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intraventricular vortex

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https://www.readbyqxmd.com/read/28445281/relationship-between-the-abnormal-diastolic-vortex-structure-and-impaired-left-ventricle-filling-in-patients-with-hyperthyroidism
#1
Bin-Yu Zhou, Ming-Xing Xie, Jing Wang, Xin-Fang Wang, Qing Lv, Man-Wei Liu, Shuang-Shuang Kong, Ping-Yu Zhang, Jin-Feng Liu
Intraventricular hydrodynamics plays an important role in evaluating cardiac function. Relationship between diastolic vortex and left ventricular (LV) filling is still rarely elucidated. The aim of this study was to evaluate the evolution of vortex during diastole in hyperthyroidism (HT) and explore the alteration of hydromechanics characteristics with sensitive indexes.Forty-three patients diagnosed with HT were classified into 2 groups according to whether myocardial damage existed: simple hyperthyroid group (HT1, n = 21) and thyrotoxic cardiomyopathy (HT2, n = 22)...
April 2017: Medicine (Baltimore)
https://www.readbyqxmd.com/read/28389690/energy-dynamics-of-the-intraventricular-vortex-after-mitral-valve-surgery
#2
Kouki Nakashima, Keiichi Itatani, Tadashi Kitamura, Norihiko Oka, Tetsuya Horai, Shohei Miyazaki, Masaki Nie, Kagami Miyaji
Mitral valve morphology after mitral valve surgery affects postoperative intraventricular flow patterns and long-term cardiac performance. We visualized ventricular flow by echocardiography vector flow mapping (VFM) to reveal the impact of different mitral valve procedures. Eleven cases of mechanical mitral valve replacement (nine in the anti-anatomical and two in the anatomical position), three bioprosthetic mitral valve replacements, and four mitral valve repairs were evaluated. The mean age at the procedure was 57...
April 7, 2017: Heart and Vessels
https://www.readbyqxmd.com/read/28343891/an-investigation-on-the-effects-of-the-angles-between-the-mitral-and-aortic-orifice-during-diastolic-period-using-fsi
#3
Md Shamsul Arefin
BACKGROUND: It was well documented that the changes in the physiological structure of the heart can alter the hemodynamic behaviour of the human left ventricle. Although there were various imaging tools that can stipulate the blood flow characteristics inside the ventricle, but the effect of the variation in the angles between the mitral and aortic orifices were yet to be determined. Hence the primary focus of this paper was to use Fluid-Structure Interaction scheme throughout the diastolic phase to examine and determine the hemodynamic behaviour inside the cavity under various angles between the mitral and aortic orifices (50°, 55° and 60°)...
March 18, 2017: Pathophysiology: the Official Journal of the International Society for Pathophysiology
https://www.readbyqxmd.com/read/28332315/significant-increase-of-flow-kinetic-energy-in-nonresponders-patients-to-cardiac-resynchronization-therapy
#4
Sara Cimino, Dino Palombizio, Francesco Cicogna, Donatella Cantisani, Manuela Reali, Domenico Filomena, Valentina Petronilli, Carlo Iacoboni, Luciano Agati
BACKGROUNDS: It's still unclear if different patterns of intraventricular flow dynamics may be detected in patients nonresponders to cardiac resynchronization therapy (CRT) as compared to responders ones. Aim of this study was to evaluate the characteristics of left ventricular (LV) flow dynamics 6-months after CRT to identify Echo-particle imaging velocity (PIV) patterns were more frequently detected in nonresponders patients. METHODS: Thirty-two patients with dilated cardiomyopathy, undergoing CRT, were enrolled in this study...
March 23, 2017: Echocardiography
https://www.readbyqxmd.com/read/28329295/flow-dynamics-assessment-of-mitral-valve-surgery-by-intraoperative-vector-flow-mapping
#5
Koichi Akiyama, Naotoshi Nakamura, Keiichi Itatani, Yoshifumi Naito, Mao Kinoshita, Masaru Shimizu, Saeko Hamaoka, Hideya Kato, Hiroaki Yasumoto, Yasufumi Nakajima, Toshiki Mizobe, Satoshi Numata, Hitoshi Yaku, Teiji Sawa
OBJECTIVES: We assessed vortex patterns and energy loss in left ventricular flow in patients who underwent mitral valve repair or replacement with bioprosthetic valves. METHODS: Vector flow mapping was performed before and after the procedure in 15 and 17 patients who underwent repair and replacement, respectively. The preprocedure mitral-septal angle was measured in all patients. Relationships between vortex patterns or energy loss change (ELC) and annuloplasty ring or bioprosthetic valve sizes or the effect of mitral leaflet resection in the repair group were statistically analysed...
June 1, 2017: Interactive Cardiovascular and Thoracic Surgery
https://www.readbyqxmd.com/read/28328554/the-effect-of-inlet-cannula-length-on-the-intraventricular-flow-field-an-in-vitro-flow-visualization-study-using-the-evaheart-lvad
#6
Karen May-Newman, Juyeun Moon, Varsha Ramesh, Ricardo Montes, Josue Campos, Brian Herold, Paul Isingoma, Tadashi Motomura, Robert Benkowski
LVAD inflow cannula malposition is a significant risk for pump thrombosis. Thrombus development is influenced by altered flow dynamics, such as stasis or high shear that promote coagulation. The goal of this study was to measure the intraventricular flow field surrounding the apical inflow cannula of the Evaheart centrifugal LVAD, and assess flow stasis, vortex structures and pulsatility for a range of cannula insertion depths and support conditions. Experimental studies were performed using a mock loop with a customized silicone left ventricle (LV) and the Evaheart LVAD...
March 20, 2017: ASAIO Journal: a Peer-reviewed Journal of the American Society for Artificial Internal Organs
https://www.readbyqxmd.com/read/27913338/intracardiac-vortex-dynamics-by-high-frame-rate-doppler-vortography-in-vivo-comparison-with-vector-flow-mapping-and-4-d-flow-mri
#7
Julia Faurie, Mathilde Baudet, Kondo Claude Assi, Dominique Auger, Guillaume Gilbert, Francois Tournoux, Damien Garcia
Recent studies have suggested that intracardiac vortex flow imaging could be of clinical interest to early diagnose the diastolic heart function. Doppler vortography has been introduced as a simple color Doppler method to detect and quantify intraventricular vortices. This method is able to locate a vortex core based on the recognition of an antisymmetric pattern in the Doppler velocity field. Because the heart is a fast-moving organ, high frame rates are needed to decipher the whole blood vortex dynamics during diastole...
February 2017: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
https://www.readbyqxmd.com/read/27866678/patient-specific-cfd-models-for-intraventricular-flow-analysis-from-3d-ultrasound-imaging-comparison-of-three-clinical-cases
#8
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/27796137/two-dimensional-intraventricular-flow-pattern-visualization-using-the-image-based-computational-fluid-dynamics
#9
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/27663769/fluid-mechanics-of-human-fetal-right-ventricles-from-image-based-computational-fluid-dynamics-using-4d-clinical-ultrasound-scans
#10
Hadi Wiputra, Chang Quan Lai, Guat Ling Lim, Joel Jia Wei Heng, Lan Guo, Sanah Merchant Soomar, Hwa Liang Leo, Arijit Biwas, Citra Nurfarah Zaini Mattar, Choon Hwai Yap
There are 0.6-1.9% of US children who were born with congenital heart malformations. Clinical and animal studies suggest 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 four-dimensional ultrasound scans of three 20-wk-old normal human fetuses, to characterize their flow and energy dynamics. Peak intraventricular pressure gradients were found to be 0...
December 1, 2016: American Journal of Physiology. Heart and Circulatory Physiology
https://www.readbyqxmd.com/read/27612951/patient-specific-cfd-simulation-of-intraventricular-haemodynamics-based-on-3d-ultrasound-imaging
#11
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/26993615/cardiac-mri-based-numerical-modeling-of-left-ventricular-fluid-dynamics-with-mitral-valve-incorporated
#12
Boyang Su, Ru San Tan, Ju Le Tan, Kenneth Wei Qiang Guo, Jun Mei Zhang, Shuang Leng, Xiaodan Zhao, John Carson Allen, Liang Zhong
Recent numerical studies were focused on the modeling of flow in patient-specific left ventricle (LV); however, the mitral valve (MV) was usually excluded. In this study, both patient-specific LV and MV were modeled to achieve a more realistic intraventricular flow. Cardiac MRI images were acquired from a pulmonary arterial hypertension (PAH) patient and a healthy volunteer, and manual segmentation was conducted to reconstruct three-dimensional (3D) LV and MV geometries at each frame. Based on these 3D geometries, vortex formation time (VFT) was derived, and the values were 4...
May 3, 2016: Journal of Biomechanics
https://www.readbyqxmd.com/read/26833579/intraventricular-isovolumic-relaxation-flow-patterns-studied-by-using-vector-flow-mapping
#13
Haibin Zhang, Xiaofeng Ren, Jin Song, Xinyu Cao, Benna Wang, Ying Liu, Zhiguo Li, Na Ma
AIMS: The purpose of this study was to characterize isovolumic relaxation flow (IRF) in the left ventricle (LV) in patients with a wide spectrum of LV dysfunction. METHODS: Color Doppler flow imaging was performed in 61 patients with coronary artery disease, 29 patients with dilated cardiomyopathy, and 41 healthy controls. Vector flow mapping was used to analyze the Doppler data. RESULTS: IRF patterns were divided into three types: pattern A, an apically directed flow; pattern B, a bidirectional flow with small scattered vortices; and pattern C, a large vortex persisting throughout the entire isovolumic relaxation (IVR) period...
June 2016: Echocardiography
https://www.readbyqxmd.com/read/26577230/asymptotic-model-of-fluid-tissue-interaction-for-mitral-valve-dynamics
#14
Federico Domenichini, Gianni Pedrizzetti
The vortex formation process inside the left ventricle is intrinsically connected to the dynamics of the mitral leaflets while they interact with the flow crossing the valve during diastole. The description of the dynamics of a natural mitral valve still represents a challenging issue, especially because its material properties are not measurable in vivo. Medical imaging can provide some indications about the geometry of the valve, but not about its mechanical properties. In this work, we introduce a parametric model of the mitral valve geometry, whose motion is described in the asymptotic limit under the assumption that it moves with the flow, without any additional resistance other than that given by its shape, and without the need to specify its material properties...
June 2015: Cardiovascular Engineering and Technology
https://www.readbyqxmd.com/read/26223930/left-ventricular-systolic-intraventricular-flow-field-assessment-in-hyperthyroidism-patients-using-vector-flow-mapping
#15
Bin-Yu Zhou, Jing Wang, Ming-Xing Xie, Man-Wei Liu, Qing Lv
Intraventricular hydrodynamics is considered an important component of cardiac function assessment. Vector flow mapping (VFM) is a novel flow visualization method to describe cardiac pathophysiological condition. This study examined use of new VFM and flow field for assessment of left ventricular (LV) systolic hemodynamics in patients with simple hyperthyroidism (HT). Thirty-seven simple HT patients were enrolled as HT group, and 38 gender- and age-matched healthy volunteers as control group. VFM model was used to analyze LV flow field at LV apical long-axis view...
August 2015: Journal of Huazhong University of Science and Technology. Medical Sciences
https://www.readbyqxmd.com/read/25971844/mechanotransduction-mechanisms-for-intraventricular-diastolic-vortex-forces-and-myocardial-deformations-part-2
#16
Ares Pasipoularides
Epigenetic mechanisms are fundamental in cardiac adaptations, remodeling, reverse remodeling, and disease. A primary goal of translational cardiovascular research is recognizing whether disease-related changes in phenotype can be averted by eliminating or reducing the effects of environmental epigenetic risks. There may be significant medical benefits in using gene-by-environment interaction knowledge to prevent or reverse organ abnormalities and disease. This survey proposes that "environmental" forces associated with diastolic RV/LV rotatory flows exert important, albeit still unappreciated, epigenetic actions influencing functional and morphological cardiac adaptations...
July 2015: Journal of Cardiovascular Translational Research
https://www.readbyqxmd.com/read/25961285/numerical-modeling-of-intraventricular-flow-during-diastole-after-implantation-of-bmhv
#17
Boyang Su, Foad Kabinejadian, Hui Qun Phang, Gideon Praveen Kumar, Fangsen Cui, Sangho Kim, Ru San Tan, Jimmy Kim Fatt Hon, John Carson Allen, Hwa Liang Leo, Liang Zhong
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...
2015: PloS One
https://www.readbyqxmd.com/read/25624114/mechanotransduction-mechanisms-for-intraventricular-diastolic-vortex-forces-and-myocardial-deformations-part-1
#18
REVIEW
Ares Pasipoularides
Epigenetic mechanisms are fundamental in cardiac adaptations, remodeling, reverse remodeling, and disease. This two-article series proposes that variable forces associated with diastolic RV/LV rotatory intraventricular flows can exert physiologically and clinically important, albeit still unappreciated, epigenetic actions influencing functional and morphological cardiac adaptations and/or maladaptations. Taken in toto, the two-part survey formulates a new paradigm in which intraventricular diastolic filling vortex-associated forces play a fundamental epigenetic role, and examines how heart cells react to these forces...
February 2015: Journal of Cardiovascular Translational Research
https://www.readbyqxmd.com/read/25609509/vortex-formation-time-is-not-an-index-of-ventricular-function
#19
REVIEW
Ares Pasipoularides, Pavlos P Vlachos, William C Little
The diastolic intraventricular ring vortex formation and pinch-off process may provide clinically useful insights into diastolic function in health and disease. The vortex ring formation time (FT) concept, based on hydrodynamic experiments dealing with unconfined (large tank) flow, has attracted considerable attention and popularity. Dynamic conditions evolving within the very confined space of a filling, expansible ventricular chamber with relaxing and rebounding, and viscoelastic muscular boundaries diverge from unconfined (large tank) flow and encompass rebounding walls' suction and myocardial relaxation...
February 2015: Journal of Cardiovascular Translational Research
https://www.readbyqxmd.com/read/25529139/cardiac-fluid-dynamics-anticipates-heart-adaptation
#20
Gianni Pedrizzetti, Alfonso R Martiniello, Valter Bianchi, Antonio D'Onofrio, Pio Caso, Giovanni Tonti
Hemodynamic forces represent an epigenetic factor during heart development and are supposed to influence the pathology of the grown heart. Cardiac blood motion is characterized by a vortical dynamics, and it is common belief that the cardiac vortex has a role in disease progressions or regression. Here we provide a preliminary demonstration about the relevance of maladaptive intra-cardiac vortex dynamics in the geometrical adaptation of the dysfunctional heart. We employed an in vivo model of patients who present a stable normal heart function in virtue of the cardiac resynchronization therapy (CRT, bi-ventricular pace-maker) and who are expected to develop left ventricle remodeling if pace-maker was switched off...
January 21, 2015: Journal of Biomechanics
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