ET has learned exclusively that Kelsey Grammer has been hospitalized in New York and has cancelled four television appearances today. The actor, who was in town to promote 'Swing Vote,' began feeling faint and went to the hospital. We've learned Kelsey's condition could be the result of medication he was taking for his heart attack, which happened a little less than two months ago in Hawaii.

We're told the medication has now been modified and Kelsey will remain under observation for one more day. Just last week, Kelsey talked to our Mary Hart about his miracle recovery, revealing that his health scare was a lot more serious than was first reported. "We originally said it was just a mild heart attack, and it actually wasn't very mild," Kelsey said. "They had to blast me twice and get me started all over again."