Rapid heartbeat during naps can be episodic, intermittent or continuous. The main causes of tachycardia are faster heartbeat, compensatory increase in myocardial ischemia and cardiac insufficiency. In addition to normal conditions, the following diseases can also trigger: 1. paroxysmal tachycardia, reduced activity during naps, more relaxed emotions, sudden changes in state can lead to transient arrhythmias, which can occur episodically. 2. angina pectoris, myocardial infarction, changes in body position or even when there is no trigger, can trigger the occurrence of angina pectoris and myocardial infarction, resulting in myocardial ischemia, prone to compensatory rapid heartbeat. 3. in cardiac insufficiency The rapid heartbeat is caused by systolic and diastolic dysfunction of the heart and insufficient blood supply to the heart.