TY - JOUR
T1 - Computational Investigation of Transmural Differences in Left Ventricular Contractility
AU - Wang, Hua
AU - Zhang, Xiaoyan
AU - Dorsey, Shauna M.
AU - McGarvey, Jeremy R.
AU - Campbell, Kenneth S.
AU - Burdick, Jason A.
AU - Gorman, Joseph H.
AU - Pilla, James J.
AU - Gorman, Robert C.
AU - Wenk, Jonathan F.
N1 - Publisher Copyright:
© Copyright 2016 by ASME.
PY - 2016/11/1
Y1 - 2016/11/1
N2 - Myocardial contractility of the left ventricle (LV) plays an essential role in maintaining normal pump function. A recent ex vivo experimental study showed that cardiomyocyte force generation varies across the three myocardial layers of the LV wall. However, the in vivo distribution of myocardial contractile force is still unclear. The current study was designed to investigate the in vivo transmural distribution of myocardial contractility using a noninvasive computational approach. For this purpose, four cases with different transmural distributions of maximum isometric tension (Tmax) and/or reference sarcomere length (lR) were tested with animal-specific finite element (FE) models, in combination with magnetic resonance imaging (MRI), pressure catheterization, and numerical optimization. Results of the current study showed that the best fit with in vivo MRI-derived deformation was obtained when Tmax assumed different values in the subendocardium, midmyocardium, and subepicardium with transmurally varying lR. These results are consistent with recent ex vivo experimental studies, which showed that the midmyocardium produces more contractile force than the other transmural layers. The systolic strain calculated from the best-fit FE model was in good agreement with MRI data. Therefore, the proposed noninvasive approach has the capability to predict the transmural distribution of myocardial contractility. Moreover, FE models with a nonuniform distribution of myocardial contractility could provide a better representation of LV function and be used to investigate the effects of transmural changes due to heart disease.
AB - Myocardial contractility of the left ventricle (LV) plays an essential role in maintaining normal pump function. A recent ex vivo experimental study showed that cardiomyocyte force generation varies across the three myocardial layers of the LV wall. However, the in vivo distribution of myocardial contractile force is still unclear. The current study was designed to investigate the in vivo transmural distribution of myocardial contractility using a noninvasive computational approach. For this purpose, four cases with different transmural distributions of maximum isometric tension (Tmax) and/or reference sarcomere length (lR) were tested with animal-specific finite element (FE) models, in combination with magnetic resonance imaging (MRI), pressure catheterization, and numerical optimization. Results of the current study showed that the best fit with in vivo MRI-derived deformation was obtained when Tmax assumed different values in the subendocardium, midmyocardium, and subepicardium with transmurally varying lR. These results are consistent with recent ex vivo experimental studies, which showed that the midmyocardium produces more contractile force than the other transmural layers. The systolic strain calculated from the best-fit FE model was in good agreement with MRI data. Therefore, the proposed noninvasive approach has the capability to predict the transmural distribution of myocardial contractility. Moreover, FE models with a nonuniform distribution of myocardial contractility could provide a better representation of LV function and be used to investigate the effects of transmural changes due to heart disease.
KW - MRI
KW - finite element modeling
KW - maximum isometric tension
KW - numerical optimization
KW - transmural variation
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U2 - 10.1115/1.4034558
DO - 10.1115/1.4034558
M3 - Article
C2 - 27591094
AN - SCOPUS:84994045682
SN - 0148-0731
VL - 138
JO - Journal of Biomechanical Engineering
JF - Journal of Biomechanical Engineering
IS - 11
M1 - 114501
ER -