A multiscale model for eccentric and concentric cardiac growth through sarcomerogenesis

2010-08-07
Göktepe, Serdar
Parker, Kit
Kuhl, Ellen
We present a novel computational model for maladaptive cardiac growth in which kinematic changes of the cardiac chambers are attributed to alterations in cytoskeletal architecture and in cellular morphology. We adopt the concept of finite volume growth characterized through the multiplicative decomposition of the deformation gradient into an elastic part and a growth part. The functional form of its growth tensor is correlated to sarcomerogenesis, the creation and deposition of new sarcomere units. In response to chronic volume-overload, an increased diastolic wall strain leads to the addition of sarcomeres in series, resulting in a relative increase in cardiomyocyte length, associated with eccentric hypertrophy and ventricular dilation. In response to chronic pressure-overload, an increased systolic wall stress leads to the addition of sacromeres in parallel, resulting in a relative increase in myocyte cross sectional area, associated with concentric hypertrophy and ventricular wall thickening. The continuum equations for both forms of maladaptive growth are discretized in space using a nonlinear finite element approach, and discretized in time using the implicit Euler backward scheme. We explore a generic bi-ventricular heart model in response to volume- and pressure-overload to demonstrate how local changes in cellular morphology translate into global alterations in cardiac form and function.
JOURNAL OF THEORETICAL BIOLOGY

Suggestions

A PHASE FIELD APPROACH TO MODEL FRACTURE OF ARTERIAL WALLS
GÜLTEKİN, Osman; Dal, Hüsnü; HOLZAPFEL, Gerhard A (2016-06-10)
This study uses a recently developed phase-field approach to model fracture of arterial walls with an emphasis on aortic tissues. We start by deriving the regularized crack surface to overcome complexities inherent in sharp crack discontinuities, thereby relaxing the acute crack surface topology into a diffusive one. In fact, the regularized crack surface possesses the property of Gamma-Convergence, i.e. the sharp crack topology is restored with a vanishing length-scale parameter. Next, we deal with the con...
A Parametric Estimation Approach to Instantaneous Spectral Imaging
Öktem, Sevinç Figen; Davila, Joseph M (2014-12-01)
Spectral imaging, the simultaneous imaging and spectroscopy of a radiating scene, is a fundamental diagnostic technique in the physical sciences with widespread application. Due to the intrinsic limitation of two-dimensional (2D) detectors in capturing inherently three-dimensional (3D) data, spectral imaging techniques conventionally rely on a spatial or spectral scanning process, which renders them unsuitable for dynamic scenes. In this paper, we present a nonscanning (instantaneous) spectral imaging techn...
A normalized set of force and permeance data for doubly-salient magnetic geometries
Mahariq, İbrahim; Ertan, Hulusi Bülent; Department of Electrical and Electronics Engineering (2009)
In this study, a model is developed to represent doubly-salient magnetic circuits and to fit finite element analysis for the aim of obtaining a set of normalized normal force, tangential force, and permeance variation data. To obtain the desired data FE field solution method is used. The reliability of finite element results have been verified by three steps; first, comparing the numerical results with analytically calculated permeance, second, by solving two switch reluctance motors and comparing the resul...
A Crack Phase-field Model to Analyze Aortic Dissections
Holzapfel, Gerhard A.; Gültekin, Osman; Hager, Sandra P.; Dal, Hüsnü (2019-09-05)
This study analyzes the lethal clinical condition of aortic dissections from a numerical point of view.On the basis of our previous contributions [1,2], we apply a holistic geometrical approach to fracture,namely the crack phase-field, which inherits the intrinsic features of gradient damage and variationalfracture mechanics. The continuum framework captures anisotropy, is thermodynamically consistentand based on finite strains. The balance of linear momentum and the crack evolution equation governthe coupl...
A new 3D FEM formulation for the solution of potential fields in magnetic induction problems
Tek, Mustafa; Gençer, Nevzat Güneri (1997-11-02)
Time-varying magnetic fields are applied to living tissues for different purposes in medicine. For all applications, the induced current distributions must be accurately estimated in order to obtain the desired medical results. In this study a new 3D finite element method (FEM) formulation is derived. A code is prepared to implement these formulations using 20 noded isoparametric cubic elements. The accuracy of solutions is tested for three simple geometries and series expansion method is used to derive ana...
Citation Formats
S. Göktepe, K. Parker, and E. Kuhl, “A multiscale model for eccentric and concentric cardiac growth through sarcomerogenesis,” JOURNAL OF THEORETICAL BIOLOGY, pp. 433–442, 2010, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/57545.