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

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. [Figure: see text] [Figure: see text]