Pharmacological Nuclear Stress Test

What is a pharmacological nuclear stress test?

A pharmacological nuclear stress test is an imaging test healthcare providers use to see how blood flows to your heart. It’s also known as cardiac pharmacologic nuclear stress testing or a chemically induced stress test. The information your provider learns from the test can help them diagnose certain heart issues and recommend treatments.

Who performs a pharmacological nuclear stress test?

A provider with experience in nuclear medicine imaging performs pharmacological nuclear stress tests.

Why do healthcare providers perform a pharmacological nuclear stress test?

Your provider may order a pharmacological nuclear stress test to see if you have:

• Angina.
• Cardiovascular disease.
• Cardiomyopathy.
• Coronary artery disease.
• Damage to your heart from chemotherapy or radiation therapy.

Your healthcare provider may also want you to have this test if you recently had a heart attack (myocardial infarction).

How does a pharmacological nuclear stress test work?

There are two parts to this test, during which providers take two sets of images. During a pharmacological nuclear stress test, healthcare providers:

1. Inject a radiotracer into a vein in your arm or hand.
2. Take one set of images to determine how your heart’s blood vessels function at rest.
3. Give you a medication to dilate the blood vessels in your heart and increase your blood flow as if you were exercising.
4. Take another set of images to see how your heart and blood vessels function under stress.

How do I prepare for a pharmacological nuclear stress test?

Follow your healthcare provider’s instructions carefully. Tell your provider about any medications and herbal supplements you take. Before the test, your provider will tell you if you should take your medications or change your medication dosage. They may give you specific guidelines about medications:

• For asthma.
• For diabetes.
• That contain caffeine.

Should I take my heart medications before a pharmacological nuclear stress test?

If you take heart medications, your provider may tell you to stop taking them before the test. Don’t stop taking any medications unless your provider tells you to stop. Ask your provider any questions you have about taking medications before your test.

What should I expect on the day of the pharmacological nuclear stress test?

Follow your provider’s instructions carefully. You’ll need to avoid:

• Drinking or eating foods with caffeine (including decaffeinated drinks) in the 24 hours before the test.
• Smoking.

What should I expect during the first part of a pharmacological nuclear stress test?

During the first part of the test, providers take “resting” images of your heart and blood flow. A healthcare provider inserts a thin, flexible tube into your vein (IV catheter). They inject the radiotracer and wait about 30 minutes. Then:

• You lie still on the exam table for about 20 minutes while your provider takes images that show blood flow through your heart.
• Your provider places electrodes on your chest to monitor your heart with an electrocardiogram (EKG).

What should I expect during the second part of a pharmacological nuclear stress test?

During this part of the test, providers take images of your heart and blood flow under stress. Your provider injects medication into the IV to dilate your blood vessels. Your provider may ask you to walk slowly on a treadmill if you can. If you can’t exercise, you stay on the exam table.

After 30 minutes, you lie still for another 20 minutes. Providers take more images to see blood flow in your heart while your heart is under cardiac stress. Throughout the test, providers monitor your:

• Blood pressure.
• EKG.
• Heartbeat.

How long does a chemically induced stress test take?

A chemically induced stress test typically takes about three to four hours. But some people may have the test over two days. Talk to your healthcare provider about which approach is right for you.

What should I expect after a pharmacological nuclear stress test?

You stay in the test room while your heartbeat returns to normal. Your healthcare provider monitors your blood pressure, EKG and heart rate.

Your provider may tell you not to take certain medications for a while after your test. Follow these instructions carefully.

Is a pharmacological stress test safe?

Pharmacological nuclear stress tests are typically safe. You may have a headache or feel flushed during your test. Some people may experience a fast heart rate (tachycardia). If this happens, your provider may give you medication to regulate your heartbeat.

The radiotracer causes some radiation to stay in your body for a little while. You should:

• Avoid holding babies or small children for the rest of the day.
• Drink water to help flush the substance from your body.

Does a pharmacological nuclear stress test cause side effects?

Some medications you receive during a pharmacological nuclear stress test may cause side effects like:

• Chest pain.
• Dizziness.
• Headache.
• Low blood pressure (hypotension).
• Nausea.
• Shortness of breath (dyspnea).

What does a pharmacological nuclear stress test show? What do the results mean?

The test shows if blood flow to your heart is normal. It also shows if certain parts of your heart aren’t getting enough blood at rest or during exercise (under stress). Your provider uses this information to:

• Diagnose blood vessel and heart blockages.
• Recommend a treatment plan (if needed).

When will I know the results of the pharmacological nuclear stress test?

Healthcare providers review the images of your heart at rest and under stress. Your provider will talk with you about these images and any next steps.

When should I call my provider after a pharmacological nuclear stress test?

Let your provider know if you experience any changes in your heart rhythm.

Are a nuclear stress test and a pharmacological stress test the same?

Not necessarily. There are different types of pharmacological stress tests — nuclear and non-nuclear. With nuclear stress tests, your provider uses a radioactive substance (radiotracer) to make your heart and blood vessels visible during imaging. With a non-nuclear stress test, your provider won’t use the radiotracer.

Providers take two sets of images: one when your heart is at rest and one when it’s under stress (during exercise). However, if you can’t exercise, providers give you medicine to simulate the results of exercise on your heart.

A note from Cleveland Clinic

Healthcare providers use a pharmacological nuclear stress test to diagnose coronary artery disease and determine your risk of heart attack. Once you complete the test, you’re one step closer to getting more information about your heart. Your provider will talk with you about your test results and any treatment you may need to help keep your heart healthy.