Relativity. There are no perfect treatments for af. The most effective, amiodarone, unfortunately has the most serious long term toxicity. The problem with all other meds (except simple beta blockers and calcium blockers) is that they can cause other, more life threatening arrhythmias. The most important risk factor is the presence of cad. Other than that, trial and error is the best bet (with exceptions).
It depends. I need more specifics about your left ventricular function, and whether the a.Fib is paroxysmal or not.