What is a Cardiolite Scan?
A Cardiolite scan is a test that uses a radioactive substance, known as a tracer, to produce images of heart muscle. When combined with an exercise test, the
Cardiolite scan helps determine if areas of the heart are not receiving enough blood. The exercise Cardiolite scan is especially useful in diagnosing coronary heart disease, the presence of blockages in the coronary arteries (the vessels that supply oxygen-rich blood to the heart muscle). (Other terms used to describe the Cardiolite scan include: sestamibi scan, myocardial perfusion scan, and cardiac nuclear
imaging.) Other tracers, such as thallium, may be used for this type of scan. In some cases, doctors use two tracers during one test (dual-isotope imaging). What Does it Show?
During the test, a small amount of Cardiolite tracer is injected into a vein in your arm while you walk on a treadmill or pedal a stationary bicycle. The tracer travels in the bloodstream, is carried through the coronary
arteries, and is picked up by the heart muscle cells. Areas of the heart muscle that have an adequate blood supply pick up the tracer right away and more completely. Areas that do not have an adequate blood supply pick up the tracer very slowly or not at all. The tracer gives off a small amount of radiation that is detected with a scanning camera. A computer processes the information and produces images of
the radioactivity distributed in the heart. If an area of the heart receives less blood than the rest of the heart (because of a blocked or narrowed artery), it will pick up less radioactivity and will show up as a
lighter area, called a "defect." Additional Cardiolite is injected while you are at rest, and another set of images is taken. This allows doctors to compare how much blood flows through the heart muscle during stress and at rest. Either the exercise or rest portion of the test may be done
first. The entire test can be completed in either one day or two separate days. Preparing for the Test
Do not eat or drink for 4 hours prior to the test. This will help prevent the possibility of nausea, which may accompany vigorous exercise after eating. Sips of water are okay. If you are currently taking any heart medications, check with your doctor. He or she may ask you to stop certain medications a day or two before the test. This can help get more accurate test results. Wear loose and comfortable clothing that is suitable for exercise. Men usually don't wear a shirt during the test; women generally wear a lightweight blouse or hospital gown. Also wear comfortable walking shoes or sneakers. Before the test, you'll be given a brief explanation of the test and you'll be asked to sign a consent form. Feel free to ask any questions about the procedure. CONTINUE>
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