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

You will walk or pedal on an exercise machine while the electrical activity of your heart is measured with an electrocardiogram (ECG), and blood pressure readings are taken. This will measure your heart's reaction to your body's increased need for oxygen.

The test continues until you reach a target heart rate, unless complications such as chest pain or an exaggerated rise in blood pressure develop. You will continue to be monitored for 10 - 15 minutes after exercising, or until your heart rate returns to baseline.

• You must not eat, smoke, or drink beverages containing caffeine or alcohol for 3 hours before the test.
• You should continue all medications unless instructed otherwise.
• Wear comfortable shoes and loose clothing to allow exercise.

Tell your doctor if you are taking sildenafil citrate (Viagra) and have taken a dose within the past 24 hours. This is necessary because 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, since the combination can cause a serious drop in blood pressure.

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 and incline of the treadmill will gradually be increased.

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

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

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

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

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.

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