Probably something totally new. I think the transplant process can mess with the heart beat and how it responds to things like exercise. The recipients lifestyle I’m sure would change how the heart beats. Also the anatomy of the heart changes how it beats so like if the donor had a condition like Long QT then i would think the recipient will have Long QT since that condition is caused by abnormality in the ion channels of the heart which is usually the result of a genetic change in the donor.