Bradycardia, also known as bradycardia, is an important type of arrhythmia. Heart rate of normal adults ranges from 60 to 100 beats per minute. If it is lower than 60 beats, it is called bradycardia. Some patients usually have a slow basal heart rate, about 50 to 60 times per minute, or even less than 50 times, and usually have dizziness, fatigue, mental retardation symptoms. Some patients usually have normal heart rate, bradycardia can suddenly appear, drop to below 40 times per minute, can appear dizziness, transient eye darkness, fatigue, palpitation, chest tightness, shortness of breath, sometimes there is a sense of impact in the precordial area, serious can occur syncope. There are also some patients with dizziness, fatigue, syncope symptoms of treatment, examination can be found in the heart intermittent arrest for a long time. In the treatment of bradycardia, if the patient's symptoms cannot be reversed after correcting the reversible causes and eliminating the influence of drugs, pacemaker implantation is necessary.