Test OverviewA cardiac blood pool scan shows how well your heart is pumping blood to the rest of your body. During this test, a small amount of a radioactive substance called a tracer is injected into a vein. A gamma camera detects the radioactive material as it flows through the heart and lungs. The percentage of blood pumped out of the heart with each heartbeat is called the ejection fraction. It provides an estimate of how well the heart is working. There are two types of cardiac blood pool scans. - First-pass scan. This scan makes pictures of the blood as it goes through the heart and lungs the first time. A first-pass scan can be used in children to look for heart problems that have been present since birth (congenital heart disease).
- Gated scan or multigated acquisition (MUGA) scan. This scan uses the electrical signals of the heart to trigger the camera to take a series of pictures that can be viewed later like a motion picture. The pictures record the heart's motion and determine if it is pumping (contracting) properly. MUGA scanning may take 2 to 3 hours to obtain all the needed views and can be done both before and after you exercise. You may be given nitroglycerin to see how your heart responds to this medicine. MUGA scanning may be done after a first-pass scan. It is usually not done on children.
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