Is it possible to reach into somebody and rip their heart out

Would the heart still beat after you ripped it out?

Nope. Think about where you have to reach in.
1. You punch in through the ribs. Good luck getting an intact heart out like that.
2. You punch under the ribs, through the diaphragm and lungs. Do you think you can punch through the diaphragm without pulverizing the heart? Doubt it.

Those old kung fu movies sure look cool. But don't expect realism. Ditto the videogames.