RF Ablation Procedure
Procedures were performed under general anesthesia and as per usual
protocol. Percutaneous access was obtained from the right femoral vein
for all catheters. Intravenous heparin was administered to maintain an
activated clotting time of approx. 350s. Transseptal puncture was
performed under ICE and fluoroscopy guidance using the NRG Transseptal
Needle (Baylis Medical, Montreal, Canada) with the TorFlex Transseptal
Guiding Sheath (Baylis Medical) or SL-1 Transseptal Guiding Introducer
(Abbott, ). 3D electroanatomic mapping (EnSite Precision Mapping System,
Abbott) was used for catheter guidance and CF measurement. Attempts to
stabilize the ablation catheter were limited to the choice of steerable
sheath. The Agilis NxT (Abbott, Chicago, IL) or SureFlex steerable
sheath (Baylis Medical) were used to position the ablation catheter
(TactiCath Contact Force Ablation Catheter, Abbott) for point-by-point
ablation using approx. 50W RF energy and a target contact force of
10-15g until an impedance drop of approx. 10Ω was achieved. The left
superior and inferior PVs (LSPV and LIPV, respectively) were isolated
before attempting to isolate the right superior and inferior PVs (RSPV
and RIPV, respectively). Esophageal temperature was monitored during the
ablation to remain below approx. 38oC. Acute PV
reconnection was assessed by monitoring electrocardiograms (ECG) and
voltage maps for re-appearance of PV potentials within an approx.
10-minute wait time. ECG was performed during follow up of at least 6
months to assess recurrence of symptoms and long-term procedural
outcomes.