Cardiac (Exercise) Stress Testing

An exercise stress test is a general screening tool to test the effect of exercise on your heart. The test gives a general sense of how healthy your heart is.

During the test, the electrical activity of the heart is measured while you walk on a treadmill or pedal a stationary bicycle. This measures the heart's reaction to your body's increased demand for oxygen. (See also sestamibi and thallium stress tests.)

How the test is performed

You will walk or pedal on an exercise machine. An electrocardiogram (ECG) is used to record the activity of your heart and blood pressure readings are taken. The response of the heart to this increased workload is monitored.

The test continues until you reach a target heart rate, unless complications such as chest pain or an exaggerated rise in blood pressure develop with activity. Monitoring continues after exercise for 10 - 15 minutes, or until the heart rate returns to baseline.

How to prepare for the test

• Do not eat, smoke, or drink beverages containing caffeine or alcohol for 3 hours before the test.

• Continue all medications unless instructed otherwise.

• Wear comfortable shoes and loose clothing to permit exercise.

• Tell your doctor if you are taking sildenafil citrate (Viagra) and have taken a dose within the past 24 hours. A medication called nitroglycerin, which is sometimes given during a stress test to relieve chest pain, should not be given to a person who has recently taken Viagra, because it can cause a serious drop in blood pressure.

How the test will feel

Electrodes (conductive patches) will be placed on your chest, arms, and legs to record the heart's activity. The preparation of the electrode sites on your chest may produce a mild burning or stinging sensation.

The blood pressure cuff on your arm will be inflated every few minutes, producing a squeezing sensation that may feel tight. Baseline measurements of heart rate and blood pressure will be taken before exercise starts.

You will start walking on a treadmill or pedaling a stationary bicycle. The pace of the treadmill will be increased.

Rarely, people may experience chest discomfort, palpitations, dizziness, or shortness of breath during the test.

Why the test is performed

A stress test is performed to determine causes of chest pain, to determine the exercise capacity of the heart , to determine appropriate exercise levels in those initiating an exercise program, and to identify rhythm disturbances during exercise. There may be additional reasons for your health care provider to request this test.

Normal Values

Normally, heart rate increases in proportion to the workload and attains endurance levels appropriate for age and conditioning level.

What abnormal results mean

Abnormal results may indicate arrhythmias during exercise, stress on the heart provoked by exercise, possible coronary artery disease, i.e., blockage in the arteries, or lack of aerobic fitness.

What the risks are

Stress tests are generally safe. Some patients may have chest pain or may faint or collapse. A heart attack or dangerous irregular rhythm rarely occurs, but if it does, the patient is in the best position to receive medical attention.

Patients who are likely to have such complications are usually already known to have weak hearts, so they are not given this test.

Special considerations

A stress test is less accurate in young or middle-aged women with symptoms that are not typical of heart disease.