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Objectives This study sought to evaluate the safety and effectiveness of catheter ablation of persistent atrial fibrillation (PsAF) using a porous tip contact force–sensing catheter. Backg...

Objectives The purpose of this study was to define the incidence and characterization of cardiovascular cause of sudden death in the young. Background The epidemiology of sudden cardiac death (SCD) in young adults is based on small studies and uncontrolled observations. Identifying causes of sudden death in this population is important for guiding approaches to prevention. Methods We performed a retrospective cohort study using demographic and autopsy data from the Department of Defense Cardiovascular Death Registry over a 10-year period comprising 15.2 million person-years of active surveillance. Results We reviewed all nontraumatic sudden deaths in persons 18 years of age and over. We identified 902 subjects in whom the adjudicated cause of death was of potential cardiac etiology, with a mean age of 38 ± 11 years. The mortality rate for SCD per 100,000 person-years for the study period was 6.7 for males and 1.4 for females (p Conclusions Prevention of sudden death in the young adult should focus on evaluation for causes known to be associated with SUD (e.g., primary arrhythmia) among persons

Background Healthy women have longer QT intervals and more drug-induced proarrhythmia compared to men, yet those given implantable cardioverter-difibrillators (ICDs) for ischemic cardiomyopathy have fewer episodes of ventricular tachycardia/ventricular fibrillation (VT/VF) than men. The role of repolarization duration and stability in arrhythmogenesis in men and women with structural heart disease has not been explored. Objectives The purpose of this study was to analyze repolarization differences between men and women and their relation to the risk of VT/VF. Methods Multicenter Automatic Defibrillator Trial II study patients underwent 10-minute, resting digitized recordings at study entry. QT and heart rate were measured for each beat with a semiautomated method. QT variance was normalized for mean QT (QTVN) or for heart rate variance (QTVI). Spectral analysis of heart rate and QT time series was performed; coherence was indexed to quantify consistency of heart rate and QT power spectra. The incidence of VT/VF was determined by ICD interrogation. Results There were 805 usable recordings (142 females); 463 received ICDs (86 females). There was no gender difference in mean or median QT, QTc, or heart rate. QTVN and QTVI were slightly (but significantly) higher, and the mean coherence was lower in women. In a Cox multivariate analysis, increased QTVN or QTVI (top quartile) was associated with a significantly higher risk for VT/VF in men (QTVN hazard ratio (HR) 2.2; confidence interval [CI] 1.4–3.4; P = .001; QTVI HR 1.9; CI 1.2–3.0; P = .006) but not in women, while reduced coherence (bottom quartile) predicted VT/VF in women (HR 3.3; CI 1.2–9.0; P = .021) but not in men. Conclusions In post–myocardial infarcation patients with depressed ejection fraction, both women and men manifest increased temporal variability in the QT interval. In men, QT variability by itself raised arrhythmic risk. In women, however, QT variability dissociated from HR variability (low coherence) appeared to be a uniquely significant predictor of arrhythmic events.

Chronotropic incompetence (CI) is the inability of heart rate response to meet metabolic demand. CI is associated with sinus node dysfunction, atrial fibrillation, or structural heart disease, and can lead to functional impairment. We report the case of a 34-year-old man with CI secondary to sinus node dysfunction who demonstrated significant improvement in functional capacity with rate-responsive pacing. Therapy for CI should be guided by the treatment of the underlying cause with consideration for rate-responsive pacing in symptomatic patients. The prognosis of CI is variable and dependent on underlying etiology.