Patients with heart rates greater than 120 beats/min and less than 40 beats/min are at risk. Whether the heart rate is too fast or too slow, there is the possibility of an As attack. If heart rate abnormalities are not detected in time to perform CPR, the patient is likely to die suddenly. It is important to monitor the change of heart rate to ensure that the heart rate is within 60-100 beats/min. If there are currently adrenal tumors, congenital heart conduction system abnormalities, pre-excitation syndrome and other diseases, it is important to seek medical attention and take oral metoprolol tartrate, metoprolol succinate extended-release tablets and other drugs to control the ventricular rate to prevent the heart from insufficient blood supply and induce adverse consequences such as angina pectoris, myocardial infarction or sudden death . If the heart rate is too slow, a pacemaker should be placed promptly.