Couch Potato Caveat: Start Exercise Carefully

Overweight, sedentary people should take it slow to avoid heart attacks when they finally get off the couch and start exercising.

A study found that people who are extremely inactive are more than 30 times more likely to have a heart attack during exertion than at any other time. Those who are just plain inactive are 21 times more likely.

"If you don't get much exercise and you're middle-aged with a lot of risk factors, you ought to be pretty careful about picking up that snow shovel," said Paul Thompson, one of the authors of the study in today's Journal of the American Medical Association.

The warning shouldn't be construed as an excuse to avoid exercise, the researchers said.

Out-of-shape people should begin exercise with caution and check with their doctors first, said Thompson and James Fletcher, a cardiologist with the Mayo Clinic in Jacksonville, Fla.

Fletcher said if the body is not accustomed to vigorous exercise and suddenly gets it, the circulation system becomes stressed, with blood pressure rising and the heartbeat increasing, which can lead to a heart attack.

The study of 640 patients at Hartford Hospital in Connecticut compared 64 people whose heart attacks were related to exertion with 576 whose heart attacks were not.

Of those whose heart attacks were related to exertion, 84 percent were inactive. Eighty-six percent were men and 62 percent had high levels of fat in their blood. Fifty-nine percent were smokers.

Infant Heart Surgery Survival Rate Climbs

The survival rate among children undergoing heart surgery has improved by one-third since the early 1980s, even though doctors are operating on younger and sicker patients.

While heart surgery is routine--and generally safe--for adults, the operations are much more difficult in the very young, whose plum-size hearts and delicate condition make complications common.

"We have had a very significant improvement in mortality," said James Moller of the University of Minnesota. "In the youngest age group, this has occurred even though more complicated operations are being performed."

Moller presented the latest data yesterday at a meeting in Atlanta of the American Heart Association. The figures were compiled by the Pediatric Cardiac Care Consortium, made up of 48 hospitals in 25 states and two Canadian provinces. The statistics covered 51,000 operations on children up to age 18 between 1982 and 1997.

Moller said that since 1982, overall mortality among the heart surgery patients has fallen from 9.6 percent to 6.2 percent. In babies under a year old, it has fallen from 20 percent to 11 percent. And in the youngest patients--those under 1 month--mortality has dropped from 26 percent to 17 percent.

Heart problems are the most common serious birth defect. In the United States, about 32,000 babies are born with these problems annually, and one-quarter of them need treatment, usually surgery.

Most of these difficulties involve either obstructions in the heart's valves and arteries or abnormal patterns of blood flow through the heart. Surgery can involve patching a hole, tying shut an opening or surgically widening a valve.