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6,700 | Atrial fibrillation and heart failure in cardiology practice: reciprocal impact and combined management from the perspective of atrial fibrillation: results of the Euro Heart Survey on atrial fibrillation. | Our aim was to identify shortcomings in the management of patients with both atrial fibrillation (AF) and heart failure (HF).</AbstractText>AF and HF often coincide in cardiology practice, and they are known to worsen each other's prognosis, but little is known about the quality of care of this combination.</AbstractText>In the observational Euro Heart Survey on AF, 5,333 AF patients were enrolled in 182 centers across 35 European Society of Cardiology member countries in 2003 and 2004. A follow-up survey was performed after 1 year.</AbstractText>At baseline, 1,816 patients (34%) had HF. Recommended therapy for HF with left ventricular systolic dysfunction (LVSD) with a beta-blocker and either an angiotensin-converting enzyme inhibitor (ACEI) or angiotensin II receptor blocker was prescribed in 40% of HF patients, while 29% received the recommended drug therapy for both LVSD-HF and AF, consisting of the combination of a beta-blocker, either ACEI or angiotensin II receptor blocker, and oral anticoagulation. Rate control was insufficient with 40% of all HF patients with permanent AF having a heart rate < or =80 beats/min. In the total cohort, HF patients had a higher risk for mortality (9.5% vs. 3.3%; p < 0.001), (progression of) HF (24.8% vs. 5.0%; p < 0.001), and AF progression (35% vs. 19%; p < 0.001) during 1-year follow-up. Of all recommended drugs for AF and LVSD-HF, only ACEI prescription was associated with improved survival during 1-year follow-up (odds ratio: 0.51 [95% confidence interval: 0.31 to 0.85]; p = 0.011).</AbstractText>The prescription rate of guideline-recommended drug therapy for AF and LVSD-HF is low. Randomized controlled trials targeting this highly prevalent subgroup with AF and HF are warranted.</AbstractText> |
6,701 | Accelerated idioventricular rhythm associated with desflurane anesthesia :A case report. | Accelerated idioventricular rhythm is defined as a ventricular rhythm of 60-100 beats per minute or a ventricular tachycardia that does nor exceed 120 beats per minutes. Although, it rarely converts to a fatal arrhythmia like ventricular fibrillation, it needs to be differentiated from AIVR, which is from another origin. AIVR may occur due to ischemic heart disease (ST elevated myocardial infarction), cardiomyopathy, rheumatic fever and digitalis intoxication. We report here on a case of AIVR that was related to desflurane administration. |
6,702 | [Poisoning with antidepressants]. | Intoxications with medications are among the most frequent diagnoses in patients admitted to medical emergency departments and intensive care units. Due to their particular toxicity tricyclic antidepressants play an important role despite a decreasing incidence. Tricyclic antidepressant toxicity includes an inhibition of myocardial excitability, central (sedation, seizures) and peripheral anticholinergic signs, and arterial hypotension. Cardiac arrhythmia including ventricular tachycardia and fibrillation, sustained seizures and severe central anticholinergic symptoms such as agitation, delirium, and hyperthermia, are life threatening. Important treatment options include gastrointestinal decontamination with oral single-dose activated charcoal within 1-2 hours post ingestion, and antidotal therapy with boluses of sodium bicarbonate for cardiotoxicity. The selective serotonin reuptake inhibitors (SSRI) and the atypical antidepressants are far less toxic than tricyclics. They may lead to serotonin toxicity (serotonin syndrome). |
6,703 | Antifibrillatory agents and potassium channels in the atria: pore block versus channel trafficking. | Atrial fibrillation (AF) is the most common cardiac arrhythmia. The preferred therapy for AF is sustained sinus rhythm control; however, the efficacy of currently used antiarrythmic drugs is limited by adverse side effects resulting from both a lack of ion channel selectivity and nonspecific ventricular activity. The role of the voltage-gated potassium channels in atrial myocyte repolarization and the subsequent control of action potential duration renders them attractive targets for antiarrhythmic drugs in the treatment of AF. Conventional antiarrhythmic drugs generally target the ion permeability of potassium channels. This review discusses the limitations of this traditional approach and introduces, as a novel paradigm for antiarrhythmic pharmacology, the decrease of ion channel cell surface density through the modulation of ion channel trafficking pathways. |
6,704 | Selective treatment algorithm for mitral valve annuloplasty in nonischemic functional mitral regurgitation. | The success rate of mitral annuloplasty (MA) for functional mitral regurgitation (FMR) varies. This study evaluated the effectiveness of this procedure in nonischemic dilated cardiomyopathy (DCM) patients after a selective treatment protocol was followed.</AbstractText>This study analyzed 42 patients with nonischemic DCM and FMR (mean regurgitation grade, 3.6 +/- 0.3), aged a mean 56.5 +/- 15 years (range, 25 to 78 years), who underwent MA from April 2003 to December 2007. The analysis excluded patients with coronary artery disease, or mitral leaflets or subvalvular pathologies. All patients had taken maximal medications for at least 3 months and were still in New York Heart Association (NYHA) functional class III to IV (mean, 3.2 +/- 0.4). Mean ejection fraction (EF) was 31.4% +/- 12.9% (range, 8% to 58%), and left ventricular end-diastolic diameter (LVEDD) was 66.0 +/- 8.3 mm (range, 55 to 85 mm). Downsized Carpentier Physio ring (Carpentier-Edwards, Irvine, California) annuloplasty, mean size 26.3 +/- 2.3 (range, 24 to 30), was the preferred procedure. Concomitant procedures included 23 tricuspid valve repairs and 10 Maze operations for atrial fibrillation. Echocardiography was performed at early (<or=3 months; mean 1.6 +/- 1.5), short-term (6 to 12 months; mean 6.9 +/- 3.4), and midterm (>12 months; mean 29.5 +/- 13.4 months) follow-up. All late deaths and readmissions were recorded. One (2.4%) in-hospital death occurred due to low cardiac output. Follow-up was completed in 40 of 41 (97.6%) patients (mean duration, 31.9 +/- 16.1; range, 3.9 to 59.2 months). Eight (19.5%) patients were readmitted for heart failure, including 2 late MRs due to ring dehiscence and infective endocarditis. Three of 5 deaths during the follow-up period were attributed to cardiac death. Actuarial survival after 1 and 3 years was 88.9% and 79.2%, respectively. The number of patients treated with beta-blockers increased after operation, from 52.4% to 75.6% (P = .028). NYHA class decreased from 3.2 +/- 0.4 to 1.3 +/- 0.6 (P < .0001). Echo examination revealed left heart reverse remodeling and improved performance in all follow-up time frames.</AbstractText>This study shows that MA in patients with non-ischemic DCM and FMR is feasible and associated with reasonable short and long term outcomes.</AbstractText> |
6,705 | Prevalence and physiological predictors of sleep apnea in patients with heart failure and systolic dysfunction. | Previous studies reported high prevalences of obstructive and central sleep apnea (OSA and CSA, respectively) in patients with heart failure (HF). However, these preceded widespread use of beta-blockers and spironolactone that might have reduced their prevalences. We therefore determined, in patients with HF, prevalences and predictors of OSA and CSA and the influence of changes in HF therapy on prevalences.</AbstractText>A total of 218 HF patients with left ventricular ejection fraction (LVEF) <or=45% underwent sleep studies between 1997 and 2004 and were classified as having moderate to severe sleep apnea (apnea-hypopnea index >or=15 hours of sleep, either OSA or CSA), or mild to no sleep apnea. The prevalence of moderate to severe OSA was 26% and of CSA was 21%. Predictors of OSA were older age, male sex, and greater body mass index, and of CSA were older age, male sex, atrial fibrillation, hypocapnia, and diuretic use. Between 1997 and 2004, the prevalences of OSA and CSA did not change significantly (P(trend) =.460, P(trend) =.211, respectively) despite increased use of beta-blockers and spironolactone (P(trend) < .001, P(trend) < .001, respectively), and an increase in LVEF (P(trend)=.005).</AbstractText>OSA and CSA remain common in patients with HF, despite increases in beta-blocker and spironolactone use.</AbstractText> |
6,706 | Ventricular fibrillation induced by a radiofrequency energy delivery for idiopathic premature ventricular contractions arising from the left ventricular anterior papillary muscle. | A 73-year-old man with idiopathic premature ventricular contractions (PVCs) underwent electrophysiological testing. Left ventricular activation mapping revealed a focal mechanism of the PVCs with the earliest activation on the anterior papillary muscle (APM). Irrigated radiofrequency (RF) current delivered at that site induced a cluster of non-sustained ventricular tachycardia episodes with the same QRS morphology as the PVCs, followed by ventricular fibrillation (VF). The APM might have served as an abnormal automatic trigger and driver for the VF occurrence. Ventricular fibrillation may occur as a complication during RF catheter ablation of papillary muscle ventricular arrhythmias even if the clinical arrhythmia is limited to PVCs. |
6,707 | Cerebral metabolic rate of oxygen (CMRO2) in pig brain determined by PET after resuscitation from cardiac arrest. | To assess the regional vulnerability to ischemic damage and perfusion/metabolism mismatch of reperfused brain following restoration of spontaneous circulation (ROSC) after cardiac arrest.</AbstractText>We used positron emission tomography (PET) to map cerebral metabolic rate of oxygen (CMRO(2)), cerebral blood flow (CBF) and oxygen extraction fraction (OEF) in brain of young pigs at intervals after resuscitation from cardiac arrest. After obtaining baseline PET recordings, ventricular fibrillation of 10 min duration was induced, followed by mechanical closed-chest cardiopulmonary resuscitation (CPR) in conjunction with i.v. administration of 0.4 U/kg of vasopressin. After CPR, external defibrillatory shocks were applied to achieve restoration of spontaneous circulation (ROSC). CBF and CMRO(2) were mapped and voxelwise maps of OEF were calculated at times of 60, 180, and 300 min after ROSC.</AbstractText>There was hypoperfusion throughout the telencephalon at 60 min, with a return towards baseline values at 300 min. In contrast, there was progressively increasing CBF in cerebellum throughout the observation period. The magnitude of CMRO(2) decreased globally after ROSC, especially in cerebral cortex. The magnitude of OEF in cerebral cortex was 60% at baseline, tended to increase at 60 min after ROSC, and declined to 50% thereafter, thus suggesting transition to an ischemic state.</AbstractText>The cortical regions tended most vulnerable to the ischemic insult with an oligaemic pattern and a low CMRO(2) whereas the cerebellum instead showed a pattern of luxury perfusion.</AbstractText> |
6,708 | Regional prevalence and clinical benefit of implantable cardioverter defibrillators in Brugada syndrome. | Brugada syndrome (BS) is associated with an increased risk of sudden cardiac death (SCD) caused by ventricular tachyarrhythmia. Thus, implantable cardioverter defibrillators (ICD) became the main therapeutic option in these patients. We aimed to investigate the prevalence of BS in the Eastern Alps as well as the benefit of ICD therapy in this collective.</AbstractText>During physical examination before military service, 47,606 Austrian men were screened for Brugada ECG pattern. Furthermore, we followed 4491 patients with arrhythmia during the last two decades, of which 26 patients (20 male; age at diagnosis: 43.2 ± 11.6 years) revealed BS. Diagnosis was based on characteristic ECG either at rest (11 patients) or after provocation with Ajmaline (15 patients).</AbstractText>The nationwide screening revealed one individual with Brugada ECG (prevalence of 2.10/100,000 inhabitants). Prior to diagnosis of BS, syncope and SCD survival were observed in 7 and 4 patients, respectively; the remaining 15 patients were asymptomatic. ICD were implanted in 17 patients (15 male). Three asymptomatic patients received no ICD because no tachyarrhythmia was inducible on programmed stimulation. Six asymptomatic patients without family history of sudden death refused further evaluation. Mean ICD follow-up period was 57.0 ± 32.2 months. Two patients (11.7%) needed defibrillation therapy. Four patients (23.5%) received exclusively inappropriate shocks (three due to T-wave oversensing, one due to atrial fibrillation).</AbstractText>Brugada syndrome has a low prevalence in the Eastern alpine region. Patients with BS benefit from ICD implantation, but less frequently than anticipated. The problem of inappropriate ICD discharges is still of major concern.</AbstractText>Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
6,709 | Acute efficacy of combined therapy of carperitide and nicorandil for acute decompensated heart failure with left ventricular systolic dysfunction. | A 64-year-old woman was admitted to our hospital with acute decompensated heart failure (ADHF) and left ventricular systolic dysfunction. Initial treatment with carperitide (0.01 µg/kg/min) had little effect. Since she had a borderline systolic blood pressure (i.e., a systolic BP between 90 and 110 mm Hg) and atrial fibrillation with a rapid ventricular response, nicorandil (0.1 mg/kg/h) was added to carperitide. This combined therapy achieved rapid improvement of ADHF. To our knowledge, this is the first report of a patient with ADHF and borderline systolic blood pressure in whom the combination of carperitide and nicorandil was safe and effective. |
6,710 | Off-pump transapical mitral valve replacement. | Percutaneous valve replacement was recently introduced, and reports of early clinical experience have already been published. To date, this technique is limited to the replacement of pulmonary and aortic valves in a strictly selected group of patients. The aim of this study was to analyse a self-expanding valved stent for minimally invasive replacement of the mitral valve in animals.</AbstractText>A newly designed nitinol stent was specially designed for this experimental acute study. It comprised of a left ventricular tubular stent with star shaped left atrial anchoring springs and carried a trileaflet bovine pericardial valve. A polytetrafluoroethylene membrane was sutured to envelop the atrial springs and the outside of the ventricular stent. The ventricular anchoring system was the same as in our previously reported results with a similar mitral valved stent. Seven pigs underwent minimally invasive off-pump mitral valved stent implantation. This was performed through a lower mini-sternotomy and a standard transapical approach under transoesophageal echocardiographic (TEE) guidance was used.</AbstractText>The valved stent is fully retrievable and precise deployment and accurate adjustment of its intra-annular position is achievable to eliminate paravalvular leakage. The deployment time ranged from 127 to 255s and the blood loss from 70 to 220cc. One animal died of intractable ventricular fibrillation. Mitral regurgitation in all surviving animals was minimal (trace in 5/6 and mild in 1/6 during echo examination; on the contrast ventriculogram no mitral insufficiency was observed except in one documented as mild paravalvular regurgitation). These animals remained haemodynamically stable (6/6) and without TEE or ventriculographic changes for 1h.</AbstractText>Implantation of a tricuspid bovine pericardial valved stent in the mitral position is feasible in pigs through a transcatheter approach. This was possible through a smaller delivery system than previously reported. Additional studies are required to demonstrate long-term feasibility, durability, and heart function.</AbstractText> |
6,711 | Catheter ablation of fatal ventricular tachyarrhythmias storm in acute coronary syndrome--role of Purkinje fiber network. | Ventricular fibrillation (VF) or ventricular tachycardia (VT) storm is a life-threatening arrhythmia. Antiarrhythmic drugs (AADs) are not necessarily effective to rescue life from such conditions. Catheter ablation (CA) targeting triggering premature ventricular contractions (PVCs) of VF or VT that originates from Purkinje fiber network (PFN) is reported to be effective, especially in idiopathic patients. However, in condition of acute coronary syndrome (ACS), the efficacy of CA is not well understood. To clarify the usefulness of CA as an alternative way to AADs, we performed CA in four patients with VF or VT storm. The Purkinje potential was seen just before the myocardial ventricular wave during sinus rhythm that became more prominent and double components during the initiating PVC at the targeted area. Following CA, spontaneous episodes of VF or VT were no longer observed. CA is an efficacious way to bail out PFN-related VF or VT storm even in ACS. |
6,712 | Rapid ventricular pacing to optimize rotational angiography in atrial fibrillation ablation. | Conventional pulmonary vein (PV) angiography cannot precisely delineate the left atrium (LA)-PV anatomy, which is essential for the ablation of atrial fibrillation (AF). The aim of the study was to test the feasibility of a novel method of rotational angiography for the AF ablation.</AbstractText>Forty-one patients were enrolled in this study. CT scanning was performed in all patients before the procedure. Rotational angiography (rotating from right anterior oblique 55 degrees to left anterior oblique 55 degrees ) was performed before AF ablation. Rapid ventricular pacing (RVP, 300 ms) was carried out to reduce cardiac output while contrast medium was injected into the LA via a pigtail catheter. RVP was successfully performed in 36 (87.8%) patients. The ostia of all PVs and the LA appendage were visible in all these 36 cases. There was a good correlation in the PV ostial diameters as assessed by rotational angiography via RVP as compared to CT imaging (r (2) > 0.85).</AbstractText>Rotational angiography by RVP is able to delineate the LA-PV anatomy. There is a good correlation in the PV ostial diameters as assessed by rotational angiography via RVP and CT imaging. Rotational angiography by RVP is feasible during AF ablation.</AbstractText> |
6,713 | Cardiopulmonary resuscitation: outcome and its predictors among hospitalized adult patients in Pakistan. | Our aim was to study the outcomes and predictors of in-hospital cardiopulmonary resuscitation (CPR) among adult patients at a tertiary care centre in Pakistan.</AbstractText>We conducted a retrospective chart review of all adult patients (age > or =14 years), who underwent CPR following cardiac arrest, in a tertiary care hospital during a 5-year study period (June 1998 to June 2003). We excluded patients aged 14 years or less, those who were declared dead on arrival and patients with a "do not resuscitate" order. The 1- and 6-month follow-ups of discharged patients were also recorded.</AbstractText>We found 383 cases of adult in-hospital cardiac arrest that underwent CPR. Pulseless electrical activity was the most common initial rhythm (50%), followed by asystole (30%) and ventricular tachycardia/fibrillation (19%). Return of spontaneous circulation was achieved in 72% of patients with 42% surviving more than 24 h, and 19% survived to discharge from hospital. On follow-up, 14% and 12% were found to be alive at 1 and 6 months, respectively. Multivariable logistic regression identified three independent predictors of better outcome (survival >24 h): non-intubated status [adjusted odds ratio (aOR): 3.1, 95% confidence interval (CI): 1.6-6.0], location of cardiac arrest in emergency department (aOR: 18.9, 95% CI: 7.0-51.0) and shorter duration of CPR (aOR: 3.3, 95% CI: 1.9-5.5).</AbstractText>Outcome of CPR following in-hospital cardiac arrest in our setting is better than described in other series. Non-intubated status before arrest, cardiac arrest in the emergency department and shorter duration of CPR were independent predictors of good outcome.</AbstractText> |
6,714 | Treatment of ventricular arrhythmias in the elderly. | Underlying causes of ventricular tachycardia (VT) or complex ventricular arrhythmias (VA) should be treated if possible. Antiarrhythmic drugs should not be administered to treat asymptomatic individuals with complex VA and no heart disease. Beta-blockers are the only antiarrhythmic drugs that have been documented to reduce mortality in patients with VT or complex VA. Radiofrequency catheter ablation of VT has been beneficial in treating selected patients with arrhythmogenic foci of monomorphic VT. The automatic implantable cardioverter-defibrillator (AICD) is the most effective treatment for patients with life-threatening VT or ventricular fibrillation. Patients with AICDs should be treated with biventricular pacing, not with dual-chamber rate-responsive pacing at a rate of 70/min. Patients with AICDs should also be treated with beta-blockers, statins, and angiotensin-converting enzyme inhibitors or angiotensin blockers. |
6,715 | Tentacles: a novel device for exposing the heart for the insertion of left apical assist device cannulae. | The implantation of ventricular assist devices is a well-established procedure for the treatment of imminent heart failure. The exact positioning of the left ventricular apical inflow cannula is crucial, because inflow restrictions might occur when the cannula is placed too close to the interventricular septum or a papillary muscle. We report a novel technique using the Tentacles 3-point fixation device for the exposure of the left ventricular apex during ventricular fibrillation under cardiopulmonary bypass.</AbstractText>We used the Tentacles, a device originally designed for positioning the heart during off-pump coronary artery bypass grafting, for implantation of a biventricular Berlin Heart Excor in a 64-year-old man. The procedure was successful and echocardiographic examinations documented the exact placement of the left ventricular cannula.</AbstractText>Our new technique ensures a very precise insertion of apical cannulae, because the left ventricular shape and filling are not impaired.</AbstractText> |
6,716 | What should be the primary treatment in atrial fibrillation: ventricular rate control or sinus rhythm control with long-term anticoagulation? | Recent trials have favoured ventricular rate control in atrial fibrillation (AF) management, however the present study investigated whether the restoration and maintenance of sinus rhythm with long-term anticoagulation therapy was superior in terms of embolic events and death in 534 patients with an AF duration > 48 h. Patients were randomized and received sinus rhythm control with either aspirin (group 1) or warfarin (group 2), or they were given ventricular rate control (group 3). Cardioversion to sinus rhythm was attempted in 425 patients and was successful in 387 (91.1%) of them. After 3 years' follow-up there were 12, two and 15 embolic events in groups 1, 2 and 3 respectively (significant difference between groups 1 and 2, and 2 and 3) and overall mortalities were four, two and 12, respectively (significant difference between groups 2 and 3). It is concluded that patients with an AF duration > 48 h might benefit considerably from sinus rhythm restoration and long-term warfarin therapy in terms of embolic events and mortality. |
6,717 | Oral magnesium prophylaxis provides spontaneous resumption of cardiac rhythm in patients undergoing cardiac surgery. | Evidence is growing that magnesium supplementation in patients undergoing cardiac surgery is beneficial, however the best administration route has not been established. Previously, we showed that intra-operative direct flush infusion of magnesium into the aortic root before reperfusion was effective. The present study compared pre-operative oral administration of magnesium for 10 days with intra-operative flush infusion of magnesium for spontaneous resumption of cardiac rhythm and ventricular fibrillation in patients undergoing cardiac surgery with cardiopulmonary bypass (CBP). The rate of spontaneous resumption of cardiac rhythm, the number of shocks required for defibrillation, the energy required for defibrillation and the occurrence of post-CPB ventricular tachyarrhythmias were not significantly different between the groups. Serum magnesium levels were minimally increased following administration of magnesium but were within the normal range at all times in both groups. Oral administration of magnesium might provide my oprotective effects during cardiac surgery, but larger trials with a greater statistical power need to be carried out in order to show this. |
6,718 | Cardiac resynchronization therapy in NYHA class IV heart failure. | Clinical practice guidelines recommend cardiac resynchronization therapy (CRT) for ambulatory New York Heart Association (NYHA) class IV patients with a QRS duration >or= 120 ms and a left ventricular ejection fraction <or= 35%. Only two prospective, randomized trials have compared outcomes after CRT in NYHA class III and IV patients. CRT improved mortality, exercise capacity, and quality of life in class IV patients, but the 1-year mortality remained high. Patients in these trials were in sinus rhythm at randomization and most patients had a left bundle branch block. Less data are available for NYHA class IV patients with atrial fibrillation, right bundle branch block, and previous ventricular pacing. No prospective randomized data are available for the use of CRT as rescue therapy in inotrope-dependent patients, but several case series have reported promising results. It is likely that "rescue therapy" with CRT will be most beneficial when patients improve enough with CRT to allow reinstitution of angiotensin-converting enzyme inhibitors and beta blockers. |
6,719 | AED use in a passenger during a long-haul flight: repeated defibrillation with a successful outcome. | Sudden cardiac arrest is one of the leading causes of death, and early defibrillation of ventricular fibrillation (VF) is the single most important intervention for improving survival. The automated external defibrillator (AED) and the concept of public access defibrillation provide a solution to shorten defibrillation delays. Commercial aircraft create a unique environment for the use of the AED since an emergency medical service system (EMS) response is not available. We review published studies on this subject and describe the case of a passenger who developed VF during an intercontinental flight and was successfully resuscitated despite recurrent episodes of VF.</AbstractText>A 60-yr-old man developed VF during a flight from Tokyo to Helsinki. VF frequently recurred and shocks were delivered 21 times altogether. The aircraft was diverted to the city of Kuopio. When the local EMS crew encountered the patient 3 h after the onset of the cardiac arrest, the rhythm again converted to VF and three further shocks were delivered. The patient recovered, and 3 wk later he was transported to his home country, fully alert.</AbstractText>There are three large studies reporting placing AEDs on commercial aircraft. No harm for co-passengers or malfunctions were reported. Survival rates have been higher than those obtained by well-performing EMS. According to previous studies, placing AEDs on commercial aircraft is also cost effective. The absence of a suitable diversion destination should not influence the rescuers' decision to attempt CPR on board.</AbstractText> |
6,720 | Effects of exercise testing on natriuretic peptide secretion in patients with atrial fibrillation. | Assessment of endocrine profile in patients with cardiovascular diseases has become increasingly important during the last decade. Plasma brain natriuretic peptide (BNP) levels have been used as a marker of left ventricular dysfunction. However, the role of BNP in patients with atrial fibrillation (AF) and normal left ventricular function has not yet been determined.</AbstractText>To examine changes in the secretion of natriuretic peptides (atrial natriuretic peptide - ANP and BNP) during exercise in patients with persistent or permanent AF.</AbstractText>The study group consisted of 42 patients with permanent AF and 77 patients with persistent AF. There were no significant differences in baseline clinical (except AF duration), echocardiographic and haemodynamic data between the groups. The control group comprised 20 patients. All had normal sinus rhytm without a history of AF and were compatible in age, gender and concomitant diseases with the examined groups. The ANP and BNP samples were obtained at rest and at the peak of the exercise testing. Duration of exercise testing was 10 min.</AbstractText>The multiple regression analysis showed an association between ANP levels and left atrial volume (p = 0.0001), maximal heart rate (p = 0.0036) and NYHA class (p < 0.0001). There was a trend toward a significant relation between AF duration and ANP levels. There was a significant correlation between BNP levels and heart failure class according to NYHA (p < 0.0001). A significant and strong positive correlation of ANP and BNP concentrations at rest was observed in all groups of AF. Significant variation of natriuretic peptide release in response to exercise (ANPex and BNPex) was observed. The highest increase of ANP level and the lowest increase of BNP level were noted in the control group, and no significant differences were found in ANP and BNP secretion between the groups with persistent and permanent AF.</AbstractText>Neurohormonal response to exercise differs between patients with AF and those in sinus rhythm. Exercise testing may be used to assess the ability of cardiac myocytes to increase peptide secretion.</AbstractText> |
6,721 | Successful catheter ablation of focal ventricular fibrillation originating from the right ventricle. | Sudden cardiac death from ventricular fibrillation (VF) typically occurs in patients with structural heart disease, but in 5 to 10 percent VF is "idiopathic," occurring in normal hearts. Recently, there has been the description and growing recognition of patients with VF that has a focal origin, the common sites being in the right ventricular outflow tract (RVOT) and sites in the left ventricle. A focus within the right ventricle outside the RVOT is rare. We present a case of a woman with VF storm that was localized to the inferobasal right ventricle and was successfully treated with radiofrequency ablation. |
6,722 | Atrial tachycardia initiating atrial fibrillation successfully ablated in the non-coronary cusp of the aorta. | A 60-year-old woman was referred for catheter ablation of atrial fibrillation (AF). Atrial flutter and atrial tachycardia (AT) also had been clinically documented. During the electrophysiological study, the clinical AT was induced by burst atrial pacing during isoproterenol infusion and exhibited negative P waves in the inferior leads, positive P waves in leads I, aVL, and aVR, and biphasic P waves in lead V1. The AT repeatedly and spontaneously accelerated to initiate AF by causing fibrillatory conduction in the atria. Successful catheter ablation of the AT was achieved in the non-coronary cusp of the aorta (NCC) where the local atrio-ventricular electrogram amplitude ratio was >1 during both the AT and sinus rhythm. The tailored approach targeting the NCC AT alone without left atrial ablation completely eliminated the AF. In catheter ablation of AF in a patient with a co-existing clinical AT, it may be recommended to examine the clinical AT first. If the clinical AT initiates the AF and local atrial activations in the His bundle region precede the P wave onset during AT, mapping in the NCC should be considered prior to left atrial catheterization. |
6,723 | Post placement positional atrial fibrillation and peripherally inserted central catheters. | Arrhythmias are common in hospitalized patients and during surgery. We present a case of positional atrial arrhythmia related to a peripherally inserted central catheter (PICC). There are other documented case reports of ventricular tachycardia precipitated by body position changes with a PICC. The immediate correction of the arrhythmia with repositioning of the PICC strongly points to the PICC as the cause. This highlights the potential seriousness of cardiac arrhythmias precipitated by PICCs as well as the need for careful catheter placement and perioperative maintenance. Practitioners should consider PICC line tip position as a rare cause of positional atrial arrhythmias. |
6,724 | Life-threatening left main stenosis induced by compression from a dilated pulmonary artery. | On a rare occasion, pulmonary artery dilatation can be complicated by an extrinsic compression of the left main coronary artery (LMCA) whose effects are immediately evident, whereas a delayed presentation is unusual. We report the uncommon case of a delayed acute coronary syndrome caused by the extrinsic compression of the LMCA due to pulmonary artery enlargement and the potential problems related to its management. An 82-year-old woman with a history of severe chronic obstructive pulmonary disease, a previous episode of deep venous thrombosis and a computed tomography-documented pulmonary artery dilatation was referred to the emergency room for worsening dyspnoea and chest pain. Five days after admission to the coronary care unit, the patient developed a cardiogenic shock with consecutive episodes of ventricular fibrillation. Urgent coronary angiography showed severe LMCA stenosis caused by extrinsic compression from the pulmonary artery with no other lesions in the coronary arteries; coronary angioplasty was successfully performed with a direct drug-eluting stent implantation that led to a significant improvement of the haemodynamic conditions in the following days. Planned control angiography performed 10 days later showed the recurrence of the LMCA stenosis together with a forward displacement of the previously implanted drug-eluting stent, which was managed with a further direct implantation of a bare metal stent. The immediate good results of this second procedure were confirmed by follow-up angiography performed 2 months later and by the 6-month follow-up clinical examination. |
6,725 | Effect of biventricular pacing on ventricular repolarization and functional indices in patients with heart failure: lack of association with arrhythmic events. | We prospectively assessed the effects of biventricular (BiV) pacing on electrocardiographic (ECG) and vectorcardiographic (VCG) descriptors of ventricular depolarization and repolarization and their association with appropriate implantable cardioverter defibrillator (ICD) activation.</AbstractText>We studied 70 consecutive heart failure (HF) (37 ischaemic) patients (64 males, age 66.3 years) with a history of syncope or sustained ventricular tachycardia (VT) who underwent implantation of a BiV-ICD. An invasive electrophysiological study (EPS) was performed before the implantation and 12-lead digital ECGs before and 30 days after implantation. Serial echocardiographic studies were performed. Follow-up duration was 1 year. Maximum (P < 0.001) and minimum (P = 0.004) QT intervals were significantly decreased, whereas QT dispersion was not altered (P = 0.086). QRS duration was shortened (P < 0.001), whereas QRS dispersion was significantly decreased (P = 0.034). Spatial T and QRS vector amplitudes decreased (P < 0.001, for both), whereas the spatial QRS-T angle was not affected (P = 0.671). Twenty-seven (38.6%) patients, experienced appropriate ICD therapies during follow-up. None of the ECG or VCG parameters (pre- or post-implant) were able to identify patients with appropriate ICD therapies during follow-up. Only the presence of a previous episode of sustained VT (spontaneous or inducible on EPS) was strongly associated with appropriate ICD therapies (multivariate P = 0.00 014; odds ratio 24.5).</AbstractText>Improvement or no alteration of ECG and VCG descriptors of ventricular depolarization and repolarization was demonstrated after implantation of a BiV-ICD in HF patients. None of these parameters were associated with appropriate ICD therapies, whereas a previous episode of VT or induction of sustained VT on EPS predicted appropriate ICD treatments.</AbstractText> |
6,726 | Exploring QT interval changes as a precursor to the onset of ventricular fibrillation/tachycardia. | In the present study, we have retrospectively analyzed the corrected QT (QTc) interval before spontaneous episodes of sudden cardiac arrest in patients with a wearable cardioverter defibrillator. Corrected QT interval was measured for all normal beats from 32 recordings of baseline rhythm and compared to normal rhythm before a paired spontaneous cardiac arrhythmia. Before arrhythmia, the QTc (505 +/- 73 ms) was not significantly longer than the baseline rhythm (497 +/- 73 ms) (P = .23). Considering ventricular tachycardia (VT) events only (12 patients), event QTc (526 +/- 75 ms) was not significantly longer than baseline QTc (520 +/- 74 ms) (P = .41). Considering fast VT/ventricular fibrillation (VF) events only (20 patients), event QTc (494 +/- 70 ms) was not significantly longer than baseline QTc (483 +/- 71 ms) (P = .26). The influence of QTc as a measure to indicate an impending VT event in a variety of VT/VF patients remains unclear. |
6,727 | Severe rhabdomyolysis and acute renal failure secondary to concomitant use of simvastatin with rapamycin plus tacrolimus in liver transplant patient. | To report a severe interaction between simvastatin and rapamycin resulting in rhabdomyolysis and acute renal failure in a liver transplant patient.</AbstractText>A 56-year-old man with hepatitis C virus cirrhosis (Child B) was diagnosed with hepatocellular carcinoma and underwent liver transplantation in April 2007. He was immunosuppressed with tacrolimus (FK) and mycophenolate mofetil (MMF). Postoperative complications were arterial hypertension and renal insufficiency. In June 2007, liver dysfunction was detected and acute rejection was diagnosed by biopsy. He received three 500-mg boluses of methylprednisolone and FK levels were maintained between 10 and 12 ng/mL. Laboratory values revealed persistent rejection and MMF was stopped with initiation of rapamicin. One month later, hyperlipidemia appeared as a consequence of rapamicin therapy; simvastatin was administered. In August 2007, the patient was readmitted due to severe muscule pain and the inability to ambulate. Laboratory values were: total bilirubin 16 mg/dL, serum creatinine 4.3 mg/dL, and total creatine kinase (CK) 42,124 U/L. With the suspicion of rhabdomyolysis, leading to worsening of his basal renal insufficiency, rapamycin and tacrolimus were stopped. Hemodialysis was initiated owing to renal failure and hyperkalemia. Some hours later, the patient developed ventricular fibrillation and respiratory failure and succumbed.</AbstractText>Calcineurin inhibitors (CNI), corticosteroids, and mammalian target of rapamycin (m-TOR) inhibitors are associated with adverse dyslipidemic effects. To reduce the overall cardiovascular risk in these patients, lipid-lowering drugs, especially 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, have been widely used. CNI and m-TOR inhibitors, as well as most statins, are metabolized by cytochrome P450 (CYP)3A4; thus, pharmacokinetic interactions between these drugs are possible. Previous reports have indicated an increased risk of rhabdomyolysis in the presence of concomitant drugs that inhibit simvastatin metabolism.</AbstractText>Concomitant administration of statin therapy and drugs that inhibit cytochrome P450 (CYP)3A4 increased the risk of rhabdomyolysis in a patient suffering liver and renal dysfunction.</AbstractText> |
6,728 | Doppler-derived preoperative mitral regurgitation volume predicts postoperative left ventricular dysfunction after mitral valve repair. | Unexpected postoperative left ventricular (LV) dysfunction after valve repair for mitral regurgitation (MR) occurs in some patients with normal preoperative LV function. Identification of factors that predispose to such LV dysfunction would enhance our understanding of the indications and outcomes of surgery.</AbstractText>We retrospectively analyzed pre- and postoperative (median fourth day) echocardiograms of 174 patients undergoing valve repair for pure and isolated MR. Preoperative MR volume was quantified by the quantitative Doppler and/or proximal isovelocity surface area method.</AbstractText>There was an incremental predictive value of MR quantification over the current recommendations (global chi(2) from 48.14 to 81.57, P < .001; Hosmer-Lemeshow test, P = .98), for postoperative LV dysfunction, defined as ejection fraction <50%. The independent predictors were MR volume and LV end-systolic dimension (P < .001 and P = .01, respectively). Sixty-nine patients underwent surgery before development of the current surgical criteria, namely, symptoms, atrial fibrillation, preoperative LV dysfunction, or pulmonary hypertension. Of these, MR volume was the only independent significant predictor (P < .001) of unexpected postoperative LV dysfunction that developed in 14 patients (20%). Unexpected LV dysfunction could be predicted with sensitivity of 86% (95% CI 67%-100%) and specificity of 89% (95% CI 81%-97%), using the optimal cutoff of 80 mL for MR volume.</AbstractText>Doppler-derived preoperative MR volume is a powerful predictor of unexpected postoperative LV dysfunction. Prompt mitral valve repair may be beneficial for patients with high likelihood of successful repair and MR volume >/=80 mL.</AbstractText> |
6,729 | The patient with atrial fibrillation. | Atrial fibrillation is a frequently encountered arrhythmia, particularly affecting the elderly. Patients at significant risk for stroke should be considered for anticoagulation with warfarin. Management of atrial fibrillation revolves around either controlling the ventricular rate response or trying to maintain sinus rhythm with either pharmacologic or nonpharmacologic therapies. There are many treatment options to consider, based upon the patient's expectations, symptoms, and comorbid conditions. Therefore, the treatment of atrial fibrillation must be individualized. |
6,730 | Out of hospital cardiac arrest outside home in Sweden, change in characteristics, outcome and availability for public access defibrillation. | A large proportion of patients who suffer from out of hospital cardiac arrest (OHCA) outside home are theoretically candidates for public access defibrillation (PAD). We describe the change in characteristics and outcome among these candidates in a 14 years perspective in Sweden.</AbstractText>All patients who suffered an OHCA in whom cardiopulmonary resuscitation (CPR) was attempted between 1992 and 2005 and who were included in the Swedish Cardiac Arrest Register (SCAR). We included patients in the survey if OHCA took place outside home excluding crew witnessed cases and those taken place in a nursing home.</AbstractText>26% of all OHCAs (10133 patients out of 38710 patients) fulfilled the inclusion criteria. Within this group, the number of patients each year varied between 530 and 896 and the median age decreased from 68 years in 1992 to 64 years in 2005 (p for trend = 0.003). The proportion of patients who received bystander CPR increased from 47% in 1992 to 58% in 2005 (p for trend < 0.0001). The proportion of patients found in ventricular fibrillation (VF) declined from 56% to 50% among witnessed cases (p for trend < 0.0001) and a significant (p < 0.0001) decline was also seen among non witnessed cases.The median time from cardiac arrest to defibrillation among witnessed cases was 12 min in 1992 and 10 min in 2005 (p for trend = 0.029). Survival to one month among all patients increased from 8.1% to 14.0% (p for trend = 0.01). Among patients found in a shockable rhythm survival increased from 15.3% in 1992 to 27.0% in 2005 (p for trend < 0.0001).</AbstractText>In Sweden, there was a change in characteristics and outcome among patients who suffer OHCA outside home. Among these patients, bystander CPR increased, but the occurrence of VF decreased. One-month survival increased moderately overall and highly significantly among patients found in VF, even though the time to defibrillation changed only moderately.</AbstractText> |
6,731 | Impact of induced cardiac arrest on cognitive function after implantation of a cardioverter-defibrillator. | Implantable cardioverter-defibrillators (ICD) were introduced in clinical practice in 1980 and they are considered the standard treatment for individuals at risk for fatal ventricular arrhythmias. To ensure proper working conditions, the energy necessary to interrupt ventricular tachycardia or ventricular fibrillation should be determined during implantation by a test called defibrillation threshold. For this test, it is necessary to induce ventricular fibrillation, which should be identified and treated by the device. The objective of the present study was to determine the frequency of cognitive dysfunction 24 hours after the implantation of a cardioverter-defibrillator.</AbstractText>Thirty consecutive patients with indication of cardioverter-defibrillator (ICD) placement and 30 patients with indication of implantable pacemaker (PM) were enrolled in this study. Patients were evaluated at the following moments: 24 hours before placement of the ICD or PM with a pre-anesthetic evaluation form, Mini Mental State Examination (MMSE), and Confusion Assessment Method (CAM); during implantation of the ICD or PM, the following parameters were determined: number of cardiac arrests and total time of cardiac arrest. Twenty-four hours after placement of the device, the following parameters were evaluated: MMSE and CAM.</AbstractText>Differences in the frequency of altered MMSE and CAM scores between both groups before and after implantation were not detected by the Fisher Exact test. The mean time of cardiac arrest was 7.06 seconds, with a maximal of 15.1 and minimal of 4.7 seconds.</AbstractText>Induction of cardiac arrest during defibrillation threshold testing did not cause cognitive dysfunction 24 hours after implantation of the cardioverter-defibrillator.</AbstractText> |
6,732 | Erythropoietin facilitates the return of spontaneous circulation and survival in victims of out-of-hospital cardiac arrest. | Erythropoietin activates potent protective mechanisms in non-hematopoietic tissues including the myocardium. In a rat model of ventricular fibrillation, erythropoietin preserved myocardial compliance enabling hemodynamically more effective CPR.</AbstractText>To investigate whether intravenous erythropoietin given within 2 min of physician-led CPR improves outcome from out-of-hospital cardiac arrest.</AbstractText>Erythropoietin (90,000 IU of beta-epoetin, n=24) was compared prospectively with 0.9% NaCl (concurrent controls=30) and retrospectively with a preceding group treated with similar protocol (matched controls=48).</AbstractText>Compared with concurrent controls, the erythropoietin group had higher rates of ICU admission (92% vs 50%, p=0.004), return of spontaneous circulation (ROSC) (92% vs 53%, p=0.006), 24-h survival (83% vs 47%, p=0.008), and hospital survival (54% vs 20%, p=0.011). However, after adjusting for pretreatment covariates only ICU admission and ROSC remained statistically significant. Compared with matched controls, the erythropoietin group had higher rates of ICU admission (92% vs 65%, p=0.024) and 24-h survival (83% vs 52%, p=0.014) with statistically insignificant higher ROSC (92% vs 71%, p=0.060) and hospital survival (54% vs 31%, p=0.063). However, after adjusting for pretreatment covariates all four outcomes were statistically significant. End-tidal PCO(2) (an estimate of blood flow during chest compression) was higher in the erythropoietin group.</AbstractText>Erythropoietin given during CPR facilitates ROSC, ICU admission, 24-h survival, and hospital survival. This effect was consistent with myocardial protection leading to hemodynamically more effective CPR (Trial registration: http://isrctn.org. Identifier: ISRCTN67856342).</AbstractText> |
6,733 | Resuscitation after cardiac surgery: results of an international survey. | A survey was conducted on CTSNet, the cardiothoracic network website in order to ascertain an international viewpoint on a range of issues in resuscitation after cardiac surgery.</AbstractText>From 40 questions, 19 were selected by the EACTS clinical guidelines committee. Respondents were anonymous but their location was determined by their Internet protocol (IP) address. The responses were checked for duplication and completion errors and then the results were presented either as percentages or median and range.</AbstractText>From 387 responses, 349 were suitable for inclusion from 53 countries. The median size of unit of respondents performed 560 cases per year. The incidence of cardiac arrest reported was 1.8%, emergency resternotomy after arrest 0.5% and emergency reinstitution of bypass 0.2%. Only 32% of respondents follow current guidelines on resuscitation in their unit and an additional 25% of respondents have never read these guidelines. Respondents indicated that they would perform three attempts at defibrillation for ventricular fibrillation without intervening external cardiac massage and for all arrests perform emergency resternotomy within 5 min if within 24h of the operation. Fifty percent of respondents would give adrenaline immediately, 58% of respondents would be happy for a non-surgeon to perform an emergency resternotomy and 76% would allow a surgeon's assistant and 30% an anaesthesiologist to do this. Only 7% regularly practise for arrests, but 80% thought that specific training in this is important.</AbstractText>This survey supports the EACTS guideline for resuscitation in cardiac arrest after cardiac surgery published in this issue of the journal.</AbstractText> |
6,734 | Implementing cardiac resynchronization therapy in routine clinical practice: preoperative considerations and implantation techniques. | Cardiac resynchronization therapy (CRT) using coronary sinus (CS) leads is an established therapy for congestive heart failure in patients with asynchronous ventricular contractions. CRT improves not only exercise tolerance but also the patient's prognosis. Appropriate patient selection for CRT is essential for a successful therapeutic response. Inclusion criteria are based on symptoms (New York Heart Association classes III and IV), a reduced ejection fraction, and a widened QRS complex. The presence of objective markers of heart failure can be considered a prerequisite for successful CRT. CRT procedures are much longer than regular pacemaker implantations, and thus the risk of infection may be greater. Successful therapy depends on the placement of left ventricular leads, usually via the CS, which is a technically more challenging procedure than regular pacemaker implantations. Complications specific to CRT include ventricular arrhythmia, such as ventricular tachycardia or ventricular fibrillation; total atrioventricular block or sinus arrest without any escape rhythm; and CS dissection. |
6,735 | Mortality and atrial fibrillation: is there a causal relationship? | Almost all studies show that atrial fibrillation (AF) is associated with increased mortality. What is less certain is whether this association is a straightforward cause-and-effect relationship, or if AF is merely a marker of severity of cardiovascular disease(s) or the aging process. AF can lead to the worsening of left ventricular filling, contribute to loss of atrioventricular synchrony, affect cardiac remodeling, and even cause a tachycardia-induced cardiomyopathy. AF could be a marker for underlying atherosclerotic disease that itself determines mortality, or the increased oxygen consumption associated with an increasing ventricular rate may lead to ischemia secondary to increased myocardial consumption and precipitate acute coronary syndromes. Although it is generally accepted that the stasis of atrial blood in AF promotes clot formation, studies have shown increases in specific coagulation factors-all of which have the ability to increase morbidity and/or mortality through their elevations. Another possibility is that AF is not the cause of the hypercoagulable state, but is instead a marker of such a state. |
6,736 | Sevoflurane postconditioning converts persistent ventricular fibrillation into regular rhythm. | Recent studies showed that ischaemic postconditioning converted persistent ventricular fibrillation to sinus rhythm. The influence of anaesthetic postconditioning on ventricular fibrillation has not yet been determined. In the present study, we studied the possible effect of sevoflurane postconditioning on persistent reperfusion-induced ventricular fibrillation in the isolated rat heart model.</AbstractText>Isolated Langendorff-perfused rat hearts (n=80) were subjected to 40 min of global ischaemia and reperfusion. The hearts with persistent ventricular fibrillation (n=16) present after 15 min of reperfusion were then randomly assigned into one of the two groups: controls (n=8), reperfusion was continued for 25 min without any intervention, and sevoflurane postconditioning (n=8), rat hearts in the sevoflurane postconditioning group were exposed to sevoflurane at a concentration of 8.0% for 2 min followed by 23 min of reperfusion. As for the third group, the rest of the hearts were included in the nonpersistently fibrillating hearts group (n=64). Left ventricular pressures, heart rate, coronary flow, electrogram and infarct size were measured as variables of ventricular function and cellular injury, respectively.</AbstractText>Conversion of ventricular fibrillation into regular rhythm was observed in all hearts subjected to sevofluane postconditioning. Regular beating was maintained by all anaesthetic postconditioned hearts during the subsequent reperfusion. None of the hearts in the control group had normal rhythm at the end of the experiment. At the end of reperfusion, the coronary flow was increased in sevoflurane postconditioned hearts compared with the hearts that did not develop persistent ventricular fibrillation.</AbstractText>Sevoflurane postconditioning possesses strong antiarrhythmic effect against persistent reperfusion-induced ventricular fibrillation. Anaesthetic postconditioning may have the potential to be an antiarrhythmic therapy for reperfusion-related arrhythmias.</AbstractText> |
6,737 | Effects of lipid-altering therapies on ventricular arrhythmias and sudden cardiac death. | Sudden cardiac death remains a leading cause of mortality in the United States, with an incidence of 300,000 to 400,000 deaths annually. Despite advances in the management of cardiovascular disease, the only effective treatments proven to reduce the risk of sudden cardiac death are beta-adrenergic blockers and implantable cardioverter-defibrillators. Antiarrhythmic medications are effective at treating symptomatic and asymptomatic ventricular arrhythmias, but several are associated with increased mortality. Although effective at lowering mortality, implantable cardioverter-defibrillators pose an economic burden and some morbidity to patients when associated with frequent shock therapies. Thus, there is renewed interest in developing additional pharmacologic alternatives that could reduce the risk of fatal ventricular arrhythmias. A post hoc analysis of 2 large clinical trials suggested an association between the use of lipid-altering therapy and decreased rates of sudden death. Retrospective review of other clinical trials and experimental data using animal models provide further insight into the potential antiarrhythmic properties of lipid-altering therapy. This review examines the current status of basic science and clinical research that explores the antiarrhythmic properties of lipid-altering therapy, with a focus on 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) and polyunsaturated fatty acids. |
6,738 | Catheter ablation of a posteroseptal accessory pathway in a case with congenital long QT syndrome. | A 23-year-old woman with pre-excitation who was resuscitated from ventricular fibrillation underwent electrophysiologic testing. Successful catheter ablation of a left posteroseptal accessory pathway was achieved. Though the JT and JTc intervals as well as QT and QTc intervals were prolonged before and one day after the ablation, they normalized within about 5 hours after the ablation. This case demonstrated that in a patient with pre-excitation and long QT syndrome (LQTs), the JTc interval was useful for diagnosing LQTs and a longer follow-up of the JTc interval after the ablation was necessary in order not to miss the diagnosis of LQTs. |
6,739 | Short QT syndrome in a pediatric patient. | Short QT syndrome (SQTS) is a recently described genetic syndrome characterized by abnormally brisk ventricular repolarization. Similar to long QT syndrome, SQTS might result in ventricular arrhythmias, syncope, and sudden death. The clinical diagnosis of SQTS is supported by the finding of an abnormally short QT interval on the resting electrocardiogram in combination with a suggestive clinical or family history. To date, few pediatric cases have been reported and the ideal therapy is unknown. We report a teenage boy who suffered a witnessed ventricular fibrillation arrest and was subsequently diagnosed with SQTS. Additional data from nine other pediatric patients diagnosed with SQTS are presented. |
6,740 | [Case of undiagnosed vasospastic angina first noted during anesthesia]. | A 75-year-old man patient was scheduled for total gastrectomy, splenectomy, and cholecyctectomy who had been hypertensive. The patient had no symptoms related to cardiac disease before surgery. Preoperative ECG showed only complete right bundle branch block. After arriving in the operating room, epidural anesthesia was performed at the T8-9 inter space and general anesthesia was induced with propofol without difficulty. Before operation, suddenly PVCs appeared, followed by VT and VF. Immediately the patient was treated with defibrillation, nitroglycerin and nicorandil. The operation was canceled. Vasospastic angina was diagnosed by acetylcholine infusion test postoperatively. Most of patients with vasospastic angina show elevation of ST segment on ECG at first, but our case showed VT and VF without ST elevation on ECG. |
6,741 | Antiplatelet drugs for ischemic stroke prevention. | In primary prevention trials conducted in low-risk subjects, aspirin is associated with a small reduction in ischemic strokes in women. It also reduces the incidence of stroke in patients with nonvalvular atrial fibrillation (NVAF), but warfarin is more effective in patients with high blood pressure, or left ventricular dysfunction, especially those aged >75 years. According to secondary prevention trials in patients after noncardioembolic ischemic stroke or transient ischemic attacks, aspirin at any dose between 50 and 1,300 mg per day reduces the risk of new events, but doses >150 mg per day are associated with a worse gastrointestinal tolerance. Clopidogrel and a combination of aspirin plus extended-release dipyridamole are both slightly more effective than aspirin, but the combination of aspirin and clopidogrel does not reduce the risk of new vascular events and increases life-threatening bleedings. Aspirin cannot be recommended for secondary prevention in NVAF, except in the case of absolute contraindications to warfarin. The available data show that at the acute stage of ischemic stroke, aspirin is safe and slightly more effective than placebo or heparin, even in NVAF, but other antiplatelet agents have not been evaluated. |
6,742 | Cardioembolic stroke: call for a multidisciplinary approach. | Cardioembolic stroke accounts for one third of all ischemic strokes, and atrial fibrillation (AF) is the cardiac source of emboli in 50% of them. However, the absolute risk of stroke associated with AF has enormous variability, and several clinical risk stratification schemes have been proposed. One of the most validated and used in clinical practice is the CHADS2 index, characterized by its simplicity and rapid application. Current recommendations about antithrombotic therapy in AF patients are based on assessment of annual risk of stroke; thus, antiaggregation is indicated in patients with a low risk, and anticoagulation is prescribed when annual risk is greater than 2.5%. Relevant studies comparing rate and rhythm control do not defend achievement and maintenance of sinus rhythm as a routine management of AF patients and demonstrate that rate control is comparable or even better than rhythm control in terms of survival and quality of life. Optimal control of blood pressure is a relevant factor in preventing cardioembolic stroke in AF patients, because hypertension multiplies the risk of stroke by 12. Antihypertensive drugs such as angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers proved to reduce AF recurrences, especially in the context of left ventricular dysfunction and ventricular hypertrophy. |
6,743 | Impacts of ventricular rate regularization pacing at right ventricular apical vs. septal sites on left ventricular function and exercise capacity in patients with permanent atrial fibrillation. | The deleterious effects of right ventricular apex (RVA) pacing may offset the potential benefit of ventricular rate (VR) regularization during atrial fibrillation (AF). Recent studies suggested that right ventricular septal (RVS) pacing may prevent the potential deleterious effects of RVA pacing and enhance the VR regularization (VRR) with ventricular pacing due to closer proximity of the pacing site to the retrograde atrioventricular conduction.</AbstractText>We randomized 24 patients with permanent AF and symptomatic bradycardia to undergo RVA (n = 12) or RVS (n = 12) pacing. A VRR algorithm was programmed for all patients at 6-month after implantation. All patients underwent 6 min hall walk (6MHW) to assess exercise capacity at 6, 12, and 24 months, and radionuclide ventriculography to determine left ventricular ejection fraction (LVEF) at 6 and 24 months. Baseline characteristics were comparable in both groups except pacing QRS duration was significantly shorter during RVS pacing than RVA pacing (132 +/- 4 vs. 151 +/- 6 ms, P = 0.012). In both groups, VRR significantly increased the percentage of ventricular pacing and reduced VR variability (P < 0.05) without increasing mean VR (P > 0.05). At 6 months, 6MHW and LVEF were comparable in patients with RVA and RVS pacing (P > 0.05). At 24 months, patients with RVA pacing had significant decreases in LVEF and 6MHW after VRR pacing (P < 0.05), whereas RVS pacing with VRR preserved LVEF and improved 6MHW (P < 0.05).</AbstractText>In patients with permanent AF, VRR pacing at RVS, but not at RVA, preserves LVEF and provides incremental benefit for exercise capacity.</AbstractText> |
6,744 | Multicenter clinical experience with an atrial lead designed to minimize far-field R-wave sensing. | To evaluate a novel atrial lead designed to reduce far-field sensing.</AbstractText>Sixty-three patients with standard pacing indications were randomized to receive an OptiSense 1699T (St Jude Medical, USA) or conventional pacing lead in the right atrium. Post-implant follow-up was conducted for all patients at 90 days and for a subset at 360 days. Standard electrical parameters were measured. Thresholds of sensing were determined for far-field ventricular signals. The number of inappropriate mode switches was determined from the stored intracardiac electrogram (IEGM). At 90 days, an IEGM Holter recorded 24 h of IEGM. With atrial sensitivity programmed at 0.3 mV, no far-field sensing occurred in the OptiSense group, but it did occur in 20% and 30% of the control group at 90 and 360 days, respectively. Inappropriate mode switching was observed in 4% of the OptiSense group in contrast to 23% of the control group. The IEGM Holter found no far-field sensing in the OptiSense group, but did find 83 023 far-field events from 22% of control patients. The standard electrical parameters of the OptiSense leads were acceptable.</AbstractText>The OptiSense lead reduced ventricular far-field sensing in the atrium while maintaining satisfactory pacing and sensing performance, resulting in less inappropriate mode switch.</AbstractText> |
6,745 | Plasma endothelin-1 level at the onset of ischemic ventricular fibrillation predicts resuscitation outcome. | Endogenous vasopressors, including endothelin-1 (ET-1), have been shown to be elevated in patients following resuscitation from out-of-hospital cardiac arrest and are likely a physiologic response to global ischaemia. The importance of ET-1 in the setting of arrest and resuscitation has not been established. Prior work has demonstrated that ET-1 increases significantly after coronary occlusion. The purpose of this study was to assess changes in ET-1 following induction of ischaemia and VF.</AbstractText>VF was induced in 30 anesthetized and instrumented swine by balloon occlusion of the LAD. Blood was collected from the right atrium at baseline and at 5 min intervals following LAD occlusion until VF occurred. After 7 min of VF, resuscitation was attempted in accordance with guidelines. ET-1 and matrix metalloproteinase-9 (MMP-9), a measure of infarct size, were measured using ELISA.</AbstractText>ET-1 and MMP-9 levels increased significantly from baseline within 20 min of occlusion of the LAD. Animals that could not be resuscitated had a higher ET-1 (p=0.031) at VF onset but similar ischaemia time (time to VF) and MMP-9, reflecting infarct size. An ET-1 level >4 pg/ml had a likelihood ratio of 4 for predicting resuscitation failure.</AbstractText>Elevated levels of ET-1 during acute ischaemia predict resuscitation failure independent of the time to VF. This finding may be due to the known effect of ET-1 on coronary vascular resistance or ventricular compliance, resulting in early ischemic contracture.</AbstractText> |
6,746 | Use of a thrombelastograph platelet mapping assay for diagnosis of clopidogrel resistance: a case report. | A 62-year-old woman presented to the emergency department with sudden collapse, intractable ventricular fibrillation, and an inferior wall myocardial infarction (MI). An emergent cardiac catheterization showed a totally occluded right coronary artery (RCA). A bare-metal stent was placed in the stenosis, resulting in thrombolysis in myocardial infarction (TIMI)-III flow with 0% residual stenosis. Four days after stenting, the patient developed chest pain. A repeat cardiac catheterization showed a totally occluded stent. The patient was subsequently tested using a thrombelastograph (TEG) Platelet Mapping assay to exclude clopidogrel resistance. The assay confirmed the patient to be non-responsive to clopidogrel for the inhibition of platelet ADP receptors. In an attempt to increase ADP inhibition, the ADP antagonist was changed to ticlopidine. Further testing was confounded by the presence of abciximab; however, the patient has remained free of cardiac events. |
6,747 | Dose-response effects of bepridil in patients with persistent atrial fibrillation monitored with transtelephonic electrocardiograms: a multicenter, randomized, placebo-controlled,double-blind study (J-BAF Study). | A multicenter, randomized, placebo-controlled, double-blind trial was conducted with patients with persistent atrial fibrillation (AF) to determine the dose-response effects and safety of bepridil, using every-day transtelephonic monitorings.</AbstractText>A total of 90 patients were randomized to receive placebo, 100 mg/day and 200 mg/day of bepridil treatment for 12 weeks. After the treatment, those patients who converted to sinus rhythm was 3.4% in placebo, 37.5% in those who received 100 mg/day and 69.0% in those who received 200 mg/day, thus demonstrating a linear dose-response relationship for AF conversion. The conversion rate gradually reached a maximal value at approximately 6 weeks after initiation of bepridil. However, the AF recurrence rate was high (91.7% in those receiving 100 mg/day and 75.0% in those receiving 200 mg/day). Adverse events, presumably related to the drug, were also frequent: ventricular tachycardia in 2, QT prolongation in 4 and sinus bradycardia in 2 patients. In those patients treated with 200 mg/day group, 1 patient died suddenly because of ventricular tachycardia.</AbstractText>This study demonstrated the dose response-relationships of bepridil for AF conversion to sinus rhythm. However, the high rate of AF recurrence and substantial drug-related adverse effects, including sudden death, raised caution about using bepridil to treat persistent AF. The balance between benefits and risks of the drug should be individualized.</AbstractText> |
6,748 | QRS prolongation is associated with high defibrillation thresholds during cardioverter-defibrillator implantations in patients with hypertrophic cardiomyopathy.<Pagination><StartPage>1028</StartPage><EndPage>1032</EndPage><MedlinePgn>1028-32</MedlinePgn></Pagination><Abstract><AbstractText Label="BACKGROUND" NlmCategory="BACKGROUND">Although high defibrillation threshold (DFT) is a major and unavoidable clinical problem after implantation of an implantable cardioverter defibrillator (ICD), little is known about the cause and management of a high DFT in patients with hypertrophic cardiomyopathy (HCM). The purpose of this study was to assess the predictors of a high DFT in patients with HCM.</AbstractText><AbstractText Label="METHODS AND RESULTS" NlmCategory="RESULTS">Twenty-three patients with non-dilated HCM who underwent ICD implantation were included. The DFT at the time of the device implantation was measured in all patients. The patients were divided into 2 groups, a high DFT group (DFT >or=15J, n=13) and a low DFT group (DFT <15J, n=10); and their baseline characteristics were compared. The QRS duration was longer in the high than in the low DFT group (128 +/-31 vs 103 +/-12 ms, respectively; P=0.02). QRS duration, left ventricular (LV) end-systolic diameter, and LV ejection fraction were significant predictors of DFT in univariate analysis. However, in multivariate analysis, the only factor significantly associated with DFT was QRS duration (P=0.002).</AbstractText><AbstractText Label="CONCLUSIONS" NlmCategory="CONCLUSIONS">QRS duration is the most consistent predictor of a high DFT in HCM patients undergoing ICD implantation.</AbstractText></Abstract><AuthorList CompleteYN="Y"><Author ValidYN="Y"><LastName>Nagai</LastName><ForeName>Takayuki</ForeName><Initials>T</Initials><AffiliationInfo><Affiliation>Division of Cardiology, Department of Internal Medicine, National Cardiovascular Center, Suita, Japan.</Affiliation></AffiliationInfo></Author><Author ValidYN="Y"><LastName>Kurita</LastName><ForeName>Takashi</ForeName><Initials>T</Initials></Author><Author ValidYN="Y"><LastName>Satomi</LastName><ForeName>Kazuhiro</ForeName><Initials>K</Initials></Author><Author ValidYN="Y"><LastName>Noda</LastName><ForeName>Takashi</ForeName><Initials>T</Initials></Author><Author ValidYN="Y"><LastName>Okamura</LastName><ForeName>Hideo</ForeName><Initials>H</Initials></Author><Author ValidYN="Y"><LastName>Shimizu</LastName><ForeName>Wataru</ForeName><Initials>W</Initials></Author><Author ValidYN="Y"><LastName>Suyama</LastName><ForeName>Kazuhiro</ForeName><Initials>K</Initials></Author><Author ValidYN="Y"><LastName>Aihara</LastName><ForeName>Naohiko</ForeName><Initials>N</Initials></Author><Author ValidYN="Y"><LastName>Kobayashi</LastName><ForeName>Junjiro</ForeName><Initials>J</Initials></Author><Author ValidYN="Y"><LastName>Kamakura</LastName><ForeName>Shiro</ForeName><Initials>S</Initials></Author></AuthorList><Language>eng</Language><PublicationTypeList><PublicationType UI="D016428">Journal Article</PublicationType></PublicationTypeList><ArticleDate DateType="Electronic"><Year>2009</Year><Month>04</Month><Day>10</Day></ArticleDate></Article><MedlineJournalInfo><Country>Japan</Country><MedlineTA>Circ J</MedlineTA><NlmUniqueID>101137683</NlmUniqueID><ISSNLinking>1346-9843</ISSNLinking></MedlineJournalInfo><CitationSubset>IM</CitationSubset><MeshHeadingList><MeshHeading><DescriptorName UI="D000293" MajorTopicYN="N">Adolescent</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D000328" MajorTopicYN="N">Adult</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D000368" MajorTopicYN="N">Aged</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D002312" MajorTopicYN="N">Cardiomyopathy, Hypertrophic</DescriptorName><QualifierName UI="Q000503" MajorTopicYN="Y">physiopathology</QualifierName><QualifierName UI="Q000628" MajorTopicYN="Y">therapy</QualifierName></MeshHeading><MeshHeading><DescriptorName UI="D017147" MajorTopicYN="Y">Defibrillators, Implantable</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D004562" MajorTopicYN="Y">Electrocardiography</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D005260" MajorTopicYN="N">Female</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D006801" MajorTopicYN="N">Humans</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D008297" MajorTopicYN="N">Male</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D008875" MajorTopicYN="N">Middle Aged</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D015999" MajorTopicYN="N">Multivariate Analysis</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D011237" MajorTopicYN="N">Predictive Value of Tests</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D012189" MajorTopicYN="N">Retrospective Studies</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D017180" MajorTopicYN="N">Tachycardia, Ventricular</DescriptorName><QualifierName UI="Q000503" MajorTopicYN="Y">physiopathology</QualifierName></MeshHeading><MeshHeading><DescriptorName UI="D018487" MajorTopicYN="N">Ventricular Dysfunction, Left</DescriptorName><QualifierName UI="Q000503" MajorTopicYN="N">physiopathology</QualifierName></MeshHeading><MeshHeading><DescriptorName UI="D014693" MajorTopicYN="N">Ventricular Fibrillation</DescriptorName><QualifierName UI="Q000503" MajorTopicYN="Y">physiopathology</QualifierName></MeshHeading><MeshHeading><DescriptorName UI="D055815" MajorTopicYN="N">Young Adult</DescriptorName></MeshHeading></MeshHeadingList></MedlineCitation><PubmedData><History><PubMedPubDate PubStatus="entrez"><Year>2009</Year><Month>4</Month><Day>11</Day><Hour>9</Hour><Minute>0</Minute></PubMedPubDate><PubMedPubDate PubStatus="pubmed"><Year>2009</Year><Month>4</Month><Day>11</Day><Hour>9</Hour><Minute>0</Minute></PubMedPubDate><PubMedPubDate PubStatus="medline"><Year>2009</Year><Month>9</Month><Day>18</Day><Hour>6</Hour><Minute>0</Minute></PubMedPubDate></History><PublicationStatus>ppublish</PublicationStatus><ArticleIdList><ArticleId IdType="pubmed">19359812</ArticleId><ArticleId IdType="doi">10.1253/circj.cj-08-0744</ArticleId><ArticleId IdType="pii">JST.JSTAGE/circj/CJ-08-0744</ArticleId></ArticleIdList></PubmedData></PubmedArticle><PubmedArticle><MedlineCitation Status="MEDLINE" Owner="NLM"><PMID Version="1">19359720</PMID><DateCompleted><Year>2009</Year><Month>08</Month><Day>18</Day></DateCompleted><DateRevised><Year>2009</Year><Month>04</Month><Day>10</Day></DateRevised><Article PubModel="Print"><Journal><ISSN IssnType="Print">1512-0112</ISSN><JournalIssue CitedMedium="Internet"><Issue>168</Issue><PubDate><Year>2009</Year><Month>Mar</Month></PubDate></JournalIssue><Title>Georgian medical news</Title><ISOAbbreviation>Georgian Med News</ISOAbbreviation></Journal>[Ventricular arrhythmias and sudden cardiac death]. | Sudden cardiac death (SCD) - this natural death caused by cardiac reasons and which is characterized by sudden loss of consciousness within first hour after revealing of sharp clinical symptoms. A primary factor of SCD is not traumatic. It occurs suddenly and unexpectedly. The high risk of development of sudden cardiac death is basically associated with ventricular arrhythmias. Electrophysiological anomalies in cells lead to development of ventricular ectopic activity or ventricular tachycardia which comes to the end with fibrillation. The ultimate goal of antiarrhythmic drug therapy is to restore normal rhythm and conduction Treatment of ventricular arrhythmia provides application of antiarrhythmic medicines, beta-adrenoblokators, amiodarone, lidocaine, sotalole, implantation cardioverters - defibrillators (ID), catheter ablation, surgical manipulations. ID therapy is recommended for primary prevention developments SCD in patients with ventricular fibrillation against a background of the acute miocardial infarction. |
6,749 | Effect of cardiac resynchronization therapy on the incidence of electrical storm. | Hemodynamic improvement from biventricular pacing is well documented; however, its electrophysiologic effects have not been systematically studied. In this study, incidence and risk factors for electrical storm (ES) were investigated in 729 ICD and biventricular defibrillator (CRT-D) heart failure patients.</AbstractText>168 consecutive CRT-D and 561 ICD patients were retrospectively analyzed for the occurrence of VT/VF and predisposing factors. Electrical storm was defined as ventricular tachycardia or fibrillation ≥3 times during 24 h. Mean follow-up was 41 months.</AbstractText>In 168 CRT-D patients only one patient experienced electrical storm compared to 39 patients out of 561 ICD patients (0.6% vs. 7%, p<0.01). 33% of the patients with electrical storm died within one year. In the CRT-D group 81 patients (48%) developed VT or VF and received at least one appropriate therapy, compared to 281 patients (50%) in the ICD group. Mean ejection fraction was 21.7% in the CRT-D group and 34.7% (p<0.01) in the ICD group. Stratifying the patients according to primary or secondary prevention and ejection fraction demonstrated that VT/VF clusters were significantly associated with ICD indication for secondary prevention, previous myocardial infarction and LVEF<30%.</AbstractText>The development of electrical storm is accompanied with a highly increased mortality risk even if an ICD/CRT-D is implanted. In CRT-D patients electrical storm is much less common than in ICD patients. Secondary prevention and ejection fraction<30% are predictors of electrical storm. Beside hemodynamic improvements cardiac resynchronization therapy may reduce the arrhythmia burden in heart failure patients.</AbstractText>Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
6,750 | Atrial flutter, ventricular tachycardia and changing axis deviation associated with scleroderma. | Rhythm disturbances have been described in immunological and connective diseases. Scleroderma is a fibrotic condition characterized by immunological abnormalities, vascular injury and increased accumulation of extracellular matrix proteins. The heart is one of the major organs involved in scleroderma, the involvement of which can be manifested by myocardial disease, conduction system abnormalities, arrhythmias, or pericardial disease. Additionally, scleroderma renal crisis and pulmonary hypertension lead to significant cardiac dysfunction secondary to damage in the kidney and lung. Changing axis deviation has been reported also during atrial fibrillation or atrial flutter. Changing axis deviation has been also reported during acute myocardial infarction associated with atrial fibrillation too or at the end of atrial fibrillation during acute myocardial infarction. We present a case of atrial flutter, ventricular tachycardia and changing axis deviation in a 61-year-old Italian woman with scleroderma. This case focuses attention on changing axis deviation and on the presentation of arrhythmias in scleroderma. The underlying arrhythmogenic mechanisms are probably multiple and intriguing, even though the myocardial fibrosis and immunological autoantibody-mediated mechanisms seem to play a pivotal role. |
6,751 | Effects of verapamil on anterior ST segment and ventricular fibrillation cycle length in patients with Brugada syndrome. | This study examined the effects of verapamil (5-10 mg intravenous) on the cardiac electrical activity of 10 Brugada syndrome (BS) patients having vasospastic angina, atrial fibrillation, and/or hypertension.</AbstractText>Verapamil showed no significant change in the ST-segment elevation. Likewise, there was no significant change in the lengths of QRS complex, HV and corrected QT intervals, or effective refractory period at the right ventricle. The conduction time between right ventricular apex and outflow tract, measured at 400-millisecond pacing, was mildly prolonged by verapamil. At baseline, induced ventricular fibrillation (VF) was terminated by a 200-J shock in all patients. After verapamil, VF was reinduced in 7, was noninducible in 2, and self-terminated in 1 patient. Mean F-F interval was shorter after than before verapamil, and a 360-J shock was required in 2 of the 7 patients.</AbstractText>In some BS patients, calcium channel blockade may modify the electrical characteristics of VF.</AbstractText> |
6,752 | Outcomes in mitral regurgitation due to flail leaflets a multicenter European study. | The purpose of this study was to assess incidence and predictors of events associated with nonsurgical and surgical management of severe mitral regurgitation (MR) in European institutions.</AbstractText>The management of patients with MR remains disputed, warranting multicenter studies to define clinical outcome in routine clinical practice.</AbstractText>The MIDA (Mitral Regurgitation International DAtabase) is a registry created for multicenter study of MR with echocardiographically diagnosed flail leaflet as a model of pure, organic MR. Our cases were collected from 4 European centers. We enrolled 394 patients (age 64 +/- 11 years; 67% men; 64% in New York Heart Association functional class I to II; left ventricular ejection fraction 67 +/- 10%).</AbstractText>During a median follow-up of 3.9 years, linearized event rates/year under nonsurgical management were 5.4% for atrial fibrillation (AF), 8.0% for heart failure (HF), and 2.6% for death. Mitral valve (MV) surgery was performed in 315 (80%) patients (repair in 250 of 315, 80%). Perioperative mortality, defined as death within 30 days from the operation, was 0.7% (n = 2). Surgery during follow-up was independently associated with reduced risk of death (adjusted hazard ratio [HR] 0.42, 95% confidence interval [CI] 0.21 to 0.84; p = 0.014). Benefit was largely driven by MV repair (adjusted HR vs. replacement 0.37, 95% CI 0.18 to 0.76; p = 0.007). In 102 patients strictly asymptomatic and with normal ventricular function, 5-year combined incidence of AF, HF, or cardiovascular death (CVD) was 42 +/- 8%. In these patients, surgery also reduced rates of CVD/HF (HR 0.26, 95% CI 0.08 to 0.89; p = 0.032).</AbstractText>In this multicenter study, nonsurgical management of severe MR was associated with notable rates of adverse events. Surgery especially MV repair performed during follow-up was beneficial in reducing rates of cardiac events. These findings support surgical consideration in patients with MR due to flail leaflets for whom MV repair is feasible.</AbstractText> |
6,753 | Management of primary aldosteronism: its complications and their outcomes after treatment. | Primary aldosteronism is the most common cause of secondary hypertension, accounting for about 10% of all forms of high blood pressure. Life-time pharmacological therapy is the treatment of choice for primary aldosteronism due to idiopathic adrenal hyperplasia (IHA), while adrenalectomy is effective in curing most patients with an aldosterone producing adenoma (APA). Far from being a benign form of hypertension, primary aldosteronism is characterized by the development of cardiovascular renal and metabolic complications, including left ventricular hypertrophy, myocardial infarction, atrial fibrillation and stroke, microalbuminuria, renal cysts as well as metabolic syndrome, glucose impairment and diabetes mellitus. We review recent clinical experience with the above mentioned complications and long-term outcomes of blood pressure normalization and cardiac, renal and gluco-metabolic complications in patients with primary aldosteronism, after medical treatment with mineralocorticoid receptor antagonists and surgical treatment. We conclude that removal of adrenal adenoma results in normalization of the renin-angiotensin-aldosterone system (RAAS) and of kalaemia and improvement of blood pressure levels in all patients. Complete resolution of hypertension is achieved in nearly half of treated patients. Moreover, unilateral adrenalectomy is the best treatment to have the regression of cardiovascular, renal and metabolic complications in patients with APA. On the other hand, targeted medical treatment with aldosterone antagonists improves blood pressure control and appears able to prevent the progression of cardiac and metabolic complications in patients with IHA. |
6,754 | Selective beta blockade improves the outcome of cardiopulmonary resuscitation in a swine model of cardiac arrest. | Epinephrine has been the mainstay drug of choice for cardiac resuscitation for more than 30 years. Its vasopressor effects favoring initial resuscitation point to its beta-adrenergic action. However, its beta-adrenergic actions may have detrimental effects. The aim of the present experimental study was to evaluate the efficiency of coadministration of Esmolol, an ultra-short-acting beta-blocker, and of epinephrine in a swine model of cardiac arrest.</AbstractText>Fourteen pigs (19 +/- 2 Kg) were anesthetized and instrumented. Ventricular Fibrillation (VF) was produced electrically. After induction of VF, the animals were left untreated for 5 minutes. Animals were randomized into two groups, control and study group. Six animals were used in the control group, and 8 in the study group. The control group received 10 ml of normal saline via a peripheral vein, while the study group received 0.4 mg/kg Esmolol in 10 ml dilution. Epinephrine was administered to all animals after the first unsuccessful defibrillation set, and all animals received standardized Advanced Life Support.</AbstractText>Seven animals (87.5%) restored cardiac rhythm compatible with a pulse in the Esmolol group, compared to 2 animals (33.3%) in the control group (p = 0.018). The average time until restoration of circulation was 16 +/- 3.2 minutes in our control group and 12.8 +/- 1.4 minutes in Esmolol group (p = 0.059). Coronary perfusion pressure (CPP) was significantly higher in the Esmolol group.</AbstractText>Esmolol improves significantly the outcome of cardiopulmonary resuscitation and the average time of restoration of circulation, while in the proposed dosage does not alter the CPP at the beginning of CPR. However, it augments CPP from the sixth minute of CPR and afterwards.</AbstractText> |
6,755 | hERG1 channel activators: a new anti-arrhythmic principle. | The cardiac action potential is the result of an orchestrated function of a number of different ion channels. Action potential repolarisation in humans relies on three potassium current components named I(Kr), I(Ks) and I(K1) with party overlapping functions. The ion channel alpha-subunits conducting these currents are hERG1 (Kv11.1), KCNQ1 (Kv7.1) and Kir2.1. Loss-of-function in any of these currents can result in long QT syndrome. Long QT is a pro-arrhythmic disease with increased risk of developing lethal ventricular arrhythmias such as Torsade de Pointes and ventricular fibrillation. In addition to congenital long QT, acquired long QT can also constitute a safety risk. Especially unintended inhibition of the hERG1 channel constitutes a major concern in the development of new drugs. Based on this knowledge is has been speculated whether activation of the hERG1 channel could be anti-arrhythmic and thereby constitute a new principle in treatment of cardiac arrhythmogenic disorders. The first hERG1 channel agonist was reported in 2005 and a limited number of such compounds are now available. In the present text we review results obtained by hERG1 channel activation in a number of cardiac relevant settings from in vitro to in vivo. It is demonstrated how the principle of hERG1 channel activation under certain circumstances can constitute a new anti-arrhythmogenic principle. Finally, important conceptual differences between the short QT syndrome and the hERG1 channel activation, are evaluated. |
6,756 | Susceptibility genes & modifiers for cardiac arrhythmias. | Cardiac arrhythmias in the absence of structural heart diseases can be subdivided in those cases which are acquired and those which are linked to genetic defects on cardiac ion channels and regulatory subunits. Although acquired arrhythmias do not contain any obviously genetic component the observation of frequently occurring single nucleotide polymorphism (SNPs) identified in cardiac ion channel genes lead to the question if these natural variants can influence the development of acquired forms of cardiac arrhythmias and thus serve as genetic susceptibility markers. This review summarizes the results of genetic association and linkage studies in drug induced long-QT syndrome and atrial and ventricular fibrillation and discusses advantages and future directions of this topic in cardiac research. |
6,757 | A single-cell model of phase-driven control of ventricular fibrillation frequency. | The mechanisms controlling the rotation frequency of functional reentry in ventricular fibrillation (VF) are poorly understood. It has been previously shown that Ba2+ at concentrations up to 50 mumol/L slows the rotation frequency in the intact guinea pig (GP) heart, suggesting a role of the inward rectifier current (I(K1)) in the mechanism governing the VF response to Ba2+. Given that other biological (e.g., sinoatrial node) and artificial systems display phase-locking behavior, we hypothesized that the mechanism for controlling the rotation frequency of a rotor by I(K1) blockade is phase-driven, i.e., the phase shift between transmembrane current and voltage remains constant at varying levels of I(K1) blockade. We measured whole-cell admittance in isolated GP myocytes and in transfected human embryonic kidney (HEK) cells stably expressing Kir 2.1 and 2.3 channels. The admittance phase, i.e., the phase difference between current and voltage, was plotted versus the frequency in control conditions and at 10 or 50 micromol/L Ba2+ (in GP heart cells) or 1 mM Ba2+ (in HEK cells). The horizontal distance between plots was called the "frequency shift in a single cell" and analyzed. The frequency shift in a single cell was -14.14 +/- 5.71 Hz (n = 14) at 10 microM Ba2+ and -18.51 +/- 4.00 Hz (n = 10) at 50 microM Ba2+, p < 0.05. The values perfectly matched the Ba2+-induced reduction of VF frequency observed previously in GP heart. A similar relationship was found in the computer simulations. The phase of Ba2+-sensitive admittance in GP cells was -2.65 +/- 0.32 rad at 10 Hz and -2.79 +/- 0.26 rad at 30 Hz. In HEK cells, the phase of Ba2+-sensitive admittance was 3.09 +/- 0.03 rad at 10 Hz and 3.00 +/- 0.17 rad at 30 Hz. We have developed a biological single-cell model of rotation-frequency control. The results show that although rotation frequency changes as a result of I(K1) blockade, the phase difference between transmembrane current and transmembrane voltage remains constant, enabling us to quantitatively predict the change of VF frequency resulting from I(K1) blockade, based on single-cell measurement. |
6,758 | Electrical storm in Brugada syndrome successfully treated with orciprenaline; effect of low-dose quinidine on the electrocardiogram. | We report a case of an electrical storm occurring in a patient implanted with a cardioverter defibrillator for symptomatic Brugada syndrome. Recurrent ventricular fibrillation was initiated by short-coupled premature ventricular beats of right ventricular origin, associated with a fixed Brugada type 2 electrocardiographic pattern. Low-dose orciprenaline application as an intravenous bolus followed by an infusion inhibited the recurrence of ventricular fibrillation and normalized the electrocardiographic pattern. Low-dose oral quinidine had only a moderate effect on the ST-elevation. |
6,759 | Sudden cardiac arrest due to puerperal transient left ventricular apical ballooning syndrome. | A 37 year old woman with chest pain was admitted to the emergency room 40 days after normal delivery with ventricular fibrillation due to Takotsubo cardiomyopathy. |
6,760 | SCN5A mutation associated with acute myocardial infarction. | Ventricular tachycardia and fibrillation (VT/VF) complicating Brugada syndrome, a genetic disorder linked to SCN5A mutations, and VF complicating acute myocardial infarction (AMI) have both been linked to phase 2 reentry. Because of these mechanistic similarities in arrhythmogenesis, we examined the contribution of SCN5A mutations to VT/VF complicating AMI. Nineteen consecutive patients developing VF during AMI were enrolled. Wild-type (WT) and mutant SCN5A genes were co-expressed with SCN1B in TSA201 cells and studied using whole-cell patch-clamp techniques. One missense mutation (G400A) in SCN5A was detected in a conserved region among the cohort of 19 patients. A H558R polymorphism was detected on the same allele. Unlike the other 18 patients who each developed 1-2 VF episodes during acute MI, the mutation carrier developed six episodes of VT/VF within the first 12 hours. All VT/VF episodes were associated with ST segment changes and were initiated by short-coupled extrasystoles. We describe the first sodium channel mutation to be associated with the development of an arrhythmic storm during acute ischemia. These findings suggest that a loss of function in SCN5A may predispose to ischemia induced arrhythmic storm. These results could be very useful for forensic implications regarding genetic screening in relatives. |
6,761 | Interatrial conduction time and left atrial function in patients with left ventricular systolic dysfunction: effects of cardiac resynchronization therapy. | Prolonged interatrial conduction time (IACT) can be associated with abnormal left atrial (LA) function but has not been characterized in patients with left ventricular (LV) systolic dysfunction (LVSD) and QRS intervals >130 ms.</AbstractText>Two-dimensional Doppler echocardiography and Doppler tissue imaging (DTI) were performed in 41 patients with LVSD (mean LV ejection fraction, 26 +/- 5%) and 41 similarly aged normal controls. Two-dimensional measurements included LV volume and ejection fraction and LA volume for the determination of LA emptying fraction and LA ejection fraction. IACT was defined as the time from the onset of the P wave to the onset of the DTI-derived late diastolic (A') velocity at the lateral mitral annulus. Two-dimensional Doppler measurements were reassessed in patients with LVSD 4 +/- 2 months after cardiac resynchronization therapy (CRT).</AbstractText>IACT was longer in patients with compared to controls (105 +/- 25 vs 74 +/- 12 ms, P < .001); none of the controls had an IACT > 100 ms. In patients with LVSD, IACT was correlated modestly with measurements of LA volume (r = .41-.48, all P values < .009) but not with measurements of LA function. Patients with LVSD with IACTs > 100 ms (n = 20) prior to CRT had larger LA volumes and lower indices of LA function after CRT compared to those with IACTs < or = 100 ms. Significant reductions in LV end-systolic volumes and increases in LV ejection fractions occurred in both groups after CRT.</AbstractText>DTI-derived IACT can be prolonged in patients with severe LVSD and wide QRS intervals. An IACT > 100 ms can affect LA remodeling and function at early follow-up after CRT but does not influence the response in LV end-systolic volume or ejection fraction.</AbstractText> |
6,762 | Valsalva maneuver to predict dynamic intraventricular obstruction during dobutamine stress echocardiography in patients with hypertension. | We were to evaluate the effect of Valsalva maneuver with comparison to preload reduction by nitroglycerin (NTG) to predict intraventricular obstruction (IVO) during dobutamine stress echocardiography (DSE) in patients with hypertension.</AbstractText>A total of 38 hypertensive patients (mean age 66.0±9.9 years; 32% male) were prospectively enrolled. The patients with positive exercise electrocardiography, transmural infarction, significant valvular heart disease, atrial fibrillation, beta-blocker therapy, and induced ischemia during DSE were excluded. The development of an IVO during DSE was defined as a late-peaking intraventricular pressure gradient (IVPG) >30 mmHg.</AbstractText>The patients were divided into 2 groups, without IVO (n=11, non-IVO) and with IVO (n=27). IVO group had smaller left ventricular (LV) cavity and LV end-diastolic volume, and more increased interventricular septum thickness and higher basal septal thickness than non-IVO group. At rest, after Valsalva maneuver, during peak dose of dobutamine, and after NTG, IVPG was higher in IVO-group. To predict IVO during DSE, IVPG ≥5 mmHg after Valsalva maneuver had a sensitivity of 70.4% and specificity of 90.9%. and IVPG ≥4.5 mmHg after NTG had a sensitivity of 33.3% and specificity of 90.9%.</AbstractText>Simple and safe Valsalva maneuver plays an effective role to predict dynamic IVO in patients with hypertension who might be good candidate for beta-blocker therapy and is even more sensitive than preload reduction by NTG.</AbstractText>Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
6,763 | Optimization of feedback pacing for defibrillation. | A mathematical model of multisite feedback pacing for defibrillation is optimized for electrode spacing and stimulus period. For four electrodes, the defibrillation success rate is highest at 88% when the electrodes are spaced as far apart as possible. For a single electrode, the optimum success rate was 26%. |
6,764 | CPR artifact removal in ventricular fibrillation ECG signals using Gabor multipliers. | We present an algorithm for discarding cardiopulmonary resuscitation (CPR) components from ventricular fibrillation ECG (VF ECG) signals and establish a method for comparing CPR attenuation on a common dataset. Removing motion artifacts in ECG allows for uninterrupted rhythm analysis and reduces "hands-off" time during resuscitation.</AbstractText>The current approach assumes a multichannel setting where the information of the corrupted ECG is combined with an additional pressure signal in order to estimate the motion artifacts. The underlying algorithm relies on a localized time-frequency transformation, the Gabor transform, that reveals the perturbation components, which, in turn, can be attenuated. The performance of the method is evaluated on a small set of test signals in the form of error analysis and compared to two well-established CPR removal algorithms that use an adaptive filtering system and a state-space model, respectively.</AbstractText>We primarily point out the potential of the algorithm for successful artifact removal; however, on account of the limited set of human VF and animal asystole CPR signals, we refrain from a statistical analysis of the efficiency of CPR attenuation. The results encourage further investigations in both the theoretical and the clinical setup.</AbstractText> |
6,765 | Intelligent analysis in predicting outcome of out-of-hospital cardiac arrest. | The prognosis among patients who suffer out-of-hospital cardiac arrest is poor. Higher survival rates have been observed only in patients with ventricular fibrillation who were fortunate enough to have basic and advanced life support initiated early after cardiac arrest. The ability to predict outcomes of cardiac arrest would be useful for resuscitation chains. Levels of EtCO(2)in expired air from lungs during cardiopulmonary resuscitation may serve as a non-invasive predictor of successful resuscitation and survival from cardiac arrest. Six different supervised learning classification techniques were used and evaluated. It has been shown that machine learning methods can provide an efficient way to detect important prognostic factors upon which further emergency unit actions are based. |
6,766 | Left ventricular hypertrabeculation/noncompaction associated with coronary heart disease and myopathy. | The association of left ventricular hypertrabeculation (LVHT), also known as noncompaction, coronary heart disease, and metabolic myopathy, as presented in the following report, is rare.</AbstractText>In a 77-yo male with a history of arterial hypertension, coronary heart disease, dilative cardiomyopathy, mitral and tricuspid insufficiency, AV-block III, implantation of a pacemaker, atrial fibrillation, and heart failure, LVHT was detected on transthoracic echocardiography during hospitalization for worsening heart failure. Clinical neurologic investigation, revealing bilateral ptosis, madarosis, absent eyelashes, bilateral hypacusis, sore neck muscles, generally absent deep tendon reflexes, weakness for foot extension, and ataxic stance, and recurrently elevated creatine-kinase with normal troponine, suggested a metabolic myopathy. Autopsy after death from intractable heart failure. 17 months later confirmed severe coronary heart disease and LVHT in the apex.</AbstractText>LVHT may be associated with coronary heart disease and myopathy and may be exclusively located in the left ventricular apex.</AbstractText>Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
6,767 | The mechanisms of atrial fibrillation in hyperthyroidism. | Atrial fibrillation (AF) is a complex condition with several possible contributing factors. The rapid and irregular heartbeat produced by AF increases the risk of blood clot formation inside the heart. These clots may eventually become dislodged, causing embolism, stroke and other disorders. AF occurs in up to 15% of patients with hyperthyroidism compared to 4% of people in the general population and is more common in men and in patients with triiodothyronine (T3) toxicosis. The incidence of AF increases with advancing age. Also, subclinical hyperthyroidism is a risk factor associated with a 3-fold increase in development of AF. Thyrotoxicosis exerts marked influences on electrical impulse generation (chronotropic effect) and conduction (dromotropic effect). Several potential mechanisms could be invoked for the effect of thyroid hormones on AF risk, including elevation of left atrial pressure secondary to increased left ventricular mass and impaired ventricular relaxation, ischemia resulting from increased resting heart rate, and increased atrial eopic activity. Reentry has been postulated as one of the main mechanisms leading to AF. AF is more likely if effective refractory periods are short and conduction is slow. Hyperthyroidism is associated with shortening of action potential duration which may also contribute to AF. |
6,768 | Mode of frequency distribution of external work efficiency of arrhythmic beats during atrial fibrillation remains normal in canine heart. | The external work (EW) efficiency of individual arrhythmic beats of the left ventricle (LV) cannot directly be obtained since LV O(2) consumption (VO(2)) of each beat cannot directly be measured under beat-to-beat varying contractile and loading conditions. We, however, have recently reported that VO(2) of each arrhythmic beat can reasonably be estimated by VO(2) = aPVA + bE(max) + c even under varying PVA and E(max). Here, PVA is the LV pressure-volume (P-V) area as a measure of the LV total mechanical energy, E(max) is the LV end-systolic elastance as an index of the LV contractility, a is a constant O(2) cost of PVA, b is a constant O(2) cost of E(max), and c is the basal metabolic VO(2) of the beat, all on a per-beat basis. Using the above formula in this study, we calculated VO(2) of the individual arrhythmic beats from their measured PVA and E(max) during electrically induced atrial fibrillation (AF) in normal canine hearts. We then calculated their LV EW efficiency by dividing their measured EW with the estimated VO(2). We found that the thus calculated EW efficiency of the arrhythmic beats had a rightward skewed distribution with a mode of 15% and a maximum of 18% around a mean of 13% on average in six hearts. This mode remained comparable to the efficiency (15%) at regular tachycardia though 22% lower than mean arrhythmic tachycardia. |
6,769 | Predictors of atrial fibrillation recurrence in patients with long-lasting atrial fibrillation. | Limited data are available on the predictors of atrial fibrillation (AF) recurrence in patients with chronic AF.</AbstractText>To evaluate potential clinical, echocardiographic and electrophysiological predictors of AF recurrence, after internal cardioversion for long-lasting AF.</AbstractText>A total of 99 consecutive patients (63 men and 36 women, mean age 63.33+/-9.27 years) with long-standing AF (52.42+/-72.02 months) underwent internal cardioversion with a catheter that consisted of two defibrillating coils. Shocks were delivered according to a step-up protocol. Clinical follow-up and electrocardiographic recordings were performed on a monthly basis for a 12-month period or whenever patients experienced symptoms suggestive of recurrent AF.</AbstractText>Ninety-three patients (93.94%) underwent a successful uncomplicated cardioversion, with a mean atrial defibrillation threshold of 10.69+/-6.76 J. Immediate reinitiation of AF was observed in 15 patients (15.78%) of whom a repeated cardioversion restored sinus rhythm in 13 cases. Early recurrence of AF (within one week) was observed in 12 of 93 patients (12.90%). At the end of the 12-month follow-up period, during which seven patients were lost, 42 of the 86 remaining patients (48.84%) were still in sinus rhythm. Multivariate regression analysis showed that left atrial diameter (OR 1.126, 95% CI 1.015 to 1.249; P=0.025) and mitral A wave velocity (OR 0.972, 95% CI 0.945 to 0.999; P=0.044) were significant and independent predictors of AF recurrence, whereas age, left ventricular ejection fraction and AF cycle length were not predictive of arrhythmia recurrence.</AbstractText>The present study showed that the left atrial diameter and mitral A wave velocity are the only variables associated with AF recurrence after successful cardioversion.</AbstractText> |
6,770 | Acetylcholine-regulated K+ current remodelling in the atrium after myocardial infarction and valsartan administration. | Atrial fibrillation (AF) is a common complication of myocardial infarction (MI). Angiotensin II receptor antagonists prevent the promotion and propagation of AF. However, the activation of the acetylcholine-regulated K(+) current (I(K,ACh)) in the atrium after MI and the effect of valsartan on I(K,ACh) are less understood.</AbstractText>Twenty-four adult rabbits were randomly divided into three groups: sham-operated, MI and MI plus valsartan administration (MI+valsartan). The sham-operated group received a median sternotomy without left ventricular coronary artery ligation. Both the MI group and the MI+valsartan group received a median sternotomy followed by ligation of the midpoint of the left ventricular coronary artery. The MI+valsartan group was administered oral valsartan for 12 weeks. After 12 weeks, the initiation of AF was measured by vagal stimulation followed by quick excision of the heart. I(K,ACh) in the left atrial myocardium was measured by the patch clamp technique.</AbstractText>AF was induced in four animals in the MI group, two in the sham-operated and two in the MI+valsartan groups, with the total AF duration expectedly longer in the MI group than in the sham-operated and MI+valsartan groups (38 s versus 9 s and 9 s, respectively). Furthermore, the mean (+/- SEM) density of I(K,ACh) increased significantly more in the left atrial myocardia of the MI group than in the sham-operated and the MI+valsartan groups (-13+/-0.42 pA/pF versus -9+/-0.38 pA/pF and -10+/-0.37 pA/pF, respectively at -100 mV; and 4.1+/-0.28 pA/pF versus 3.1+/-0.27 pA/pF and 3.3+/-0.27 pA/pF, respectively at 20 mV; P<0.05). However, there was no statistically significant difference in I(K,ACh) between the sham-operated group and the MI+valsartan group.</AbstractText>AF is associated with increased I(K,ACh) after MI. Inhibition of increased IK,ACh may be the mechanism by which valsartan prevents AF following MI.</AbstractText> |
6,771 | Predictors of atrial tachyarrhythmias in subjects with type 1 ECG pattern of Brugada syndrome. | Previous studies have demonstrated a high incidence of atrial tachyarrhythmias (ATs) in patients with Brugada syndrome (BS). The present study aimed to investigate whether various 12-lead electrocardiogram (ECG) and electrophysiological parameters may help to differentiate subjects with a high probability to develop ATs.</AbstractText>The clinical records of 38 individuals (31 males, age 44.4 +/- 13.9) with spontaneous (n = 15) or ajmaline-induced (n = 23) type 1 ECG pattern of BS were analyzed. During a mean follow-up period of 4.6 +/- 2.2 years, nine subjects suffered ATs (24%). Six subjects displayed paroxysmal atrial fibrillation and three typical atrial flutter. Among the studied 12-lead ECG parameters, subjects with ATs exhibited increased values of P-wave duration in lead II, P-wave dispersion, PR interval in leads II, QRS duration in leads II and V(2), Tpeak-end interval in lead II, and Tpeak-end dispersion of the 12 leads in relation to those without ATs (P < 0.05). Among the assessed electrophysiological parameters, atrial-His (AH) and His-ventricular (HV) intervals were significantly prolonged in subjects with ATs (P < 0.05). Multiple Cox proportional hazards analysis revealed that P-wave duration in lead II, P-wave dispersion, Tpeak-end in lead II, Tpeak-end dispersion of the 12 leads, as well as AH and HV intervals are independent predictors of ATs in subjects with BS (P < 0.05). Cut-off point analysis showed that an HV interval>or=56 ms displayed the highest predictive ability (P < 0.01).</AbstractText>Our findings demonstrate that simple 12-lead ECG and electrophysiological parameters may easily be applied to identify high-risk subjects with BS ECG phenotype to develop ATs.</AbstractText> |
6,772 | Use of implantable cardioverter-defibrillator in inherited arrhythmogenic diseases: data from Italian ICD Registry for the years 2001-6. | Previous studies have demonstrated the lifesaving role of an implantable cardioverter-defibrillator (ICD) in high-risk patients with genetic arrhythmogenic diseases.</AbstractText>To evaluate the clinical data of patients with hypertrophic cardiomyopathy (HCM), arrhythmogenic right ventricular cardiomyopathy (ARVD/C), idiopathic ventricular arrhythmia (IDIO-VA) including Brugada syndrome, short QT syndrome, and long QT syndrome (LQT) enrolled in the Italian ICD Registry in the years 2001-6.</AbstractText>The survey collected prospectively clinical data and technical characteristics of ICD implants on the basis of EURID form.</AbstractText>The number of patients was 1,274 in the HCM group, 520 in the ARVD/C group, 460 in the IDIO-VA group, and 245 in the LQT group. Primary prevention involved 29.5% of patients in the HCM group, 15.9% in the ARVD/C group, 16.9% in the IDIO-VA group, and 16.6% in the LQT group, respectively. Ventricular tachycardia and ventricular fibrillation were reported in 49.0% and 24.8% in the HCM group, 72.9% and 20.0% in the ARVD/C group, 48.2% and 42.9% in the IDIO-VA group, and 21.2% and 61.6% in the LQT group, respectively. Single-, dual-, and triple-chamber ICDs were implanted in 41.5%, 47.6%, and 10.9% in the HCM group; 57.9%, 36.7%, and 5.4% in the ARVD/C group; 55.0%, 45.0%, and 0% in the IDIO-VA group; and 57.4%, 42.6%, and 0% in LQT group, respectively.</AbstractText>ICD therapies in the years 2001-6 for patients with inherited arrhythmia syndromes were utilized in Italy in a still-limited number of patients. Secondary prevention represented the major indication for ICD implant and the majority of patients were treated by single-chamber ICDs.</AbstractText> |
6,773 | Search for the optimal right ventricular pacing site: design and implementation of three randomized multicenter clinical trials. | The optimal site to permanently pace the right ventricle (RV) has yet to be determined. To address this issue, three randomized prospective multicenter clinical trials are in progress comparing the long-term effects of RV apical versus septal pacing on left ventricular (LV) function. The three trials are Optimize RV Selective Site Pacing Clinical Trial (Optimize RV), Right Ventricular Apical and High Septal Pacing to Preserve Left Ventricular Function (Protect Pace), and Right Ventricular Apical versus Septal Pacing (RASP).</AbstractText>Patients that require frequent or continuous ventricular pacing are randomized to RV apical or septal pacing. Optimize RV excludes patients with LV ejection fraction <40% prior to implantation, whereas the other trials include patients regardless of baseline LV systolic function. The RV septal lead is positioned in the mid-septum in Optimize RV, the high septum in Protect Pace, and the mid-septal inflow tract in RASP. Lead position is confirmed by fluoroscopy in two planes and adjudicated by a blinded panel. The combined trials will follow approximately 800 patients for up to 3 years.</AbstractText>The primary outcome in each trial is LV ejection fraction evaluated by radionuclide ventriculography or echocardiography. Secondary outcomes include echo-based measurements of ventricular/atrial remodeling, 6-minute hall walk distance, brain natriuretic peptide levels, and clinical events (atrial tachyarrhythmias, heart failure, stroke, or death).</AbstractText>These selective site ventricular pacing trials should provide evidence of the importance of RV pacing site in the long-term preservation of LV function in patients that require ventricular pacing and help to clarify the optimal RV pacing site.</AbstractText> |
6,774 | I(Kur)/Kv1.5 channel blockers for the treatment of atrial fibrillation. | Atrial fibrillation (AF) is the most common sustained arrhythmia. Anti-arrhythmic drugs remain the mainstay of therapy, but the available class I and III anti-arrhythmic drugs are only moderately effective in long-term restoring/maintaining sinus rhythm (SR) and can produce potentially fatal ventricular pro-arrhythmia. In an attempt to identify safer and more effective anti-arrhythmic drugs, drug discovery efforts have focused on 'atrial selective drugs' that target cardiac ion channel(s) that are exclusively or predominantly expressed in the atria. The ultra-rapid activating delayed rectifier K(+) current (I(Kur)), carried by Kv1.5 channels, is a major repolarizing current in human atria, but seems to play no role in the ventricle. This finding offers the possibility of developing selective I(Kur) blockers to restore and maintain SR without a risk of ventricular pro-arrhythmia. Several I(Kur) blockers are now being developed but clinical data are still limited, so the precise role of these agents in the treatment of AF remains to be defined. In this review we analyze the possible advantages and disadvantages of the developmental I(Kur) blockers as they represent the first step for the development of potential atrial selective drugs for a more effective and safer treatment and prevention of AF. |
6,775 | [Molecular mechanism of the changes in ventricular electrical remodeling caused by mechano-electrical feedback in rabbits with congestive heart failure]. | This study sought to explore the relationship between the change in ventricular electrical remodeling caused by mechano-electrical feedback and the expression of L-type Ca2+ -channel and/or sarcoplasmic reticulum Ca2+ -ATPase in the rabbits with congestive heart failure (CHF). 138 rabbits were divided into two groups (CHF and control). We measured the ventricular monophasic action potential duration (MAPD) and ventricular effective refractory period (VERP) during ventricular pacing at the stimulus frequency of 220/240/260 bpm in these rabbits. Rapid atrial pacing (260/min) was given for 30 minutes. The MAPD and VERP were measured again. Then ventricular fibrillation was induced by S1S2S3 program stimulation. We extracted the total RNA from the myocardium respectively and detected L-type Ca2+ -channel mRNA and sarcoplasmic reticulum Ca2+ -ATPase mRNA by use of Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR). In group CHF, with the increasing of preload/afterload, L-type Ca2+ -channel mRNA was up regulated after rapid atrial pacing when compared with that in control groups (P < 0.05). There was no significant change in sarcoplasmic reticulum Ca2+ -ATPase mRNA after rapid atrial pacing when compared with controls (P > or = 0.05). The changes in MAPD90 and VERP were related with the extent of L-type Ca2+ -channel mRNA up regulation. But the changes in MAPD90 and VERP were not significantly related with the extent of sarcoplasmic reticulum Ca2+ -ATPase mRNA up regulation. These findings suggest that Mechano-Electrical Feedback could increase the regional changes of ventricular electrical remodeling in rabbits with CHF and so to predispose them to ventricular arrhythmia. The changes may be related with the up regulation of L-type Ca2+ -channel mRNA, but not with sarcoplasmic reticulum Ca2+ -ATPase mRNA. |
6,776 | [Specific effects of selective anxiolytic afobazole on the cardiovascular system]. | Experiments in narcotized rats showed the new selective anxiolytic afobazole, a derivative of 2-mercaptobenzimidazole, to cause a small bradycardia with almost no effect on the important parameters of heart hemodynamics and cardiac performance such as the arterial pressure, cardiac output, and mean aorta blood flow acceleration. Afobazole decreased the rate of ventricular fibrillations during 7-min occlusion followed by 3-min reperfusion of the left coronary artery in narcotized rats. Afobazole administered in rats for 21 days under conditions of experimental myocardial infarction had no effect on the pump and contractile cardiac functions. The drug normalized the reaction of mean aorta blood flow acceleration to the volume load suppressed by myocardial infarction, which was indicative of an increase in the adaptive capacity of myocardium. |
6,777 | Atrial Fibrillation: The New Epidemic of the Ageing World. | The prevalence of atrial fibrillation (AF) increases with age. As the population ages, the burden of AF increases. AF is associated with an increased incidence of mortality, stroke, and coronary events compared to sinus rhythm. AF with a rapid ventricular rate may cause a tachycardia-related cardiomyopathy. Immediate direct-current (DC) cardioversion should be performed in patients with AF and acute myocardial infarction, chest pain due to myocardial ischemia, hypotension, severe heart failure, or syncope. Intravenous beta blockers, diltiazem, or verapamil may be administered to reduce immediately a very rapid ventricular rate in AF. An oral beta blocker, verapamil, or diltiazem should be used in persons with AF if a fast ventricular rate occurs at rest or during exercise despite digoxin. Amiodarone may be used in selected patients with symptomatic life-threatening AF refractory to other drugs. Digoxin should not be used to treat patients with paroxysmal AF. Nondrug therapies should be performed in patients with symptomatic AF in whom a rapid ventricular rate cannot be slowed by drugs. Paroxysmal AF associated with the tachycardia-bradycardia syndrome should be treated with a permanent pacemaker in combination with drugs. A permanent pacemaker should be implanted in patients with AF and symptoms such as dizziness or syncope associated with ventricular pauses greater than 3 seconds which are not drug-induced. Elective DC cardioversion has a higher success rate and a lower incidence of cardiac adverse effects than does medical cardioversion in converting AF to sinus rhythm. Unless transesophageal echocardiography has shown no thrombus in the left atrial appendage before cardioversion, oral warfarin should be given for 3 weeks before elective DC or drug cardioversion of AF and continued for at least 4 weeks after maintenance of sinus rhythm. Many cardiologists prefer, especially in elderly patients , ventricular rate control plus warfarin rather than maintaining sinus rhythm with antiarrhythmic drugs. Patients with chronic or paroxysmal AF at high risk for stroke should be treated with long-term warfarin to achieve an International Normalized Ratio of 2.0 to 3.0. Patients with AF at low risk for stroke or with contraindications to warfarin should be treated with aspirin 325 mg daily. |
6,778 | A Comparative Study to Determine the Effect of Intravenous Magnesium on Postoperative Bleeding after on Pump CABG in Patients Receiving Pre-Operative Aspirin. | Hypomagnesaemia is a common complication after cardiopulmonary bypass (CPB) and predisposes to the development of cardiac arrhythmias. Previous studies showed that intravenous magnesium reduces the incidence of postoperative cardiac arrhythmias but it also inhibits platelet function. Our aim was to compare the postoperative blood loss in patients not receiving magnesium after CPB with the group who received magnesium and to compare the requirement of blood, fresh frozen plasma (FFP) and platelets within 24 hours after surgery. This prospective randomized controlled study was conducted in 80 adult patients on oral aspirin undergoing elective CABG requiring CPB. Group A patients had not received magnesium infusion after recovery from CPB. Group B patients received magnesium infusion after recovery from CPB. Postoperative bleeding was assessed in both the groups. All the data were statistically analyzed. There was a insignificant increase in 24 hours postoperative drainage in magnesium recipient group compared to control group (p>0.05). Requirements of blood and blood products to maintain haematocrit and coagulation profile revealed insignificant (p > 0.05). Increase in requirement of PRC, FFP and platelets in magnesium recipient patients than the control group. Incidence of atrial fibrillation (Gr A 2.5%, Gr B 2.5%) and atrial extrasystoles (Gr A 2.5%, Gr B 10%) revealed comparable (p > 0.05) between the groups, but incidence of ventricular arrhythmias were significantly (p<0.05) high in the patients of Gr A(17.5%) than Gr B(5%). To conclude, magnesium may be administered to patients who continue pre-operative aspirin to undergo on-pump CABG surgery. |
6,779 | Role of magnesium in preventing post-operative atrial fibrillation after coronary artery bypass surgery. | To assess the role of 3 days of magnesium infusion after coronary artery bypass graft (CABG) surgery in preventing postoperative atrial fibrillation (AF).</AbstractText>Armed Forces Institute of Cardiology (AFIC) & National Institute of Heart Diseases (NIHD), Rawalpindi, from July 2006 to June 2007.</AbstractText>Prospective, randomized, non-blinded.</AbstractText>All patients undergoing isolated, initial CABG surgery, and having sinus rhythm before surgery were alternatively randomized into the study or the control group. The exclusion criteria included: history of AF, implanted pacemaker, myocardial infarction postoperatively, use of left ventricular assist devices and renal failure. The patients in the study group received 10 mmol of magnesium sulphate (2.47 gm) dissolved in 100 ml of saline solution infused intravenously over 4 hours, for 3 days. The end point was development of AF for at least 15 minutes or more, or if an episode of AF had to be treated because of symptoms.</AbstractText>A total of 220 patients were included in the study, 110 in each group. The incidence of AF was 9% in patients who received the three days of magnesium infusion. The patients without magnesium had an AF incidence of 23% (p < 0.001). The hospital stay was also less in the treated group (p = 0.055).</AbstractText>A 3-days postoperative infusion of magnesium is safe and effective in reduction of possibly life-threatening AF, in patients undergoing primary coronary artery bypass surgery.</AbstractText> |
6,780 | Circadian patterns in the occurrence of malignant ventricular tachyarrhythmias triggering defibrillator interventions in patients with hypertrophic cardiomyopathy. | Sudden death in hypertrophic cardiomyopathy (HCM) has been reported to occur most frequently in the early morning hours, similar to the pattern observed in ischemic heart disease. However, little is known about the circadian pattern of life-threatening arrhythmias in HCM in the contemporary era of the implantable cardioverter-defibrillator (ICD).</AbstractText>The purpose of this study was to determine the time of day when appropriate device interventions occur for ventricular tachycardia (VT)/ventricular fibrillation (VF) in HCM patients.</AbstractText>Among 63 patients with HCM and appropriate device interventions, 126 intracardiac electrograms were assessed for the hourly distribution of VT/VF.</AbstractText>One or more arrhythmic episodes occurred in each hour of the day, and a modest pattern of circadian variability was evident. VT/VF episodes were more common in the afternoon and evening hours from noon to midnight (64%) than in the other 12-hour period (36%; P = .008), with the suggestion of a peak at 2 to 4 PM. A sizeable proportion of events (27%) occurred during the potential sleeping hours of 11 PM and 7 AM.</AbstractText>In high-risk HCM patients, the afternoon and evening circadian periodicity of ventricular tachyarrhythmias (terminated by the ICD) underscores the largely unpredictable nature of the electrophysiologic substrate in this disease, and differs from the pattern of early morning cardiovascular events reported in ischemic heart disease. These observations also suggest that home automatic defibrillator strategies for sudden death prevention are unlikely to be effective in HCM.</AbstractText> |
6,781 | Influence of patient age and sex on delivery of guideline-recommended heart failure care in the outpatient cardiology practice setting: findings from IMPROVE HF. | The influence of patient age and sex on delivery of guideline-recommended heart failure (HF) therapies in contemporary outpatient settings has not been well studied. The Registry to Improve the Use of Evidence-Based Heart Failure Therapies in the Outpatient Setting (IMPROVE HF) is a prospective cohort study designed to characterize current management of outpatients with chronic HF and left ventricular ejection fraction < or =35%.</AbstractText>Baseline data for eligible patients with systolic HF in a national registry of 167 US outpatient cardiology practices were collected by trained chart abstractors. Data were stratified and analyzed as male/female and by age tertiles with generalized estimating equation models constructed for 7 care measures.</AbstractText>A total of 15,381 patients were enrolled, with 8,770 (71.1%) of these male. Median age of female patients was 72.0 and 70.0 for males. Use of angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, beta-blockers, aldosterone inhibitors, and cardiac resynchronization therapy was not significantly different between male and female patients, but rates for implantable cardioverter defibrillators, anticoagulation therapy for atrial fibrillation, and HF education were significantly lower for females. After adjusting for patient and practice characteristics, 3 of 7 measures significantly differed by patient sex, and 6 of 7 measures by age. Older patients, particularly older women, were significantly less likely to receive guideline-indicated HF therapies.</AbstractText>Patient age and sex were independently associated with reduced rates of some, but not all, HF therapies in outpatient cardiology practices. Older women are especially at risk. Further research is needed to understand the causes and consequences of these age- and sex-related differences in care.</AbstractText> |
6,782 | Evidence that the degree of obstructive sleep apnea may not increase myocardial ischemia and arrhythmias in patients with stable coronary artery disease. | There is controversy regarding whether obstructive sleep apnea is responsible for triggering myocardial ischemia, arrhythmias and heart rate variability in patients with coronary artery disease.</AbstractText>The objective of this study was to identify relationships between sleep apnea, myocardial ischemia and cardiac arrhythmia in patients with coronary artery disease.</AbstractText>Fifty-three patients with stable coronary disease underwent simultaneous polysomnography and electrocardiographic Holter recording. The apnea-hypopnea index (AHI) was defined as the number of apneas/hypopneas per hour of sleep. Patients were divided into a Control group (AHI15, n=23 pts) and an Apnea group (AHI>15, n=30 pts). A subgroup of 13 patients with an AHI>30 (Severe Apnea group) was also studied. We analyzed ischemic episodes (ST-segment depressions >1 mm, > 1 min), heart rate variability and the occurrence of arrhythmias during wakefulness and sleep.</AbstractText>Baseline clinical characteristics among the groups were similar except for higher blood pressure in the Apnea groups (p<0.05). Myocardial ischemia was recorded in 39 (73.6%) patients. The number and duration of ischemic episodes significantly decreased during sleep in all groups; during wakefulness, patients with severe apnea exhibited fewer and shorter episodes in comparison with the controls. There were no significant differences in heart rate variability or in the occurrence of arrhythmias among the groups. Malignant ventricular arrhythmias, atrial fibrillation/flutter, bradycardia and high-degree atrioventricular blocks were not detected.</AbstractText>Obstructive sleep apnea was not related to myocardial ischemia, heart rate variability or arrhythmias in patients with stable coronary artery disease and did not alter the circadian pattern of myocardial ischemia.</AbstractText> |
6,783 | Minimally invasive mitral valve surgery through right thoracotomy in patients with patent coronary artery bypass grafts. | We report our institutional experience, with 25 consecutive patients with patent coronary artery bypass grafts (71.8+/-12.7 years), who underwent video-assisted minithoracotomic approach for mitral valve surgery. The surgical technique includes: right minithoracotomy, femoral cannulation and hypothermic ventricular fibrillation. Mean preoperative EuroSCORE was 10.2+/-2.4 and mean ejection fraction was 45+/-9%. Operative mortality was 4% (1/25). No patient required a conversion to sternotomy. Procedures performed were: mitral valve repair in 15 patients (60%), replacement in 10 (40%) and associated tricuspid repair in seven (28%). Mean blood transfusion was 1.2 package/patient. No cardiological, neurological, vascular and wound complications were observed. Postoperative major morbidity includes: severe pulmonary dysfunction in two patients (8%) and acute renal failure in one (4%). Mean ICU and hospital stay were 3.4+/-2.9 and 10.6+/-7.9 days. Echocardiographic follow-up (22.8+/-14.9 months) revealed trace or mild mitral valve regurgitation in all the mitral repair patients. When interrogated, all the surviving patients preferred the minithoracotomic approach rather than the sternotomy. In conclusion, minimally invasive right thoracotomy can be safely performed in patients with functioning coronary bypass grafts requiring mitral valve operation. Low blood transfusion, the avoidance of deep wound infection and the high patient satisfaction are the main advantages of this approach. |
6,784 | Physiology and pathology of TASER electronic control devices. | TASER ECDs (electronic control device) are small, battery powered, handheld devices. They deliver short duration, low energy pulses to stimulate motor neurons, causing transient paralysis. While the experience is painful, proper use of the device is rarely associated with significant side effects in spite of 1070 human worldwide exposures daily. In fact, there have been more than 780,000 training exposures and 630,000 field uses (total of over 1.4 million human uses) without any credible evidence of a resulting cardiac arrhythmia. In this article we describe the mechanisms by which the device operates, and review possible morbidities. |
6,785 | Does preoperative atrial fibrillation increase the risk for mortality and morbidity after coronary artery bypass grafting? | Preoperative atrial fibrillation has been associated with less favorable outcomes in patients undergoing coronary artery bypass grafting. However, it was never investigated in a large cohort of patients using a national database. This study aims to (1) identify the effect of atrial fibrillation on operative mortality and morbidity in patients undergoing isolated coronary artery bypass grafting and (2) identify the potential effect of atrial fibrillation on patients with decreased left ventricular ejection fraction (<or=40%).</AbstractText>The Society of Thoracic Surgeons National Adult Cardiac Surgery Database was used for patients with coronary artery disease undergoing isolated coronary artery bypass grafting (n = 281,567). The association between atrial fibrillation and outcomes was estimated within 3 categories of low (ejection fraction, <40%), moderate (ejection fraction, 40%-55%), or normal (ejection fraction, >55%) systolic function.</AbstractText>Patients with atrial fibrillation were found to be older and have a higher incidence of comorbidities. A higher incidence of all major complications and mortality after surgical intervention was documented. An interaction between atrial fibrillation and an ejection fraction of greater than 40% for mortality, stroke, prolonged ventilation, and prolonged length of stay was identified.</AbstractText>Our findings suggest that preoperative atrial fibrillation is associated with an increased risk for perioperative mortality and morbidity in patients undergoing coronary artery bypass grafting. The negative effect of atrial fibrillation might be more significant in patients undergoing coronary artery bypass grafting with an ejection fraction of greater than 40%. Both the EuroSCORE and, until recently, the Society of Thoracic Surgeons risk calculator do not include atrial fibrillation as a potential risk modifier; however, based on this study, it should be identified as a variable to be investigated and incorporated into future risk calculators.</AbstractText> |
6,786 | Relation of left atrial volume from three-dimensional computed tomography to atrial fibrillation recurrence following ablation. | The effect of left atrial (LA) structural remodeling and dilatation on the outcome of ablation of atrial fibrillation (AF) remains unknown. We correlated potential prognostic markers of AF ablation, including LA volume from computed tomography, with AF recurrence after ablation. We studied 73 consecutive patients (52 with paroxysmal AF, 21 with persistent AF) undergoing AF ablation. LA volume was calculated by axial slice summation from 3-dimensional computed tomography. Follow-up was through 12 months, with success of ablation determined by electrocardiography and lack of symptoms (unless symptoms proved not AF by Holter monitor). Overall procedure success was 66% (including 15% repeat ablations, 12% on antiarrhythmics). Pulmonary vein isolation was performed, with additional linear ablation in 44 (60%). Mean LA volume (95% confidence interval) for those with recurrent AF was 119 ml (104 to 135) versus 98 ml (90 to 106) for no recurrence (p = 0.01, rank-sum test). Wide variation in LA volume occurred in the 2 groups, but, of the 15% of patients with very large LA volumes (>135 ml), 82% had recurrent AF. A cutpoint of 135 ml yields 36% sensitivity and 96% specificity for recurrence. In multivariable regression analysis, only LA volume and number of cardiovascular co-morbidities were associated with more recurrence (p = 0.02 and p = 0.03, respectively). In conclusion, LA volume varies greatly in those with and without successful AF ablations, mean LA volume is significantly larger in those with recurrence, and patients with LA volumes >135 ml are very likely to develop recurrent AF. |
6,787 | Cardiac arrest survival after implementation of automated external defibrillator technology in the in-hospital setting. | Survival from ventricular tachycardia (VT) or ventricular fibrillation (VF) arrest is inversely related to delay to defibrillation. The automated external defibrillator (AED) has improved survival after out-of-hospital VT/VF arrest by decreasing time to defibrillation. The purpose of this study was to determine whether survival to discharge after in-hospital cardiac arrest caused by VT/VF could be improved via an institution-wide change from a standard monophasic defibrillator to a biphasic defibrillator with AED capability.</AbstractText>After extensive staff education, all standard defibrillators were replaced by AEDs at a single institution. Outcomes were analyzed for 1 year before the change and 1 year after the change using a prospective database. In patients whose initial rhythm was VT/VF, AEDs were not associated with improvement in time to first shock (median 1 minute for both cohorts, p = 0.79) or survival to discharge (31% vs. 29%, p = 0.8) compared with standard defibrillators. In patients whose initial rhythm was asystole or pulseless electrical activity, AEDs were associated with a significant decrease in survival (15%) compared with standard defibrillators (23%, p = 0.04). The overall AED cohort showed no difference in survival to discharge compared with the standard cohort (18% vs. 23%, p = 0.09).</AbstractText>Replacement of standard monophasic defibrillators with biphasic AEDs was associated with unchanged survival after in-hospital VT/VF arrest and decreased survival after in-hospital asystole or pulseless electrical activity arrest.</AbstractText> |
6,788 | NT-proBNP for pulmonologists: not only a rule-out test for systolic heart failure but also a global marker of heart disease. | Recognizing heart disease is relevant to pulmonologists because many patients suspected to have dyspnea of pulmonary origin harbor heart disease.</AbstractText>To investigate the role of N-terminal pro-brain natriuretric peptide (NT-proBNP) in identifying heart disease and cardiac causes of dyspnea among patients referred for evaluation by a pulmonologist.</AbstractText>697 consecutive outpatients (aged 57.5 +/- 16.4 years) with chronic dyspnea prospectively underwent a diagnostic work-up for heart and lung diseases.</AbstractText>The prevalence of patients with heart disease was 25.3%. The cardiac findings were placed into 6 groups which were associated with an increase in NT-proBNP in the following order: (1) left ventricular hypertrophy [regression coefficient (beta) = 0.33, p = 0.03]; (2) exercise-induced myocardial ischemia (beta = 0.73, p = 0.02);(3) valvular or congenital heart disease or pericardial effusion (beta = 0.93, p < 0.0001); (4) pulmonary hypertension (beta = 1.14, p < 0.0001); (5) atrial fibrillation or left bundle branch block (beta = 1.22, p < 0.0001), and (6) left ventricular systolic dysfunction (beta = 1.94, p < 0.0001). Using predefined cut-off values of 93 pg/ml (men) and 144 pg/ml (women), sensitivity was 0.75 and specificity was 0.79 for identifying heart disease. The negative predictive value was 0.90. If heart disease had to be considered as a cause of the dyspnea, sensitivity and the negative predictive value went up to 0.90 and 0.97, respectively.</AbstractText>NT-proBNP performs well as a test for ruling out cardiac dyspnea. It is also useful as a rule-in test for heart disease, which enables the pulmonologist to appropriately select candidates for in-depth evaluation by cardiology.</AbstractText>Copyright 2009 S. Karger AG, Basel.</CopyrightInformation> |
6,789 | Clinical impact of evaluation of cardiovascular control by novel methods of heart rate dynamics. | Heart rate variability (HRV) has been conventionally analysed with time- and frequency-domain methods, which measure the overall magnitude of RR interval fluctuations around its mean value or the magnitude of fluctuations in some predetermined frequencies. Analysis of heart rate dynamics by novel methods, such as heart rate turbulence after ventricular premature beats, deceleration capacity of heart rate and methods based on chaos theory and nonlinear system theory, have gained recent interest. Recent observational studies have suggested that some indices describing nonlinear heart rate dynamics, such as fractal scaling exponents, heart rate turbulence and deceleration capacity, may provide useful prognostic information in various clinical settings and their reproducibility may be better than that of traditional indices. For example, the short-term fractal scaling exponent measured by the detrended fluctuation analysis method has been shown to predict fatal cardiovascular events in various populations. Similarly, heart rate turbulence and deceleration capacity have performed better than traditional HRV measures in predicting mortality in post-infarction patients. Approximate entropy, a nonlinear index of heart rate dynamics, which describes the complexity of RR interval behaviour, has provided information on the vulnerability to atrial fibrillation. There are many other nonlinear indices which also give information on the characteristics of heart rate dynamics, but their clinical usefulness is not as well established. Although the concepts of nonlinear dynamics, fractal mathematics and complexity measures of heart rate behaviour, heart rate turbulence, deceleration capacity in relation to cardiovascular physiology or various cardiovascular events are still far away from clinical medicine, they are a fruitful area for research to expand our knowledge concerning the behaviour of cardiovascular oscillations in normal healthy conditions as well as in disease states. |
6,790 | Mode and mechanisms of death after orthotopic heart transplantation. | Ventricular fibrillation (VF) is the primary mechanism of cardiac arrest in the vast majority of sudden death patients. Whether similar modes and mechanisms of death can be generalized to denervated hearts in orthotopic heart transplantation (OHT) patients is unknown.</AbstractText>The purpose of this study was to determine the mode and mechanisms of death in patients who have undergone cardiac transplantation.</AbstractText>We analyzed the outcomes of 628 patients who underwent OHT between January 1994 and December 2004. The mode of death was classified as either sudden death (SD) or non-sudden death (NSD). The first documented rhythm taken at the time of arrest was also reviewed to determine the mechanism of cardiac arrest.</AbstractText>During a mean follow-up of 76 months, 194 patients died. Of these, the mode of death could be determined in 116 patients (60%). Forty-one patients (35%) died of SD, and 75 patients (65%) died of NSD. The first documented rhythm of death was available in 91 patients (26 SD and 65 NSD). The terminal rhythms in patients who died suddenly were: asystole (34%), pulseless electrical activity (PEA) (20%), and VF (10%). In NSD patients, the terminal rhythms were asystole (73%), followed by VF (7%), and PEA (7%), P < .001 compared with SD patients.</AbstractText>SD represented the mode of death in 35% of OHT patients. The main mechanisms underlying SD in this population were asystole and PEA, suggesting that denervation of the donor heart, among other post-transplantation changes, may alter susceptibility to VF.</AbstractText> |
6,791 | Differential effects of cardiac sodium channel mutations on initiation of ventricular arrhythmias in patients with Brugada syndrome. | Premature ventricular contractions (PVCs) do not occur frequently but can induce ventricular fibrillation (VF) in patients with Brugada syndrome. The effect of SCN5A mutation on the onset of ventricular arrhythmias is unknown.</AbstractText>The purpose of this study was to evaluate PVC morphology and onset of VF in patients with Brugada syndrome.</AbstractText>Morphology of PVCs was evaluated by 12-lead ECG in 32 patients with Brugada syndrome. Patients had spontaneous ventricular arrhythmia (n = 17) or sodium channel blocker-induced ventricular arrhythmia (n = 19). Patients were classified into two groups according to the existence of SCN5A mutation (22 mutation negative, 10 mutation positive).</AbstractText>Patients without mutation often had PVCs of left bundle branch block (LBBB) morphology (82%), especially with inferior axis (77%). Patients with mutation had PVCs of both right bundle branch block (36%) and LBBB (64%) morphologies. Only two patients with mutation had PVCs of LBBB, inferior-axis morphology.</AbstractText>Patients without SCN5A mutation often had PVCs of LBBB, inferior-axis morphology, suggesting a right ventricular outflow tract origin. Patients with SCN5A mutations had PVCs that originated from both the right and left ventricles.</AbstractText> |
6,792 | Atrial cellular electrophysiological changes in patients with ventricular dysfunction may predispose to AF. | Left ventricular systolic dysfunction (LVSD) is a risk factor for atrial fibrillation (AF), but the atrial cellular electrophysiological mechanisms in humans are unclear.</AbstractText>This study sought to investigate whether LVSD in patients who are in sinus rhythm (SR) is associated with atrial cellular electrophysiological changes that could predispose to AF.</AbstractText>Right atrial myocytes were obtained from 214 consenting patients in SR who were undergoing cardiac surgery. Action potentials or ion currents were measured using the whole-cell-patch clamp technique.</AbstractText>The presence of moderate or severe LVSD was associated with a shortened atrial cellular effective refractory period (ERP) (209 +/- 8 ms; 52 cells, 18 patients vs 233 +/- 7 ms; 134 cells, 49 patients; P <0.05); confirmed by multiple linear regression analysis. The left ventricular ejection fraction (LVEF) was markedly lower in patients with moderate or severe LVSD (36% +/- 4%, n = 15) than in those without LVSD (62% +/- 2%, n = 31; P <0.05). In cells from patients with LVEF <or= 45%, the ERP and action potential duration at 90% repolarization were shorter than in those from patients with LVEF > 45%, by 24% and 18%, respectively. The LVEF and ERP were positively correlated (r = 0.65, P <0.05). The L-type calcium ion current, inward rectifier potassium ion current, and sustained outward ion current were unaffected by LVSD. The transient outward potassium ion current was decreased by 34%, with a positive shift in its activation voltage, and no change in its decay kinetics.</AbstractText>LVSD in patients in SR is independently associated with a shortening of the atrial cellular ERP, which may be expected to contribute to a predisposition to AF.</AbstractText> |
6,793 | Recent advances in the management of coronary artery disease: highlights from the literature. | The recent advances in the multidisciplinary management of coronary artery disease (CAD) have been significant. The assessment of patients before percutaneous coronary intervention is likely to change significantly. National compliance with clinical guidelines in the preprocedural assessment of myocardial ischemia should be encouraged. Multislice computed tomographic coronary angiography continues to improve and is already an excellent screening test for CAD. Coronary stenting has an increasing role in multivessel and left main CAD, although further outcome trials are indicated, especially in the elderly. Although off-pump coronary artery bypass graft (CABG) surgery reduces postoperative atrial fibrillation, further major outcome advantages have not been shown in comprehensive meta-analyses when compared with on-pump CABG surgery. Although an intra-aortic balloon pump reduces mortality in high-risk CABG surgery, it may be replaced gradually by the percutaneous left ventricular-assist device, which has shown clinical benefit in this challenging setting. Statin therapy significantly improves clinical outcome after CABG surgery, even when begun postoperatively. There is strong evidence that, unless contraindicated, all CABG patients should receive statin therapy. Clopidogrel therapy just before CABG surgery is still associated with prolonged hospital stay because of significant bleeding complications. This risk will be exacerbated with the advent of the more potent platelet inhibitor, prasugrel. There is a clinical necessity for readily reversible platelet blockade to minimize the bleeding risks in CABG surgery. |
6,794 | Coronary angiography predicts improved outcome following cardiac arrest: propensity-adjusted analysis. | Determine if clinical parameters of resuscitated patients predict coronary angiography (CATH) performance and if receiving CATH after cardiac arrest is associated with outcome.</AbstractText>CATH is associated with survival in patients suffering out-of-hospital cardiac arrest (OHCA) from ventricular fibrillation or ventricular tachycardia(VF/VT). Its effect on outcome in other cohorts is unknown.</AbstractText>Chart review of resuscitated cardiac arrest patients between 2005 and 2007.</AbstractText>immediate withdrawal of care, hemodynamic collapse, or neurologic exam under sedation. Clinical parameters included Glasgow Coma Scale (GCS) arrest location, presenting rhythm, age, and acute ischemic ECG changes (new left bundle branch block or ST-elevation myocardial infarction-STEMI). Logistic regression identified clinical parameters predicting CATH. The association between CATH and good outcome (discharge home or to acute rehabilitation facility) was determined using logistic regression adjusting for likelihood of receiving CATH via propensity score.</AbstractText>Of the 241 patients, 96 (40%) received CATH. Significant disease (>or=70% stenosis) of >or=1 coronary arteries was identified in 69% of patients including 57% of patients without acute ischemic ECG changes. Unadjusted predictors of CATH were sex, method of arrival, OHCA, presenting rhythm, acute ischemic ECG changes, and GCS. Propensity adjusted logistic regression demonstrated an association between CATH and good outcome (OR 2.16; 95% CI 1.12, 4.19; P<0.02).</AbstractText>CATH is more likely to be performed in certain patients and identifies a significant number of high-grade stenoses in this population. Receiving CATH was independently associated with good outcome.</AbstractText> |
6,795 | Acute myocardial infarction with changing axis deviation. | Changing axis deviation has been rarely reported also during atrial fibrillation or atrial flutter. Changing axis deviation has been rarely reported also during acute myocardial infarction associated with atrial fibrillation. Isolated left posterior hemiblock is a very rare finding but the evidence of transient right axis deviation with a left posterior hemiblock pattern has been reported during acute anterior myocardial infarction as related with significant right coronary artery obstruction and collateral circulation between the left coronary system and the posterior descending artery. Left anterior hemiblock development during acute inferior myocardial infarction can be an indicator of left anterior descending coronary artery lesions, multivessel coronary artery disease, and impaired left ventricular systolic function. We present a case of changing axis deviation in a 62-year-old Italian man with acute myocardial infarction. Also this case focuses attention on changing axis deviation during acute myocardial infarction. |
6,796 | Cerebral infarction and right ventricular noncompaction. | A 26-year-old man admitted with dysphasia and bilateral headache for three days. He had no known risk factors for stroke. Transthoracic two-dimensional echocardiography showed prominent trabeculations, with deep intertrabecular recesses in apex of the right ventricle. The multi-detector-row spiral cerebral computerized tomography revealed a little infarction in bilateral temporal and frontal lobe. The main mechanisms of neurovascular complications in NVM may be related to development of thrombi in the intertrabecular space. Extensively trabeculated ventricle, depressed systolic function, and/or the development of atrial fibrillation are the causes for thrombus formation7. Embolic stroke has been only rarely described in association with NVM9. However, whether NVM is a risk factor for stroke is controversially discussed. Prevention of embolic complications is an important management issue, and several authors have recommended long-term prophylactic anticoagulation for patients in NVM with atrial fibrillation and severe systolic dysfunction. The field of neurovascular complications, and specially cerebral infarction, in NVM of right ventricular remains not yet fully understood. |
6,797 | Post induction arrhythmia in a renal patient: an unexpected risk factor. | A 44 year-old woman was anaesthetised for a transplant nephrectomy. About 10 min after induction of anaesthesia she had several runs of ventricular tachycardia followed by ventricular fibrillation requiring 30 s of cardiopulmonary resuscitation, after which she reverted to sinus rhythm. Review of her chest X-ray, suggested that the haemodialysis catheter (Permcath) position may have precipitated this event. However, subsequent investigation found that she had toxic serum levels of sotalol, with a prolonged corrected QT interval on the electrocardiogram. She was started on sotalol while her renal graft was functioning well but it was not reviewed when the graft started to fail and she had to commence haemodialysis. This led to the accumulation of sotalol and explains her serum sotalol value of 7.1 mg x l(-1) on the day of the event. Concentrations greater than 2.5 mg x l(-1) are generally considered toxic. |
6,798 | Redox regulation, NF-kappaB, and atrial fibrillation. | Atrial fibrillation (AF) is the most common clinically encountered abnormal heart beat. It is associated with an increased risk of stroke and symptoms of heart failure. Current therapies are directed toward controlling the rate of ventricular activation and preventing strokes through anticoagulation. Attempts at suppressing the arrhythmia are often ineffective, in part because the underlying pathogenesis is poorly understood. Recently, structural and electrical remodeling has been shown to occur during AF. These changes involve alterations in gene regulation and help perpetuate the arrhythmia. Some signals for remodeling are have been identified. Moreover, AF is associated with oxidative stress, and this redox imbalance may contribute to the altered gene regulation. One likely mediator of this change in transcriptional regulation is the redox sensitive transcription factor, nuclear factor-kappaB (NF-kappaB). Recently, NF-kappaB has been shown to downregulate transcription of the cardiac sodium channel in response to oxidative stress. NF-kappaB may contribute to the regulation of other ion channels, transcription factors, or splicing factors altered in AF and may represent a therapeutic target in AF management. |
6,799 | [Stroke and hypertension]. | Arterial hypertension is the most important risk factor for stroke. Many interventional trials have unambiguously proven the benefit of antihypertensive therapy in both primary and secondary prevention for all age categories. No recommendation for any single antihypertensive substance for the primary prevention of stroke exists. Achieving the therapeutic goal (normotension) is the crucial factor. In most patients, multiple combinations of antihypertensive drugs are required to do this. For high-risk patients and in secondary prevention, substances inhibiting the renin-angiotensin-system, especially combined with calcium antagonists and indapamid, may be advantageous, while beta-blockers appear to be less well suited. In patients suffering from left-ventricular hypertrophy or atrial fibrillation, sartanes are the best-documented drug class. As TIA or stroke will often disturb the normal circadian rhythm of blood pressure and eliminate the usual night-time drop, monitoring of the therapeutic results must include ambulatory 24h measurements. The interrelation between vascular dementia and hypertension is by now also considered proven. An early start of antihypertensive treatment can prevent the development of dementia and impaired cognitive function. |
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