In this randomized study dealing with the ablative treatment of persistent atrial fibrillation, two ablation strategies are compared: a more anatomically guided linear ablation scheme versus an electrophysiological guided focal ablation strategy aiming at the electrical isolating of the pulmonary veins and ablating areas of fragmented intracardiac electrograms thought to maintain atrial fibrillation.

This randomized study deals with two different ablative treatment strategies for persistent atrial fibrillation: a more anatomically guided linear ablation scheme with encircling of the ipsilateral pulmonary veins (PV), a left atrial roof line and an anterior line bridging the anterior mitral anulus to the ostium of the left superior PV versus an electrophysiological guided focal ablation strategy aiming at isolating, electrically, the PV and ablating areas of fragmented intracardiac electrograms thought to maintain atrial fibrillation.

Both ablation approaches contain isolation of the most common source of triggering foci, i.e., the pulmonary veins and additional modification of the substrate maintaining atrial fibrillation.

The study endpoint is a combined efficacy/safety analysis. Extensive follow-up with three-monthly 7 days holter ECG is provided.

Inclusion Criteria:

• age between 18 and 80 years
• symptomatic persistent (> 7 days lasting) atrial fibrillation
• at least one unsuccessful cardioversion or atrial fibrillation relapse in the first 3 months after cardioversion despite antiarrhythmic drug therapy
• oral anticoagulation (> 4 weeks prior to ablation)

Exclusion Criteria:

• moderate to severe valvular heart disease
• congenital heart disease
• LV-EF < 35%
• reversible cause for atrial fibrillation (e.g., hyperthyreosis)
• prior left atrial ablation or Maze operation
• left atrial thrombus