Catheter ablation procedure
We discontinued all antiarrhythmic drugs (AADs) ≥ 3 days before
ablation, except for amiodarone, which was stopped ≥ 1 month before.
Patients underwent transesophageal echocardiography (TEE) the day
before the procedure to exclude the presence of thrombi.
Electrophysiological studies and catheter ablation were performed under
intravenous sedation with dexmedetomidine or propofol, with the latter
performed by one of four experienced operators (M.M, T.K, A.S, and Y.M).
Most of the patients underwent radiofrequency catheter ablation.
Cryoballoon ablation was performed for persistent AF of short standing.
Patients with common PVs or a large PV diameter underwent radiofrequency
catheter ablation.
In cryoballoon ablation, an Arctic Front Advance cryoballoon catheter
with a 28-mm balloon size (Medtronic, Inc., Minneapolis MN, USA) was
passed into each PV under guidance by fluoroscopy and the 3-D mapping
system. After confirming PV occlusion by pulmonary venography,
cryoablation commenced and continued for 180 s, during which individual
PVs were isolated. If LA–PV conduction persisted after cryoballoon
ablation, an additional touch-up ablation was performed using an
open-irrigated Thermocool SmartTouch (Biosense Webster) or FlexAbility
(St. Jude Medical) linear ablation catheter with a 3.5-mm tip.
In radiofrequency catheter ablation, circumferential ablation around
both ipsilateral PVs was performed using an open-irrigated Thermocool
SmartTouch (Biosense Webster) or FlexAbility (St. Jude Medical) linear
ablation catheter via an Agilis or Swartz Braided SL0 Transseptal
Guiding Introducer Sheath (St. Jude Medical). Radiofrequency energy was
applied for 30 s at each site using a maximum temperature of 42°C,
maximum power of 35 W, and flow rate of 17 mL/min. PV isolation was
considered complete when the 20-pole circular catheter no longer
recorded any PV potentials.
We
allowed additional ablation procedures in this study as recommended by
the guidelines at the discretion of the operator, such as focal ablation
for reproducible non-PV triggers; ablation of linear lesions, complex
fractionated atrial electrograms (CFAE), and LVA homogenization;
superior vena cava (SVC) isolation; and cavotricuspid isthmus linear
ablation if patients had clinical or induced typical atrial flutter.