Nuclear Cardiology

Practice Areas

MTWA measures beat-to-beat variations in the amplitude (height) of the T-wave portion of the heartbeat. These variations can identify patients who are at risk of developing ventricular arrhythmia that could lead to sudden cardiac arrest. During this test, you will walk on a treadmill for a short time while an electrocardiogram (EKG) records your heart rate and rhythm. Patients found to be at high risk often receive an implantable defibrillator to stop any arrhythmias that could develop. This test is typically used for patients who have had myocardial infarctions (heart attacks) or other heart damage.

Multigated Acquistion Scan (MUGA)

Also called radionuclide angiography or wall motion study, this test helps the doctor evaluate the pumping function (ejection fraction) of your heart ventricles: the lower chambers on either side of the heart that pump blood into the arteries. MUGA uses three-dimensional ultrasound to provide a movie-like image of the beating heart. It also calculates the amount of blood pumped during each heartbeat so that the strength of the heart muscle can be assessed.

During the test, a small sample of your blood is drawn, tagged with a radioactive substance, then reinjected into the bloodstream. A special camera, which detect the radioactive red blood cells as they move through your heart, will take pictures of your heart from three different angles. more accurate than echocardiography and cardiac catheterization in measuring the pumping capacity of the LV.

Nuclear Stress Test

Usually performed in combination with an exercise stress test, this procedure shows how your heart performs during exercise or other activities that make it work harder. Also known as a thallium stress test, a myocardial perfusion scan, or a radionuclide test, it can help determine if the coronary arteries that supply the heart muscle are receiving sufficient blood flow.

A nuclear stress test uses a small amount thallium, a radioactive substance, to depict blood flow to the heart while you are exercising and while you are at rest. A special nuclear imaging device takes pictures of the thallium as it moves through your heart. If any part isn’t receiving a normal blood supply, less thallium will be visible in those cells.

Pharmacologic (Chemical) Stress Test

For patients who cannot exercise on a treadmill, a doctor can give medications through an IV to simulate exercise. These medications may increase the heart rate or dilate the heart arteries to make it easier for blood to flow in normal arteries. Abnormal arteries will not receive as much blood flow, however. As in a standard nuclear stress test, this will be detected with the nuclear camera.