Velocity Field Analysis of Activation Maps in Atrial Fibrillation A Simulation Study

摘要

New multispline mapping systems are now available for the study of atrial fibrillation, which aim at the identification of localized arrhythmic sources. Nevertheless quantitative methods for the analysis of these data are still lacking. In this paper a new method to identify arrhythmic sources, based on the quantitative characterization of the velocity vector field in the mapping area, is proposed and validated in a simulation model. The algorithm reconstructed the activation process by radial basis function (RBF) interpolation of the discrete activation times obtained from the Pen (a Ray mapping system. Following interpolation the velocity vector field and its divergence were analytically determined. RBF interpolation proved to be flexible to reconstruct different simulated activation patterns, including ectopic foci and wavefront collision, and reliable even when part of the mapping sites was not available. Divergence analysis was effective to locate and characterize the peculiar features of arrhythmic activation patterns, identifying ectopic foci as sources of the vector field and collision lines as sinks. Although preliminary, the presented results suggest the potentialities of vector field analysis as a quantitative tool to identify localized arrhythmic sources and clarify arrhythmia mechanisms, thus optimizing the ablative treatment of atrial fibrillation.