Nuclear Cardiology (Nuclear Stress Test)

A nuclear stress test uses radioactive material and imaging to show how well your blood flows through your heart while at rest or under stress through exercise.

The experts at UPMC use state-of-the-art nuclear stress test technology, including the advanced D-SPECT® nuclear cardiology camera, to deliver accurate results, develop individual treatment plans, and provide ongoing care to patients with a range of heart conditions.

What Is a Nuclear Stress Test?

A nuclear stress test — also known as nuclear cardiac imaging — measures blood flow to the heart at rest and after activity. A small amount of radioactive material is injected into your arm, and a special camera scans your heart.

It's one of the most common tests doctors at UPMC use to diagnose many cardiovascular conditions.

Types of nuclear cardiology tests

There are a few variations of nuclear stress tests, including walking on the treadmill for people who can tolerate exercise and pharmacologic (medicine) agents to stress the heart for people with little or no exercise tolerance.

D-SPECT® nuclear cardiology technology

UPMC experts use the D-SPECT® nuclear cardiology camera, which offers many benefits over conventional nuclear cardiac imaging. Benefits include:

Patient comfort

• Allows you to sit upright in a chair with your arms down while the technician brings the imaging machine to your chest and scans your heart.
• This helps you feel more at ease during the test. Because you're more comfortable, you're less likely to move and disturb the images.

Faster, safer imaging

• Reduces scanning time.
• Uses less radiation.

Accurate results

• Creates high-resolution 3D images that can rotate to show every angle of the heart chamber.

Multi-Gated Acquisition (MUGA) scan

Nuclear studies include a Multi-Gated Acquisition Scan (MUGA) scan. A MUGA scan is performed using an IV injection and a gamma camera. A resting MUGA scan is a nuclear scan to evaluate how well the heart walls move and how well the heart pumps while you are at rest.

Most MUGA scans take approximately one hour and follow a specific procedure:

• Your technologist will talk with you to ensure you followed your prep instructions and can safely have the test.
• Your technologist will place an IV in your hand or arm.
• Your technologist will draw a small amount of blood to be mixed with a radioisotope.
• You will wait about 20 minutes while the blood is mixed with the radioisotope.
• You will receive an injection of your blood and the radioisotope, and your technologist will use a gamma camera to take resting images of your heart. Your heart rate will be monitored during the scan. The images generally take about 30 minutes.
• A cardiologist will review your results, and you can resume normal activities.

Conditions we diagnose with nuclear cardiology

• Coronary artery disease.
• Heart failure.
• Heart attack.
• Valve disease.
• Congenital abnormalities.

Why Would I Need a Nuclear Stress Test?

You may be given a nuclear stress test if your doctor suspects you have coronary artery disease or another heart problem, including:

• Abnormal cardiac blood work.
• Chest pain.
• History of coronary artery disease (CAD).
• Hypertension (high blood pressure).
• Shortness of breath.

Your doctor may also recommend a nuclear stress test to determine whether you have viable cardiac tissue (viability exam) or learn about your cardiac health prior to surgery.

What Are the Risks and Complications of a Nuclear Stress Test?

A nuclear stress test is generally safe, but like any medical procedure, it can have risks. These may include:

• An abnormal heart rhythm, or arrhythmia, caused by exercise or the medicine given during the test that usually goes away when the test is over.
• Chest pain during the test.
• In rare cases, a heart attack.
• In extremely rare cases, an allergic reaction to the radioactive tracer.

What Should I Expect from a Nuclear Stress Test?

Before: How to prepare for a nuclear stress test

Tell your doctor about all of the medicines you take and ask if you should make any changes to your medicines or to your diet before the test. You will receive instructions before your scheduled nuclear stress test, including:

• You may be told not to eat anything for several hours before the test.
• You may be told not to have any nicotine or caffeine products for 24 hours before the test.
• Wear comfortable clothing and walking shoes.
• Do not use powders or lotions on your chest area on your test day.
• Bring all of the medicines you take with you to the test.
• Tell your doctor if there is a chance you could be pregnant.

How long does a nuclear stress test take?

Typically, your appointment will take 2 to 4 hours. Some of this time is spent preparing for the test and waiting for your heart to absorb the tracer.

The time required for performing the stress test and acquiring the images is about an hour, but the actual exercise portion of the test will take 7 to 12 minutes. In some cases, the testing may be broken up into two days.

During your nuclear stress test

There are three main steps to a nuclear stress test:

Step One:

• Your technologist will talk to you to ensure you followed your prep instructions and can safely have the test.
• Your technologist injects a tracer (a small amount of an FDA-approved radioactive substance) into your bloodstream through an IV started in a vein in your arm.
• Your technologist will scan your heart while you're at rest to show how much of the tracer is taken up by the heart. This tells your doctor about the blood supply to your heart.

Step Two:

• You will walk on a treadmill to increase your heart rate.
• If you aren't able to exercise, you will receive medicine. This will either dilate the arteries in your heart or make your heart beat faster and harder, like it would during exercise.

Step Three:

• Your technician will give you another dose of the radioactive tracer and scan your heart a second time.

How uncomfortable is a nuclear stress test?

The exercise portion of a nuclear stress test takes 7-12 minutes. If you are unable to exercise, you may be able to receive medication that increases your heart rate.

Recovery after a nuclear stress test

After completing your test, you can resume your normal activities immediately.

How long does it take to recover from a nuclear stress test?

After a nuclear stress test, you should be able to return to your regular daily routine with no downtime.

Can I drive myself home after a nuclear stress test?

As long as you are feeling well, you should be able to drive yourself home after a nuclear stress test.

When to call your doctor about nuclear stress test complications

You should call your doctor if you experience any complications after your nuclear stress test, including:

• Abnormal heart rhythms (arrhythmias).
• Blood pressure fluctuations during or after exercise.
• Chest pain.
• Flushing sensation.
• Headache.
• Nausea.
• Rapid heart rate.
• Shortness of breath.
• Stomach pain or pressure.
• Vomiting.

What are the results of nuclear stress tests?

After the test, a doctor will read the scan. The types of information that may be obtained from your scan include whether:

• You have blockages in the heart arteries, which may be the cause of your symptoms.
• Your heart is pumping properly.
• You have had a prior heart attack.
• You have heart failure (HF).

If you have had a prior scan that is available for comparison, your doctor may be able to get information about the effects of treatment on your heart.

Results of a nuclear stress test may include:

• Normal blood flow at rest and during activity or stress — This means your heart is getting enough blood to work properly, and that major blockages in the heart arteries are unlikely.
• Normal blood flow at rest, but not during activity or stress — This means that part of your heart is not getting enough blood when you exert yourself, and you may have blocked arteries, which might be the cause of your symptoms.
• Abnormal blood flow at rest and during activity or stress — This means that you may have had a heart attack in the past from blocked arteries.

Why Choose UPMC for a Nuclear Stress Test?

The nuclear cardiology experts at UPMC have access to the most advanced nuclear stress test technology. Depending on your exam results, we will develop a customized treatment plan tailored to your unique needs. If you need additional care, our experts offer a full range of treatment options — including open and minimally invasive surgery using the latest techniques.

By UPMC Editorial Staff. Last reviewed on 2024-10-01.