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Simulation Methods and Validation Criteria for Modeling Cardiac Ventricular Electrophysiology.

Krishnamoorthi S, Perotti LE, Borgstrom NP, Ajijola OA, Frid A, Ponnaluri AV, Weiss JN, Qu Z, Klug WS, Ennis DB, Garfinkel A - PLoS ONE (2014)

Bottom Line: We solve the electrophysiology governing equations using the finite element method and compute both a 6-lead precordial electrocardiogram (ECG) and the activation wavefronts over time.We are particularly concerned with the validation of the various methods used in our model and, in this regard, propose a series of validation criteria that we consider essential.Among other components, we conclude that a Purkinje geometry with a high density of Purkinje muscle junctions covering the right and left ventricular endocardial surfaces as well as transmural and apex-to-base gradients in action potential characteristics are necessary to produce ECGs and time activation plots that agree with physiological observations.

View Article: PubMed Central - PubMed

Affiliation: Department of Mechanical and Aerospace Engineering, University of California Los Angeles, Los Angeles, California, United States of America.

ABSTRACT
We describe a sequence of methods to produce a partial differential equation model of the electrical activation of the ventricles. In our framework, we incorporate the anatomy and cardiac microstructure obtained from magnetic resonance imaging and diffusion tensor imaging of a New Zealand White rabbit, the Purkinje structure and the Purkinje-muscle junctions, and an electrophysiologically accurate model of the ventricular myocytes and tissue, which includes transmural and apex-to-base gradients of action potential characteristics. We solve the electrophysiology governing equations using the finite element method and compute both a 6-lead precordial electrocardiogram (ECG) and the activation wavefronts over time. We are particularly concerned with the validation of the various methods used in our model and, in this regard, propose a series of validation criteria that we consider essential. These include producing a physiologically accurate ECG, a correct ventricular activation sequence, and the inducibility of ventricular fibrillation. Among other components, we conclude that a Purkinje geometry with a high density of Purkinje muscle junctions covering the right and left ventricular endocardial surfaces as well as transmural and apex-to-base gradients in action potential characteristics are necessary to produce ECGs and time activation plots that agree with physiological observations.

No MeSH data available.


Related in: MedlinePlus

Tensor field and finite element mesh.(A) Short-axis slice of the linear invariant interpolated tensor field superposed on a coarsened surface mesh. (B) Hexahedral finite element mesh. The stair-stepped nature of the mesh is shown in the zoomed-in view of the model.
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pone-0114494-g001: Tensor field and finite element mesh.(A) Short-axis slice of the linear invariant interpolated tensor field superposed on a coarsened surface mesh. (B) Hexahedral finite element mesh. The stair-stepped nature of the mesh is shown in the zoomed-in view of the model.

Mentions: Only the orientation information, the eigenvectors of the interpolated diffusion tensors, was incorporated into the computational model, not the eigenvalues. This is because the directions of water diffusion correspond with the principal axes of the tissue microstructure, which in turn correspond to the directions of electrical propagation [23]. But there is no reason to expect that the magnitudes of electrical current diffusion are related to the magnitudes of water diffusion. For the electrical current diffusion magnitudes, we used eigenvalues in the ratio 4∶2∶1 [24], with the magnitudes scaled to reflect correct conduction velocities (see below). The interpolated tensor produced a value for the principal fiber direction at each integration point (Fig. 1A).


Simulation Methods and Validation Criteria for Modeling Cardiac Ventricular Electrophysiology.

Krishnamoorthi S, Perotti LE, Borgstrom NP, Ajijola OA, Frid A, Ponnaluri AV, Weiss JN, Qu Z, Klug WS, Ennis DB, Garfinkel A - PLoS ONE (2014)

Tensor field and finite element mesh.(A) Short-axis slice of the linear invariant interpolated tensor field superposed on a coarsened surface mesh. (B) Hexahedral finite element mesh. The stair-stepped nature of the mesh is shown in the zoomed-in view of the model.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4262432&req=5

pone-0114494-g001: Tensor field and finite element mesh.(A) Short-axis slice of the linear invariant interpolated tensor field superposed on a coarsened surface mesh. (B) Hexahedral finite element mesh. The stair-stepped nature of the mesh is shown in the zoomed-in view of the model.
Mentions: Only the orientation information, the eigenvectors of the interpolated diffusion tensors, was incorporated into the computational model, not the eigenvalues. This is because the directions of water diffusion correspond with the principal axes of the tissue microstructure, which in turn correspond to the directions of electrical propagation [23]. But there is no reason to expect that the magnitudes of electrical current diffusion are related to the magnitudes of water diffusion. For the electrical current diffusion magnitudes, we used eigenvalues in the ratio 4∶2∶1 [24], with the magnitudes scaled to reflect correct conduction velocities (see below). The interpolated tensor produced a value for the principal fiber direction at each integration point (Fig. 1A).

Bottom Line: We solve the electrophysiology governing equations using the finite element method and compute both a 6-lead precordial electrocardiogram (ECG) and the activation wavefronts over time.We are particularly concerned with the validation of the various methods used in our model and, in this regard, propose a series of validation criteria that we consider essential.Among other components, we conclude that a Purkinje geometry with a high density of Purkinje muscle junctions covering the right and left ventricular endocardial surfaces as well as transmural and apex-to-base gradients in action potential characteristics are necessary to produce ECGs and time activation plots that agree with physiological observations.

View Article: PubMed Central - PubMed

Affiliation: Department of Mechanical and Aerospace Engineering, University of California Los Angeles, Los Angeles, California, United States of America.

ABSTRACT
We describe a sequence of methods to produce a partial differential equation model of the electrical activation of the ventricles. In our framework, we incorporate the anatomy and cardiac microstructure obtained from magnetic resonance imaging and diffusion tensor imaging of a New Zealand White rabbit, the Purkinje structure and the Purkinje-muscle junctions, and an electrophysiologically accurate model of the ventricular myocytes and tissue, which includes transmural and apex-to-base gradients of action potential characteristics. We solve the electrophysiology governing equations using the finite element method and compute both a 6-lead precordial electrocardiogram (ECG) and the activation wavefronts over time. We are particularly concerned with the validation of the various methods used in our model and, in this regard, propose a series of validation criteria that we consider essential. These include producing a physiologically accurate ECG, a correct ventricular activation sequence, and the inducibility of ventricular fibrillation. Among other components, we conclude that a Purkinje geometry with a high density of Purkinje muscle junctions covering the right and left ventricular endocardial surfaces as well as transmural and apex-to-base gradients in action potential characteristics are necessary to produce ECGs and time activation plots that agree with physiological observations.

No MeSH data available.


Related in: MedlinePlus