Heart attack, is myocardial necrosis caused by acute and persistent ischemia and hypoxia of the coronary arteries. Chest discomfort, epigastric, shoulder and back pain, accompanied by nausea and vomiting are the symptoms of heart attack. 1. Chest discomfort: Chest pain is one of the first symptoms of heart attack, which mostly occurs after a full meal, emotional excitement, exercise, or straining to defecate; if it persists without relief, or sudden chest tightness or chest pain when resting, it is highly suspected to be the precursor of heart attack. 2. Epigastric, shoulder and back pain, accompanied by nausea and vomiting: a small number of patients in the occurrence of heart attack pain is not typical, manifested as a sudden onset of abdominal pain, shoulder and back pain, or even toothache, can not be relieved, but also induced a series of systemic symptoms, such as: cold sweats, nausea, vomiting, and even the emergence of cardiac arrhythmia, hypotension and so on, if the pain is accompanied by these symptoms, most of them belong to the state of the occurrence of myocardial infarction. In addition, some patients with heart attack have no other discomfort before the attack, but suddenly develop symptoms such as stuffiness, fatigue, cold sweat, accompanied by panic, tightness of breath, etc., which are progressively aggravated. When similar symptoms are found, it may be the precursor of heart attack. Severe heart attacks can easily lead to cardiac arrest. It is recommended to call 120 emergency number at the first time when encountering a heart attack patient, and perform artificial CPR if possible.