Electrophysiologic study and catheter ablation
All antiarrhythmic drugs except for amiodarone were discontinued for at
least five half-lives before the ablation. Warfarin was administered
with a target international normalized ratio of 2.0-3.0 in patients
under 75 years old or 1.6-2.5 in patients 75 years or more for at least
one month before the procedure and continued during the periprocedural
period. Direct oral anticoagulants (DOAC) were used for at least one
month before the procedure and continued during the periprocedural
period except for the procedure morning. The absence of atrial thrombi
was confirmed by transesophageal echography or enhanced computed
tomography. CA was performed under deep sedation using midazolam and
dexmedetomidine. We deployed a multielectrode catheter into the coronary
sinus from the jugular vein and circumferential decapolar electrode
catheter in the pulmonary veins. Boluses of 80 and 50 IU/kg heparin were
administered after venous and transseptal punctures. The activated
clotting time was evaluated at least every 30 minutes and maintained at
≥300 seconds during the procedure. Pulmonary vein isolation was
performed guiding by a circumferential decapolar electrode catheter. We
monitored the surface electrocardiogram (ECG) and bipolar intracardiac
electrograms on a computer-based digital amplifier recording system
(RMC-5000, Nihon Kohden). Ablation was performed with a non-irrigation
catheter (Navistar, Biosense Webster Inc) or irrigated-tip catheter
(SmartTouch, Biosense Webster Inc. or FlexAbility, Abbott). A CARTO
electroanatomical mapping system (Biosense Webster Inc) or Ensite
Velocity system (Velocity Abbott) was used. The endpoint of the ablation
was the complete isolation of all four pulmonary veins (PVs). Whether to
create linear lesions, isolate the superior vena cava, and ablate the
complex fractionated atrial electrograms (CFAEs) and non-PV triggers
were left to the discretion of each operator.