What is a MUGA scan?
A multigated acquisition (MUGA) scan is an imaging test to evaluate how your heart pumps blood. It uses an injection of a substance called a radionuclide and a specialized camera. As the radionuclide travels through your blood, your healthcare provider takes pictures of your heart.
A MUGA scan measures how your heart muscle contracts and relaxes while you rest or exercise. Other names for MUGA scans include radionuclide ventriculography (RNVG) and equilibrium radionuclide angiocardiography (ERNA).
What does a MUGA scan show?
A MUGA scan measures your ejection fraction (EF). EF is how much blood your heart pumps out each time it squeezes (contracts).
Doctors measure EF as a percentage. For example, an EF of 70% means that when your heart fills with blood and contracts, it pumps out 70% of the total amount of blood it contains. A typical EF falls between 50% and 75%.
What is a MUGA scan used for?
Your healthcare provider may use a MUGA scan if you have signs of heart failure. In heart failure, your heart doesn’t pump blood as efficiently as it should. Some common symptoms of heart failure include:
- Chest pain (angina).
- Shortness of breath (dyspnea).
- Swollen hands or feet (edema).
Your healthcare provider may order a MUGA scan before or after cancer treatment. Some people have heart damage due to cancer treatments, including:
What is the difference between a MUGA scan and an echo test?
Both a MUGA scan and an echo test create images of your heartbeat. An echocardiogram (echo) is an imaging test to look at how your heart pumps blood. Echocardiograms use sound waves and a device called a transducer that the doctor moves over your chest.
A MUGA scan is a nuclear imaging test that uses a radiotracer. MUGA scans may give your doctor a more precise ejection fraction reading.
How does a MUGA scan work?
MUGA heart scans use small amounts of a radioactive chemical called technetium-99m-pertechnetate (Tc-99m).
Your provider injects a small amount of Tc-99m into one of your veins. The chemical attaches to your red blood cells, the cells that carry oxygen. Your provider takes pictures with a special camera that shows how and where the Tc-99m moves throughout your body as your heart beats.
How do I prepare for a MUGA scan?
Your provider gives you personalized instructions to prepare for a MUGA scan. In general, you’ll avoid eating and drinking for up to six hours before the test. Your provider may also instruct you to avoid caffeine for a period. Caffeine can speed up your heart rate, which may interfere with test results.
Tell your provider about all the medications you take. You may need to stop taking certain heart medicines, such as nitrates (Nitrostat®, NitroMist®) or digoxin (Digitek®, Lanoxin®), before a MUGA scan.
What can I expect during a MUGA scan?
MUGA scans can take one to three hours. During a MUGA scan, you lie still on an exam table with a special camera positioned above your chest. Then, a technician:
- Attaches electrodes that measure heart activity to your chest.
- Injects your vein with the radiotracer.
- Takes pictures from several different views.
Between pictures, the technician asks you to exercise, such as walking on a treadmill. Exercising helps your cardiologist (heart doctor) see how your heart responds to stress.
What can I expect after a MUGA scan?
You can resume your usual activities, such as driving, immediately after a MUGA scan. The day or two after the test, drink plenty of liquids to help flush the radiotracer out of your system.
What are the risks of a MUGA scan?
MUGA scans are safe for most people. The radiotracer isn’t harmful, and it usually leaves your body within 24 hours.
Tell your healthcare provider if you are pregnant, think you could be pregnant or are breastfeeding. Healthcare providers typically don’t recommend these tests for women who are pregnant or nursing, as they could harm their baby.
Results and Follow-Up
What should I know about the results of a MUGA scan?
MUGA scans measure your EF. An EF below 50% or above 75% may point to a heart problem. After the scan, your provider discusses the results and next steps with you, including possible heart treatment.
What else should I ask my doctor?
You may also want to ask your healthcare provider:
- Why do I need a MUGA scan?
- How long does a MUGA scan take?
- Do I need to do anything special to prepare?
- What are the benefits of a MUGA scan?
- What do the test results mean?
- What are my next steps after a MUGA scan?
A note from Cleveland Clinic
A MUGA scan is an imaging test to evaluate how your heart pumps blood. Your healthcare provider may recommend a MUGA heart scan to check for heart conditions such as heart failure. You may also have a MUGA scan to check for signs of heart damage during cancer treatment. MUGA scans are quick, outpatient tests. You can typically resume your usual activities the same day.
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