Thermogenic supplement use does not alter characteristics of sudden death in the young.

BACKGROUND: To evaluate supplement use, most notably ephedra, which has been temporally associated with sudden death. Animal models suggest increased myocardial irritability may predispose to primary arrhythmic death. METHODS: Clinical, pathological, and investigative records from the Office of the Armed Forces Medical Examiner's Cardiovascular Death Registry were reviewed. Forty-eight cases of those with known supplement use were compared to 144 age-, gender-, and socioeconomic-matched controls in a 1:3 case:control manner. RESULTS: Of the 48 sudden deaths temporally associated with supplement use, the mean age was 34.2 ± 10.0 years and predominantly male (n = 44, 91.7%). The underlying cause of death was fatal atherosclerotic coronary disease in 18 (37.5%), sudden unexplained death in 16 (33.3%), and hypertrophic cardiomyopathy in six (12.5%). Compared with controls, there were no statistically significant differences in adjudicated cause of death. On autopsy, there were no differences in cardiac mass, ventricular wall thickness, or presence of atherosclerosis in those known to be taking identified supplements compared to a control population. In the subject ≥35 years, and known to be taking supplements, there was a significant increase in causality of death as due to sudden unexplained death (relative risk = 5.1 [95% confidence interval, 1.4-18.7]). CONCLUSIONS: Active surveillance of mortality in an autopsy-derived series of young adults finds atherosclerotic coronary disease and idiopathic sudden death are common etiologies of death when taking supplements, but no cardiac structural or histologic mechanism to suggest different pathologic process than a matched control population.

Sudden death in young adults: an autopsy-based series of a population undergoing active surveillance.

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 < 0.0001). Sudden death was attributed to a cardiac condition in 715 (79.3%) and was unexplained in 187 (20.7%). The incidence of sudden unexplained death (SUD) was 1.2 per 100,000 person-years for persons <35 years of age, and 2.0 per 100,000 person-years for those ≥ 35 years of age (p < 0.001). The incidence of fatal atherosclerotic coronary artery disease was 0.7 per 100,000 person-years for those <35 years of age, and 13.7 per 100,000 person-years for those ≥ 35 years of age (p < 0.001). 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 <35 years of age, with an emphasis on atherosclerotic coronary disease in those ≥ 35 years of age.

A tailored approach to catheter ablation of paroxysmal atrial fibrillation.

BACKGROUND: Because the genesis of atrial fibrillation (AF) is multifactorial and variable, an ablation strategy that involves pulmonary vein isolation and/or a particular set of ablation lines may not be equally effective or efficient in all patients with AF. A tailored strategy that targets initiators and drivers of AF is a possible alternative to a standardized lesion set. METHODS AND RESULTS: Catheter ablation was performed in 153 consecutive patients (mean age, 56+/-11 years) with symptomatic paroxysmal AF with the use of an 8-mm tip radiofrequency ablation catheter. The esophagus was visualized with barium. The pulmonary veins and left atrium were mapped during spontaneous or induced AF. Arrhythmogenic pulmonary veins were isolated or encircled. If AF was still present or inducible, complex electrograms in the left atrium, coronary sinus, and superior vena cava were targeted for ablation. The end point of ablation was absence of frequent atrial ectopy and spontaneous AF during isoproterenol infusion and noninducibility of AF. Routine energy applications near the esophagus were avoided. During follow-up, left atrial flutter developed in 19% of patients and was still present in 10% at >12 weeks of follow-up. A repeat ablation procedure was performed in 18% of patients. During a mean follow-up of 11+/-4 months, 77% of patients were free from AF and/or atrial flutter without antiarrhythmic drug therapy. Pericardial tamponade or transient neurological events occurred in 2% of procedures. CONCLUSIONS: A tailored ablation strategy that only targets triggers and drivers of AF is feasible and eliminates paroxysmal AF in approximately 80% of patients.