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An exercise stress test is a common screening used to help diagnose coronary artery disease (CAD) or a heart rhythm problem that is brought on by exertion—a time when the heart is working harder than it does at rest. A standard stress test uses an electrocardiogram (EKG) to measure changes in the heart’s electrical activity. Imaging stress tests produce pictures of how blood travels through the heart.
But stress tests are not appropriate in all situations, especially in an emergency. Some experts feel that if a patient has already had a heart attack or has ongoing chest pain, it may not be appropriate. A stress test is also not the right test to use as a routine screening for CAD in someone without symptoms or in someone with such conditions as diabetes. Usually, there should be symptoms—especially atypical chest pain (angina)—that suggest a stress test. Even in those situations, there are other tests, such as coronary angiography or cardiac computed tomography that may be better choices than a stress test.
Stress Test Odds
Sometimes, though, in established CAD there can be a role for stress testing on an individualized basis. Traditionally, doctors have avoided a stress test for patients with severe aortic stenosis, but at times, they may suggest a stress test—with appropriate monitoring and supervision—to measure the severity of aortic stenosis.
Although a stress test does carry risks, statistics show there is less than a 1-in-1,000 chance that a stress test may trigger a major complication, such as an arrhythmia or heart attack.
Imaging Stress Test Types
To get detailed images of how blood flows in the heart at rest and during physical activity, you may be advised to have a certain type of stress test.
- One is a nuclear stress test. Prior to this test, a radioactive substance such as thallium is injected into one of your veins. After you rest for several minutes, a special camera will take pictures of your heart to see how the substance is circulating through your heart. Then you’ll go through a regular stress test. When it’s over, you’ll receive another injection and more pictures will be taken. The first and second sets of images allow for a comparison.
- Another type of stress test includes echocardiography. A “stress echo” uses sound waves to create images of the heart at work. It’s often used when heart valve disease is suspected. The echocardiogram can show if blood flow through one or more valves is abnormal or restricted.
Regardless of your current health status or symptoms, it’s always a good idea to talk about any screenings your doctor recommends. This is particularly true with stress tests, because there is more than one type and because there are circumstances under which other screenings may be more appropriate.