Nonpharmacologic therapies for atrial fibrillation.
The limited efficacy and proarrhythmic risks of antiarrhythmic drug therapies for atrial fibrillation have led to the exploration of a wide spectrum of alternative therapeutic approaches. The diversity of the approaches is warranted by the current absence of a single procedure that can safely and effectively cure atrial fibrillation. The interventional therapies that are currently under most active development include implantable atrial defibrillator therapy, prophylactic atrial pacing in combination with drug therapy, multisite regional pace-entrainment of atrial fibrillation by rapid pacing, atrial surgery, and catheter ablation for atrial fibrillation. The current limitations of these procedures include: (1) for the implantable atrial defibrillator--patient tolerance of low energy shocks and early recurrence of atrial fibrillation; (2) for prophylactic pacing-limited efficacy in a small proportion of the total atrial fibrillation population; (3) for multisite regional pace-entrainment--lack of proved efficacy and difficulty in the expansion and merging of the entrained regions; (4) for atrial surgery--highly invasive as a stand-alone procedure; and (5) for catheter ablation-lack of proved long-term efficacy, shortcomings of currently available technology, and risk of thromboembolic stroke. It is evident that more basic and clinical research as well as technologic innovation are needed. However, it is likely that some of these new therapies, possibly in combination with antiarrhythmic drug therapy, will offer considerable clinical benefit to selected patients with symptomatic atrial fibrillation.