After surgery, because surgery requires a knife, and the knife will cause nerve stimulation resulting in pain, so the reason for increased heart rate after surgery should be considered whether there is pain, just like usual, as long as the pain or tension will cause increased heart rate. The second reason should be considered after ruling out the increase in heart rate caused by pain after surgery or the use of adequate analgesics and anesthetics. If there is not enough water in the pump, the heart will beat more times to ensure the blood supply, you can consider increasing the fluid in the vein, so that the blood in the blood vessels are slightly filled up, which can also slow down the heart rate.