Session P95.3

HPC Simulations for the Study of Propagation Dynamics in Realistic Heart Models

MO Bernabeu*, MJ Bishop, V Grau, B Rodríguez

University of Oxford
Oxford, UK

Information regarding the propagation dynamics of intramural electrical activation wavefronts is thought to be critical in gaining a better understanding of cardiac function in both healthy and pathological conditions. However, the way in which wavefronts interact with, and propagate through, heterogeneous regions of tissue has not been thoroughly assessed due to limitations in the detail and complexity of current whole ventricular models.
The goal of this study is to develop the techniques to build realistic, highly-detailed and personalised whole ventricular models directly from high-resolution MR images for use within a reliable, fully tested cardiac simulation software to investigate the role of individual tissue heterogeneity on intramural wavefront dynamics.
To achieve this goal, a realistic anatomically accurate finite element ventricular model was constructed directly from a high-resolution (resolution˜25µm3), 3D rabbit MRI dataset. The images were automatically segmented using a combination of level-set techniques and tetrahedral meshes were generated using the Delaunay algorithm. The model includes detailed structural information including blood vessels, papillary muscles, trabeculations and a representation of realistic fibre orientation.
Propagation of electrical activation within the realistic rabbit ventricular model was simulated by solving the bidomain equations using CHASTE, a novel biological simulation environment. CHASTE has been developed using state-of-the-art numerical and computational techniques, as well as professional software engineering practices, and provides a rigorously-tested library of computational biology software.
The results of this study successfully demonstrate the ability of our developed pipeline in generating individualised high-resolution cardiac models to directly assess the specific impact of complex structural geometry, fibre orientation, blood vessels and other heterogeneities on intramural wavefront dynamics. Simulations show that the inclusion of such heterogeneities within cardiac models significantly affects the local orientation of activation wavefronts within the ventricular walls. Such findings may have significant impact in the understanding of basic cardiac function and arrhythmias mechanisms, and in the development and application of the next generation of cardiac models.

(Abstract Control Number: 271)