The left atrium (LA) and pulmonary veins (PVs) are explored through a transeptal approach. Real-time 3D LA maps are reconstructed by using a nonfluoroscopic navigation system. The ipsilateral left and right PVs are encircled in one lesion line by circumferential PV isolation. Radiofrequency energy is delivered at 43°C, 35 W, 0.5 cm away from the PV ostia at the anterior wall, and is reduced to 43°C, 30 W, 1 cm away from the PV ostia at the posterior wall, with a saline irrigation speed of 17 mL/min. Each lesion is ablated continuously until the local potential amplitude decreased by >80% or RF energy deliveries exceeded 40 s. The endpoint of circumferential PV isolation is PV isolation. Additional ablation lines are created by connecting the left inferior PV to the mitral annulus (mitral isthmus) and the roof of the LA between the two superior PVs. After the end of the procedure the implantable loop recorder is implanted in the parasternal area of the chest.