Flecainide
"I have been experiencing increasing episodes of atrial fibrillation over the past 8 months, going from one or two "blips" a day to recently probably 70% of the time!  Not debilitating, but annoying.  Doc put me on two 50 mg flecainide per day.  I started yesterday, and so far so good.  Not a single episode and so far no noticeable side effects, but then today is my first real "day" on the medicine.  I resist taking anything for systemic problems like this, but if it can have this dramatic of positive effect with no side effects, I'm all for it."