Arrests greater than 2.50 seconds are not normal. The frequency of sinus rhythm in a normal adult is 60 to 100 beats per minute, and the interval between two heartbeats is about 0.6 to 1 second. Sinus arrest can be seen in coronary heart disease, cerebrovascular accident, sick sinus node syndrome, severe atrioventricular block, and the application of certain drugs such as digitalis, etc. When the duration of sinus arrest is greater than 3 seconds and there is no escaped beats occurring, the patient will suddenly have a blackout, fainting, and other symptoms, and sometimes even death will occur. Cardiac arrest greater than 2.50 seconds, also seen in some of the diseases that cause bradycardia, such as hypothyroidism, vasovagal syncope. Feeling abnormal heartbeat, you must go to the hospital in time, to clarify the cause of the disease, under the guidance of the doctor, do not delay, so as not to delay the condition, resulting in irreparable consequences.