Cardiac ejection fraction reflects the pumping function of the heart. A cardiac ejection fraction of 20% is considered to be a sign of severe heart failure. Combined with the patient’s own symptoms, further diagnosis and treatment are needed. Each time the heart ejects blood, the contraction of the ventricle does not eject all the blood in the ventricle into the artery, that is, when the ejection of blood is completed, there is still a certain amount of blood left in the ventricle, and the percentage of each ejection of blood to the maximum volume of the ventricle is called the ejection fraction, and it is normally 50% ~ 60%. It is usually measured by echocardiography and is important for the early detection of cardiac function abnormalities in patients with chronic heart failure. It is generally accepted that an ejection fraction of less than 50% indicates the presence of cardiac pumping insufficiency; if it is less than 33%, it indicates severe heart failure. Cardiac ejection fraction of 20 suggests that the patient bed rest, avoid physical labor, timely hospital consultation cardiology, further improve the cardiac enzymology level, assess the heart condition, under the guidance of the doctor treatment.