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Duman ZM, Apaydın Z, Can İ, Kaplan MC, Buğra AK, Timur B, Bayram M, Karakurt ST, Güler GB, Kadiroğulları E, Onan B. Impact of Bileaflet Mechanical Mitral Valve Orientation on Pannus Overgrowth. INNOVATIONS-TECHNOLOGY AND TECHNIQUES IN CARDIOTHORACIC AND VASCULAR SURGERY 2023; 18:466-471. [PMID: 37705309 DOI: 10.1177/15569845231199100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/15/2023]
Abstract
OBJECTIVE Pannus overgrowth is a chronic inflammatory process that can cause valve dysfunction and threaten the durability of prosthetic valves. Bileaflet mechanical mitral valve can be implanted in either an anatomical (parallel to the anatomical axis) or nonanatomical (perpendicular or oblique to the anatomical axis) orientation. The effect of the rotational orientation of the bileaflet mechanical mitral valve on excessive pannus enlargement is unknown. The present study compared the effect of bileaflet mechanical mitral valve orientation on pannus overgrowth. METHODS The study included patients who underwent bileaflet mechanical mitral valve replacement for rheumatic mitral valve stenosis. The pannus formation was confirmed by reexamining all transesophageal echocardiography images in the picture archiving and communication systems between May 2017 and April 2021. The primary aim of this study was the development of pannus overgrowth. Patients were divided into 2 groups based on their implantation orientation of the bileaflet mechanical mitral valve. RESULTS Pannus overgrowth was found in 26 patients (56.5%) in the anatomical orientation group and 71 patients (74.7%) in the nonanatomical orientation group (P = 0.03). Anatomical orientation reduced the development of pannus overgrowth (odds ratio [OR] = 0.39, P = 0.04), and double left heart valve replacement increased the development of pannus overgrowth (OR = 2.73, P = 0.04). CONCLUSIONS Pannus overgrowth was less common in bileaflet mechanical mitral valves implanted in the anatomical orientation.
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Affiliation(s)
- Zihni Mert Duman
- Department of Cardiovascular Surgery, University of Health Sciences, Istanbul Mehmet Akif Ersoy Thoracic and Cardiovascular Surgery Hospital, Turkey
| | - Zinar Apaydın
- Department of Cardiovascular Surgery, University of Health Sciences, Istanbul Mehmet Akif Ersoy Thoracic and Cardiovascular Surgery Hospital, Turkey
| | - İsa Can
- Department of Cardiovascular Surgery, University of Health Sciences, Istanbul Mehmet Akif Ersoy Thoracic and Cardiovascular Surgery Hospital, Turkey
| | - Mustafa Can Kaplan
- Department of Cardiovascular Surgery, University of Health Sciences, Istanbul Mehmet Akif Ersoy Thoracic and Cardiovascular Surgery Hospital, Turkey
| | - Abdül Kerim Buğra
- Department of Cardiovascular Surgery, University of Health Sciences, Istanbul Mehmet Akif Ersoy Thoracic and Cardiovascular Surgery Hospital, Turkey
| | - Barış Timur
- Department of Cardiovascular Surgery, University of Health Sciences, Istanbul Mehmet Akif Ersoy Thoracic and Cardiovascular Surgery Hospital, Turkey
| | - Muhammed Bayram
- Department of Cardiovascular Surgery, University of Health Sciences, Istanbul Mehmet Akif Ersoy Thoracic and Cardiovascular Surgery Hospital, Turkey
| | - Seda Tükenmez Karakurt
- Department of Cardiology, University of Health Sciences, Istanbul Mehmet Akif Ersoy Thoracic and Cardiovascular Surgery Hospital, Turkey
| | - Gamze Babür Güler
- Department of Cardiology, University of Health Sciences, Istanbul Mehmet Akif Ersoy Thoracic and Cardiovascular Surgery Hospital, Turkey
| | - Ersin Kadiroğulları
- Department of Cardiovascular Surgery, University of Health Sciences, Istanbul Mehmet Akif Ersoy Thoracic and Cardiovascular Surgery Hospital, Turkey
| | - Burak Onan
- Department of Cardiovascular Surgery, University of Health Sciences, Istanbul Mehmet Akif Ersoy Thoracic and Cardiovascular Surgery Hospital, Turkey
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2
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Chen A, Basri AAB, Ismail NB, Tamagawa M, Zhu D, Ahmad KA. Simulation of Mechanical Heart Valve Dysfunction and the Non-Newtonian Blood Model Approach. Appl Bionics Biomech 2022; 2022:9612296. [PMID: 35498142 PMCID: PMC9042627 DOI: 10.1155/2022/9612296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 03/07/2022] [Accepted: 03/14/2022] [Indexed: 11/17/2022] Open
Abstract
The mechanical heart valve (MHV) is commonly used for the treatment of cardiovascular diseases. Nonphysiological hemodynamic in the MHV may cause hemolysis, platelet activation, and an increased risk of thromboembolism. Thromboembolism may cause severe complications and valve dysfunction. This paper thoroughly reviewed the simulation of physical quantities (velocity distribution, vortex formation, and shear stress) in healthy and dysfunctional MHV and reviewed the non-Newtonian blood flow characteristics in MHV. In the MHV numerical study, the dysfunction will affect the simulation results, increase the pressure gradient and shear stress, and change the blood flow patterns, increasing the risks of hemolysis and platelet activation. The blood flow passes downstream and has obvious recirculation and stagnation region with the increased dysfunction severity. Due to the complex structure of the MHV, the non-Newtonian shear-thinning viscosity blood characteristics become apparent in MHV simulations. The comparative study between Newtonian and non-Newtonian always shows the difference. The shear-thinning blood viscosity model is the basics to build the blood, also the blood exhibiting viscoelastic properties. More details are needed to establish a complete and more realistic simulation.
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Affiliation(s)
- Aolin Chen
- Faculty of Engineering, Universiti Putra Malaysia, Serdang, Selangor 43400, Malaysia
| | - Adi Azriff Bin Basri
- Faculty of Engineering, Universiti Putra Malaysia, Serdang, Selangor 43400, Malaysia
| | - Norzian Bin Ismail
- Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor 43400, Malaysia
| | - Masaaki Tamagawa
- Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, Kitakyushu, Fukuoka 804-8550, Japan
| | - Di Zhu
- Faculty of Engineering, Universiti Putra Malaysia, Serdang, Selangor 43400, Malaysia
| | - Kamarul Arifin Ahmad
- Faculty of Engineering, Universiti Putra Malaysia, Serdang, Selangor 43400, Malaysia
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3
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Xu F, Kenjereš S. Numerical simulations of flow patterns in the human left ventricle model with a novel dynamic mesh morphing approach based on radial basis function. Comput Biol Med 2021; 130:104184. [PMID: 33444850 DOI: 10.1016/j.compbiomed.2020.104184] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 12/15/2020] [Accepted: 12/15/2020] [Indexed: 10/22/2022]
Abstract
We present a new numerical simulation framework for prediction of flow patterns in the human left ventricle model. In this study, a radial basis function (RBF) mesh morphing method is developed and applied within the finite-volume computational fluid dynamics (CFD) approach. The numerical simulations are designed to closely mimic details of recent tomographic particle image velocimetry (TomoPIV) experiments. The numerically simulated dynamic motions of the left ventricle and tri-leaflet biological mitral valve are emulated through the RBF morphing method. The arbitrary Lagrangian-Eulerian (ALE) based CFD is performed with the RBF-defined deforming wall boundaries. The results obtained show a good agreement with experiments, confirming the reliability and accuracy of the developed simulation framework.
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Affiliation(s)
- Fei Xu
- Department of Chemical Engineering, Faculty of Applied Sciences, Delft University of Technology and J. M. Burgerscentrum Research School for Fluid Mechanics, Van der Maasweg 9, 2629 HZ, Delft, the Netherlands
| | - Saša Kenjereš
- Department of Chemical Engineering, Faculty of Applied Sciences, Delft University of Technology and J. M. Burgerscentrum Research School for Fluid Mechanics, Van der Maasweg 9, 2629 HZ, Delft, the Netherlands.
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4
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Lantz J, Bäck S, Carlhäll CJ, Bolger A, Persson A, Karlsson M, Ebbers T. Impact of prosthetic mitral valve orientation on the ventricular flow field: Comparison using patient-specific computational fluid dynamics. J Biomech 2020; 116:110209. [PMID: 33422725 DOI: 10.1016/j.jbiomech.2020.110209] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 12/10/2020] [Accepted: 12/14/2020] [Indexed: 11/29/2022]
Abstract
Significant mitral valve regurgitation creates progressive adverse remodeling of the left ventricle (LV). Replacement of the failing valve with a prosthesis generally improves patient outcomes but leaves the patient with non-physiological intracardiac flow patterns that might contribute to their future risk of thrombus formation and embolism. It has been suggested that the angular orientation of the implanted valve might modify the postoperative distortion of the intraventricular flow field. In this study, we investigated the effect of prosthetic valve orientation on LV flow patterns by using heart geometry from a patient with LV dysfunction and a competent native mitral valve to calculate intracardiac flow fields with computational fluid dynamics (CFD). Results were validated using in vivo 4D Flow MRI. The computed flow fields were compared to calculations following virtual implantation of a mechanical heart valve oriented in four different angles to assess the effect of leaflet position. Flow patterns were visualized in long- and short-axes and quantified with flow component analysis. In comparison to a native valve, valve implantation increased the proportion of the mitral inflow remaining in the basal region and further increased the residual volume in the apical area. Only slight changes due to valve orientation were observed. Using our numerical framework, we demonstrated quantitative changes in left ventricular blood flow due to prosthetic mitral replacement. This framework may be used to improve design of prosthetic heart valves and implantation procedures to minimize the potential for apical flow stasis, and potentially assist personalized treatment planning.
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Affiliation(s)
- Jonas Lantz
- Division of Cardiovascular Medicine, Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden; Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden
| | - Sophia Bäck
- Division of Cardiovascular Medicine, Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden; Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden
| | - Carl-Johan Carlhäll
- Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden; Department of Clinical Physiology in Linköping, and Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden
| | - Ann Bolger
- Department of Clinical Physiology in Linköping, and Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden; Department of Medicine, University of California, San Francisco, United States
| | - Anders Persson
- Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden; Division of Radiology, Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden
| | - Matts Karlsson
- Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden; Division of Applied Thermodynamics and Fluid Mechanics, Department of Management and Engineering, Linköping University, Sweden
| | - Tino Ebbers
- Division of Cardiovascular Medicine, Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden; Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden.
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5
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Feng L, Qi N, Gao H, Sun W, Vazquez M, Griffith BE, Luo X. On the chordae structure and dynamic behaviour of the mitral valve. IMA JOURNAL OF APPLIED MATHEMATICS 2018; 83:1066-1091. [PMID: 30655652 PMCID: PMC6328065 DOI: 10.1093/imamat/hxy035] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Revised: 06/29/2018] [Accepted: 07/29/2018] [Indexed: 05/07/2023]
Abstract
We develop a fluid-structure interaction (FSI) model of the mitral valve (MV) that uses an anatomically and physiologically realistic description of the MV leaflets and chordae tendineae. Three different chordae models-complex, 'pseudo-fibre' and simplified chordae-are compared to determine how different chordae representations affect the dynamics of the MV. The leaflets and chordae are modelled as fibre-reinforced hyperelastic materials, and FSI is modelled using an immersed boundary-finite element method. The MV model is first verified under static boundary conditions against the commercial finite element software ABAQUS and then used to simulate MV dynamics under physiological pressure conditions. Interesting flow patterns and vortex formulation are observed in all three cases. To quantify the highly complex system behaviour resulting from FSI, an energy budget analysis of the coupled MV FSI model is performed. Results show that the complex and pseudo-fibre chordae models yield good valve closure during systole but that the simplified chordae model leads to poorer leaflet coaptation and an unrealistic bulge in the anterior leaflet belly. An energy budget analysis shows that the MV models with complex and pseudo-fibre chordae have similar energy distribution patterns but the MV model with the simplified chordae consumes more energy, especially during valve closing and opening. We find that the complex chordae and pseudo-fibre chordae have similar impact on the overall MV function but that the simplified chordae representation is less accurate. Because a pseudo-fibre chordal structure is easier to construct and less computationally intensive, it may be a good candidate for modelling MV dynamics or interaction between the MV and heart in patient-specific applications.
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Affiliation(s)
- Liuyang Feng
- School of Mathematics and Statistics, University of Glasgow, UK
| | - Nan Qi
- Institute of Marine Science and Technology, Shandong University, Shandong, China and School of Mathematics and Statistics, University of Glasgow, UK
| | - Hao Gao
- School of Mathematics and Statistics, University of Glasgow, UK
| | - Wei Sun
- Wallace H Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | | | - Boyce E Griffith
- Departments of Mathematics, Applied Physical Sciences, and Biomedical Engineering and McAllister Heart Institute, University of North Carolina, Chapel Hill, NC, USA
| | - Xiaoyu Luo
- School of Mathematics and Statistics, University of Glasgow, UK
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6
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Seo JH, Eslami P, Caplan J, Tamargo RJ, Mittal R. A Highly Automated Computational Method for Modeling of Intracranial Aneurysm Hemodynamics. Front Physiol 2018; 9:681. [PMID: 29946264 PMCID: PMC6005827 DOI: 10.3389/fphys.2018.00681] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 05/15/2018] [Indexed: 11/13/2022] Open
Abstract
Intracranial aneurysms manifest in a vast variety of morphologies and their growth and rupture risk are subject to patient-specific conditions that are coupled with complex, non-linear effects of hemodynamics. Thus, studies that attempt to understand and correlate rupture risk to aneurysm morphology have to incorporate hemodynamics, and at the same time, address a large enough sample size so as to produce reliable statistical correlations. In order to perform accurate hemodynamic simulations for a large number of aneurysm cases, automated methods to convert medical imaging data to simulation-ready configuration with minimal (or no) human intervention are required. In the present study, we develop a highly-automated method based on the immersed boundary method framework to construct computational models from medical imaging data which is the key idea is the direct use of voxelized contrast information from the 3D angiograms to construct a level-set based computational “mask” for the hemodynamic simulation. Appropriate boundary conditions are provided to the mask and the dynamics of blood flow inside the vessels and aneurysm is simulated by solving the Navier-Stokes equations on the Cartesian grid using the sharp-interface immersed boundary method. The present method does not require body conformal surface/volume mesh generation or other intervention for model clean-up. The viability of the proposed method is demonstrated for a number of distinct aneurysms derived from actual, patient-specific data.
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Affiliation(s)
- Jung-Hee Seo
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD, United States
| | - Parastou Eslami
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD, United States
| | - Justin Caplan
- Department of Neurosurgery, Johns Hopkins Medicine, Baltimore, MD, United States
| | - Rafael J Tamargo
- Department of Neurosurgery, Johns Hopkins Medicine, Baltimore, MD, United States
| | - Rajat Mittal
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD, United States
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7
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In Vitro Validation of a Numerical Simulation of Leaflet Kinematics in a Polymeric Aortic Valve Under Physiological Conditions. Cardiovasc Eng Technol 2018; 9:42-52. [DOI: 10.1007/s13239-018-0340-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 01/05/2018] [Indexed: 10/18/2022]
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8
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Lantz J, Henriksson L, Persson A, Karlsson M, Ebbers T. Patient-Specific Simulation of Cardiac Blood Flow From High-Resolution Computed Tomography. J Biomech Eng 2016; 138:2552968. [DOI: 10.1115/1.4034652] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Indexed: 11/08/2022]
Abstract
Cardiac hemodynamics can be computed from medical imaging data, and results could potentially aid in cardiac diagnosis and treatment optimization. However, simulations are often based on simplified geometries, ignoring features such as papillary muscles and trabeculae due to their complex shape, limitations in image acquisitions, and challenges in computational modeling. This severely hampers the use of computational fluid dynamics in clinical practice. The overall aim of this study was to develop a novel numerical framework that incorporated these geometrical features. The model included the left atrium, ventricle, ascending aorta, and heart valves. The framework used image registration to obtain patient-specific wall motion, automatic remeshing to handle topological changes due to the complex trabeculae motion, and a fast interpolation routine to obtain intermediate meshes during the simulations. Velocity fields and residence time were evaluated, and they indicated that papillary muscles and trabeculae strongly interacted with the blood, which could not be observed in a simplified model. The framework resulted in a model with outstanding geometrical detail, demonstrating the feasibility as well as the importance of a framework that is capable of simulating blood flow in physiologically realistic hearts.
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Affiliation(s)
- Jonas Lantz
- Department of Medical and Health Sciences, Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping SE-581 83, Sweden e-mail:
| | - Lilian Henriksson
- Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping SE-581 83, Sweden
| | - Anders Persson
- Department of Medical and Health Sciences, Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping SE-581 83, Sweden
| | - Matts Karlsson
- Department of Management and Engineering, Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping SE-581 83, Sweden
| | - Tino Ebbers
- Department of Medical and Health Sciences, Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping SE-581 83, Sweden
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9
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Doost SN, Zhong L, Su B, Morsi YS. Two-dimensional intraventricular flow pattern visualization using the image-based computational fluid dynamics. Comput Methods Biomech Biomed Engin 2016; 20:492-507. [PMID: 27796137 DOI: 10.1080/10255842.2016.1250891] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
The image-based computational fluid dynamics (IB-CFD) technique, as the combination of medical images and the CFD method, is utilized in this research to analyze the left ventricle (LV) hemodynamics. The research primarily aims to propose a semi-automated technique utilizing some freely available and commercial software packages in order to simulate the LV hemodynamics using the IB-CFD technique. In this research, moreover, two different physiological time-resolved 2D models of a patient-specific LV with two different types of aortic and mitral valves, including the orifice-type valves and integrated with rigid leaflets, are adopted to visualize the process of developing intraventricular vortex formation and propagation. The blood flow pattern over the whole cardiac cycle of two models is also compared to investigate the effect of utilizing different valve types in the process of the intraventricular vortex formation. Numerical findings indicate that the model with integrated valves can predict more complex intraventricular flow that can match better the physiological flow pattern in comparison to the orifice-type model.
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Affiliation(s)
- Siamak N Doost
- a Biomechanical and Tissue Engineering Lab, Faculty of Science, Engineering and Technology , Swinburne University of Technology , Melbourne , Australia
| | - Liang Zhong
- b National Heart Research Institute of Singapore , National Heart Centre , Singapore , Singapore.,c Duke-NUS Medical School , Singapore , Singapore
| | - Boyang Su
- b National Heart Research Institute of Singapore , National Heart Centre , Singapore , Singapore
| | - Yosry S Morsi
- a Biomechanical and Tissue Engineering Lab, Faculty of Science, Engineering and Technology , Swinburne University of Technology , Melbourne , Australia
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Okafor IU, Santhanakrishnan A, Raghav VS, Yoganathan AP. Role of Mitral Annulus Diastolic Geometry on Intraventricular Filling Dynamics. J Biomech Eng 2016; 137:121007. [PMID: 26502376 DOI: 10.1115/1.4031838] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Indexed: 11/08/2022]
Abstract
The mitral valve (MV) is a bileaflet valve positioned between the left atrium and ventricle of the heart. The annulus of the MV has been observed to undergo geometric changes during the cardiac cycle, transforming from a saddle D-shape during systole to a flat (and less eccentric) D-shape during diastole. Prosthetic MV devices, including heart valves and annuloplasty rings, are designed based on these two configurations, with the circular design of some prosthetic heart valves (PHVs) being an approximation of the less eccentric, flat D-shape. Characterizing the effects of these geometrical variations on the filling efficiency of the left ventricle (LV) is required to understand why the flat D-shaped annulus is observed in the native MV during diastole in addition to optimizing the design of prosthetic devices. We hypothesize that the D-shaped annulus reduces energy loss during ventricular filling. An experimental left heart simulator (LHS) consisting of a flexible-walled LV physical model was used to characterize the filling efficiency of the two mitral annular geometries. The strength of the dominant vortical structure formed and the energy dissipation rate (EDR) of the measured fields, during the diastolic period of the cardiac cycle, were used as metrics to quantify the filling efficiency. Our results indicated that the O-shaped annulus generates a stronger (25% relative to the D-shaped annulus) vortical structure than that of the D-shaped annulus. It was also found that the O-shaped annulus resulted in higher EDR values throughout the diastolic period of the cardiac cycle. The results support the hypothesis that a D-shaped mitral annulus reduces dissipative energy losses in ventricular filling during diastole and in turn suggests that a symmetric stent design does not provide lower filling efficiency than an equivalent asymmetric design.
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Vedula V, George R, Younes L, Mittal R. Hemodynamics in the Left Atrium and Its Effect on Ventricular Flow Patterns. J Biomech Eng 2016; 137:111003. [PMID: 26329022 DOI: 10.1115/1.4031487] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Indexed: 11/08/2022]
Abstract
In the present study, we investigate the hemodynamics inside left atrium (LA) and understand its impact on the development of ventricular flow patterns. We construct the heart model using dynamic-computed tomographic images and perform simulations using an immersed boundary method based flow solver. We show that the atrial hemodynamics is characterized by a circulatory flow generated by the left pulmonary veins (LPVs) and a direct stream from the right pulmonary veins (RPVs). The complex interaction of the vortex rings formed from each of the PVs leads to vortex breakup and annihilation, thereby producing a regularized flow at the mitral annulus. A comparison of the ventricular flow velocities between the physiological and a simplified pipe-based atrium model shows that the overall differences are limited to about 10% of the peak mitral flow velocity. The implications of this finding on the functional morphology of the left heart as well the computational and experimental modeling of ventricular hemodynamics are discussed.
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12
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Imanparast A, Fatouraee N, Sharif F. The impact of valve simplifications on left ventricular hemodynamics in a three dimensional simulation based on in vivo MRI data. J Biomech 2016; 49:1482-1489. [PMID: 27040387 DOI: 10.1016/j.jbiomech.2016.03.021] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Revised: 03/11/2016] [Accepted: 03/13/2016] [Indexed: 10/22/2022]
Abstract
Left ventricle (LV) fluid dynamics and the function of its valves have a crucial impact on clinical diagnosis, treatment and prosthesis design. In this paper, we simulated left ventricular flow using 3D computational fluid dynamics (CFD) based on geometrical and deformational information obtained from MRI. Time variant smoothed LV shapes were extracted from MR images. Corresponding deformation data was interpolated using a cubic-spline interpolation. To evaluate valve influence on LV flow, we compared two planar valve models: physiologically corrected gradually opening/closing model and a simple on/off model. Endocardial displacement was applied to fluid boundary using fluid-structure interaction (FSI) approach. Arbitrary Lagrangian-Eulerian (ALE) formulation was used for unsteady incompressible viscous Newtonian blood flow in the fluid domain. Comparison of results for LV flow with two valve models demonstrated a clear distinction between pressure distribution, velocity distribution, vortex formation/growth/vanishing and energy dissipation especially in the filling phase. Consequently, LV flow simulation by ignoring geometrical details of valves׳ model may lead to non-realistic results in some aspects.
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Affiliation(s)
- Ali Imanparast
- Department of Biomedical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Iran
| | - Nasser Fatouraee
- Department of Biomedical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Iran.
| | - Farhad Sharif
- Department of Polymer Engineering & Color Technology, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Iran
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13
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Choi YJ, Constantino J, Vedula V, Trayanova N, Mittal R. A New MRI-Based Model of Heart Function with Coupled Hemodynamics and Application to Normal and Diseased Canine Left Ventricles. Front Bioeng Biotechnol 2015; 3:140. [PMID: 26442254 PMCID: PMC4585083 DOI: 10.3389/fbioe.2015.00140] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 08/31/2015] [Indexed: 11/22/2022] Open
Abstract
A methodology for the simulation of heart function that combines an MRI-based model of cardiac electromechanics (CE) with a Navier–Stokes-based hemodynamics model is presented. The CE model consists of two coupled components that simulate the electrical and the mechanical functions of the heart. Accurate representations of ventricular geometry and fiber orientations are constructed from the structural magnetic resonance and the diffusion tensor MR images, respectively. The deformation of the ventricle obtained from the electromechanical model serves as input to the hemodynamics model in this one-way coupled approach via imposed kinematic wall velocity boundary conditions and at the same time, governs the blood flow into and out of the ventricular volume. The time-dependent endocardial surfaces are registered using a diffeomorphic mapping algorithm, while the intraventricular blood flow patterns are simulated using a sharp-interface immersed boundary method-based flow solver. The utility of the combined heart-function model is demonstrated by comparing the hemodynamic characteristics of a normal canine heart beating in sinus rhythm against that of the dyssynchronously beating failing heart. We also discuss the potential of coupled CE and hemodynamics models for various clinical applications.
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Affiliation(s)
- Young Joon Choi
- Department of Mechanical Engineering, Johns Hopkins University , Baltimore, MD , USA ; Institute for Computational Medicine, Johns Hopkins University , Baltimore, MD , USA
| | - Jason Constantino
- Institute for Computational Medicine, Johns Hopkins University , Baltimore, MD , USA ; Department of Biomedical Engineering, Johns Hopkins University , Baltimore, MD , USA
| | - Vijay Vedula
- Department of Mechanical Engineering, Johns Hopkins University , Baltimore, MD , USA
| | - Natalia Trayanova
- Institute for Computational Medicine, Johns Hopkins University , Baltimore, MD , USA ; Department of Biomedical Engineering, Johns Hopkins University , Baltimore, MD , USA
| | - Rajat Mittal
- Department of Mechanical Engineering, Johns Hopkins University , Baltimore, MD , USA ; Institute for Computational Medicine, Johns Hopkins University , Baltimore, MD , USA
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14
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Su B, Kabinejadian F, Phang HQ, Kumar GP, Cui F, Kim S, Tan RS, Hon JKF, Allen JC, Leo HL, Zhong L. Numerical Modeling of Intraventricular Flow during Diastole after Implantation of BMHV. PLoS One 2015; 10:e0126315. [PMID: 25961285 PMCID: PMC4427484 DOI: 10.1371/journal.pone.0126315] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Accepted: 03/31/2015] [Indexed: 12/20/2022] Open
Abstract
This work presents a numerical simulation of intraventricular flow after the implantation of a bileaflet mechanical heart valve at the mitral position. The left ventricle was simplified conceptually as a truncated prolate spheroid and its motion was prescribed based on that of a healthy subject. The rigid leaflet rotation was driven by the transmitral flow and hence the leaflet dynamics were solved using fluid-structure interaction approach. The simulation results showed that the bileaflet mechanical heart valve at the mitral position behaved similarly to that at the aortic position. Sudden area expansion near the aortic root initiated a clockwise anterior vortex, and the continuous injection of flow through the orifice resulted in further growth of the anterior vortex during diastole, which dominated the intraventricular flow. This flow feature is beneficial to preserving the flow momentum and redirecting the blood flow towards the aortic valve. To the best of our knowledge, this is the first attempt to numerically model intraventricular flow with the mechanical heart valve incorporated at the mitral position using a fluid-structure interaction approach. This study facilitates future patient-specific studies.
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Affiliation(s)
- Boyang Su
- National Heart Research Institute of Singapore, National Heart Centre Singapore, Singapore, Singapore
| | - Foad Kabinejadian
- Department of Biomedical Engineering, National University of Singapore, Singapore, Singapore
| | - Hui Qun Phang
- Department of Surgery, National University of Singapore, Singapore, Singapore
| | | | - Fangsen Cui
- Institute of High Performance Computing, ASTAR, Singapore, Singapore
| | - Sangho Kim
- Department of Biomedical Engineering, National University of Singapore, Singapore, Singapore
| | - Ru San Tan
- National Heart Research Institute of Singapore, National Heart Centre Singapore, Singapore, Singapore
| | - Jimmy Kim Fatt Hon
- Department of Surgery, National University of Singapore, Singapore, Singapore
| | | | - Hwa Liang Leo
- Department of Biomedical Engineering, National University of Singapore, Singapore, Singapore
| | - Liang Zhong
- National Heart Research Institute of Singapore, National Heart Centre Singapore, Singapore, Singapore
- Duke-NUS Graduate Medical School, Singapore, Singapore
- * E-mail:
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