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Cardiac valve computational fluid dynamics

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https://www.readbyqxmd.com/read/28744840/organ-dynamics-and-fluid-dynamics-of-the-hh25-chick-embryonic-cardiac-ventricle-as-revealed-by-a-novel-4d-high-frequency-ultrasound-imaging-technique-and-computational-flow-simulations
#1
Sheldon Ho, Germaine Xin Yi Tan, Toon Jin Foo, Nhan Phan-Thien, Choon Hwai Yap
Past literature has provided evidence that a normal mechanical force environment of blood flow may guide normal development while an abnormal environment can lead to congenital malformations, thus warranting further studies on embryonic cardiovascular flow dynamics. In the current study, we developed a non-invasive 4D high-frequency ultrasound technique, and use it to analyze cardiovascular organ dynamics and flow dynamics. Three chick embryos at stage HH25 were scanned with high frequency ultrasound in cine-B-mode at multiple planes spaced at 0...
October 2017: Annals of Biomedical Engineering
https://www.readbyqxmd.com/read/28742031/patient-specific-left-ventricular-flow-simulations-from-transthoracic-echocardiography-robustness-evaluation-and-validation-against-ultrasound-doppler-and-magnetic-resonance-imaging
#2
David Larsson, Jeannette H Spuhler, Sven Petersson, Tim Nordenfur, Massimiliano Colarieti-Tosti, Johan Hoffman, Reidar Winter, Matilda Larsson
The combination of medical imaging with computational fluid dynamics (CFD) has enabled the study of 3D blood flow on a patient-specific level. However, with models based on gated high-resolution data, the study of transient flows, and any model implementation into routine cardiac care, is challenging. The present paper presents a novel pathway for patient-specific CFD modelling of the left ventricle (LV), using 4D transthoracic echocardiography (TTE) as input modality. To evaluate the clinical usability, two sub-studies were performed...
July 21, 2017: IEEE Transactions on Medical Imaging
https://www.readbyqxmd.com/read/28694784/4d-flow-analysis-of-bav-related-fluid-dynamic-alterations-evidences-of-wall-shear-stress-alterations-in-absence-of-clinically-relevant-aortic-anatomical-remodeling
#3
Filippo Piatti, Francesco Sturla, Malenka M Bissell, Selene Pirola, Massimo Lombardi, Igor Nesteruk, Alessandro Della Corte, Alberto C L Redaelli, Emiliano Votta
Bicuspid aortic valve (BAV) is the most common congenital cardiac disease and is a foremost risk factor for aortopathies. Despite the genetic basis of BAV and of the associated aortopathies, BAV-related alterations in aortic fluid-dynamics, and particularly in wall shear stresses (WSSs), likely play a role in the progression of aortopathy, and may contribute to its pathogenesis. To test whether WSS may trigger aortopathy, in this study we used 4D Flow sequences of phase-contrast cardiac magnetic resonance imaging (CMR) to quantitatively compare the in vivo fluid dynamics in the thoracic aorta of two groups of subjects: (i) five prospectively enrolled young patients with normo-functional BAV and with no aortic dilation and (ii) ten age-matched healthy volunteers...
2017: Frontiers in Physiology
https://www.readbyqxmd.com/read/28483261/computational-fluid-dynamics-simulation-of-the-right-subclavian-artery-cannulation
#4
Satoshi Numata, Keiichi Itatani, Hidetake Kawajiri, Sachiko Yamazaki, Keiichi Kanda, Hitoshi Yaku
OBJECTIVE: The purpose of this study was to evaluate the efficacy of right subclavian artery cannulation using computational fluid dynamics. METHODS: Patient-specific models of the aortic arch were made with 4 patterns (1: normal aorta, 2: ascending aorta aneurysm, 3: distal arch aneurysm, 4: bovine arch) based on the computed tomography images. Right subclavian artery and ascending aorta cannulation models were created to simulate the physiologic pulsatile flow...
August 2017: Journal of Thoracic and Cardiovascular Surgery
https://www.readbyqxmd.com/read/28276071/cfd-and-bernoulli-based-pressure-drop-estimates-a-comparison-using-patient-anatomies-from-heart-and-aortic-valve-segmentation-of-ct-images
#5
Jürgen Weese, Angela Lungu, Jochen Peters, Frank M Weber, Irina Waechter-Stehle, D Rodney Hose
PURPOSE: An aortic valve stenosis is an abnormal narrowing of the aortic valve (AV). It impedes blood flow and is often quantified by the geometric orifice area of the AV (AVA) and the pressure drop (PD). Using the Bernoulli equation, a relation between the PD and the effective orifice area (EOA) represented by the area of the vena contracta (VC) downstream of the AV can be derived. We investigate the relation between the AVA and the EOA using patient anatomies derived from cardiac computed tomography (CT) angiography images and computational fluid dynamic (CFD) simulations...
March 9, 2017: Medical Physics
https://www.readbyqxmd.com/read/28013289/impact-of-synthetic-elements-on-aortic-root-haemodynamics-computed-fluid-dynamics-of-aortic-root-reconstruction-and-valve-reimplantation
#6
Denis Berdajs, Selim Mosbahi, Francesco Strano, Zalan Forro, Marco Burki, Ludwig K von Segesser
Objectives: The aim was to evaluate the impact of the aortic valve reimplantation (David) and of the aortic root (AoR) remodelling (Yacoub) on the AoR haemodynamics. Methods: In an experimental setup where the clinical scenario of Yacoub, ( n =  5, domestic pig) and of David ( n =  5, domestic pig) procedure was performed in each AoR, six high-fidelity (200 Hz) sonomicrometric crystals were implanted. Crystals were positioned at three commissures with their projection at the root base...
March 1, 2017: European Journal of Cardio-thoracic Surgery
https://www.readbyqxmd.com/read/27873180/pledget-armed-sutures-affect-the-haemodynamic-performance-of-biologic-aortic-valve-substitutes-a-preliminary-experimental-and-computational-study
#7
Claudio Capelli, Chiara Corsini, Dario Biscarini, Francesco Ruffini, Francesco Migliavacca, Alfred Kocher, Guenther Laufer, Andrew M Taylor, Silvia Schievano, Martin Andreas, Gaetano Burriesci, Claus Rath
Surgical aortic valve replacement is the most common procedure of choice for the treatment of severe aortic stenosis. Bioprosthetic valves are traditionally sewed-in the aortic root by means of pledget-armed sutures during open-heart surgery. Recently, novel bioprostheses which include a stent-based anchoring system have been introduced to allow rapid implantation, therefore reducing the duration and invasiveness of the intervention. Different effects on the hemodynamics were clinically reported associated with the two technologies...
March 2017: Cardiovascular Engineering and Technology
https://www.readbyqxmd.com/read/27866678/patient-specific-cfd-models-for-intraventricular-flow-analysis-from-3d-ultrasound-imaging-comparison-of-three-clinical-cases
#8
COMPARATIVE STUDY
A M Bavo, A M Pouch, J Degroote, J Vierendeels, J H Gorman, R C Gorman, P Segers
BACKGROUND: As the intracardiac flow field is affected by changes in shape and motility of the heart, intraventricular flow features can provide diagnostic indications. Ventricular flow patterns differ depending on the cardiac condition and the exploration of different clinical cases can provide insights into how flow fields alter in different pathologies. METHODS: In this study, we applied a patient-specific computational fluid dynamics model of the left ventricle and mitral valve, with prescribed moving boundaries based on transesophageal ultrasound images for three cardiac pathologies, to verify the abnormal flow patterns in impaired hearts...
January 4, 2017: Journal of Biomechanics
https://www.readbyqxmd.com/read/27863744/towards-the-improved-quantification-of-in-vivo-abnormal-wall-shear-stresses-in-bav-affected-patients-from-4d-flow-imaging-benchmarking-and-application-to-real-data
#9
F Piatti, S Pirola, M Bissell, I Nesteruk, F Sturla, A Della Corte, A Redaelli, E Votta
Bicuspid aortic valve (BAV), i.e. the fusion of two aortic valve cusps, is the most frequent congenital cardiac malformation. Its progression is often characterized by accelerated leaflet calcification and aortic wall dilation. These processes are likely enhanced by altered biomechanical stimuli, including fluid-dynamic wall shear stresses (WSS) acting on both the aortic wall and the aortic valve. Several studies have proposed the exploitation of 4D-flow magnetic resonance imaging sequences to characterize abnormal in vivo WSS in BAV-affected patients, to support prognosis and timing of intervention...
January 4, 2017: Journal of Biomechanics
https://www.readbyqxmd.com/read/27863743/in-vitro-and-in-silico-approaches-to-quantify-the-effects-of-the-mitraclip-%C3%A2-system-on-mitral-valve-function
#10
Francesco Sturla, Riccardo Vismara, Michal Jaworek, Emiliano Votta, Paolo Romitelli, Omar A Pappalardo, Federico Lucherini, Carlo Antona, Gianfranco B Fiore, Alberto Redaelli
Mitraclip(®) implantation is widely used as a valid alternative to conventional open-chest surgery in high-risk patients with severe mitral valve (MV) regurgitation. Although effective in reducing mitral regurgitation (MR) in the majority of cases, the clip implantation produces a double-orifice area that can result in altered MV biomechanics, particularly in term of hemodynamics and mechanical stress distribution on the leaflets. In this scenario, we combined the consistency of in vitro experimental platforms with the versatility of numerical simulations to investigate clip impact on MV functioning...
January 4, 2017: Journal of Biomechanics
https://www.readbyqxmd.com/read/27844463/fluid-structure-interaction-study-of-transcatheter-aortic-valve-dynamics-using-smoothed-particle-hydrodynamics
#11
Wenbin Mao, Kewei Li, Wei Sun
Computational modeling of heart valve dynamics incorporating both fluid dynamics and valve structural responses has been challenging. In this study, we developed a novel fully-coupled fluid-structure interaction (FSI) model using smoothed particle hydrodynamics (SPH). A previously developed nonlinear finite element (FE) model of transcatheter aortic valves (TAV) was utilized to couple with SPH to simulate valve leaflet dynamics throughout the entire cardiac cycle. Comparative simulations were performed to investigate the impact of using FE-only models vs...
December 2016: Cardiovascular Engineering and Technology
https://www.readbyqxmd.com/read/27796137/two-dimensional-intraventricular-flow-pattern-visualization-using-the-image-based-computational-fluid-dynamics
#12
Siamak N Doost, Liang Zhong, Boyang Su, Yosry S Morsi
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...
April 2017: Computer Methods in Biomechanics and Biomedical Engineering
https://www.readbyqxmd.com/read/27618494/patient-specific-simulation-of-cardiac-blood-flow-from-high-resolution-ct
#13
Jonas Lantz, Lilian Henriksson, Anders Persson, Matts Karlsson, Tino Ebbers
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...
September 12, 2016: Journal of Biomechanical Engineering
https://www.readbyqxmd.com/read/27612951/patient-specific-cfd-simulation-of-intraventricular-haemodynamics-based-on-3d-ultrasound-imaging
#14
A M Bavo, A M Pouch, J Degroote, J Vierendeels, J H Gorman, R C Gorman, P Segers
BACKGROUND: The goal of this paper is to present a computational fluid dynamic (CFD) model with moving boundaries to study the intraventricular flows in a patient-specific framework. Starting from the segmentation of real-time transesophageal echocardiographic images, a CFD model including the complete left ventricle and the moving 3D mitral valve was realized. Their motion, known as a function of time from the segmented ultrasound images, was imposed as a boundary condition in an Arbitrary Lagrangian-Eulerian framework...
September 9, 2016: Biomedical Engineering Online
https://www.readbyqxmd.com/read/27547548/computational-fluid-dynamics-modelling-of-left-valvular-heart-diseases-during-atrial-fibrillation
#15
Stefania Scarsoglio, Andrea Saglietto, Fiorenzo Gaita, Luca Ridolfi, Matteo Anselmino
BACKGROUND: Although atrial fibrillation (AF), a common arrhythmia, frequently presents in patients with underlying valvular disease, its hemodynamic contributions are not fully understood. The present work aimed to computationally study how physical conditions imposed by pathologic valvular anatomy act on AF hemodynamics. METHODS: We simulated AF with different severity grades of left-sided valvular diseases and compared the cardiovascular effects that they exert during AF, compared to lone AF...
2016: PeerJ
https://www.readbyqxmd.com/read/27367143/the-impact-of-cardiac-motion-on-aortic-valve-flow-used-in-computational-simulations-of-the-thoracic-aorta
#16
David C Wendell, Margaret M Samyn, Joseph R Cava, Mary M Krolikowski, John F LaDisa
Advancements in image-based computational modeling are producing increasingly more realistic representations of vasculature and hemodynamics, but so far have not compensated for cardiac motion when imposing inflow boundary conditions. The effect of cardiac motion on aortic flow is important when assessing sequelae in this region including coarctation of the aorta (CoA) or regurgitant fraction. The objective of this investigation was to develop a method to assess and correct for the influence of cardiac motion on blood flow measurements through the aortic valve (AoV) and to determine its impact on patient-specific local hemodynamics quantified by computational fluid dynamics (CFD)...
September 1, 2016: Journal of Biomechanical Engineering
https://www.readbyqxmd.com/read/27073110/image-based-simulations-show-important-flow-fluctuations-in-a-normal-left-ventricle-what-could-be-the-implications
#17
C Chnafa, S Mendez, F Nicoud
Intra-cardiac flow has been explored for decades but there is still no consensus on whether or not healthy left ventricles (LV) may harbour turbulent-like flow despite its potential physiological and clinical relevance. The purpose of this study is to elucidate if a healthy LV could harbour flow instabilities, using image-based computational fluid dynamics (CFD). 35 cardiac cycles were simulated in a patient-specific left heart model obtained from cardiovascular magnetic resonance (CMR). The model includes the valves, atrium, ventricle, papillary muscles and ascending aorta...
November 2016: Annals of Biomedical Engineering
https://www.readbyqxmd.com/read/26968855/a-computational-framework-for-personalized-blood-flow-analysis-in-the-human-left-atrium
#18
Tomohiro Otani, Abdullah Al-Issa, Amir Pourmorteza, Elliot R McVeigh, Shigeo Wada, Hiroshi Ashikaga
Atrial fibrillation (AF), the most common human arrhythmia, is a marker of an increased risk of embolic stroke. However, recent studies suggest that AF may not be mechanistically responsible for the stroke events. An alternative explanation for the mechanism of intracardiac thrombosis and stroke in patients with AF is structural remodeling of the left atrium (LA). Nevertheless, a mechanistic link between LA structural remodeling and intracardiac thrombosis is unclear, because there is no clinically feasible methodology to evaluate the complex relationship between these two phenomena in individual patients...
November 2016: Annals of Biomedical Engineering
https://www.readbyqxmd.com/read/26951951/immersed-boundary-finite-element-model-of-fluid-structure-interaction-in-the-aortic-root
#19
Vittoria Flamini, Abe DeAnda, Boyce E Griffith
It has long been recognized that aortic root elasticity helps to ensure efficient aortic valve closure, but our understanding of the functional importance of the elasticity and geometry of the aortic root continues to e-volve as increasingly detailed in vivo imaging data become available. Herein, we describe a fluid-structure interaction model of the aortic root, including the aortic valve leaflets, the sinsuses of Valsalva, the aortic annulus, and the sinotubular junction, that employs a version of Peskin's immersed boundary (IB) method with a finite element (FE) description of the structural elasticity...
April 2016: Theoretical and Computational Fluid Dynamics
https://www.readbyqxmd.com/read/26792930/aortic-root-haemodynamics-following-david-procedure-numerical-analysis-of-3-dimensional-haemodynamics
#20
Denis Berdajs, Selim Mosbahi, Zalan Forro, Marco Burki, Ludwig K von Segesser
OBJECTIVES: The aim was to determine 3-dimensional (3D) geometrical deformation of the aortic root (AoR) following the David procedure in order to evaluate local haemodynamical conditions of individual AoR elements. METHODS: In the experimental set-up, the David procedure was performed on 10 domestic pigs. Data were compared with the measurements obtained in 10 native AoRs. In each AoR, six high-resolution ultrasonometric crystals (200 Hz) were implanted, being positioned at each commissure and at the AoR base...
June 2016: European Journal of Cardio-thoracic Surgery
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