A heart rate of 51 beats per minute is considered bradycardia. A normal adult heart rate is 60-100 beats per minute, and if it is less than 60 beats per minute, it is considered bradycardia. If the heart rate is 51 beats per minute, an electrocardiogram should be performed under the guidance of a cardiologist to determine the cause of the phenomenon so that effective medication can be given. In the case of patients without organic heart disease, it is necessary to pay attention to rest, not to stay up late, and to participate in aerobic exercise appropriately to improve the autoregulation of the heart muscle and achieve a normal heart rate. If it is caused by organic heart disease, the heart rate needs to be increased while treating the organic disease to meet the blood supply to the periphery as well as to the vital organs.