Procedure
In all patients, the procedure was performed under deep sedation with a
continuous intravenous infusion of dexmedetomidine hydrochloride
(Precedex) and additional boluses of midazolam and thiamylal. Esophageal
temperature was monitored throughout the procedure; temperature limit
was set to 41℃. If a patient showed AF rhythm in the
electrophysiological laboratory, electric cardioversion was performed to
restore sinus rhythm.
A bolus of 5,000–10,000 international units of unfractionated heparin
(100-150 U/kg) was administered before trans-septal puncture to achieve
activated clotting time (ACT) >300 sec. ACT was measured
every 20 min after the first heparin shot and additional heparin boluses
were administered to maintain the ACT >300 sec. A decapolar
catheter was advanced into the coronary sinus via the internal jugular
vein. An 8Fr ICE catheter (SoundStar, Biosense Webster, Diamond Bar, CA,
USA) was inserted into the right atrium (RA) via a 10Fr short sheath in
the right femoral vein; trans-septal puncture was performed under ICE
guidance. Two 8Fr long sheaths (SL1; Abbott, St. Paul, MN, USA) and a
8.5Fr deflectable sheath (Agilis NxT, [short size 61 cm], Abbott,
St. Paul, MN, USA) were then advanced into the LA. A ring-shaped
decapolar catheter (LASSO® eco catheter, Biosense Webster, Diamond Bar,
CA, USA) and a multielectrode catheter (PENTARAY® eco catheter, Biosense
Webster) were used for mapping. CARTO V6 (Biosense Webster) was used to
create a 3-dimensional electro-anatomical voltage map of the LA and to
integrate the voltage map with the CT imaging reconstruction of the LA
(CartoMerge, Biosense Webster). The contrast fluoroscopy image of the LA
was obtained and combined with the reconstructed CT image by CARTOUNIVU™
Module (Biosense Webster).