What is it?
If a person is struck in the chest at a specific time in the heart rhythm cycle, the heart’s electrical signal can be interrupted, resulting in the heart stopping. This rare cause of the heart suddenly stopping is called “commotio cordis.” The blunt force that causes commotio cordis often comes from a hard object or ball hitting the chest, such as a baseball, a softball, or a hockey puck, but it can come from any type of blow. The average victim of commotio cordis is 14 years of age. Young people are at higher risk because the chest wall is less developed and transmits force more easily.

Symptoms
A person who suffers commotio cordis will collapse and be unresponsive following a blow to the chest. A pulse will not be felt and the person may not be breathing. Sometimes there will be jerking movements in the arms and legs, but this should not be confused with a seizure. Gasping breaths may also be seen, but this does not mean the person is breathing normally.

Treatment
Once the person is found to be unconscious, his or her heart must be assumed to have stopped and immediate treatment is needed. This involves calling 911, starting CPR (cardiopulmonary resuscitation) with chest compressions, and retrieving the nearest AED (automated external defibrillator). An electric shock from an AED should be delivered as soon as possible. CPR should not delay this. Emergency support should be continued until the ambulance arrives and medics take over.

Injury Prevention
Use of age-appropriate, soft baseballs up to age 13 is recommended. Chest protectors have not yet been shown to be effective in reducing risk. The most important strategy is to prepare for sudden cardiac arrest by training coaches and staff in recognizing commotio cordis and sudden cardiac arrest. They must also be trained how to do CPR and use an AED. Additionally, an AED should be accessible at any organized sporting event within a minute of the playing venue so that a shock can be given within 3 minutes of an athlete’s collapse.

Return to Play
A sports medicine provider may try to rule out other causes of sudden cardiac arrest by evaluating a person’s heart with an electrocardiogram (EKG), an echocardiogram (ultrasound evaluation of the heart), and extended heart rhythm monitoring. If no underlying heart problems are found and there is no other injury resulting from the sudden cardiac arrest (stopping of the heart) or blunt trauma, there are typically no restrictions for returning to play in competitive sports.

AMSSM Member Authors
Brett Toresdahl, MD and Chad Carlson, MD

References
Link MS. Commotio cordis: ventricular fibrillation triggered by chest impact-induced abnormalities in repolarization. Circ Arrhythm Electrophysiol. 2012 Apr;5(2):425-32.

Maron BJ. Commotio cordis. N Engl J Med. 2010 Mar 11.