Ejection fraction normally refers to measurements related to the left ventricle of the heart, and patients with an ejection fraction between 55 and 70 percent are in the normal range, notes Cleveland Clinic. Ejection fraction measures how much blood is pumped from the patient's left ventricle during heart contractions.
Left ventricular ejection fractions, or LVEF, may be lower than normal when patients have heart damage due to conditions such as heart attacks or heart muscle disease, states Cleveland Clinic. An ejection fraction of less than 40 percent may indicate that a patient is suffering from heart failure. People with an ejection fraction of less than 35 percent are at higher risk of irregular heartbeats that can lead to cardiac arrest.