What is commotio cordis?

What is commotio cordis?

Sometimes a player drops down dead after being accidentally hit by a ball or another player. This situation which can occur in any contact sports is known as commotio cordis. The sudden hit on the chest causes the heart to stop in ventricular fibrillation. Ventricular fibrillation is a very fast irregular electrical activity of the lower chambers which prevents proper contraction of the heart. The intensity of the blow is not sufficient to cause any damage to the chest wall. No structural damage is noted in the heart as well. If there is a contusion (bruising) of the heart, it will be called contusio cordis. Contusio cordis is associated with damage to the chest wall as well.

The rapid rise in left ventricular pressure following the impact possibly results in mechanical activation of the electrical system of the heart producing the lethal heart rhythm abnormality. Left ventricle is the lower muscular chamber of the heart which pumps oxygenated blood to the whole body. Generally commotio cordis is caused by impact by a ball with a dense solid core like baseball. Balls with non-solid core tend to collapse on contact and absorb most of the impact energy so that commotio cordis is quite rare with impact by an air filled soccer ball.

Commotio cordis is more likely to occur in younger individuals, possibly because of greater transmission of the impact energy by a compliant chest wall. 95% of cases occur in adolescent males, with an average age of 14 years.

In an experimental study using baseballs, the minimum speed of the baseball for causing ventricular fibrillation was between 40-48 km/h. Peak incidence was at impacts at 64 km/h. The likelihood of ventricular fibrillation decreased at velocities above 80 km/h. This agrees with the usual observation of commotio cordis in youth baseball with estimated speeds in the range of 48 to 80 km/h.

The development of better chest protectors and widespread use of automated external defibrillators (AED) in the playground may help prevent such deaths. AED is a device which can be operated by minimally trained persons, and used to treat ventricular fibrillation on the scene. When the electrode patches of the AED are applied to the chest, it gives audio prompts if a heart rhythm abnormality which can be treated by an electrical shock (shockable rhythm) is detected. If there is no shockable rhythm, the device asks for continuation of chest compressions and artificial breathing (CPR, cardiopulmonary resuscitation).

All those lucky ones who survive should be thoroughly tested for any heart disease which can predispose to heart rhythm abnormality. There is some information from animal experiments which suggests individual susceptibility to commotio cordis. It will be prudent to avoid sports which involve chest wall impacts after the event. Maturation of chest wall with age can reduce the risk of recurrence later.