Results:

A total of 820 sports-related SDs occurred during the 5-year study period, yielding an estimated incidence of 4.6 per million population per year. The incidence was much higher in males (32.8/million/year) than females (1.9/million/year). The mean age at the time of SD was 46 years. SD occurred in a public sports facility in 52% of cases, and 99.8% of these were witnessed. Eighty-three percent of SDs that occurred outside a sports facility were witnessed. Bystander cardiopulmonary resuscitation (CPR) was performed in 31% of cases. Survival to hospital admission was 30.8%, and survival to hospital discharge was 15.7%. Independent predictors of survival to hospital discharge were bystander CPR (odds ratio [OR], 3.7), time to start of CPR (OR, 1.3), and the initial use of a defibrillator (OR, 3.7). A cause of SD was identified in 25% of cases. The most common etiology was coronary artery disease (75%). Other etiologies (each <5%) included hypertrophic cardiomyopathy, dilated cardiomyopathy, right ventricular dysplasia, Wolff-Parkinson-White syndrome, and commotio cordis.