Clinical manifestations of acute left heart failure include sudden severe dyspnea, syncope, and shock. First aid measures include general treatment, drug treatment. Clinical manifestations of severe dyspnea due to hypoxia, in order to alleviate the symptoms, the patient needs to take a forced position, extreme hypoxia patients may even even blurred, due to hypoxia caused by pallor, the patient’s cough presents pink foamy sputum. First aid measures should be immediately let the patient to take semi-recumbent position, legs down, reduce venous return, relieve symptoms, immediately give the patient oxygen. After entering the hospital, open the intravenous channel, cardiac monitoring and oxygen saturation monitoring, if necessary, give sedative drugs such as morphine, can be followed up with nitrate, dopamine and other drugs. If the patient has the above symptoms, it is recommended to call 120 or go to the emergency room in a timely manner, active treatment, so as not to delay the condition.