The knowledge of the real-time contact force leads to a greater reduction in atrial fibrillation burden after pulmonary vein antrum isolation.

A randomized controlled study comparing pulmonary vein antrum isolation with and without the knowledge of the real-time contact force. In both groups, a catheter, which is able to measure contact force (SmartTouch, ThermoCool catheter, Biosense Webster) will be used. In the control group, the operator will be blinded to the measured contact-force. In all patients, the ablation will be guided by a circumferential mapping catheter (Lasso, Biosense Webster), CARTO 3 mapping system and ablation of adenosine-induced reconnection will be performed in all patients. Follow-up will be performed by continuous monitoring using an implantable loop recorder (Reveal XT, Medtronic Inc, Minneapolis, Minn)

Inclusion Criteria:

• Patients <75 years of age with atrial fibrillation who have had at least two episodes of symptomatic paroxysmal or short-lasting persistent atrial fibrillation in the foregoing 12 months undergoing the first pulmonary vein antrum isolation can be included.
• Patients having also persistent episodes of atrial fibrillation of shorter duration (the longest atrial fibrillation episode 3 months) on top of paroxysmal episodes will be included

Exclusion Criteria:

• Contraindication to anticoagulation treatment with vitamin K antagonists Amiodarone therapy Expected surgery for structural heart disease within the follow-up period Significant mitral valve disease NYHA III-IV Left ventricular ejection fraction < 35% Left atrial diameter > 5 cm Secondary atrial fibrillation (e.g. post-surgery, infections, hyperthyroidism) Age < 18 years