I was diagnosed 2 years ago. I am in constant afib.. I hold a special issuance 1st class from the FAA. I take no meds other than 1 aspirin a day. I am asymptomatic. The need for anticoagulants is determined by your "CHADS" score.
C Do you have congestive heart failure
H Do you have hypertension ( high blood press)
A Are you over 75 years of age
D Are you diabetic
S Do you have a history of stroke or TIA
For the FAA, you must have a thallium stress test, echo cardiogram, and wear a Holter monitor for a 24 hour period.
After that, the flight surgeon will make a determination of your fitness for the appropriate class of medical.
Best of luck