A model of the ventricular cardiac action potential. Depolarization, repolarization, and their interaction.

Abstract

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].. The fast sodium current, 'Nap is characterized by fast upstroke velocity (Vma.=400 V/sec) and slow recovery from inactivation. The time-independent potassium current, IKI, includes a negative-slope phase and displays significant crossover phenomenon as [K]

Negative Tension of Scroll Wave Filaments and Turbulence in Three-Dimensional Excitable Media and Application in Cardiac Dynamics

“…Modern ionic models also describe the changes of concentrations of all major ions inside cardiac cells, and generally consist of anywhere between 10 and 60 equations (Luo and Rudy 1991;ten Tusscher et al 2004). The quantitative descriptions of ionic currents in cardiac tissue are continually being revised, and there is not yet general agreement on the best model for all circumstances (ten Tusscher et al 2006).…”

“…The nonlinear terms are typically stiff and the integration is slower than in the previous cases. Most results on scroll wave dynamics in ionic models here will be illustrated with the Luo-Rudy model phase 1 (LR1) (Luo and Rudy 1991). It describes the biophysical mechanism of generation of action potential in cardiac cells by a relatively small number of state variables and was widely used to study wave propagation in 2D and 3D cardiac tissue.…”

“…In most simulations presented here, the original values of the parameters given in Luo and Rudy (1991) were used, except for G Na and G si , which were varied in simulations (in Luo and Rudy 1991 G Na = 23 mS/cm 2 and G si = 0.09 mS/cm 2 ). Note that G Na controls the speed of the waves (Alonso and Panfilov 2007) and in a general sense the excitability of the tissue, and G si is responsible for the front-tail interaction between the pulses.…”

Cardiac cell modelling: Observations from the heart of the cardiac physiome project

“…Along with human ventricular models, which are discussed in detail below, ventricular models have been developed for guinea pig (Luo and Rudy 1991, Nordin 1993, Luo and Rudy 1994, Noble et al 1998, Faber and Rudy 2000, canine , Fox et al 2002, Greenstein and Winslow 2002, Cabo and Boyden 2003, Hund and Rudy 2004, Flaim et al 2006, rabbit (Puglisi and Bers 2001, Shannon et al 2004, Mahajan et al 2008, rat (Pandit et al 2001), and mouse (Bondarenko et al 2004, Wang andSobie 2008). The existence of species-specific ventricular models is a significant improvement over earlier, more generic ventricular models and recognises the differences in current contributions across species.…”

Modelling the heart: insights, failures and progress

“…Although this was directed towards atrial cells, it also provided a basis for modelling ventricular cells in species (rat, mouse) with short ventricular action potentials, and many of its features were adopted in later ventricular cell models of species with high plateaus. (34)(35)(36)(37)(38) The Hilgemann-Noble model addressed a number of important questions concerning calcium balance:…”