Fenton-Karma model. Temporal dynamics

A simplified ionic model with three membrane currents that approximates well the restitution properties and spiral wave behavior of more complex ionic models of cardiac action potential (Beeler-Reuter and others) was introdused in [1].
    du/dt = -Jfi - Jso - Jsi,
    dv/dt = Θ(uc - u)(1 - v)/τv- - Θ(u - uc )v/τv+
    dw/dt = Θ(uc - u)(1 - w)/τw- - Θ(u - uc )w/τw+    
    Jfi = -vΘ(u - uc )(1 - u)(u - uc )/τd ,
    Jso = uΘ(uc - u)/τo + Θ(u - uc )/τr ,
    Jsi = -w(1 + tanh[k(u - ucsi)])/2τsi .
τd = 1/5.8    
τr = 130
τsi = 127
τo = 12.5
τv+ = 10
τv- = 18.2
τw+ = 1020    
τw- = 80

uc = 0.13
ucsi = 0.85
k = 10

Below you can explore the model for different parameter values.


Uo Vo Wo Ymax dt it
u, v, w variables are black, blue and red curves. The script makes 1000 it time steps dt.

[1] Flavio Fenton and Alain Karma   Vortex dynamics in three-dimensional continuous myocardium with fiber rotation: Filament instability and fibrillationa   Chaos 8, 20 (1998)


Heart rhythms     updated 7 Dec 2011