Kelsey Grammer suffered a heart attack over the weekend, while he was vacationing in Hawaii.

"Kelsey's heart stopped for a few seconds, that's for sure," a source tells Star mag. "He was then admitted to the Kona Community hospital where he was treated. Soon after he was airlifted by helicopter to a hospital in Honolulu. I think he went for more tests there. The doctors treated this very seriously."

The Frasier star's rep confirms that the actor, who's 53, did indeed have coronary trouble while swimming on a beach in Kona, but called it a "mild heart attack." He also says that Kelsey will be back on his feet in no time.

"Kelsey is doing fine now and he will be going home tomorrow," his rep said.

Get well soon!