Intercardiac interval is generally defined as the time between two heartbeats and may be caused by preterm contractions, sinus node disease and atrioventricular block. Often preterm contractions may occur in normal people, which means that the patient’s heart beats early, followed by a long interval, and then the heart beats again in between. The patient usually feels palpitations and panic, e.g. overwork of the patient, drinking strong tea and coffee may cause preterm contractions. In addition, some patients have diseases that cause intermittent heartbeats, such as sinus node disease and atrioventricular block. Some of the electrical activity of the heart fails to occur, or the conduction process is blocked, causing the patient to experience a temporary cardiac interval. It is recommended that patients who experience cardiac intervals should actively seek medical attention and undergo relevant examinations and treatments under the guidance of a medical professional.