Nuclear stress test
Nuclear stress test
A nuclear stress test measures blood flow to your heart muscle both at rest and during stress on the heart. It's performed similar to a routine exercise stress test, but provides images that can show areas of low blood flow through the heart and areas of damaged heart muscle.
A nuclear stress test usually involves taking two sets of images of your heart — one set during an exercise stress test while you're exercising on a treadmill or stationary bike, or with medication that stresses your heart, and another while you're at rest. A nuclear stress test is used to gather information about how well your heart works during physical activity and at rest.
You may be given a nuclear stress test if your doctor suspects you have coronary artery disease or another heart problem, or if an exercise stress test alone wasn't enough to pinpoint the cause of symptoms like chest pain or shortness of breath. A nuclear stress test may also be recommended in order to guide your treatment if you've already been diagnosed with a heart condition.
Why it's done
Your doctor may recommend a nuclear stress test to:
A nuclear stress test is generally safe and complications are rare. But, as with any medical procedure, it does carry a risk of complications.
Potential complications include:
How you prepare
You may be asked not to eat, drink or smoke for two hours before a nuclear stress test. You can take your medications as usual, unless your doctor tells you not to.
If you use an inhaler for asthma or other breathing problems, bring it with you 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 with you to the exercise stress test.
What you can expect
When you arrive for your nuclear stress test, your doctor asks you about your medical history and how often you typically exercise. This helps determine the amount of exercise that's appropriate for you during the stress test.
During a nuclear stress test
If you're unable to exercise, you may be injected with a medication that increases blood flow to your heart muscle — simulating exercise — for the test.
You then begin walking on the treadmill or pedaling the stationary bike slowly. As the test progresses, the speed and incline of the treadmill increases. A railing is provided on the treadmill that you can use for balance, but don't hang on to it, as that may skew the results of the test. On a stationary bike, the resistance increases as the test progresses, making it harder to pedal.
The length of the test depends on your physical fitness and symptoms. The goal is to have your heart work hard for about 8 to 12 minutes, in order to thoroughly monitor its function. You continue exercising until your heart rate has reached a set target, or until you develop symptoms that don't allow you to continue or warning signs detected by those monitoring your test, including:
You may stop the test at any time if you are too uncomfortable to continue exercising.
Injection of dye
After exercising, you'll be asked to rest for two to four hours. During this time, you shouldn't eat or drink anything, or do any strenuous activities. After this time, you'll have a second set of images taken of your heart while you lie on an examination table. Again, a technician will inject radioactive dye through an IV and will take images of your heart. This second set of images will let your doctor compare the blood flow through your heart while you're exercising and at rest.
After a nuclear stress test
Exercise stress test
In an exercise stress test, electrodes are taped to your chest to detect your heart's rhythm. A nurse or technician will watch your heartbeat on a monitor while you exercise. If your doctor orders a ...
Your doctor will discuss the results of your nuclear stress test with you. Your results could show:
If your test results show you don't have enough blood flow through your heart, you may need to undergo coronary angiography — a test to look directly at the blood vessels supplying your heart. If you have severe blockages you may need a coronary intervention (balloon angioplasty and stent placement) or open heart surgery (coronary artery bypass).
Last Updated: 2009-12-15
© 1998-2013 Mayo Foundation for Medical Education and Research (MFMER). All rights reserved. A single copy of these materials may be reprinted for noncommercial personal use only. "Mayo," "Mayo Clinic," "MayoClinic.com," "Mayo Clinic Health Information," "Reliable information for a healthier life" and the triple-shield Mayo logo are trademarks of Mayo Foundation for Medical Education and Research.
Terms and conditions of use