How is an ejection fraction performed?

Echocardiography: EF is generally measured using echocardiography. Various types of echocardiography exist, including transesophageal echocardiography (TOE), transthoracic echocardiography (TTE or TEE), and 3-dimensional echocardiography.

Echocardiography is a non-invasive ultrasound test. Transthoracic ECHO is a common test during which the ultrasound instrument is held over the patient's chest. In transesophageal ECHO, the instrument is placed in the patient's esophagus. 3-Dimensional ECHO allows for a 3-D picture of the heart and its chambers. In each case, a sound wave bounces off the heart creating images of the valves and chambers. This test can allow for the determination of the thickness of the heart muscle and can determine how much of the blood is being pumped out of the body.

Multigated acquisition (MUGA) scan or ventriculography: Radioactive substances are injected into the bloodstream using a needle. These radionuclides are short-lived so they do not stay in the body for a long time. The radionuclides go to the heart where they can be seen using computer-generated pictures. This allows for the determination of how well the chambers are working by using mathematical models to determine the left ventricular function.

Computed tomography (CT): A cross-sectional 3-dimensional image of the heart is made during the CT scan. Thus, the volume of blood can be measured in order to determine the EF.

Other: Less commonly used techniques for determination of the EF include cardiac MRI and cardiac catheterization (a catheter or thin flexible tube is inserted into the vein to go to the heart).