B-PO05-078 THE NOVEL USE OF OMNIPOLAR ELECTROGRAMS TO PERFORM VOLTAGE MAPPING IN PATIENTS UNDERGOING CATHETER ABLATION FOR ATRIAL FIBRILLATION

Abstract

Current mapping for atrial substrates in patients with a history of atrial fibrillation (AF) relies on bipolar peak-to-peak voltage mapping of the atria. This is limited by its use of conduction direction during recording which may cause errors in demarcating low voltage areas and false-positives when assessing for PV isolation post-procedure. We have developed a novel approach, omnipolar (OTmax) mapping, providing signals independent of catheter-orientation but using the greatest possible voltage. The objective was to compare OT mapping with bipolar mapping in imaging low voltage areas (LVA) in the atria in patients undergoing catheter ablation for AF. All patients undergoing first-time catheter ablation using the EnSite PrecisionTM mapping system (Abbott, St. Paul, MN, USA) between 04/2019 - 09/2020 underwent HD mapping with AdvisorTM HD Grid Mapping Catheter, Sensor EnabledTM. Mean voltage and percentage of electrical points non-LVA (clinical benefit proportion, CBP) were compared between OT mapping and bipolar mapping recorded from two adjacent electrodes along the catheter (BiAlong), across the catheter (BiAcross) and maximum adjoining electrograms (BiMax). Cluster bootstrap resampling method estimated standard errors for CBP and mean voltage difference. Among 51 patients, the mean age was 64±10 years and 64% were male. OTMax mapping had higher voltage recorded versus all bipolar modalities at all voltage thresholds. The mean voltage differences between OTMax and all other bipolar configurations were greatest at higher voltages and significant at all levels. Overall, differences to OTMax mapping voltages were highest when compared to BiAcross: Mean(SE): 0.68(0.05), 95% CI: 0.56-0.81, p<0.001, followed by BiAlong: Mean(SE): 0.67(0.05), 95% CI: 0.55-0.80, and then BiMax Mean(SE): 0.24(0.02), 95% CI: 0.21-0.28. The proportion of tissue not regarded as LVA was higher for OTmax compared to all bipolar modalities irrespective of the voltage threshold. OT mapping was superior to bipolar mapping modalities in identifying atrial LVAs in patients undergoing catheter for AF. These findings provide a more detailed understanding of potential targets for the catheter ablation of AF.