If the patient has high blood pressure, diabetes, high blood lipids, smoking, alcohol abuse, obesity, family history of coronary heart disease, and develops persistent chest pain or with back pain, radiating pain, profuse sweating, nausea, vomiting, or even a sense of near-death, acute infarction should be highly suspected. What to do before the arrival of ambulance medical personnel? First, call the 120 emergency number, keep the phone open, and send someone to meet the ambulance to shorten the time for the emergency personnel to find the patient. Second, monitor the patient’s condition, you can observe consciousness, respiration, blood pressure, pulse and so on. Oxygen can be administered if possible. Third, let the patient rest quietly and avoid all stimulation. If the onset is due to emotional excitement, try to stabilize the mood. If the onset of the disease is due to exercise, stop exercising immediately. Let the patient lie down, but if the patient has difficulty breathing, wheezing, to sit, legs down. If there is dizziness, low blood pressure, must lie flat. If there is again dyspnea and low blood pressure, only semi-recumbent position. Fifth, you can apply emergency drugs, including chewing aspirin 300mg, each tablet is 100mg of a total of 3 tablets. Can also be sublingual nitroglycerin tablets 1 tablets. Aspirin and nitroglycerin both drugs are contraindications, the general public is usually difficult to grasp, you can call the phone by 120 emergency doctors to decide to use or not. Sixth, always be prepared for CPR.