Commotio cordis: a deadly consequence of chest trauma.

Commotio cordis is arrhythmia or sudden death from low-impact, blunt trauma to the chest without apparent heart injury. Ventricular fibrillation is the most common associated arrhythmia, and heart block, bundle branch block, and ST-segment elevation are also seen. Commotio cordis occurs most commonly in baseball but has also been reported in hockey, softball, and several other sports. Approximately two to four cases are reported each year, but the true incidence is uncertain. Survival is low, even when resuscitation is performed. Preventive measures include education of participants and coaches, chest protection, and softer baseballs. Other considerations include having external automatic defibrillators and trained personnel at youth sporting events.