Should a healthy person with no risk factors or symptoms of heart disease get an exercise stress test? It depends.

Exercise stress tests are used to detect abnormalities in the electrical activity of the heart not present at rest. Most often the test involves walking on a treadmill while attached to wires which hook you up to an electrocardiogram (ECG) machine.

You will exercise for up to 20 minutes or until you become too tired or short of breath, develop chest pain, a dangerous change in blood pressure, or clear evidence of heart disease on the ECG. Every three minutes, the incline and speed of the treadmill are increased. Your blood pressure and heart rate are followed during and after the exercise.

An exercise stress test is a good idea for people with chest pain that may be caused by angina, and possibly for those with several risk factors for heart disease. Some of my colleagues order a stress test in people who have extremely elevated levels of only a single risk factor, such as high blood pressure or LDL cholesterol, associated with a particularly high risk of a heart attack.

I will never forget my failure to get a stress test in a 55-year-old woman who had very high LDL cholesterol levels and a family history of the condition. She died suddenly of a heart attack.

What if you have no risk factors for heart disease? At this time, the American Heart Association (AHA) does not recommend exercise testing in people with no symptoms of heart disease, except possibly in the following circumstances:

• When people who have diabetes or are over the age of 45 for men or 55 for women plan to start a vigorous exercise program.
  
  
• When a doctor is undecided whether to begin aggressive preventive measures, such as statins to lower LDL cholesterol, in people with borderline risk factors.

According to the AMA, a false positive test (one suggesting heart disease when it is not present) is common in people without symptoms, especially women. False positive tests can result in unnecessary tests and medications that carry their own risks and costs.

I believe it is worthwhile for asymptomatic men over 45 and women over 55 to have a stress test if they have diabetes, kidney disease, multiple risk factors, or extreme abnormalities of a single risk factor.

Studies also show that the rate at which the heart rate returns to normal after exercise, and how long a person can exercise during a stress test provide other important information beyond the heart's electrical activity recorded by the test.