CLEVELAND (WJW) — With prayers on the field and outside a Cincinnati hospital, players and fans showed support for Buffalo Bills safety Damar Hamlin.

The 24-year old NFL star’s heart stopped after a hard tackle, and while we still don’t have an exact cause of his cardiac arrest, medical experts said the impact could have triggered a rare heart condition.

“Something called commotio cordis — that would be on our differential diagnosis. But you can’t really make that diagnosis simply by watching a picture. You have to know more about underlying parts. Does he have an undiagnosed cardiomyopathy or other genetic cardiac condition?” said Dr. Michael Emery, co-director of the Cleveland Clinic Sports Cardiology Center.

Emery said commotio cordis occurs when the heart is struck at a very precise moment in its beating — a 40-millisecond window — causing an irregular surge of electricity leading to cardiac arrest, even in those without pre-existing heart issues.

“It was sort of bad timing and bad susceptibility that you were in the right place at the right time and get struck by the right kind of object,” he said.

Speaking in generalities, doctors say commotio cordis is very rare in football and more common in so-called throwing sports like baseball, hockey, lacrosse and softball.

The condition has mostly been reported among adolescents, but in some cases have been reported among people older than 20.

As far as long-term effects and possible outcomes for Hamlin, doctors said we simply have to wait to see.

” … The longer defibrillation and return of circulation takes, the lower the survival chances — which is why an emergency action plan, prompt recognition, prompt CPR and a prompt defibrillation are so important to survivability of a cardiac arrest,” Emery said.