Influence of myocardial fiber/sheet orientations on left ventricular mechanical contraction

Eriksson, Thomas; Prassl, Anton J.; Plank, Gernot; Holzapfel, Gerhard

doi:10.1177/1081286513485779

Cited by 101 publications

(78 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The alignment of these myofibers smoothly rotates toward the circumferential direction in the midmyocardial region [4]. The counter-wound helical structure of myofibers serves to equalize the myocyte strain and stress, allows the LV to undergo torsional deformation during myocyte shortening, and thereby optimize the volume of blood ejected during systole (i.e., SV), as demonstrated in previous computational studies [4][5][6][7][8]. The myofiber orientation, therefore, is a key determinant of LV pump function.…”

Section: Introductionmentioning

confidence: 81%

Numerical Evaluation of Myofiber Orientation and Transmural Contractile Strength on Left Ventricular Function

Zhang

Haynes

Campbell

et al. 2015

Journal of Biomechanical Engineering

View full text Add to dashboard Cite

The left ventricle (LV) of the heart is composed of a complex organization of cardiac muscle fibers, which contract to generate force and pump blood into the body. It has been shown that both the orientation and contractile strength of these myofibers vary across the ventricular wall. The hypothesis of the current study is that the transmural distributions of myofiber orientation and contractile strength interdependently impact LV pump function. In order to quantify these interactions a finite element (FE) model of the LV was generated, which incorporated transmural variations. The influences of myofiber orientation and contractile strength on the Starling relationship and the end-systolic (ES) apex twist of the LV were assessed. The results suggest that reductions in contractile strength within a specific transmural layer amplified the effects of altered myofiber orientation in the same layer, causing greater changes in stroke volume (SV). Furthermore, when the epicardial myofibers contracted the strongest, the twist of the LV apex was greatest, regardless of myofiber orientation. These results demonstrate the important role of transmural distribution of myocardial contractile strength and its interplay with myofiber orientation. The coupling between these two physiologic parameters could play a critical role in the progression of heart failure.

show abstract

Section: Introductionmentioning

confidence: 81%

Numerical Evaluation of Myofiber Orientation and Transmural Contractile Strength on Left Ventricular Function

Zhang

Haynes

Campbell

et al. 2015

Journal of Biomechanical Engineering

View full text Add to dashboard Cite

show abstract

“…[11,45,14]) and the orthotropic mechanical activation proposed herein. As computational domain we consider the cube Ω .…”

Section: Test 1: Quasi Compatible Deformationsmentioning

confidence: 98%

“…As an illustrative example, we show how it is possible to derive a simple phenomenological model, similar to the one proposed in [28] and used by several authors [11,9,53] (modulus some modifications). In these models the total active tension, denoted with T a , is described by the equatioṅ…”

Section: Active Stress Formulationmentioning

confidence: 99%

“…Different evolution laws for the active tension could be obtained by assuming that ψ A (F) is a function of the fiber elongation I 4,f . These should follow from the assumptions on the tensorial form of the active stress, as for example in [9,11]. (23)…”

Section: Active Stress Formulationmentioning

confidence: 99%

“…Diastolic preload was chosen (according to the values reported in [11,18]) to range between 4 mmHg and 20 mmHg. In particular we took 5 steps of 4 mmHg as shown in Fig.…”

Section: Test 2: Transmural Slabmentioning

confidence: 99%

See 2 more Smart Citations

Thermodynamically consistent orthotropic activation model capturing ventricular systolic wall thickening in cardiac electromechanics

Rossi

Lassila

Ruiz–Baier

et al. 2014

European Journal of Mechanics - A/Solids

175

View full text Add to dashboard Cite

The complex phenomena underlying mechanical contraction of cardiac cells and their influence in the dynamics of ventricular contraction are extremely important in understanding the overall function of the heart. In this paper we generalize previous contributions on the active strain formulation and propose a new model for the excitation-contraction coupling process. We derive an evolution equation for the active fiber contraction based on configurational forces, which is thermodynamically consistent. Geometrically, we link microscopic and macroscopic deformations giving rise to an orthotropic contraction mechanism that is able to represent physiologically correct thickening of the ventricular wall. A series of numerical tests highlights the importance of considering orthotropic mechanical activation in the heart and illustrates the main features of the proposed model.

show abstract

Effects of Orientations on Efficiency of Energy Harvesting from Heart Motion Using Ultrathin Flexible Piezoelectric Devices

Zhang

et al. 2019

Advcd Theory and Sims

View full text Add to dashboard Cite

Harvesting biomechanical energy from the heart motion with flexible piezoelectric transducers to power implantable devices has attracted much attention in recent years. In vivo animal experiments have shown that the output power of flexible device depends heavily on the patching orientations. In this paper, an electromechanical model with the effects of myocardial fiber is developed to better understand the underlying mechanism of this phenomenon and therefore to choose optimal patching orientations for energy harvesting. Theoretical output voltage of the piezoelectric energy harvester under the heart motion in one cardiac cycle is calculated, and the voltage amplitudes of the harvester with varied patching orientations are compared with the experimental measurements. It is found that the output voltage amplitudes are generally the cosine function of the angle between patching orientation of the piezoelectric energy harvesters (PEHs) and the fiber orientation of the epicardium. The results may serve as a guideline to determine the optimal patching orientation of flexible PEHs mounted on surfaces of fiber structure.

show abstract

Influence of myocardial fiber/sheet orientations on left ventricular mechanical contraction

Cited by 101 publications

References 52 publications

Numerical Evaluation of Myofiber Orientation and Transmural Contractile Strength on Left Ventricular Function

Numerical Evaluation of Myofiber Orientation and Transmural Contractile Strength on Left Ventricular Function

Thermodynamically consistent orthotropic activation model capturing ventricular systolic wall thickening in cardiac electromechanics

Effects of Orientations on Efficiency of Energy Harvesting from Heart Motion Using Ultrathin Flexible Piezoelectric Devices

Contact Info

Product

Resources

About