Circulation. Arrhythmia and electrophysiology
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Circ Arrhythm Electrophysiol · Oct 2012
Multicenter StudyEpinephrine infusion in the evaluation of unexplained cardiac arrest and familial sudden death: from the cardiac arrest survivors with preserved Ejection Fraction Registry.
Epinephrine infusion may unmask latent genetic conditions associated with cardiac arrest, including long-QT syndrome and catecholaminergic polymorphic ventricular tachycardia (VT). ⋯ Epinephrine challenge provoked abnormalities in a substantial proportion of patients, most commonly a prolonged QT interval. Exercise and genetic testing replicated the diagnosis suggested by the epinephrine response in a small proportion of patients. Epinephrine infusion combined with exercise testing and targeted genetic testing is recommended in the workup of suspected familial sudden death syndromes. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT00292032.
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Circ Arrhythm Electrophysiol · Oct 2012
Multicenter StudyShock efficacy of subcutaneous implantable cardioverter-defibrillator for prevention of sudden cardiac death: initial multicenter experience.
Recently, subcutaneous implantable cardioverter-defibrillator (S-ICD) has become available. The aim of our study was to assess the efficacy of S-ICD in a clinical setting. ⋯ Ineffective shock delivery may occur in patients with S-ICD, even after successful intraoperative testing. Multicenter trials are required with close monitoring of safety and efficacy end points to identify patients who may be at risk for shock failure.
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Circ Arrhythm Electrophysiol · Aug 2012
Randomized Controlled Trial Multicenter StudyRelevance of electrical remodeling in human atrial fibrillation: results of the Asymptomatic Atrial Fibrillation and Stroke Evaluation in Pacemaker Patients and the Atrial Fibrillation Reduction Atrial Pacing Trial mechanisms of atrial fibrillation study.
In animal models of atrial fibrillation (AF), changes in atrial electrophysiological properties are associated with the development of AF. Their relevance to human AF is unclear. ⋯ Prolonged P-wave duration, but not differences in atrial effective refractory periods, was associated with the development of atrial tachyarrhythmias in pacemaker patients.
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Circ Arrhythm Electrophysiol · Aug 2012
Multicenter StudyPredictive value of beat-to-beat QT variability index across the continuum of left ventricular dysfunction: competing risks of noncardiac or cardiovascular death and sudden or nonsudden cardiac death.
The goal of the present study was to determine the predictive value of beat-to-beat QT variability in heart failure patients across the continuum of left ventricular dysfunction. ⋯ Increased QTVI because of depressed heart rate variability predicts cardiovascular mortality and non-SCD but neither SCD nor extracardiac mortality in heart failure across the continuum of left ventricular dysfunction. Abnormally augmented QTVI separates 97.5% of healthy individuals from heart failure patients at risk.
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Circ Arrhythm Electrophysiol · Aug 2012
Multicenter StudyFamilial evaluation in catecholaminergic polymorphic ventricular tachycardia: disease penetrance and expression in cardiac ryanodine receptor mutation-carrying relatives.
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited arrhythmia syndrome associated with mutations in the cardiac ryanodine receptor gene (Ryr2) in the majority of patients. Previous studies of CPVT patients mainly involved probands, so current insight into disease penetrance, expression, genotype-phenotype correlations, and arrhythmic event rates in relatives carrying the Ryr2 mutation is limited. ⋯ Relatives carrying an Ryr2 mutation show a marked phenotypic diversity. The vast majority do not have signs of supraventricular disease manifestations. Mutation location may be associated with severity of the phenotype. The arrhythmic event rate during follow-up was low.