Before the test begins, the doctor or a technician will use a needle to insert an intravenous (IV) line into a vein in your arm. Through this IV line, he or she will put radioactive tracer into your bloodstream at the right time.

You also will have EKG (electrocardiogram) patches attached to your body to check your heart rate during the test. (An EKG is a simple test that detects and records the heart's electrical activity.)