Garny, Kohl, Hunter, Boyett, Noble, 2003

Model Status

This version of the CellML model was created by Alan Garny of Oxford University, it has been unit checked and the model runs in both COR and PCEnv to reproduce the published results

ValidateCellML confirms this model as valid CellML with full unit consistency.

Model Structure

Cardiac multicellular modeling has traditionally focused on ventricular electromechanics. More recently, models of the atria have started to emerge, and there is much interest in addressing sinoatrial node (SAN) structure and function. The SAN has a heterogeneous structure, with smaller cells being located more centrally and larger ones toward the periphery. In addition, the central SAN cells have a lower maximum diastolic potential (MDP), upstroke velocity (UV), and intrinsic pacemaking rate than the peripheral cells. In the current model, Garny et al. (2003) build further on the SAN model published by Zhang et al. (2000) (also described in CellML) and add a third category of cell called transitional cells. These transitional cell types are obtained by gradation between central and peripheral cell models, using a scaling parameter implemented in the model as a function of cell location relative to the SAN centre. The variable is called dCell and it specifies the relative distance of the cell relative to the centre of the SAN: if dCell=1 it is a peripheral cell model, if dCell=0 it is a central cell, and if dCell has a value between 0 and 1 the model describes a transitional cell.

There is a second variable which varies between models; version. If version=0 the CellML model behaves like the Zhang et al. 2000 model. If version=1 the CellML model describes a 0D capable, or suitable for single cell modelling, and if version=2 the CellML model describes a 1D capable, or suitable for multicellular modelling. By default the CellML model is setup to describe a central SAN cell (dCell=0) suitable for single cell modelling (version=1).

The complete original paper reference is cited below.

One-dimensional rabbit sinoatrial node models: benefits and limitations, A. Garny, P. Kohl, P.J. Hunter, M.R. Boyett and D. Noble, 2003, The Journal of Cardiovascular Electrophysiology , 14, S121-S132. PubMed ID: 14760914

A schematic diagram describing the current flows across the cell membrane that are captured in the Garny et al 2003 'published' and "0D capable' models of the action potentials in the cells of the SA node. The 1D capable model has one additional current called I_Cap - or a persistant calcium current.