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Fluid dynamics of the heart

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https://www.readbyqxmd.com/read/27905492/high-fidelity-computational-simulation-of-thrombus-formation-in-thoratec-heartmate-ii-continuous-flow-ventricular-assist-device
#1
Wei-Tao Wu, Fang Yang, Jingchun Wu, Nadine Aubry, Mehrdad Massoudi, James F Antaki
Continuous flow ventricular assist devices (cfVADs) provide a life-saving therapy for severe heart failure. However, in recent years, the incidence of device-related thrombosis (resulting in stroke, device-exchange surgery or premature death) has been increasing dramatically, which has alarmed both the medical community and the FDA. The objective of this study was to gain improved understanding of the initiation and progression of thrombosis in one of the most commonly used cfVADs, the Thoratec HeartMate II...
December 1, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27904980/a-resolved-two-way-coupled-cfd-6-dof-approach-for-predicting-embolus-transport-and-the-embolus-trapping-efficiency-of-ivc-filters
#2
Kenneth I Aycock, Robert L Campbell, Keefe B Manning, Brent A Craven
Inferior vena cava (IVC) filters are medical devices designed to provide a mechanical barrier to the passage of emboli from the deep veins of the legs to the heart and lungs. Despite decades of development and clinical use, IVC filters still fail to prevent the passage of all hazardous emboli. The objective of this study is to (1) develop a resolved two-way computational model of embolus transport, (2) provide verification and validation evidence for the model, and (3) demonstrate the ability of the model to predict the embolus-trapping efficiency of an IVC filter...
November 30, 2016: Biomechanics and Modeling in Mechanobiology
https://www.readbyqxmd.com/read/27878837/thrombotic-depositions-on-right-impeller-of-double-ended-centrifugal-total-artificial-heart-in-vivo
#3
Jamshid H Karimov, David J Horvath, Shinji Okano, Mark Goodin, Gengo Sunagawa, Nicole Byram, Nader Moazami, Leonard A R Golding, Kiyotaka Fukamachi
The development of total artificial heart devices is a complex undertaking that includes chronic biocompatibility assessment of the device. It is considered particularly important to assess whether device design and features can be compatible long term in a biological environment. As part of the development program for the Cleveland Clinic continuous-flow total artificial heart (CFTAH), we evaluated the device for signs of thrombosis and biological material deposition in four animals that had achieved the intended 14-, 30-, or 90-day durations in each respective experiment...
November 23, 2016: Artificial Organs
https://www.readbyqxmd.com/read/27873180/pledget-armed-sutures-affect-the-haemodynamic-performance-of-biologic-aortic-valve-substitutes-a-preliminary-experimental-and-computational-study
#4
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...
November 21, 2016: 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
#5
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...
November 11, 2016: 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
#6
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...
November 10, 2016: Journal of Biomechanics
https://www.readbyqxmd.com/read/27858374/prediction-of-fluid-responsiveness-an-update
#7
REVIEW
Xavier Monnet, Paul E Marik, Jean-Louis Teboul
In patients with acute circulatory failure, the decision to give fluids or not should not be taken lightly. The risk of overzealous fluid administration has been clearly established. Moreover, volume expansion does not always increase cardiac output as one expects. Thus, after the very initial phase and/or if fluid losses are not obvious, predicting fluid responsiveness should be the first step of fluid strategy. For this purpose, the central venous pressure as well as other "static" markers of preload has been used for decades, but they are not reliable...
December 2016: Annals of Intensive Care
https://www.readbyqxmd.com/read/27844463/fluid-structure-interaction-study-of-transcatheter-aortic-valve-dynamics-using-smoothed-particle-hydrodynamics
#8
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/27832045/proof-of-concept-of-an-endoscopic-sutureless-valve-sizer
#9
Marco Vola, Juan Pablo Maureira, Vito Giovanni Ruggieri, Jean-François Fuzellier, Salvatore Campisi, Jean-Pierre Favre, Antoine Gerbay, Thierry A Folliguet
OBJECTIVE: In this paper, we present an endoscopic expandable sizer conceived to allow thoracoscopic aortic valve replacement with a sutureless prosthesis using a dynamic sizing of the aortic annulus. METHODS: Ten aortic torsos were prepared using a five-trocar thoracoscopic setting. Once the aortotomy was performed and the aortic valve leaflets removed, the technical feasibility of the endoscopic sizing (introduction into the trocar, expansion into the aortic annulus, determination of the valve size, and retraction) with the device was assessed...
September 2016: Innovations: Technology and Techniques in Cardiothoracic and Vascular Surgery
https://www.readbyqxmd.com/read/27824560/assessing-the-performance-of-ultrafast-vector-flow-imaging-in-the-neonatal-heart-via-multiphysics-modeling-and-in-vitro-experiments
#10
Joris Van Cauwenberge, Lasse Lovstakken, Solveig Fadnes, Alfonso Rodriguez-Morales, Jan Vierendeels, Patrick Segers, Abigail Swillens
Ultrafast vector flow imaging would benefit newborn patients with congenital heart disorders, but still requires thorough validation before translation to clinical practice. This paper investigates 2-D speckle tracking (ST) of intraventricular blood flow in neonates when transmitting diverging waves at ultrafast frame rate. Computational and in vitro studies enabled us to quantify the performance and identify artifacts related to the flow and the imaging sequence. First, synthetic ultrasound images of a neonate's left ventricular flow pattern were obtained with the ultrasound simulator Field II by propagating point scatterers according to 3-D intraventricular flow fields obtained with computational fluid dynamics (CFD)...
November 2016: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
https://www.readbyqxmd.com/read/27815409/a-new-beating-heart-mitral-and-aortic-valve-assessment-model-with-implications-for-valve-intervention-training
#11
Wobbe Bouma, Jayant S Jainandunsing, Arash Khamooshian, Pim van der Harst, Massimo A Mariani, Ehsan Natour
OBJECTIVES: A thorough understanding of mitral and aortic valve motion dynamics is essential in mastering the skills necessary for performing successful valve intervention (open or transcatheter repair or replacement). We describe a reproducible and versatile beating-heart mitral and aortic valve assessment and valve intervention training model in human cadavers. METHODS: The model is constructed by bilateral ligation of the pulmonary veins, ligation of the supra-aortic arteries, creating a shunt between the descending thoracic aorta and the left atrial appendage with a vascular prosthesis, anastomizing a vascular prosthesis to the apex and positioning an intra-aortic balloon pump (IABP) in the vascular prosthesis, cross-clamping the descending thoracic aorta, and finally placing a fluid line in the shunt prosthesis...
November 3, 2016: Interactive Cardiovascular and Thoracic Surgery
https://www.readbyqxmd.com/read/27738801/goal-directed-fluid-therapy-decreases-postoperative-morbidity-but-not-mortality-in-major-non-cardiac-surgery-a-meta-analysis-and-trial-sequential-analysis-of-randomized-controlled-trials
#12
Anirban Som, Souvik Maitra, Sulagna Bhattacharjee, Dalim K Baidya
BACKGROUND AND AIMS: Optimum perioperative fluid administration may improve postoperative outcome after major surgery. This meta-analysis and systematic review has been aimed to determine the effect of dynamic goal directed fluid therapy (GDFT) on postoperative morbidity and mortality in non-cardiac surgical patients. MATERIAL AND METHODS: Meta-analysis of published prospective randomized controlled trials where GDFT based on non-invasive flow based hemodynamic measurement has been compared with a standard care...
October 13, 2016: Journal of Anesthesia
https://www.readbyqxmd.com/read/27663769/fluid-mechanics-of-human-fetal-right-ventricles-from-image-based-computational-fluid-dynamics-using-4d-clinical-ultrasound-scans
#13
Hadi Wiputra, Chang Quan Lai, Guat Ling Lim, Joel Jia Wei Heng, Lan Guo, Hwa Liang Leo, Sanah Merchant Soomar, Arijit Biswas, Citra Nurfarah Zaini Mattar, Choon Hwai Yap
0.6-1.9% of US children were born with congenital heart malformations. Clinical and animal studies suggests that abnormal blood flow forces might play a role in causing these malformation, highlighting the importance of understanding the fetal cardiovascular fluid mechanics. We performed Computational Fluid Dynamics simulations of the right ventricles, based on 4D ultrasound scans of three 20 weeks old normal human foetuses, to characterize their flow and energy dynamics. Peak intraventricular pressure gradients were found to be 0...
September 23, 2016: American Journal of Physiology. Heart and Circulatory Physiology
https://www.readbyqxmd.com/read/27659877/physiological-mechanisms-of-pulmonary-hypertension
#14
REVIEW
David H MacIver, Ismail Adeniran, Iain R MacIver, Alistair Revell, Henggui Zhang
Pulmonary hypertension is usually related to obstruction of pulmonary blood flow at the level of the pulmonary arteries (eg, pulmonary embolus), pulmonary arterioles (idiopathic pulmonary hypertension), pulmonary veins (pulmonary venoocclusive disease) or mitral valve (mitral stenosis and regurgitation). Pulmonary hypertension is also observed in heart failure due to left ventricle myocardial diseases regardless of the ejection fraction. Pulmonary hypertension is often regarded as a passive response to the obstruction to pulmonary flow...
October 2016: American Heart Journal
https://www.readbyqxmd.com/read/27618494/patient-specific-simulation-of-cardiac-blood-flow-from-high-resolution-ct
#15
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/27599255/diagnosis-and-treatment-of-lymphatic-plastic-bronchitis-in-adults-using-advanced-lymphatic-imaging-and-percutaneous-embolization
#16
Maxim G Itkin, Francis X McCormack, Yoav Dori
RATIONALE: Plastic bronchitis is a condition characterized by expectoration of branching bronchial casts. Although the mechanism of cast formation in adults with plastic bronchitis remains poorly understood, abnormal pulmonary lymphatic flow resulting in molding of congealing lymphatic fluids in the airway has been documented as a cause of the disease in children with congenital heart disease. OBJECTIVES: To use advanced lymphatic imaging techniques, including dynamic contrast-enhanced magnetic resonance (MR) lymphangiography (DCMRL) and intranodal lymphangiography, to investigate the mechanism of cast formation in adult patients with plastic bronchitis, and to evaluate the therapeutic outcome of percutaneous lymphatic embolization for these patients...
October 2016: Annals of the American Thoracic Society
https://www.readbyqxmd.com/read/27562639/heart-blood-flow-simulation-a-perspective-review
#17
REVIEW
Siamak N Doost, Dhanjoo Ghista, Boyang Su, Liang Zhong, Yosry S Morsi
Cardiovascular disease (CVD), the leading cause of death today, incorporates a wide range of cardiovascular system malfunctions that affect heart functionality. It is believed that the hemodynamic loads exerted on the cardiovascular system, the left ventricle (LV) in particular, are the leading cause of CVD initiation and propagation. Moreover, it is believed that the diagnosis and prognosis of CVD at an early stage could reduce its high mortality and morbidity rate. Therefore, a set of robust clinical cardiovascular assessment tools has been introduced to compute the cardiovascular hemodynamics in order to provide useful insights to physicians to recognize indicators leading to CVD and also to aid the diagnosis of CVD...
2016: Biomedical Engineering Online
https://www.readbyqxmd.com/read/27547548/computational-fluid-dynamics-modelling-of-left-valvular-heart-diseases-during-atrial-fibrillation
#18
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/27544288/comparison-of-the-performance-of-a-sutureless-bioprosthesis-with-two-pericardial-stented-valves-on-small-annuli-an-in%C3%A2-vitro-study
#19
Giordano Tasca, Riccardo Vismara, Andrea Mangini, Claudia Romagnoni, Monica Contino, Alberto Redaelli, Gianfranco Beniamino Fiore, Carlo Antona
BACKGROUND: Aortic valve replacement has evolved recently with the development of the sutureless bioprosthesis. One such valve is the Perceval bioprosthesis, which is built by mounting leaflets of bovine pericardium to a thin stent; this approach has the potential to provide an excellent fluid dynamic performance. We undertook an in vitro study to compare the hydrodynamic performance of the sutureless bioprosthesis with two standard pericardial stented bioprostheses (Crown and Magna)...
August 17, 2016: Annals of Thoracic Surgery
https://www.readbyqxmd.com/read/27529870/assessing-the-performance-of-ultrafast-vector-flow-imaging-in-the-neonatal-heart-via-multiphysics-modeling-and-in-vitro-experiments
#20
Joris Van Cauwenberge, Lasse Lovstakken, Solveig Fadnes, Alfonso Rodriguez-Molares, Jan Vierendeels, Patrick Segers, Abigail Swillens
Ultrafast vector flow imaging would benefit newborn patients with congenital heart disorders, but still requires thorough validation before translation to clinical practice. This study investigates 2D speckle tracking of intraventricular blood flow in neonates when transmitting diverging waves at ultrafast frame rate. Computational and in-vitro studies enabled us to quantify the performance and identify artefacts related to the flow and the imaging sequence. First, synthetic ultrasound images of a neonate's left ventricular flow pattern were obtained with the ultrasound simulator Field II by propagating point scatterers according to 3D intraventricular flow fields obtained with computational fluid dynamics (CFD)...
August 1, 2016: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
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