Nuclear Chemical Stress Test
(myocardial perfusion imaging test)


A Nuclear Chemical Stress Test is a 2 day test that uses a radioactive imaging agent (not a dye) in conjunction with a medication to artificially simulate exercise when a patient is unable to walk on a treadmill.  The imaging agent gives off a small amount of radiation, which can be detected by a special nuclear camera called a gamma camera, and can produce pictures of the heart muscle.  The amount of radiation exposure during this test is very small and poses no health risk.  The test will help your doctor determine if there are areas of your heart muscle, which do not receive enough blood supply due to coronary artery disease.  Areas of your heart, which may have been damaged from a pervious heart attack, may also be seen.

The test is used to:

Determine if there is adequate blood flow to the heart during activity

Preparing for the test

  • Eating restrictions:
    • 10 Hours prior:  No food for ten hours prior to the test.
    • You may have unlimited amounts of fluids, however you must avoid any drinks or medications that contain caffeine, i.e. coffee, tea, chocolate, soft drinks and even decaffeinated products.
  • You may take your regular medications with water, including your blood pressure medicine.
  • Do not smoke on the day of the test, as nicotine will interfere with the results of your test.
  • Wear two-piece clothing.  No shirts with metal snaps
  • If you have asthma, COPD, emphysema or any breathing conditions, or if you use inhalers, please inform the clinical staff when scheduling the test.
  • If you are diabetic, please contact your primary care physician for instructions on adjusting your diabetic medications while you are fasting.
  • If you are allergic to Xanthenes (Theophylline or Aminophylline) we are unable to perform this test.
  • You are required to lie flat on your back with both arms above your head (elbows above the ear level) for approximately 20 minutes.  While being imaged you are not permitted to move, talk, or sleep.
  • If you are claustrophobic, we are unable to perform this test.  You will be under the nuclear camera for approximately 20 minutes.

What to expect during the test
Day 1 (Stress Portion - takes approximate 1 ½ - 2 hours)

  • Your test will take place in Nuclear Medicine. The testing area is supervised by a physician.
  • A nuclear medicine technologist will place an IV into a vein in your arm or hand that will be used to inject the radioactive tracer and chemical stress agent directly into your bloodstream.
  • The technologist will obtain a blood pressure and then attach electrodes with adhesive pads to the skin of your chest, arms and legs. Men may have chest hair shaved to allow a better connection.  The electrodes will be used to connect you to an ECG which will continuously monitor your heart throughout the test.
  • The physician will arrive and the test will begin. 
  • A small amount of radioactive tracer along with the medication to chemically stress your heart will be slowly injected through the IV for 5 ½ minutes. The tracer is not a dye or contrast.  Side effects of the infusion are shortness of breath, flushing, head pressure and chest pressure.   Each patient is different and may feel one, none or all of them.  This is normal and the physician will stay in the room until the side effects subside which takes approximately 2 minutes.
  • During the medication infusion, your blood pressure, heart rate, rhythm and ECG will be continuously monitored for any changes.
  • You will have a 45 – 60 minute break and you may eat and drink without restriction during this time.
  • Next, you will return to the Nuclear Medicine laboratory and be asked to drink approximately 16 ounces of water.  This flushes the excess radiation from the stomach or bowel and allows for cleaner images.
  • You will be asked to lie very still under the camera with both arms over your head for about 12-20 minutes (actual time spent will be relative to your height and weight). The camera will record images that show blood flow through your heart during cardiac stress/activity.
  • The nuclear technologist will process the images which takes approximately 5-10 minutes and then you will be free to go.

Day 2 (Rest Portion – takes approximately 1 ½ hours)

  • There are no special preparations or restrictions for this portion of the test.  You are able to drink and eat normally.
  • You will return to the Nuclear Medicine Department where you will receive an injection of the same radioactive imaging substance as on the first day of the study, but you will not be given the chemical stress agent.
  • You will have a 45 – 60 minute break and you may eat and drink without restriction during this time.
  • Next, you will return to the Nuclear Medicine laboratory and be asked to drink approximately 16 ounces of water.  This flushes the excess radiation from the stomach or bowel and allows for cleaner images.
  • You will be asked to lie very still under the camera with both arms over your head for about 12-20 minutes (actual time spent will be relative to your height and weight). The camera will record images that show blood flow through your heart during cardiac stress/activity.

What to expect after the test

After the nuclear cardiologist reviews your test, the results will go into your electronic medical record. Your referring physician should receive the results within 7-10 days.