On Jan. 2, 2023, the nation watched as Buffalo Bills safety Damar Hamlin, 24, went into cardiac arrest after making a tackle during a Monday Night Football game against the Cincinnati Bengals. With blood flow to his brain disrupted, Hamlin lost consciousness and collapsed on the field. His heartbeat was restored by medical personnel before he was transported to a Cincinnati hospital, later transferred to a Buffalo hospital, and discharged on Jan. 11.

Cardiac arrest affects the heart muscle’s electrical system, causing the heart to suddenly stop beating. It can be the result of a heart attack (blocked blood flow to the heart), a heart rhythm problem or trauma.

In Hamlin’s situation, experts speculate that the blow to his chest may have happened at a vulnerable moment in his heart’s electrical cycle.

The suspected mechanism of cardiac arrest is referred to as commotio cordis, which occurs when a person is hit in a precise area of the chest at a precise moment during a heartbeat, triggering a dramatic change in heart rhythm. When the heart stops, other vital organs cannot receive blood. In that instant, time is critical.

Cardiac arrest is often fatal without immediate treatment. After a person loses consciousness, the chance of survival decreases by 10 percent every minute. About 9 in 10 people who experience cardiac arrest outside the hospital do not survive.

Quick action helps save lives. Cardiopulmonary resuscitation (CPR) can get the heart beating normally again. If there is no pulse, an automated external defibrillator (AED) can help restore a normal heart rhythm. When performed in the first few minutes of cardiac arrest, CPR and use of an AED can double or even triple a person’s chance of survival.

“We can only speculate as to the cause of cardiac arrest in this case. While the optics suggest commotio cordis as the mechanism, this is a diagnosis of exclusion. The most important message from this event is the benefit of immediate CPR and availability of AEDs at public venues and all sporting events,” says Moeen Saleem, M.D., a cardiac electrophysiologist with Midwest Cardiovascular Institute and on the medical staff at Edward Hospital.

Although commotio cordis cases are very infrequent, with less than 30 cases reported each year in the U.S., it occurs more commonly in younger athletes as the chest wall is less developed compared to adults. Common sports for this to occur include baseball and lacrosse, due to impact from a hard ball to an unprotected chest.

Aside from blunt trauma to the chest, other causes of sudden cardiac arrest include undiagnosed heart conditions such as cardiomyopathy (hypertrophic, which is a thickened heart muscle, or dilated, which is an enlarged heart chamber), myocarditis (scarring of the heart muscle due to inflammation from a viral infection) or genetic conditions such as long QT syndrome.

“Events like this are tragic and impactful on an entire community. We are all hoping for a full recovery for Damar and any individual stricken by cardiac arrest. We should also take this as a reminder to educate ourselves to recognize cardiac arrest and the critical steps for resuscitation,” says Dr. Saleem.

Since cardiac arrest often occurs without warning, it’s important to know steps to take if it happens. Signs that someone is in cardiac arrest include being unresponsive, not breathing or gasping for breath.

Call 911 and begin CPR immediately. If the person collapsed, find an AED and use it as right away. Performing CPR and using an AED in the first few minutes of cardiac arrest can be lifesaving.

Do you know CPR? Everyone should know how to perform CPR, and you don’t need formal training. The American Heart Association describes how to perform Hands-Only™ CPR to the beat of the song “Stayin’ Alive.”

Join us for an American Heart Association's Family & Friends CPR course, which teaches adult Hands-Only CPR, Child CPR, Infant CPR and how to relieve choking in an adult, child or infant. Various dates offered this winter. Learn more and register.

Edward-Elmhurst Health is a national leader in heart care. We treat more than 40,000 heart and vascular patients annually. Learn more about our expert heart and vascular services.

Know your risk for heart disease. Take a free, 5-minute test that could save your life.

Related blogs:

• You could save someone’s life with Hands-Only™ CPR
• What’s the difference between cardiac arrest and a heart attack?
• Testing for conditions that could put teens at risk for sudden cardiac arrest