If the patient’s current heart rate is 54 beats/minute at rest, this is indeed abnormal. The standard heart rate range for an adult at rest is 60-100 beats/min. If the patient’s heart rate is 54 beats/minute during sleep, this is relatively normal, and even in some people the heart rate reaches 40 beats/minute during deep sleep, which is also a relatively normal phenomenon. In addition there are some people, such as coronary heart disease, angina pectoris, the current is deliberately to control the heart rate at about 55 times / min, this situation is also relatively normal. Because the slower the heart rate in the safe range, the relative myocardial oxygen consumption will be less, the patient will be less likely to attack angina. So there are some people who have a slow heartbeat, which may be caused by taking certain medications on purpose, and this is also relatively normal. Others, for example, have a heart rate of 60-70 beats/minute at rest, and then suddenly have a heart rate of 50 beats/minute, which may be caused by specific medications or hypothyroidism.