Heart, front view
Heart, front view
MUGA test
MUGA test

Nuclear ventriculography (MUGA or RNV)

Definition:
A test that uses radioactive tracers to delineate heart chambers and major blood vessels leading to and from the heart. The procedure is non-invasive. The heart structures are not touched by instruments.

Alternative Names:
RNV; Cardiac blood pooling imaging; Nuclear heart scan; Radionuclide ventriculography; MUGA

How the test is performed:
A radioactive isotope is injected into your vein. Commonly used isotopes include technetium and thallium. Radioactive isotopes attach to red blood cells and pass through the heart in the circulation. The radioactive isotope can be traced through the heart using special cameras or scanners. The images may be synchronized with an electrocardiogram. The test is often given at rest then repeated with exercise or after administering certain medications.
How to prepare for the test:
If exercise testing is to be done, you may not have food and beverages containing caffeine or alcohol for 3 hours before the test. Wear comfortable shoes, socks, and clothing that permits exercise.

Infants and children:
The physical and psychological preparation you can provide for this or any test or procedure depends on your child's age, interests, previous experiences, and level of trust. For specific information regarding how you can prepare your child, see the following topics as they correspond to your child's age:
How the test will feel:
Electrodes may be placed on your chest. An intravenous catheter will be placed in your arm to inject the radioactive isotope. A camera or scanner will be placed over the chest area to process the images. The scan may be repeated during exercise on a treadmill or stationary bicycle.
Why the test is performed:
The test may be performed to detect a heart attack, to evaluate those at risk of coronary artery disease without invasive testing (coronary angiography and heart catheterization), and to evaluate heart wall motion and pumping function of the heart.
Normal Values:
Normal results indicate normal heart valve and chamber structure and function, or a normal cardiac response to exercise.
What abnormal results mean:
Abnormal results may indicate a myocardial infarction, coronary artery disease, heart valve disease, or other cardiac disorders.

Additional conditions under which the test may be performed:
What the risks are:
People undergoing nuclear scans are exposed to ionizing radiation and the amount of exposure varies with the test. However, the effects are cumulative, and the potential for health hazard caused by radiation is greater in the very young and very old. The potential benefit of the test must be weighed against the risk. These tests are not performed in pregnant women. There is minimal risk associated with the intravenous catheter.

Review Date: 8/28/2001
Reviewed By: Elena Sgarbossa, MD, Section of Cardiology, Rush-Presbyterian St. Luke's Medical Center, Chicago, IL. Review provided by VeriMed Healthcare Network.
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