OMAHA — After Buffalo Bills safety Damar Hamlin collapsed after making a tackle during a Monday night game, football fans were left wondering what could have felled a fit 24-year-old.
The Bills said in a statement early Tuesday that Hamlin had suffered a cardiac arrest following a hit during the team’s Monday night game against the Cincinnati Bengals.
Hamlin was given cardiopulmonary resuscitation, or CPR, on the field. His heartbeat was restored before he was taken by ambulance to the University of Cincinnati Medical Center, the team said. He was sedated and listed in critical condition.
While the team has not yet indicated what caused Hamlin’s heart to stop, cardiologists say one possibility is a rare condition called commotio cordis.
Commotio cordis occurs when a person suffers a blunt trauma, or blow, to the chest wall in front of the heart during a specific time in the cardiac cycle that lasts only milliseconds, said Dr. Anuradha Tunuguntla, an interventional and structural cardiologist with CHI Health Nebraska Heart in Lincoln.
“It’s a very narrow window when the ventricular muscles are actually relaxing, called ventricular polarization,†she said.
The ventricles are the lower chambers of the heart responsible for pumping blood — the right ventricle sends blood to the lungs to pick up oxygen, the left pushes oxygenated blood out to the body.
Activating the muscles while they’re relaxing, she said, can disrupt the cardiac cycle, cause an abnormal rhythm and lead to cardiac arrest.
Only about 200 cases of commotio cordis have been reported since 1995, Tunuguntla said. However, she said she believes the condition is underrecognized and therefore underreported.
Hamlin’s collapse, she acknowledged, could have been caused by something else. But most cases of commotio cordis occur in the same way Hamlin’s arrest unfolded, with a blunt trauma followed by a sudden collapse.
After the impact, Hamlin quickly got to his feet, then fell backward about three seconds later and lay motionless, The Associated Press reported.
Survival in such situations, Tunuguntla said, depends on the quick delivery of effective CPR, along with the use of an automated external defibrillator, or AED, to shock the heart into rhythm. If that is done within two minutes, outcomes are much improved.
WXIX-TV in Cincinnati reported that Hamlin was treated with an AED in addition to CPR on the field.
In the early 1990s, only about 10% of people survived the condition, she said. But the latest data indicates that survival rate has improved to about 60%.
The condition is seen mostly in athletes between ages 8 and 18 who play sports involving balls and pucks, such as baseball and hockey.
Quick and effective CPR is critical for anyone in cardiac arrest, she said, because the chest compressions help keep blood flowing to the brain and other organs until an AED is available.