If the patient has a rapid heartbeat while lying down. Consider the possibility that the patient, there is a certain degree of heart failure. General heart failure patients, after lying down after the increase in the return of blood flow, will induce patients to appear chest tightness, shortness of breath, wheezing situation, at the same time the patient will be accompanied by rapid heartbeat. When sitting up, this situation will be relatively relieved to some extent. Maintaining a seated position with legs down is a very beneficial position for patients with heart failure. In some patients, there is an association with a disorder of plant nervous system regulation or cardiac neurosis. It is recommended that patients undergo an ambulatory electrocardiogram, BNP, cardiac ultrasound, pulmonary CT, and arterial blood gas analysis if necessary. In addition to these causes, in some patients, bilateral pleural effusion may lead to rapid heartbeat after lying down.