What happened to Damar Hamlin? Doctor explains cardiac arrest after Buffalo Bills player collapses on field

Buffalo Bills player Damar Hamlin collapsed on the field Monday night after he suffered cardiac arrest.

"A heart attack is when there's interruption of the blood flow to the heart due to blockage in the artery that can result in a cardiac arrest, where the heart basically, the electrical activity, is interrupted. And so there's no mechanical activity, no blood flow to the brain. Patients pass out," said cardiologist Dr. Shukri David, with Ascension.

David said he does not believe Hamlin had a heart attack.

Read: Hamlin's family releases statement thanking supporters

"It's unlikely in a 24-year-old to have atherosclerotic coronary artery disease. When we do see a sudden cardiac death in athletes, it's usually during hypertrophic cardiomyopathy, anomalous coronary arteries, WPW rhythm problems. This is most likely due to contact injury right at a specific time in the cardiac cycle. The rhythm is interrupted and they go into what we call ventricular fibrillation. It's an electrical abnormality," he said.

CINCINNATI, OH - JANUARY 2: Damar Hamlin #3 of the Buffalo Bills is driven off the field in an ambulance after sustaining an injury during the first quarter of an NFL football game against the Cincinnati Bengals at Paycor Stadium on January 2, 2023 i

David said getting care quickly is key, and he is optimistic that Hamlin, who was last listed in critical condition, will recover.

"Critical in this particular case. In the early 70s, survival was about 20%. Today it's over 60-70% If we can get to the patient early enough with defibrillation, CPR, and to a facility that can handle cases like that. But early defibrillation or these automated external defibrillators are critical," David said. "I'm very optimistic because they did CPR immediately. It was recognized immediately. They did a defibrillation immediately, and then they got him to a facility. So, fingers crossed, But we've seen a lot of this, if it's a witnessed cardiac arrest, just like in his case, on national television, there's teams there. I'm very optimistic he's going to turn around."