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Component: environment

Component: membrane

\frac{d}{d time} (V) = \frac{Istim - (i_Na + i_s + i_x1 + i_K1)}{C}

IStimC = Istim

Component: fast_sodium_current

i_Na = g_Na m^{3.0} h (V - E_Na)

Component: fast_sodium_current_m_gate

alpha_m = \frac{0.32 (47.13 + V)}{1.0 - (ⅇ^{- V - 47.13})}

beta_m = 0.08 ⅇ^{\frac{- V}{11.0}}

\frac{d}{d time} (m) = alpha_m (1.0 - m) - (beta_m m)

Component: fast_sodium_current_h_gate

alpha_h = \{\begin{matrix} 0.135 ⅇ^{\frac{-80.0 - V}{6.8}} if V < -40.0 \\ 0.0 otherwise \end{matrix}

beta_h = \{\begin{matrix} 3.56 ⅇ^{0.079 V} + 3.1e5 ⅇ^{0.35 V} if V < -40.0 \\ \frac{1.0}{0.13 (1.0 + ⅇ^{\frac{- (V + 10.66)}{11.1}})} otherwise \end{matrix}

\frac{d}{d time} (h) = alpha_h (1.0 - h) - (beta_h h)

Component: slow_inward_current

E_s = -82.3 - (13.0287 \ln (Cai 0.001)) i_s = g_s d f (V - E_s) \frac{d}{d time} (Cai) = (-0.01) i_s + 0.07 (0.0001 - Cai)

Component: slow_inward_current_d_gate

alpha_d = \frac{0.095 ⅇ^{- (\frac{V - 5.0}{100.0})}}{1.0 + ⅇ^{- (\frac{V - 5.0}{13.89})}} beta_d = \frac{0.07 ⅇ^{- (\frac{V + 44.0}{59.0})}}{1.0 + ⅇ^{\frac{V + 44.0}{20.0}}} \frac{d}{d time} (d) = alpha_d (1.0 - d) - (beta_d d)

Component: slow_inward_current_f_gate

alpha_f = \frac{0.012 ⅇ^{- (\frac{V + 28.0}{125.0})}}{1.0 + ⅇ^{\frac{V + 28.0}{6.67}}} beta_f = \frac{0.0065 ⅇ^{- (\frac{V + 30.0}{50.0})}}{1.0 + ⅇ^{- (\frac{V + 30.0}{5.0})}} \frac{d}{d time} (f) = alpha_f (1.0 - f) - (beta_f f)

Component: time_dependent_outward_current

i_x1 = x1 (8.0e-3) \frac{ⅇ^{0.04 (V + 77.0)} - 1.0}{ⅇ^{0.04 (V + 35.0)}}

Component: time_dependent_outward_current_x1_gate

alpha_x1 = 0.0005 \frac{ⅇ^{\frac{V + 50.0}{12.1}}}{1.0 + ⅇ^{\frac{V + 50.0}{17.5}}} beta_x1 = 0.0013 \frac{ⅇ^{- (\frac{V + 20.0}{16.67})}}{1.0 + ⅇ^{- (\frac{V + 20.0}{25.0})}} \frac{d}{d time} (x1) = alpha_x1 (1.0 - x1) - (beta_x1 x1)

Component: time_independent_outward_current

i_K1 = 0.0035 (4.0 \frac{ⅇ^{0.04 (V + 85.0)} - 1.0}{ⅇ^{0.08 (V + 53)} + ⅇ^{0.04 (V + 53.0)}} + 0.2 \frac{V + 23.0}{1.0 - (ⅇ^{(-0.04) (V + 23.0)})})

Source: Derived from workspace Ebihara, Johnson, 1980 at changeset 276e14b37407.

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Fast sodium current in cardiac muscle: A quantitative description