Atrial Fibrillation

To the Editor: In their review of atrial fibrillation management, Michaud and Stevenson (Jan. 28 issue) 1 indicate that rate control in patients with atrial fibrillation is generally initiated with a beta-blocker, with dose adjustment to reduce the heart rate. In evaluating beta-blocker therapy, it seems relevant to consider that most controlled trials have shown an increase in exercise tolerance with the use of digoxin and a nondihydropyridine (non-DHP) calcium-channel blocker in contrast to a decrease in such tolerance with beta-blocker use in three of nine trials, despite a greater reduction in heart rate. 2,3 In a randomized, controlled study comparing digoxin . . .