A Blow To the Chest That Disrupts Heart Rhythm Can Kill You

Commotio cordis — Latin for “disruption of the heart” — is a rare interference of heart rhythm that occurs as the result of a blow to the area directly over the heart at a critical instant during the cycle of the heartbeat. If not treated within 3 minutes, it’s 97% fatal. This sudden rise in pressure in the chest area leads to the disruption of normal heart electrical activity, followed by a complete disorganization of the heart’s pumping function, and eventually cardiac arrest. There are fewer than 20 cases per year in the United States, often occurring when a baseball strikes a player in the chest. It can occur only upon impact within a narrow window of about 40 milliseconds in the cardiac electrical cycle, which explains why it’s so rare. If CPR combined with the use of a defibrillator is employed within 3 minutes of impact, survival can be as high as 58%. This is one of the reasons organizations have pushed for chest protectors, especially in sports involving adolescents, who are more prone to this injury because of their under-developed thorax — the area of the body between the neck and the abdomen. Aside from sports, commotio cordis can also occur in frontal collisions of motor vehicles, with the impact of the steering wheel against the thorax, though this has decreased substantially with the use of seat belts and air bags.