No potential confl ict of interest declared. DOI: 10.1177/1941738108330972 © 2009 American Orthopaedic Society for Sports Medicine

Content: Commotio cordis is blunt, nonpenetrating trauma to the chest resulting in irregular heart rhythm and often leading to sudden death. This article presents the epidemiology, variables leading to commotio cordis, theories on predisposing factors, diagnosis, treatment, treatment outcomes, and return-to-play recommendations. Evidence Acquisition: A PubMed (MEDLINE) search for commotio cordis was conducted on July 1, 2008, and it yielded 106 results, of which 26 were used for this review, including experimental models, simulation studies, case analysis studies, case reports, general recommendation, review articles, and editorials. Results: There are more than 190 reported cases of commotio cordis in the United States. Forty-seven percent of reported cases occurred during athletic participation. Commotio cordis is the second-most common cause of sudden cardiac death in athletes. Occurrence of commotio cordis is related to time of impact during the cardiac cycle, direct impact over the heart, the hardness and speed of the projectile, and the ineffectiveness of chest barriers. As a result, the US Consumer Product Safety Commission recommends that softer “safety ” baseballs be used for youth baseball. Resuscitation using defi brillation was effective in only 15 % of cases. Resuscitation within 3 minutes resulted in a survival rate of 25 % (17 of 68 cases). Survival drops to 3 % when resuscitation is delayed beyond 3 minutes. Survival of commotio cordis has risen from 10 % to 15 % since 2001. Reduced ventricular ejection fraction has been identifi ed in some commotio cordis survivors