By William R. Condos, Jr., M.D.
Medical Director,
Cardiocascular Institute of the South /Lake Charles

The nation's longest-running heart study suggests that about one heart attack in four produces no symptoms -- or at least none that the victim associates with a heart problem.

These so-called "silent heart attacks", however, are only the most extreme case of a still more prevalent condition called "silent ischemia" -- a chronic shortage of oxygen- and nutrient-bearing blood to a portion of the heart. Both conditions put their victims at significant risk.

The cause of ischemia, silent or otherwise, is almost always atherosclerosis -- the progressive narrowing of the heart's arteries from accumulations of cholesterol plaque. In most instances, this reduction in blood supply generates a protest from the heart -- the crushing pain called angina. But in perhaps 25 to 30 percent of heart attack victims, there were no previous symptoms of these gradually developing blockages. And, as we've already noted, the Framingham heart study, which has followed 4,000 Massachusetts men for more than 40 years, has found that 25 percent of their subjects' heart attacks go unnoticed until their annual EKGs detect their after-effects.

The absence of pain, however, doesn't mean an absence of damage. The heart has a built-in reserve capacity, allowing it to suffer a certain amount of scarring and weakening from a heart attack and continue to meet the body's needs. But further ischemia or another heart attack -- even a mild to moderate one -- may prove fatal, because that reserve capacity is no longer there. Even those who survive another heart attack are at increased risk of becoming cardiac cripples, disabled by congestive heart failure or arrhythmias -- heartbeat irregularities.

There is no way of predicting absolutely who is a candidate for silent ischemia, but, statistically, the greater the number of risk factors for coronary artery disease that you have, the more likely you are to be a candidate. Those risk factors include some you can't control -- your age, sex and genetic predisposition to atherosclerosis -- and those you can influence, like diabetes, high blood pressure, high blood cholesterol, smoking, lack of exercise and obesity.

As a rule of thumb, I would urge you to undergo a screening for silent ischemia if you have any three of these factors working against you -- a man over age 50 who smokes, or a post-menopausal woman with a ten-year history of diabetes and chronic unfavorable blood cholesterol levels, for instance.

The screening for undetected ischemia is a medical history and physical examination and a cardiac stress test -- a workout on a treadmill while your heart function is monitored.

It's a simple, painless and inexpensive way to learn whether the beating of your heart is accompanied by the inaudible ticking of an atherosclerosis time bomb that could kill you.

&copy 1995 Cardiocascular Institute of the South

For further information, call Jane Arnette, Cardiocascular Institute of the South/Houma, 1-800-425-2565, or Jim Keyser at 1-800-848-2715. E-mail questions or comments to: jakeyser@cardio.com.

Return to the CIS Home Page.

The material contained herein is provided for informational purposes only and should not be considered as medical advice or instruction. Consult your health care professional for advice relating to a medical problem or condition.

This information has been reprinted with permisssion and has been provided to you via Med Help International (a non-profit organization). Questions, comments, and donations may be sent to: