After a single procedure of circumferential ablation with PVI and noninducibility, 82% patients did not have recurrence of AF. The inducibility of AF was related to the recurrence of AF. The atrial substrate affected the outcome of the inducibility.

Atrial substrate remodeling with a progressive decrease in the left atrial voltage was demonstrated in patients with recurrent AF.

Structural remodeling of the superior PVs and LA can be reversible after successful ablation without AF recurrence; however, late recurrence of AF is associated with progressive LA dilation.

The 8-mm tip electrodes are more effective than the standard 4-mm length electrodes in linear ablation for typical atrial flutter. This clinical benefit may be of particular value for some patients with broad and/or thick isthmus.

The right atrial foci played an important role in the very late recurrence of AF, whereas the left atrial foci (the majority were PVs) were the major origin of the late recurrence of AF after the catheter ablation of paroxysmal AF.

The LA voltage was lower than the RA, and the atrial voltage correlated with the TAT. Electroanatomical remodeling of the atria could be crucial to the maintenance of AF. The LA substrate properties may play an important role in the recurrence of AF after catheter ablation of AF.

The technique using double multielectrode mapping catheters is a relatively safe and highly effective method for mapping and ablation of focal AF originating from PVs.

The incidence of very late recurrent AF after ablation of paroxysmal AF is very low, and the clinical outcome of patients with very late recurrent AF is benign.