Damar Hamlin's on-field collapse during a Monday Night Football game on January 2 was caused by commotio cordis, the Buffalo Bills safety told the media Tuesday.
"[Commotio cordis is] a direct blow at a specific point in your heartbeat that causes cardiac arrest," Hamlin said, adding that, about five to seven seconds after the blow, you collapse—which is what viewers saw during the football game.
Following his collapse on live TV, Hamlin was given medical attention for nearly 20 minutes—including nine minutes of CPR—before being taken to the University of Cincinnati Medical Center where he underwent further testing and treatment.
Hamlin made a swift recovery, and on January 9—just days after his on-field medical emergency—he was released from the hospital and sent back home to Buffalo.
In addition to revealing his exact diagnosis Tuesday, Hamlin also announced that he intends to return to the NFL for the upcoming season. "This event was life-changing," he said, "but it's not the end of my story."
Hamlin also said he intends to focus his efforts on helping to spread awareness about commotio cordis, particularly in youth sports. "Commotio cordis is the leading cause of death in youth athletes across all sports," Hamlin said. "So that's something that I will personally be taking a step in to make a change."
How Coverage of Damar Hamlin's Cardiac Arrest and CPR Could Go On to Save Countless Lives
What is Commotio Cordis?
Commotio cordis is a very rare cause of cardiac arrest, and is essentially just an “incredibly unlucky event,” Rebecca Stearns, PhD, chief operating officer of the Korey Stringer Institute and professor of kinesiology in the college of agriculture, health, and natural resources at the University of Connecticut, told Health.
Commotio cordis is, essentially, a cardiac arrest due to trauma to the heart at a very specific point in a persons' cardiac cycle, according to Eric Adler, MD, professor of medicine and director of the heart failure program at University of California San Diego Health.
“This particular amount of force, combined with the timing of where the heart is in its electrical cycle, or cardiac rhythm, causes a disruption in the electrical pathway,” Stearns explained. “When you disrupt that electrical pathway and that rhythm, it becomes discoordinated. And so that causes fibrillation in the heart—basically discoordinated contractions of the heart that don't allow [for] proper diffusion and processing of the blood.”
When the blood isn’t being pumped from the heart out to the rest of the body in an efficient manner—or if it just stops pumping in general—that’s termed a cardiac arrest. When this happens, a person’s heart won’t be able to get blood to vital organs like the brain and lungs, and the situation can turn fatal in a matter of minutes.1
Cardiac arrest is responsible for 300,000 to 450,000 deaths in the U.S. each year, and nine out of ten people who have a cardiac arrest outside of a hospital setting die.2 Without prompt use of an automated external defibrillator (AED)—which sends a shock to the heart to help restart it or make the heartbeat normal again—a person can die very quickly. And the more time that passes, the worse the possible outcome—by one estimate, for every minute without CPR, the chance of survival for a person having a cardiac arrest goes down by 7 to 10 percent.3
Some cardiac arrests can be caused by heart disease or genetic heart issues, and people can be screened to find out if they’re at a higher risk.4 But commotio cordis can cause cardiac arrest in an otherwise healthy person.5 Researchers at this point don’t think there’s anything that might make a person more susceptible to commotio cordis—it’s just being in the wrong place at the wrong time.
“It's not going to be picked up on a pre-participation exam, which is typical—all athletes typically have to go through some sort of medical exam to participate. It's not going to come up on a genetic screening,” Stearns said. “So it really can happen to anyone.”
What Is CPR?
A Risk for Athletes
Research has shown that commotio cordis seems to affect young male athletes more frequently. There are a couple of potential explanations for this, Jordan Prutkin, MD, MHS, associate director of the center for sports cardiology at University of Washington Medicine, said.
“There are a lot more people who play high school sports, or even college sports versus professional sports,” Dr. Prutkin told Health. “So there's a lot more opportunities for this to happen in younger people.”
A second explanation is that younger people’s sternums—the long, flat bone in the center of the chest and above the heart—are not as rigid as adults’ typically are, Dr. Prutkin said. With a less protective chest wall, it might be easier for a blow to push on a child’s or teen’s heart and cause commotio cordis.
The condition is also a bit more common among people who do martial arts, or those who play sports with hard balls, such as hockey, lacrosse, or baseball, Stearns and Dr. Prutkin said. Out of the 128 commotio cordis cases tracked in one study, 46 happened during baseball or softball games, and 13 happened during ice hockey games.6
Though it’s most common among children, commotio cordis cases have been documented in other high-profile professional sporting events. In 1998, NHL star Chris Pronger had a cardiac arrest on the ice from commotio cordis after being hit in the chest by a puck, though he was only unconscious for about 20 seconds.7
“It doesn’t happen very frequently in football. It doesn't happen very frequently at all,” Dr. Adler added.
There have been other high profile cases of emergencies during sporting events, though none seem to have been caused by commotio cordis. Danish soccer player Christian Eriksen had a cardiac arrest during a game in the summer of 2021, and like Hamlin, survived the incident.8 In football, there has been just one death on the field—Chuck Hughes died of a heart attack during a game in 1971, though he had undiagnosed heart disease.9 Reggie Lewis and Hank Gathers died of cardiac arrests while playing basketball, though both had a genetic disorder called hypertrophic cardiomyopathy.10 Commotio cordis in football seems to be a first.
However, these other high profile instances of heart attacks and cardiac arrests likely explain why the NFL was as prepared as they were for the situation.
“There was a well trained staff. I mean the fact that they had the ability to defibrillate an [AED] within even that period of time, is amazing—would not have been the case 10 years ago,” Dr. Adler said. “It's only because we've had this happen before, and sports medicine has evolved and cardiology has evolved, that we know to have this thing.”
Heart Attacks: Is There an Average Age That Increases Your Odds?
Being Prepared for Emergency Situations is Key
Commotio cordis, because it’s being in the wrong place at the wrong time, is likely pretty challenging to prevent completely, Stearns said. But small things like adding more padding and making sure athletes have proper equipment could potentially help this situation from happening in the future, Dr. Adler added.
Beyond these small changes, however, Hamlin’s case probably isn’t the canary in a coal mine exposing cardiac dangers for NFL players, Dr. Adler explained. A “one in a million” case like this probably isn’t grounds to change the way the NFL operates, he said.
NFL players already undergo a test called an electrocardiogram (ECG) while they’re being scouted.11 This test can determine if a person has any heart issues or abnormalities that might make them more susceptible to cardiac arrests, Dr. Prutkin said.
Plus, NFL games are staffed with medical professionals who can administer high quality CPR and an AED when necessary. Hamlin’s remarkable recovery is proof of how important this quick care really is.
“You could clearly see they had an emergency action [plan] in place, like they got on the field immediately, they had the ambulance right there, they reportedly restored his heart on the field,” Stearns said. “You can see all these mechanisms in place, to be prepared and to go into action when something happens.”
But though the NFL seemed prepared, the same isn’t always the case for sports more generally. Cardiac arrests that are not freak accidents—ones caused by heart disease or genetic conditions, for example—can be spotted using an ECG test, Dr. Prutkin said, but they’re not always used routinely before athletes start competing.
“[An ECG] has a pretty good accuracy for trying to determine if there's any underlying heart disease which might put someone at higher risk for cardiac arrest. And if an abnormality is found, it doesn't mean that someone couldn't play. It's really trying to do our best to do a full evaluation and then figure out what are the ways that we can allow it to happen safely,” he said.
The debate about testing all athletes with an ECG is still ongoing, Dr. Adler said. Testing every athlete for heart issues may not be completely realistic, and it may be a matter of finding better or more efficient ways to test.
Regardless, “If you can identify people with abnormal hearts before they do sport, that's the best way of preventing them from dying on the field,” Dr. Adler said.
Not only is cardiac arrest prevention not always up to par in non-professional settings, but quick treatment for these cases is also often lacking. There are initiatives to make AEDs accessible and have CPR-trained personnel at lower level sporting events, but that doesn’t always happen, Stearns explained.
“I look down the line of college and even further down into the high school level, and [I wonder] if our high school athletes are getting that same access to really critical care items that could save their life. We know that about 30% of high schools don't have any medical professional hired or on site for them,” Stearns said. “Clearly it can work. But are we providing that same basic care to other athletes as well?"
In addition to Hamlin’s case sparking a conversation about the importance of CPR, it’s also an opportunity to increase awareness about commotio cordis and the ways that it can be effectively treated, whether someone’s playing in the NFL or in Little League.
And despite how scary Hamlin's cardiac arrest was, the small possibility of a person developing commotio cordis should not be reason enough to ditch sports altogether, Dr. Prutkin said, especially when we have effective treatment plans in place.
“This is really rare. We know there's a lot of benefits to playing sports in terms of both physical health and mental health,” he said. “I would really encourage everyone to play sports, if that's a choice that they want to make and something that they enjoy.”