Pharmacological Nuclear Stress Test

(Also referred to as Adenosine Nuclear Stress Test)

What is a pharmacological nuclear stress test?

A pharmacological nuclear stress test is a diagnostic test used to evaluate blood flow to the 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 produce computer images of the heart. Combined with a medication, the test can help determine if there is adequate blood flow to the heart during activity versus at rest. The medication does not increase your heart rate. The medication dilates blood vessels leading into the heart, increasing blood flow, therefore simulating exercise for patients unable to exercise on a treadmill.

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

Do not eat or drink anything for 6 hours before the test. If you must 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. In general, caffeine is found in coffee, tea, colas, Mountain Dew and chocolate products. Also, avoid decaffeinated or caffeine-free products for 24 hours before the test, as these product contain trace amounts of caffeine. Do not smoke on the day of the test. Nicotine will interfere with the results of your test.

Should I take my medications the day of the test?

Please bring a copy of all of your medications, including over-the-counter medications and supplements that you routinely take, to the test appointment.

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

Medications with caffeine: DO NOT take any over-the-counter medication that contains caffeine (such as Excedrin, Anacin, diet pills and No Doz) for 24 hours before the test. Ask your physician, pharmacist or nurse if you have questions about other medications that may contain caffeine.

If you have asthma: Your physician will tell you NOT to take theophylline (Theo-dur) for 48 hours before the test. Please plan to bring your asthma inhaler mediation to the test.

If you have diabetes: If you take insulin to control your blood sugar, please take only half of your usual morning dose and to eat a light meal 6 hours before the test if your procedure is scheduled in the afternoon. If your procedure is scheduled in the morning, please do not take your insulin and do not eat any food 6 hours before your scheduled exam. If you take pills to control your blood sugar, do not take your medication until after the test is complete. Bring your diabetes medications with you so you can take it when the test is complete. Do not take your diabetes medication and skip a meal before the test. If you own a glucose monitor your may bring it with you to check your blood sugar levels before and after your test should you feel it necessary. If you think your blood sugar is low, tell the lab personnel immediately. Plan to eat and take your blood sugar medication following your test.

If you take heart medications: Do not take the following heart medications on the day of the test unless your physician tells you otherwise, or unless it is needed to treat chest discomfort the day of the test:

  • Isosorbide Dinitrate (Dilatrate, Isordil)
  • Isosorbide Mononitrate (Imdur, ISMO, Monoket)
  • Nitroglycerin (Minitran, Nitropatches, Nitrostat)
  • Dipyridamole (Persantine, Aggrenox) — Stop taking 48 hours before the test

 

Your physician may also ask you to stop taking other heart medications on the day of your test. If you have any questions about your medications, ask your physician. Do not discontinue any medication without first talking with your physician.

What should I wear for the test?

Please wear comfortable clothes, a loose button up shirt is preferred.

What should I expect during the test?

Your test will take place in the nuclear department of Golden Empire Cardiology.

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. After the tracer is injected, you will wait about one hour before the first set of “resting” images are taken. Then you will be asked to lie very still under the gamma camera with both arms above your head for about 15 to 20 minutes. The camera will record images that show blood flow through your heart at rest.

Next, a technician will place electrodes on your chest to monitor your EKG. You will start the adenosine infusion over 4 minutes. There are multiple side effects possible with the most common being shortness of breath and a headache.  Side effects will go away within 1-2 minutes after the medication is stopped. A second dose of radioactive tracer will be injected into the IV in the middle of the infusion. Your heart rate, EKG and blood pressure will be monitored throughout the test.

About one hour after the stress test, you will be asked to again lie very still under the camera with both arms over your head for about 15-20 minutes. The camera will record images that show blood flow through your heart during exercise. These images will be compared to the first set. It is during this waiting period that you will be able to eat something.  You may bring a snack to eat here during this waiting period or you may be able to leave for a short period of time to get something to eat.

How long will the test last?

The appointment will take about 3 hours. If you weigh over 250 pounds, your test may be scheduled as a two-day test.

How do I get the results of my test?

The results will be sent to your referring physician usually within 48 hours.

What should I do if I need to cancel my scheduled test?

We ask that you call 24 hours in advance to cancel a scheduled nuclear examination to avoid charges to your account for unused pharmaceuticals.

May I bring a family member or friend with me?

During the testing portion of the examination you will be brought back to the nuclear department.  Your family or friends will be required to wait in the main lobby during the procedure.

The above information was adapted from The Cleveland Clinic Website.