From the Guidelines
A MUGA scan is a nuclear medicine test that evaluates heart function by measuring how well your heart pumps blood, particularly useful for assessing left ventricular ejection fraction (LVEF). This test is commonly recommended for patients undergoing chemotherapy treatments that may affect heart function, those with heart failure, or individuals with coronary artery disease 1. The procedure involves injecting a small amount of radioactive tracer into the bloodstream, which attaches to red blood cells, and then tracking these cells as they move through the heart using a special camera 1.
Key Points About MUGA Scans
- MUGA scans are used to assess left ventricular ejection fraction (LVEF), which is the percentage of blood pumped out of the left ventricle with each heartbeat 1.
- The test typically takes about 1-2 hours, requires minimal preparation, and exposes you to a very low radiation dose 1.
- MUGA scans offer more objective and reproducible measurements of ejection fraction compared to echocardiograms, making them valuable for tracking changes in heart function over time 1.
- The results provide doctors with precise measurements of the heart's pumping efficiency, helping guide treatment decisions for heart conditions or monitoring cardiac effects of certain medications 1.
Clinical Recommendations
- MUGA scans are recommended if echocardiogram is not available or technically feasible, with preference given to cardiac MRI 1.
- Patients with clinical signs or symptoms concerning for cardiac dysfunction should undergo a diagnostic workup, which may include a MUGA scan 1.
- Referral to a cardiologist is recommended based on findings from the MUGA scan or other diagnostic tests 1.
From the Research
Definition of Multiple-Gated Acquisition (MUGA) Scan
- A MUGA scan, also known as multigated acquisition radionuclide ventriculography, is a medical imaging technique used to evaluate the function of the heart's ventricles 2, 3, 4, 5, 6.
- It is considered the gold standard for measuring left ventricular ejection fraction (LVEF) because it is accurate, machine-interpreted, and reproducible 2.
Uses of MUGA Scan
- MUGA scans are used to assess the heart's pumping function, particularly in patients with heart failure or those undergoing cancer treatment that may affect the heart 3, 4.
- They can help identify patients at risk of cardiac complications before undergoing major noncardiac surgery, such as abdominal aortic reconstruction 5, 6.
- MUGA scans can also be used to monitor the effectiveness of treatments for heart failure and to detect any changes in the heart's function over time 3.
Comparison with Other Imaging Modalities
- MUGA scans have been compared to other imaging modalities, such as echocardiography, in terms of their ability to measure LVEF and predict cardiac risk 2, 3, 4.
- Studies have shown that MUGA scans and echocardiography may not always correlate well, and that the choice of imaging modality may depend on the specific clinical context and patient population 4.
- Other tests, such as stress-echocardiography and myocardial perfusion imaging, may be used selectively in moderate-risk patients to refine the prediction of cardiac risk 6.