What is a Nuclear Cardiac Stress Test?

This test provides valuable information about your coronary arteries and heart muscle and is sometimes called a myocardial perfusion study. It is used to evaluate symptoms that may be caused by blockages in the arteries that supply oxygen-rich blood to your heart muscle. Pictures are taken of your heart using a radioactive medicine. Each set of pictures is compared to see if blockages exist in your coronary arteries.

Indications

Your physician may order this exam to evaluate the following symptoms:

• Chest pain, pressure or heaviness
• Shortness of breath
• Pain or pressure in the neck or jaws
• Back pain or left arm pain
• Palpitations

 

How do I prepare for the procedure?

Please follow the instructions below to prepare for your test. If these instructions are not followed, your appointment will be rescheduled.

• Do not consume caffeine for 12 hours before your test. This includes all coffee, tea, decaffeinated drinks, soft drinks, energy drinks or water enhancers, chocolate in any form, or medication containing caffeine.
  
• Do not eat for 2 hours prior to the test unless you have diabetes. If you have diabetes, you may eat a light breakfast and take your insulin as usual.
• Do not take any medications that are Dipyripdamole (Persantine) or Adenosine based for 48 hours prior to your nuclear stress test. Please check with your pharmacist or physician.
• Do shower or bathe the morning of your stress test, but do not apply lotion or powder to your chest.
• Do wear comfortable two-piece attire and comfortable walking shoes.
  

What can I expect during the test?

Nuclear stress test with exercise:
A nuclear stress test with exercise is used to determine what areas of the heart muscle have decreased blood flow during exercise. This test is done by first injecting a radionuclide through an intravenous catheter into a vein in the arm or hand while the patient is at rest. After the radionuclide has been injected and has circulated through the blood stream, a special machine called a gamma camera takes pictures of the heart while the person lies still on a table. This scanning usually lasts about 10 minutes. This is the rest scan of the heart.

Next, the exercise stress test is performed with the patient walking on a treadmill. At peak exercise, a second radionuclide dose is injected through the intravenous catheter. After the radionuclide has been injected and has circulated through the blood stream, a second scan of the heart is performed in the gamma camera. This scanning also lasts about 10 minutes. This is the stress scan of the heart. 

Pharmacological (chemical) stress test:
A pharmacologic stress test is used when the physician has determined that exercise on a treadmill is not an appropriate choice due to the patient's medical or physical condition. In this situation, medications are given that cause the coronary arteries to dilate. This pharmacologic response is similar to the response caused by exercise. This test is done by first injecting a radionuclide through an intravenous catheter into a vein in the arm or hand while the patient is at rest. After the radionuclide has been injected and has circulated through the blood stream, a special machine called a gamma camera takes pictures of the heart while the person lies still on a table. This scanning usually lasts about 10 minutes. This is the rest scan of the heart.

Next, the pharmacologic stress test is performed with the patient receiving the medication. At peak stress, a second radionuclide dose is injected through the intravenous catheter. After the radionuclide has been injected and has circulated through the blood stream, a second scan of the heart is performed in the gamma camera. This scanning also lasts about 10 minutes. This is the stress scan of the heart.

How long does the 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.