Table 1.
Overview of studies utilizing the kinematic growth theory to study G&R in the heart. Note that studies on organogenesis, e.g., [52,176] are not included. Fg is the inelastic growth deformation gradient; Me is the elastic Mandel stress [177] ; λ denote fiber stretch, ϑ denote growth multipliers; f0, s0, and n0 denote myocyte, sheet, and sheet-normal directions and E• are strains in the respective direction; subscripts •crit denote physiologial limit levels, subscripts •hom denote homeostatic levels of the specific parameter; subscripts •e denote values with respect to the elastic deformation gradient Fe; k(•) are growth scaling functions.
Model | Geometry and Material | Driving Factor | Growth Laws |
---|---|---|---|
Kroon et al. [38] | Truncated ellipsoid; transversely isotropic [178] | Deviation of myofiber strain from its homeostatic level shom = 0.13 | where β is a rate constant |
Göktepe et al. [39] | Regularly shaped bi-ventricular model; isotropic material | Deviation from strain for eccentric growth Deviation from Mandel stress for concentric growth | Eccentric growth: Fg = I + [ϑ∥ − 1] f0 ⊗ f0 Concentric growth: Fg = I + [ϑ⊥ − 1] s0 ⊗ s0 |
Rausch et al. [44] | Regularly shaped bi-ventricular model; orthotropic Holzapfel–Ogden [106] | with τ the Kirchhoff stress tensor and pcrit the baseline pressure level | Fg = I + [ϑ − 1] s0 ⊗ s0 |
Klepach et al. [46] | Patient-specific LV; transversely isotropic Guccione [102] | Same as Rausch et al. [44] | |
Kerckhoffs et al. [47] | Thick-walled truncated ellipsoid; transversely isotropic Guccione [102] | Stimulus for axial fiber growth sl = max (Ef) − Ef,set, and radial fiber growth st = min (Ecross,max) − Ecross,set as differences between fiber strain Ef and maximum principal strain Ecross,max of the cross-sectional strain tensor: Ecross = [Es Esn; Esn En] and set-points •set | Transversely isotropic, incremental growth tensor, described by sigmoids and dependent on 10 parameters |
Lee et al. [43] | Patient-specific LV; transversely isotropic Guccione [102] | Fg = (ϑ − 1)f0 ⊗ f0 + I | |
Genet et al. [48] | Four-chamber human heart model; orthotropic Guccione [102] | where τ is a scaling parameter in time and 〈〉 Macaulay brackets | Eccentric growth: Fg = I + [ϑ − 1] f0 ⊗ f0 Concentric growth: Fg = ϑI + [1 − ϑ] f0 ⊗ f0 |
Witzenburg and Holmes [49] | LV treated as thin-walled spherical pressure vessel; time-varying elastance compartmental model | Same as Kerckhoffs et al. [47] | Same as Kerckhoffs et al. [47] |
Del Bianco et al. [50] | Truncated ellipsoid; orthotropic Holzapfel–Ogden [106] | Local growth increments ϑn between cycles n and n + 1: | Same as Göktepe et al. [39] for eccentric growth |
Peirlinck et al. [51] | Subject specific LV; orthotropic Holzapfel–Ogden [106] | where τ is a scaling parameter and 〈〉 Macaulay brackets | Fg = ϑ∥ [f0 ⊗ f0] + ϑ⊥ [I − f0 ⊗ f0] |