What is commotio cordis?

Although thought to be rare, sudden deaths caused by nonpenetrating chest wall impact in the absence of structural injury to the ribs, sternum, and heart (commotio cordis) are reported with increasing frequency. This phenomenon is described in individuals when they are struck by relatively innocent blows to the chest wall. Young male athletes aged 5 to 18 years are particularly at risk for this catastrophe. It has been described after blows to the chest from baseballs, softballs, hockey pucks, and other objects. Death is usually instantaneous, and successful resuscitation is uncommon. A recently reported experimental model provides clues to the mechanisms and inferences for the prevention and treatment of this devastating condition. This swine model shows that a) ventricular fibrillation results from low-energy chest wall impacts during a vulnerable period of repolarization, b) the risk of this event can be decreased with softer-than-standard baseballs, and c) prompt defibrillation is crucial for resuscitation to be successful.