Let’s imagine that organs can be perfectly grown in a lab and installed into a body without any chance of rejection or other complications usually associated with organ transplant.
You, a perfectly healthy adult human, go to the doctor and have them put a second heart in your chest that is connected to the circulatory system with your original heart.
What would be the effects of this? Could it even be done in this hypothetical situation at all?
Desychronization will likely happen considering the heart rate is varying. Both must somehow increase by exactly the same rate. Any slight variation will cause them to go out of sync.
Once they’re out of sync, it’s going to be hard for them to get back in sync.
This is assuming both hearts are independent systems. Could be a different story if there dependent (like connected in series rather than parallel), but in that case it’s conceptually no different than having one heart.