Symptoms of cardiac infarction are clinically manifested in a variety of ways, mainly the following: 1, some non-specific symptoms. There are some patients before the onset of the disease can be manifested as generalized fatigue, activity panic, shortness of breath, irritability, chest discomfort and other non-specific performance. 2, the first discovery of angina pectoris. This part of the patient was healthy, suddenly frequent attacks of angina pectoris, then we should pay attention to the possibility of myocardial infarction.3, the original angina symptoms aggravated. For example, patients used to have angina, but has been relatively stable, as long as not more than a certain amount of activity, generally do not have an attack, but the recent aggravation of a smaller amount of activity can be attacked, the number of attacks per day is also more, the use of nitroglycerin and other drugs is not good, and even in the rest of the state can be attacked, which may be a precursor to myocardial infarction, we must be particularly vigilant.