Oct. 26, 2004 -- -- Former President Clinton realizes the warning signs of heart disease began long before he had quadruple heart bypass surgery, and he has one message for the public: Don't ignore your body.
"The number one thing I would say to people is if you've got a family history, you gotta be tested, tested, tested," Clinton told ABC News' Diane Sawyer in an exclusive interview that aired today on "Good Morning America."
"You should bend over backwards to make sure you get the medicine that you need and watch your diet. And the only signals are not, you know, where your chest is hurting so bad you can hardly stand up, and you're on the verge of a heart attack. … It may be sustained shortness of breath or inability to do things you used to do. You just can't assume it's the aging process."
"I just missed it [the warning signs]," Clinton continued. "That was my fault. I don't blame my doctors or anybody else. … I was insufficiently vigilant."
Seven weeks after his Sept. 6 surgery, Clinton joined Democratic presidential hopeful John Kerry on the last full week of his campaign before the Nov. 2 election. The so-called "Comeback Kid" -- noticeably thinner but exuberant -- appeared at Kerry rallies in Pennsylvania and Florida on Monday and plans to campaign for the Massachusetts senator this weekend in Nevada, New Mexico and his home state of Arkansas.
Doctors said Clinton had nearly 100 percent blockage in some of his arteries when he underwent surgery and had narrowly avoided having a major heart attack. Clinton said he believes he began experiencing the symptoms of heart disease shortly after he left the White House -- even though he was exercising and, he believed, in good physical condition.
"I worked out with a trainer. I was in the best shape of my life," Clinton said. "Still, when I'd go out for a run, after a mile I'd have to stop and walk 100 yards or 200 yards to get my breath. And then I could run again."
Clinton said he continued to feel periodic shortness of breath and tightness in his chest after exercising into the spring of 2004. But he always attributed them to other factors.
"I had several instances where my chest felt tight when I was exercising," he said. "And because I could, you know, slow down and then resume that level without tightness returning, I just assumed it was because I was exhausted, and I was out of shape."
However, this past summer, Clinton noticed he was have increasing difficulty with physical activity. Eventually, he began to feel shortness of breath and tightness in his chest when he was not physically active. Clinton said he felt severe tightness in his chest after a book tour on Aug. 31 in New Orleans.
"Each time he exercised, he was feeling this," said Dr. Allan Schwartz, Clinton's cardiologist. "And the symptoms were gradually getting worse, occurring at a lower and lower threshold. … The episode that landed him in the hospital was an episode of symptoms at rest lasting 20 to 30 minutes."
Clinton's symptoms did not show up in a stress test, which lasts between 12 and 15 minutes. And since his cholesterol levels fluctuated, he was reassured into stopping taking his cholesterol medication, Zocor.
But Clinton does not blame his doctors for taking him off Zocor.
"To be fair to them, they used the latest standards for what [bad] cholesterol was," he said. "And my cholesterol was below that. And it's much lower now."
Clinton blames himself -- a bad diet, a busy work schedule and ignoring warning signs -- for his health ordeal.
"Since I left the White House, maybe if I had stayed on a lower fat diet. Maybe if I had … not eaten so many hamburgers and steaks, which I love, maybe if I had, you know, had slightly less stress in my life … maybe it would have been different," he said.
In his first interview since his surgery, Clinton said his wife, Sen. Hillary Rodham Clinton, was not worried that he was returning to political activities too early, but she didn't want him to do too much, either. When he was first released from the hospital, she made sure that he didn't field too many phone calls.
"She was afraid I'd be on the phone too quick when I came home. And so we rerouted our phones to the office," Clinton said. "And it was interesting. We got 100,000 e-mails, 10,000 letters, and hundreds and hundreds of calls. And they organized the phone calls for me, and I'm answering them a little along as I can."
Still, Clinton does not think he is taking a risk by hitting the campaign trail for Kerry so soon after surgery. The race between Bush and Kerry is too close to call, Clinton said, and the consequences are monumental.
"I want to do this," Clinton said. "Senator Kerry asked me to do it, and I want to do it. And … because it's [the race for the White House] close and because I think it's important. And because the differences between the two candidates and the courses they'll pursue in the next four years are so profound."
The rest of Diane Sawyer's interview with Clinton will air Thursday on "Primetime Live."