This is the time of year when GPs start offering flu jabs (mine is tomorrow) so for the benefit of newbies, YES it is a good idea since flu can put an unwanted burden on your suffering heart and NO I know of no cases where it has exacerbated AF or affected INR. Since it is a dead virus it can't give you flu of course. Usual proviso check for possible allergies to the base product. I think it is grown in chickens eggs or similar from memory but they should ask you about that before stabbing you.
Only 9 days now to HRC Patients day.