The judgment that the heart attack has passed the dangerous stage should be from the significant improvement of symptoms, the normalization of relevant hematological indexes, and the stabilization of electrocardiogram. Acute myocardial infarction is a kind of cardiovascular disease which is more dangerous in clinic, and clinic generally judges whether the patient has passed the dangerous period through the following three aspects: 1. Significant improvement of symptoms: the onset of acute myocardial infarction is usually accompanied by chest pain, sweating, nausea, vomiting, palpitations or dyspnea and other discomforts, and after the patient’s condition enters the stabilization period, the symptoms will often improve significantly or even disappear. 2. Normalization of relevant hematological indexes: After the patient’s condition has passed the dangerous stage, relevant hematological indexes, such as cardiac enzymes and troponin, will return to normal and have no tendency to increase. 3. Stable electrocardiogram: If the electrocardiogram of the patient is stable and there is no ventricular arrhythmia or serious atrioventricular block, it also means that the patient’s condition has stabilized. Patients with myocardial infarction should strictly follow the doctor’s requirements for treatment, and should communicate with the doctor in time if there is any discomfort during the process.