I have not read about any rejection of a pacemaker on this Community, so I think it very unlikely you'll have any problem.
I don't see any relationship, nor do I understand, rejection of a piercing. Was it infection? That's not rejection, that's dirty or something else tools/treatment.
As for you heart, the pacemaker sends it electrical signals, just like the biological signal generator. So rejection at that level seems even more unlikely.
I say the above from what I've read here and from what I know from friends and family who have pacemakers, I do not have one myself (yet).
I'm with Jerry - odds are that the belly button piercing problems are a result of an infection, not your body rejecting it. My buddy and I got each an ear pierced when we first got into college (a looooong time ago). I was constantly cleaning mine, and my buddy not so much. His was always infected, ended up closing. I haven't worn an earring in 20 years, but my hole is still there. So I know that really keeping after it, keeping it clean is probably the reason you had a problem.
I'm sorry that you are in a spot where you have to get a pacemaker so young - from what I hear the procedure is safe and can give you back your life. I hope you find that the same is true. Good luck!
Have you mentioned to your doctor that you have a sensitivity to metals? Many people with piercings find they can only use certain types of rings, whether it's solid gold or surgical stainless. The cheaper rings and posts often cause nasty reactions in folks with metal allergies or sensitivities.
A pacemaker is made with high quality surgical stainless I believe so you probably won't have any reaction to it. Even stainless comes in different types, from the cheap silverware to the special surgical instruments used in hospitals.
I doubt you'll have a problem but just for peace of mind, mention it to your cardio. I'm sure they can test you for reactions. Good luck with the pacemaker.
Ah, good point Irene. I forgot about that.
I just knew about it from my daughter's reaction to earrings and belly button piercing. Even though the piercings were completely healed, certain rings caused terrible eczema and swelling for her. It took awhile to figure out what she could wear and what to avoid. Gold plated was the worst since the plating tends to have pits and the cheap stuff underneath caused a reaction.