Monday, June 6, 2011
Standing at the plate, kids dream of playing in the major leagues. Parents sit in the stands wishing for success and hoping that nobody gets hurt. Dreams turned into nightmares this weekend in Winslow, Arizona, when a 13 year old boy was hit in the chest by a baseball, collapsed and died. Stuff like this isn’t supposed to happen. Norman Rockwell scenes of Americana are not supposed to be replaced by the horror of Norman Bates and yet it is difficult to understand why people can die because of bad luck.
Commotio cordis describes an injury where blunt force to the center of the chest causes disruption of the normal electrical conduction system of the heart. It is a rare event with 15-20 cases reported in the United State every year. Most often, it is teenage boys who are killed in an organized sport when they have been hit by a baseball or hockey puck, but any blow to the chest can cause sudden death. There has to be a coming together of many events for the electrical short circuit to occur. There needs to be enough force applied at just the right angle to the chest wall at just the precise millisecond in the normal cycle of the heartbeat to cause the heart to stop beating.
The heart is a two stage electrical pump. Specialized cells in the atrium or upper chamber of the heart generate an electrical impulse that is conducted through specialized fibers that allow all the muscles cells to squeeze at the same time, generating a heartbeat and pumping blood to the body. If the electrical activity becomes chaotic, heart muscle lacks that coordination and it doesn’t squeeze, instead it jiggles or fibrillates. When atrial fibrillation involving the upper chambers of the heart occurs, the lower chambers, the ventricles can continue to work and the heat functions and beats. However, sudden death occurs in ventricular fibrillation. No heart beat is generated, blood doesn’t flow and the body dies immediately.
Getting hit in the chest is a common injury but commotio cordis resulting in ventricular fibrillation occurs so rarely because the injury has to occur squarely over the heart within the split second (actually within 10 milliseconds) that that heart has squeezed and is starting to fill up getting ready for the next heartbeat. The injury does not damage or bruise the heart muscle but instead affects the electrical signal within the heart.
The treatment for ventricular fibrillation (VFib) is by using electricity to shock the heart into a regular rhythm. The presence and use of an Automatic External Defibrillator (AEDs) saves lives and the sooner it can be used to shock the patient, the better the chance that the patient can cheat sudden death. Lifesaving courses like the American Heart Association’s Basic Life Support has been rewritten to emphasize the use of AEDS. It is part of the first command when finding a collapsed victim: “You, call 9111, you get the AED”. While CPR can be a temporary bridge to circulate blood through the body, without a spontaneous heartbeat, the patient is dead.
AEDs are found in shopping malls, airports, schools and most places where people congregate but rarely are they found outside. The next political slogan should be that every family should have an AED in the trunk of their car; they cost less than a minivan’s entertainment system. Using an AED is relatively foolproof with a computerized voice giving step by step instructions. Ideally, everybody should learn CPR and learn how to use an AED.
Commotio cordis is a rare event but happens enough that it is routinely mentioned in medical textbooks. It is little comfort to the parents of the teen who died in Winslow or to the boy who threw the pitch. Dreams can turn into nightmares because of 10 milliseconds. While defibrillation can’t be guaranteed to work, it is the only hope for any patient with sudden death. All it takes is the commitment of a community to learn how to use a little technology.