In clinical practice, a heart rate of 51 beats per minute is considered an abnormal heart rate. The heart rate of a normal person is generally 60-100 beats per minute, while the heart rate of most people fluctuates, basically remaining between 60-80 beats per minute. When the heart rate exceeds 100 beats per minute, it is called tachycardia; when the heart rate is less than 60 beats per minute, it is called bradycardia. Therefore, when the heart rate is 51 beats per minute, it is still necessary to clarify the cause, such as pathological sinus node syndrome, and a 24-hour ambulatory electrocardiogram is needed to clarify the diagnosis. Also, if the patient has frequent symptoms such as dizziness and blackouts, it may also be necessary to implant a pacemaker to improve the symptoms.