C509 George's means

Due to the weakening of the breastbone to the kinetic energy of the shrapnel, coupled with the self-shrinking power of the heart muscle, the shrapnel finally did not pierce through the heart. Otherwise, Guan Ruyu would have died on the spot, and would not have been able to endure until now.

At this time, Guan Ruyu's heart had stopped, making it convenient for him to perform the operation