Patients with rapid heartbeat during sleep usually have the following factors: 1. Cardiac neurosis, which occurs at night when the excitability of the vagus nerve is too high, resulting in a rapid heartbeat. 2. Endocrine metabolic diseases, such as hyperthyroidism and hyperadrenocorticism, can also result in a rapid heart rate during sleep. 3. Female patients with endocrine disorders, especially around puberty and menopause, have an imbalance in the secretion of estrogen and progesterone, which can lead to a rapid heartbeat during sleep. 4. Infections, such as bacteria, viruses and atypical pathogens, can lead to increased body temperature, especially during sleep, and can cause tachycardia due to increased body temperature.