Just How Stressful Is A Stress Test?

Taking a stress test has almost become a rite of passage for middle-aged executives. But these tests to detect coronary artery disease--the No. 1 killer in the U. S.--aren't always necessary, especially if you don't experience such telltale symptoms as chest pains or shortness of breath.

So how do you know if you need one? Adolph Hutter Jr., a cardiologist at Massachusetts General Hospital in Boston, recommends the procedure if you are over 40 and meet at least two risk factors: a family history of heart disease before age 55, a cholesterol level of at least 240, and blood pressure higher than 160/90. Smokers, diabetics, and sedentary people embarking on an exercise program are also at risk.

Once you decide to proceed, a doctor will take a resting electrocardiogram (EKG) reading to measure your heart's electrical activity. Then you climb on a treadmill. There, the doctor will attach 12 metal disks on wires from the EKG monitor to your chest. Then you walk and run on the treadmill for about 10 minutes while the doctor monitors blood pressure, heart rate, and the EKG.

The test, designed to detect obstructed arteries, has drawbacks. The chance of its picking up significant blockage is 65%. Even if it does, it may not pinpoint location. And there's a high rate of false positives, especially in women.

A thallium screen, for $700 to $1,000--about three times as expensive as the basic test--is more accurate. At the peak of exertion on the treadmill, a radioisotope that illuminates the blood enters your bloodstream through an intravenous line. Then the patient lies down, and a special camera photographs the blood flowing through the heart. The pictures do a better job isolating areas of blockage.

WATCH YOUR DIET. Most insurers will cover either type of stress test if a patient displays symptoms. Otherwise, traditional plans often deny coverage. But managed-care programs that encourage preventive care, such as health maintenance organizations and preferred provider plans, will generally pick up the bill.

When a stress test shows a blockage, it's not the end of the world. Many patients get treated with medication or, in severe cases, with bypass surgery. In one-third of cases, just exercising and watching your diet can reduce the obstruction.

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