Gated Blood Pool Scan

A gated blood pool scan is a test that uses radioisotope dye to show how blood pools in the heart during rest, exercise, or both. The test determines how well the heart is pumping blood, and if it is working harder due to one or more blocked arteries. This test is very useful for determining a patient’s “ejection fraction,” which is the percentage of blood that is pumped out of the ventricles with each heartbeat. Another name for this test is a multi-unit gated analysis (MUGA).

How It Works

Radioactive dye is injected into the patient’s bloodstream. The dye is safe and does not harm the blood or organs, but it does “tag” or “label” red blood cells. Doctors then use a gamma-ray camera to take pictures of the heart as the tagged red blood cells circulate.

What to Expect

Patients receive protocols from their doctors regarding eating, drinking, and smoking prior to the test and regarding taking medication before the test, including insulin and inhalers. Patients who undergo an exercise gated blood pool scan should wear exercise clothing and shoes. Lotions or creams should not be used on the day of the test. Patients who may be pregnant or breastfeeding should talk to their doctor before scheduling the test.

A technician applies electrodes, leads, and other monitoring devices, and sets up the nuclear imaging computer. The dye is administered, and the test is performed with the patient lying on an examination table with a special camera around it. The technician takes pictures of the heart with the gamma-ray camera.

If the patient has an exercise gated blood pool test, the patient is placed on an examination table with pedals at the end of the bed. The patient pedals while lying down, as if riding a bicycle. Using the gamma-ray camera, the technician takes pictures of the heart. Normal activities may be resumed after the test. Patients may feel tired. The harmless radioactive substance will leave the body within 2 or 3 days.


Texas Heart Institute