Suddenly in the middle of the night, a rapid heartbeat should be considered rapid arrhythmia, left heart failure, etc., as follows: 1, rapid arrhythmia: sudden rapid arrhythmia, such as rapid atrial fibrillation, atrial flutter, paroxysmal supraventricular tachycardia, etc. 2, left heart failure: suffering from left heart failure, left heart failure at night, sudden aggravation of left heart failure. 3, other causes: suffering from hyperthyroidism, severe anemia, as well as sudden low blood pressure, Severe anemia and sudden onset of hypoglycemia and other diseases. For the sudden appearance of rapid heartbeat in the middle of the night, you need to go to the hospital in time, to clarify the causes of rapid heartbeat, and actively target the relevant diseases for treatment, to avoid persistent rapid heartbeat, which will cause adverse effects on the body.