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Elastic properties of mitral valve

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https://www.readbyqxmd.com/read/29232300/three-dimensional-printing-of-life-like-models-for-simulation-and-training-of-minimally-invasive-cardiac-surgery
#1
Toshiyuki Yamada, Motohiko Osako, Tomoya Uchimuro, Ryogen Yoon, Toshiaki Morikawa, Maki Sugimoto, Hisao Suda, Hideyuki Shimizu
OBJECTIVE: As the use of minimally invasive surgery in cardiothoracic surgery increases, so does the need for simulation and training. We developed a heart model for simulation and training of minimally invasive cardiac surgery, particularly minimally invasive mitral valve repair using our new three-dimensional printing system. METHODS: Digital imaging and communication in medicine data from patient computed tomography, three-dimensional computer-aided design, and three-dimensional printing helped create replicas of the heart and thoracic cavity...
December 7, 2017: Innovations: Technology and Techniques in Cardiothoracic and Vascular Surgery
https://www.readbyqxmd.com/read/28822668/intrinsic-wave-propagation-of-myocardial-stretch-a-new-tool-to-evaluate-myocardial-stiffness-a-pilot-study-in-patients-with-aortic-stenosis-and-mitral-regurgitation
#2
Cristina Pislaru, Mahmoud M Alashry, Jeremy J Thaden, Patricia A Pellikka, Maurice Enriquez-Sarano, Sorin V Pislaru
BACKGROUND: Left ventricular (LV) filling following atrial contraction generates LV myocardial stretch that propagates from base to apex with a speed proportional to myocardial elasticity. The aim of this study was to test the hypothesis that intrinsic velocity propagation of myocardial stretch (iVP) would be altered in patients with valvular disease and chronic LV pressure overload or volume overload, which may adversely affect mechanical properties of the LV tissue. A second aim was to compare iVP with flow propagation velocity in the chamber...
November 2017: Journal of the American Society of Echocardiography
https://www.readbyqxmd.com/read/28544833/how-heart-valves-evolve-to-adapt-to-an-extreme-pressure-system-morphologic-and-biomechanical-properties-of-giraffe-heart-valves
#3
Jonas Amstrup Funder, Carl Christian Danielsen, Ulrik Baandrup, Bo Martin Bibby, Ted Carl Andelius, Emil Toft Brøndum, Tobias Wang, J Michael Hasenkam
BACKGROUND: Heart valves which exist naturally in an extreme-pressure system must have evolved in a way to resist the stresses of high pressure. Giraffes are interesting as they naturally have a blood pressure twice that of humans. Thus, knowledge regarding giraffe heart valves may aid in developing techniques to design improved pressure-resistant biological heart valves. METHODS: Heart valves from 12 giraffes and 10 calves were explanted and subjected to either biomechanical or morphological examinations...
January 2017: Journal of Heart Valve Disease
https://www.readbyqxmd.com/read/27495965/surgical-repair-of-mitral-valve-disease-in-children-perioperative-changes-in-respiratory-function
#4
Iliona Malaspinas, Ferenc Petak, Lionel Chok, Anne Perrin, Anne-Laure Martin, Maurice Beghetti, Walid Habre
OBJECTIVE: To assess the profile of changes in airway and respiratory tissue mechanics within a follow-up study performed in children with mitral valve disease, before and after surgical valve repair. DESIGN: Perioperative measurements in a prospective, consecutive cross-sectional study. SETTING: University hospital, tertiary care teaching hospital PARTICIPANTS: The study comprised 24 children with congenital or post-rheumatic mitral valve insufficiency...
October 2016: Journal of Cardiothoracic and Vascular Anesthesia
https://www.readbyqxmd.com/read/27315372/characterization-of-biomechanical-properties-of-aged-human-and-ovine-mitral-valve-chordae-tendineae
#5
Keping Zuo, Thuy Pham, Kewei Li, Caitlin Martin, Zhaoming He, Wei Sun
The mitral valve (MV) is a highly complex cardiac valve consisting of an annulus, anterior and posterior leaflets, chordae tendineae (chords) and two papillary muscles. The chordae tendineae mechanics play a pivotal role in proper MV function: the chords help maintain proper leaflet coaptation and rupture of the chordae tendineae due to disease or aging can lead to mitral valve insufficiency. Therefore, the aim of this study was to characterize the mechanical properties of aged human and ovine mitral chordae tendineae...
September 2016: Journal of the Mechanical Behavior of Biomedical Materials
https://www.readbyqxmd.com/read/26708255/tissue-engineered-mitral-valve-chordae-tendineae-biomechanical-and-biological-characterization-of-decellularized-porcine-chordae
#6
Wenhui Gong, Sen Li, Dong Lei, Peng Huang, Zhize Yuan, Zhengwei You, Xiaofeng Ye, Qiang Zhao
Chordae tendineae are essential for maintaining mitral valve function. Chordae replacement is one of the valve repair procedures commonly used to treat mitral valve regurgitation. But current chordae alternatives (polytetrafluoroethylene, ePTFE) do not have the elastic and self-regenerative properties. Moreover, the ePTFE sutures sometimes fail due to degeneration, calcification and rupture. Tissue-engineered chordae tendineae may overcome these problems. The utility of xenogeneic chordae for tissue-engineered chordae tendineae has not yet been adequately explored...
March 2016: Journal of the Mechanical Behavior of Biomedical Materials
https://www.readbyqxmd.com/read/26257247/echocardiographic-evaluation-in-subjects-with-%C3%AE-1-antitrypsin-deficiency
#7
Enrico Vizzardi, Luciano Corda, Edoardo Sciatti, Elisa Roca, Stefania Redolfi, Marianna Arici, Laura Pini, Ivano Bonadei, Marco Metra, Claudio Tantucci
BACKGROUND: α1-Antitrypsin (AAT) deficiency (AATD) is a genetic condition associated with early-onset panacinar emphysema and, less often, vascular disease. Recently, abnormal elastic properties of ascending aortic wall were described in ZZ genotype AATD subjects who incidentally showed an increased left ventricular mass. MATERIALS AND METHODS: To evaluate biventricular dimensions, valvular apparatus, systolic and diastolic function, 33 AATD subjects with ZZ genotype and 33 healthy subjects matched for age and sex underwent a complete echocardiographic assessment...
September 2015: European Journal of Clinical Investigation
https://www.readbyqxmd.com/read/25345485/the-effects-of-successful-percutaneous-mitral-balloon-valvuloplasty-on-acute-and-intermediate-term-aortic-stiffness
#8
Sinan Inci, Gökay Nar, Mustafa Kemal Erol, Selami Demirelli, Hakan Duman, Serkan Serdar, Fatih Erol
AIM: The aim of this study was to evaluate the effects of percutaneous mitral balloon valvuloplasty (PMBV) on short- and intermediate-term aortic stiffness in patients with mitral stenosis. MATERIALS AND METHODS: This prospective study included 56 patients with critical mitral stenosis in normal sinus rhythm (68% female; mean age: 42 ± 11 years) and 37 healthy controls. Aortic stiffness was measured using transthoracic echocardiography before PMBV, and 24-48 hours and 1 year post procedure...
May 2015: Echocardiography
https://www.readbyqxmd.com/read/24224419/impact-of-rheumatic-mitral-stenosis-on-aortic-elastic-properties
#9
Suleyman Ercan, Gokhan Altunbas, Vedat Davutoglu, Fethi Yavuz, Okkeş Uku, Fuat Basanalan, Mehmet Kaplan, Hayri Alici
BACKGROUND AND AIM OF THE STUDY: Although mitral stenosis has profound effects on the circulation and hemodynamics, few data exist regarding its impact on aortic elastic properties. The study aim was to determine the association between mitral stenosis and aortic elastic properties by using strain and distensibility as a surrogate. METHODS: Sixty-six patients with echocardiographic documentation of rheumatic mitral stenosis, and 25 age- and gender-matched healthy control subjects were enrolled in the study...
July 2013: Journal of Heart Valve Disease
https://www.readbyqxmd.com/read/24039052/material-properties-of-aged-human-mitral-valve-leaflets
#10
Thuy Pham, Wei Sun
This study aimed to characterize the mechanical properties of aged human anterior mitral leaflets (AML) and posterior mitral leaflets (PML). The AML and PML samples from explanted human hearts (n = 21, mean age of 82.62 ± 8.77-years-old) were subjected to planar biaxial mechanical tests. The material stiffness, extensibility, and degree of anisotropy of the leaflet samples were quantified. The microstructure of the samples was assessed through histology. Both the AML and PML samples exhibited a nonlinear and anisotropic behavior with the circumferential direction being stiffer than the radial direction...
August 2014: Journal of Biomedical Materials Research. Part A
https://www.readbyqxmd.com/read/23846436/mitral-valve-closure-prediction-with-3-d-personalized-anatomical-models-and-anisotropic-hyperelastic-tissue-assumptions
#11
C Sprouse, R Mukherjee, P Burlina
This study is concerned with the development of patient-specific simulations of the mitral valve that use personalized anatomical models derived from 3-D transesophageal echocardiography (3-D TEE). The proposed method predicts the closed configuration of the mitral valve by solving for an equilibrium solution that balances various forces including blood pressure, tissue collision, valve tethering, and tissue elasticity. The model also incorporates realistic hyperelastic and anisotropic properties for the valve leaflets...
November 2013: IEEE Transactions on Bio-medical Engineering
https://www.readbyqxmd.com/read/23713987/why-aortic-elasticity-differs-among-classical-and-non-classical-mitral-valve-prolapsed
#12
Murat Unlu, Sait Demirkol, Mustafa Aparci, Zekeriya Arslan, Sevket Balta, Umuttan Dogan, Baris Kilicarslan, Ozcan Ozeke, Turgay Celik, Atila Iyisoy
BACKGROUND: Mitral valve prolapse (MVP) is the most common valvular heart disease and characterized by the displacement of an abnormally thickened mitral valve leaflet into the left atrium during systole. There are two types of MVP, broadly classified as classic (thickness ≥5 mm) and non-classic (thickness <5 mm) according to the morphology of the leaflets. We aimed to investigate elastic properties of the aorta in young male patients with classical and non-classical MVP. MATERIAL/METHODS: In the present study, 63 young adult males (mean age: 22...
2014: Clinical and Experimental Hypertension: CHE
https://www.readbyqxmd.com/read/23168222/effect-of-biodegradation-and-de-novo-matrix-synthesis-on-the-mechanical-properties-of-valvular-interstitial-cell-seeded-polyglycerol-sebacate-polycaprolactone-scaffolds
#13
Shilpa Sant, Dharini Iyer, Akhilesh K Gaharwar, Alpesh Patel, Ali Khademhosseini
The development of living heart valves that grow with the patient is a promising strategy for heart valve replacements in pediatric patients. Despite active research in the field of tissue engineered heart valves there have been limited efforts to optimize the balance between biodegradation of the scaffolds and de novo extracellular matrix (ECM) synthesis by cells and study their consequences on the mechanical properties of the cell-seeded construct. This study investigates the effect of in vitro degradation and ECM secretion on the mechanical properties of hybrid polyester scaffolds...
April 2013: Acta Biomaterialia
https://www.readbyqxmd.com/read/22735910/autonomic-regulation-of-mechanical-properties-in-porcine-mitral-valve-cusps
#14
Xiang Hu, Qiang Zhao, Xiaofeng Ye
BACKGROUND: The presence of nerves in heart valves was first depicted decades ago and identified into subpopulations: sympathetic, parasympathetic. So valves are expected to be greatly affected by the autonomic nerves. However, few studies have focused on the regulation of heart valves by the autonomic nervous system. OBJECTIVE: We sought to identify the role of the autonomic nervous system in the regulation of the mechanical properties of porcine mitral valve tissues...
April 2012: Arquivos Brasileiros de Cardiologia
https://www.readbyqxmd.com/read/22542273/evaluation-of-right-ventricular-systolic-function-after-mitral-valve-repair-a-two-dimensional-doppler-speckle-tracking-and-three-dimensional-echocardiographic-study
#15
RANDOMIZED CONTROLLED TRIAL
Francesco Maffessanti, Paola Gripari, Gloria Tamborini, Manuela Muratori, Laura Fusini, Francesco Alamanni, Marco Zanobini, Cesare Fiorentini, Enrico G Caiani, Mauro Pepi
BACKGROUND: Conventional indices of right ventricular (RV) function are known to be reduced after cardiac surgery, as a consequence of geometric rather than functional alterations. New techniques, such as three-dimensional (3D) transthoracic and two-dimensional speckle-tracking echocardiography, may be useful in postsurgical RV assessment. The aim of this study was to compare indices of RV function obtained using different echocardiographic modalities, before and after surgery. METHODS: Forty-two patients were screened the day before and 6 months after mitral valve repair...
July 2012: Journal of the American Society of Echocardiography
https://www.readbyqxmd.com/read/22301170/comparison-of-biaxial-mechanical-properties-of-coronary-sinus-tissues-from-porcine-ovine-and-aged-human-species
#16
COMPARATIVE STUDY
Thuy Pham, Wei Sun
Due to its proximity to the mitral valve, the coronary sinus (CS) vessel serves as a conduit for the deployment and implantation of the percutaneous transvenous mitral annuloplasty (PTMA) devices that can potentially reduce the mitral regurgitation. Because CS vessel is a venous tissue and seldom diseased, its mechanical properties have not been well studied. In this study, we performed a multi-axial mechanical test and histological analysis to characterize the mechanical and structural properties of the aged human, porcine and ovine CS tissues...
February 2012: Journal of the Mechanical Behavior of Biomedical Materials
https://www.readbyqxmd.com/read/21546155/imaging-of-wall-motion-coupled-with-blood-flow-velocity-in-the-heart-and-vessels-in-vivo-a-feasibility-study
#17
Jianwen Luo, Elisa E Konofagou
The mechanical property and geometry changes as a result of cardiovascular disease affect both the wall motion and blood flow in the heart and vessels, whereas the latter two are also coupled and therefore continuously influence one another. Simultaneous and registered imaging of both cardiovascular wall motion and blood velocity may thus contribute to more complete computational models of cardiovascular mechanical and fluid dynamics as well as provide additional diagnostic information. The objective of this paper was to determine the feasibility of imaging cardiovascular wall motion coupled with blood flow in vivo...
June 2011: Ultrasound in Medicine & Biology
https://www.readbyqxmd.com/read/21529726/elastic-properties-of-aortic-wall-in-patients-with-bicuspid-aortic-valve-by-magnetic-resonance-imaging
#18
COMPARATIVE STUDY
Giovanni Donato Aquaro, Lamia Ait-Ali, Maira Levorato Basso, Massimo Lombardi, Alessandro Pingitore, Pierluigi Festa
Bicuspid aortic valve (BAV) is frequently associated with aortic wall abnormalities, including dilation of the ascending aorta and even dissection. We propose 2 new indexes of aortic wall biophysical properties, the maximum rates of systolic distension and diastolic recoil (MRSD and MRDR, respectively), in patients with BAV and matched control subjects. We evaluated 53 consecutive young patients with BAV (36 males, mean age 16 ± 4 years) with mild aortic valve disease and a control group of 22 age- and gender-matched healthy volunteers...
July 1, 2011: American Journal of Cardiology
https://www.readbyqxmd.com/read/21315467/aortic-and-left-ventricular-remodeling-in-patients-with-bicuspid-aortic-valve-without-significant-valvular-dysfunction-a-prospective-study
#19
RANDOMIZED CONTROLLED TRIAL
Giuseppe Santarpia, Giancarlo Scognamiglio, Giovanni Di Salvo, Michele D'Alto, Berardo Sarubbi, Emanuele Romeo, Ciro Indolfi, Maurizio Cotrufo, Raffaele Calabrò
BACKGROUND: Bicuspid aortic valve (BAV) represents the most common cardiac congenital malformation in the adult age. It is frequently associated with dilatation, aneurysm and dissection of the ascending aorta. The purpose of the following study was to evaluate in patients with BAV: 1) the elastic properties of the ascending aorta, 2) the mechanical function of the left ventricle and 3) stiffness, elasticity and strain of the epi-aortic vessels wall. METHODS: Forty BAV patients (28M/12F; age 20...
July 26, 2012: International Journal of Cardiology
https://www.readbyqxmd.com/read/21214101/functional-characterization-of-fibronectin-separated-valve-interstitial-cell-subpopulations-in-three-dimensional-culture
#20
Elizabeth H Stephens, Joshua L Carroll, Allison D Post, Joyce J Kuo, K Jane Grande-Allen
BACKGROUND AND AIM OF THE STUDY: Myxomatous mitral valves (MVs) contain elevated proportions of myofibroblasts, a valve interstitial cell (VIC) subpopulation that may be important in disease pathogenesis. A novel technique was recently developed for the isolation of VIC myofibroblasts using time-dependent adhesion to fibronectin (FN). Cells that adhere rapidly to FN ('FAST') demonstrate myofibroblast cell phenotype markers, in contrast to cells that fail to adhere after a longer time ('SLOW')...
November 2010: Journal of Heart Valve Disease
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