The assessment of cardiac function in patients with acute myocardial infarction can be based on the criteria of Killip classification, and the cardiac function classification can be divided into Class I, Class II, Class III and Class IV. 1. Grade I: The criteria of grade I is no heart failure and no clinical manifestations of cardiac insufficiency. 2. Grade II: Grade II is characterized by heart failure, pulmonary rales less than 50% of the lung fields, a third heart sound, and elevated venous pressure. 3. Class III: Class III is characterized by severe heart failure with pulmonary rales greater than 50% of the lung fields. 4. Class IV: Class IV is characterized by cardiogenic shock, hypotension, peripheral vasoconstriction, oliguria, cyanosis, and sweating. Cardiac function classification is usually used to evaluate the cardiac function of patients with heart disease, in addition to the Killip classification standard, there are other classification standards, the specific classification is recommended to consult the attending physician.