Left atrium substrate and wave speed mapping using Omnipolar technology in patients undergoing paroxysmal atrial fibrillation catheter ablation

Abstract Funding Acknowledgements Type of funding sources: None. Background The new Ensite X Cardiac Mapping (Abbott) system, with the introduction of Omnipolar technology (OT), provides three-dimensional information on voltage, direction of activation and conduction velocity of endocardial potentials, regardless of catheter orientation. OT thus enables the creation of more defined voltage maps and a wave speed map, a color map encoded by the numerical value of conduction velocity. Purpose We aimed to evaluate the feasibility and reliability of left atrium (LA) substrate and wave speed mapsperformed with OT in patients undergoing pulmonary vein isolation of paroxysmal atrial fibrillation (AF). Methods We included 39 patients undergoing catheter ablation for paroxysmal AF with the new Ensite X Cardiac Mapping System at five Italian Institution. In all patients the left atrium (LA) was mapped with the Advisor HD Grid catheter (Abbott). A sinus rhythm high-density voltage map and wave speed map were obtained and analyzed to compare low-voltage areas and to identify high conduction velocity areas. Results Thirty-nine pts were included in this analysis (61±10 years, 64% male, 68% with paroxysmal AF, CHA2DS2-VASc = 1.6±1.1, left atrial diameter = 46±9 mm, left ventricle ejection fraction 63±4%). The voltage maps were obtained by acquiring and, after point validation, analyzing significantly more points in the OT analysis than in the bipolar analysis (11455±8833 vs 8186±5826 and 2611±1728 vs 1753±1324, respectively; p < 0.001). Low-voltage area (< 0.05 mV) was significantly less extensive using OT (low-voltage OT area 8.9 cm2 [5.8; 24.2] vs low-voltage bipolar area 10.8 [6.4; 31.4]; p < 0.05), Fig 1. Considering wave speed maps, the pulmonary veins showed significantly higher values than the atrial values (LSPV: 2.89 ms/s ± 1.99; LIPV 2.86 ms/s ± 1.78; RSPV 3.31 ms/s ± 2.07; RIPV 2.86 ms/s ± 1.96; LA 1.67 ms/s ± 0.80; p< 0.001) while, in the atrium, the area of greatest speed was located on the roof (2.35 ms/s ± 1.53; p 0.02) almost drawing a bundle from the RSPV to the LA appendage that could coincide with the anatomical Bachmann’s bundle location, Fig 2. Conclusion OT makes it possible to obtain voltage maps by analyzing a larger number of points and providing a better substrate definition. Wave speed mapping is a promising new map type, allowing characterization and identification of high velocity areas. Further studies are needed to assess the impact of this new technology on procedural workflow and clinical outcome.