Heres some relief for anyone wondering...:
The rhythm of a transplant heart will NEVER be the same in a new host.
When the nerves get severed for transplant, it stunts (or fully disconnects) its connection to any vagal autonomic nervous system & well, the rest of the body. It can gradually recover over several years and start to reeintegrate its nerval connection, but no matter what, that rhythm will never be the same.
Plus, the electric current that goes through your heart, even without a defect or disease, will be unique enough to be noticeable. It has plenty of harmless variantion... whilst some can be progressivy declining, which can be deadly; a Left BBR.
Never skip an EKG folks, lol.

that give me the ick, listening to his heart? is he thinking about his past lover??