MODEL0911989198
type: SBMLModel
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units def: 626227
parameter: 127672
parameter: 127657
rule: 127611
parameter: 127681
parameter: 127666
parameter: 127713
parameter: 127654
parameter: 127663
parameter: 127707
compartment: 127604
parameter: 127639
parameter: 127651
parameter: 127723
parameter: 127648
parameter: 127660
volume units: volume
parameter: 127695
notes: This a model from the article: Vortex dynamics in three-dimensional continuous myocardium with fiber rotation: Filament instability and fibrillation. Fenton F, Karma A. Chaos 1998 Mar;8(1):20-47 12779708 , Abstract: Wave propagation in ventricular muscle is rendered highly anisotropic by the intramural rotation of the fiber. This rotational anisotropy is especially important because it can produce a twist of electrical vortices, which measures the rate of rotation (in degree/mm) of activation wavefronts in successive planes perpendicular to a line of phase singularity, or filament. This twist can then significantly alter the dynamics of the filament. This paper explores this dynamics via numerical simulation. After a review of the literature, we present modeling tools that include: (i) a simplified ionic model with three membrane currents that approximates well the restitution properties and spiral wave behavior of more complex ionic models of cardiac action potential (Beeler-Reuter and others), and (ii) a semi-implicit algorithm for the fast solution of monodomain cable equations with rotational anisotropy. We then discuss selected results of a simulation study of vortex dynamics in a parallelepipedal slab of ventricular muscle of varying wall thickness (S) and fiber rotation rate (theta(z)). The main finding is that rotational anisotropy generates a sufficiently large twist to destabilize a single transmural filament and cause a transition to a wave turbulent state characterized by a high density of chaotically moving filaments. This instability is manifested by the propagation of localized disturbances along the filament and has no previously known analog in isotropic excitable media. These disturbances correspond to highly twisted and distorted regions of filament, or "twistons," that create vortex rings when colliding with the natural boundaries of the ventricle. Moreover, when sufficiently twisted, these rings expand and create additional filaments by further …
curated: false
parameter: 127645
parameter: 127689
parameter: 127701
parameter: 127642
parameter: 127677
rule: 127629
rule: 127617
parameter: 127727
rule: 127635
parameter: 127711
rule: 127632
rule: 127620
parameter: 127683
parameter: 127715
area units: area
length unit: 027038
units def: 626396
parameter: 127709
units def: 626505
parameter: 127697
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units def: 626469
parameter: 127703
units def: 626251
substance units: 608838
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parameter: 127679
parameter: 127691
rule: 127606
parameter: 127729
time units: 626505
parameter: 127685
parameter: 127717
is described by: http://identifiers.org/pubmed/12779708
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rule: 127626
parameter: 127699
parameter: 127705
parameter: 127721
parameter: 127693
units def: 626432
parameter: 127687
parameter: 127719
units def: 626299
parameter: 127675
rule: 127608
parameter: 127669
name: Fenton1998_MyocardiumVortexDynamics

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name: p

626227
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127672
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name: p

127657
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127681
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name: J_fi

626251
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name: V_0

626275
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name: tau_si

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127663
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name: IstimPeriod

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name: tau_w_plus

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name: IstimAmplitude

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name: tau_v_plus

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name: IstimEnd

127689
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127701
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127642
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name: IstimStart

127677
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127711
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name: J_si

127683
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value: NaN
name: tau_d

127715
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units: dimensionless
value: 0.85
name: u_csi

127709
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value: 130.0
name: tau_r

626505
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127697
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626359
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127703
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127685
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name: g_fi_max

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127721
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127669
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