Vanderbilt cardiologist gives possible explanation for Hamlin's 'rare' cardiac arrest

NASHVILLE, Tenn. (WZTV) — Damar Hamlin of the Buffalo Bills collapsed Monday night after suffering cardiac arrest, an incident that sent the team, coaches, and fans to their knees in prayer—and left Hamlin in critical condition.

The injury is sparking discussions about the causes of heart trauma and the dangers it may pose for athletes of all ages.

FOX 17 News spoke with Dr. Christopher R. Ellis, a physician who specializes in heart rhythm disorders at Vanderbilt University Medical Center.

Dr. Ellis says Hamlin’s injury is a rare event, occurring in about 1 in 50,000 people.

“About two thirds of the time, if we see someone who has cardiac arrest during exercise, it’s going to be from a genetic problem with an electrical ion channel in the heart muscle, or a structural heart problem where there’s a lot of scar tissue building up in the heart muscle.”

However, Ellis says a normal, “innocent” extra heartbeat that begins in one of the heart's two lower chambers—or premature ventricular contraction (PVC)—could spring the heart into ventricular fibrillation or (VF) and become deadly.

“When you go into VF, it takes a few seconds—probably three to six seconds—before blood flow to the brain stops and you will be unconscious. That looked like what may be consistent with what happened [to Hamlin].”

Ellis says another possible cause for Hamlin’s cardiac arrest is from something called commotio cordis.

“That’s basically really bad luck,” Ellis said.

ALSO READ: Titans' Rashad Weaver is heartbroken after seeing close friend Damar Hamlin collapse

So what is commotio cordis? Ellis explains this type of blunt trauma which occurs directly to the chest. He also notes the best chances of survival and recovery.

Your heart goes through an electrical cycle 60 times per minute, on average, possibly slower for some athletes.

But there’s a 10 or 20 millisecond interval where all of us are vulnerable to potentially having this happen. If that force can somehow cause a shock to the heart just at the right time, it may trigger VF in someone with a normal, heathy heart.

I think in his case, the key to survival is how quickly you get high-quality CPR started and get blood flow, at least partially, back to the brain.

And then, if it’s VF—as it appears it may have been—the quicker you cardiovert, the more likely you'll survive to a full neurologic recovery.

Ellis noted the importance of having an automated external defibrillator (AED) nearby. An AED is a device that looks for a shockable heart rhythm and delivers a shock only if needed. It's small, portable, automated and easy to operate.

Read about AED laws in Tennessee schools here.

Ellis adds that the highest reported rates for sudden death during exercise are with African Americans playing basketball.

ALSO SEE: Spokesman: Doctors tell Hamlin's family he is making progress in his recovery

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