We included 20 patients with AF ( 65 % male , 60.110.5 years old , 80 % persistent AF [ PeAF ] ) who had undergone empirically-based catheter ablation : circumferential pulmonary vein isolation ( CPVI ) for paroxysmal AF ( PAF ) and additional posterior box lesion ( L1 ) and anterior line ( L2 ) for PeAF .