title: Patient-Specific Computational Analysis of Ventricular Mechanics in Pulmonary Arterial Hypertension.
abstract: Patient-specific biventricular computational models associated with a normal subject and a pulmonary arterial hypertension (PAH) patient were developed to investigate the disease effects on ventricular mechanics. These models were developed using geometry reconstructed from magnetic resonance (MR) images, and constitutive descriptors of passive and active mechanics in cardiac tissues. Model parameter values associated with ventricular mechanical properties and myofiber architecture were obtained by fitting the models with measured pressure-volume loops and circumferential strain calculated from MR images using a hyperelastic warping method. Results show that the peak right ventricle (RV) pressure was substantially higher in the PAH patient (65 mmHg versus 20 mmHg), who also has a significantly reduced ejection fraction (EF) in both ventricles (left ventricle (LV): 39% versus 66% and RV: 18% versus 64%). Peak systolic circumferential strain was comparatively lower in both the left ventricle (LV) and RV free wall (RVFW) of the PAH patient (LV: -6.8% versus -13.2% and RVFW: -2.1% versus -9.4%). Passive stiffness, contractility, and myofiber stress in the PAH patient were all found to be substantially increased in both ventricles, whereas septum wall in the PAH patient possessed a smaller curvature than that in the LV free wall. Simulations using the PAH model revealed an approximately linear relationship between the septum curvature and the transseptal pressure gradient at both early-diastole and end-systole. These findings suggest that PAH can induce LV remodeling, and septum curvature measurements may be useful in quantifying transseptal pressure gradient in PAH patients.
authors: Department of Mechanical Engineering, Michigan State University, East Lansing, MI 48824-1226.
authors: Ce
authors: C
authors: Xi
authors: Department of Mechanical Engineering, Michigan State University, East Lansing, MI 48824-1226.
authors: Candace
authors: C
authors: Latnie
authors: National Heart Center Singapore, Singapore, Singapore 169609.
authors: Xiaodan
authors: X
authors: Zhao
authors: National Heart Center Singapore, Singapore, Singapore 169609.
authors: Ju Le
authors: JL
authors: Tan
authors: Simula Research Laboratory, Fornebu 1364, Norway.
authors: Samuel T
authors: ST
authors: Wall
authors: LMS, École Polytechnique, CNRS, Université Paris-Saclay; Inria, Université Paris-Saclay, Palaiseau 91128, France.
authors: Martin
authors: M
authors: Genet
authors: National Heart Center Singapore, Singapore, Singapore 169609;Duke-NUS Medical School, Singapore, Singapore 169857.
authors: Liang
authors: L
authors: Zhong
authors: Department of Mechanical Engineering, Michigan State University, East Lansing, MI 48824-1226 e-mail: lclee@egr.msu.edu.
authors: Lik Chuan
authors: LC
authors: Lee
mesh_terms: D000328:Adult; D001794:Blood Pressure; D019245:Compressive Strength; D003198:Computer Simulation; D004452:Echocardiography / Q000379:methods; D055119:Elastic Modulus; D006801:Humans; D006976:Hypertension, Pulmonary / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008297:Male; D008955:Models, Cardiovascular; D009200:Myocardial Contraction; D011651:Pulmonary Artery / Q000000981:diagnostic imaging / Q000503:physiopathology*; D013718:Tensile Strength; D018754:Ventricular Dysfunction / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology*