Thallium stress test Health Article

Alternative Names

Sestamibi stress test; MIBI stress test; Myocardial perfusion scintigraphy

Definition

Thallium stress test is a nuclear imaging method that shows how well blood flows into the heart muscle, both at rest and during activity.

How the test is performed

This test is done at a medical center. The test is done in two parts:

• Part 1: You will walk on a treadmill or be given a medicine called a vasodilator to increase your heart rate. You will be given the drug if your doctor does not think exercise is safe for you or if you have joint problems that may make doing so difficult.
• Part 2: The health care provider will inject a radioactive substance into one of your veins and then take pictures of your heart.

The radioactive material may be thallium or sestamibi. (If sestamibi is used, it's called a "sestamibi stress test.") This substance travels through your bloodstream into the heart muscle.

Next, you will be asked to lie down on a table under a special camera that scans the heart. A computer creates pictures of the heart by tracking how the radioactive material moves through the area.

The first pictures are taken shortly after you get off the treadmill or are given the vasodilator drug. These images show how blood flows to the heart during exercise. This is the part most commonly referred to as the "stress test," because it is the most challenging for your heart.

After lying quietly for a few hours, you'll have more pictures of the heart taken. These images show blood flow through your heart during rest.

The entire test can take about 4 hours. You will usually be given a long break in between scans and allowed to have caffeine-free lunch or a snack at a nearby cafeteria.