Atrial fibrillation: the nonpharmacologic strategy

Abstract

Pharmacologic treatment has been used for decades for conversion and prevention of recurrent atrial fibrillation (AF). But the use of antiarrhythmic drugs is associated with substantial side effects and mortality in some patients. Accordingly, it is not surprising that nonpharmacologic techniques have been developed for the management of AF, including the use of atrial defibrillators, atrial pacing methods, and several surgical and radiofrequency catheter ablation procedures. The atrial defibrillator has been found to detect and treat atrial and ventricular arrhythmias appropriately, with successful termination of spontaneous AF through low energy shocks. Although these devices are promising, the factor which limits their widespread use is not safety or efficacy, but patient comfort. Several studies suggest that atrial-based cardiac pacing may have a beneficial effect in decreasing and preventing AF episodes in patients with sick sinus syndrome. Palliative ablative procedures also available for the treatment of atrial fibrillation include AV junctional modification and AV nodal ablation with permanent pacing, the latter technique being associated with improvements in ejection fraction. Two potentially curative procedures are the surgical MAZE and endocardial catheter ablation. These techniques are based on placing strategically located lesions in the atrium to disrupt the conduction pathway(s). Recent studies have focused on ablative therapies aimed at the area of the pulmonic veins. The main therapy for maintaining sinus rhythm after conversion is predominantly pharmacologic. Similarly, in the absence of heart block, if conversion to sinus rhythm is not successful, pharmacologic modalities may be required to control ventricular rate. In any case, planning a treatment regimen for the management of AF should include evaluation of the risks inherent in the use of various drugs as well as more invasive strategies.