PO-691-01 PHYSIOLOGIC, REALISTIC, COMPUTER MODELING OF ATRIAL FIBRILLATION TO FACILITATE THE DEVELOPMENT AND TESTING OF TREATMENT STRATEGIES

Abstract

An interactive, physiologically realistic (PR), and accurate computer simulation allows multiple scenarios to be tested in a “live” environment and has become a key step in the rapid development and testing of treatment strategies for atrial fibrillation (AF). Develop an accurate model of AF that allows the user to define the regions and zones of anisotropic conduction to test the effectiveness of a variety of AF treatment strategies. A model was developed using standard electrophysiologic (EP) parameters established in the literature. An advanced implementation of the Fitzhugh-Nagumo model reproduces the action potential morphology of the human atrium enabling live simulation. To reproduce the complex conduction patterns (CCPs) of AF identified in the EP lab, a bi-layer model was implemented to represent epi- and endocardial dissociation. The model allows a user to define regions of fibrosis, zones of slow conduction, and action potential duration (APD). The user graphically draws these regions and zones with gradients that span entered max and min values of conduction velocity (CV) and APD. The EP lab experience and workflow is reproduced, with CCPs visualized on a 3D anatomy and calculated potentials displayed as 2D traces. To test the CCPs and performance of the model, isolated zones of conduction were delineated on a 3D LA model, with assigned sites of pacing and recording. Model produces accurate atrial CCPs for anatomical meshes > 20k triangles, with expected source-sink block-velocity < 5 cm/s (Figure 1). Regions of anisotropic conduction were applied to match a human AF substrate mapped by Acutus AcQMap, with PVI-block plus 2 anterior, 1 posterior, 1 roof, 1 mitral-isthmus slow conduction zones (0.1 - 50 cm/s); 1 anterior APD zone (65 - 110 ms); and anterior and posterior regions of endo-epi fibrosis (density = 25%, CV = 8 - 25 cm/s). Model produced similar CCPs to human with rotational and pivoting reentry at the same locations (Figure 2). A PR model of AF was developed that allows a user to define regions of fibrosis and zones of conduction abnormalities prominent in AF. The model can be used for developing and testing advanced treatment strategies. Clinical application is feasible, including input of procedural data to achieve optimal treatment strategies.View Large Image Figure ViewerDownload Hi-res image Download (PPT)