Environmental Engineering Reference
In-Depth Information
4.1 Electro-Mechanical Coupling in a Bi-Ventricular
Geometry
The CCM tool is used to simulate a pumping heart, focusing on the electro-
mechanical propagation through the tissue. It has been reported that the specific loca-
tion where the stimuli enters the myocardium, along with the anatomical variations,
determine the overall activation sequence of the heart and the epicardial breakthrough
of the electrical wave (Durrer et al.
1970
). Obtaining an accurate representation of the
Purkinje system in the in-vivo heart is a huge challenge still unsolved, and the vari-
ability of the Purkinje fiber geometry across and within species is unknown. We aim
to understand the effect of modelling various initial stimuli protocols and its result-
ing electromechanical response. A Purkinje system modeller has been developed by
Sebastian et al. (
2012
) at the University of Valencia. Each initial stimuli protocol is
composed of a set of locations and times determined by the Purkinje tree structure and
its PMJs, where the electrical stimuli reach the right or left ventricular myocardium.
In Arís et al. (
2014
), a bi-ventricular geometry is employed to study the model's
sensitivity to different settings of the heart structure. Fourteen initial activation pro-
tocols (Pk1, Pk2,…, Pk14) and two transmural fiber field interpolation models (ST1
and ST3) are tested. For each case the simulations are evaluated and analyzed to
assess whether the variation of the inputs has an impact on the pumping motion of
the muscle. Two different fiber fields are assessed, both coming from a rule-based
synthetic fiber distribution: linear and cubic Streeter models (ST1 and ST3). When
possible, a third one coming from experimental measurements (from Diffusion Ten-
Fig. 5
Rabbit ventricular
mesh containing 432,000
tetrahedra as generated from
magnetic resonance images
at the Oxford University. The
figure shows the surface
meshes
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