What is the Nuclear Stress test?

The nuclear stress test is one of several stress tests that may be performed alone or combined with an exercise stress test. The Nuclear Stress test uses radioactive dye and an imaging machine to produce pictures that show the poor blood flow or damage in your heart.

The difference between a nuclear stress test and an exercise stress test is that nuclear stress test helps better determine the risk of a heart attack or other cardiac event.

Why is the Nuclear Stress test perform?

If a routine stress test did not detect the cause of chest pain or shortness of breath. Also, a nuclear stress test is performed to guide treatment if you are diagnosed with any heart condition, including:

  • Diagnose coronary artery disease
  • Chest pain or shortness of breath
  • Guide treatment of heart disorders


Complications are rare. A nuclear stress test is safe, and as with any medical procedure, there is a risk of complications, including:

  • Allergic reaction
  • Abnormal heart rhythms (arrhythmias)
  • Heart attack (myocardial infarction)
  • Dizziness or chest pain
  • Low blood pressure


The doctor will provide specific instructions on how to prepare for your nuclear stress test.

Food and medications: You may be asked

  • To not eat, drink or smoke for a while before a nuclear stress test.
  • Avoid caffeine the day before and the day when the procedure is performed.
  • Tell your doctor if it’s safe taking all prescribed and over-the-counter medications before the test
  • Bring to the test inhaler for asthma or other breathing problems

Clothing and personal items

  • Wear comfortable clothes
  • Do not apply oil, lotion, or cream to your skin the day of the nuclear stress test.

Depending on the radioactive material and imaging tests, the nuclear stress test can take two or more hours.

Before a nuclear stress test, your doctor will ask you some questions about your medical history and how often and strenuously you exercise. Then, the doctor will listen to your heart and lungs to detect any abnormalities that might affect your test results.

During a nuclear stress test

  • Before you start the test, a technician inserts an intravenous (IV) line into your arm and injects a radioactive dye (radiopharmaceutical or radiotracer).
  • It takes about 20 to 40 minutes for your heart to absorb the radiotracer.
  • A nurse will place a cuff on your arm to check your blood pressure during the test. Also, you may be asked to breathe into a tube during the test to show how well you can breathe during exercise.
  • A nurse will place patches (electrodes) on your chest, arms, and legs. In Some cases, certain areas may need to be shaved before the test. The electrodes will be connected to an electrocardiogram machine, which will record the electrical signals that trigger your heartbeats.

If you can not exercise, your doctor will inject a specific drug into your IV line to increase blood flow to your heart. This drug will mimic similar side effects to those caused by physical activities, such as shortness of breath. You might get a headache as well.

For an exercise stress test, you will either walk on a treadmill or ride a stationary bike. Typically you will start slowly; as the test progress, it will get more challenging as es. Avoid hang on tightly, as it may alter the results.
You will continue exercising until either your heart rate has reached a set target, develop symptoms that do not allow you to continue, or you experience the following:

  • Moderate to severe chest pain
  • Severe shortness of breath
  • Abnormally high or low blood pressure
  • An abnormal heart rhythm
  • Dizziness

You can stop the test anytime if you are too uncomfortable to continue.
Them, another 20 to 40 minutes after a second injection of radiotracer when your heart rate peaks, and the second set of images of your heart muscle will be recorded where dye areas show inadequate blood flow in your heart.
Your doctor will compare the two sets of images to evaluate the blood flow through your heart.

After a nuclear stress test

After you stop exercising, you might be asked to stand still for several seconds and lie down for a while. The doctor will be looking at the monitors to check for any abnormalities as your heart rate and breathing return to normal.

After the test is complete, you may return to your normal activities unless your doctor tells you otherwise. The doctor will advise you to drink plenty of water to flush the dye out of your system as the radioactive material will naturally leave your body through your urine or stool.

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