What’s it for?
An exercise stress test looks at how your heart performs while you are exercising. It can help reveal heart problems that may not show up when your body is at rest.
The standard exercise stress test uses an ECG to measure your heart’s electrical activity at rest and during exercise, when your heart needs more oxygen and must pump more blood.
Exercise testing can also be combined with imaging tests, such as an echocardiogram (stress echo) or nuclear ventriculogram, to produce detailed pictures of your heart under stress. People who are unable to exercise can have a stress test using chemicals that mimic the effect of exercise on the heart.
Exercise stress tests are used to:
- Determine your likelihood of having coronary artery disease
- Identify abnormal heart rhythms
- Evaluate the effectiveness of your cardiac treatment plan
- Help you develop a safe exercise program
How it’s done
Before you start exercising, the nurse or technician will determine your target heart rate (the number of beats per minute you are aiming for to be sure your heart is working hard) based on your age, height, and weight.
A blood pressure cuff will be placed around your arm, and you will be fitted with sticky electrodes attached to an ECG to monitor your heart’s electrical activity. For the standard test, a baseline ECG will be taken.
You will then begin to exercise on a treadmill or a stationary bike; the speed and elevation will gradually increase. When you have reached your target heart rate or when you ask to stop because of fatigue or symptoms, this portion of the test will end.
When an exercise stress test is used in combination with an echocardiogram or nuclear ventriculogram, images are taken before and immediately after the exercise portion (while your heart rate is still high). If the imaging test requires contrast dye, you may be injected with it while you are exercising so that it has time to spread through your heart before the images are captured.
Who should have this test?
Your doctor may order an exercise ECG alone or combined with an imaging test. Some people have no symptoms of heart failure when they are resting, so an exercise stress test is done to trigger your symptoms and monitor what is happening to the heart when they occur.
Who should NOT have this test?
If you are unable to perform physical activities due to older age, arthritis, excess weight, or other health problems, you may undergo a pharmacological stress test instead, in which you are injected with a chemical as a substitute for exercise.
If you are pregnant or breastfeeding, you should not have any kind of radiation procedure, including a stress nuclear ventriculogram.