Circulation
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Randomized Controlled Trial Multicenter Study Comparative Study Clinical Trial
Effect of implantable defibrillators on arrhythmic events and mortality in the multicenter unsustained tachycardia trial.
The Multicenter Unsustained Tachycardia Trial (MUSTT) was designed to evaluate an antiarrhythmic treatment strategy, including drugs and implantable defibrillators (ICDs), guided by electrophysiological (EP) testing. We performed several statistical analyses to assess the contribution of defibrillators to the observed treatment benefit. ⋯ The benefit of EP-guided antiarrhythmic therapy observed in MUSTT was due to improved outcomes among patients who received an ICD but not among patients who received antiarrhythmic drugs.
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Case Reports
Clinical and molecular characterization of patients with catecholaminergic polymorphic ventricular tachycardia.
Mutations in the cardiac ryanodine receptor gene (RyR2) underlie catecholaminergic polymorphic ventricular tachycardia (CPVT), an inherited arrhythmogenic disease occurring in the structurally intact heart. The proportion of patients with CPVT carrying RyR2 mutations is unknown, and the clinical features of RyR2-CPVT as compared with nongenotyped CPVT are undefined. ⋯ CPVT is a clinically and genetically heterogeneous disease manifesting beyond pediatric age with a spectrum of polymorphic arrhythmias. beta-Blockers reduce arrhythmias, but in 30% of patients an implantable defibrillator may be required. Genetic analysis identifies two groups of patients: Patients with nongenotyped CPVT are predominantly women and become symptomatic later in life; patients with RyR2 CPVT become symptomatic earlier, and men are at higher risk of cardiac events. These data provide a rationale for prompt evaluation and treatment of young men with RyR2 mutations.
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Meta Analysis
Interventions on prevention of postoperative atrial fibrillation in patients undergoing heart surgery: a meta-analysis.
Postoperative atrial fibrillation (AF) is a common complication of cardiac surgery and has been associated with increased incidence of other complications and increased hospital length of stay (LOS). Prevention of AF is a reasonable clinical goal, and, consequently, many randomized trials have evaluated the effectiveness of pharmacological and nonpharmacological interventions for prevention of AF. To better understand the role of various prophylactic therapies against postoperative AF, a systematic review of evidence from randomized trials was performed. ⋯ Beta-blockers, sotalol, and amiodarone all reduce risk of postoperative AF with no marked difference between them. There is evidence that use of these drugs will reduce LOS. Biatrial pacing is a promising new treatment opportunity. There was no evidence that reducing postoperative AF reduces stroke; however, data on stroke are incomplete.
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Mechanical assistance of the failing left ventricle (LV) can lead to functional recovery after a period of unloading, including restoration of beta-adrenergic receptor (betaAR) inotropic reserve. We tested whether prolonged LV unloading of failing rabbit hearts by use of a heterotopic transplantation technique could lead to recovery and whether adenoviral gene transfer of a beta2AR transgene (Adv-beta2AR) could alter this process. ⋯ Heterotopic transplantation in the rabbit does allow recovery of the failing heart, and beta2AR overexpression acutely enhances this functional improvement. Accordingly, genetic manipulation of betaAR signaling may represent a novel molecular adjunct to mechanical assistance to facilitate functional myocardial recovery.