Optimal velocity and safety of discontinuous conduction through the heterogeneous Purkinje-ventricular junction
Catherine
Lloyd
Auckland Bioengineering Institute, The University of Auckland
Model Status
This CellML model runs in both COR and PCEnv to reproduce the published results. The CellML model has been based on both the published paper and the original C Code the model was written in. Our thanks go to the authors Oleg and Philip for their help in curating the CellML model and getting it to reproduce their original results.
Model Structure
ABSTRACT: Slow and discontinuous wave conduction through non-uniform junctions in cardiac tissues is generally considered unsafe and pro-arrythmogenic. However, the relationships between tissue structure, wave conduction velocity and safety at such junctions are unknown. We develop a structurally and electrophysiologically detailed model of the canine Purkinje-ventricular junction (PVJ) and vary its heterogeneity parameters in order to determine such relationships. We show that neither very fast nor very slow conduction is safe, and there exists an optimal velocity providing the maximum safety factor of conduction through the junction. The resultant conduction time delay across the PVJ is a natural consequence of the electrophysiological and morphological differences between the Purkinje fibre and ventricular tissue. The delay allows the PVJ to accumulate and pass sufficient charge to excite the adjacent ventricular tissue, but is not long enough for the source-to-load mismatch at the junction to be enhanced over time. The observed relationships between the conduction velocity and safety factor can provide new insights into optimal conditions for wave propagation through non-uniform junctions between various cardiac tissues.
model diagram
Schematic diagram of the cell model.
The original paper reference is cited below:
Optimal velocity and safety of discontinuous conduction through the heterogeneous Purkinje-ventricular junction, Oleg V. Aslanidi, Philip Stewart, Mark R. Boyett and Henggui Zhang, 2009, Biophysical Journal, volume 97, 20-39. PubMed ID: 19580741
i_Na
fast sodium current
i_Na_L
late sodium current
i_Ca_L
L-type calcium current
i_Ca_T
T-type calcium current
i_to_1
transient outward potassium current
i_Kr
fast delayed rectifier potassium current
i_Ks
slow delayed rectifier potassium current
i_K1
inward rectifier potassium current
i_K_p
plateau potassium current
i_to_2
calcium-dependent transient outward chloride current
i_NaCa
sodium-calcium exchanger current
i_NaK
sodium-potassium pump current
i_Ca_p
calcium pump current
CT_K_Cl
potassium-chloride cotransporter
CT_Na_Cl
sodium-chloride cotransporter
background_currents
background currents
intracellular_ion_concentrations
intracellular ion concentrations
Ca_i
intracellular calcium concentration
Ca_MK_act
calcium-calmodulin-dependent protein kinase
Ca_NSR
calcium concentration in the non-juctional sarcoplasmic reticulum
Ca_JSR
calcium concentration in the juctional sarcoplasmic reticulum
Ca_r
restricted space calcium concentration
q_rel
sarcoplasmic reticulum calcium release flux
q_leak
sarcoplasmic reticulum calcium leak flux
q_up
sarcoplasmic reticulum calcium uptake flux
q_tr
sarcoplasmic reticulum calcium transfer flux
Optimal velocity and safety of discontinuous conduction through the heterogeneous Purkinje-ventricular junction
3997202009-10-082009-07-08PStewartCatherine Lloyd19580741
This is the CellML description of Aslanidi et al.'s mathematical model of of the caninine Purkinje-ventricular junction
MRBoyettHZhangkeywordc.lloyd@auckland.ac.nz
The Aslanidi et al. 2009 model of the caninine Purkinje-ventricular junction
CaninePurkinje fibreventricular myocyteAuckland Bioengineering InstituteThe University of AucklandelectrophysiologycardiacOVAslanidiBiophysical Journal0.11000100000CatherineMayLloyd