Middle English (Scots) carne, from Scottish Gaelic carn; akin to Old Irish & Welsh carn cairn
Ejection fraction is commonly measured by an echocardiogram and serves as a general measure of a person's cardiac function. Ejection fraction is typically low in patients with the systolic form of congestive heart failure.
A normal left ventricular ejection fraction (LVEF) is 50 to 75 percent. Other tests used to measure EF include cardiac catheterization, magnetic resonance imaging (MRI), computed tomography (CT), and nuclear medicine scans. A low EF number is an early sign of heart failure.