Comparison of Propagation Models and Forward Calculation Methods on Cellular, Tissue and Organ Scale Atrial Electrophysiology

Abstract

The bidomain model and the finite element method are an established standard to mathematically describe cardiac electrophysiology, but are both suboptimal choices for fast and large-scale simulations due to high computational costs. We investigate to what extent simplified approaches for propagation models (monodomain, reaction-Eikonal and Eikonal) and forward calculation (boundary element and infinite volume conductor) deliver markedly accelerated, yet physiologically accurate simulation results in atrial electrophysiology. Methods: We compared action potential durations, local activation times (LATs), and electrocardiograms (ECGs) for sinus rhythm simulations on healthy and fibrotically infiltrated atrial models. Results: All simplified model solutions yielded LATs and P waves in accurate accordance with the bidomain results. Only for the Eikonal model with pre-computed action potential templates shifted in time to derive transmembrane voltages, repolarization behavior notably deviated from the bidomain results. ECGs calculated with the boundary element method were characterized by correlation coefficients >0.9 compared to the finite element method. The infinite volume conductor method led to lower correlation coefficients caused predominantly by systematic overestimations of P wave amplitudes in the precordial leads. Conclusion: Our results demonstrate that the Eikonal model yields accurate LATs and combined with the boundary element method precise ECGs compared to markedly more expensive full bidomain simulations. However, for an accurate representation of atrial repolarization dynamics, diffusion terms must be accounted for in simplified models. Significance: Simulations of atrial LATs and ECGs can be notably accelerated to clinically feasible time frames at high accuracy by resorting to the Eikonal and boundary element methods.

A Review of Personalised Cardiac Computational Modelling Using Electroanatomical Mapping Data

“…[71][72][73][74] Reduced-order models: another type of model is reduced order versions of the full order bidomain equations. 75,76 For example, eikonal models are based on macroscopic kinetics of the EP wavefront propagation and provide an efficient way of computing arrival times of depolarisation wavefronts in the myocardium. Variants of the eikonal type models that have been used in personalised models include reaction-eikonal and diffusion-reaction-eikonal.…”

Personalized Modeling of Atrial Activation and P-waves: a Comparison Between Invasive and Non-Invasive Cardiac Mapping

“…For the forward calculation of virtual P-waves, extracellular potentials on the body surface were recovered using openCARP [14] from the same 6 previously selected electrode locations. The atria were assumed to be immersed in an infinite volume conductor [15]. Simulated P-waves were low-pass filtered with a cutoff frequency of 40 Hz and then individually amplified to match the maximum amplitude of their corresponding measured P-wave per lead.…”