Estimation of the Ablated Area size based on Local Conduction Velocity Simulations and animal experiments

Abstract

Estimation of the radiofrequency ablated (RFA) area size, local conduction velocity (CVL), and general electrophysiology at the ablation sites remains a challenge in clinical electrophysiology. This study proposes a circle method (CM) for estimation of local CV vector fields, applied to identify late activation zones, and for localization and characterization of ablated tissue. The method is based on automatic detection of the wavefront propagation direction calculated along directions in circular disposition. The method robustness is tested and validated to estimate the electrophysiological effects and lesion sites after RFA ablation. RFA was modeled in simulations and performed in isolated hearts. Local CV at the center of the ablation area showed a logarithmic curve increasing with larger radius, suitable for estimating the ablated area size. From the CVL maps, distinct regions of substantially lower CVLs showed the ablated area's location. Maps of CVL directions around the ablated area show characteristic deviation symmetric regarding the propagating wavefront allowing for more accurate delineation of ablated area. The method is validated for different ablation geometries and sizes, wavefront curvatures and different animal experiments. Estimation of ablated area's size and its location could be performed without prior knowledge of the wavefront propagation direction.