The causes of slow heartbeat include physiological and pathological causes such as atrioventricular block, etc. A slow heartbeat can lead to insufficient perfusion of organs throughout the body, affecting normal function and even endangering life. The normal heartbeat is 60-100 beats per minute, and a heartbeat slower than 60 beats per minute is considered bradycardia. Bradycardia can occur in athletes, the elderly, and healthy people during physiologic conditions such as sleep. Pathologic causes of bradycardia include cardiovascular diseases such as atrioventricular block, myocarditis, and pericarditis, the use of antiarrhythmic drugs such as metoprolol, and other diseases such as hypothyroidism and hyperkalemia. Bradycardia will lead to a decrease in the pumping capacity of the heart, affecting the blood perfusion of other organs, which will lead to insufficient blood supply to the brain and other conditions, and in severe cases, there will be fainting, coma or even cardiac arrest and other adverse consequences.