Actor-comedian Jamie Kennedy is better known for cracking jokes than cracking chests, but starting Tuesday, he'll be playing a doctor in NBC's new medical drama Heartbeat.

And not just any doctor: Kennedy's character is a cardiothoracic surgeon.

"I'm cracking chests, and I'm also [operating on] muscle and tendon. I forget the actual name of it. But he [his character, Evelyn Callahan], has two boards," meaning he's certified in two specialties, the Upper Darby native said in an interview after an NBC news conference in January.

"People will say, 'Oh, you're a doctor?' " and they laugh, Kennedy said, acknowledging that some fans of his earlier work, including the old WB's The Jamie Kennedy Experiment, may not expect to see him in a medical drama.

"I have a beard now, I'm in my 40s, and when I first came on the scene I was in my 20s, so . . . I'm transitioning into middle adulthood here."

The people who laugh also "don't realize that doctors are very flawed beings, brilliant at their job - not all of them, but that's my character. My character is somebody who's really brilliant at his job, but terrible at everything else."

Plus, "this show has a lot of craziness."

Do tell.

Heartbeat stars Melissa George (Grey's Anatomy) as cardiothoracic surgeon Alex Panttiere, who's also the "chief innovation officer" at her hospital, a job that apparently empowers her to plow ahead every week with surgeries and experimental treatments that the hospital's COO (Shelley Conn) and its new chief of surgery (Don Hany) consider too dangerous.

Inspired by a memoir, Heart Matters, by Kathy Magliato and, to some extent, by Magliato's experiences as one of the few female cardiothoracic surgeons in the world, the show has given George's character a personal life that's maybe a bit more colorful than Magliato's.

"Kathy does not have as many lovers as I do on the show," George told reporters.

"I'm working on it," joked Magliato, who's also a co-executive producer.

George and at least one of her costars, Dave Annable, observed surgeries to prepare for their roles, George telling reporters that if teenagers could see an open-heart surgery, and "the beauty of a heart," they'd eat well and exercise to take care of theirs.

Kennedy, 45, is not convinced.

"I don't think that's going to stop me eating my brie," he said afterward.

But, then, the Monsignor Bonner grad may have cut a corner or two on his Heartbeat homework.

"All of these guys are talking about how they watched all the surgeries. Uh, there's something called YouTube," he said. "And I just watched a few there."

So maybe he didn't get the full effect?

"I could look at the heart; I could take it apart. I'm still going to eat paté sometimes."