Po-03-099 use of novel omnipolar mapping in slow pathway localization and ablation of atrioventricular nodal re-entrant tachycardia

Precise localization of the slow atrioventricular nodal pathway (SP) is crucial to safe and successful ablation of atrioventricular nodal re-entrant tachycardia (AVNRT). However, interpatient anatomic variability can limit ablation efficacy and increase risk for heart block. Activation mapping in sinus rhythm using omnipolar technology (OT) can delineate areas of abrupt change in propagation direction, which may reflect connections between fast and slow pathways of the AVN (Fig 1). As such, OT may offer a novel way to identify the SP and guide ablation of AVNRT. To correlate potential SP ablation sites identified with OT mapping to those identified via traditional methods and to compare procedural outcomes between AVNRT ablations performed with and without OT mapping. We retrospectively evaluated patients undergoing first-time AVNRT ablation using the EnSite X EP mapping system (Abbott, IL). In all cases, AVNRT was induced and confirmed as the primary clinical arrhythmia through diagnostic pacing maneuvers. In cases utilizing OT, activation maps of the Triangle of Koch were created using the Abbott HD Grid mapping catheter in sinus rhythm and evaluated retrospectively to identify the location of propagation “pivot points.” These were compared with sites of successful SP ablation, where delivery of radiofrequency energy resulted in rapid onset of slow junctional rhythm. Procedural metrics were compared between cases with and without use of OT. Of 12 total patients, 5 underwent activation mapping using OT. Two in the OT group had atypical and the remaining 10 had typical AVNRT. In cases utilizing OT, pivot points correlated with and were located at a median of 2mm (IQR 0-3) from sites of successful SP modification. Comparing cases using and not using OT, an average of 6.8+1.9 and 8.3+8.3 total ablation lesions with 138+43 and 296+269 seconds of total ablation time were delivered, respectively. Procedure times were similar between OT and non-OT cases (131+23 vs. 115+52 minutes) despite longer duration of mapping in OT than in non-OT cases (18+11 vs. 8+4 minutes), likely due to shorter ablation time. Activation mapping in sinus rhythm using OT may facilitate efficient and effective localization and ablation of the SP in AVNRT. Further investigation is needed to validate its exact utility and role.