Diagnostics & Testing

Pharmacological Nuclear Stress Test

What is a pharmacological nuclear stress test?

A pharmacological nuclear stress test is a test used to check the blood flow to your heart. During the test, a small amount of radioactive tracer is injected into a vein. A special camera, called a gamma camera, detects the radiation released by the tracer to create computer images of your heart.

You will also receive a special medication during the test. The medication widens the blood vessels that lead to your heart. The medication simulates the effect of exercise and lets your doctor compare the blood flow to your heart while you are resting and active.

Can I eat or drink on the day of the test?

DO NOT eat or drink anything for 4 hours before the test. If you need to take medications, drink only small sips of water to help you swallow your pills.
Avoid all products containing caffeine for 24 hours before the test. This includes coffee, tea, cola, Mountain Dew and chocolate.
Avoid products labeled decaffeinated and caffeine-free for 24 hours before the test. These products still contain very small amounts of caffeine.

Should I take my medications the day of the test?

Please bring a list of all of your medications with you. The list should include everything you take on a regular basis, including over-the-counter medications and vitamins/supplements.

Please follow these guidelines about taking your medications the day of the test:

DO NOT take over-the-counter medications with caffeine for 24 hours before your test. These include medications like Excedrin, Anacin, diet pills and No Doz. If you have any questions about any medication, ask your doctor, pharmacist or nurse.
If you have asthma: DO NOT take theophylline (Theo-dur) for 48 hours before your test. Please bring your asthma inhaler medication with you.
If you have diabetes: If you take insulin, ask your doctor how much insulin you should take the day of the test. You may need to only take half of your usual morning dose and eat a light meal 4 hours before the test. If you take pills to control your blood sugar, do not take your medication until after the test. Bring your diabetes medications with you. Do not take your diabetes medication and skip a meal before the test. Plan to eat and take your medication after your test.

If you have a glucose monitor, bring it with you to check your blood sugar levels before and after your test. If you think your blood sugar is low, let us know right away.

If you take heart medications: DO NOT take the following heart medications on the day of the test unless your doctor tells you to, or if you have chest pain on the day of the test and need to take the medication for relief:

Isosorbide dinitrate (Dilatrate®, Isordil®)
Isosorbide mononitrate (Imdur®, ISMO®, Monoket®)
Nitroglycerin (Minitran®, Nitropatches®, Nitrostat®)
Dipyridamole (Persantine®) - Stop taking 48 hours before the test

Your doctor may tell you to stop taking other heart medications on the day of your test. If you have any questions about your medications, ask your doctor, pharmacist or nurse. Do not stop taking any medication until after you check with your doctor.

What to expect during the test

The testing area is supervised by a doctor.

A nuclear medicine technologist will place an IV into a vein in your arm or hand and inject a small amount of radioactive tracer. The tracer is not a dye or contrast. You will wait about 20 minutes before the first set of resting images are taken.

It takes about 15 to 20 minutes to take the images.

While they are taken, you will lie very still under the gamma camera with both arms above your head. The camera will record images that show blood flow through your heart.

Next, a technician will place electrodes on your chest. These are used to record your heart's electrical activity (an electrocardiograph/EKG).

A technician will explain the possible side effects of the medication you will get through your IV. The medication widens the blood vessels to your heart to mimic the effects of exercise.

If you can, you will slowly walk on a treadmill while you receive the medication. If you cannot walk on the treadmill, you will lie on the exam table throughout the test.

Your heart rate, EKG and blood pressure will be monitored throughout the test.

Another set of images is taken about 45 minutes after you get the medication. Your doctor will compare these pictures with the ones taken at the start of the test to see differences in blood flow (resting vs. active).

How long will the test take?

The appointment will take about 2½ to 3 hours. The first part of the appointment lasts about 1½ hours. The second part of the appointment takes about 2 hours.