Nuclear Exercise Treadmill test.
What is a nuclear exercise stress test?
A nuclear exercise stress test is a diagnostic test used to evaluate blood flow to the heart, and heart function during exercise. During the test, a small amount of radioactive tracer is injected into a vein. A special camera, called a nuclear gamma camera, detects the radiation released by the tracer and produces computerized images of the heart.
Combined with exercise, the nuclear heart scan can measure the blood flow patterns to the heart, and the function of the heart, at rest and during exercise.
Can I eat or drink on the day of the test?
- Yes. However, DO NOT eat or drink anything for 4 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, sodas, Mountain Dew, and chocolate products.
- Also avoid decaffeinated or caffeine-free products for 24 hours before the test because these products contain small amounts of caffeine which can interfere with the test.
- DO NOT SMOKE ON THE DAY OF THE TEST as nicotine can interfere with the test.
Should I take my medications the day of the test?
Please bring a list of all of your medications, including over-the-counter medications and supplements, to the appointment.
Please follow these guidelines about taking your medications the day of the test.
Medications with caffeine: DO NOT take any over-the-counter medications that contain 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 bring your asthma inhalers to the test.
If you have diabetes: If you take insulin to control your blood sugar, ask your physician how much insulin to take on 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 4 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 them when the test is done. Do not take your diabetes medication and skip a meal before the test.
If you have a glucose monitor, bring it with you to check your blood sugar before and after your test. If you think your blood sugar is low, tell the lab staff 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 (such as: Dilatrate, Isordil)
- Isosorbide mononitrate (such as: Imdur, ISMO, Monoket)
- Nitroglycerin (such as: Minitran, Nitropatches, Nitrostat)
- Dipyridamole (Persantine): Stop taking 48 hours before the test
- Beta Blockers (such as: metoprolol,Toprol XL, atenolol, carvedilol, Coreg, nadolol, propranolol)
Your physician may ask you to stop taking other heart medications on the day of your test. If you have questions about your medications, ask your physician. Do not discontinue any medication without first discussing with your physician.
What should I wear for the test?
Please wear comfortable clothes and shoes suitable for walking/jogging during the test.
What to expect during the test
Your test will be supervised by a physician.
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 30 minutes before the first set of "rest" images are taken.
For the imaging, you will be asked to lie very still under the gamma camera with both arms above your head, for about 15- 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 ECG.
You will start walking on a treadmill. At 3 minute intervals, the exercise workload is increased as you walk faster uphill, until you reach your target heart rate or develop any symptoms. While your heart is working hard, a second dose of radioactive tracer is given in the IV. Your heart rate, ECG, and blood pressure are monitored throughout the test. If you are unable to achieve your target heart rate, a medication may be given to simulate exercise.
About 10-20 minutes after exercising, you will again lie still under the camera with both arms over your head for about 15-20 minutes. The camera records images showing the blood flow through your heart during exercise. These images are compared to the first set.
How long will the test last?
The total appointment time takes about 4 hours. The actual exercise part of the test lasts about 6-12 minutes.
If you weigh over 300 pounds, your test may be scheduled as a two-day test.
How do I get the results of my test?
Your test is read by a cardiologist who is board-certified in Nuclear Cardiology, and then your physician will review the results and discuss them with you.
