What is a heart attack?

Jeopardy! host, Alex Trebek was hospitalized Tuesday after suffering a mild heart attack. Trebek, 67 was admitted to Cedars-Sinai Medical Center late Monday night and was expected to remain there about two days for tests and observation, said show spokesman Jeff Ritter. Alex Trebek is 67?!? I would have never guessed...he looks fantastic! Get well soon! (Source)