ECG refers to 24-hour ambulatory electrocardiogram (ECG), which can usually rule out arrhythmia and other diseases, and provides an important objective basis for clinical diagnosis, treatment of cardiac diseases, and judgment of cardiovascular system disorders. 24-hour ambulatory electrocardiogram is very important for the qualitative diagnosis of arrhythmia and myocardial ischemia. In addition, it can also clearly diagnose the causes of paroxysmal dizziness, syncope, and rapid heartbeat with panic. In addition, the prognosis of cardiac patients can be evaluated comprehensively, and the ability of cardiac patients to perform their daily lives can also be assessed. There is no means of screening for all diseases of the heart. In addition to an ECG, other cardiac tests such as cardiac enzymes and ultrasound can be performed to provide a comprehensive screening of the heart. If there is any abnormality in the 24-hour ECG, it is important to consult a doctor in time to complete the examination and identify the cause of the disease, and standardize the treatment under the doctor’s guidance.