I almost forgot to clarify.. damage to bundle branches is called an "av nodal conduction block' or "avblock".. "avb" or "avn block"..
So it sounds like thats whats goin on
Mechanical aortic valve replacements carry a high risk of damaging the bundle branches.. these bundle branches are basically the wiring that provides electricity to the heart.
Sometimes the damage heals, other times its permanent... sometimes the damage isnt severe
Other times the damage to the wores is significant enough to warrant placement of artificial wires... aka a pacemaker.
Prognosis is good in any case.. pacemaker implants these days are relatively low rosk procedures.. and theyre so small you barely notice them once you heal. So she should be fine.
The most important thing is that her valve looks good.