A Novel Computational Model of Pacemaker Activity in the Mouse Atrioventricular Node Cell

Nowadays, mathematical modeling has been one of the improvements in technologically advanced science in supporting decision-making in different healthcare scenarios. In the field of numerical modelling of heart electrophysiology, several models of action potential (AP) have been developed for cardiac chambers of different species. The atrioventricular node (AVN) acts as a subsidiary pacemaker and controls impulse conduction between the atria and ventricles. Despite its physiological importance, limited data are available for computing AVN cellular electrophysiology. Further, the ionic mechanisms underlying the automaticity of AVN myocytes are incompletely understood. Only two computational models of AVN have been developed in the last decades (one for rabbit, the other for mouse but without calcium handling). We aimed to develop a new mouse AVN model. We thus build on the preliminary AP mouse AVN model published by Marger et al., which has been updated and improved, by implementing more realistic cellular compartments and calculation of dynamics and handling of intracellular $Ca^{2+}$. The new model reproduces almost all the AVN AP hallmarks and has been used to simulate the effects of blockade of ionic currents involved in AVN pacemaking.