Electrophysiological study and catheter ablation
The electrophysiological study (EPS) and ablation procedures were
performed as previously described.11 Catheter ablation
was performed under conscious sedation using dexmedetomidine,
thiopental, and fentanyl. A multipolar catheter with internal
cardioversion (BeeAT, Japan-Life-Line, Tokyo, Japan) was placed in the
coronary sinus through the internal jugular vein, and a deflectable
multipolar catheter was placed in the right ventricle or RA through the
right femoral vein. Transseptal puncture was performed with a
radiofrequency needle (Baylis Medical, Montreal, QC, Canada) under
intracardiac echocardiography guidance, and two sheaths were introduced
into the LA. A deflectable sheath (Agilis, Abbott, St. Paul, MN, USA, or
Vizigo, Biosense Webster Inc., Irvine, CA, USA) and a long sheath
(Swartz SL0 introducer, Abbott) were inserted into the LA. If AF
persisted, defibrillation was performed. During RA pacing (from the high
or lateral RA), a high-resolution LA activation map was created using a
mapping catheter (Pentaray, Biosense Webster). Points were acquired
using the CARTO ConfiDENSE module (Biosense Webster). The preprocedural
computed tomography image of the LA was integrated with a 3D
electroanatomical map. After LA activation mapping was created,
bilateral extensive PVI was performed using a contact force-sensing
radiofrequency catheter (TermoCool SmartTouch SF, Biosense Webster) with
a high-power short-duration (50 w) protocol. The contact force was
controlled at 10–20 g, and the application time was titrated using the
lesion formation index (Ablation Index (AI), Biosense Webster). The
ablation lesions were tagged in a contiguous fashion within a 6-mm
interval (VISITAG, 6-mm diameter setting). The AI was targeted to
500–550 except for 400 along esophageal lesions on the posterior wall
with the limitation of maintaining an esophageal temperature of
<41 oC. The PVI lines were designed by
operators without considering the ECs site. To confirm the completion of
PVI, the bidirectional block of paced or self-activated PV electrograms
was assessed using a 10 or 20 multipolar circular catheter after
ablation of all PVs. If PVI could not be achieved using the originally
designed isolation line, the earliest activation sites inside the
isolation line were ablated. If acute PV reconnections were observed
during the waiting period, the earliest activation sites inside the
isolation line were ablated.