Key Points

• A stress test helps show whether enough blood flows to your heart when it's working hard. Doctors usually use stress testing to help them diagnose coronary artery disease (CAD) or to see how serious this disease is in those who are known to have it.
• During a stress test, your heart is monitored using images or through dime-sized electrodes attached to your chest, arms, or legs. You may be asked to breathe into a special tube during the test. This will allow your doctor to see how well you're breathing.
• Standard exercise stress tests use EKGs (electrocardiograms) and breathing and blood pressure monitoring to assess blood flow in the heart. Imaging stress tests, such as those that use echocardiography, radioactive dyes, or magnetic resonance imaging (MRI), show how well blood is flowing in heart muscle. Imaging stress tests tend to be more accurate than standard exercise tests.
• You may need a stress test if you have CAD symptoms, such as chest pain and shortness of breath. If you've been diagnosed with CAD or recently had a heart attack, you may have stress testing to see whether treatments aimed at improving blood flow in the heart's arteries are needed and likely to help you. Stress testing also is done on people who have signs of an arrhythmia (irregular heartbeat).
• Stress testing may be done at a doctor's office or at a hospital. It will usually take between 1 and 3 hours.
• You may have to restrict your diet or not take certain medicines before a stress test. Be sure to wear shoes in which you can exercise comfortably during the stress test.
• Your health status will always be closely monitored during a stress test, and you will not have to exercise more than you think you can handle. Stress tests are safe and have few side effects. The chance of a stress test causing a heart attack or death is only about 1 in 5,000.
• You're able to return to all your normal activities after a stress test.
• If test results are normal, no further testing or treatment is usually needed unless your CAD symptoms persist. If there are abnormal results on your standard exercise stress test, your doctor will probably want you to have an imaging stress test or undergo other testing. But imaging may not be needed if factors other than CAD could explain the abnormal results. Abnormal results on an imaging stress test will require more testing and/or treatment.