The heart rate is 45 beats per minute.

It depends. If you usually think you are a sports enthusiast, especially if you practice aerobic exercise, 45 should be normal. When I was about 20 years old, I was also in my 50~55 s. That's because aerobic exercise will increase people's vital capacity and heart function, and the blood pumped by a heartbeat can make the body function work normally, so 45 should be normal, provided that you often participate in aerobic exercise. Otherwise, it is recommended to go to the hospital for examination, so as not to miss anything.