Distress, sudden exercise raise heart attack risk
July 27, 1999
Web posted at: 10:45 AM EDT (1445 GMT)
By Daniel Hayes, M.D.
|Heart disease: The numbers|
| About every minute an American will die from heart disease, or coronary artery disease (CAD).|
| One out of every five deaths in the United States is caused by CAD.|
| About 80 percent of CAD deaths in people under 65 occurs during the first heart attack.|
| In 57 percent of men and 64 percent of women who died suddenly of CAD, there were no previous symptoms.|
| About two-thirds of heart-attack patients don't make a complete recovery, but 88 percent of those under age 65 are able to return to their usual work.|
|Source: American Heart Association|
A group of recent studies has provided new information about heart attacks and the role physical and emotional exertion and depression play in their occurrence. This new information, in addition to a finding about blood-cholesterol levels, may help to reduce the risk of heart attack, the No. 1 cause of death in the United States.
What causes coronary heart disease?
Coronary heart disease, also known as coronary artery disease (CAD), occurs when narrowed or diseased coronary arteries supplying blood to the heart become clogged. One way this can happen is when a blood clot (thrombosis) partially blocks the coronary artery. Another way is when cholesterol-containing plaques on the inside of the coronary artery break open, causing a clot to form that blocks the flow of blood.
The danger of sudden emotional stress
A study in the March issue of the Journal of the American Medical Association (JAMA) provides new insight into heart-attack risk associated with emotional exertion and exercise.
Researchers led by Dr. Allen P. Burke examined the hearts of 141 men with severe coronary artery disease who had died suddenly. The investigators found that a cholesterol plaque had ruptured and caused a heart attack in 68 percent of the men who had died during exertion or extreme emotional stress; only 23 percent of men who had died at rest had ruptured plaques. "In men with severe CAD who die suddenly, acute exertion appears to be an independent risk factor for plaque rupture, presumably by disruption of a vulnerable plaque," the authors write.
The study results have prompted experts to recommend that people with high cholesterol who plan on beginning or increasing an exercise regimen first lower their cholesterol to keep heart-attack risk minimal.
"I don't want to frighten people and stop them from exercising. What I do believe is that if you have a very high cholesterol, and you have never exercised, a physician must lower (your) cholesterol before putting (you) on an exercise program," explains Dr. Renu Virmani, co-author and chairman of the Department of Cardiovascular Pathology at the Armed Forces Institute of Pathology in Washington, D.C.
Dr. Jacob Varghese, director of the coronary-care unit at George Washington University Hospital, agrees, adding, "There is some data to support that, if an individual is getting involved in an activity which is unusual for him, there is a chance that that physical exertion might result in a plaque rupture." Varghese does add, however, that if someone is performing physical exercise that he does every day, his risk of plaque rupture does not appear to be significant.
Distress can be reduced in order to lower a person's heart-attack risk, says Dr. Meyer Friedman, of the Meyer Friedman Institute in San Francisco. Effective techniques for reducing this distress include relaxation and behavioral changes.
Cholesterol levels following bypass surgery
Coronary artery bypass graft (CABG) surgery is a common intervention for individuals suffering from CAD. Doctors use CABG to route blood intended for the heart around blocked coronaries using a portion of the patient's leg vein. However, these new bypass veins tend to develop cholesterol blockages as well.
A recent study published in Circulation, the journal of the American Heart Association, suggests that the progression of atherosclerosis in the grafts of patients can be slowed by significantly lowering the person's low-density lipoprotein cholesterol (LDL-C). The authors recommend lowering the LDL-C level below 100 mg/dl after bypass surgery "in women as in men, in the elderly as in young patients, and in patients with other coronary heart disease risk factors."
"It also makes sense, based on other recent evidence, to generalize these recommendations to patients with coronary artery (blockage) and elevated LDL-C," says Dr. Yves Rosenberg, medical officer at the National Heart, Lung and Blood Institute in Bethesda, Maryland.
The depression-heart attack link
Studies of patients with known coronary artery disease have shown that depression is associated with increased incidence, severity and death from heart attack.
In the June issue of American Heart Journal, researchers examined the effect of a newer antidepressant, sertraline, on patients who had developed depression following a heart attack. The antidepressant was found to be safe and effective. It did not cause the heartbeat irregularities caused by older antidepressants.
This small study has set the stage for a larger trial that will evaluate whether antidepressants can actually reverse the increased heart-attack risk associated with depression.
Copyright 1999 by WebMD, Inc. All rights reserved.
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Coronary Artery Disease
American Heart Association
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