ECG examination is suitable for the following groups of people: 1, people with symptoms of precordial discomfort, such as chest tightness, palpitations, shortness of breath, chest pain, black haze in front of the eyes, etc., should have ECG examination in time to exclude myocardial ischemia, premature beats, tachycardia, conduction block and other cardiac lesions; 2, for patients with common cardiovascular diseases, such as coronary heart disease, primary hypertension, myocardial infarction, stroke, etc., such as onset trends, search for early Preventive measures and objective and fair evaluation of the effectiveness of certain cardiovascular drugs and treatments, ECG is undoubtedly one of the common and important indicators in the investigation and research, such people should do ECG examination regularly to make auxiliary reference for clinical medication; 3, in patients with fever, infection, etc., regardless of age, especially those with abnormally high cardiac enzyme examination, ECG examination should be done promptly to exclude myocarditis lesions; 4, in patients with diarrhea 4. Patients with diarrhea, regardless of their age, should also have an electrocardiogram done promptly. Because severe diarrhea can lead to electrolyte disorders, doing ECG can provide an auxiliary check on the patient’s blood potassium situation and provide some help to clinical treatment.