A thallium scan is a test that uses a radioactive substance known as a tracer to produce images of the heart muscle. The exercise thallium scan is especially useful in diagnosing coronary heart disease.
You may also be connected to a holter monitor. This is used to record your heartbeat and determine if any palpitations occur. Electrodes are placed on the chest and record your heart's electrical activities. If there are palpitations in your heartbeat, then your doctor may schedule a stress test to help determine the cause.
What Does It Show?
The exercise portion of the thallium test is usually done first.
Preparing for the Test
During imaging, the camera takes pictures of your heart at various angles.
After the initial set of pictures, you will be asked to remain relatively quiet for the next 2 to 4 hours. You may leave the test area and may be allowed limited beverages, but no solid food.
When you return, you will have additional pictures taken without repeating the exercise. These images are used for comparison.
Is the Test Safe?
The radiation exposure during a thallium scan is small and the doses used are safe. However, if you are pregnant, suspect you may be, or are a nursing mother - be sure to let your doctor know.