Damar Hamlin's Cardiac Arrest Has Health Professionals Talking About Commotio Cordis

Nurse Beth, MSN

Football players understand that injuries are an occupational hazard. But what healthy 24 yr old, much less healthy 24 yr old professional athlete envisions a routine tackle turning into a life-threatening cardiac event? Certainly, neither Damar Hamlin, a fresh starter for the Buffalo Bills, nor even the team doctor could have predicted that before the big game was over, he'd be in ICU with a diagnosis of cardiac arrest.

On the day of the game, and following a helmeted hit to the chest, horrified fans watched as a televised Damar stood up, fell back, and then collapsed on the field. Damar Hamlin's heart was shocked and successfully restarted by emergency medical personnel.

The cause of Damar's sudden cardiac arrest is not clear. What is known is that he was successfully resuscitated and transported to the University of Cincinnati Medical Center, a Level One trauma center.

Damar Hamlin is removed from Paycor Stadium in an ambulance. The Buffalo Bills, in white, kneel in prayer at the bottom left of the image.

Commotio Cordis Explained

One possible explanation circulating in the media for what occurred is commotio cordis (kuh-MOH-shee-oh KOR-dis). Latin for "agitation of the heart,” commotio cordis is a rare cause of cardiac arrest and subsequent sudden death.

A blunt blow to the chest is essential to the diagnosis of commotio cordis. Not only a blow but a blow positioned over the left ventricle. Not only a blow positioned over the left ventricle but a blow at a precise and critical time of the cardiac cycle when the heart is vulnerable to outward stimulus.

Given that an entire cardiac cycle, or single heartbeat, often takes less than one second, the blow has to occur within milliseconds of ventricular contraction. Clinicians recognize this part of the cardiac cycle as repolarization, as evidenced by T waves on an EKG.

Dr. Marc Cohen, Chairman of the Department of Medicine at Newark-Beth Israel Medical Center, was quoted in the New York Post as saying...

Quote

That hit had to occur at a certain point in time that was only five milliseconds long ... If that hit occurred one millisecond after or before, this may not have happened.

In layman's terms- commotio cordis is a freak accident, on par with being struck by lightning.

In commotio cordis, there is no real physical injury to the heart muscle or tissue, or rib cage, despite the blow. Instead, the devastating result of such a precisely timed and delivered hit is a disruption of the heart's normal sinus rhythm. The heart, while sustaining no physical injury, goes into a lethal ventricular rhythm called ventricular fibrillation, or VF.

Screening and Prevention

In an interview with Dr. Sam Singh, interventional cardiologist, the author asked if screening existed for commotio cordis. While Damar's health status is not known, Dr. Singh said that African Americans have a higher incidence of hypertrophic cardiomyopathy. Hypertrophic cardiomyopathy could contribute to disruptive rhythm disorders. An echocardiogram can easily identify cardiomyopathy.

Additional potential testing could include an EKG to screen for prolonged QTc intervals, which are associated with ventricular rhythms. In the absence of underlying conditions, a diagnosis of commotio cordis is arrived at clinically and by differential diagnosis.

Prevention in athletes with no underlying conditions is limited to chest wall protectors and padding.

Demographics

Commotio cordis is rare but deadly. It's so rare that it's guaranteed doctors and nurses are looking it up and educating themselves at the time of this reading.

The US Commotio Cordis Registry reports that 95% of commotio cordis occurs in males, primarily white males.

While rare, and with only 15-25 cases officially reported to the Registry each year, it's estimated that many cases go unreported. More cases occur in sports other than football, such as in baseball and hockey, where projectile balls and hockey pucks cause blunt-force trauma.

Ventricular Fibrillation (VF)

VF is the real culprit. VF is a lethal rhythm that quickly causes sudden death. If Damar had been monitored at precisely that millisecond of time referred to above, there may well have been a visible PVC (premature ventricular contraction) or two, followed by VF.

VF is a chaotic rhythm in which the heart, having no organized contractions or electrical activity, quivers lethally and impotently. As a result, there's no blood flow to the brain or to any vital organs, including to the heart itself.

Nursing Care

From a nursing standpoint, care is supportive with close monitoring. Treatment for commotio cordis is the treatment for a cardiac arrest.

Be aware that patients may have a complete heart block, a left bundle branch block, elevated ST segments in V1-V3, and even idioventricular escape rhythm. All of these are transient and limited to 2-3 days post-event.

Nurses Must:

Monitor in more than 1 lead to pick up potential changes in V leads
Anticipate that EKGs and echocardiograms are typically normal
Closely monitor and measure QTc intervals
Report prolonged QTc intervals as they can increase the risk of sudden death
Anticipate ambulatory Holter monitoring
Provide patient and family reassurance, support, and education

Shout Out to First Responders

FACT: Commotio cordis is usually fatal. Without a doubt, what saved Damar's life were the highly trained medical personnel and technology immediately available to him.

As nurses, it's crucial to be response-ready with resuscitation skills both in and out of the hospital. At any time, any one of us could be called upon to respond to an emergency in the field. In Damar's case, prompt response proved that minutes count, and time is muscle, as we all recall from our CPR and ACLS training.

It's also a reminder of how important bystander CPR and AED (automated external defibrillator) equipment are.

Thankfully Damar Hamlin survived his encounter with commotio cordis and hopefully will make a full recovery.

References/Resources

Dunleavy, Ryan (2023 January 3). Cardiologist explains how Damar Hamlin's cardiac arrest may have happened. Retrieved 1/03/2023.

Maron BJ, Haas TS, Ahluwalia A, Garberich RF, Estes NA 3rd, Link MS. Increasing survival rate from commotio cordis. Heart Rhythm. 2013 Feb. 10(2):219-23.

Yadek, S. (updated 2023, January 3). Common Cordis. Retrieved 1/03/2023.

Singh, Sam, MD. Dr. (Sam) Sarabjit Singh, MD. FACC, FSCAI. Board Certified Cardiologist. Interview conducted 1/03/2023.

AHA: Commotio Cordis