Overview of sudden cardiac death in young athletes

Sport Related Sudden Death: The Importance of Primary and Secondary Prevention

Sports are a double-edged sword. On the one hand, cardiovascular benefits from sports activity are well-known, and on the other hand, sports may increase the risk of sudden cardiac death (SCD) in subjects with known or unknown cardiovascular diseases. SCD is rare but has a very strong emotional issue. There are many examples involving famous professional athletes, but this is only scratching the surface of a widespread phenomenon that also involves amateur athletes. The importance of safely performing physical activity appears clear in both professional and amateur athletes. In particular, the former undergo a pre-participation screening for SCD primary prevention with different recommendations in each country. On the other hand, a medical examination is not mandatory for non-professional athletes and, therefore, for people who practice sports as an amateur. Widespread distribution of automatic external defibrillators and people trained for cardiopulmonary resuscitation are necessary to promote secondary prevention of SCD. We briefly report a case series of athletes with aborted SCD during sports activity in order to underline and discuss in this review the previously highlighted issues.

Exercise, the athlete's heart, and sudden cardiac death

Physical activity is a potent therapy for both the prevention and treatment of cardiovascular disease. Exercise appears to most benefit people who are the least active. There is some evidence to suggest that a curvilinear relationship exists between exercise and survival, whereby beyond an optimal level of fitness, the principle of diminishing returns applies. Indeed, some go further in suggesting that there is evidence that extreme athletic training may be harmful in some individuals. The incidence of sudden cardiac death in athletes is greater than in matched, nonathletic counterparts, and this finding is driven by the provocation of an underlying cardiac abnormality by strenuous exertion. The task of detecting pathological myocardial substrate in athletes is made difficult by physiological adaptations to exercise that can mimic the appearance of cardiomyopathies and ion channelopathies in some individuals. This article details the clinical evaluation of the athlete with reference limits for cardiac physiological remodeling and discusses the diagnostic dilemmas that arise.

Impact of ethnicity on cardiac adaptation to exercise

The increasing globalization of sport has resulted in athletes from a wide range of ethnicities emerging onto the world stage. Fuelled by the untimely death of a number of young professional athletes, data generated from the parallel increase in preparticipation cardiovascular evaluation has indicated that ethnicity has a substantial influence on cardiac adaptation to exercise. From this perspective, the group most intensively studied comprises athletes of African or Afro-Caribbean ethnicity (black athletes), an ever-increasing number of whom are competing at the highest levels of sport and who often exhibit profound electrical and structural cardiac changes in response to exercise. Data on other ethnic cohorts are emerging, but remain incomplete. This Review describes our current knowledge on the impact of ethnicity on cardiac adaptation to exercise, starting with white athletes in whom the physiological electrical and structural changes--collectively termed the 'athlete's heart'--were first described. Discussion of the differences in the cardiac changes between ethnicities, with a focus on black athletes, and of the challenges that these variations can produce for the evaluating physician is also provided. The impact of ethnically mediated changes on preparticipation cardiovascular evaluation is highlighted, particularly with respect to false positive results, and potential genetic mechanisms underlying racial differences in cardiac adaptation to exercise are described.