The investigators have recently shown that anatomic ganglionated plexi (GP) ablation is inferior to circumferential pulmonary vein (PV) ablation for the treatment of paroxysmal AF. In this study, however, 26% of patients subjected to GP ablation alone without circumferential lesions were free of AF-recurrence up to one year after the ablation procedure. The investigators hypothesized that a combination of circumferential ablation with high-frequency-stimulation-identified GP ablation is superior to conventional circumferential ablation for the prevention of recurrences of paroxysmal atrial fibrillation (AF). The investigators are, therefore, conducting a randomized study comparing conventional circumferential ablation to a combination of circumferential ablation plus specific right and left atrial GP ablation in patients with drug-refractory paroxysmal AF.