Secret of ganti(bells)

I understood the secret of ganti whenever Myhra sees Rudra she heard bells and she always says "ganti fir se sunai de rahi" I think that those bells are her heartbeats that she heards whenever she sees Rudra and I conclude from this is that might be Paro's heart was transplant to Myhra to save her. Thats why she feels happy when she is with Dhruv.

I m very much confused now