The most common classifications used in clinical center failure patients are killip classification and NYHA classification, each of which has its own applicability, as described below. The killip classification is applicable to acute heart failure caused by AMI. Grade I: No signs of heart failure, but PCWP (pulmonary capillary wedge pressure) may be elevated, with a mortality rate of 0-5%. Grade II: Mild to moderate heart failure with pulmonary rales less than 50% of both lung fields, a third heart sound, sinus tachycardia or other arrhythmias, elevated venous pressure, and x-ray signs of pulmonary stasis, with a mortality rate of 10-20%. Grade III: Severe heart failure, acute pulmonary edema, pulmonary rales greater than 50% of both lungs, 35-40% mortality rate. Grade IV: cardiogenic shock, systolic blood pressure less than 90 mmHg, urine less than 20 ml per hour, cold and clammy skin, cyanosis, accelerated respiration, pulse rate greater than 100 beats/min, and a mortality rate of 85-95%. NYHA classification: applicable to heart failure caused by non-AMI causes. Grade I: Patients with heart disease, but the amount of daily activity is not limited, and general physical activity does not cause excessive fatigue, palpitations, shortness of breath or angina. Grade II: Patients with heart disease have mildly restricted physical activity. No conscious symptoms at rest, general physical activity causing excessive fatigue, palpitations, shortness of breath or angina pectoris. Class III: Patients with heart disease such that physical activity is significantly limited. No symptoms at rest, but less than general physical activity can cause excessive fatigue, palpitations, shortness of breath or angina pectoris. Grade IV: Patients with heart disease cannot engage in any physical activity, and symptoms of heart failure appear even at rest and worsen after physical activity.