PO-04-138 FINDING THE SIGNAL TO BURN: OPTIMIZED FRACTIONATION MAPPING FOR IDENTIFYING GANGLION PLEXUSES DURING CARDIONEURAL ABLATION

Abstract

Cardioneural ablation (CNA) is a novel catheter-based technique to treat patients with clinically significant bradyarrhythmia due to cardioinhibitory response in vasovagal syncope (VVS). Three common techniques used to locate areas of ganglion plexuses (GPs) prior to CNA include high frequency stimulation, fractionation mapping (FM), and empiric ablation based on presumed anatomical location of GPs. Optimal intra-procedural diagnostic parameters of fractionation mapping which predict GP location remain ill-defined. To determine the parameters of FM which most precisely locate successful GP ablation sites. Consecutive patients with cardioinhibitory VVS underwent CNA at a single center between March and April 2021. GP sites were targeted with radiofrequency (RF) ablation based on areas demonstrating fractionation, response to high-frequency stimulation, and overall anatomic location. GP sites exhibiting abrupt sinus rate increases with RF delivery were tagged as successful. Following the case, multiple FMs were retrospectively analyzed at 5 sensitivities (range 0.01-0.10 mV), each utilizing 4 combinations of EGMs with width (range 5-10 ms) and refractory interval (range 6-25 ms). Each FM was reviewed and deemed predictive if it identified all successful RF sites without incorrectly annotating sites lacking an RF response. We identified 40 unique FMs for analysis. Setting EGM width to 5 ms and refractory interval to 6 ms predicted all successful ablation sites (positive predictive value [PPV] 100%, p < 0.01). Broadening annotation parameters diminished predictability in a stepwise fashion (5 ms/15 ms, 10 ms/15 ms, 10 ms/25 ms yielded PPV 90%, 70%, 40%, respectively, p < 0.01). Sensitivity settings did not correlate with map utility (PPV 75%, p = 0.98). The optimal fractionation parameters which identified successful ablation sites were those with the narrowest electrogram width and shortest refractory interval. Analysis in a larger cohort is needed to confirm these findings.