Flecainide is used to prevent certain types of life-threatening irregular heartbeats. Flecainide is in a class of medications called antiarrhythmics. It works by slowing electrical signals in the heart to stabilize the heart rhythm.
Occasional A-Fib: In this case it's called paroxysmal atrial fibrillation. You may have symptoms that come and go, lasting for a few minutes to hours and then stopping on their own.
Chronic A-Fib: With chronic atrial fibrillation, symptoms may last until they're treated.
It does sound like you have sx of occasional Atrial Fib.
I hope someone with this condition does respond to your posts.