Once the body appears chest tightness, angina, arrhythmia and other symptoms, it is a harbinger of heart attack. 1. Chest tightness: when the work pressure is increasing and the spirit is in a highly tense state for a longer period of time, the phenomenon of chest tightness, shortness of breath and inability to breathe will occur, which may indicate the precursor of heart attack. 2. Angina pectoris: patients will appear in a short period of time chest pain, usually lasts for about ten seconds, mainly in the left chest pain, there is a sense of boredom, some patients with angina pectoris lasts longer, the incidence is high, usually in three or four minutes, signaling the advent of heart attack. 3. Arrhythmia: some patients have palpitations, fatigue, cough and other symptoms, serious pulmonary edema, which is related to heart attack. In addition, the electrocardiogram shows that the ST segment is transiently and obviously elevated or depressed, and the T wave is inverted or increased, which should be alert to the possibility of MI in the near future. The detection of aura and timely and active treatment may make some patients avoid the occurrence of MI, and it is recommended that patients should be treated according to the examination results and with the help of doctors.