Simulation study of electrotonic coupling between human atrial myocytes and mechanosensitive fibroblasts

This study aimed to investigate the effect on adjacent myocyte of fibroblasts (Fbs) with the incorporation of mechano-gated currents induced by mechanical compression (I_ci) of cardiac Fbs. The human atrial myocyte (hAM) was modeled by the Courtemanche-Ramirez-Nattel model. With two different experimentally observed Fbs compression (2μm and 3μm), I_ci was numerically simulated as I_cil and I_cih. They were then incorporated into two types of electro physiological models of human atrial Fbs: passive and active models, respectively. In both passive and active models, lei depolarized the membrane potential of cardiac Fbs. When coupled with passive Fbs, the action potential of myocyte duration at 90% (APD₉₀) was increased in comparison with uncoupled hAM With the incorporation of I_ci into passive Fbs, APD₉₀ of myocyte was further increased. When coupled with active Fbs, similar increases were obtained with the incorporation of both I_ci Furthermore, the resting potential and the maximum value of the action potential of hAM were also increased for both models and with both I_ci. The preliminary simulation study confirmed that mechanosentitive currents in fibroblasts play an important role in mechano-electrical coupling.