Bradycardia is a common arrhythmia disease. The normal adult heart rate is between 60 and 100 beats per minute, and if it is below 60 beats it is called bradycardia. Some people usually have a slower heart rate, such as athletes, and many will have a heart rate of 50-60 beats per minute, and some will have a heart rate of less than 50 beats per minute. For patients with bradycardia, if the heart rate slows down, dizziness, transient darkness, weakness, palpitations, chest tightness, shortness of breath, and sometimes a feeling of shock in the precordial region, and in severe cases, syncope may occur. Other patients may present with symptoms of dizziness, weakness, and syncope, and the examination may reveal intermittent prolonged cardiac arrest. In acute episodes of bradycardia, in addition to treating the primary cause and discontinuing drugs that slow the heart rate, atropine and isoprenaline can be used to increase the heart rate. For patients with a heart rate of 40 beats per minute or slower, the effect of drugs to increase the heart rate is not obvious, especially in patients with recurrent syncope or precursors of syncope, a pacemaker should be placed. The pacemaker is about the size of a matchbox and weighs between 25 and 50 grams. The pulse generator is buried under the skin in the upper chest, and the pacing leads are sent to the heart through the veins to stimulate the heart with a certain pulse current, which helps the heart to contract and improve the heart rate. Patients with bradycardia must be treated promptly to avoid life-threatening problems.