Background: Both contact force (CF)-guided radiofrequency ablation (RFA) based pulmonary vein isolation (PVI) and second-generation cryoballoon ablation (CBA) based PVI may improve the procedural outcome. However, the clinical outcome after RFA-and CBA-based PVI remains unclear. Adenosine or adenosine triphosphate (ATP) administration after PVI is useful to detect dormant PV conduction (DC) after the ablation procedure, and the presence of DC has been shown to be related to AF recurrence.Methods: Out of 100 patients with paroxysmal AF (PAF), 50 underwent CF-guided PVI (25-30 W, 30 sec for each ablation: CF-RFA group), and the remaining 50 patients underwent cryoballoon ablation-based PVI (3 min cooling + 2 min bonus cooling for each PV: CBA group). Thirty minutes after PVI, a 30-mg bolus of ATP was administered. We compared the success rate of PVI, and incidence of DC after PVI between the CF-RFA and CBA groups.Results: The subsequent response was assessed for each vein using a ring catheter. In the CBA group, 180 (90%) of 200 PVs were isolated and 20 PVs (10%) (2 left superior PV (LSPV), 3 left inferior PV (LIPV), 4 right superior PV (RSPV), 11 right inferior PV (RIPV) from 14 of 50 patients (28%) required additional RFA because of residual potential at the PV or PV antra. After a waiting period of 30 min after the last energy application, acute PV reconduction was observed spontaneously in 13 PVs (6.5%) (6 LSPV, 3 LIPV, 4 RSPV) from 12 patients (24%) in the CF-RFA group. The DC sites provoked by ATP were 13 PVs (6.5%) (5 LSPV, 3 LIPV, 2 RSPV, 3 RIPV) from 8 patients (16%) in the CF-RFA group, compared with 9 PVs (4.5%) (2 LSPV, 4 LIPV, 1 RSPV, 2 RIPV) from 9 CBA patients (18%) (P = 1.000). AF recurred in 6/50 (12%) in both the CF-RFA and CBA groups at 1 year after the ablation (P = 1.000).Conclusions: There was no significant difference in the incidence of DC after PVI and the 12-month AF-free rate between the second-generation CBA-and CF-based RFA.