Commotio Cordis: A Cardiologist Explains Why a 24 Year Old Pro Football Player Had a Cardiac Arrest on National TV

By Nancy Kennedy

On the evening of January 2, 2023, millions of Americans were enjoying watching the Buffalo Bills and Cincinnati Bengals do battle on Monday Night Football. But the game came to an unexpected halt when Buffalo safety Damar Hamlin, 24, suddenly collapsed on the field with no heartbeat, following a routine tackle.

As fans, fellow athletes and a national audience watched in stunned silence, a team of physicians, trainers and paramedics descended on Hamlin, rendering immediate resuscitative care including CPR. Hamlin’s heart had gone into an arrhythmia – an abnormal, often lethal heartbeat rhythm – known as ventricular fibrillation, which leaves the heart essentially quivering and failing to pump blood to the brain and vital organs. The responders used a defibrillator to try to shock his heart back into a normal rhythm. The unconscious Hamlin, who grew up in McKees Rocks and attended Central Catholic High School and Pitt, was emergently transported to the University Of Cincinnati Medical Center to an intensive care unit where he is recovering and continues to receive state-of-the-art cardiac critical care.

What happened? Why did a healthy and perfectly fit 24-year old professional athlete suddenly go into cardiac arrest during a game?

Alan Bramowitz, M.D., a cardiologist with Jefferson Cardiology Associates, explains that the physicians managing Hamlin’s care immediately suspected that a process known as “Commotio Cordis” had occurred. “It appeared most likely that the football player suffered a cardiac arrest due to “commotio cordis” – an extremely rare condition in which direct, blunt chest trauma results in cardiac arrest from induction of potentially fatal abnormalities of the heart’s electrical system.”

Commotio Cordis, from the Latin meaning “disruption of the heart,” can be the result if the impact of the object happens at a precise, critical moment during the cycle of a heartbeat. Commotio cordis is not an injury or a medical condition, but a process. The chest is not penetrated and the heart is not damaged.

“Energy is transmitted from the chest wall to the heart muscle, during a very specific vulnerable period in the heart cycle – a period that lasts a mere 15-30 milliseconds and represents only 1% of the cardiac cycle. That’s why this is so very rare. Commotio cordis typically occurs in youth sports as it is suspected that narrow pliable walls of the chest facilitate this energy transmission. The mean age is 13. The National Commotio Cordis Registry reports that the majority of cases involve baseball and the majority of victims are young boys. Often, the chest blows are not particularly powerful or associated with trauma to the ribs or the heart itself,” Dr. Bramowitz says. “The heart is structurally normal.”

Commotio cordis has been known to occur in baseball, hockey, football, lacrosse, karate and other sports. Prompt defibrillation improves the prognosis. “Under the best circumstances, normal rhythm and circulation can be re-established after one shock with the defibrillator,” says Dr. Bramowitz. “There can be complications. During the resuscitation, there may be insufficient brain perfusion, which leads to concern about damage to the brain, liver and kidneys. The functioning of these organs has to be assessed.

“Certainly, the need for defibrillators at sporting events is well recognized. This event has spurred public interest in CPR training and in learning how to use a defibrillator. Published reports indicated 15% survival in 2005, but with more available public access defibrillators and public education about CPR, survival rates more recently have been published at 58%.”

Preventive actions have been taken in youth sports, including the use of a softer baseball as well as chest protectors for baseball catchers and hockey goalies. “The question of chest protection has been raised but there is currently no evidence of benefit from them,” Dr. Bramowitz says. “Simulated experiments with pigs failed to demonstrate that chest protectors were effective in preventing arrhythmias after blunt chest trauma. However, this will no doubt continue to be explored in a national effort to improve the safety of athletic competition.”

How to Use an Automated External Defibrillator

In the wake of Damar Hamlin’s cardiac arrest during an NFL game, there has been a surge of interest among the public to learn the correct procedures for cardiopulmonary resuscitation (CPR) and the use of an automated external defibrillator (AED), the device that shocks the heart and hopefully restores a normal heart rhythm.

In Pittsburgh, public access defibrillators are available in many places, including schools, restaurants, sports arenas, churches and theatres.

Performing bystander resuscitation within moments after cardiac arrest can greatly increase survival rates.

The Red Cross offers classes in both CPR and AED use, in many locations in the region. Visit redcross.org/take-a-class/aed

To learn more, visit callpushshock.org, a national collaborative based in Wexford that was founded for the purpose of empowering bystanders to perform CPR and use an AED when someone has experienced a sudden cardiac arrest.