What is a Nuclear Stress Test?

A nuclear stress test, also known as myocardial perfusion imaging, is a test that shows how well the heart is working. Myocardium is a fancy word for the heart muscle, and perfusion means to flow through. So, this diagnostic test shows how much blood is flowing through your heart muscle. This test can tell a doctor if you have narrowed or blocked arteries, show scar tissue from a previous heart attack, assess damage after a heart attack, or show how well a procedure (such as a stent) is working. This test is also known by different names, such as a cardiac perfusion scan or thallium scan.

To perform the test, technicians will take pictures of the blood flowing through your heart using radioactive tracers that let your blood show up on a special camera. The level of radioactivity is very low. Usually, the technicians will first take pictures of your heart at rest. You may need to lay down on a table with your arms up while a machine (similar to an x-ray machine) takes a picture of your chest. Then, the technicians will want to get your heart pumping so that they can be sure to see how blood flows to all areas of the muscle. You will get electrodes placed on your body to measure your heartbeat and a cuff on your arm to measure your blood pressure. An IV will be placed in your arm. Then, you will be asked to run on a treadmill or ride a stationary bike. If you are unable to exercise, medication will be given to you through the IV to make your heart beat fast. After you have exercised enough to make your heart beat quickly, the radioactive tracers will be put into your blood through the IV. Then a second set of pictures will be taken of your heart.