@missalan, different studies were contradictory on the afib issue. Research seems to have stopped by 2015. This Epic study from mychart information published last year is interesting if not reassuring. https://www.epicresearch.org/articles/some-bone-density-treatments-linked-to-increased-likelihood-of-heart-attack-and-atrial-fibrillation/
There is speculation that because Reclast is such a sudden influx of a large amount of medication, there may be more incidents during the initial inflammatory phase following administration. There is also speculation that because those on osteoporosis medications are older an thereby more likely to be troubled by afib anyway that the incidents of afib are not reflective of the medications effect.
It is widely agreed (among those not taking the drugs) that the benefits of not fracturing are worth the risk.
You might insist on a lower dose they say 4mg works just as well as 5mg. You might ask for Zometa which is a 3mg dose. You might ask for a single dose of steroid before the infusion.
There is ibandronate an in clinic push injection with witch the afib effect has not been seen.
I hope you have good doctors who will recognize the dilemma.