Medical Health Encyclopedia

Thallium and sestamibi stress tests

Then you will need to lie quietly for 2-3 hours, and at that point the scanner will make another series of pictures of your heart. These images will show the circulation of blood through your heart muscle at rest.

If your doctor has indicated that your test should be performed without exertion, then at the beginning of the test you will not exercise, but instead will receive an intravenous medication, a vasodilator (usually dipyridamole or adenosine). This medication will selectively dilate (widen) the coronary arteries as long as they are normal; arteries with blockages will receive less blood flow and will be less dilated, allowing less blood flow into the heart muscle. After this initial medication, you will receive the injection with the radiotracer. The test done using a vasodilator can potentially show a defect in the same way as the test with exercise does.

How to prepare for the test:

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You will be instructed to wear comfortable clothes and shoes with non-skid soles. You will probably be asked not to eat or drink anything after midnight, except for a few sips of water if you need to take medicines.

For one entire day prior to the test, you will be required to abstain from caffeine and certain medications. Caffeine is in food and beverages such as all regular and decaffeinated coffees or teas, chocolate products, many sodas, and certain pain relievers. These are just a few examples. Please read the labels of your food and beverages carefully, because caffeine consumed before the test may invalidate the test results.

Medications that you may need to stop taking before the test include some asthma medicines and medicines for chest pain (angina); check with your doctor. If you take insulin to control your blood sugar, ask your physician if or how much insulin you should take the day of the test.