A Computational Model of Electrophysiological Properties of Cardiomyocytes
Abstract
Introduction. The method of electrical analogies for the analysis of bioelectric dynamic processes in cardiomyocytes is used in the study. This method allows for replacing investigation of phenomena in non-electrical systems by research of analogous phenomena in electrical circuits. The investigation of time processes in cardiac cells is based on the solution of the system of ordinary differential equations for an electrical circuit. Electrophysiological properties of cardiomyocytes such as refractory period, maximum capture rate and electrical restitution are studied. Mathematical modeling. Computational simulation of the action potential and currents for $K^+$, $Na^+$, $Ca^{2+}$ ions in cardiomyocytes is performed by using the parallel conductance model. This model is based on the assumption of the presence of independent ion channels for $K^+$, $Na^+$, $Ca^{2+}$ ions, as well as leakage through the membrane of cardiac cell. Each branch of the electrical circuit reflects the contribution of one type of ions to total membrane current. Results. The obtained electrical restitution curves for ventricular and atrial cardiomyocytes are presented in the paper. The proposed model makes it possible to identify the areas with the maximum slope on the restitution curves, which are crucial in the development of cardiac arrhythmias. Dependences of calcium current on stimulation frequency for atrial and ventricular cardiomyocytes are obtained. Analysis of the kinetics of calcium ions under various protocols of external influences can be useful for predicting the contractile force of cardiomyocytes. Conclusion. The results of calculations can be used to interpret the experimental results obtained in investigations of cardiomyocytes using the "laboratory on a chip" technology, as well as in the design of new experiments with cardiomyocytes for drug screening, cell therapy and personalized studies of heart diseases.
Keywords
