Like the thallium scan, the sestamibi or tetrofosmin scan shows how well supplied with blood and your heart is. Sestamibi (Cardiolite) and tetrofosmin (Myoview) refer to the type of radioactive isotope (Tc-99m sestamibi or Tc-99m-tetrofosmin) used in this test to make the flow of blood visible. Thallium, sestamibi and tetrofosmin stress tests are more accurate and informative than a standard exercise stress test.

For the sestamibi or tetrofosmin test, you will be connected to an electrocardiogram. You will be asked to exercise as hard as you can on a treadmill. When you are at peak exercise, a small amount of sestamibi or tetrofosmin will be injecting into your vein, where it will travel in the blood stream through the coronary arteries and will be taken up into the heart muscle.

If your doctor thinks that exercise is appropriate for you, you will be given a drug that increases the blood flow to through your heart arteries, mimicking what happens during exercise (pharmacologic stress).

After the stress injection, you will lie down on a special table under a camera, which obtains an image of your heart muscle blood flow. Either before or after the stress portion of the test, a rest scan is performed, usually with a separate injection of the radioisotope at rest.

The entire test takes up to four hours. At some point, you may be given a long break for lunch or a snack. Because you are not sedated, you will be able to drive yourself home after the test.