Commotio cordis: an underappreciated cause of sudden death in athletes.

Over the last few years, the recognised cardiovascular risks of sporting activities have been extended to include cardiac arrest resulting from low-energy precordial chest impact produced by projectiles (e.g. baseball) or bodily contact, in the young, healthy and active athlete [also known as commotio cordis (CC)]. However, case reports of CC in European medical literature can be traced back for at least 130 years. CC accounts for a small, but important, subset of sudden death during sporting activities. It is a devastating electrophysiological event in the young athlete, and one which has generated considerable concern, both in the medical profession as well as in the public. The mechanism of sudden death appears to be caused by ventricular fibrillation, which occurs when the chest impact is delivered within a narrow, electrically vulnerable portion of the cardiac cycle, that is, during repolarisation, just before the peak of the T wave. Resuscitation of these victims is possible with prompt cardiopulmonary resuscitation and defibrillation. Preventive measures, such as the use of age-appropriate safety baseballs and suitably designed chest wall protection, may reduce the risk of sudden death and, thus, make the athletic field a safer place for young athletes.