Electromechanical Coupling in Cardiomyocytes Depends on Its Electrotonic Interaction with Fibroblasts: Simulation Study

Cardiac fibroblasts are interspersed within mammalian cardiac tissue. Being mechanically passive they have own changeable membrane potential. They communicate electrically with cardiomyocytes via gap junctions and thus may affect electrical and mechanical activity of the latter This influence may be analyzed in mathematical models. Mathematical models offibroblast-cardiomyocyte interaction developed earlier allow anyone to study only electrical responses of the cardiomyocytes and fibroblasts to their electrical interaction. In this work, we investigated the fibroblast influence on the cardiomyocyte mechanics during afterloaded contractions. In numerical experiments, we observed significant changes in cardiomyocyte action potential duration, isometric force and load-dependent relaxation with an increase in the number of fibroblasts connected with the cardiomyocyte.