Another alternative to the echocardiogram is the multiple gated acquisition (or MUGA) scan, a form of cardiac blood pool scan. In a MUGA scan a patient is injected with a small amount of radioactive liquid, which is detected by a special camera as the liquid passes through the bloodstream.

This procedure generates a stop-motion image of the beating heart and measures the amount of blood ejected by the left ventricle with each beat—a good indicator of overall heart health.

The images of the walls and valves of the heart produced by MUGA scans are more accurate and detailed than the ultrasound images generated by an echocardiogram, especially in obese patients, and are helpful in diagnosing heart failure or heart valve disease.

The scans are primarily used to monitor heart transplant patients and cancer patients undergoing chemotherapy regimens that are potentially harmful to the heart (namely doxorubicin).

As with any procedure that uses radiation, MUGA scans carry a very slight inherent risk, but occasional scans are considered to be safe.