A man suffered an apparent heart attack while eating a "Triple Bypass Burger" at the Heart Attack Grill in Las Vegas.

The man, whose identity has not been released, was eating by himself when he began complaining of chest pains, started sweating and stuttering his words, said Jon Basso, the restaurant's owner.

"I was in the back cooking and the nurses came back and said 'someone is having a heart attack,'" said Basso.

At first Basso didn't believe it because in the hospital-themed restaurant, where wait staff wear sexy nursing uniforms, and the diners are outfitted with hospital gowns, the employees and customers sometimes role play.

"No, he's really having an f-ing heart attack," one of the employees told Basso, he said.

Basso, who goes by the name "Dr. Jon" in the restaurant, and who plays the role in a white doctor's coat and stethoscope, called an ambulance and paramedics were quickly on hand to treat the man, who Basso described as a normal, "run-of-the-mill" guy in his 40's.

The customer was reportedly recovering in a nearby Las Vegas hospital after the attack, said Basso, who is not a doctor.

The burger joint, whose slogan is "taste…worth dying for," is known for its self-proclaimed unhealthy food. A sign on the front door reads, "Caution: This Establishment is Bad for Your Health."

In addition to the now infamous bypass burgers, diners can also enjoy fries cooked in pure lard, and butterfat shakes. A huge neon sign above the restaurant's door advertises "Over 350 Lbs Eats Free".  But they must prove it, by weighing in on a scale in the middle of the restaurant.

So what's on that Triple Bypass Burger?  Three half-pound hamburger patties with buns dipped in lard, half of an onion cooked in lard, a whole tomato, 15 pieces of bacon, cheese, and special sauce.

Estimated at 6,000 calories, Basso stated the obvious when he said, the "burgers are higher cal than your typical burgers."

The restaurant also serves the "Quadruple Bypass Burger," estimated at 8,000 calories.

But "Dr. Jon" says calorie count may be irrelevant; heart attacks are a genetic issue. er, he said ultimately, heart attacks are a genetic issue.

In an interview with ABC News last year,  Basso said his food can be viewed as "absolutely evil."

"I genuinely hope that people continue to eat in a sinful way, but moderately," he said. "I don't want to see everyone come into my restaurant every day.  It's a once a week, cheat day thing."

Basso used to own a Jenny Craig franchise and fitness center, but left the fitness business because he did not feel he was reaching anyone, he said.

The Heart Attack Grill came under fire last year when its spokesman, 6'8?, 570-pound, Blair River died last year of pneumonia at age 29.  It is not possible to say what role River's weight played in his death.

"I hired him to promote my food," said Basso.  "We are absolutely guilty of glorifying obesity."

On Saturday evening, customers close enough to see the customer having a heart attack were "mortified," said Basso.

Tourists were less sympathetic, apparently thinking they were witnessing nothing more than a fit of acting or a publicity stunt - since the restaurant sometimes wheels healthy customers in an out of the restaurant on wheelchairs.

"It was horrible, the tourists were saying 'hold on, slow down, let me get a shot," Basso said.