How to recognize and prevent Commotio Cordis
Josh Bloom, MD, MPH
Commotio cordis is a condition in which blunt trauma to the chest triggers sudden cardiac arrest (heart stops beating). It is caused most frequently by small spherical projectiles (such as a baseball, lacrosse ball, hockey puck) and occurs most frequently in young males. Although this condition is quite rare, commotio cordis is one of the more common causes of sudden cardiac arrest in young athletes, particularly baseball players.
Commotio cordis is defined as abrupt cardiac arrest caused by blunt trauma to the chest wall which causes ventricular fibrillation (a lethal cardiac rhythm). This lethal cardiac rhythm is triggered by direct trauma to a particular area of the heart (the cardiac silhouette) at a very specific time during the heartbeat. Experimental models show commotio cordis is typically caused by harder, smaller spherical objects such as a ball and seems to be more common at velocities up to 40 mph, but less common at velocities significantly greater or significantly less than 40 mph. While the exact number of cases of commotio cordis is unknown, in the mid-1990s the National Commotio Cordis Registry was established in the United States and now over 200 confirmed cases have been studied and documented providing a relative wealth of data on this rare condition. These data show this condition typically occurs in young people (mean age 15), 95% cases are in males, and 75% occur during competitive sports, most often those sports that involve blunt projectiles (baseball, lacrosse, hockey).
Commotio cordis should be immediately considered in any athlete who collapses after being struck in the chest. If the athlete is found to be unresponsive, immediately activate EMS, initiate your Emergency Action Plan and start CPR if the athlete is not breathing and/or pulseless. While there were no reported survivors in the first 25 cases recorded in the National Commotio Cordis Registry, survival has increased to 58% for cases reported between 2006-2012. This is likely due to early recognition, rapid activation of Emergency Medical Services, particularly early CPR and defibrillation. Many of these defibrillations were performed by bystanders using Automated External Defibrillators (AEDs).
Avoidance of chest trauma with hard, blunt objects is the foundation of prevention. This is, however, inherently difficult in baseball. Nonetheless, it is interesting and important to note that softer, less dense balls in younger age groups (for example, softer baseballs in youth leagues) have been shown to decrease the incidence of commotio cordis. In 2017, the National Operating Committee on Standards for Athletic Equipment (NOCSAE) established a new standard for the evaluation of chest wall protectors to prevent commotio cordis. However, commercially available chest protectors have NOT been shown to be effective in preventing commotio cordis in the laboratory setting or in the community. In fact, some of the commotio cordis victims were wearing protective equipment at the time of their injury.
Commotio cordis is a rare but life-threatening injury that can occur due to blunt chest trauma in baseball players. Recognition and rapid initiation of treatment including CPR and defibrillation are keys to survival of this injury. Accordingly, an operational, readily available AED is one of the most important pieces of equipment for any youth sports facility or league.
• Commotio cordis is sudden cardiac arrest caused when a blunt object strikes the chest triggering a potentially lethal heart rhythm.
• Once universally fatal, many young athletes now can survive Commotio Cordis if they are treated with rapid initiation CPR and defibrillation. An operational, readily available AED is a crucial piece of safety equipment for youth sports complexes and leagues.
• Commercial chest protection has not been shown to be effective in preventing commotio cordis.
• Commotio Cordis is most common in young athletes, particularly males.
• While Commotio Cordis can be caused by any blunt trauma to the chest, it is most commonly caused by relatively low velocity (<40 mph) blunt trauma from a cylindrical object such as baseball, hockey puck or lacrosse ball.
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Josh Bloom, MD, MPH, CAQSM is a partner physician at Carolina Family Practice & Sports Medicine. He is Team Physician for USA Baseball, Head Medical Physician for the Carolina Hurricanes (NHL), Team Physician of Apex Friendship (NC) High School, and Medical Director of the Carolina Sports Concussion Clinic. Dr. Bloom serves on the USA Baseball Medical & Safety Committee, the NHL Research Subcommittee, the NHL Concussion Return to Play Subcommittee, and the North Carolina High School Athletics Association Sports Medicine Advisory Board.