilated cardiomyopathy with sinus rhythm. In recent years, several promising prospective trials were terminated prematurely due to inadequate enrollment. The Warfarin Aspirin-Reduced Cardiac Ejection Fraction trial may provide evidence regarding the use of anticoagulation for patients with decreased myocardial function.</AbstractText> |
5,825 | Noncompaction of ventricular myocardium associated with hypertrophic cardiomyopathy and polycystic kidney disease. | Noncompaction of ventricular myocardium (NVM), a relatively new diagnostic entity, is described as an arrest in the process of compaction of myocardial fibers, which results in a prominent trabecular network and deep intertrabecular recesses. Its coexistence with other cardiac anomalies like hypertrophic obstructive cardiomyopathy (HOCM) or polycystic kidney disease (PKD) had been reported in the past. We report the first case with all 3 different inherent conditions (NVM, HOCM, and PKD) manifesting in 1 patient. A 37-year-old man was referred for evaluation of a heart murmur. His medical history was positive for paroxysmal atrial fibrillation. Physical examination revealed a grade 3/6 systolic murmur loudest along the left sternal border accentuating on Valsalva maneuver. Echocardiography revealed HOCM. Cardiac magnetic resonance confirmed the presence of HOCM with the incidental finding of NVM and PKD. This case raises the possibility of genetic mutation common to these 3 clinical entities or 2 different gene mutations existing in the same individual. |
5,826 | Ventricular fibrillation during anesthesia in a Wenchuan earthquake victim with crush syndrome. | We cared for a victim of the Wenchuan earthquake who was rescued after being buried in rubble for 52 hours. On admission to the hospital, the patient had severe hyperkalemic acidosis and necrosis of both legs, requiring bilateral amputation. In the operating room, the patient developed ventricular fibrillation. The patient was resuscitated and recovered without significant systemic injury. We review the diagnosis and treatment of crush syndrome, which occurs in many victims of natural disasters. |
5,827 | Cyanide poisoning and cardiac disorders: 161 cases. | Inhalation of hydrogen cyanide from smoke in structural fires is common, but cardiovascular function in these patients is poorly documented.</AbstractText>The objective was to study the cardiac complications of cyanide poisoning in patients who received early administration of a cyanide antidote, hydroxocobalamin (Cyanokit; Merck KGaA, Darmstadt, Germany [in the United States, marketed by Meridian Medical Technologies, Bristol, TN]).</AbstractText>The medical records of 161 fire survivors with suspected or confirmed cyanide poisoning were reviewed in an open, multicenter, retrospective review of cases from the Emergency Medical Assistance Unit (Service d'Aide Médical d'Urgence) in France.</AbstractText>Cardiac arrest (61/161, 58 asystole, 3 ventricular fibrillation), cardiac rhythm disorders (57/161, 56 supraventricular tachycardia), repolarization disorders (12/161), and intracardiac conduction disorders (5/161) were observed. Of the total 161 patients studied, 26 displayed no cardiac disorder. All patients were given an initial dose of 5 g of hydroxocobalamin. Non-responders received a second dose of 5 g of hydroxocobalamin. Of the patients initially in cardiac arrest, 30 died at the scene, 24 died in hospital, and 5 survived without cardiovascular sequelae. Cardiac disorders improved with increasing doses of hydroxocobalamin, and higher doses of the antidote seem to be associated with a superior outcome in patients with initial cardiac arrest.</AbstractText>Cardiac complications are common in cyanide poisoning in fire survivors.</AbstractText>Copyright (c) 2010 Elsevier Inc. All rights reserved.</CopyrightInformation> |
5,828 | Differences in effects of electrical therapy type for ventricular arrhythmias on mortality in implantable cardioverter-defibrillator patients. | Implantable cardioverter-defibrillator (ICD) shocks have been associated with an increased risk of death. It is unknown whether this is due to the ventricular arrhythmia (VA) or shocks and whether antitachycardia pacing (ATP) termination can reduce this risk.</AbstractText>The purpose of this study was to determine whether mortality in ICD patients is influenced by the type of therapy (shocks of ATP) delivered.</AbstractText>Cox models evaluated effects of baseline characteristics, ventricular tachycardia (VT; <188 bpm), fast VT (FVT; 188-250 bpm), ventricular fibrillation (VF; >250 bpm), and therapy type (shocks or ATP) on mortality among 2135 patients in four trials of ATP to reduce shocks.</AbstractText>Over 10.8 +/- 3.3 months, 24.3% patients received appropriate shocks (50.6%) or ATP only (49.4%), and 6.6% died. Mortality predictors were age (hazard ratio 1.07, 95% confidence interval 1.04-1.08, P <.0001), New York Heart Association class III/IV (3.50 [2.27-5.41]; P <.0001), coronary disease (3.08 [1.31-7.25]; P = .01), and cumulative VA (VT + FVT + VF) episodes shocked (1.20 [1.13, 1.29]; P <.0001). Beta-blockers (0.65, 0.46-0.92; P <.0001) and remote myocardial infarction (0.53, [0.38-0.76] P = .0004) predicted reduced risk. Since 92% of VT and all VF received a single therapy type (ATP and shocks, respectively), the effect of therapy on episode risk could not be established. For FVT (32% shocked, 68% ATP), episode and therapy effects could be uncoupled; ATP-terminated FVT did not increase episode mortality risk, whereas shocked FVT increased risk by 32%. Survival rates were highest among patients with no VA (93.8%) of ATP-only (94.7%) and lowest for shocked patients (88.4%). Monthly episode rates were 80% higher among shocked versus ATP-only patients.</AbstractText>Shocked VA episodes are associated with increased mortality risk. Shocked patients have substantially higher VA episode burden and poorer survival compared with ATP-only-treated patients.</AbstractText>Copyright 2010 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
5,829 | Loss of pace capture on the ablation line: a new marker for complete radiofrequency lesions to achieve pulmonary vein isolation. | Catheter ablation procedures for atrial fibrillation (AF) often involve circumferential antral isolation of pulmonary veins (PV). Inability to reliably identify conduction gaps on the ablation line necessitates placing additional lesions within the intended lesion set.</AbstractText>This pilot study investigated the relationship between loss of pace capture directly along the ablation line and electrogram criteria for PV isolation (PVI).</AbstractText>Using a 3-dimensional anatomic mapping system and irrigated-tip radiofrequency (RF) ablation catheter, lesions were placed in the PV antra to encircle ipsilateral vein pairs until pace capture at 10 mA/2 ms no longer occurred along the line. During ablation, a circular mapping catheter was placed in an ipsilateral PV, but the electrograms were not revealed until loss-of-pace capture. The procedural end point was PVI (entrance and exit block).</AbstractText>Thirty patients (57 +/- 12 years; 15 male [50%]) undergoing PVI in 2 centers (3 primary operators) were included (left atrial diameter 40 +/- 4 mm, left ventricular ejection fraction 60 +/- 7%). All patients reached the end points of complete PVI and loss of pace capture. When PV electrograms were revealed after loss of pace capture along the line, PVI was present in 57 of 60 (95%) vein pairs. In the remaining 3 of 60 (5%) PV pairs, further RF applications achieved PVI. The procedure duration was 237 +/- 46 minutes, with a fluoroscopy time of 23 +/- 9 minutes. Analysis of the blinded PV electrograms revealed that even after PVI was achieved, additional sites of pace capture were present on the ablation line in 30 of 60 (50%) of the PV pairs; 10 +/- 4 additional RF lesions were necessary to fully achieve loss of pace capture. After ablation, the electrogram amplitude was lower at unexcitable sites (0.25 +/- 0.15 mV vs. 0.42 +/- 0.32 mV, P < .001), but there was substantial overlap with pace capture sites, suggesting that electrogram amplitude lacks specificity for identifying pace capture sites.</AbstractText>Complete loss of pace capture directly along the circumferential ablation line correlates with entrance block in 95% of vein pairs and can be achieved without circular mapping catheter guidance. Thus, pace capture along the ablation line can be used to identify conduction gaps. Interestingly, more RF ablation energy was required to achieve loss of pace capture along the ablation line than for entrance block into PVs. Further study is warranted to determine whether this method results in more durable ablation lesions that reduce recurrence of AF.</AbstractText>Copyright 2010 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
5,830 | Prognostic importance of atrial fibrillation in implantable cardioverter-defibrillator patients. | This study aimed to assess the prevalence of different types of atrial fibrillation (AF) and their prognostic importance in implantable cardioverter-defibrillator (ICD) patients.</AbstractText>The prevalence of AF has taken epidemic proportions in the population with cardiovascular disease. The prognostic importance of different types of AF in ICD patients remains unclear.</AbstractText>Data on 913 consecutive patients (79% men, mean age 62 + or - 13 years) receiving an ICD at the Leiden University Medical Center were prospectively collected. Among other characteristics, the existence and type of AF (paroxysmal, persistent, or permanent) were assessed at implantation. During follow-up, the occurrence of appropriate or inappropriate device therapy as well as mortality was noted.</AbstractText>At implantation, 73% of patients had no history of AF, 9% had a history of paroxysmal AF, 7% had a history of persistent AF, and 11% had permanent AF. During 833 + or - 394 days of follow-up, 117 (13%) patients died, 228 (25%) patients experienced appropriate device discharge, and 139 (15%) patients received inappropriate shocks. Patients with permanent AF exhibited more than double the risk of mortality, ventricular arrhythmias triggering device discharge, and inappropriate device therapy. Patients with paroxysmal or persistent AF did not show a significant increased risk of mortality or appropriate device therapy but demonstrated almost 3 times the risk of inappropriate device therapy.</AbstractText>In the population currently receiving ICD treatment outside the setting of clinical trials, a large portion has either a history of AF or permanent AF. Both types of AF have prognostic implications for mortality and appropriate as well as inappropriate device discharge.</AbstractText>Copyright 2010 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
5,831 | High-frequency ventricular ectopy can increase sympathetic neural activity in humans. | Sudden cardiac death is usually caused by ventricular arrhythmias and in many cases, is preceded by frequent ventricular ectopy. It is known that ectopic beats cause transient increases in sympathetic nerve activity (SNA).</AbstractText>Because high SNA is known to be arrhythmogenic, we hypothesized that high rates of ectopy increase SNA, thereby creating a milieu that favors development of ventricular tachycardia and/or fibrillation.</AbstractText>This study measured muscle SNA, coronary sinus catecholamine, and arterial pressure during graded rates of ventricular ectopy (from 4:1 to 1:1, sinus to ectopic beat ratio) in a total of 21 patients referred for electrophysiologic testing.</AbstractText>Both muscle SNA and coronary sinus norepinephrine increased significantly with increased ectopy frequency (P < .05). Moreover, the change in muscle SNA correlated significantly with the change in coronary sinus norepinephrine levels (r = .72, P < .001).</AbstractText>These data demonstrate that sympathoexcitation evoked by high rates of ventricular ectopy can contribute to a state of elevated SNA both in peripheral tissues and within the heart. This altered autonomic state may contribute to an increased susceptibility to life-threatening tachyarrhythmias in patients with high rates of ectopy.</AbstractText>Copyright 2010 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
5,832 | Causes of ventricular oversensing in implantable cardioverter-defibrillators: implications for diagnosis of lead fracture. | Implantable cardioverter-defibrillator (ICD) ventricular oversensing may result in inappropriate therapy, which may be triggered by lead/connection issues that require surgical revision or physiologic oversensing that may be resolved with reprogramming. The sensing integrity counter (SIC) is an oversensing diagnostic that increments for very rapid ventricular intervals < or =130 ms.</AbstractText>The purpose of this study was to determine the causes of a high SIC and the ability of additional diagnostics to differentiate lead/connection issues from other causes of oversensing for patients with normal impedance.</AbstractText>Frequent SICs were identified in patients during routine follow-up visits. To diagnose the cause of oversensing, patients wore a modified 24-hour digital Holter monitor that recorded ECG, ventricular electrogram, and the ICD Marker Channel (Medtronic). Recordings were reviewed to determine the causes of oversensing. Patients with confirmed oversensing and adequate data were analyzed. The number of SICs per day and the presence of a nonsustained tachycardia (NST) episode with ventricular mean cycle length <220 ms were retrieved from stored ICD data.</AbstractText>Forty-eight patients had a median of 13 SICs/day. Presumed lead/connection issues occurred in 23% of patients, whereas physiologic oversensing occurred in 77% of patients. A rapid NST was recorded more commonly in patients with lead/connection issues than in those without (9/11 vs 1/37; P < .0001).</AbstractText>Oversensing resulting in frequent, very short intervals typically are caused by either lead/connection issues or physiologic signals. The additional finding of rapid NSTs usually indicates a lead/connection issue, even in the absence of impedance abnormalities.</AbstractText>Copyright 2010 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
5,833 | Deglutition syncope associated with ventricular asystole in a patient with permanent atrial fibrillation. | Deglutition syncope is a situational syncope that is diagnosed only by a detailed history. We report deglutition syncope in a 62-year-old man, who had permanent atrial fibrillation. The patient had no structural or functional abnormalities of the esophagus. During syncopal attacks, his electrocardiography showed ventricular asystole that was sustained for 12 seconds. The patient was successfully treated by implantation of a permanent pacemaker. |
5,834 | A hypokalemic muscular weakness after licorice ingestion: a case report. | A 21-year-old male presented to the emergency department with the complaint of muscle weakness. The patient had used a powderized over-the-counter product named 'Tekumut' for 2 weeks to quit smoking. The granulated product was studied and determined to contain 'licorice' containing glycyrrhizic acid.Licorice (a plant which contain glycyrrhizic acid) -induced hypokalemia usually has a mild progression. However, it may cause a critical failure in physical action by means of weakness followed by paralysis and may cause rhabdomyolysis or ventricular fibrillation, leading to death, when left untreated.This report has presented the first case with hypocalemia due to licorice consumption in granulated form from Turkey. In addition, the report has aimed to emphasize the importance of obtaining the detailed history of a patient in diagnosis. |
5,835 | Eosinophilic myocarditis mimicking acute coronary syndrome secondary to idiopathic hypereosinophilic syndrome: a case report. | Eosinophilic myocarditis is a rare form of myocarditis. It is characterized pathologically by diffuse or focal myocardial inflammation with eosinophilic infiltration, often in association with peripheral blood eosinophilia. We report a case of eosinophilic myocarditis secondary to hypereosinophilic syndrome.</AbstractText>A 74-year-old Caucasian woman with a history of asthma, paroxysmal atrial fibrillation, stroke and coronary artery disease presented to the emergency department of our hospital with chest pain. Evaluations revealed that she had peripheral blood eosinophilia and elevated cardiac enzymes. Electrocardiographic findings were nonspecific. Her electrocardiographic finding and elevated cardiac enzymes pointed to a non-ST-elevated myocardial infarction. Echocardiogram showed a severe decrease in the left ventricular systolic function. Coronary angiogram showed nonobstructive coronary artery disease. She then underwent cardiac magnetic resonance imaging, which showed neither infiltrative myocardial diseases nor any evidence of infarction. This was followed by an endomyocardial biopsy which was consistent with eosinophilic myocarditis. Hematologic workup regarding her eosinophilia was consistent with hypereosinophilic syndrome. After being started on steroid therapy, her peripheral eosinophilia resolved and her symptoms improved. Her left ventricular ejection fraction, however, did not improve.</AbstractText>Eosinophilic myocarditis can present like an acute myocardial infarction and should be considered in the differential diagnosis of acute coronary syndrome in patients with a history of allergy, asthma or acute reduction of the left ventricular function with or without peripheral eosinophilia.</AbstractText> |
5,836 | Canine atrial fibrillation. | Atrial fibrillation (AF) is the most commonly diagnosed supraventricular tachyarrhythmia in dogs. It typically develops when atrial enlargement occurs secondary to underlying cardiovascular disease. Electrocardiographically, AF is characterized by disorganized atrial electrical activity resulting in an absence of P waves and a rapid, irregular ventricular rate. The hemodynamic consequences of AF include decreased cardiac output and the development of clinical signs of heart failure. Therapeutic management focuses on controlling ventricular rate or restoring and maintaining sinus rhythm using antiarrhythmic medication and, in some cases, biphasic transthoracic electrical cardioversion. The prognosis varies and is especially guarded in the presence of significant underlying cardiac disease, such as dilated cardiomyopathy. |
5,837 | New developments in atrial antiarrhythmic drug therapy. | Atrial fibrillation (AF) is a growing clinical problem associated with increased morbidity and mortality. Currently available antiarrhythmic drugs (AADs), although highly effective in acute cardioversion of paroxysmal AF, are generally only moderately successful in long-term maintenance of sinus rhythm. The use of AADs is often associated with an increased risk of ventricular proarrhythmia, extracardiac toxicity, and exacerbation of concomitant diseases such as heart failure. AF is commonly associated with intracardiac and extracardiac disease, which can modulate the efficacy and safety of AAD therapy. In light of the multifactorial intracardiac and extracardiac causes of AF generation, current development of anti-AF agents is focused on modulation of ion channel activity as well as on upstream therapies that reduce structural substrates. The available data indicate that multiple ion channel blockers exhibiting potent inhibition of peak I(Na) with relatively rapid unbinding kinetics, as well as inhibition of late I(Na) and I(Kr), may be preferable for the management of AF when considering both safety and efficacy. |
5,838 | Influence of co-existing atrial fibrillation on the efficacy of atorvastatin treatment in patients with dilated cardiomyopathy: a pilot study. | The aim of the study was to assess the influence of co-existing atrial fibrillation (AF) on inflammatory condition factors, left ventricular function, clinical course and the efficacy of statin treatment of congestive heart failure in the course of dilated cardiomyopathy (DCM).</AbstractText>In a prospective, randomized, open-label study, 69 patients with DCM and left ventricular ejection fraction (LVEF) < or =40% were divided into two groups, with and without AF, who were treated according to the recommended standards. 68% of patients from the group with AF and 59% of patients from the group without AF were administered atorvastatin 40 mg daily for 8 weeks and 10 mg for next 4 months. Clinical examination with the assessment of body mass index (BMI) and waist size were followed by routine laboratory tests, measurement of concentration of tumor necrosis factor (TNF-alpha), interleukin-6 (IL-6), and IL-10 in blood plasma, N-terminal pro-brain natriuretic peptide (NT-proBNP) concentration in blood serum, echocardiographic examination, and the assessment of exercise capacity in 6-minute walk test (6-MWT). After six months, morbidity rate and the number of heart failure hospitalizations were also observed.</AbstractText>In the whole population of patients, a significantly higher concentration of NT-proBNP was observed in the AF group (2669 +/- 2192 vs 1540 +/- 1067, p = 0.02). After statin treatment, in patients with DCM and co-existing AF, higher values of NT-proBNP and IL-6 were observed compared to non-AF patients (1530 +/- 1054 vs 1006 +/- 1195, p = 0.04 and (14.16 +/- 13.40 vs 6.74 +/- 5.45, p = 0.02, respectively).</AbstractText>In patients with DCM and co-existing AF, a weaker effect of atorvastatin concerning the reduction of IL-6 and NT-proBNP concentration was observed than in patients without atrial fibrillation.</AbstractText> |
5,839 | A randomized comparison of cardiocerebral and cardiopulmonary resuscitation using a swine model of prolonged ventricular fibrillation. | Cardiocerebral resuscitation (CCR) is reportedly superior to cardiopulmonary resuscitation (CPR) for primary cardiac arrest in the prehospital setting. This study was done using a swine model of prolonged ventricular fibrillation (VF) to quantify the effect of the emergency medical services component of CCR with intraosseous access (CCR-IO) compared with standard CPR with intravenous access (CPR-IV) as it is typically performed during out-of-hospital cardiac arrest (OHCA) resuscitation in a prospective randomized fashion.</AbstractText>Fifty-three animals were instrumented under anesthesia and VF was electrically induced. After 10 min of untreated VF, baseline characteristics were recorded, and animals were block randomized to one of two resuscitation schemes. The controls had mechanical chest compressions at 100/min with ventilations at a ratio of 30:2. Consistent with clinical practice, two 30-s pauses in chest compressions occurred to simulate attempts to accomplish endotracheal intubation at minutes 1 and 3 of CPR and successful IV access was simulated to occur three additional minutes after endotracheal intubation. The CCR group had continuous uninterrupted mechanical chest compressions at 100/min. No active ventilations were provided. A tibial IO needle was placed in real time for vascular access. Both groups received epinephrine (0.1 mg/kg) as soon as access became available followed by 2.5 min of chest compressions before the first 120 J rescue shock attempt. After successful rescue shock, standardized post-resuscitative care was provided to a 20-min endpoint. Failed rescue shock was followed by continued chest compressions with positive pressure ventilation in both groups, repeat doses of epinephrine (0.01 mg/kg) every 3 min, and rescue shock every minute as long as a shockable rhythm persisted. Group comparisons were assessed using descriptive statistics. Proportions with 95% confidence intervals were calculated for VF termination, ROSC, and survival.</AbstractText>Baseline characteristics and chemistries between the two groups at VF induction and after 10 min of non-treatment were mathematically the same. The proportions of VF termination (0.50 vs. 0.82), ROSC (0.30 vs. 0.59), and 20-min survival (0.19 vs. 0.40) all strongly favored the CCR-IO group.</AbstractText>In this swine model of witnessed VF arrest with no bystander-initiated resuscitation, CCR-IO resulted in substantial improvement in all three outcomes relative to typical emergency medical services provided CPR-IV.</AbstractText>Copyright 2010 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
5,840 | Protective effects of estrogen against reperfusion arrhythmias following severe myocardial ischemia in rats. | Female sex hormones may have protective effects against arrhythmias, including reperfusion arrhythmias (RAs), but the mechanisms are still not completely known.</AbstractText>Serial changes in rat hearts (rhythm, apoptosis and the its infuencing factors; cardiac vinculin mRNA expression and connexin43 (Cx43) dephosphorylation) were examined during periods of ischemia-reperfusion with and without estrogen treatment. After reperfusion, although the incidence of arrhythmias became higher in both the vehicle-group and estrogen-group, compared with the ischemia period, estrogen prevented reperfusion-induced upregulation of the incidence of arrhythmias, especially ventricular premature beats (VPB) and ventricular tachycardia (VT). The duration of VT and fibrillation, and the number of VPB and VT, were all significantly decreased in the estrogen-group. The expression of cardiac vinculin mRNA decreased significantly in the vehicle-group but not in the estrogen-group. Cx43 dephosphorylation and myocyte apoptosis increased in both groups, but the values for the estrogen-group were all markedly lower than those for the vehicle-group. A selective estrogen receptor (ER) beta agonist prevented reperfusion-induced upregulation of the incidence of both VPB and VT significantly; a selective ERalpha agonist had no significant influence.</AbstractText>Estrogen can protect the heart against RAs, at least in part, mediated through gap junctions. Upregulation of ERbeta but not ERalpha mediated most of the estrogen-induced cardioprotection against RA.</AbstractText> |
5,841 | Pediatric out-of-hospital cardiac arrest in Korea: A nationwide population-based study. | Our objective was to describe the incidence and demographics of pediatric out-of-hospital cardiac arrest (OHCA) in Korea.</AbstractText>We identified non-traumatic OHCA patients aged less than 20 years from a Korean nationwide OHCA registry (2006-2007). Data from emergency medical service (EMS) run-sheets and hospital records were reviewed. We excluded cases with unknown hospital outcomes. Patient characteristics, treatment by EMS, and outcomes were compared by age groups: infant (<1 year), children (1-11 years), and adolescents (12-19 years).</AbstractText>A total of 971 patients including infants (n=299, 30.8%), children (n=305, 31.4%), and adolescents (n=367, 37.8%) met inclusion criteria. The incidence of pediatric OHCA was 4.2 per 100,000 person-years (67.1 in infants, 2.5 in children, and 3.5 in adolescents). The rate of cardiopulmonary resuscitation administered was 82.1% (infants 80.6%, children 82.0%, and adolescent 83.4%). The rate of applying automated external defibrillators and advanced airway management (endotracheal intubation or laryngeal mask airway), was only 4.1% and 2.5%, respectively. 7.4% showed ventricular fibrillation (VF) or pulseless ventricular tachycardia (VT) in the initial ECG. Survival to hospital discharge for all pediatric OHCA was 4.9% (2.9% for infants, 4.7% for children, and 7.2% of adolescents). For EMS-treated pediatric OHCA or patients with VF or pulseless VT, the rate was 5.0% and 31.6%, respectively.</AbstractText>Incidence and hospital outcomes in pediatric OHCA in Korea were comparable to other population-based nationwide reports.</AbstractText>Copyright 2009 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
5,842 | The E-wave delayed relaxation pattern to LV pressure contour relation: model-based prediction with in vivo validation. | The transmitral Doppler E-wave "delayed relaxation" (DR) pattern is an established sign of diastolic dysfunction (DD). Furthermore, chambers exhibiting a DR filling pattern are also expected to have a prolonged time-constant of isovolumic relaxation (tau). The simultaneous observation of a DR pattern and normal tau in the same heart is not uncommon, however. The simultaneous hemodynamic equivalent of the DR pattern has not been proposed. To determine the feature of the left ventricular (LV) pressure contour during the E-wave that is causally related to its DR pattern we applied kinematic and fluid mechanics based arguments to derive the pressure recovery ratio (PRR). The PRR is dimensionless and is defined by the left ventricular pressure difference between diastasis and minimum pressure, normalized to the pressure difference between a fiducial diastolic filling pressure and minimum pressure [PRR=(P(Diastasis)-P(Min))/(P(Fiducial)-P(Min))]. We analyzed 354 cardiac cycles from 40 normal sinus rhythm (NSR) subjects and 113 beats from nine atrial fibrillation (AF) subjects from our database of simultaneous transmitral flow-micromanometric LV pressure recordings. The fiducial pressure is defined by the end diastolic pressure in NSR and by the pressure at dP/dt(MIN) in the setting of AF. Consistent with derivation, PRR was linearly related to a DR pattern related, model-based relaxation parameter (R(2) = 0.77, 0.83 in NSR and AF, respectively). Furthermore, the PRR successfully differentiated subjects with a DR pattern from subjects with partial DR or normal E-wave pattern (p < 0.05). We conclude that the PRR may differentiate between subjects having a DR pattern and subjects with normal E-waves, even when tau cannot. |
5,843 | Left main coronary artery occlusion after percutaneous aortic valve implantation. | Left main coronary artery occlusion occurred immediately after transfemoral aortic valve implantation in an 87-year-old woman, which resulted in ventricular fibrillation and hemodynamic collapse. This life-threatening complication was promptly diagnosed with transesophageal echocardiography, which showed the disappearance of diastolic left main coronary artery jet flow and was confirmed with aortic root angiography. After prompt defibrillation, hemodynamic support was obtained with intra-aortic balloon pump and inotropic drugs. Functional recovery and survival were achieved with coronary stenting. This report highlights the importance of an integrated team approach of highly skilled specialists for these novel interventions. |
5,844 | [Effects of hypertension state induced by norepinephrine on liver in a swine model of cardiopulmonary resuscitation]. | To study the effects of norepinephrine (NE)-induced hypertension (HT) on hepatic function and pathology after restoration of spontaneous circulation (ROSC) by cardiopulmonary resuscitation (CPR) in swine.</AbstractText>After 4 minutes of induced ventricular fibrillation (VF), standard CPR was carried out, and then the NE was pumped after ROSC. The survivors were then divided into two groups by the random digits table. In the HT group (n=5) the mean arterial pressure (MAP) was maintained at 130% of the baseline (MAP before VF), and in the normal pressure (NP) group (n=5) the MAP was maintained at the baseline level. At the same time, the animals of two groups received normal saline at the speed of 10 ml * kg(-1) * h(-1). Hemodynamic status was monitored and aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) were measured in blood samples obtained at baseline and at 10 minutes, 2 hours and 4 hours after ROSC. At 24 hours after ROSC, the animals were killed and the liver was removed to determine Na(+)-K(+)-ATPase and Ca(2+)-ATPase activities and pathological changes under light and electron microscopy.</AbstractText>The heart rate (HR), MAP, cardiac output (CO) and coronary perfusion pressure (CPP) were obviously higher, while the oxygen extraction ratio was lower in the HT group than in the NP group. Compared with NP group, AST in the HT group was lower at ROSC 2 hours, 4 hours [ROSC 2 hours: (110.5+/-12.1) U/L vs. (141.8+/-8.1) U/L; ROSC 4 hours: (118.2+/-14.1) U/L vs. (175.0+/-14.3) U/L, both P<0.05], LDH was lower at ROSC 4 hours [(18.1+/-1.9) micromol * s(-1) * L(-1) vs. (20.7+/-1.9) micromol * s(-1) * L(-1), P<0.05], but ALT showed no significant difference between two groups after ROSC. ATPase activity in the HT group [Na(+)-K(+)-ATPase: (2.054+/-0.716) U, Ca(2+)-ATPase: (1.889+/-0.450) U] was a little lower than that of the NP group [Na(+)-K(+)-ATPase: (3.274+/-0.710) U, Ca(2+)-ATPase: (2.746+/-0.778) U], but without statistical significance (both P>0.05). Compared with the NP group, there was less cellular edema, necrosis or inflammatory cells infiltration, and less damaged mitochondria in HT group.</AbstractText>These data suggest that HT induced by NE helps to maintain stable hemodynamic status and oxygen metabolism, and may protect the liver in terms of function and cellular injury after CPR.</AbstractText> |
5,845 | [The influence of hypothermia therapy on enzymology and pathology of lung after cardiac arrest]. | To study the effect of hypothermia on pro-inflammatory mediators in serum, the enzymology and pathology of lung tissue.</AbstractText>Ventricular fibrillation for 4 minutes was induced in 10 domestic pigs. Standard cardiopulmonary resuscitation was given to them. They were then divided into two groups according to the random table after restoration of spontaneous circulation (ROSC): low temperature group (n=5): pigs were given an infusion 30 ml/kg of 4 centigrade normal saline (NS) at an infusion rate of 1.33 ml * kg(-1) * min(-1), started after ROSC for 22 minutes, then 10 ml * kg(-1) * h(-1) for 4 hours; ambient temperature group (n=5) received the same infusion of NS in room temperature. Hemodynamic parameters were observed, blood samples were collected to measure tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) in serum before ventricular fibrillation and 10 minutes, 2 hours, 4 hours after ROSC. Na(+)-K(+)-ATPase of lung tissue was determined 24 hours after ROSC, and the pathology and ultrastructure of the lung were studied.</AbstractText>There was no significant difference in the hemodynamic parameters, except the temperature, between low temperature and ambient temperature groups. TNF-alpha contents at 10 minutes, 2 hours, 4 hours after ROSC in low temperature group were (15.55+/-1.65), (17.06+/-0.86), (12.52+/-1.82) ng/L, and the IL-6 contents were (173.80+/-15.01), (184.09+/-13.44), (73.17+/-6.95) ng/L, while the TNF-alpha contents at 10 minutes, 2 hours, 4 hours after ROSC in ambient temperature group were (20.09+/-1.32), (26.18+/-1.16), (29.18+/-1.20) ng/L, and the IL-6 contents were (176.92+/-16.68), (239.17+/-13.18), (405.48+/-55.49) ng/L. The pro-inflammatory mediators in low temperature group were reduced significantly (P<0.05 or P<0.01). Low temperature could significantly reduce the activity of Na(+)-K(+)-ATPase [(3.78+/-1.14) U/L vs. (6.22+/-1.23) U/L, P<0.01]. The pathology of lung was milder in low temperature group compared with that of ambient temperature group.</AbstractText>Hypothermia therapy with infusion of 4 centigrade NS can reduce the release of pro-inflammatory mediators, inhibit the ATPase activity of alveolar membrane, and shows a protective effect on lung tissue against low perfusion.</AbstractText> |
5,846 | Influence of coffee and caffeine consumption on atrial fibrillation in hypertensive patients. | Coffee and caffeine are widely consumed in Western countries. Little information is available on the influence of coffee and caffeine consumption on atrial fibrillation (AF) in hypertensive patients. We sought to investigate the relationship between coffee consumption and atrial fibrillation with regard to spontaneous conversion of arrhythmia.</AbstractText>A group of 600 patients presenting with a first known episode of AF was investigated, and we identified 247 hypertensive patients. The prevalence of nutritional parameters was assessed with a food frequency questionnaire. Coffee and caffeine intake were specifically estimated. Left ventricular hypertrophy was evaluated by electrocardiogram (ECG) and echocardiogram. Coffee consumption was higher in normotensive patients. High coffee consumers were more frequent in normotensive patients compared with hypertensive patients. On the other hand, the intake of caffeine was similar in hypertensive and normotensive patients, owing to a higher intake in hypertensive patients from sources other than coffee. Within normotensive patients, we report that non-habitual and low coffee consumers showed the highest probability of spontaneous conversion (OR 1.93 95%CI 0.88-3.23; p=0.001), whereas, within hypertensive patients, moderate but not high coffee consumers had the lowest probability of spontaneous conversion (OR 1.13 95%CI 0.67-1.99; p=0.05).</AbstractText>Coffee and caffeine consumption influence spontaneous conversion of atrial fibrillation. Normotensive non-habitual coffee consumers are more likely to convert arrhythmia within 48h from the onset of symptoms. Hypertensive patients showed a U-shaped relationship between coffee consumption and spontaneous conversion of AF, moderate coffee consumers were less likely to show spontaneous conversion of arrhythmia. Patients with left ventricular hypertrophy showed a reduced rate of spontaneous conversion of arrhythmia.</AbstractText>Copyright © 2009 Elsevier B.V. All rights reserved.</CopyrightInformation> |
5,847 | On the reliability of frequency components in systolic arterial pressure in patients with atrial fibrillation. | Atrial fibrillation (AF) is characterized by desynchronization of atrial electrical activity causing a consequent irregular ventricular response. In AF, the beat-to-beat variation of blood pressure is increased because of variations in filling time and contractility. However, only a few studies have analyzed short-term blood pressure variations in AF, and we have recently observed a harmonic low-frequency (LF) component in systolic arterial pressure (SAP) during AF. Aim of the present study is to propose a method to verify the reliability of the spectral component found in SAP series, based on the position of the poles of the autoregressive spectral decomposition in the z-plane. In particular, 1,000 random permutations of the series allowed the definition of an area in the z-plane where poles from random process are likely to occur. Poles lying outside this area are considered as reliable oscillations. We tested the method on 53 recordings obtained at rest from patients with persistent AF. LF component was found in, respectively, 51 and 43 recordings in SAP and RR series. High-frequency (HF) component was found in all the recordings for both SAP and RR series. Using the proposed test, the percentage of reliable components in LF and HF bands was 80 and 38 in SAP series, and 20 and 18 in RR series. We concluded that, at variance with RR ones, SAP LF components are likely to represent true physiological oscillations. |
5,848 | Late sinus and atrial tachycardia after pediatric heart transplantation might predict poor outcome. | Our objective was to examine clinical/electrocardiogram (ECG) predictors and outcomes of arrhythmias beyond 1 year after pediatric heart transplantation (HTx). We performed a retrospective chart review of 94 1-year HTx survivors, 1988-2006. Clinical records identified patients with arrhythmias occurring >1 year after HTx requiring pharmacotherapy, excluding acute rejection. We reviewed preoperative diagnosis, gender, age at HTx, operative details, transplant coronary artery disease (TCAD), and mortality. We analyzed serial ECGs after HTx for HR, PR, QRS, QT, and QTc intervals. Our results found complete data in 58 patients, 14 (24%) with arrhythmia and 44 controls. Arrhythmias occurred 1.1-17.9 years after HTx (mean = 6.8): 11 focal atrial tachycardia, 1 atrial fibrillation/flutter, 1 atrioventricular node reentry tachycardia; only 1 patient had ventricular tachycardia (VT). Serial ECG intervals were similar between groups, as well as surgical technique, ischemic time, and rejection history. Seven patients (50%) with arrhythmias had death or graft death versus 11% of the controls (P = 0.006). Patients with arrhythmias were more likely to be diagnosed with TCAD (P = 0.007). The patient with VT had no TCAD. In conclusion, supraventricular arrhythmias were frequent (22%) in 1-year survivors of pediatric HTx. These patients were more likely to develop TCAD and/or graft loss/mortality. |
5,849 | Changes in interleukin-10 mRNA expression are predictive for 9-day survival of pigs in an emergency preservation and resuscitation model. | This study aimed at evaluating (I) the impact of different intra-arrest hypothermia levels on the expression of selected cytokines and (II) their prognostic value for 9-day survival.</AbstractText>Female Large White pigs (n=21, 31-38 kg) were subjected to 15 min of ventricular fibrillation, followed by intra-arrest cardiopulmonary bypass cooling for 1, 3, or 5 min achieving brain temperatures (Tbr) of 30.4+/-1.6, 24.2+/-4.6 and 18.8+/-4.0 degrees C. After 40 min of controlled rewarming, pigs were defibrillated and kept at Tbr of 34.5 degrees C for 20 h, survival was for 9 days. Plasma samples were analysed for interleukin (IL)-6, tumor necrosis factor-alpha (TNF-alpha), and IL-10 levels by ELISA. Total RNA out of peripheral blood mononuclear cells was analysed by real-time PCR for IL-1, IL-2, IL-4, IL-10, TNF-alpha, interferon-gamma, inducible NO synthase, and heme oxygenase-1 gene expressions.</AbstractText>Plasma IL-6 and TNF-alpha levels significantly (p=0.0001 and 0.0003) increased in all animals within 1h after resuscitation with no significant differences between groups. Pigs surviving exhibited a decrease in IL-10 expression between baseline and intra-arrest values as compared to non-surviving animals, which showed a slight increase (p=0.0078). ROC curve analysis revealed that changes in IL-10 expression had a good prognostic power for survival to day 9 (area under the curve=0.882).</AbstractText>The systemic inflammatory response syndrome after cardiac arrest was reflected by a remarkable increase of plasma IL-6 and TNF-alpha levels. Intra-arrest hypothermia levels did not influence the expression of selected cytokines. As prognostic marker for survival IL-10 was identified with decreasing mRNA levels during cardiac arrest in survivors.</AbstractText>Copyright 2010 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
5,850 | Fatty acid percentage in erythrocyte membranes of atrial flutter/fibrillation patients and controls. | Several epidemiological published data support the protective role of omega-3 consumption in coronary artery disease, sudden cardiac death and ventricular arrhythmias, but interestingly, this is not the case for atrial arrhythmias. The purpose of this study is to evaluate different fatty acid profile between AF/AFL subjects and healthy controls.</AbstractText>Gas chromatography was employed to determine fatty acid percentage of erythrocyte membranes from 40 idiopathic AFL/AF patients and 53 healthy control subjects.</AbstractText>AFL/AF erythrocyte membranes had significantly lower percentage of saturated fatty acid (43.1 +/- SD2.2 versus 47.8 +/- SD9.6, p < 0.001), monounsaturated fatty acid (18.2 +/- SD2.5 versus 22.6 +/- SD5.2, p < 0.001) and total trans fatty acid (0.2 +/- SD0.1 vs 1.3 +/- SD1.1, p < 0.001) than controls. Furthermore, fatty acid (FA) profiles of arrhythmic individuals showed an increased percent of total polyunsaturated fatty acid (PUFA) (36.7 +/- SD2.4 versus 26.4 +/- SD10.4, p < 0.001), PUFA n-3 (5.3 +/- SD1.1 versus 2.8 +/- SD1.8, p < 0.001) and n-6 (31.4 +/- SD2.2 versus 23.5 +/- SD9.9, p < 0.001).</AbstractText>This study shows that the erythrocyte membranes FA composition of AF/AFL subjects differs from that of healthy controls.</AbstractText> |
5,851 | Determinants of delayed preconditioning against myocardial stunning in chronically-instrumented pigs. | To test the hypothesis that a critical stenosis prevents delayed preconditioning against stunning, studies were conducted in pigs chronically-instrumented with occluders and segment-shortening crystals. In the setting of a critical stenosis, a preconditioning stimulus of repetitive brief occlusions resulted in infarction. Thereafter, a single 10-minute occlusion was used as the preconditioning stimulus. Delayed preconditioning against stunning was documented on subsequent days by the deficit-of-function following brief repetitive occlusions. In contrast to experiments in the naïve heart, the deficit-of-function improved on the day after a single 10-minute occlusion (from 60+/-14 to 24+/-6 arbitrary units, p=0.003), and similar improvement occurred when reperfusion was performed through a critical stenosis (32+/-6 units, p=0.02 vs. naïve and p=0.34 vs. no stenosis). Delayed preconditioning also reduced the frequency of ventricular fibrillation, and produced a 4-fold increase in both calcium-dependent and calcium-independent NOS activity. Thus, a critical stenosis did not prevent delayed preconditioning against stunning. |
5,852 | Outcomes from low versus high-flow cardiopulmonary resuscitation in a swine model of cardiac arrest. | Return of spontaneous circulation (ROSC) is improved by greater vital organ blood flow during cardiopulmonary resuscitation (CPR). We tested the hypothesis that myocardial flow above the threshold needed for ROSC may be associated with greater vital organ injury and worse outcome.</AbstractText>Aortic and right atrial pressures were measured with micromanometers in 27 swine. After 10 minutes of untreated ventricular fibrillation, chest compression was performed with an automatic, load-distributing band. Animals were randomly assigned to receive flows just sufficient for ROSC (low flow: target coronary perfusion pressure = 12 mm Hg) or well above the minimally effective level (high flow: coronary perfusion pressure = 30 mm Hg). Myocardial flow was measured with microspheres, defibrillation was performed after 3.5 minutes of CPR, and ejection fraction was measured with echocardiography.</AbstractText>Return of spontaneous circulation was achieved by 9 of 9 animals in the high-flow group and 15 of 18 in the low-flow group. All animals in the high-flow group defibrillated initially into a perfusing rhythm, whereas 12 of 15 animals achieving ROSC in the low-flow group defibrillated initially into pulseless electrical activity (P < .05, Fisher exact test). Compared with animals in the low-flow group, animals in the high-flow group had shorter resuscitation times, higher mean aortic pressures at ROSC, and higher ejection fractions at 2 hours post-ROSC (all P < .05).</AbstractText>High-flow CPR significantly improved arrest hemodynamics, rates of ROSC, and post-ROSC indicators of myocardial status, all indicating less injury with higher flows. No evidence of organ injury from vital organ blood flow substantially above the threshold for ROSC was found.</AbstractText>Copyright 2010 Elsevier Inc. All rights reserved.</CopyrightInformation> |
5,853 | Mild hypothermia alone or in combination with anesthetic post-conditioning reduces expression of inflammatory cytokines in the cerebral cortex of pigs after cardiopulmonary resuscitation. | Hypothermia improves survival and neurological recovery after cardiac arrest. Pro-inflammatory cytokines have been implicated in focal cerebral ischemia/reperfusion injury. It is unknown whether cardiac arrest also triggers the release of cerebral inflammatory molecules, and whether therapeutic hypothermia alters this inflammatory response. This study sought to examine whether hypothermia or the combination of hypothermia with anesthetic post-conditioning with sevoflurane affect cerebral inflammatory response after cardiopulmonary resuscitation.</AbstractText>Thirty pigs (28 to 34 kg) were subjected to cardiac arrest following temporary coronary artery occlusion. After seven minutes of ventricular fibrillation and two minutes of basic life support, advanced cardiac life support was started according to the current American Heart Association guidelines. Return of spontaneous circulation was achieved in 21 animals who were randomized to either normothermia at 38 degrees C, hypothermia at 33 degrees C or hypothermia at 33 degrees C combined with sevoflurane (each group: n = 7) for 24 hours. The effects of hypothermia and the combination of hypothermia with sevoflurane on cerebral inflammatory response after cardiopulmonary resuscitation were studied using tissue samples from the cerebral cortex of pigs euthanized after 24 hours and employing quantitative RT-PCR and ELISA techniques.</AbstractText>Global cerebral ischemia following resuscitation resulted in significant upregulation of cerebral tissue inflammatory cytokine mRNA expression (mean +/- SD; interleukin (IL)-1beta 8.7 +/- 4.0, IL-6 4.3 +/- 2.6, IL-10 2.5 +/- 1.6, tumor necrosis factor (TNF)alpha 2.8 +/- 1.8, intercellular adhesion molecule-1 (ICAM-1) 4.0 +/- 1.9-fold compared with sham control) and IL-1beta protein concentration (1.9 +/- 0.6-fold compared with sham control). Hypothermia was associated with a significant (P < 0.05 versus normothermia) reduction in cerebral inflammatory cytokine mRNA expression (IL-1beta 1.7 +/- 1.0, IL-6 2.2 +/- 1.1, IL-10 0.8 +/- 0.4, TNFalpha 1.1 +/- 0.6, ICAM-1 1.9 +/- 0.7-fold compared with sham control). These results were also confirmed for IL-1beta on protein level. Experimental settings employing hypothermia in combination with sevoflurane showed that the volatile anesthetic did not confer additional anti-inflammatory effects compared with hypothermia alone.</AbstractText>Mild therapeutic hypothermia resulted in decreased expression of typical cerebral inflammatory mediators after cardiopulmonary resuscitation. This may confer, at least in part, neuroprotection following global cerebral ischemia and resuscitation.</AbstractText> |
5,854 | Epilepsy or syncope? An analysis of 55 consecutive patients with loss of consciousness, convulsions, falls, and no EEG abnormalities. | Patients with loss of consciousness and convulsion often have the diagnosis of epilepsy despite normal electroencephalograms (EEGs).</AbstractText>To evaluate the proportion of patients referred to neurologists with presumed epilepsy and normal EEGs who have an alternative cause of syncope.</AbstractText>It was a cross-sectional study of 55 consecutive patients aged 6-85 (41 +/- 24) years presenting with faints, falls, convulsions, and normal EEGs, who were referred to neurologists before going to cardiologists. All patients underwent clinical examination, electrocardiogram, and echocardiogram. Head-up tilt table testing (HUT), 24-hour-Holter, and carotid sinus massage was offered as needed. Electrophysiological studies were undertaken in patients with structural heart disease or severe palpitations.</AbstractText>Anticonvulsant agents had been prescribed to 35 patients (64%) before entering the study. Vasovagal syncope was found in 22 (40%) patients, life-threatening arrhythmias in seven (13%), carotid sinus hypersensitivity in six (11%), orthostatic hypotension in three (5%), and aortic stenosis in one (2%). Etiology of syncope could not be found in 16 (29%) patients. Arrhythmias comprised two complete atrioventricular blocks, one sustained monomorphic ventricular tachycardia, one ventricular fibrillation, one atrial tachycardia, and two atrioventricular node reentrant tachycardias. Two patients developed a prolonged asystole during HUT. Presumptive diagnosis of syncope was found in 39 patients (71%). Patients on or off anticonvulsant drugs had 64% and 84% diagnosis of syncope, respectively (odds ratio = 0.33; 95% confidence interval 0.08-1.36; P = 0.13).</AbstractText>Life-threatening arrhythmias and syncope can be present in patients with presumed epilepsy and normal EEG. Prescription of anticonvulsant agents in these patients should wait for a cardiovascular assessment.</AbstractText> |
5,855 | Ablation of severe drug-resistant tachyarrhythmia during pregnancy. | The goal of this study was to describe mapping and ablation of severe arrhythmias during pregnancy, with minimum or no X-ray exposure. Treatment of tachyarrhythmia in pregnancy is a clinical problem. Pharmacotherapy entails a risk of adverse effects and is unsuccessful in some patients. Radiofrequency ablation has been performed rarely, because of fetal X-ray exposure and potential maternal and fetus complications. GROUP AND METHOD: Mapping and ablation was performed in 9 women (age 24-34 years) at 12-38th week of pregnancy. Three had permanent junctional reciprocating tachycardia, and 2 had incessant atrial tachycardia. Four of them had left ventricular ejection fraction < or =45%. One patient had atrioventricular nodal reciprocating tachycardia requiring cardioversion. Three patients had Wolff-Parkinson-White syndrome. Two of them had atrial fibrillation with ventricular rate 300 bpm and 1 had atrioventricular tachycardia 300 bpm. Fetal echocardiography was performed before and after the procedure.</AbstractText>Three women had an electroanatomic map and ablation done without X-ray exposure. The mean fluoroscopy time in the whole group was 42 +/- 37 seconds. The mean procedure time was 56 +/- 18 minutes. After the procedure, all women and fetuses were in good condition. After a mean period of 43 +/- 23 months follow up (FU), all patients were free of arrhythmia without complications related to ablation either in the mothers or children.</AbstractText>Ablation can be performed safely with no or minimal radiation exposure during pregnancy. In the setting of malignant, drug-resistant arrhythmia, ablation may be considered a therapeutic option in selected cases.</AbstractText> |
5,856 | Extracorporeal membrane oxygenation as a rescue of intractable ventricular fibrillation and bridge to heart transplantation. | Extracorporeal membrane oxygenation (ECMO) systems have undergone rapid technological improvements and are now feasible options for medium-term support of severe cardiac or pulmonary failure. Intractable ventricular arrhythmia is a rare but well-established indication for heart transplantation. We report a case of persistent ventricular fibrillation (VF) that was rescued by insertion of peripheral veno-arterial ECMO during cardiopulmonary resuscitation, which provided support for 30 h of continuous VF and subsequently permitted urgent heart transplantation. |
5,857 | Plasma levels of von Willebrand factor are increased in patients with hypertrophic cardiomyopathy. | Hypertrophic cardiomyopathy (HCM) is characterised by inappropriate hypertrophy, small-vessel coronary artery disease, myocyte disarray and increased interstitial fibrosis. Microvascular dysfunction is a common finding in HCM and its extent has been proposed as an important prognostic marker. Plasma von Willebrand factor (vWf) is an established marker of endothelial damage or dysfunction; however it has scarcely been studied in HCM. We hypothesised that vWf could be raised in patients with HCM and be related to different variables associated with severity of HCM.</AbstractText>We included 124 HCM patients, 93 males, aged 48+/-15 years, 59 healthy control subjects with similar age and sex and 20 patients with ischemic heart disease but clinical stability for the last 6 months. A complete history and clinical examination was performed, including 12-lead electrocardiogram, echocardiography, 24 hours ECG-Holter monitoring, and symptom limited treadmill exercise test. Risk factors for sudden death were evaluated. A blinded cardiac MRI was performed with late enhanced study with Gadolinium. Plasma vWf levels were assayed by commercial ELISA.</AbstractText>Patients showed higher levels of vWf (140.0+/-65.0 UI/ml vs 105.0+/-51.0 UI/ml, p<0.001) even after adjusting for ABO blood group. vWf levels were found raised in patients with severe functional class (168.4+/-65.9 UI/mL vs 132.4+/-60.7 UI/mL, p=0.020), atrial fibrillation (175.8+/-69.4 UI/mL vs 133.0+/-59.0 UI/mL, p=0.005), hypertension (161.4+/-60.8 vs 128.9+/-60.5, p=0.010) obstruction (153.9+/-67.9 vs 128.2+/-57.4 UI/mL, p=0.046) and non sustained ventricular tachycardia (159.3+/-59.1 vs 133.0+/-63.0, p=0.049). vWf correlated with age (r:0.26; p=0.006) and obstruction (r:0.22; p=0.021).</AbstractText>We show, for the first time, patients with HCM present significantly raised levels of vWf. These are associated with different conditions related to the severity of the disease.</AbstractText>Copyright (c) 2010 Elsevier Ltd. All rights reserved.</CopyrightInformation> |
5,858 | Ion channel trafficking: a new therapeutic horizon for atrial fibrillation. | Atrial fibrillation (AF) is a common cardiac arrhythmia with potentially life-threatening complications. Drug therapies for treatment of AF that seek long-term maintenance of normal sinus rhythm remain elusive due in large part to proarrhythmic ventricular actions. Kv1.5, which underlies the atrial specific I(Kur) current, is a major focus of research efforts seeking new therapeutic strategies and targets. Recent work has shown a novel effect of antiarrhythmic drugs where compounds that block Kv1.5 channel current also can alter ion channel trafficking. This work further suggests that the pleiotropic effects of antiarrhythmic drugs may be separable. Although this finding highlights the therapeutic potential for selective manipulation of ion channel surface density, it also reveals an uncertainty regarding the specificity of modulating trafficking pathways without risk of off-target effects. Future studies may show that specific alteration of Kv1.5 trafficking can overcome the proarrhythmic limitations of current pharmacotherapy and provide an effective method for long-term cardioversion in AF. |
5,859 | Atrioventricular nodal ablation predicts survival benefit in patients with atrial fibrillation receiving cardiac resynchronization therapy. | Cardiac resynchronization therapy (CRT) benefits patients with advanced heart failure. The role of atrioventricular nodal (AVN) ablation in improving CRT outcomes, including survival benefit in CRT recipients with atrial fibrillation, is uncertain.</AbstractText>The purpose of this study was to assess the impact of AVN ablation on clinical and survival outcomes in a large atrial fibrillation and heart failure population that met the current indication for CRT and to determine whether AVN ablation is an independent predictor of survival in CRT recipients.</AbstractText>Of 154 patients with atrial fibrillation who received CRT-D, 45 (29%) underwent AVN ablation (+AVN-ABL group), whereas 109 (71%) received drug therapy for rate control during CRT (-AVN-ABL group). New York Heart Association (NYHA) class, electrocardiogram, and echocardiogram were assessed before and after CRT. Survival data were obtained from the national death and location database (Accurint).</AbstractText>CRT comparably improved left ventricular ejection fraction (8.1% +/- 10.7% vs 6.8% +/- 9.6%, P = .49) and left ventricular end-diastolic diameter (-2.1 +/- 5.9 mm vs -2.1 +/- 6.7 mm, P = .74) in both +AVN-ABL and -AVN-ABL groups. Improvement in NYHA class was significantly greater in the +AVN-ABL group than in -AVN-ABL group (-0.7 +/- 0.8 vs -0.4 +/- 0.8, P = .04). Survival estimates at 2 years were 96.0% (95% confidence interval [CI] 88.6%-100%) for +AVN-ABL group and 76.5% (95% CI 68.1%-85.8%) for-AVN-ABL group (P = .008). AVN ablation was independently associated with survival benefit from death (hazard ratio [HR] 0.13, 95% CI 0.03-0.58, P = .007) and from combined death, heart transplant, and left ventricular assist device (HR 0.19, 95% CI 0.06-0.62, P = .006) after CRT.</AbstractText>Among patients with atrial fibrillation and heart failure receiving CRT, AVN ablation for definitive biventricular pacing provides greater improvement in NYHA class and survival benefit. Larger-scale randomized trials are needed to assess the clinical and survival outcomes of this therapy.</AbstractText>Copyright 2010 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
5,860 | Microvolt T-wave alternans and electrophysiologic testing predict distinct arrhythmia substrates: implications for identifying patients at risk for sudden cardiac death. | Better risk stratification of patients receiving an implantable cardioverter-defibrillator (ICD) for primary prevention of sudden cardiac death (SCD) is needed. Although microvolt T-wave alternans (MTWA) and electrophysiologic study (EPS) are independent markers for SCD, the Alternans Before Cardioverter Defibrillator (ABCD) trial found the combination to be more predictive than either test alone.</AbstractText>The purpose of this study was to test the hypothesis that EPS and MTWA measure different elements of the arrhythmogenic substrate and, therefore, predict distinct arrhythmia outcomes.</AbstractText>The ABCD trial enrolled 566 patients with ischemic cardiomyopathy, left ventricular ejection fraction (LVEF) <or=0.40, and nonsustained ventricular tachycardia. All patients underwent both MTWA test and EPS. The performance of MTWA and EPS in predicting stable ventricular tachyarrhythmic events (S-VTEs) versus unstable ventricular tachyarrhythmic events (U-VTEs), defined as either polymorphic ventricular tachycardia or ventricular fibrillation, was analyzed using Kaplan-Meier event rates and the log rank test.</AbstractText>MTWA and EPS were abnormal in 71% and 39% of patients, respectively. There were 28 S-VTEs and 10 U-VTEs. MTWA was predictive of U-VTEs (event rate 2.7% in abnormals vs 0% in normals, P = .04), whereas EPS was not (1.5% vs 3.2%, P = .55). In contrast, EPS predicted S-VTEs (9.7% vs 2.2%, P <.01), but MTWA did not (5.5% vs 4.4%, P = .57). Whereas the extent of left ventricular contractile dysfunction alone (LVEF <or=0.30 vs LVEF 0.31-0.40) did not predict events, MTWA predicted events better than did EPS in subjects with LVEF <or=0.30. In contrast, EPS predicted events better than did MTWA test in subjects with LVEF >0.30.</AbstractText>The study data suggest that EPS and MTWA identify distinct arrhythmogenic substrates and, when used in combination, may better predict the complex electroanatomic substrates that underlie the risk for SCD.</AbstractText>Copyright (c) 2010. Published by Elsevier Inc.</CopyrightInformation> |
5,861 | Assessment of ECG interval and restitution parameters in the canine model of short QT syndrome. | The short QT syndrome (SQTS) is characterized by a short QT interval resulting from accelerated ventricular repolarization, and may be associated with ventricular fibrillation but not torsades de pointes. There are abundant data on the adverse effects of long QT, but knowledge of SQTS is sparse. The aim of this study was to examine whether analyses of several ECG biomarkers (QT, QTcB, QTcF, QTcV, QT(btb), and QT(RR1000)) and dynamic restitution of the beat-to-beat QT-TQ relationship (TQ(min), %QT/TQ ratio>1, QT/TQ ratio(max)) can be used to assess ECG changes in conscious dogs.</AbstractText>Sling-trained dogs were infused with escalating concentration of levcromakalim (0, 1.0, 3.3, and 10.0 microg/kg/min), pinacidil (0, 3.3, 10.0, and 33.3 microg/kg/min), and nicorandil (0, 0.03, 0.1, and 0.3 mg/kg/min), drugs known to shorten QT. The RR, QT, QTcB, QTcF, QTcV, QT(RR1000), and TQ were measured before and after each concentration of the QT shortening test compounds.</AbstractText>Levcromakalim, pinacidil, and nicorandil but not vehicle significantly shortened RR, QT, QT(btb), QT(RR1000), and TQ but not QTc(B,F,V). The QT-RR cloud also shifted to the lower bounds of the normal QT-RR boundary by the test compounds. The percentage of beats with a QT/TQ ratio>1 was significantly increased in a dose response manner with levcromakalim and pinacidil and the lower TQ interval boundary (5th percentile) was decreased when compared to baseline or vehicle.</AbstractText>QT(btb), QT(RR1000), and dynamic beat-to-beat measurements of restitution constitute clinically applicable ECG biomarkers for assessment of changes associated with arrhythmogenic risk of ventricular fibrillation due to QT abbreviation.</AbstractText>2010. Published by Elsevier Inc.</CopyrightInformation> |
5,862 | Infliximab attenuates early myocardial dysfunction after resuscitation in a swine cardiac arrest model. | Left ventricular dysfunction after successful cardiopulmonary resuscitation contributes to early death after resuscitation. Proinflammatory cytokines are known to decrease myocardial function, and tumor necrosis factor-alpha has been shown to increase after successful resuscitation. We hypothesized that blocking the effects of tumor necrosis factor-alpha with infliximab would prevent or minimize postresuscitation cardiac dysfunction.</AbstractText>Randomized, placebo-controlled comparative study.</AbstractText>Large animal research laboratory.</AbstractText>Twenty-eight anesthetized and instrumented domestic male swine (Yorkshire and Yorkshire/Hampshire mix; weight, 35-45 kg).</AbstractText>Infusion of infliximab (5 mg/kg) or normal saline after resuscitation from ventricular fibrillation cardiac arrest.</AbstractText>Hemodynamic variables, indices of left ventricular function, and tumor necrosis factor-alpha were measured before and after 8 mins of cardiac arrest during the early postresuscitation period (3 hrs). Within 5 mins of restoration of spontaneous circulation, 14 animals received infliximab, 5 mg/kg, infused over 30 mins. Fourteen animals received an infusion of normal saline. Inotropes and vasopressors were not administered to either group after resuscitation. Tumor necrosis factor-alpha increased after restoration of circulation and remained elevated throughout the observation period. Differences between groups were not significant. Interleukin-1beta concentration did not change significantly during the observation period in either study group. Mean arterial pressure and stroke work were significantly greater in the infliximab group within 30 mins of resuscitation, and these differences were sustained throughout the 3-hr postresuscitation period. The effect of tumor necrosis factor-alpha blockade was evident only in animals with a significant increase (doubling) in plasma tumor necrosis factor-alpha at 30 mins after arrest.</AbstractText>Tumor necrosis factor-alpha plays a role in cardiac dysfunction after arrest and infliximab may attenuate or prevent postresuscitation myocardial dysfunction when administered immediately after resuscitation.</AbstractText> |
5,863 | Obstructive sleep apnea is common and independently associated with atrial fibrillation in patients with hypertrophic cardiomyopathy. | Hypertrophic cardiomyopathy (HCM) is associated with arrhythmias and cardiovascular death. Left atrial enlargement and atrial fibrillation (AF) are considered markers for death due to heart failure in patients with HCM. Obstructive sleep apnea (OSA) is independently associated with heart remodeling and arrhythmias in other populations. We hypothesized that OSA is common and is associated with heart remodeling and AF in patients with HCM.</AbstractText>We evaluated 80 consecutive stable patients with a confirmed diagnosis of HCM by sleep questionnaire, blood tests, echocardiography, and sleep study (overnight respiratory monitoring).</AbstractText>OSA (apnea-hypopnea index [AHI] > 15 events/h) was present in 32 patients (40%). Patients with OSA were significantly older (56 [41-64] vs 38.5 [30-53] years, P < .001) and presented higher BMI (28.2 +/- 3.5 vs 25.2 +/- 5.2 kg/m(2), P < .01) and increased left atrial diameter (45 [42-52.8] vs 41 [39-47] mm, P = .01) and aorta diameter (34 [30-37] vs 29 [28-32] mm, P < .001), compared with patients without OSA. Stepwise multiple linear regression showed that the AHI (P = .05) and BMI (P = .06) were associated with left atrial diameter. The AHI was the only variable associated with aorta diameter (P = .01). AF was present in 31% vs 6% of patients with and without OSA, respectively (P < .01). OSA (P = .03) and left atrial diameter (P = .03) were the only factors independently associated with AF.</AbstractText>OSA is highly prevalent in patients with HCM and it is associated with left atrial and aortic enlargement. OSA is independently associated with AF, a risk factor for cardiovascular death in this population.</AbstractText> |
5,864 | [Prognostic factors of mortality in a cohort of patients with in-hospital cardiorespiratory arrest]. | To define the prognostic factors related with mortality of patients who suffer cardiorespiratory arrest (CRA) in the hospital, according to Utstein style guidelines.</AbstractText>A descriptive and prospective study covering a 30-month consecutive period of all the patients who suffered at least one episode of in-hospital CRA. A Cox regression multivariate analysis was made to identify the independent factors associated with mortality.</AbstractText>A medical-surgical center in Hospital "Virgen de las Nieves" (HUVN), Granada (Spain).</AbstractText>All the patients attended due to CRA in the hospital, except for those occurring in the operating and recovery room areas. They were followed-up to hospital discharge.</AbstractText>Mortality on hospital discharge.</AbstractText>203 patients who suffered at least one cardiorespiratory arrest in the hospital, with a median age of 67 years and preponderance of male (60.6%). The most common location was in intensive care medicine unit (48%) and cardiac etiology (62%). Hospital survival rate was 23.15%. In multivariate analysis, strong predictors of mortality were administration of any dose of epinephrine during resuscitation maneuvers (OR 3.4; CI 95%. 1.6-7), total duration of resuscitation (HR 1.018; CI 95%, 1.012-1.024) and as protective factors the first ventricular fibrillation/ventricular tachycardia rhythm with no pulse (HR 0.6; CI 95%, 0.4-0.9) and witnessed by a doctor (HR 0.6; CI 95%, 0.5-0.9).</AbstractText>The type of witness was identified among the predictors of mortality on hospital discharge after an episode of cardiac arrest. This becomes important because the qualification of healthcare personnel can be improved through adequate training.</AbstractText>Copyright 2008 Elsevier España, S.L. y SEMICYUC. All rights reserved.</CopyrightInformation> |
5,865 | J wave syndromes. | The J wave, also referred to as an Osborn wave, is a deflection immediately following the QRS complex of the surface ECG. When partially buried in the R wave, the J wave appears as J-point elevation or ST-segment elevation. Several lines of evidence have suggested that arrhythmias associated with an early repolarization pattern in the inferior or mid to lateral precordial leads, Brugada syndrome, or arrhythmias associated with hypothermia and the acute phase of ST-segment elevation myocardial infarction are mechanistically linked to abnormalities in the manifestation of the transient outward current (I(to))-mediated J wave. Although Brugada syndrome and early repolarization syndrome differ with respect to the magnitude and lead location of abnormal J-wave manifestation, they can be considered to represent a continuous spectrum of phenotypic expression that we propose be termed J-wave syndromes. This review summarizes our current state of knowledge concerning J-wave syndromes, bridging basic and clinical aspects. We propose to divide early repolarization syndrome into three subtypes: type 1, which displays an early repolarization pattern predominantly in the lateral precordial leads, is prevalent among healthy male athletes and is rarely seen in ventricular fibrillation survivors; type 2, which displays an early repolarization pattern predominantly in the inferior or inferolateral leads, is associated with a higher level of risk; and type 3, which displays an early repolarization pattern globally in the inferior, lateral, and right precordial leads, is associated with the highest level of risk for development of malignant arrhythmias and is often associated with ventricular fibrillation storms. |
5,866 | Biventricular pacing improves cardiac function and prevents further left atrial remodeling in patients with symptomatic atrial fibrillation after atrioventricular node ablation. | Randomized trials have demonstrated benefits of biventricular (BiV) pacing in patients with advanced heart failure, intraventricular conduction delay, and atrial fibrillation (AF) post-atrioventricular (AV) node ablation. The AV Node Ablation with CLS and CRT Pacing Therapies for Treatment of AF trial (AVAIL CLS/CRT) was designed to demonstrate superiority of BiV pacing in patients with AF after AV node ablation, to evaluate its effects on cardiac structure and function, and to investigate additional benefits of Closed Loop Stimulation (CLS) (BIOTRONIK, Berlin, Germany).</AbstractText>Patients with refractory AF underwent AV node ablation and were randomized (2:2:1) to BiV pacing with CLS, BiV pacing with accelerometer, or right ventricular (RV) pacing. Echocardiography was performed at baseline and 6 months, with paired data available for 108 patients.</AbstractText>The RV pacing contributed to significant increase in left atrial volume, left ventricular (LV) end-systolic volume, and LV mass compared to BiV pacing. Ejection fraction decreased insignificantly with RV pacing compared to significant increase with BiV pacing. Interventricular dyssynchrony significantly decreased with BiV compared with RV pacing. Closed Loop Stimulation did not result in additional echocardiographic changes; heart rate distribution was significantly wider with CLS. All groups showed significant improvement in 6-minute walk distance, quality-of-life score, and New York Heart Association class.</AbstractText>In conclusion, RV pacing results in significant increase in left atrial volume, LV mass, and worsening of LV contractility compared to patients receiving BiV pacing post-AV node ablation for refractory AF. Closed Loop Stimulation was not associated with additional structural changes but resulted in significantly wider heart rate distribution.</AbstractText>Copyright (c) 2010 Mosby, Inc. All rights reserved.</CopyrightInformation> |
5,867 | Influence of dedicated heart failure clinics on delivery of recommended therapies in outpatient cardiology practices: findings from the Registry to Improve the Use of Evidence-Based Heart Failure Therapies in the Outpatient Setting (IMPROVE HF). | National guidelines recommend heart failure (HF) disease management programs to facilitate adherence to evidence-based practices. This study examined the influence of dedicated HF clinics on delivery of guideline-recommended therapies for cardiology practice outpatients with HF and reduced left ventricular ejection fraction.</AbstractText>IMPROVE HF, a prospective cohort study, enrolled 167 cardiology practices to characterize outpatient management of 15,381 patients with chronic systolic HF. Adherence to guideline-recommended HF therapies was recorded, and the presence of a dedicated HF clinic was assessed by survey. Multivariate models identified contributions to delivery of guideline-recommended HF therapies.</AbstractText>Of practices, 41.3% had a dedicated HF clinic. Practices with a dedicated HF clinic had greater adherence to 3 of 7 guideline-recommended HF therapy measures: angiotensin-converting enzyme inhibitor/angiotensin receptor blocker (P = .02), beta-blocker (P = .025), and HF education (P = .009). After adjustment, use of a dedicated HF clinic was associated with greater conformity in 2 of 7 measures: cardiac resynchronization therapy (P = .036) and HF education (P = .005) but not angiotensin-converting enzyme inhibitor/angiotensin receptor blocker, beta-blocker, aldosterone antagonist, implantable cardioverter-defibrillator therapy, and anticoagulation for atrial fibrillation.</AbstractText>Use of dedicated HF clinics varied in cardiology outpatient practices and was associated with greater use of cardiac resynchronization therapy and HF education but not other guideline-recommended therapies.</AbstractText>Copyright (c) 2010 Mosby, Inc. All rights reserved.</CopyrightInformation> |
5,868 | Extracorporeal membrane oxygenation as a resuscitation measure in the emergency department. | A 53-year-old man presented to the ED with refractory ventricular fibrillation secondary to an occluded proximal left anterior descending coronary artery. We report the first case of extracorporeal membrane oxygenation instituted in our ED. It is one of the few reports in the literature of extracorporeal membrane oxygenation being utilized in the ED as a resuscitation measure. |
5,869 | Benefits of thyrotropin suppression versus the risks of adverse effects in differentiated thyroid cancer. | Despite clinical practice guidelines for the management of differentiated thyroid cancer (DTC), there are no recommendations on the optimal serum thyrotropin (TSH) concentration to reduce tumor recurrences and improve survival, while ensuring an optimal quality of life with minimal adverse effects. The aim of this review was to provide a risk-adapted management scheme for levothyroxine (L-T4) therapy in patients with DTC. The objective was to establish which patients require complete suppression of serum TSH levels, given their risk of recurrent or metastatic DTC, and how potential adverse effects on the heart and skeleton, induced by subclinical hyperthyroidism, in concert with advanced age and comorbidities, may influence the degree of TSH suppression.</AbstractText>A risk-stratified approach to predict the rate of recurrence and death from thyroid cancer was based on the recently revised American Thyroid Association guidelines. A stratified approach to predict the risk from the adverse effects of L-T4 was devised, taking into account the age of the patient, as well as the presence of preexisting cardiovascular and skeletal risk factors that might predispose to the development of long-term adverse cardiovascular or skeletal outcomes, particularly increased heart rate and left ventricular mass, atrial fibrillation, and osteoporosis. Nine potential patient categories can be defined, with differing TSH targets for both initial and long-term L-T4 therapy.</AbstractText>Before deciding on the degree of TSH suppression during initial and long-term L-T4 treatment in patients with DTC, it is necessary to consider the aggressiveness of DTC, as well as the potential for adverse effects induced by iatrogenic subclinical hyperthyroidism. More aggressive TSH suppression is indicated in patients with high-risk disease or recurrent tumor, whereas less aggressive TSH suppression is reasonable in low-risk patients. In patients with high-risk DTC and an equally high risk of adverse effects, long-term treatment with L-T4 therapy should be individualized and balanced against the potential for adverse effects. In patients with an intermediate risk for thyroid cancer recurrence and a high risk of adverse effects of therapy, the degree of TSH suppression should be reevaluated during the follow-up period. Normalization of serum TSH is advisable for long-term treatment of disease-free elderly patients with DTC and significant comorbidities.</AbstractText> |
5,870 | Transcatheter implantation of an aortic valve: anesthesiological management. | Transcatheter aortic valve implantation (TAVI) is an emergent alternative technique to surgery in high-risk patients with aortic stenosis. Here, we describe the anesthesiological management of patients undergoing TAVI at our institution over an 18-month period.</AbstractText>After a proper assessment of surgical risk and comorbidities, 69 patients underwent TAVI with the transfemoral/subclavian approach. Both Edwards-Sapien and Corevalve prostheses were implanted. The anesthetic regimen consisted of general anesthesia or local anesthesia plus sedation.</AbstractText>Twenty-seven patients received general anesthesia, and 42 received local anesthesia plus sedation. Procedural complications included prosthesis embolization (2), ascending aorta dissection (1), ventricular fibrillation following rapid ventricular pacing (8), vascular access site complications (17), and the valve-in-valve procedure (1). Three patients had to be converted from local anesthesia to general anesthesia (one patient had refractory ventricular fibrillation, and two patients were restless). All patients were alive at the 30-day follow-up. Mechanical ventilation time was 8.5+/-0.03 h. Mean ICU stay was 20.1+/-2.89 h. Postoperative complications included acute renal dysfunction (11), advanced atrioventricular block (9), and stroke (1). Thirty-six out of 42 (86%) patients were alive at the 6-month follow-up.</AbstractText>TAVI is feasible in high-risk patients who would not be able to undergo surgical valve replacement. Hemodynamic management is the main concern of intraoperative anesthesiological management. General or local anesthesia plus sedation are both valid alternative techniques that can be titrated according to patient characteristics. Close postoperative monitoring in the ICU is required.</AbstractText> |
5,871 | Case report: nonarrhythmogenic right ventricular dysplasia presenting with severe right ventricular failure in an adolescent. | Right ventricular dysplasia is usually discovered by the presence of ventricular arrhythmia. As arrhythmia is an epiphenomenon, the first presentation of some cases can be primarily heart failure. We describe an adolescent girl who presented with progressive right heart failure and whose hallmark was fibrofatty replacement of ventricular muscle, especially of the right side, without ventricular arrhythmia. The patient was successfully treated by orthotopic heart transplantation. |
5,872 | Management and comorbidities of atrial fibrillation in patients admitted in cardiology service in Kosovo-a single-center study. | Atrial fibrillation (AF) is the most important risk factor for ischemic stroke. Anticoagulation therapy can substantially decrease the risk of stroke in patients with AF. The aim of our study was to investigate the patient's comorbidities and management of patients with AF on the discharge.</AbstractText>From 5382 consecutive patients admitted in our institution between January 2005 and March 2008, 525 (mean age 66.4+/- 11.4 years, 53.3% male) had AF upon discharge, who were included in this retrospective study. Patients were divided in two groups according to prescription of anticoagulation therapy at discharge. Continuous data were compared between groups using a two-tailed unpaired Student t test. Discrete variables were compared using Chi-square test or Fisher's exact probability test as appropriate. Logistic regression analysis was used to identify the independent clinical and echocardiographic predictors of prescribing oral anticoagulation therapy.</AbstractText>Associated comorbidities of AF in our patients were: ischemic heart disease (21.4%), hypertensive heart disease (27.44%), valvular heart disease (17.4%), congestive heart failure (47%), chronic obstructive pulmonary disease (6.7%), and diabetes 14.3%). Of 525 patients 76% were discharged on beta-blockers, 67% on angiotensin converting enzyme inhibitors, 23% on digoxin, 16% on calcium antagonists, 67% on diuretics, 72% on aspirin, and 27% on oral anticoagulant (OAC) therapy, 11% were with both antithrombotics. Multivariate analysis showed that the under-prescription of OAC therapy in patients with AF was independently associated with elder age (OR=0.916, 95%CI 0.891-0.942, p<0.001), non-enlarged left atrium (OR=1.148, 95%CI 1.100-1.198, p<0.001) and good left ventricular ejection fraction (OR=0.970, 95%CI 0.948-0.993, p=0.011).</AbstractText>Patients with atrial fibrillation were mainly with ischemic, hypertensive heart disease and congestive heart failure. Our study, suggests underuse of anticoagulation therapy. The independent predictors of under prescription of anticoagulants in patients with atrial fibrillation were elder age, non-enlarged left atrium, and good left ventricular ejection fraction. Medical treatment with other groups of drugs for atrial fibrillation and comorbidities seems to be according to current guidelines.</AbstractText> |
5,873 | Comparative study of nifekalant versus amiodarone for shock-resistant ventricular fibrillation in out-of-hospital cardiopulmonary arrest patients. | In Japan, intravenous nifekalant (NIF) was often used for direct current cardioversion-resistant ventricular fibrillation (VF), until the use of intravenous amiodarone (AMD) was approved in 2007. The defibrillatory efficacy of NIF and AMD has thus far not been compared for resuscitation.</AbstractText>Between August 2007 and April 2009, 403 consecutive out-of-hospital patients with cardiopulmonary arrest were transferred to the Emergency Medical Service of Tokai University. Of these, 30 patients with first defibrillation failure or VF recurrence were enrolled for this NIF/AMD study. The final defibrillation success (and hospital survival rate) was 67% (10/15) in the AMD and 47% (7/15) in the NIF group. The discharge survival rate was 53% (8/15) in the AMD and 21% (4/15) in the NIF group (P = 0.06). Notably, all 4 survivors in the NIF group could take up normal daily life again, whereas this was restricted to only 2 patients from the 11 survivors in the AMD group. The difference is probably partly attributable to longer time from AMD administration to defibrillation success compared with NIF. In the cases of defibrillation failure, VF continued in 4/8 by NIF, however, asystole or pulseless electrical activity occurred in 4/5 patients by AMD.</AbstractText>AMD may be borderline superior over NIF to facilitate defibrillation in out-of-hospital patients with cardiopulmonary arrest. However, from the view point of preservation of brain function, NIF is not inferior to AMD for CPR.</AbstractText> |
5,874 | Clinical applications and acute hepatotoxicity of intravenous amiodarone. | This cross-sectional, retrospective study was designed to evaluate the current clinical applications and acute hepatotoxicity of intravenous amiodarone administration at a hospital in China. Clinical data were collected from 1214 patients receiving intravenous amiodarone treatment between October 2003 and September 2005. Baseline patient characteristics, drug indications, administration records and acute hepatotoxicity associated with the drug were examined. Amiodarone was used primarily in arrhythmic patients with obvious cardiac dysfunction. Atrial fibrillation and ventricular arrhythmia were the two most commonly treated dysfunctions. Incorrect indications and administration methods were also noted. Hepatotoxicity occurred in 12.6% of the patients, but was mild in most cases. Males showed a higher incidence of hepatotoxicity than females. The use of amiodarone was considered to be reasonable and standardized, but there was still considerable room for improvement, particularly in the standardization of administration guidelines. Intravenous amiodarone can cause hepatotoxicity and hepatic function tests should be performed soon after giving amiodarone intravenously. |
5,875 | Optimization of repolarization during biventricular pacing: a new target in patients with biventricular devices? | Evaluation of repolarization during sequentional biventricular pacing.</AbstractText>Patients with biventricular devices, and left ventricular leads placed to the basal part of lateral left ventricular wall were enrolled. QRS, QTc, JTc, and corrected Tpeak-Tend intervals were compared during sequentional biventricular, left ventricular, and right ventricular pacing.</AbstractText>Five patients with nonischemic and five with ischemic cardiomyopathy due to anterior myocardial infarction were enrolled. No correlation was observed between values of repolarization among patients. The optimal values of repolarization were significantly different from values of echocardiographically guided hemodynamic optimization. Two patients with biventricular pacing-induced ventricular fibrillation were successfully treated by reprogramming of V-V delay according to interventricular delay resulting in shorter Tpeak-Tend interval, although delayed effect of amiodarone in one of these patients cannot be ruled out.</AbstractText>Patients with biventricular devices may be prone to development of ventricular arrhythmias depending on programmed V-V interval. We suggest that optimization of repolarization may be performed in patients with biventricular pacemakers in the absence of backup ICD and those with frequent episodes of ventricular tachyarrhythmias, although this finding deserves further study.</AbstractText> |
5,876 | Right ventricular histological substrate and conduction delay in patients with Brugada syndrome. | The reported pathogenesis of Brugada syndrome is phase 2 reentry resulting from shortening of the epicardial action potential duration at the right ventricular outflow tract (RVOT). However, several studies have revealed a high incidence of ventricular late potentials and high rate of ventricular fibrillation (VF) induced by programmed ventricular stimulation (PVS). The aim of the present study was to evaluate the role of slow conduction at the RVOT for the initiation of VF by PVS and any underlying pathological conditions in Brugada syndrome. Endocardial mapping of the RVOT and endomyocardial biopsy of the right ventricle were performed in 25 patients with Brugada syndrome with inducible VF. Late potentials were positive in 11 of the 25 (44%) patients. Low-amplitude fragmented and delayed electrograms were recorded at the RVOT in 13 of 18 (72.2%) patients. Histologic examination of the biopsy samples revealed fatty tissue infiltration, interstitial fibrosis, lymphocyte infiltration, and/or myocyte disorganization in 13 patients. Slow conduction at the RVOT may contribute to the induction of VF by PVS in Brugada syndrome. Various pathomorphologic changes may contribute to slow conduction at the RVOT. |
5,877 | [Morphology of acute myocardial infarction at prenecrotic stage]. | We studied morphological changes of myocardium and content of glucose, potassium, calcium, sodium in pericardial fluid in persons who died suddenly of myocardial infarction at its prenecrotic stage at prehospital phase. It was established that acute myocardial infarction at prenecrotic stage can run in 2 morphological forms - either with transmural or with subendo- or epicardial localization of ischemic process in left ventricular wall. Transmural injury is characterized by large volume of ischemic damage of the left ventricle, generalized spasm of arterial system of the heart, changes of cardiomyocytes with derangement of their energy metabolism and contractile capacity. In subendo- or epicardial localization foci of ischemic injury alternated with areas of normal blood supply. Similar character of disturbances of rheological properties of blood with thrombosis of microcirculatory bed and of number of markers of ventricular fibrillation between these two forms create preconditions for increase of the zone of necrosis in myocardium and cause high risk of development of rhythm disorders. |
5,878 | Patient expectations from implantable defibrillators to prevent death in heart failure. | Indications for implantable cardioverter-defibrillators (ICDs) in heart failure (HF) are expanding and may include more than 1 million patients. This study examined patient expectations from ICDs for primary prevention of sudden death in HF.</AbstractText>Study participants (n = 105) had an EF <35% and symptomatic HF, without history of ventricular tachycardia/fibrillation or syncope. Subjects completed a written survey about perceived ICD benefits, survival expectations, and circumstances under which they might deactivate defibrillation. Mean age was 58, LVEF 21%, 40% were New York Heart Association Class III-IV, and 65% already had a primary prevention ICD. Most patients anticipated more than10 years survival despite symptomatic HF. Nearly 54% expected an ICD to save >or=50 lives per 100 during 5 years. ICD recipients expressed more confidence that the device would save their own lives compared with those without an ICD (P < .001). Despite understanding the ease of deactivation, 70% of ICD recipients indicated they would keep the ICD on even if dying of cancer, 55% even if having daily shocks, and none would inactivate defibrillation even if suffering constant dyspnea at rest.</AbstractText>HF patients anticipate long survival, overestimate survival benefits conferred by ICDs, and express reluctance to deactivate their devices even for end-stage disease.</AbstractText>Copyright 2010 Elsevier Inc. All rights reserved.</CopyrightInformation> |
5,879 | Reducing QT liability and proarrhythmic risk in drug discovery and development. | Drug-induced torsades de pointes (TdP), a rare, life-threatening, polymorphic, ventricular tachycardia associated with prolongation of the QT interval, has been the main safety reason for the withdrawal of medicines from clinical use over the last decade. Most often, drugs that prolong the action potential and delay ventricular repolarization do so through blockade of outward (repolarizing) currents, predominantly the rapid delayed rectifying potassium current, I(Kr). While QT interval prolongation is not a safety concern per se, in a small percentage of people, it has been associated with TdP, which either spontaneously terminates or degenerates into ventricular fibrillation. Furthermore, recent data suggest that shortening of the QT interval may also be a new safety issue waiting to surface. This review article summarizes the presentations given at a symposium entitled 'Reducing QT liability and proarrhythmic risk in drug discovery and development', which was part of the Federation of the European Pharmacological Societies congress, Manchester, UK, 13-17 July 2008. The objective of this symposium was to assess the effects of implementing the latest regulatory guidance documents (International Conference on Harmonization S7A/B and E14), as well as new scientific and technical trends on the ability of the pharmaceutical industry to reduce and manage the QT liability and associated potential proarrhythmic risk, and contribute to the discovery and development of safer medicines. This review outlines the key messages from communications presented at this symposium and attempts to highlight some of the key challenges that remain to be addressed. |
5,880 | [Severe coronary artery spasm immediately after aortic valve replacement]. | We report a case of 72-year-old man with severe manifestations of coronary artery spasm immediately after aortic valve replacement (AVR), which was associated with hemodynamic and arrhythmic instability. The AVR was performed under mild hypothermic cardiopulmonary bypass (34 degrees C), and retrograde blood cardioplegia was intermittently delivered at the same temperature. Immediately after the operation, the patient suddenly developed severe bradycardia and hypotension, and repeated ventricular fibrillation. Percutaneous cardiopulmonary support system (PCPS) and intra-aortic balloon pumping (IABP) were required for this circulatory collapse. Echocardiography revealed left ventricular segmental dysfunction, and coronary artery bypass grafting (CABG) to the right coronary artery and the left ascending artery was performed [during CABG, coronary spasm was strongly suspected by repetitive ST elevation and depression on electrocardiogram (ECG) monitor]. Eventually, the spasm subsided with the intravenous infusion of nitrates, nicorandil, and diltiazem. The remaining postoperative course was uneventful and the patient was discharged on the 24th postoperative day in good clinical condition. |
5,881 | MMP-2 and TIMP-2 gene polymorphisms and susceptibility to atrial fibrillation in Chinese Han patients with hypertensive heart disease. | MMP-2 and TIMP-2 play important roles in the pathogenesis of arrhythmogenic atrial remodeling, and may contribute to the development and persistence of atrial fibrillation (AF). Functional polymorphisms in the promoter of MMP-2 and TIMP-2 gene may modulate an individual's susceptibility to AF.</AbstractText>A total of 881 hypertensive heart disease patients from Chinese Han population (128 with and 753 without AF) were recruited in this study. The genotypes of the MMP2-1306C>T and -735C>T polymorphisms and TIMP-2 -418G>C polymorphisms were determined using PCR based method. The plasma concentration of TIMP-2 was measured by enzyme-linked immunosorbent assay in a subgroup with 81 patients.</AbstractText>Both genotype distribution and allele frequency of the TIMP-2 -418G>C polymorphism were significantly different between the AF and control group (P=0.005 and P=0.001, respectively). The C allele carriers (GC+CC) had a significantly increased risk of AF compared with the GG homozygotes (odds ratio,1.77, 95% CI 1.21-2.92, P=0.009) in a logistic regression model after adjustment for age, left atrial dimension, left ventricular mass index, and antihypertensive drugs. The C allele carriers also had reduced levels of plasma TIMP-2 levels compared with GG homozygotes in both AF patients and control subjects. No relationship was found in this cohort between the presence of the MMP-2 -1306C>T and -735C>T polymorphism and AF.</AbstractText>The TIMP-2 -418G>C polymorphism is significantly associated with an increased susceptibility to AF in Chinese Han patients with hypertensive heart disease. The -418C allele, which is associated with a decreased expression of TIMP-2, might be a genetic risk for the development of AF in this cohort.</AbstractText>Copyright 2010 Elsevier B.V. All rights reserved.</CopyrightInformation> |
5,882 | Left atrial electromechanical conduction time can predict six-month maintenance of sinus rhythm after electrical cardioversion in persistent atrial fibrillation by Doppler tissue echocardiography. | The purpose of this study was to determine whether atrial electromechanical conduction time (EMT) measured by echocardiography can predict 6-month maintenance of sinus rhythm (SR) after electrical cardioversion in patients with atrial fibrillation (AF).</AbstractText>Fifty-three patients with persistent AF (>1 month) who had successful cardioversion and 30 controls with SR were prospectively enrolled. SR maintenance was assessed during 6-month follow-up. EMT was measured as the time interval from the onset of the P wave on electrocardiography to the peak of the late diastolic wave from the septal and lateral mitral annulus (EMT-S and EMT-L, respectively) and the lateral tricuspid annulus (EMT-T) on tissue Doppler echocardiography.</AbstractText>Compared with controls, left atrial (LA) volume index, P-wave duration, and EMT were significantly larger in patients with AF (all P values<.001). In patients with AF, the duration of AF (P=.71) and P-wave duration (P=.24) were not different between the SR maintenance group (n=23) and the AF recurrence group (n=30), and there was a trend toward increased LA volume index in the AF recurrence group (47.0+/-12.4 vs 45.3+/-12.6 mL/m2, P=.07). EMT-S and EMT-L were significantly larger in the AF recurrence group (131.4+/-20.9 vs 116.3+/-15.5 ms, P=.005, and 152.2+/-15.7 vs 128.9+/-13.8 ms, P<.001, respectively), but not EMT-T. EMT-S and EMT-L were related to LA volume index (r=.36, P=.008, and r=.33, P=.02, respectively). On multivariate logistic regression analysis, only EMT-L was an independent predictor of identifying patients who remained in SR (P<.001), and the sensitivity and specificity for the prediction of 6-month maintenance of restored SR were 82.6% and 83.3% using a cutoff value of EMT-L<or=138.0 ms (odds ratio, 0.862; 95% confidence interval, 0.788-0.942; P=.001).</AbstractText>LA EMT was significantly prolonged in patients with recurring AF, indicating significantly depressed atrial conduction in enlarged LA, and can predict 6-month maintenance of SR after electrical cardioversion.</AbstractText>Copyright (c) 2010 American Society of Echocardiography. Published by Mosby, Inc. All rights reserved.</CopyrightInformation> |
5,883 | [Cardiac manifestations of patients with mitochondrial disease]. | To analyze the cardiac manifestations of mitochondriopathy patients.</AbstractText>We retrospectively analyzed the clinical (Electrocardiogram, Holter monitoring, echocardiogram and laboratory examinations) and pathological data of 90 mitochondriopathy patients diagnosed within recent 20 years. The cardiac involvement data from these patients were summarized.</AbstractText>Hypertrophic cardiomyopathy was found in 2 patients and dilated cardiomyopathy in 3 patients Mitochondriopathy diagnosis was made in 1 patient two years after heart transplantation due to heart failure resulting from previously diagnosed hypertrophic cardiomyopathy with noncompaction. The prevalence of cardiomyopathy is 5.6% (5/90). The prevalence of various arrhythmias was 22.2% (20/90). Four patients received permanent pacemaker because of Adams-Stokes attack or bradyarrhythmias (mitochondriopathy diagnosis was made 1-3 years post pacemaker implantation in 3 cases). History of syncope, respiratory failure, RBBB, atrial fibrillation and episodic ventricular tachyarrhythmias were presented in 1 patient with mitochondriopathy, another mitochondriopathy patient developed atrial tachyarrhythmias. Arrhythmia were present in 14 mitochondriopathy patients including RBBB, bifascicular block, intraventricular block, Wolff-Parkinson-White syndrome and short PR interval syndrome. The mtDNA 3243A-G mutation was detected in 8 patients.</AbstractText>Incidence of cardiomyopathy, heart failure and severe arrhythmias is high in patients with mitochondriopathy. Therefore, young cardiomyopathy patients with severe conduction block disorders should undergo relevant etiologic and genetic screening for mitochondriopathy and patients with diagnosed mitochondriopathy should regularly receive electrocardiogram and echocardiography examinations for possible cardiac involvement.</AbstractText> |
5,884 | [Efficacy of cardiac resynchronization therapy for patients with refractory congestive heart failure]. | To observe the efficacy of cardiac resynchronization therapy for patients with refractory congestive heart failure.</AbstractText>Thirty-one patients with refractory congestive heart failure received cardiac resynchronization therapy. Before operation, all patients received standard drug therapy (28 cases) or integrated with CRRT (3 cases). Coronary sinus and its branches were shown by direct angiography with hollow angiographic catheter (11 cases) and by balloon angiographic catheter (20 cases). Left ventricle and right ventricle electrodes were implanted to 3 patients with atrial fibrillation, 4 patients with paroxysmal ventricular tachycardia or ventricular fibrillation received CRT-D implantation. electrocardiogram, 24 hours Holter, echocardiography and physical clinical examinations were made at baseline, 6, 12, 18 and 24 months post resynchronization therapy.</AbstractText>Pacemakers were successfully implanted in all 31 patients. One patient implanted with CRT-D died of multiple organ failure on third day after operation, 1 patient suffered sudden cardiac death 5 months after therapy and 2 patients were lost to fellow up 6 and 12 months after operation, respectively. Results from the remaining 27 patients showed that QRS duration was significantly decreased (153 +/- 8.4 at baseline vs. 132 +/- 9.8 at 24 months follow up) and cardiac function significantly improved (LVEF 0.29 +/- 0.10 at baseline vs. 0.41 +/- 0.11 at 24 months follow up, P < 0.05 vs. baseline) during follow up compared to baseline. Malignant ventricular arrhythmia occurred in 3 patients with CRT-D and successfully terminated and converted to sinus rhythm.</AbstractText>Cardiac resynchronization therapy could improve cardiac function for patients with refractory congestive heart failure. CRT-D can effectively terminate the malignant ventricular arrhythmia.</AbstractText> |
5,885 | Low-dose amiodarone for the prevention of atrial fibrillation after coronary artery bypass grafting in patients older than 70 years. | Atrial fibrillation (AF) is one of the most common arrhythmia after coronary artery bypass grafting (CABG), which not only increases the suffering of the patients, but also prolongs hospital stay and enhances cost of care, especially for patients older than 70 years. This study was designed to evaluate the efficacy and safety of low-dose amiodarone in the prevention of AF after CABG, especially for the elderly.</AbstractText>Two hundred and ten senile patients undergoing off-pump CABG were included in this prospective, randomized, double-blind and placebo controlled study. Patients were given 10 mg/kg of amiodarone (low-dose amiodarone group, n = 100) or placebo (control group, n = 110) daily for 7 days before surgery and followed by 200 mg of amiodarone or placebo daily for 10 days postoperatively.</AbstractText>Postoperative AF occurred in 16 patients (16%) receiving amiodarone and in 36 (37.7%) patients receiving placebo (P = 0.006). AF occurred at (58.13 +/- 16.63) hours after CABG in the low-dose amiodarone group and at (45.03 +/- 17.40) hours in the control group (P = 0.018). The maximum ventricular rate during AF was significantly slower in the low-dose amiodarone group ((121.42 +/- 28.91) beats/min) than in the control group ((134.11 +/- 30.57) beats/min, P = 0.036). The duration of AF was (10.92 +/- 9.56) hours for the low-dose amiodarone group compared with (14.81 +/- 10.37) hours for the control group (P = 0.002). The postoperative left ventricular ejection fraction (LVEF) was significantly improved in the low-dose amiodarone group (from (59.9 +/- 10.3)% to (63.4 +/- 11.4)%, P = 0.001), and significantly higher compared with the control group ((58.5 +/- 10.7)%, P = 0.002). Both groups had a similar incidence of complication other than rhythm disturbances (12.0% vs 16.4%, P = 0.368). The low-dose amiodarone group patients had shorter hospital stays ((11.8 +/- 3.2) days vs (13.8 +/- 4.7) days, P = 0.001) and lower cost of care (RMB (79 115 +/- 16 673) Yuan vs RMB (84 997 +/- 21 587) Yuan, P = 0.031) than that of control group patients. The in-hospital mortality was not significantly different between the two groups (1.0% vs 0.9%, P = 0.946).</AbstractText>Perioperative low-dose oral amiodarone appeared to be cost-effective in the prevention and delay of new-onset postoperative AF in aged patients. It significantly reduced ventricular rate and duration of AF after CABG, decreased hospital cost and stay, as well as promoted the amelioration of left ventricular systolic function. Furthermore, low-dose amiodarone was safe to use and well tolerated with low toxic and side effects, and did not increase the risk of complications and mortality. It is proved to be a first-line therapy and as routine prophylaxis for AF after CABG, especially for elderly patients complicated with left ventricular dysfunction.</AbstractText> |
5,886 | Survival after prolonged resuscitation with 99 defibrillations due to Torsade De Pointes cardiac electrical storm: a case report. | A 48-year-old previously healthy woman suffered witnessed cardiac arrest in hospital. She achieved return of spontaneous circulation and was transferred to the intensive care unit. During the following 3 hours, she suffered a cardiac electrical storm with 98 episodes of Torsade de Pointes ventricular tachycardia rapidly degenerating to ventricular fibrillation. She was converted with a total of 99 defibrillations. There was no response to the use of any recommended anti arrhythmic drugs. However, the use of bretylium surprisingly stabilized her heart rhythm and facilitated placing of a temporary pacemaker. Overdrive pacing prevented further arrhythmias and was life saving. A number of beneficial factors may have contributed to the good neurological outcome. Further investigations gave no explanation for her cardiac electrical storm. |
5,887 | Perventricular closure of a large ventricular septal defect in congenitally corrected transposition of the great arteries. | We report the case of a 30 year-old male with congenitally corrected transposition of the great arteries, atrial, and ventricular septal defects (VSD), and pulmonary stenosis. He previously underwent three palliative surgical procedures before undergoing intracardiac repair at age 20 with a left ventricular to pulmonary artery (LV-PA) conduit, VSD closure, and replacement of the systemic atrioventricular valve. A residual VSD was noted postoperatively. He did well for approximately 10 years when he started becoming more breathless with daily activities and was noted to have a resting room air oxygen saturation of 85%. Despite increased diuretic therapy he continued to deteriorate and was ultimately admitted to the hospital in florid right and left heart failure with recurrent atrial fibrillation. Catheterization revealed pulmonary hypertension (pulmonary artery pressure = 80/17 mm Hg), moderate conduit stenosis, severe pulmonic regurgitation, and oxygen saturation of 75%. Calculated shunt fraction (Qp : Qs) was 1.3:1. He was referred for surgical intervention, specifically, LV-PA conduit replacement, oversewing of the pulmonic valve, VSD closure, and pacemaker placement. Intraoperatively, the VSD could not be closed despite multiple attempts through various approaches. Therefore, perventricular VSD closure using two Amplatzer septal occluders (AGA Medical, Golden Valley, MN) was performed in the operating room with the chest open off cardiopulmonary bypass. Following deployment, the residual shunt was small and the inferior vena cava-to-pulmonary artery saturation step-up was only 4%. The left ventricular systolic pressure decreased to one half systemic. This case highlights the utility and efficacy of a hybrid approach in the treatment of complex congenital heart disease. |
5,888 | Long-term follow up of secundum atrial septal defect closure with the amplatzer septal occluder. | During the past 15 years, closure of a secundum atrial septal defect (ASD) has moved from a surgical to a percutaneous transcatheter approach. Few long-term studies of the efficacy and safety of closure of an ASD by an Amplatzer septal occluder (ASO) exist.</AbstractText>To examine the long-term results of secundum ASD closure using the ASO, data on 94 patients who underwent secundum ASD closure with the ASO between 1998 and 2002 were available and reviewed. Data regarding residual shunt, chest pain, palpitations, arrhythmias, headaches, transient ischemic attacks, cerebrovascular accidents, and mortality were collected.</AbstractText>Seven (7.4%) subjects had residual shunts immediately following ASO placement. During follow-up, 4 residual shunts closed for a complete closure rate of 97%. Eighteen (19%) patients reported chest pain during the follow-up period. Twenty-three patients (24%) reported palpitations during the follow up period, 7 were documented arrhythmias, including supraventricular tachycardia, atrial fibrillation, and premature ventricular beats. Migraine headaches were new-onset in 4 patients. Migraine cessation occurred in 2 patients after secundum ASD closure. One child died from a cerebral vascular event 18 months following device placement. Only 1 patient developed mild aortic insufficiency.</AbstractText>These data indicate that for up to 120 months of patient follow-up, the ASO continues to be a safe device. Residual shunts and arrhythmias have low incidence post-ASO placement. Given the mortality in one high-risk patient, further investigation into anti-platelet therapy after device placement is warranted.</AbstractText> |
5,889 | [Specific features of cardiac insufficiency in elderly patients with chronic renal disease]. | To evaluate clinical features of chronic cardiac insufficiency (CCI) in elderly patients with renal dysfunction.</AbstractText>260 patents (143 men and 117 women) aged above 60 (mean 68.7 +/- 6.6) yr with I-IV FC CCI. 25 patients had hypertensive disease (HD), 30 coronary heart disease (CHD), 205 HD+CHD. Glomerular filtration rate (GFR) was estimated using MDRD formula.</AbstractText>Chronic renal disease (CRD) with GFR reduced below 60 ml/min/1.73 m2 was diagnosed in 126 (48.5%) patients. Its severity was not significantly different between patients with and without CCI. (2.3 +/- 0.7 and 2.1 +/- 0.7 respectively, p = 0.13). The entire study group was dominated by men, the CCI group by women. Atrial fibrillation (AF) was diagnosed in 25.8% of the patients with CI + CRD. Multivariate regression analysis revealed independent correlation of AF with CCI FC (p = 0.02) and GFR (p = 0.2). CCI patients with CRD had higher frequency of mitral regurgitation (MR) than without CRD. Occurrence of MR correlated with age (p < 0.001) and GFR (p < 0.001).</AbstractText>1. Renal dysfunction occurred in 48.55% of elderly patients with CCI. 2. A distinctive clinical feature of CCI + CRD in elderly patients is frequent development of AF and MR. 3. CCI + CRD is more frequent in women and CCI without CRD in men.</AbstractText> |
5,890 | Ensuring the continuity of care of cardiorespiratory diseases at home. Monitoring equipment and medical data exchange over semantically annotated web services. | A significant portion of care related to cardiorespiratory diseases is provided at home, usually but not exclusively, after the discharge of a patient from hospital. It is the purpose of the present study to present the technical means which we have developed, in order to support the adaptation of the continuity of care of cardiorespiratory diseases at home.</AbstractText>We have developed an integrated system that includes: first, a prototype laptop-based portable monitoring system that comprises low-cost commercially available components, which enable the periodical or continuous monitoring of vital signs at home; second, software supporting medical decision-making related to tachycardia and ventricular fibrillation, as well as fuzzy-rules-based software supporting home-ventilation optimization; third, a typical continuity of care record (CCR) adapted to support also the creation of a homecare plan; and finally, a prototype ontology, based upon the HL7 clinical document architecture (CDA), serving as basis for the development of semantically annotated web services that allow for the exchange and retrieval of homecare information.</AbstractText>The flexible design and the adaptable data-exchange mechanism of the developed system result in a useful and standard-compliant tool, for cardiorespiratory disease-related homecare.</AbstractText>The ongoing laboratory testing of the system shows that it is able to contribute to an effective and low-cost package solution, supporting patient supervision and treatment. Furthermore, semantic web technologies prove to be the perfect solution for both the conceptualization of a continuity of care data exchange procedure and for the integration of the structured medical data.</AbstractText> |
5,891 | Left atrial strain and strain rate in patients with paroxysmal and persistent atrial fibrillation: relationship to left atrial structural remodeling detected by delayed-enhancement MRI. | Atrial fibrillation (AF) is a progressive condition that begins with hemodynamic and/or structural changes in the left atrium (LA) and evolves through paroxysmal and persistent stages. Because of limitations with current noninvasive imaging techniques, the relationship between LA structure and function is not well understood.</AbstractText>Sixty-five patients (age, 61.2+/-14.2 years; 67% men) with paroxysmal (44%) or persistent (56%) AF underwent 3D delayed-enhancement MRI. Segmentation of the LA wall was performed and degree of enhancement (fibrosis) was determined using a semiautomated quantification algorithm. Two-dimensional echocardiography and longitudinal LA strain and strain rate during ventricular systole with velocity vector imaging were obtained. Mean fibrosis was 17.8+/-14.5%. Log-transformed fibrosis values correlated inversely with LA midlateral strain (r=-0.5, P=0.003) and strain rate (r=-0.4, P<0.005). Patients with persistent AF as compared with paroxysmal AF had more fibrosis (22+/-17% versus 14+/-9%, P=0.04) and lower midseptal (27+/-14% versus 38+/-16%, P=0.01) and midlateral (35+/-16% versus 45+/-14% P=0.03) strains. Multivariable stepwise regression showed that midlateral strain (r=-0.5, P=0.006) and strain rate (r=-0.4, P=0.01) inversely predicted the extent of fibrosis independent of other echocardiographic parameters and the rhythm during imaging.</AbstractText>LA wall fibrosis by delayed-enhancement MRI is inversely related to LA strain and strain rate, and these are related to the AF burden. Echocardiographic assessment of LA structural and functional remodeling is quick and feasible and may be helpful in predicting outcomes in AF.</AbstractText> |
5,892 | Right coronary artery occlusion during RF ablation of typical atrial flutter. | Right coronary artery (RCA) occlusion and acute myocardial infarction are rare during radiofrequency (RF) ablation of the cavotricuspid isthmus. Ventricular fibrillation (VF) or cardiac arrest in the periprocedural period may be the initial or only clinical manifestation. Septal or lateral RF delivery may increase the risk. We report 2 cases of RCA occlusion during ablation of typical atrial flutter (AFL). Angiographic and anatomical correlations are illustrated. One patient was ablated with a septal approach, the other with a lateral approach, and in each instance the RCA occluded near the ablative lesions. If septal or lateral ablation lines are contemplated during ablation of isthmus-dependent atrial flutter, fluoroscopic or electroanatomic confirmation of catheter position is pivotal. Smaller tipped catheters, energy titration (to minimally effective dose), saline irrigation, or cryoablation should also be considered to help avoid this serious complication. |
5,893 | Plasma NT-proANP in patients with persistent atrial fibrillation who underwent successful cardioversion. | Atrial fibrillation (AF) decreases quality of life and significantly increases risk of stroke, congestive heart failure and death. Atrial overload and stretch also result in increased production of natriuretic peptide type A (ANP). The biologically inactive prohormone NT-proANP is released to plasma in the same amounts as ANP but it has higher levels in the blood due to decreased degradation in vivo. In vitro degradation is also slower and NT-proANP may be an interesting alternative for ANP.</AbstractText>To evaluate NT-proANP plasma concentration in patients with persistent AF following successful cardioversion.</AbstractText>The study group consisted of 43 patients with persistent AF and normal left ventricular systolic function, who underwent successful electrical cardioversion (EC). The control group comprised 20 patients with sinus rhythm without a history of AF. Blood samples were collected twice, during visits 24 h before and after EC. All patients were also examined 30 days after the sinus rhythm recovery. The NT-proANP concentration was measured using an immunochemical method (ELISA).</AbstractText>Plasma NT-proANP concentration was significantly increased in patients with persistent AF compared to the control group (4.8 +/- 2.9 vs. 2.8 +/- 1.2 nmol/l, p = 0.004). Plasma NT-proANP level decreased significantly after successful cardioversion (to 3.2 +/- 2.4 nmol/l; p < 0.0001). There was no correlation between the baseline NT-proANP concentration and sinus rhythm maintenance during 30 days after EC.</AbstractText>Plasma NT-proANP concentration is higher in patients with persistent AF and normal left ventricular systolic function than in patients without arrhythmia. Sinus rhythm recovery due to EC leads to a decrease of plasma NT-proANP. The baseline NT-proANP level has no prognostic value for prediction of sinus rhythm maintenance during 30 days after EC.</AbstractText> |
5,894 | Availability of automated external defibrillators in the city of Warsaw - status for May 2009. | The most frequent cause of sudden cardiac arrest (SCA) is ventricular fibrillation and ventricular tachycardia. Despite many efforts the prognosis in this patient group is poor. According to the European Resuscitation Council (ERC) recommendations, early defibrillation, preferably in the first 3-5 min, is a key link in the Chain of Survival after SCA. With an increasing number of available automated external defibrillators (AED) time from SCA to defibrillation may be reduced, thus resulting in the improvement of patients' prognosis. Therefore, the ERC recommends providing AED in public locations with a high incidence of cardiac arrests.</AbstractText>Estimation of the availability of AED in the city of Warsaw.</AbstractText>Automated external defibrillators were identified according to the information from the City Hall, public services, foundations, companies and own research and knowledge. The AED presence was confirmed by phone at the potential locations and random locations were visited.</AbstractText>By 15 May 2009, 117 AED had been reported in 83 points in the city of Warsaw. The number of AED was the highest in the Sródmieście (29) and Włochy (28) districts. On average, there was one AED per 14 706 citizens (0.68 per 10,000 citizens) and per 4.24 km(2) (2.26 per 10 km(2)). The highest ratio of the number of AED per 10,000 citizens was observed in the Włochy (7.06) and Sródmieście (2.25) districts, the lowest - in the Targówek (0.16), Wawer (0.15) and Bemowo (0.09) districts. The highest ratio of the number of AED per 10 km(2) were in the Sródmieście (18.63), Włochy (9.78) and Zoliborz (5.9) districts, the lowest - in the Wilanów (0.27) and Wawer (0.13) districts.</AbstractText>The number of AED in the city of Warsaw should be increased, additional demonstrations of AED proper usage and AED promotion should be organised. It is necessary to provide easy access to the devices. Significant differences in the number of AED can be observed between the districts. Neither authorities nor public services are aware of the number of AED in the city of Warsaw.</AbstractText> |
5,895 | Hyperbaric oxygen preconditioning improves myocardial function, reduces length of intensive care stay, and limits complications post coronary artery bypass graft surgery. | The objective of this study was to determine whether preconditioning coronary artery disease (CAD) patients with HBO(2) prior to first-time elective on-pump cardiopulmonary bypass (CPB) coronary artery bypass graft surgery (CABG) leads to improved myocardial left ventricular stroke work (LVSW) post CABG. The primary end point of this study was to demonstrate that preconditioning CAD patients with HBO(2) prior to on-pump CPB CABG leads to a statistically significant (P<.05) improvement in myocardial LVSW 24 h post CABG.</AbstractText>This randomised control study consisted of 81 (control group=40; HBO(2) group=41) patients who had CABG using CPB. Only the HBO(2) group received HBO(2) preconditioning for two 30-min intervals separated 5 min apart. HBO(2) treatment consisted of 100% oxygen at 2.4 ATA. Pulmonary artery catheters were used to obtain perioperative hemodynamic measurements. All routine perioperative clinical outcomes were recorded. Venous blood was taken pre HBO(2), post HBO(2) (HBO(2) group only), and during the perioperative period for analysis of troponin T.</AbstractText>Prior to CPB, the HBO(2) group had significantly lower pulmonary vascular resistance (P=.03). Post CPB, the HBO(2) group had increased stroke volume (P=.01) and LVSW (P=.005). Following CABG, there was a smaller rise in troponin T in HBO(2) group suggesting that HBO(2) preconditioning prior to CABG leads to less postoperative myocardial injury. Post CABG, patients in the HBO(2) group had an 18% (P=.05) reduction in length of stay in the intensive care unit (ICU). Intraoperatively, the HBO(2) group had a 57% reduction in intraoperative blood loss (P=.02). Postoperatively, the HBO(2) group had a reduction in blood loss (11.6%), blood transfusion (34%), low cardiac output syndrome (10.4%), inotrope use (8%), atrial fibrillation (11%), pulmonary complications (12.7%), and wound infections (7.6%). Patients in the HBO(2) group saved US$116.49 per ICU hour.</AbstractText>This study met its primary end point and demonstrated that preconditioning CAD patients with HBO(2) prior to on-pump CPB CABG was capable of improving LVSW. Additionally, this study also showed that HBO(2) preconditioning prior to CABG reduced myocardial injury, intraoperative blood loss, ICU length of stay, postoperative complications, and saved on cost, post CABG.</AbstractText> |
5,896 | Attenuated recovery of heart rate turbulence early after myocardial infarction identifies patients at high risk for fatal or near-fatal arrhythmic events. | Autonomic dysfunction tends to improve over time after acute myocardial infarction (MI), but the clinical significance of autonomic remodeling is not well known.</AbstractText>The purpose of this study was to test the hypothesis that the amount of recovery of autonomic function early after MI is associated with a risk for serious arrhythmias.</AbstractText>The prognostic significance of autonomic remodeling after MI was assessed in one post-MI cohort [Cardiac Arrhythmia and Risk Stratification after Myocardial Infarction (CARISMA)] and validated in a second cohort [Risk Estimation After Infarction, Noninvasive Evaluation (REFINE)]. Changes in heart rate variability (DeltaHRV) and heart rate turbulence (DeltaHRT) were measured from 24-hour ECG recordings performed early (5-21 days) and later (6 weeks) after MI in CARISMA (n = 312). DeltaHRV and DeltaHRT were similarly measured from early (2-4 weeks) and later (10-14 weeks) post-MI recordings in REFINE (n = 322).</AbstractText>HRV and HRT increased over time in both cohorts. Attenuated recovery of autonomic function, defined as DeltaHRT slope <2.0 ms/RR, was associated with a 9.4-fold (95% confidence interval 1.2-71.6; P = .03) higher risk of ECG-documented sustained ventricular tachycardia or ventricular fibrillation in CARISMA and a 7.0-fold (95% confidence interval 1.6-29.6; P = .009) higher risk of fatal or near-fatal events in REFINE. Changes in HRV and HRT were not predictive of nonarrhythmic death in either cohort.</AbstractText>Attenuated recovery of autonomic function early after MI consistently predicts a higher risk of fatal or near-fatal arrhythmic events. A lack of improvement in HRT early after MI appears to be a specific marker for serious arrhythmic events.</AbstractText> |
5,897 | Atrial electrophysiological and structural remodeling in high-risk patients with Brugada syndrome: assessment with electrophysiology and echocardiography. | Atrial fibrillation (AF) often occurs in Brugada syndrome (BrS), and BrS patients with spontaneous AF often experience ventricular fibrillation (VF) attacks. Atrial vulnerability providing a substrate for AF is known to be enhanced in BrS, but there are no data on atrial structural attributes.</AbstractText>The objective of this study was to assess atrial electrophysiological and structural characteristics in BrS and their relationships with gene mutations.</AbstractText>We studied 57 patients with BrS. Intra-atrial conduction time (CT) was defined as the interval from the stimulus at the high right atrium to atrial deflection at the distal portion of the coronary sinus. Left atrial volume index (LAVI) was measured by the modified Simpson method at left ventricular end-systole using echocardiography. SCN5A mutations were analyzed in all patients.</AbstractText>In patients with documented VF, spontaneous AF frequently occurred and prolonged CT and increased LAVI were observed compared with those in patients without VF (all P < .05; LAVI: 22 +/- 5 vs. 32 +/- 7 ml/m(2)). Even among patients without AF, CT and LAVI were still increased in patients with VF (all P < .05; LAVI: 22 +/- 5 vs. 29 +/- 5 ml/m(2)). The presence of SCN5A mutation was associated with prolonged CT (P < .05) and increased LAVI (P < .01), but not with arrhythmic episodes.</AbstractText>Both atrial vulnerability and structural remodeling are enhanced in high-risk patients with BrS, even in those without AF. These morphological characteristics suggest that BrS is a form of genetic myocardial disease.</AbstractText> |
5,898 | In-flight automated external defibrillator use and consultation patterns. | Limited information exists about the in-flight use and outcomes associated with automated external defibrillators (AEDs) on commercial airlines.</AbstractText>To describe the characteristics and outcomes of AED use during in-flight emergencies including in-flight cardiac arrest and the associated ground medical consultation patterns.</AbstractText>We collected cases of AED use that were self-reported to an airline consultation service from three U.S. airlines between May 2004 and March 2009. We reviewed all available data files, related consultation forms, and recordings. For each case, demographics, initial rhythm, shock delivery/success, survival to admission, and ground medical consultation use were obtained. Success was defined as the return of a perfusing rhythm. Initial rhythms were classified as sinus, heart block, supraventricular tachycardia (SVT), atrial fibrillation/flutter, asystole, pulseless electrical activity (PEA), and ventricular fibrillation (VF)/ventricular tachycardia (VT).</AbstractText>There were a total of 169 AED applications with 40 cardiac arrests. The mean patient ages were 58 years (standard deviation [SD] 15) and 63 years (SD 12), respectively; both populations were 64% male. AEDs were applied for monitoring in 129 (76%) cases with the following initial rhythms: sinus, 114 (88%); atrial fibrillation/flutter, seven (5%); complete heart block, four (3%); and SVT, four (3%). Presenting rhythms among the cardiac arrest population were as follows: asystole, 16 (40%); VF/VT, 10 (25%); and PEA, 14 (35%). Fourteen patients were defibrillated, including nine of the 10 patients with initial VF/VT and five for the presence of VF/VT after resuscitation for initial PEA/asystole. Defibrillation was advised but not performed in the remaining case of initial VF/VT, and no medical consultation was obtained. All five successful defibrillations occurred in patients with initial VF/VT. There were six (15%; 95% confidence interval [CI] 3-27%) survivors, with five survivals occurring after successful defibrillation for initial VF/VT and one with return of a perfusing rhythm after cardiopulmonary resuscitation (CPR) for a junctional rhythm. Survival in those with VF/VT was five of 10 (50%; 95% CI 14-86%). Medications were delivered in two cases. The median time to first shock was 19 seconds (interquartile range [IQR] 12-24 seconds) after AED application. Medical consultation was obtained in 42 (33%) of the 129 AED monitoring cases and 14 (35%) of the 40 cardiac arrest cases.</AbstractText>Use of AEDs resulted in 50% survival among those with VF/VT in flight and 15% overall survival for cardiac arrest. Survival is poor among patients presenting with nonshockable rhythms. AEDs are used extensively for in-flight monitoring, with significant rhythms identified. Ground medical consultation is sought in only one-third of AED uses and cardiac arrests.</AbstractText> |
5,899 | [Defibrillation efficacy of a newly developed automated external defibrillator in a swine ventricular tachycardia/fibrillation model]. | The aim of this study was to evaluate the recognition and defibrillation efficiency of a newly developed automated external defibrillator (AED).</AbstractText>Ventricular tachycardia (VT)/ventricular fibrillation (VF) was induced by alternating current (50 Hz) through an electrode placed on apex of right ventricle in 23 anesthetized swine and recorded, recognized and defibrillated by a newly developed AED.</AbstractText>A total of 96 VF was induced and 145 defibrillations were recorded. We analyzed available 167 electrocardiosignal with a total length of 103,740 seconds. The accuracy, sensitivity and the specificity of the AED on VT/VF recognition are 99.5%, 98.2% and 99.6%, respectively. The success rate of defibrillation was 33.4% which increased in proportion to defibrillation energy. The defibrillation threshold of energy is 29.10-116.91 (78.75 +/- 35.64) J, the defibrillation threshold of electric quantity is (0.11 +/- 0.04) C and the defibrillation threshold of voltage is (1216.67 +/- 260.87) V.</AbstractText>This newly developed AED has high sensitivity and the specificity on recognizing VT/VF. The lower success rate of defibrillation of this AED is associated with the low defibrillation energy during defibrillation which needs to be improved on further development.</AbstractText> |
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