Impact of electrode orientation, myocardial wall thickness, and myofiber direction on intracardiac electrograms: numerical modeling and analytical solutions

Frontiers in Physiology

Physiology

Hans Dierckx¹  Lore Leenknegt¹  Alexander V. Panfilov² 

[1] Department of Mathematics, KU Leuven Campus KULAK, KU Leuven, Kortrijk, Belgium;iSi Health–KU Leuven Institute of Physics-based Modeling for In Silico Health, KU Leuven, Leuven, Belgium;Department of Physics and Astronomy, Ghent University, Ghent, Belgium;

关键词: bidomain;    EGM;    modeling;    simulations;    openCARP;    solid angle;   

DOI  :  10.3389/fphys.2023.1213218

 received in 2023-04-27, accepted in 2023-06-14,  发布年份 2023

来源: Frontiers

【 摘 要 】

Intracardiac electrograms (iEGMs) are time traces of the electrical potential recorded close to the heart muscle. We calculate unipolar and bipolar iEGMs analytically for a myocardial slab with parallel myofibers and validate them against numerical bidomain simulations. The analytical solution obtained via the method of mirrors is an infinite series of arctangents. It goes beyond the solid angle theory and is in good agreement with the simulations, even though bath loading effects were not accounted for in the analytical calculation. At a large distance from the myocardium, iEGMs decay as 1/R (unipolar), 1/R2 (bipolar and parallel), and 1/R3 (bipolar and perpendicular to the endocardium). At the endocardial surface, there is a mathematical branch cut. Here, we show how a thicker myocardium generates iEGMs with larger amplitudes and how anisotropy affects the iEGM width and amplitude. If only the leading-order term of our expansion is retained, it can be determined how the conductivities of the bath, torso, myocardium, and myofiber direction together determine the iEGM amplitude. Our results will be useful in the quantitative interpretation of iEGMs, the selection of thresholds to characterize viable tissues, and for future inferences of tissue parameters.

【 授权许可】

Unknown   
Copyright © 2023 Leenknegt, Panfilov and Dierckx.