Hulk Hogan -- My Heart Isn't Broken

Hulk Hogan had a big medical scare this week -- after doctors thought they may have found an abnormality with the wrestler's heart.

Hogan was undergoing tests for back surgery, when doctors discovered a problem with his EKG.

Sources close to Hulk tell us the back doc sent Hulk to a specialist at a cardiovascular medical center in Florida for further testing.

But this story has a happy ending -- we're told doctors ran more extensive tests and were able to determine that Hulk's ticker is working just fine ... though we're told Hulk was "very worried" during the process.