When, how, and why should sinus rhythm be restored in patients with persistent atrial fibrillation?

The results of the AFFIRM (Atrial Fibrillation Follow-up Investigation of Rhythm Management) trial indicate that the rate control strategy is preferred for the majority of patients with paroxysmal and persistent atrial fibrillation (AF). If the patient remains symptomatic despite adequate rate control or if rate control cannot be achieved, then rhythm control therapies are indicated. The most likely explanation for the disappointing results of the AFFIRM trial is the poor efficacy and excessive toxicity of rhythm control medications, because the presence of sinus rhythm was associated with a favorable prognosis in AFFIRM. As a result, there is currently great interest in nonpharmacologic therapies such as AF ablation and development of new drugs for AF with a more favorable efficacy and toxicity profile. AF ablation should be reserved for patients who fail an initial trial of a rhythm control medication until additional clinical trial information is available to justify the use of AF ablation as first-line therapy. When rhythm control therapy is indicated, the choice of antiarrhythmic medication should be dictated by the presence or absence of structural heart disease, congestive heart failure, renal dysfunction, or other comorbidities in order to maximize efficacy and minimize the chance of proarrhythmia or extracardiac toxicity.