Sixty patients will be randomized to select right or left pulmonary veins whether to apply contact force-guided ablation or contact force-blinded ablation strategy. Each PV will be ablated with same contact force-sensing catheter (Thermocool Smart Touch Catheter, Biosense Webster Inc. CA). The PV (right or left) which will be randomized to contact force-sensing PV or blind PV. Contact force-sensing PV will be ablated guided by contact force, whereas the blind PVs will be ablated without contact force-sensing information. The change of impedance, total ablation and time to ablate PV will be collected and analysed according to contact force-sensing strategy. After exit and entrance block by conventional method, dormant conduction will be evaluated by using adenosine. The proportion of dormant conduction will be compared between contact force-sensing guided or blinded strategy.