Nuclear Stress Testing

A nuclear stress test uses radioactive dye and an imaging machine to create pictures showing areas with poor blood flow or damage. The test usually involves injecting radioactive dye, then taking two sets of images—one while you're at rest and another after you exercise.

A nuclear stress test is one of several types of stress tests that may be performed alone or in combination. It can help determine your risk of a heart attack or other cardiac event if your doctor knows or suspects that you have coronary artery disease (CAD), which hinders blood flow.

Who is eligible for a nuclear stress testing?

You may need a nuclear stress test if you have symptoms like chest pain or shortness of breath. Your doctor may also recommend a nuclear stress test to guide the treatment of heart disorders. It can help your doctor find out how well treatment is working and help establish the right treatment plan for you by determining how much exercise your heart can handle.

What conditions can be diagnosed by a nuclear stress testing?

A nuclear stress test can diagnose CAD. Your coronary arteries are the major blood vessels that supply your heart with blood, oxygen, and nutrients. CAD develops when these arteries become damaged or diseased—usually due to a buildup of deposits containing cholesterol and other substances (plaques).

How do I prepare for a nuclear stress testing?

• You may be asked not to eat, drink or smoke for a period of time before a nuclear stress test. You may need to avoid caffeine the day before and the day of the test.
• Ask your doctor if it's safe for you to continue taking all of your prescription and over-the-counter medications before the test. They might interfere with certain stress tests.
• If you use an inhaler for asthma or other breathing problems, bring it to the test. Make sure your doctor and the health care team member monitoring your stress test know that you use an inhaler.
• Wear or bring comfortable clothes and walking shoes. Don't apply oil, lotion, or cream to your skin on the day of your nuclear stress test.
• A nuclear stress test may be performed in combination with an exercise stress test, in which you walk on a treadmill.
• This can take two or more hours, depending on the radioactive material and imaging tests used.

What should I expect during my nuclear stress testing?

Before you start the test, a technician inserts an intravenous (IV) line into your arm and injects a radioactive dye (radiopharmaceutical or radiotracer). The radiotracer may feel cold when it's first injected into your arm. Then, you'll lie still on a table and have your first set of images taken while your heart is at rest.

A nurse or technician will place sticky patches (electrodes) on your chest, legs, and arms. Some areas may need to be shaved to help them stick. The electrodes have wires connected to an electrocardiogram machine, which records the electrical signals that trigger your heartbeats. A cuff on your arm checks your blood pressure during the test.

You'll exercise on a treadmill or bike until either your heart rate has reached a set target or you develop symptoms like:

• Dizziness.
• Chest pain.
• An abnormal heart rhythm.
• Severe shortness of breath.
• Abnormally high or low blood pressure.
• Certain changes in your electrocardiogram.

You and your doctor will discuss your safe limits for exercise. You can stop the test anytime you're too uncomfortable to continue.

You'll have another injection of radiotracer when your heart rate peaks. About 20 to 40 minutes later, you'll lie still on a table and have a second set of images made of your heart muscle. The dye shows any areas of your heart receiving inadequate blood flow.

Your doctor will use the two sets of images to compare the blood flow through your heart while you're at rest and under stress. After you stop exercising, you might be asked to stand still for several seconds and then lie down for a period of time with the monitors in place.

When the test is complete, you may return to normal activities unless your doctor tells you otherwise. The radioactive material will naturally leave your body in your urine or stool.

Why choose Presbyterian for nuclear stress testing?

Presbyterian Heart and Vascular Care has a skilled vascular care team who can provide a wide range of services from diagnosis to treatment. Their surgeons are trained in many different techniques and procedures, many of which can provide you with a shorter recovery period and less hospital time.