I am due to have a cardioversion for afib, how long after the procedure is it safe to fly. i have an 11 hour flight booked. ?

Cardioversion: Whether the elective cardioversion is effective or not, as long as there has been no new heart injury and as long as you remain on anticoagulants and whatever antiarrythmic medications prescribed, there should be no problem with flying or travelling after a couple of days in my opinion. However your cardiologist is best qualified to advise you about this matter. Get up and walk around the plane.

Atrial fibrillation : That answer will be totally up to the cardiologist who did the cardioversion. You might not get the same answer from any two cardiologists It will depend on how likely they are to think that it is safe. You will need to ask them. Good luck.