Sudden Cardiac Death in Athletes: Incidence, Causes and Prevention Strategies

Abstract

Sudden cardiac death (SCD) is the leading medical cause of death in athletes. Current reports on incidence are limited by methodological issues including difficulty with case identification and defining at-risk populations. There are, however, clearly higher risk groups including males, Afro-American/Caribbean athletes and certain sports such as men’s basketball, men’s football (soccer) and American football. In a young, athletic population, the overall risk of SCD is about 1 in 50,000 athlete-years (AY), although in high risk groups it may be as high as 1 in 5000 AY. The causes of SCD are also age-dependent with athletes <25 years of age dying most often from congenital, structural or electrical causes and those >25 dying from coronary artery disease. Structural causes of death include hypertrophic cardiomyopathy, arrhythmogenic cardiomyopathy, dilated cardiomyopathy, coronary artery anomalies, and aortic rupture. Electrical causes of SCD include Long QT Syndrome, Brugada Syndrome, Catecholaminergic Polymorphic Ventricular Tachycardia, and Wolff-Parkinson-White Syndrome. Other causes of SCD include myocarditis. A ‘suspected cardiac death’ may be observed in those with a structurally and histologically normal heart; this is often referred as sudden arrhythmic death syndrome (SADS) or sudden unexplained death (SUD). Primary prevention includes screening for conditions that predispose to SCD and in young athletes via history and physical examination, with or without a 12-lead electrocardiogram (ECG). ECG is the most accurate way to detect athletes with occult cardiovascular conditions, however, there is debate over the practicality of implementation on a large scale and the benefits of early diagnosis. Development and practice of an emergency action plan (EAP) is critical for secondary prevention with an aim of defibrillation in less than 3 min after collapse.