3.2 Ablation procedure
Electrophysiological studies and catheter ablation were performed by
three experienced operators (M.M, T.K, and Y.M) with the patient under
intravenous sedation with dexmedetomidine. The operator performed the
mapping and ablation under guidance with an electroanatomical mapping
system (CARTO 3®). First, PVI was performed using an
open-irrigated ablation catheter (Thermocool
SmartTouch®, Biosense Webster), a cryoballoon (Arctic
Front Advance®, Medtronic, Minneapolis, MN, USA), or a
laser balloon
(HeartLight®,
CardioFocus, Marlborough, MA, USA). Radiofrequency application was set
at 30 W using a dragging technique with a maximum temperature of 42 °C
and an irrigation rate of 17 ml/min. The operator attempted to maintain
an appropriate contact force between the catheter and endocardium of 5
to 20 g. In cases using a cryoballoon, 180-sec freezing was applied. The
laser balloon was inflated with the goal of complete occlusion of the PV
ostium. Laser lesions were created with a 30–50% lesion overlap. Where
very good tissue contact was obtained, maximal power (12 W for 20
seconds) was chosen. At regions with moving blood, laser energy was
applied at 7 W for 30 seconds. PV electrograms were recorded using a
20-pole circular mapping catheter (LassoNaV®, Biosense
Webstar). PVI was considered complete when both entrance and exit blocks
were created.