Patient population
We identified 53 consecutive patients at a single experienced
electrophysiology center who underwent first time RF ablation for
persistent AF. Of these, 27 were cardioverted then mapped and ablated in
sinus rhythm with atrial pacing, and 26 were mapped and ablated in AF
with ventricular pacing. Pacing was performed at a cycle length of
500-600ms, regardless of pacing site. All procedures were performed
under general anesthesia with high frequency jet ventilation.
Electroanatomical mapping was performed using either the circular
Lasso® or five-spine PentaRay®mapping catheter and the CARTO3® mapping system,
version 4 (Biosense Webster Inc., USA). Radiofrequency ablation was
performed using the ThermoCool SmartTouch®force-sensing catheter (Biosense Webster Inc., USA) using point-by-point
ablation at a power of 50W. All patients underwent pulmonary vein
isolation (PVI) via wide antral circumferential ablation of the left and
right pulmonary veins, as well as posterior wall isolation (PWI) via
superior and inferior posterior wall lines connecting the PVI lesion
sets. Additional ablation of the left and right carinas and/or residual
electro-active areas within the posterior wall were performed at the
discretion of the operator. VisiTag lesion stability settings were set
to 2mm and 5s. Electrical isolation, including entrance and exit block,
was confirmed using differential pacing and adenosine administration.