A MUGA (a Multiple Gated Acquisition) scan is a test that uses a radioactive substance, called a tracer, to access how well your heart is pumping blood.
During MUGA scan, a small amount of radioactive tracer is injected into a vein in your arm. The tracer “tags” or “labels” your red blood cells by attaching to them for a few hours.
The tagged red blood cells distribute evenly in your blood. As these cells travel through the heart, the tracer gives off a slam amount of radiation that can be detected with a scanning camera. A computer processes the information and produces images that show how radioactivity is distributed in the heart.
The camera is linked to an electrocardiogram (ECG). Your heart’s electrical signals trigger the camera to take a series of pictures at precise moments during the heartbeat cycle. This is called “gating”.
Gating creates images that are sharp and clear. Is also produces moving images that show the left and right lower chambers, or ventricles, as they contract and pump blood.
When Can a MUGA Scan be Ordered?
After a heart attack, to assess how much damage was done to the heart muscle
To access the size and pumping strength of the ventricles in patients with heart failure and/or heart muscle disease (cardiomyopathy),
During chemotherapy for cancer, to monitor the ventricles’ pumping strength , because some cancer drugs can be harmful to the heart.
An exercise MUGA scan may be done to detect poor blood flow to the heart muscle, which may indicate a coronary heart disease.
Preparing for a MUGA Scan
For a rest MUGA scan: no special preparation is necessary
For an exercise MUGA scan:
- Do not eat, drink, or smoke for at least 3 hours before the test.
- If you take heart medications, check with your doctor. You may be asked to stop certain medications a day or two before the test.
- Wear comfortable clothing and shoes that are suitable for exercise. No slippers or flip-flops are allowed.
What to Expect?
A rest MUGA scan usually takes less then an hour.
If the test also includes an exercise scan, it may take up to 3 hours.
After the test, you can resume your normal activities, including driving.
Is the Test Safe?
The radiation exposure during a scan is small, and the doses used are safe. However, if you are pregnant, suspect you may be, or are a nursing mother, let your doctor know.
The exercise test is also safe. Possiblecomplications are rare and include abnormal heart rhythms and a heart attack. Trained personnel are there to handle any emergency.