Sometimes a player drops down dead after being accidentally hit by a ball or another player. What do you call this?

Sometimes a player drops down dead after being accidentally hit by a ball or another player. What do you call this?

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. The intensity of the blow is not sufficient to cause any damage to the overlying structures. No structural damage is noted in the heart as well. The rapid rise in left ventricular pressure following the impact possibly results in activation of ion-channels by electro-mechanical coupling. The development of better chest protectors and widespread use of automatic external defibrillators in the playground may help prevent such deaths.