Introduction - Pulmonary vein isolation (PVI) is the cornerstone of paroxysmal atrial fibrillation (AF) ablation. Recurrences remain, however, not infrequent and are mainly due to PVs reconnection. In this setting, all procedural means able to improve the quality of tissue lesions are welcome.

Study Hypothesis - A continuous sensing of contact force (CF) during ablation, offered by a new catheter available on the market, was a valuable additional tool increasing the efficacy of the ablation procedure for PVI.

Methods - Prospective observational non-randomized monocentric study. Patients with paroxysmal AF receive PVI following standard ablation procedures (linear antral catheter ablation guided by CARTO 3 System, Biosense Webster, Inc.) using either a new irrigated RF ablation catheter that provides tip-to-tissue CF information (THERMOCOOL SMARTTOUCH Catheter, Biosense Webster, Inc.) (CF group), or a non-CF irrigated catheter (THERMOCOOL SF or EZ STEER THERMOCOOL Catheter, Biosense Webster, Inc.) (control group). Overall, 60 consecutive patients are enrolled in the study, with 30 patients in each group. All procedures is performed by the same experienced operator, not blinded to the catheter used. Except for CF information (with an objective of at least 10 g, associated to the most perpendicular vector obtainable), ablation procedures are carried out using identical approaches in both groups. Patients are discharged from hospital free of antiarrhythmic therapy. Patients are enrolled in a specific follow-up plan.

Primary Endpoints -(1) Proportion of PVI after exclusive anatomic approach, (2) Proportion of patients free of AF after 12-month follow-up.

Inclusion Criteria:

• Symptomatic paroxysmal atrial fibrillation despite at least failure of one anti-arrhythmic drug
• Age 18-75 yrs
• First catheter ablation

Exclusion Criteria:

• Left ventricle ejection fraction at echocardiography <50%
• History of heart surgery

Study population included patients with paroxysmal atrial fibrillation who undergo a first catheter ablation procedure (pulmonary vein isolation).