Largely unrecognized for years, commotio cordis is an event where a blunt, non-penetrating and innocent-appearing accidental hit to the chest causes abnormal heart rhythms and, many times, sudden death. Commotio cordis occurs most often in children, adolescents and young adults during recreational and competitive sports.
When a commotio cordis event occurs, cardiovascular collapse is generally immediate; however, 20 percent of individuals do remain active for a short period of time before collapsing. An example of this would be a pitcher who is struck in the chest by a line drive ball but is able to gather the ball and throw a runner out before collapsing to the ground.
In the March 11, 2010 issue of New England Journal of Medicine (NEJM), N.A. Mark Estes III, MD, Director, New England Cardiac Arrhythmia Center at Tufts Medical Center, [LINK to N.A. Mark Estes III MD profile] and Barry J. Maron, MD, Director, Hypertrophic Cardiomyopathy Center of the Minneapolis Heart Institute Foundation, published an article titled “Commotio Cordis,” The article focused on potential causes and the most effective ways to prevent commotio cordis now and in the future.
A mysterious phenomenon explained
According to the NEJM article, recent experimental studies indicate that there are particular factors that cause commotio cordis. The first two determinants are the location and timing of the blow; the hit to the chest must occur directly over the heart and during a narrow and particular window of the cardiac cycle when the heart is electrically vulnerable for commotio cordis to occur. Other factors include the type of projectile and its size, shape and hardness.
The incidence of commotio cordis is primarily in boys who participate in sports activities such as baseball, ice hockey, football or lacrosse – activities in which participants could receive a blow to the chest delivered by a ball or puck used in the game. Although 75 percent of commotio cordis are sports related, the additional 25 percent occur during other activities, including being kicked in the chest by an animal, such as a horse, or being struck in the chest accidentally by an object not associated with organized sports.
Although usually fatal, survival rates have increased from 15 percent to 35 percent in the past decade. This higher survival rate is likely due to greater public awareness of commotio cordis, increased access to Automatic External Defibrillators (AEDs), and earlier activation of the chain of survival (911 call, and initiation of CPR, defibrillation and advanced life support measures).
Strategies that can protect athletes
Moving forward, improved coaching techniques, such as teaching baseball players how to turn away from pitches or hockey players how to avoid blocking shots with their chest, would continue to decrease the number of commotio cordis events. Development of improved chest equipment would better protect players from dangerous impacts as well.
The article also notes that a public health strategy to make AEDs more widely available would help prevent death from commotio cordis. These life-saving devices could give victims of commotio cordis a chance to survive by successfully restoring their heart rhythm. As Estes and Maron conclude, “Further efforts are needed to prevent these largely avoidable deaths by providing more education, better-designed athletic equipment and wider access to AEDs at organized athletic events. These strategies should result in a safer sports environment for our youth.”
To refer a patient or schedule an appointment with Dr. Estes, please call 617-636-6156 or visit the CardioVascular Center webpage.