Component: environment

Component: membrane

$i_stim = {− 80 if (time ≥ 20) ∧ (time ≤ 20.5) 0 if d V d time = − (i_CaL + i_pCa + i_NaCa + i_Cab + i_Na + i_Nab + i_NaK + i_Kto_f + i_Kto_s + i_K1 + i_Ks + i_Kur + i_Kss + i_Kr + i_ClCa + i_stim) / Cm$

Component: calcium_concentration

$d Cai d time = Bi (J_leak + J_xfer − J_up + J_trpn + (i_Cab + i_pCa − 2 i_NaCa) Acap Cm / 2 Vmyo F) d Cass d time = Bss (J_rel VJSR / Vss − J_xfer Vmyo / Vss + i_CaL Acap Cm / 2 Vss F) d CaJSR d time = BJSR (J_tr − J_rel) d CaNSR d time = (J_up − J_leak) Vmyo / VNSR − J_tr VJSR / VNSR Bi = (1 + CMDN_tot Km_CMDN / (Km_CMDN + Cai) 2) − 1 Bss = (1 + CMDN_tot Km_CMDN / (Km_CMDN + Cass) 2) − 1 BJSR = (1 + CSQN_tot Km_CSQN / (Km_CSQN + CaJSR) 2) − 1$

Component: calcium_fluxes

$J_rel = v1 (P_O1 + P_O2) (CaJSR − Cass) P_RyR J_tr = (CaNSR − CaJSR) / tau_tr J_xfer = (Cass − Cai) / tau_xfer J_leak = v2 (CaNSR − Cai) J_up = v3 Cai 2 / (Km_up 2 + Cai 2) J_trpn = k_plus_htrpn Cai (HTRPN_tot − HTRPN_Ca) + k_plus_ltrpn Cai (LTRPN_tot − LTRPN_Ca) − k_minus_htrpn HTRPN_Ca + k_minus_ltrpn LTRPN_Ca d P_RyR d time = − 0.04 P_RyR − 0.1 i_CaL / i_CaL_max e − (V − 5) 2 / 648$

Component: calcium_buffering

$d LTRPN_Ca d time = k_plus_ltrpn Cai (LTRPN_tot − LTRPN_Ca) − k_minus_ltrpn LTRPN_Ca d HTRPN_Ca d time = k_plus_htrpn Cai (HTRPN_tot − HTRPN_Ca) − k_minus_htrpn HTRPN_Ca$

Component: ryanodine_receptors

$d P_O1 d time = k_plus_a Cass n P_C1 + k_minus_b P_O2 + k_minus_c P_C2 − k_minus_a P_O1 + k_plus_b Cass m P_O1 + k_plus_c P_O1 P_C1 = 1 − P_C2 + P_O1 + P_O2 d P_O2 d time = k_plus_b Cass m P_O1 − k_minus_b P_O2 d P_C2 d time = k_plus_c P_O1 − k_minus_c P_C2$

Component: L_type_calcium_current

$i_CaL = g_CaL O (V − E_CaL) d O d time = alpha C4 + Kpcb I1 + 0.001 (alpha I2 − Kpcf O) − 4 beta O + gamma O C1 = 1 − O + C2 + C2 + C3 + C4 + I1 + I2 + I3 d C2 d time = 4 alpha C1 + 2 beta C3 − beta C2 + 3 alpha C2 d C3 d time = 3 alpha C2 + 3 beta C4 − 2 beta C3 + 2 alpha C3 d C4 d time = 2 alpha C3 + 4 beta O + 0.01 (4 Kpcb beta I1 − alpha gamma C4) + 0.002 (4 beta I2 − Kpcf C4) + 4 beta Kpcb I3 − 3 beta C4 + alpha C4 + gamma Kpcf C4 d I1 d time = gamma O + 0.001 (alpha I3 − Kpcf I1) + 0.01 (alpha gamma C4 − 4 beta Kpcf I1) − Kpcb I1 d I2 d time = 0.001 (Kpcf O − alpha I2) + Kpcb I3 + 0.002 (Kpcf C4 − 4 beta I2) − gamma I2 d I3 d time = 0.001 (Kpcf I1 − alpha I3) + gamma I2 + gamma Kpcf C4 − 4 beta Kpcb I3 + Kpcb I3 alpha = 0.4 e (V + 12) / 10 (1 + 0.7 e − (V + 40) 2 / 10 − 0.75 e − (V + 20) 2 / 400) / (1 + 0.12 e (V + 12) / 10) beta = 0.05 e − (V + 12) / 13 gamma = Kpc_max Cass / (Kpc_half + Cass) Kpcf = 13 (1 − e − (V + 14.5) 2 / 100)$

Component: calcium_pump_current

$i_pCa = i_pCa_max Cai 2 / (Km_pCa 2 + Cai 2)$

Component: sodium_calcium_exchange_current

$i_NaCa = k_NaCa × 1 / (K_mNa 3 + Nao 3) × 1 / (K_mCa + Cao) × 1 / (1 + k_sat e (eta − 1) V F / R T) (e eta V F / R T Nai 3 Cao − e (eta − 1) V F / R T Nao 3 Cai)$

Component: calcium_background_current

$i_Cab = g_Cab (V − E_CaN) E_CaN = R T / 2 F ln (Cao / Cai)$

Component: sodium_concentration

$d Nai d time = − (i_Na + i_Nab + 3 i_NaK + 3 i_NaCa) Acap Cm / Vmyo F$

Component: fast_sodium_current

$i_Na = g_Na O_Na (V − E_Na) E_Na = R T / F ln ((0.9 Nao + 0.1 Ko) / (0.9 Nai + 0.1 Ki)) C_Na3 = 1 − O_Na + C_Na1 + C_Na2 + IF_Na + I1_Na + I2_Na + IC_Na2 + IC_Na3 d C_Na2 d time = alpha_Na11 C_Na3 + beta_Na12 C_Na1 + alpha_Na3 IC_Na2 − beta_Na11 C_Na2 + alpha_Na12 C_Na2 + beta_Na3 C_Na2 d C_Na1 d time = alpha_Na12 C_Na2 + beta_Na13 O_Na + alpha_Na3 IF_Na − beta_Na12 C_Na1 + alpha_Na13 C_Na1 + beta_Na3 C_Na1 d O_Na d time = alpha_Na13 C_Na1 + beta_Na2 IF_Na − beta_Na13 O_Na + alpha_Na2 O_Na d IF_Na d time = alpha_Na2 O_Na + beta_Na3 C_Na1 + beta_Na4 I1_Na + alpha_Na12 IC_Na2 − beta_Na2 IF_Na + alpha_Na3 IF_Na + alpha_Na4 IF_Na + beta_Na12 IF_Na d I1_Na d time = alpha_Na4 IF_Na + beta_Na5 I2_Na − beta_Na4 I1_Na + alpha_Na5 I1_Na d I2_Na d time = alpha_Na5 I1_Na − beta_Na5 I2_Na d IC_Na2 d time = alpha_Na11 IC_Na3 + beta_Na12 IF_Na + beta_Na3 IC_Na2 − beta_Na11 IC_Na2 + alpha_Na12 IC_Na2 + alpha_Na3 IC_Na2 d IC_Na3 d time = beta_Na11 IC_Na2 + beta_Na3 C_Na3 − alpha_Na11 IC_Na3 + alpha_Na3 IC_Na3 alpha_Na11 = 3.802 / (0.1027 e − (V + 2.5) / 17 + 0.2 e − (V + 2.5) / 150) alpha_Na12 = 3.802 / (0.1027 e − (V + 2.5) / 15 + 0.23 e − (V + 2.5) / 150) alpha_Na13 = 3.802 / (0.1027 e − (V + 2.5) / 12 + 0.25 e − (V + 2.5) / 150) beta_Na11 = 0.1917 e − (V + 2.5) / 20.3 beta_Na12 = 0.2 e − (V − 2.5) / 20.3 beta_Na13 = 0.22 e − (V − 7.5) / 20.3 alpha_Na3 = 7e-7 e − (V + 7) / 7.7 beta_Na3 = 0.0084 + 0.00002 (V + 7) alpha_Na2 = 1 / (0.188495 e − (V + 7) / 16.6 + 0.393956) beta_Na2 = alpha_Na13 alpha_Na2 alpha_Na3 / beta_Na13 beta_Na3 alpha_Na4 = alpha_Na2 / 1000 beta_Na4 = alpha_Na3 alpha_Na5 = alpha_Na2 / 95000 beta_Na5 = alpha_Na3 / 50$

Component: sodium_background_current

$i_Nab = g_Nab (V − E_Na)$

Component: potassium_concentration

$d Ki d time = − (i_Kto_f + i_Kto_s + i_K1 + i_Ks + i_Kss + i_Kur + i_Kr − 2 i_NaK) Acap Cm / Vmyo F$

Component: fast_transient_outward_potassium_current

$i_Kto_f = g_Kto_f ato_f 3 ito_f (V − E_K) E_K = R T / F ln (Ko / Ki) d ato_f d time = alpha_a (1 − ato_f) − beta_a ato_f d ito_f d time = alpha_i (1 − ito_f) − beta_i ito_f alpha_a = 0.18064 e 0.03577 (V + 30) beta_a = 0.3956 e − 0.06237 (V + 30) alpha_i = 0.000152 e − (V + 13.5) / 7 / (0.0067083 e − (V + 33.5) / 7 + 1) beta_i = 0.00095 e (V + 33.5) / 7 / (0.051335 e (V + 33.5) / 7 + 1)$

Component: slow_transient_outward_potassium_current

$i_Kto_s = g_Kto_s ato_s ito_s (V − E_K) d ato_s d time = (ass − ato_s) / tau_ta_s d ito_s d time = (iss − ito_s) / tau_ti_s ass = 1 / (1 + e − (V + 22.5) / 7.7) iss = 1 / (1 + e (V + 45.2) / 5.7) tau_ta_s = 0.493 e − 0.0629 V + 2.058 tau_ti_s = 270 + 1050 / (1 + e (V + 45.2) / 5.7)$

Component: time_independent_potassium_current

$i_K1 = 0.2938 Ko / (Ko + 210) (V − E_K) / (1 + e 0.0896 (V − E_K))$

Component: slow_delayed_rectifier_potassium_current

$i_Ks = g_Ks nKs 2 (V − E_K) d nKs d time = alpha_n (1 − nKs) − beta_n nKs alpha_n = 0.00000481333 (V + 26.5) (1 − e − 0.128 (V + 26.5)) beta_n = 0.0000953333 e − 0.038 (V + 26.5)$

Component: ultra_rapidly_activating_delayed_rectifier_potassium_current

$i_Kur = g_Kur aur iur (V − E_K) d aur d time = (ass − aur) / tau_aur d iur d time = (iss − iur) / tau_iur tau_aur = 0.493 e − 0.0629 V + 2.058 tau_iur = 1200 − 170 / (1 + e (V + 45.2) / 5.7)$

Component: non_inactivating_steady_state_potassium_current

$i_Kss = g_Kss aKss iKss (V − E_K) d aKss d time = (ass − aKss) / tau_Kss d iKss d time = 0 tau_Kss = 39.3 e − 0.0862 V + 13.17$

Component: rapid_delayed_rectifier_potassium_current

$i_Kr = g_Kr O_K (V − R T / F ln ((0.98 Ko + 0.02 Nao) / (0.98 Ki + 0.02 Nai))) C_K0 = 1 − C_K1 + C_K2 + O_K + I_K d C_K2 d time = kf C_K1 + beta_a1 O_K − kb C_K2 + alpha_a1 C_K2 d C_K1 d time = alpha_a0 C_K0 + kb C_K2 − beta_a0 C_K1 + kf C_K1 d O_K d time = alpha_a1 C_K2 + beta_i I_K − beta_a1 O_K + alpha_i O_K d I_K d time = alpha_i O_K − beta_i I_K alpha_a0 = 0.022348 e 0.01176 V beta_a0 = 0.047002 e − 0.0631 V alpha_a1 = 0.013733 e 0.038198 V beta_a1 = 0.0000689 e − 0.04178 V alpha_i = 0.090821 e 0.023391 (V + 5) beta_i = 0.006497 e − 0.03268 (V + 5)$

Component: sodium_potassium_pump_current

$i_NaK = i_NaK_max f_NaK × 1 / (1 + (Km_Nai / Nai) 1.5) Ko / (Ko + Km_Ko) f_NaK = 1 / (1 + 0.1245 e − 0.1 V F / R T + 0.0365 sigma e − V F / R T) sigma = 1 / 7 (e Nao / 67300 − 1)$

Component: calcium_activated_chloride_current

$i_ClCa = g_ClCa O_ClCa Cai / (Cai + Km_Cl) (V − E_Cl) O_ClCa = 0.2 / (1 + e − (V − 46.7) / 7.8)$