A mathematical model of the membrane action potential of the mammalian ventricular cell is introduced. The model is based, whenever possible, on recent single-cell and single-channel data and incorporates the possibility of changing extracellular potassium concentration [K]o. The fast sodium current, INa, is characterized by fast upstroke velocity (Vmax = 400 V/sec) and slow recovery from inactivation. The time-independent potassium current, IK1, includes a negative-slope phase and displays significant crossover phenomenon as [K]o is varied. The time-dependent potassium current, IK, shows only a minimal degree of crossover. A novel potassium current that activates at plateau potentials is included in the model. The simulated action potential duplicates the experimentally observed effects of changes in [K]o on action potential duration and rest potential. See papers for more and details.
Model Type: Channel/Receptor
Cell Type(s): Heart cell; Cardiac ventricular cell
Model Concept(s): Ion Channel Kinetics; Action Potentials; Pathophysiology; Heart disease
Simulation Environment: XPPAUT
Implementer(s): Wu, Sheng-Nan [snwu at mail.ncku.edu.tw]; Sung, Ruey J
References:
Luo CH, Rudy Y. (1991). A model of the ventricular cardiac action potential. Depolarization, repolarization, and their interaction. Circulation research. 68 [PubMed]
Wu SN. (2004). Simulations of the cardiac action potential based on the Hodgkin-Huxley kinetics with the use of Microsoft Excel spreadsheets. The Chinese journal of physiology. 47 [PubMed]