LAUSR

Abstract Funding Acknowledgements Type of funding sources: None. Background Dielectric imaging is used by the KODEX-EPD system to provide information that can be used to guide catheter ablation of cardiac arrhythmia. This includes assessment of catheter-tissue contact (No touch, Touch, or High touch) and local atrial wall thickness (mm). Additionally, the system can detect changes in local dielectric tissue properties to assess the effect of a radiofrequency energy application. This assessment is used to classify ablation points into low or high dielectric response (LDR or HDR), which was designed to indicate the extent of lesion transmurality. Objectives To evaluate the relation between dielectric response and other ablation parameters. Methods The KODEX-EPD system was used to guide ablation in patients with prior pulmonary vein isolation. Ablation included re-isolation of the pulmonary veins and isolation of the superior vena cava if deemed necessary. We downloaded system data from all procedures that were performed with software that provided dielectric response (version 1.5.0, 1.5.0a, 1.5.1 and 1.5.1a) and analyzed the parameters of all individual ablation points. Results The cohort includes 55 patients, in which 135 pulmonary veins and 19 superior venae cavae were targeted. A total of 860 energy applications were applied, resulting in 1458 ablation points. The system classified 31% of ablation points as HDR and 19% as LDR. The system did not provide a dielectric response in 49%. The system’s ability to determine dielectric response was related to the software version(oldest version 71% no DR, newest version 18%) and duration of ablation. High dielectric response (versus LDR or no DR) was multivariably associated with longer energy applications, higher mean ablation power and lower local wall thickness (Table). Mean ablation temperature and impedance drop were not multivariably associated with dielectric response. Conclusion Dielectric response is independently associated with local wall thickness, ablation power and duration, but not with ablation temperature and impedance drop. Newer software versions have reduced the proportion of ablation points for which no dielectric response was provided. Table