Multi-modal physiological parameter for mapping ablation lesions

Abstract Funding Acknowledgements Type of funding sources: None. Background In addition to variety force time indices, electrophysiologist use peak voltage (Vpp) and or S wave on unipolar electrogram assess RF lesions they deliver. This strategy ignores cardiac conduction speed, direction, curvature, all which are affected by delivered lesion. Electrode array catheters such as the Advisor HD Grid allow individual wavefronts from sites be characterized simultaneously in two dimensions vectorcardiograms can derived. underappreciated attribute electrograms when integrated into activation mapping may provide new insights electrophysiologic state tissue including wavefront amplitude, direction velocity. Objective We tested hypothesis that intracardiac vectorcardiogram loops contain aspects properties better detect compared Vpp reduction a novel multi-modal approach will additional interaction with substrate. Methods 5 ex-vivo Langendorff perfused swine hearts, 56-pole (7 x 8 configuration) electrode arrays were sutured anterior epicardial left ventricle. Unipolar acquired UHN system during programmed stimulation cardinal directions before after creating ablation lesions. Vector loop maps derived orthogonal bipole pairs study organization voltage. Isochrone generated local times. eccentricity was defined for each 4-electrode group function loop’s major minor axis lengths. Low values denote less (more circular). Results An illustrative example vector, isochrone is shown figures 1 2. Pre-ablation conditions show point side slender vector indicative relatively homogeneous linear conduction. contrast, post-ablation much eccentric near ablated area smaller reflecting attenuated amplitude. Interestingly, border zone locations large round observed, suggesting curved nonlinear propagation. Figure 2 shows recorded scar areas diminished size following mean 3.76 vs 2.18mV (p=0.0001) exhibited eccentricity, 0.925 0.848 (p<0.0001), more (eccentricity < 0.7) found (12% 4% pre-ablation, p 0.0001). Conclusions Significant changes characteristics observed even induced attenuation minimal. suggests vectorial information omnipolar Vpp. Wavefront propagation disruption zones thus potentially valuable lesion gaps. along amplitude now map.