What is a cardiac PET study?
A PET study 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 simulates exercise for patients unable to exercise on a treadmill or stationary cycle.
The test is also used to:
- Evaluate the amount of damage to your heart after a heart attack
- Evaluate the effectiveness of your cardiac treatment plan
Can I eat or drink on the day of the test?
- Yes. However, DO NOT eat or drink anything except water after midnight the evening before the test.
- Avoid all products that contain caffeine for 24 hours before the test. In general, caffeine is found in coffee, tea, colas and other soft drinks, most chocolate products, as well as strawberries (these contain a small amount of caffeine), as caffeine will interfere with the results of the test. 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, as 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 NoDoz®) 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 medication to the test.
If you have diabetes: If you take insulin to control your blood sugar, ask your physician how much insulin you should take the day of the test. Your physician may tell you to take only half of your usual morning dose and to eat a light meal four hours before the test. 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, bring it with you to check your blood sugar levels before and after your test. 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 (for example: Dilatrate®, Isordil®)
- Isosorbide mononitrate (for example: Imdur®, ISMO®, Monoket®)
- Nitroglycerin (for example: Minitran®, Nitropatches®, Nitrostat®)
- Dipyridamole (Persantine®) -- 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 to expect during the test
- Your test will take place in Nuclear Medicine. The testing area is supervised by a physician.
- You will be given a hospital gown to wear. You’ll be asked to remove your clothing from the waist up.
- The healthcare provider will place 10 electrodes (small, flat, sticky patches) on your chest. The electrodes are attached to an electrocardiograph (EKG) monitor that charts your heart’s electrical activity during the test.
- The healthcare provider will place an IV into a vein in your arm or hand.
- A resting EKG will be performed, and your heart rate and blood pressure will be recorded.
- You will be asked to lie very still on the exam table under a camera.
- A small amount of radioactive tracer, such as rubidium, will be injected into your IV. The tracer is not a dye or contrast. After the tracer is injected, you will wait about 20 minutes before the first set of “resting” images are taken. The tracer allows the physician to view the blood flow in your heart at rest.
- A medication (e.g., dipyridamole, adenosine or regadenoson) will be injected into your IV that will cause your heart to react as if you were exercising. The medication may cause a warm, flushing feeling and in some cases, a mild headache. Please report your symptoms to the healthcare team.
- At regular intervals, the healthcare team will ask you how you are feeling. Please tell them if you feel chest, arm or jaw pain or discomfort, short of breath, dizzy, lightheaded, or if you have any other unusual symptoms.
- A small amount of tracer will again be injected into your IV to allow the physician to view the blood flow in your heart during activity.
- The IV will be removed from your arm at the end of the test.
How long will the test last?
The appointment will take approximately three to four hours.
How do I get the results of my test?
After the cardiologist reviews your test, the results will go into your electronic medical record. Your referring physician will have access to the results and will contact you to discuss them.