William Shatner almost died on the operating table while undergoing hip replacement surgery last month.
The 76-year-old developed an irregular heartbeat under anesthetic during the operation at LA's Cedars-Sinai Medical Centre on January 25.
A hospital source told the National Enquirer: "The hip replacement surgery went fine, but William's heart started beating erratically. For a few seconds, it looked like he might die on the table.
"Our doctors quickly stabilised him but he was pretty shaken up when they told him about the heart complication."
The insider said Shatner is paying more attention to his health following his close shave, saying: "Until now William has had no real medical problems. But he's overweight and out of shape, so hearing he had a heart problem scared the hell out of him.
"He said he's going to drop some weight and start taking better care of himself. The incident really shook him up. He's trying to process the whole ordeal as a wake-up call."
Shatner recently admitted that he is still unhappy about the demise of Captain Kirk in the movie Star Trek: Generations.
