 Pulmonary vein isolation PVI will be performed using the Arctic Front Advance cryoballoon ablation catheter. Patients will be randomized to a single cryoballoon application guided by a multipolar recording catheter or to a conventional technique with 2 cryoballoon applications. After cryoballoon ablation of all pulmonary veins, PV conduction block will be assessed by a separate circular mapping catheter. Acute procedural success is defined as complete electrical isolation of a pulmonary vein assessed by entrance and exit block, including 20 minutes waiting time. Complications and duration of the procedure will be assessed. 