2.2 Pre-ablation preparation protocol
Prior to the procedure, all antiarrhythmic drugs were discontinued for
at least 5 half-lives. Direct oral anticoagulants were changed to
dabigatran from the day before the ablation. Patients on warfarin
continued taking it during the peri-procedural period. An international
normalized ratio level between 2.0 and 3.0 was considered acceptable.
All patients continued taking anticoagulants throughout the
peri-procedural period. Using prone-positional enhanced computed
tomography or intracardiac/transesophageal echocardiography, we
confirmed that there were no intracardiac thrombi before the ablation.
Surface electrocardiograms and bipolar intracardiac electrograms
filtered from 30 to 500 Hz were monitored.
Ablation was performed under general anesthesia with dexmedetomidine,
thiopental, and rocuronium. The ablation procedure has been previously
described in detail.15 Briefly, a standard transvenous
approach was employed for transseptal puncture and subsequent PV
isolation. A 7-Fr 20-pole three-site mapping catheter (BeeAT; Japan
Lifeline, Tokyo, Japan) was located in the coronary sinus for anatomic
guidance. With a radiofrequency needle (Baylis Medical, Montreal, QC,
Canada), a single transseptal puncture of the fossa ovalis was performed
using the Brockenbrough technique. The puncture was guided by
intracardiac echocardiography (ACUSON AcuNav; Biosense Webster, Diamond
Bar, CA, USA) and biplane fluoroscopy (right and left anterior oblique
projections). Thereafter, heparin was administered intravenously to
achieve an activated clotting time between 300 and 350 seconds during
the ablation procedure.