Automated Intraprocedural Localization of Origin of Ventricular Activation Using Patient-Specific Computerized Tomography Imaging

Abstract Background To facilitate catheter ablation of VT, we have previously developed an automated method to identify sources of LV activation in real time using 12-lead ECG, the accuracy of which depends on acquisition of a complete electroanatomic (EA) map. Objective To assess feasibility of using a registered cardiac CT rather than EA map to permit real-time localization and avoid errors introduced by incomplete maps. Methods Prior to LV VT ablation, 10 patients had CT imaging and 3D reconstruction of the cardiac surface to create a triangle mesh surface, which was registered to the EA map during the procedure and imported into the custom localization software. The software uses QRS integrals from leads III, V2, V6, derives personalized regression coefficients from pacing at ≥5 sites with known locations, and estimates location of unknown activation sites on the 3D patient-specific LV endocardial surface. Localization accuracy was quantified for VT-exit sites in millimeters by comparing the calculated against the known locations. Results The VT-exit site was identified for 20 VTs using activation and entrainment mapping, supplemented by pace-mapping at the scar margin. The automated localization software achieved incremental accuracy with additional pacing sites and had a mean localization error of 6.9 ± 5.7 mm for the 20 VTs. Conclusions Patient-specific CT geometry is feasible for use in real-time automated localization of ventricular activation and may avoid reliance on a complete electroanatomic map.