Abstract 17013: Voltage Resolution of Standard Bipolar and Omnipolar Ventricular Electrograms

Introduction: Standard bipolar voltage (BiV) mapping is dependent on bipole axis orientation compared to the direction of the activation wavefront. In contrast, omnipolar mapping technology (OmniT) allows for direction-independent voltage measurement, yielding a maximum for each site sampled. However, it is unclear if normal voltage values are the same for BiV and OmniT. Hypothesis: To determine whether electrical signal obtained with OmniT are greater than BiV, using a single 4x4 grid array catheter (HD Grid) inserted in the left ventricle (LV) of an experimental animal. Methods: HD Grid consists of 4 splines, allowing for orthogonal bipoles along (AL) a single spline and across (AC) adjacent splines, allowing for simultaneous OmniT and BiV evaluation. Animals (n=3) underwent transseptal LV mapping during sinus rhythm (SR) and right ventricular pacing (RVP) using HD Grid (4mm interelectrode spacing). Abbott Precision research software was used to generate electroanatomic maps. Peak-to-peak voltage data for OmniT and BiV, both along and across the splines, were exported to a spreadsheet. Data were normalized via log transformation and compared with t-test. Results: Mean voltages and 95% confidence interval for OmniT were consistently greater than BiV AL and AC for both SR and RVP (p<0.05), while BiV AL and AC were comparable. No difference was seen when comparing each method during SR and RVP. The absolute BiV difference due to orientation was significant. See Table. Conclusions: Amplitude of OmiT electorgrams are greater with respect to BiV, which is consistent with the ability of omnipolar technology to capture maximal signals independently from waveform direction. This should be taken into account when determining the optimal OmniT value for ventricular scar.