Son 24 for 2 yr on this med now has 17% decrease in lung diffusion + some atrial fib incidents: had 4 successful cardioversions all the while on Amiodarone. This time doc stopped Amio. & started Digoxin, Diltiazem, Coreg, and has returned to sinus rhythm but doc decided to put back on Amiodarone! Is this the only option?