No enrollment

The hypothesis of this study is that by facilitating reverse atrial remodeling with maintenance of sinus rhythm in the weeks preceding ablation makes it feasible to perform a simple pulmonary vein isolation (PVI) with results equivalent or superior to more complex atrial ablation for patients with persistent AF.

Atrial fibrillation (AF) is the most common cardiac disorder currently affecting 2.3 million U.S. adults with an expected increase in incidence to 5.6 million by the year 2050. Randomized clinical trials have shown that ablation was superior to antiarrhythmic drug (AAD) in maintaining sinus rhythm among patients with symptomatic predominantly paroxysmal AF. However the results for catheter ablation of persistent AF is much lower and more variable, ranging between 20-80%. Moreover there is no agreed-upon standard ablation approach. Prior studies suggest that pulmonary vein isolation (PVI) alone has an unacceptably low success rate so most laboratories supplement this approach with additional lesion sets. These include complex atrial fractionated electrograms ("CAFÉ"), autonomic denervation, and linear left atrial ablation at the roof and mitral isthmus, in an empirical manner or stepwise approach. However, these strategies are time consuming and prone to proarrhythmia, namely post-ablation atrial tachycardias which can occur with an incidence ranging from < 5 to 50%.

The lower efficacy of PVI alone in persistent AF has been attributed to adverse electrical, molecular, and structural remodeling of the atria. Collectively, atrial remodeling decreases conduction velocity and the effective refractory period, and results in a shortened atrial wavelength, which increases the number and stability of reentrant wavelets. This can cause persistence of AF independent of a focal discharge. Standard PVI addresses the "focal discharge" or trigger from the PVs that initiates AF but not necessarily the underlying atrial substrate.

Based on these concepts, we hypothesized that successful atrial reverse remodeling by temporary AAD therapy would facilitate the performance of PVI alone in patients with persistent AF. The utilization of reverse remodeling to enhance the efficiency, efficacy and safety of ablation of AF has not been tested in a randomized clinical trial.

Inclusion Criteria:

• Symptomatic persistent AF
• Failure of class I antiarrhythmic drug or amiodarone to control AF

Exclusion Criteria:

• Previous proarrhythmia to class III AAD including excessive QT prolongation or torsade-de-pointes
• Previous AF ablation procedure
• Congestive heart failure (NYHA III-IV functional class)
• Left ventricle ejection fraction less than 35%
• Left atrial diameter >55 mm
• Unwillingness to participate