Overview

A nuclear stress test is an imaging test that shows how blood goes to the heart at rest and during exercise. It uses a small amount of radioactive material, called a tracer or radiotracer. The substance is given through a vein. An imaging machine takes pictures of how the tracer moves through the heart arteries. This helps find areas of poor blood flow or damage in the heart.

A nuclear stress test is one of several types of stress tests. It may be done after a regular exercise stress test. Sometimes it is the first stress test used. If you have coronary artery disease, a nuclear stress test can help your healthcare team learn your risk of a heart attack or other heart event.

The test uses a positron emission technology (PET) scanner or single-photon emission computed tomography (SPECT) scanner.

Other names for a nuclear stress test are:

  • Cardiac PET study.
  • Cardiac SPECT study.
  • Myocardial perfusion imaging (MPI) study.

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What you can expect

A nuclear stress test uses a substance called a radioactive tracer. It's given by IV. Then the healthcare professional takes two sets of pictures of the heart — one at rest and another after exercise.

A nuclear stress test can take two or more hours. It depends on the radioactive tracer and imaging tests used.

Before

Before you have a nuclear stress tests, your healthcare professional asks questions about your medical history and how often and actively you exercise. This helps set safe limits for your exercise. Your healthcare professional also listens to your heart and lungs for anything that might affect your test results.

During

During a nuclear stress test:

  • A cuff on your arm measures your blood pressure.
  • Sticky patches on your chest, and sometimes your legs and arms, record your heartbeat.

A healthcare professional inserts a needle into one of your veins in your arm, called an IV, and injects a substance called a radiotracer. The substance also is called a radiopharmaceutical.

The substance may feel cold when it goes into your arm. It takes a few minutes for your heart cells to absorb it. Then you lie still on a table. The healthcare professional takes the first set of images of your heart.

The next part of the test often involves walking on a treadmill or riding a stationary bike. If you can't exercise, you might get medicine that increases blood flow to the heart, just as exercise does.

When your heart rate peaks from exercising, the healthcare professional gives more radiotracer thru the IV. Then the second set of images of your heart are taken. On the images, the radiotracer lights up areas of the heart that don't get enough blood flow.

You may be asked to breathe into a tube during the test. This helps determine how well you breathe during exercise.

You can stop exercising anytime you're too uncomfortable. Usually, you keep exercising until your heart rate reaches a specific goal or you get concerning symptoms. These symptoms might include:

  • An irregular heartbeat or other changes in your heartbeat.
  • Dizziness.
  • Moderate to severe chest pain.
  • Severe shortness of breath.
  • Unusually high or low blood pressure.

After

After the exercise is done, you might be asked to stand still for a few seconds and then lie down for a short while. Your healthcare professional continues to watch your heartbeat and breathing during this time.

After the test you can usually return to your usual activities unless your healthcare team tells you not to do so.

The radioactive tracer leaves the body in the urine or stool. Drink plenty of water to help flush it out of your system.

Dec. 03, 2024
  1. Cardiac nuclear medicine. American College of Radiology. https://www.radiologyinfo.org/en/info/cardinuclear. Accessed Dec. 6, 2022.
  2. Heart tests. National Heart, Lung, and Blood Institute. https://www.nhlbi.nih.gov/health/heart-tests. Accessed Dec. 6, 2022.
  3. Wolk MJ, et al. ACCF/AHA/ASE/ASNC/HFSA/HRS/SCAI/SCCT/SCMR/STS 2013 multimodality appropriate use criteria for the detection and risk assessment of stable ischemic heart disease: A report of the American College of Cardiology Foundation Appropriate Use Criteria Task Force, American Heart Association, American Society of Echocardiography, American Society of Nuclear Cardiology, Heart Failure Society of America, Heart Rhythm Society, Society for Cardiovascular Angiography and Interventions, Society of Cardiovascular Computed Tomography, Society for Cardiovascular Magnetic Resonance, and Society of Thoracic Surgeons. Journal of the American College of Cardiology. 2014; doi:10.1016/j.jacc.2013.11.009.
  4. Chareonthaitawee P, et al. Exercise ECG testing: Performing the test and determining the ECG results. https://www.uptodate.com/contents/search. Accessed Dec. 6, 2022.
  5. Werner RA, et al. The changing face of nuclear cardiology: Guiding cardiovascular care toward molecular medicine. Journal of Nuclear Medicine. 2020; doi:10.2967/jnumed.119.240440.
  6. Arruda-Olson AM, et al. Prognostic features of stress testing in patients with known or suspected coronary disease. https://www.uptodate.com/contents/search. Accessed Dec. 6, 2022.
  7. Coronary heart disease. National Heart, Lung, and Blood Institute. https://www.nhlbi.nih.gov/health/coronary-heart-disease. Accessed Dec. 6, 2022.
  8. Libby P, et al., eds. Nuclear cardiology. In: Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 12th ed. Elsevier; 2022. https://www.clinicalkey.com. Accessed Dec. 6, 2022.
  9. AskMayoExpert. Cardiac stress testing (adult). Mayo Clinic; 2022.
  10. Hendel RC, et al. ACCF/ASNC/ACR/AHA/ASE/SCCT/SCMR/SNM 2009 appropriate use criteria for cardiac radionuclide imaging: A report of the American College of Cardiology Foundation Appropriate Use Criteria Task Force, the American Society of Nuclear Cardiology, the American College of Radiology, the American Heart Association, the American Society of Echocardiography, the Society of Cardiovascular Computed Tomography, the Society for Cardiovascular Magnetic Resonance, and the Society of Nuclear Medicine. Circulation. 2009; doi:10.1161/CIRCULATIONAHA.109.192519.
  11. Single photon emission computed tomography (SPECT). American Heart Association. https://www.heart.org/en/health-topics/heart-attack/diagnosing-a-heart-attack/single-photon-emission-computed-tomography-spect. Accessed Dec. 6, 2022.
  12. Mankad R (expert opinion). Mayo Clinic. May 11, 2021.

Nuclear stress test