hi I have read through your question and understand your concern. In congestive cardiac failure , the patient usually becomes very breathless even on talking a sentence and even on doing daily activities. according to what you have mentioned, your grandfather seems to be quite alright and independant which is a good sign. -AF is ofcourse a risk, but this may most likely not revert so easily considering his age, and heart disease which may have resulted in structural changes that make reverting the heart disease difficult. -Using unnecessary and excessive medication may only worsen the condition,quality of life and have severe side effects, that generally tend to worsen the heart condition. -So the meds are given on calculating a risk /benefit ratio. -As he is quite well now you may have no reason to worry. you can ask him to go for a walk daily, and check if he s able to go the same distance everyday comfortably. If you see that he is not able to cover the distance or feels breathless to cover the same distance you can take him to your doctor to check his status. (this is somewhat a modified threadmill test) -Ask your doctor if he could consider some anticoagulant medicines. as thromboembolism is 5 times more common in AF patients than normal people. Wish him a speedy recovery...!! god bless..