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.