2.4 Ablation procedure and confirmation of LAPWI
LAPWI was performed after confirmation of bilateral PVI. RF energy was
applied for 15 seconds with a 3.5-mm open-irrigated-tip catheter
(Navistar ThermoCoolSmartTouch SF; Biosense Webster) set at an upper
temperature limit of 43°C, a saline irrigation flow rate of 17–30
mL/min (CoolFlow Pump; Biosense Webster), and output power of 45 W. In
all cases, automated ablation lesion tagging based on catheter stability
information (VisiTag Module, CARTO3) was used, but the RF delivery time
was not guided by AI. The RF power output was reduced to 25–35 W when
the esophageal temperature rose, and RF energy delivery was terminated
if the probe-monitored esophageal temperature reached 40°C. Complete
LAPWI was confirmed by bidirectional block. At least 30 minutes after
the procedure, 30 mg of adenosine triphosphate (ATP) was injected to
confirm persistent roof and floor line block.14
If the first-pass LAPWI failure or if
acute LAPW reconnection, defined
as spontaneous reconnection or dormant conduction provoked by ATP, was
seen after LAPWI was attempted, the segment with a gap in the block line
was identified by the PentaRay catheter; noted as a right, center, or
left segment; and subjected to additional RF energy application.
Successful first-pass LAPWI was
defined as complete LAPWI (absence of acute LAPW reconnections) achieved
during the initial RF applications.