Cardiac Nuclear Imaging
Nuclear imaging tests help determine how well your heart is working
Most imaging tests give good information about the physical state of body structures and organs, but they do not always provide data about how well the organ is functioning. For example, the heart muscle may appear undamaged in certain types of scans, but the heart may not be pumping in a normal manner.
Nuclear imaging tests are very sensitive and can help detect how well the heart is working. One type of cardiac nuclear imaging is known as a nuclear exercise stress test. A minimal amount of radioactive tracer is injected into a vein to trace blood flow to the heart. A type of camera measures the location and amount of radiation released by the tracer while you are walking on a treadmill, and creates images that your physician can use to assess whether there is adequate blood flow to the heart during activity.
Before the procedure:
- Have nothing to eat or drink anything beginning 4 hours before the test.
- Be sure to tell your Hurley physician about any medications you are taking, including over-the-counter medicines or dietary supplements. Take your medications as directed by your Hurley physician, using only small sips of water to help swallow the pills.
- Avoid the use of caffeinated beverages (including those labeled “caffeine free” or “decaffeinated,” as they still contain trace amounts of caffeine).
- If you are a smoker, do not smoke on the day of the test.
- Wear comfortable clothes and shoes you can walk in.
- Be prepared for the test to last about two to three hours.
During the procedure:
After admission to Hurley Medical Center’s cardiac holding unit, you will be prepared for the procedure. A technologist injects the radioactive tracer into a vein through an IV line that has been placed in your arm or hand. After about 20 minutes, you will be asked to lie very still under the camera with both arms above your head. In order for the camera to record accurate images of the blood flow through your heart during rest, you may be asked to lie still in this position for about 15 to 20 minutes.
Electrodes will then be placed on your chest to monitor electrical activity in your heart. You will be asked to walk on a treadmill for about ten minutes, increasing your pace by small amounts until your heart is beating at the target rate. Another injection of radioactive tracer will given to you through the IV. Throughout this process, your heart rate, EKG and blood pressure will be monitored.
Some people have difficulty achieving their target heart rate. If this happens during your test, medication may be given to that opens up the blood vessels and simulates the effects of exercising.
After the exercise portion of the test is complete, you will be allowed to rest for about 30 minutes. You will then lie still under the camera in the same position as before, and a second set of images will be taken, which will be compared to the first set.
After the procedure:
You can return home and resume your normal activities. The radioactive tracer in your blood will dissipate quickly and will have no lasting effects. Your Hurley cardiologist will discuss the results of the test with your physician.