Ablation Procedure
In paroxysmal AF patients, pulmonary vein isolation (PVI) was performed
using either cryo-balloon ablation (CBA, single short freezing for 180
sec in each PV) or radiofrequency catheter ablation (RFCA) in the first
session. RFCA was selected in patients with common PV or large PV ostium
(>28mm) based on the LA/PV anatomy evaluated by
cardiac-computed tomography imaging before the procedure. In persistent
AF patients, only RFCA was used for PVI in the first session. In all
patients, only the PVI strategy was used for the first AF ablation and
no additional linear ablation in the LA was performed; only
cavotricuspid isthmus ablation was permitted for documented typical
atrial flutter. In the second session for both types of AF, the
incomplete line of PVI was repaired with RFCA if necessary, and
additional linear ablation at the roof and bottom between left and right
PV (posterior wall isolation) and superior vena cava isolation were
performed.
The CBA procedure was achieved using electro-anatomical mapping (EnSite
NavX, Abbott, St. Paul, MN, USA) and fluoroscopic guidance to position
the cryo-balloon catheter. In the RFCA procedure, PVI was achieved using
a focal “point-by-point” catheter approach, delivering radiofrequency
energy to the cardiac tissue with irrigation tip catheters
(THERMOCOOL SMARTTOUCH® SF,
Biosense Webster, Diamond Bar, CA, USA [target contact force: 10-20g,
RF time: 30-60 sec, irrigation flow rate: 8 ml/min for ≤30W, 15 ml/min
for >30W, power control mode], or
FlexAbilityTM, Abbott, St Paul, MN, USA [RF time:
30-60 sec, irrigation flow rate: 10 ml/min for <38℃, 13 ml/min
for ≥38℃, temperature control mode]). RFCA lesion sets encircled the
PV antra using electro-anatomical mapping (CARTO3, Biosense Webster,
Diamond Bar, CA, USA or EnSite NavX, Abbott, St. Paul, MN, USA) and
fluoroscopy guidance.
All procedures were performed under sinus rhythm; internal (3-35J) or
external (50-220J) electrical cardioversion was performed with gradually
increasing shock intensity to restore sinus rhythm when AF was observed
before/during the procedure.