Pentaray catheter

Sinus rhythm was restored by external or internal cardioversion before the PVI, and then a voltage map was created 10 minutes later. If AF did not convert to sinus rhythm, the PVI was performed during AF. After the right or left PVI, external or internal cardioversion was repeatedly administered aiming at the restoration of sinus rhythm. In such a case, voltage mapping was performed after the PVI. Mapping of the LA was performed during sinus rhythm with a 20‐polar Pentaray catheter (Biosense Webster) using the CARTO mapping system and merged with CT integration (CARTOMERGE; Biosense Webster). Five hundred to 1000 LA mapping points per patient were carefully obtained. The band pass filter was set at 30 to 500 Hz. The bipolar peak‐to‐peak voltage at each acquired point was measured. LVAs were defined as those of <0.5 mV and covering >5% of the LA body surface area according to the published data.³, ⁴, ⁵, ⁶, ⁷ The CARTO system automatically calculated the surface area from the manually selected points. To exclude LVAs because of insufficient wall contact, the voltages were reconfirmed by the CF catheter introduced through the long sheath for the sites with apparent LVAs.

The mapping protocol for detection of low-voltage areas is described in detail elsewhere [10 (link)]. Briefly, this was performed during coronary sinus (CS) pacing with a Pentaray catheter (Biosense-Webster [BW], Irvine, CA, USA), acquired with a CONFIDENSE™ module (BW) using CARTO^®3 electroanatomical platform (BW). EGM amplitude ≥ 0.5 mV was defined as normal and <0.5 mV as diseased tissue. All points presenting low voltage were visually inspected and those incorrectly annotated or presenting far-field signals were deleted from the map. Patients presenting AF were cardioverted into sinus rhythm. Only patients who were able to maintain sinus rhythm underwent high density–high resolution LA bipolar voltage mapping.

Mapping and ablation procedures were guided using Ensite Precision (Abbott). A long steerable introducer (Agilis NxT Steerable, 82 cm; Abbott) was used to properly perform the transeptal puncture and electroanatomical mapping of the LA. A PentaRay catheter (20 poles, Biosense Webster) was connected to the pin box of the electrophysiology recording system using a custom-made adaptor. Then, the catheter was positioned sequentially at multiple locations of the endocardium to reconstruct the RA, coronary sinus (CS), and LA anatomy. Eight-second unipolar signals were acquired at each location. Data from the first 4 pigs with PersAF were used to develop a computational tool for in vivo procedures (development group). Twelve more PersAF pigs (ablation group) also underwent a subsequent second biatrial map to assess spatiotemporal stability of drivers. Finally, data were exported for intraprocedural signal processing.