Mapping and Ablation protocol
All antiarrhythmic drugs were discontinued for at least 5 half-lives
prior to ablation. All patients took direct oral anticoagulants (DOAC)
or warfarin for at least 1 month prior to the procedure. Computed
tomography was performed to evaluate the cardiac anatomy.
During the procedure, the surface electrogram and intracardiac
electrograms were continuously monitored and stored on a computer-based
digital recording system. All ablation procedures were performed under
deep sedation with dexmedetomidine hydrochloride, propofol, and
pentazocine. A 100U/kg body weight dose of heparin was administered
after securing the venous line, and the activated clotting time was
maintained at 300 to 350 seconds.
Mapping and ablation were performed under the guidance of a
three-dimensional (3D) mapping system (CARTO3®; Biosense Webster,
Irvine, CA, USA). A duodecapolar catheter (Map-iTTM,
ACCESS POINT, Rogers, MN, USA) was placed into the coronary sinus (CS).
A duodecapolar catheter with five branches (Pentaray®; Biosense Webster,
Irvine, CA, USA) was used to construct a 3D map of the SVC. An
open-irrigated 3.5 mm tip electrode catheter (Thermocool SMARTTOUCH®;
Biosense Webster, Irvine, CA, USA) was utilized for the ablation.