Nuclear Dual Isotope Stress Test
A nuclear dual isotope stress test evaluates the blood supply to your heart muscle during periods of exercise (stress) and at rest. This helps doctors determine if you have a blockage in one or more arteries of the heart.
The arteries that supply blood to the heart muscle can become clogged or narrowed from the buildup of plaque (called atherosclerosis or coronary artery disease). To examine your heart’s blood flow, we inject two safe, radioactive tracers (Thallium-201 and Technetium-99M) into your blood through an intravenous (IV) line inserted into a vein in your arm. Separate images of the tracers allow us to see the heart muscle receiving the blood supply more clearly.
What to Expect During a Nuclear Dual Isotope Stress Test
Our nuclear medicine technologist will take you to an exam room to explain the two-part procedure, including one 20-minute imaging test with your heart at rest and another 20-minute imaging test during stress. Prior to your test, we will gather your medical history and answer any questions you may have. You will also need to sign a consent form.
To begin the test, your technician will use gel to place small plastic pads on your chest. These will connect to an electrocardiogram (EKG) monitor to measure the electrical signals from your heart. For men, we may need to shave small areas to remove chest hair and ensure the pads stick. We will also take a baseline blood pressure reading.
For the first part of the test that measures your heart function at rest, we will put an IV line in your arm to give you the radioactive tracer (Thallium-201).
During the imaging session, you will lie flat on your back on a table with your left arm resting above your head. CT scan cameras will slowly move around your chest for about 20 minutes. It is very important for you to lie as still as possible during the imaging session. Normal breathing is fine.
Once the first part of the test is complete, you will have a break before the second part of the test. During this break, you can have a small low-fat meal, regular coffee (no creamer) and any other liquids.
After the break, you will have the second part of the test that measures your heart function during stress. When the nurse arrives, you will begin receiving a second radioactive tracer injection (Technetium-99M) gradually through your IV line to increase your heart rate. During this time, if you develop any discomfort, please tell the nurse immediately.
You will then lay flat on the imaging table as you did for the first test, and CT scan cameras will slowly move around your chest. It will take about 20 minutes. Again, it is very important for you to lie as still as possible during the imaging session. Normal breathing is fine.
After the stress portion of the test, we will remove the EKG pads and your IV line. You may then resume your regular diet and routine. We will send a copy of the report to your referring doctor.
How to Prepare the Day of the Nuclear Dual Isotope Stress Test
The complete process for the nuclear dual isotope stress test will take about four hours. You will have short breaks between imaging sessions. To prepare for your test, you should:
- Ask your doctor if you need to stop taking your medications, such as beta-blockers, before the test.
- Avoid food and drink four hours before your appointment. If you eat or drink, you will need to reschedule your test.
- Avoid caffeine, decaffeinated beverages or chocolate for 24 hours before your appointment. This includes coffee, tea, cocoa, soda pop and other caffeinated drinks.
- Bring or wear loose, comfortable clothing and shoes suitable for brisk walking or jogging. Avoid heels or sandals. Avoid wearing a dress, full slip or tight jeans. Wear pants or shorts and a loose-fitting top.
- Bring a list of your current medications or your medications in their bottles.
- Take any medications with sips of water unless otherwise instructed by your doctor.
- Talk to your doctor and reschedule your test if you are pregnant, may be pregnant or are a nursing mother.
Important Information About Cancelations and Rescheduling
If you need to cancel or reschedule the test, please call us at (321) 841-6444 at least 48 hours before your appointment time.
If you do not show up for your appointment, or you do not give 48 hours’ notice to cancel or reschedule, you may be charged a fee of up to $200 to cover the cost of the medications ordered for your test.
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