Development of an in vivo method for determining material properties of passive myocardium

Remme, Espen W.; Hunter, Peter; Smiseth, Otto A.; Stevens, Carey; Rabben, Stein Inge; Skulstad, Helge; Angelsen, Bjørn

doi:10.1016/j.jbiomech.2003.09.023

Cited by 24 publications

(19 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Some studies with more realistic FE models however only used 2 strain measurements to fit for the optimum material parameters [34-34], while others that used 500 to 700 strain measurements for optimization required a significant amount of computing time and power [4, 36]. There have also been labor intensive, trial-and-error approaches towards optimization [4, 34] as well as automated optimization algorithms.…”

Section: Discussionmentioning

confidence: 99%

A Computationally Efficient Formal Optimization of Regional Myocardial Contractility in a Sheep With Left Ventricular Aneurysm

Sun

Stander

Jhun

et al. 2009

Journal of Biomechanical Engineering

129

View full text Add to dashboard Cite

A non-invasive method for estimating regional myocardial contractility in vivo would be of great value in the design and evaluation of new surgical and medical strategies to treat and/or prevent infarction-induced heart failure. As a first step towards developing such a method, an explicit finite element (FE) model-based formal optimization of regional myocardial contractility in a sheep with left ventricular (LV) aneurysm was performed using tagged magnetic resonance (MR) images and cardiac catheterization pressures. From the tagged MR images, 3-dimensional (3D) myocardial strains, LV volumes and geometry for the animal-specific 3D FE model of the LV were calculated, while the LV pressures provided physiological loading conditions. Active material parameters (T max_B and T max_R ) in the non-infarcted myocardium adjacent to the aneurysm (borderzone) and in myocardium remote from the aneurysm were estimated by minimizing the errors between FE model-predicted and measured systolic strains and LV volumes using the successive response surface method for optimization. The significant depression in optimized T max_B relative to T max_R was confirmed by direct ex vivo force measurements from skinned fiber preparations. The optimized values of T max_B and T max_R were not overly sensitive to the passive material parameters specified. The computation time of less than 5 hours associated with our proposed method for estimating regional myocardial contractility in vivo makes it a potentially very useful clinical tool.

show abstract

Section: Discussionmentioning

confidence: 99%

A Computationally Efficient Formal Optimization of Regional Myocardial Contractility in a Sheep With Left Ventricular Aneurysm

Sun

Stander

Jhun

et al. 2009

Journal of Biomechanical Engineering

129

View full text Add to dashboard Cite

show abstract

“…36 The three-dimensional geometry of right and left ventricles in dog and pig hearts and the myocyte arrangement throughout the ventricular wall in these species has been well characterized. [37][38][39] These data have been incorporated into a detailed finite element model of cardiac anatomy, together with information about myocardial material properties. 40,41 Cellular mechanisms, including membrane channel characteristics, excitation-contraction coupling and cross-bridge cycling dynamics, are also included in this continuum description.…”

Section: Distribution Of Stress In the Myocardiummentioning

confidence: 99%

Gene Expression of Stretch‐activated Channels and Mechanoelectric Feedback in the Heart

Kelly

Mackenzie

Hunter

et al. 2006

Clin Exp Pharma Physio

View full text Add to dashboard Cite

1. Mechanoelectric feedback (MEF) in the heart is the process by which mechanical forces on the myocardium can change its electrical properties. Mechanoelectric feedback has been demonstrated in many animal models, ranging from isolated cells, through isolated hearts to whole animals. In humans, MEF has been demonstrated directly in both the atria and the ventricles. It seems likely that MEF provides either the trigger or the substrate for some types of clinically important arrhythmias. 2. Mechanoelectric feedback may arise because of the presence of stretch-sensitive (or mechano-sensitive) ion channels in the cell membrane of the cardiac myocytes. Two types have been demonstrated: (i) a non-specific cation channel (stretch-activated channel (SAC); conductance of approximately 25 pS); and (ii) a potassium channel with a conductance of approximately 100 pS. The gene coding for the SAC has not yet been identified. The gene for the potassium channel is likely to be TREK, a member of the tandem pore potassium channel gene family. We have recorded stretch-sensitive potassium channels in rat isolated myocytes that have the properties of TREK channels expressed in heterologous systems. 3. It has been shown that TREK mRNA is expressed heterogeneously in the rat ventricular wall, with 17-fold more expression in endocardial compared with epicardial cells. This difference is reflected in the TREK currents recorded from endocardial and epicardial cells using whole-cell patch-clamp techniques, although the difference in current density was less pronounced (approximately threefold). Consistent with this, we show here that when the ventricle is stretched by inflation of an intraventricular balloon in a Langendorff perfused rat isolated heart, action potential shortening was more pronounced in the endocardium (30% shortening at 40 mmHg) compared with that in the epicardium (10% shortening at the same pressure). 4. Computer models of the mechanics of the (pig) heart show pronounced spatial variations in strain in the myocardium with large transmural differences (in the left ventricle in particular) and also large differences between the base and apex of the ventricle. 5. The importance of MEF and the non-homogeneous gene expression and strain distribution for arrhythmias is discussed.

show abstract

“…2015; Remme et al. 2004), which results in multiple parameter combinations corresponding to equivalent solutions in the optimization process. The existence of multiple solutions for the inverse problem limits the interpretation of these parameters for characterizing patient pathology and understanding changes in material properties under conditions of HF.…”

Section: Introductionmentioning

confidence: 99%

Improved identifiability of myocardial material parameters by an energy-based cost function

Nasopoulou

Shetty

Lee

et al. 2017

Biomech Model Mechanobiol

View full text Add to dashboard Cite

Myocardial stiffness is a valuable clinical biomarker for the monitoring and stratification of heart failure (HF). Cardiac finite element models provide a biomechanical framework for the assessment of stiffness through the determination of the myocardial constitutive model parameters. The reported parameter intercorrelations in popular constitutive relations, however, obstruct the unique estimation of material parameters and limit the reliable translation of this stiffness metric to clinical practice. Focusing on the role of the cost function (CF) in parameter identifiability, we investigate the performance of a set of geometric indices (based on displacements, strains, cavity volume, wall thickness and apicobasal dimension of the ventricle) and a novel CF derived from energy conservation. Our results, with a commonly used transversely isotropic material model (proposed by Guccione et al.), demonstrate that a single geometry-based CF is unable to uniquely constrain the parameter space. The energy-based CF, conversely, isolates one of the parameters and in conjunction with one of the geometric metrics provides a unique estimation of the parameter set. This gives rise to a new methodology for estimating myocardial material parameters based on the combination of deformation and energetics analysis. The accuracy of the pipeline is demonstrated in silico, and its robustness in vivo, in a total of 8 clinical data sets (7 HF and one control). The mean identified parameters of the Guccione material law were and (, , ) for the HF cases and and (, , ) for the healthy case.

show abstract

Development of an in vivo method for determining material properties of passive myocardium

Cited by 24 publications

References 17 publications

A Computationally Efficient Formal Optimization of Regional Myocardial Contractility in a Sheep With Left Ventricular Aneurysm

A Computationally Efficient Formal Optimization of Regional Myocardial Contractility in a Sheep With Left Ventricular Aneurysm

Gene Expression of Stretch‐activated Channels and Mechanoelectric Feedback in the Heart

Improved identifiability of myocardial material parameters by an energy-based cost function

Contact Info

Product

Resources

About