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Mechanical Valve

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https://www.readbyqxmd.com/read/29352179/growth-and-remodeling-play-opposing-roles-during-postnatal-human-heart-valve-development
#1
Pim J A Oomen, Maria A Holland, Carlijn V C Bouten, Ellen Kuhl, Sandra Loerakker
Tissue growth and remodeling are known to govern mechanical homeostasis in biological tissue, but their relative contributions to homeostasis remain unclear. Here, we use mechanical models, fueled by experimental findings, to demonstrate that growth and remodeling have different effects on heart valve stretch homeostasis during physiological postnatal development. Two developmental stages were considered: early-stage (from infant to adolescent) and late-stage (from adolescent to adult) development. Our models indicated that growth and remodeling play opposing roles in preserving tissue stretch and with time...
January 19, 2018: Scientific Reports
https://www.readbyqxmd.com/read/29352010/genetics-of-syndromic-and-non-syndromic-mitral-valve-prolapse
#2
REVIEW
Thierry Le Tourneau, Jean Mérot, Antoine Rimbert, Solena Le Scouarnec, Vincent Probst, Hervé Le Marec, Robert A Levine, Jean-Jacques Schott
Mitral valve prolapse (MVP) is a common condition that affects 2%-3% of the general population. MVP is thought to include syndromic forms such as Marfan syndrome and non-syndromic MVP, which is the most frequent form. Myxomatous degeneration and fibroelastic deficiency (FED) are regarded as two different forms of non-syndromic MVP. While FED is still considered a degenerative disease associated with ageing, frequent familial clustering has been demonstrated for myxomatous MVP. Familial and genetic studies led to the recognition of reduced penetrance and large phenotypic variability, and to the identification of prodromal or atypical forms as a part of the complex spectrum of the disease...
January 19, 2018: Heart: Official Journal of the British Cardiac Society
https://www.readbyqxmd.com/read/29351596/freedom-solo%C3%A2-versus-trifecta%C3%A2-bioprostheses-clinical-and-haemodynamic-evaluation-after-propensity-score-matching
#3
Rui J Cerqueira, Renata Raimundo, Soraia Moreira, Francisca A Saraiva, Marta Andrade, Elson Salgueiro, Jorge Almeida, Mário Jorge Amorim, Paulo Pinho, André P Lourenço, Adelino Leite-Moreira
OBJECTIVES: The goal of this study was to compare the stentless Freedom Solo® (FS) and the stented Trifecta® (TF) aortic bioprostheses with regard to haemodynamic profile, left ventricular mass regression and early and late postoperative outcomes and survival. METHODS: A longitudinal cohort study of consecutive patients undergoing aortic valve replacement (2009-16) with either the FS or TF at 1 centre was performed. Local databases and national records were queried...
January 16, 2018: European Journal of Cardio-thoracic Surgery
https://www.readbyqxmd.com/read/29350692/control-and-optimisation-of-fluid-flow-in-glaucoma-drainage-device-surgery
#4
Kin Sheng Lim
Avoidance of hypotony in the early post-operative phase following glaucoma drainage device surgery is paramount, if serious complications are to be avoided. Current strategies of preventing early hypotony are either a valve mechanism, as those found in Ahmed Glaucoma Valve or flow restrictor as used in Baerveldt or Molteno implants. The Ahmed glaucoma valve has a pre-tensioned valve which opens and closes at the pre-determined level of intra-ocular pressure. Although the opening and closing pressure can be slightly inconsistent, coinciding with the change of material used in the plate construction, the reliability appears to have improved in recent years...
January 19, 2018: Eye
https://www.readbyqxmd.com/read/29349638/innovation-in-3d-echocardiographic-imaging
#5
REVIEW
Pei-Ni Jone, Nee Khoo
PURPOSE OF REVIEW: The purpose of this review is to detail three-dimensional echocardiographic (3DE) innovations in pre-surgical planning of congenital heart disease, guidance of catheter interventions such as fusion imaging, and functional assessment of patients with congenital heart disease. RECENT FINDINGS: Innovations in 3DE have helped us delineate the details of atrioventricular valve function and understand the mechanism of atrioventricular valve failure in patients with atrioventricular septal defect and single ventricle post repair...
January 19, 2018: Current Treatment Options in Cardiovascular Medicine
https://www.readbyqxmd.com/read/29348423/a-tissue-mimetic-nano-fibrillar-hybrid-injectable-hydrogel-for-potential-soft-tissue-engineering-applications
#6
Neda Latifi, Meisam Asgari, Hojatollah Vali, Luc Mongeau
While collagen type I (Col-I) is commonly used as a structural component of biomaterials, collagen type III (Col-III), another fibril forming collagen ubiquitous in many soft tissues, has not previously been used. In the present study, the novel concept of an injectable hydrogel with semi-interpenetrating polymeric networks of heterotypic collagen fibrils, with tissue-specific Col-III to Col-I ratios, in a glycol-chitosan matrix was investigated. Col-III was introduced as a component of the novel hydrogel, inspired by its co-presence with Col-I in many soft tissues, its influence on the Col-I fibrillogenesis in terms of diameter and mechanics, and its established role in regulating scar formation...
January 18, 2018: Scientific Reports
https://www.readbyqxmd.com/read/29346531/doppler-assessment-of-aortic-stenosis-a-25-operator-study-demonstrating-why-reading-the-peak-velocity-is-superior-to-velocity-time-integral
#7
Stefania Sacchi, Niti M Dhutia, Matthew J Shun-Shin, Massoud Zolgharni, Nilesh Sutaria, Darrel P Francis, Graham D Cole
Aims: Measurements with superior reproducibility are useful clinically and research purposes. Previous reproducibility studies of Doppler assessment of aortic stenosis (AS) have compared only a pair of observers and have not explored the mechanism by which disagreement between operators occurs. Using custom-designed software which stored operators' traces, we investigated the reproducibility of peak and velocity time integral (VTI) measurements across a much larger group of operators and explored the mechanisms by which disagreement arose...
January 15, 2018: European Heart Journal Cardiovascular Imaging
https://www.readbyqxmd.com/read/29340624/early-and-long-term-outcomes-of-mitral-valve-repair-for-barlow-s-disease-a-single-centre-16-year-experience
#8
Anton Tomšic, Yasmine L Hiemstra, Stephanie L van der Pas, Hein Putter, Michel I M Versteegh, Thomas J van Brakel, Nina Ajmone Marsan, Robert J M Klautz, Meindert Palmen
OBJECTIVES: Following mitral valve repair for Barlow's disease, recurrent mitral regurgitation (MR) is believed to occur frequently and is mainly attributed to disease progression. METHODS: Between January 2000 and December 2015, 180 patients (40% women, mean age 58.7 ± 13.5 years) with Barlow's disease underwent mitral valve repair. To provide a longitudinal assessment of mitral valve repair durability, a multistate model for interval-censored observations (4 states: 1, Grade 0/1+ MR; 2, Grade 2+ MR; 3, Grade 3+/4+ MR; 4, reintervention/death) was developed...
January 10, 2018: Interactive Cardiovascular and Thoracic Surgery
https://www.readbyqxmd.com/read/29338299/mitral-valve-replacement-via-a-left-thoracotomy-in-dextrocardia-and-situs-solitus
#9
María García Vieites, María Jose Martinez-Sapiña Llanas, Marcos Gómez Zincke, Beatriz Bouzas Zubeldía, Victor Bautista-Hernandez
Dextrocardia with situs solitus and severe mitral regurgitation is a rare clinical presentation which posse a surgical challenge and requires specific preoperative planning. A 54-year-old women with this anatomy, multiple thoracic procedures, and severe mitral valve regurgitation underwent successful mitral valve replacement with a 27-mm mechanical prosthesis through a left thoracotomy under ventricular fibrillation, on the basis of computed tomography findings. We emphasize the importance of preoperative planning and a surgical approach through a left thoracotomy and under ventricular fibrillation...
January 1, 2018: Asian Cardiovascular & Thoracic Annals
https://www.readbyqxmd.com/read/29334746/-the-current-role-of-warfarin
#10
Jana Michalcová, Alena Buliková, Jiřina Zavřelová, Marie Prudková, Miroslav Penka
Well-managed warfarin therapy remains an important method of anticoagulation in the 21st century, despite the introduction of new antithrombotics into the clinical practice. The main advantages of warfarin are decades of treatment experience, the possibility to monitor its anticoagulant effect using the INR and the last, but not least, the low cost. Currently, approximately 75 % of anticoagulated patients in the Czech Republic are treated with warfarin and warfarin remains the only option for oral anticoagulant therapy in certain clinical conditions (particularly in patients with valvular atrial fibrillation or mechanical heart valves)...
2018: Vnitr̆ní Lékar̆ství
https://www.readbyqxmd.com/read/29328973/feeding-inhibition-in-corbicula-fluminea-o-f-muller-1774-as-an-effect-criterion-to-pollutant-exposure-perspectives-for-ecotoxicity-screening-and-refinement-of-chemical-control
#11
Bruno Branco Castro, Carlos Silva, Inês Patrunilho Efe Macário, Bruno Oliveira, Fernando Gonçalves, Joana Luísa Pereira
Bivalves are commonly used in biomonitoring programs to track pollutants. Several features, including its filter-feeding abilities, cumulatively argue in favour of the use of the Asian clam (Corbicula fluminea) as a biosentinel and an ecotoxicological model. Filtration in bivalves is very sensitive to external stimuli and its control is dictated by regulation of the opening/closure of the valves, which may be used as an avoidance defence against contaminants. Here, we investigate the filter-feeding behaviour of the Asian clam as an endpoint for assessing exposure to pollutants, driven by two complementary goals: (i) to generate relevant and sensitive toxicological information based on the ability of C...
January 4, 2018: Aquatic Toxicology
https://www.readbyqxmd.com/read/29327671/tissue-engineered-heart-valves-a-call-for-mechanistic-studies
#12
Kevin Blum, Joseph Drews, Christopher K Breuer
Heart valve disease carries a substantial risk of morbidity and mortality. Outcomes are significantly improved by valve replacement, but currently-available mechanical and biological replacement valves are associated with complications of their own. Mechanical valves have a high rate of thromboembolism and require lifelong anticoagulation. Biological prosthetic valves have a much shorter lifespan, and are prone to tearing and degradation. Both types of valves lack the capacity for growth, making them particularly problematic in pediatric patients...
January 12, 2018: Tissue Engineering. Part B, Reviews
https://www.readbyqxmd.com/read/29327563/hemodynamic-outcomes-of-the-ross-procedure-versus-other-aortic-valve-replacement-a-systematic-review-and-meta-analysis
#13
Kevin J Um, Graham R McCLURE, Emilie P Belley-Cote, Saurabh Gupta, Ismail Bouhout, Hugo Lortie, Hatim Alraddadi, Ali Alsagheir, Matthias Bossard, William F McINTYRE, Alexandra Lengyel, John W Eikelboom, Maral Ouzounian, Michael W Chu, Dominic Parry, Ismail El-Hamamsy, Richard P Whitlock
INTRODUCTION: Life expectancy in young adults undergoing mechanical or bioprosthetic aortic valve replacement (AVR) may be reduced by up to 20 years compared to age matched controls. The Ross procedure is a durable, anticoagulation-sparing alternative. We performed a systematic review and meta-analysis to compare the valve hemodynamics of the Ross procedure versus other AVR. EVIDENCE ACQUISITION: We searched Cochrane CENTRAL, MEDLINE and EMBASE from inception to February 2017 for randomized controlled trials (RCTs) and observational studies (n≥10 Ross)...
January 9, 2018: Journal of Cardiovascular Surgery
https://www.readbyqxmd.com/read/29326778/-double-ball-valve-mechanism-obstructing-both-right-ventricular-inflow-and-outflow-atypical-presentation-of-right-atrial-myxoma-presenting-as-right-ventricular-mass
#14
Tarun Kumar, Satyam Rajvanshi, Ajay Kumar Sharma, Neeraj Pandit
Large intracavitary masses such as those occupying most of a cardiac chamber and obstructing blood flow are not routinely encountered in clinical practice. The differential diagnosis includes neoplastic as well as nonneoplastic causes. Primary cardiac tumors by themselves are uncommon. We hereby report a rare case of a middle-aged female presenting with New York Heart Association Class III symptoms, whose transthoracic echocardiogram revealed a huge mass in right-sided chambers with a novel double ball valve type movement...
October 2017: Heart Views: the Official Journal of the Gulf Heart Association
https://www.readbyqxmd.com/read/29325903/gata4-loss-of-function-mutation-and-the-congenitally-bicuspid-aortic-valve
#15
Ruo-Gu Li, Ying-Jia Xu, Juan Wang, Xing-Yuan Liu, Fang Yuan, Ri-Tai Huang, Song Xue, Li Li, Hua Liu, Yan-Jie Li, Xin-Kai Qu, Hong-Yu Shi, Min Zhang, Xing-Biao Qiu, Yi-Qing Yang
Aggregating evidence suggests that genetic determinants play a pivotal role in the pathogenesis of the congenitally bicuspid aortic valve (BAV). BAV is of pronounced genetic heterogeneity, and the genetic components underlying BAV in an overwhelming majority of patients remain elusive. In the current study, the whole coding exons and adjacent introns, as well as 5' and 3' untranslated regions of the GATA4 gene, which codes for a zinc-finger transcription factor crucial for the normal development of the aortic valve, were screened by direct sequencing in 150 index patients with congenital BAV...
November 23, 2017: American Journal of Cardiology
https://www.readbyqxmd.com/read/29325642/nhlbi-working-group-recommendations-to-reduce-lipoprotein-a-mediated-risk%C3%A2-of%C3%A2-cardiovascular-disease-and-aortic%C3%A2-stenosis
#16
REVIEW
Sotirios Tsimikas, Sergio Fazio, Keith C Ferdinand, Henry N Ginsberg, Marlys L Koschinsky, Santica M Marcovina, Patrick M Moriarty, Daniel J Rader, Alan T Remaley, Gissette Reyes-Soffer, Raul D Santos, George Thanassoulis, Joseph L Witztum, Simhan Danthi, Michelle Olive, Lijuan Liu
Pathophysiological, epidemiological, and genetic studies provide strong evidence that lipoprotein(a) [Lp(a)] is a causal mediator of cardiovascular disease (CVD) and calcific aortic valve disease (CAVD). Specific therapies to address Lp(a)-mediated CVD and CAVD are in clinical development. Due to knowledge gaps, the National Heart, Lung, and Blood Institute organized a working group that identified challenges in fully understanding the role of Lp(a) in CVD/CAVD. These included the lack of research funding, inadequate experimental models, lack of globally standardized Lp(a) assays, and inadequate understanding of the mechanisms underlying current drug therapies on Lp(a) levels...
January 16, 2018: Journal of the American College of Cardiology
https://www.readbyqxmd.com/read/29321211/pathophysiology-of-degenerative-mitral-regurgitation-new-3-dimensional-imaging-insights
#17
Clemence Antoine, Francesca Mantovani, Giovanni Benfari, Sunil V Mankad, Joseph F Maalouf, Hector I Michelena, Maurice Enriquez-Sarano
Despite its high prevalence, little is known about mechanisms of mitral regurgitation in degenerative mitral valve disease apart from the leaflet prolapse itself. Mitral valve is a complex structure, including mitral annulus, mitral leaflets, papillary muscles, chords, and left ventricular walls. All these structures are involved in physiological and pathological functioning of this valvuloventricular complex but up to now were difficult to analyze because of inherent limitations of 2-dimensional imaging. The advent of 3-dimensional echocardiography, computed tomography, and cardiac magnetic resonance imaging overcoming these limitations provides new insights into mechanistic analysis of degenerative mitral regurgitation...
January 2018: Circulation. Cardiovascular Imaging
https://www.readbyqxmd.com/read/29321130/exercise-hemodynamic-and-functional-capacity-after-mitral-valve-replacement-in-patients-with-ischemic-mitral-regurgitation-a-comparison-of-mechanical-versus-biological-prostheses
#18
Carlo Fino, Attilio Iacovoni, Philippe Pibarot, John R Pepper, Paolo Ferrero, Maurizio Merlo, Lorenzo Galletti, Massimo Caputo, Paolo Ferrazzi, Constantinos Anagnostopoulos, Diego Cugola, Michele Senni, Diego Bellavia, Julien Magne
BACKGROUND: In patients with ischemic mitral regurgitation requiring mitral valve replacement (MVR), the choice of the prosthesis type is crucial. The exercise hemodynamic and functional capacity performance in patients with contemporary prostheses have never been investigated. To compare exercise hemodynamic and functional capacity between biological (MVRb) and mechanical (MVRm) prostheses. METHODS AND RESULTS: We analyzed 86 consecutive patients with ischemic mitral regurgitation who underwent MVRb (n=41) or MVRm (n=45) and coronary artery bypass grafting...
January 2018: Circulation. Heart Failure
https://www.readbyqxmd.com/read/29317805/compression-of-the-right-coronary-artery-by-an-aortic-pseudoaneurysm-after-infective-endocarditis-an-unusual-case-of-myocardial-ischemia
#19
Juan Lacalzada-Almeida, Alejandro De la Rosa-Hernández, María Manuela Izquierdo-Gómez, Javier García-Niebla, Iván Hernández-Betancor, Juan Alfonso Bonilla-Arjona, Antonio Barragán-Acea, Ignacio Laynez-Cerdeña
A 61-year-old male with a prosthetic St Jude aortic valve size 24 presented with heart failure symptoms and minimal-effort angina. Eleven months earlier, the patient had undergone cardiac surgery because of an aortic root dilatation and bicuspid aortic valve with severe regurgitation secondary to infectious endocarditis by Coxiela burnetii and coronary artery disease in the left circumflex coronary artery. Then, a prosthesis valve and a saphenous bypass graft to the left circumflex coronary artery were placed...
2018: Clinical Interventions in Aging
https://www.readbyqxmd.com/read/29316662/recurrent-hemorrhagic-conversion-of-ischemic-stroke-in-a-patient-with-mechanical-heart-valve-a-case-report-and-literature-review
#20
Micheal Jace Tarver, Tyler Schmidt, Michael T Koltz
The authors present a unique case of recurrent stroke, discovered to be secondary to hemorrhagic conversion of microemboli from a mechanical aortic valve despite anticoagulation with Coumadin. The complexity of this case was magnified by the patient's young age, a mechanical heart valve (MHV), and a need for anticoagulation to maintain MHV patency in a setting of potentially life-threatening intracranial hemorrhage. Anticoagulant and antiplatelet therapy are risk factors for hemorrhagic conversion post-cerebral ischemia; however, the pathophysiology underlying endothelial cell dysfunction causing red blood cell extravasation is an active area of basic and clinical research...
January 7, 2018: Brain Sciences
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