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Sample records for bi-leaflet heart valve

  1. Laser Doppler anemometry measurements of steady flow through two bi-leaflet prosthetic heart valves

    Directory of Open Access Journals (Sweden)

    Ovandir Bazan

    2013-12-01

    Full Text Available INTRODUCTION: In vitro hydrodynamic characterization of prosthetic heart valves provides important information regarding their operation, especially if performed by noninvasive techniques of anemometry. Once velocity profiles for each valve are provided, it is possible to compare them in terms of hydrodynamic performance. In this first experimental study using laser doppler anemometry with mechanical valves, the simulations were performed at a steady flow workbench. OBJECTIVE: To compare unidimensional velocity profiles at the central plane of two bi-leaflet aortic prosthesis from St. Jude (AGN 21 - 751 and 21 AJ - 501 models exposed to a steady flow regime, on four distinct sections, three downstream and one upstream. METHODS: To provide similar conditions for the flow through each prosthesis by a steady flow workbench (water, flow rate of 17L/min. and, for the same sections and sweeps, to obtain the velocity profiles of each heart valve by unidimensional measurements. RESULTS: It was found that higher velocities correspond to the prosthesis with smaller inner diameter and instabilities of flow are larger as the section of interest is closer to the valve. Regions of recirculation, stagnation of flow, low pressure, and flow peak velocities were also found. CONCLUSIONS: Considering the hydrodynamic aspect and for every section measured, it could be concluded that the prosthesis model AGN 21 - 751 (RegentTM is superior to the 21 AJ - 501 model (Master Series. Based on the results, future studies can choose to focus on specific regions of the these valves.

  2. Laser Doppler anemometry measurements of steady flow through two bi-leaflet prosthetic heart valves

    OpenAIRE

    Ovandir Bazan; Jayme Pinto Ortiz; Francisco Ubaldo Vieira Junior; Reinaldo Wilson Vieira; Nilson Antunes; Fabio Bittencourt Dutra Tabacow; Eduardo Tavares Costa; Orlando Petrucci Junior

    2013-01-01

    INTRODUCTION: In vitro hydrodynamic characterization of prosthetic heart valves provides important information regarding their operation, especially if performed by noninvasive techniques of anemometry. Once velocity profiles for each valve are provided, it is possible to compare them in terms of hydrodynamic performance. In this first experimental study using laser doppler anemometry with mechanical valves, the simulations were performed at a steady flow workbench. OBJECTIVE: To compare unid...

  3. Particle Image Velocimetry Study of Pulsatile Flow in Bi-leaflet Mechanical Heart Valves with Image Compensation Method

    OpenAIRE

    Shi, Yubing; Yeo, Tony Joon Hock; Zhao, Yong; Hwang, Ned H. C.

    2006-01-01

    Particle Image Velocimetry (PIV) is an important technique in studying blood flow in heart valves. Previous PIV studies of flow around prosthetic heart valves had different research concentrations, and thus never provided the physical flow field pictures in a complete heart cycle, which compromised their pertinence for a better understanding of the valvular mechanism. In this study, a digital PIV (DPIV) investigation was carried out with improved accuracy, to analyse the pulsatile flow field ...

  4. High-resolution fluid-structure interaction simulations of flow through a bi-leaflet mechanical heart valve in an anatomic aorta.

    Science.gov (United States)

    Borazjani, Iman; Ge, Liang; Sotiropoulos, Fotis

    2010-02-01

    We have performed high-resolution fluid-structure interaction simulations of physiologic pulsatile flow through a bi-leaflet mechanical heart valve (BMHV) in an anatomically realistic aorta. The results are compared with numerical simulations of the flow through an identical BMHV implanted in a straight aorta. The comparisons show that although some of the salient features of the flow remain the same, the aorta geometry can have a major effect on both the flow patterns and the motion of the valve leaflets. For the studied configuration, for instance, the BMHV leaflets in the anatomic aorta open much faster and undergo a greater rebound during closing than the same valve in the straight axisymmetric aorta. Even though the characteristic triple-jet structure does emerge downstream of the leaflets for both cases, for the anatomic case the leaflet jets spread laterally and diffuse much faster than in the straight aorta due to the aortic curvature and complex shape of the anatomic sinus. Consequently the leaflet shear layers in the anatomic case remain laminar and organized for a larger portion of the accelerating phase as compared to the shear layers in the straight aorta, which begin to undergo laminar instabilities well before peak systole is reached. For both cases, however, the flow undergoes a very similar explosive transition to the small-scale, turbulent-like state just prior to reaching peak systole. The local maximum shear stress is used as a metric to characterize the mechanical environment experienced by blood cells. Pockets of high local maximum shear are found to be significantly more widespread in the anatomic aorta than in the straight aorta throughout the cardiac cycle. Pockets of high local maximum shear were located near the leaflets and in the aortic arc region. This work clearly demonstrates the importance of the aortic geometry on the flow phenomena in a BMHV and demonstrates the potential of our computational method to carry out image

  5. Heart valve surgery

    Science.gov (United States)

    Valve replacement; Valve repair; Heart valve prosthesis; Mechanical valves, Prosthetic valves ... made materials, such as metal (stainless steel or titanium) or ceramic. These valves last the longest, but ...

  6. A biomimetic bi-leaflet mitral prosthesis with enhanced physiological left ventricular swirl restorative capability

    Science.gov (United States)

    Tan, Sean Guo-Dong; Kim, Sangho; Leo, Hwa Liang

    2016-06-01

    Mechanical heart valve prostheses are often implanted in young patients due to their durability and long-term reliability. However, existing designs are known to induce elevated levels of blood damage and blood platelet activation. As a result, there is a need for patients to undergo chronic anti-coagulation treatment to prevent thrombosis, often resulting in bleeding complications. Furthermore, recent studies have suggested that the implantation of a mechanical prosthetic valve at the mitral position results in a significant alteration of the left ventricular flow field which may contribute to flow turbulence. This study proposes a bi-leaflet mechanical heart valve design (Bio-MHV) that mimics the geometry of a human mitral valve, with the aim of reducing turbulence levels in the left ventricle by replicating physiological flow patterns. An in vitro three-dimensional particle velocimetry imaging experiment was carried out to compare the hemodynamic performance of the Bio-MHV with that of the clinically established ATS valve. The Bio-MHV was found to replicate physiological left ventricular flow patterns and produced lower turbulence levels.

  7. Two-dimensional FSI simulation of closing dynamics of a tilting disc mechanical heart valve.

    Science.gov (United States)

    Govindarajan, V; Udaykumar, H S; Herbertson, L H; Deutsch, S; Manning, K B; Chandran, K B

    2010-03-01

    The fluid dynamics during valve closure resulting in high shear flows and large residence times of particles has been implicated in platelet activation and thrombus formation in mechanical heart valves. Our previous studies with bi-leaflet valves have shown that large shear stresses induced in the gap between the leaflet edge and the valve housing results in relatively high platelet activation levels whereas flow between the leaflets results in shed vortices not conducive to platelet damage. In this study we compare the result of closing dynamics of a tilting disc valve with that of a bi-leaflet valve. The two-dimensional fluid-structure interaction analysis of a tilting disc valve closure mechanics is performed with a fixed grid Cartesian mesh flow solver with local mesh refinement, and a Lagrangian particle dynamic analysis for computation of potential for platelet activation. Throughout the simulation the flow remains in the laminar regime and the flow through the gap width is marked by the development of a shear layer which separates from the leaflet downstream of the valve. Zones of re-circulation are observed in the gap between the leaflet edge and the valve housing on the major orifice region of the tilting disc valve and are seen to be migrating towards the minor orifice region. Jet flow is observed at the minor orifice region and a vortex is formed which sheds in the direction of fluid motion as observed in experiments using PIV measurements. The activation parameter computed for the tilting disc valve, at the time of closure was found to be 2.7 times greater than that of the bi-leaflet mechanical valve and was found to be in the vicinity of the minor orifice region mainly due to the migration of vortical structures from the major to the minor orifice region during the leaflet rebound of the closing phase.

  8. Heart Valve Diseases

    Science.gov (United States)

    Your heart has four valves. Normally, these valves open to let blood flow through or out of your heart, and then shut to keep it from flowing ... close tightly. It's one of the most common heart valve conditions. Sometimes it causes regurgitation. Stenosis - when ...

  9. Biological heart valves.

    Science.gov (United States)

    Ciubotaru, Anatol; Cebotari, Serghei; Tudorache, Igor; Beckmann, Erik; Hilfiker, Andres; Haverich, Axel

    2013-10-01

    Cardiac valvular pathologies are often caused by rheumatic fever in young adults, atherosclerosis in elderly patients, or by congenital malformation of the heart in children, in effect affecting almost all population ages. Almost 300,000 heart valve operations are performed worldwide annually. Tissue valve prostheses have certain advantages over mechanical valves such as biocompatibility, more physiological hemodynamics, and no need for life-long systemic anticoagulation. However, the major disadvantage of biological valves is related to their durability. Nevertheless, during the last decade, the number of patients undergoing biological, rather than mechanical, valve replacement has increased from half to more than three-quarters for biological implants. Continuous improvement in valve fabrication includes development of new models and shapes, novel methods of tissue treatment, and preservation and implantation techniques. These efforts are focused not only on the improvement of morbidity and mortality of the patients but also on the improvement of their quality of life. Heart valve tissue engineering aims to provide durable, "autologous" valve prostheses. These valves demonstrate adaptive growth, which may avoid the need of repeated operations in growing patients.

  10. What Is Heart Valve Disease?

    Science.gov (United States)

    ... heart work harder and affect its ability to pump blood. Overview How the Heart Valves Work At the ... into the atria. As the ventricles contract, they pump blood through the pulmonary and aortic valves. The pulmonary ...

  11. Transcatheter Aortic Heart Valve Thrombosis

    DEFF Research Database (Denmark)

    Hansson, Nicolaj C; Grove, Erik L; Andersen, Henning R;

    2016-01-01

    BACKGROUND: There is increasing focus on transcatheter heart valve (THV) thrombosis. However, there are limited data on incidence, clinical implications and predisposing factors of THV thrombosis following transcatheter aortic valve replacement (TAVR). OBJECTIVES: We assessed the incidence...

  12. Developments in mechanical heart valve prosthesis

    Indian Academy of Sciences (India)

    Kalyani Nair; C V Muraleedharan; G S Bhuvaneshwar

    2003-06-01

    Artificial heart valves are engineered devices used for replacing diseased or damaged natural valves of the heart. Most commonly used for replacement are mechanical heart valves and biological valves. This paper briefly outlines the evolution, designs employed, materials being used,. and important factors that affect the performance of mechanical heart valves. The clinical performance of mechanical heart valves is also addressed. Efforts made in India in the development of mechanical heart valves are also discussed.

  13. What Causes Heart Valve Disease?

    Science.gov (United States)

    ... other infections with strep bacteria that progress to rheumatic fever can cause heart valve disease. When the body tries to fight the strep ... you feel better before the medicine is gone. Heart valve disease caused by rheumatic fever mainly affects older adults who had strep ...

  14. How Is Heart Valve Disease Treated?

    Science.gov (United States)

    ... is called a valve-in-valve procedure. Heart-Healthy Lifestyle Changes to Treat Other Related Heart Conditions To ... your doctor may advise you to make heart-healthy lifestyle changes, such as: Heart-healthy eating Aiming for ...

  15. Valve-in-valve-in-valve: Treating endocarditis of a transcatheter heart valve.

    Science.gov (United States)

    Nguyen, Caroline; Cheong, Adrian P; Himbert, Dominique

    2015-10-01

    Transcatheter heart valve endocarditis is a rare, but life threatening complication. We describe the case of a patient who was successfully treated by transcatheter aortic valve-in-valve-in-valve replacement with a favorable 1-year outcome, despite severe early complications.

  16. Percutaneous heart valves; past, present and future.

    Science.gov (United States)

    Rozeik, M M; Wheatley, D J; Gourlay, T

    2014-09-01

    Percutaneous heart valves provide a promising future for patients refused surgery on the grounds of significant technical challenges or high risk for complications. Since the first human intervention more than 10 years ago, over 50 different types of valves have been developed. The CoreValve and Edwards SAPIEN valves have both experienced clinical trials and the latter has gained FDA approval for implantation in patients considered inoperable. Current complications, such as major vascular bleeding and stroke, prevent these valves from being commonly deployed in patients considered operable in conventional surgery. This review focuses on the past and present achievements of these valves and highlights the design considerations required to progress development further. It is envisaged that, with continued improvement in valve design and with increased clinical and engineering experience, percutaneous heart valve replacement may one day be a viable option for lower-risk operable patients.

  17. Heart Valve Disease among Patients with Hyperprolactinaemia

    DEFF Research Database (Denmark)

    Steffensen, Charlotte; Maegbaek, Merete Lund; Laurberg, Peter;

    2012-01-01

    Increased risk of heart valve disease during treatment with certain dopamine agonists, such as cabergoline, has been observed in patients with Parkinson's disease. The same compound is used to treat hyperprolactinemia, but it is unknown whether this also associates with heart valve disease....

  18. Heart Valve Surgery Recovery and Follow Up

    Science.gov (United States)

    ... Stroke More Heart Valve Surgery Recovery and Follow Up Updated:May 27,2016 Surgery Recovery Checklist English | ... self-care and are soon encouraged to get up, to breathe deeply, and to resume eating, drinking ...

  19. Pregnancy-induced remodeling of heart valves.

    Science.gov (United States)

    Pierlot, Caitlin M; Moeller, Andrew D; Lee, J Michael; Wells, Sarah M

    2015-11-01

    Recent studies have demonstrated remodeling of aortic and mitral valves leaflets under the volume loading and cardiac expansion of pregnancy. Those valves' leaflets enlarge with altered collagen fiber architecture, content, and cross-linking and biphasic changes (decreases, then increases) in extensibility during gestation. This study extends our analyses to right-sided valves, with additional compositional measurements for all valves. Valve leaflets were harvested from nonpregnant heifers and pregnant cows. Leaflet structure was characterized by leaflet dimensions, and ECM composition was determined using standard biochemical assays. Histological studies assessed changes in cellular and ECM components. Leaflet mechanical properties were assessed using equibiaxial mechanical testing. Collagen thermal stability and cross-linking were assessed using denaturation and hydrothermal isometric tension tests. Pulmonary and tricuspid leaflet areas increased during pregnancy by 35 and 55%, respectively. Leaflet thickness increased by 20% only in the pulmonary valve and largely in the fibrosa (30% thickening). Collagen crimp length was reduced in both the tricuspid (61%) and pulmonary (42%) valves, with loss of crimped area in the pulmonary valve. Thermomechanics showed decreased collagen thermal stability with surprisingly maintained cross-link maturity. The pulmonary leaflet exhibited the biphasic change in extensibility seen in left side valves, whereas the tricuspid leaflet mechanics remained largely unchanged throughout pregnancy. The tricuspid valve exhibits a remodeling response during pregnancy that is significantly diminished from the other three valves. All valves of the heart remodel in pregnancy in a manner distinct from cardiac pathology, with much similarity valve to valve, but with interesting valve-specific responses in the aortic and tricuspid valves.

  20. Mechanical heart valve cavitation in patients with bileaflet valves.

    Science.gov (United States)

    Johansen, Peter; Andersen, Tina S; Hasenkam, J Michael; Nygaard, Hans; Paulsen, Peter K

    2014-01-01

    Today, the quality of mechanical heart valves is quite high, and implantation has become a routine clinical procedure with a low operative mortality (valves are thought of having higher cavitation potential than bileaflet valves due to higher closing velocities. However, the thromboembolic potential seems to be the same. Further studies are therefore needed to investigate the cavitation potential of bileaflet valves in vivo. The post processing of HFPF have shown difficulties when applied on bileaflet vavles due to asynchronous closure of the two leaflets. The aim of this study was therefore to isolate the pressure signature from each leaflet closure and perform cavitation analyses on each component. Six patients were included in the study (St. Jude Medical (n=3) and CarboMedics (n=3); all aortic bileaflet mechanical heart valves). HFPFs were recorded intraoperatively through a hydrophone at the aortic root. The pressure signature relating to the first and second leaflet closure was isolated and cavitation parameters were calculated (RMS after 50 kHz highpass filtering and signal energy). Data were averaged over 30 heart cycles. For all patients both the RMS value and signal energy of the second leaflet closure were higher than for the first leaflet closure. This indicates that the second leaflet closure is most prone to cause cavitation. Therefore, quantifying cavitation based on the HFPF related to the second leaflet closure may suggest that the cavitation potential for bileaflet valves in vivo may be higher than previous studies have suggested. PMID:25571278

  1. Valve-related complications after mechanical heart valve implantation.

    Science.gov (United States)

    Misawa, Yoshio

    2015-10-01

    The number of heart valve surgeries is increasing, and 19,164 patients underwent heart valve surgery in Japan in 2011. The early mortality rate has remained stable for more than 10 years. Many patients now survive for many years, with a reported 10-year survival rate of at least 60 %. However, unfavorable complications can occur after valve surgery. Valve-related complications include thromboembolisms, bleeding complications and prosthetic valve endocarditis, followed by structural and nonstructural prosthetic valve dysfunctions. Our review of studies published after 2000 revealed that the rate of all valve-related complications was 0.7-3.5 % per patient-year. Thromboembolisms occur at a rate of approximately 1 % per patient-year, and bleeding complications occur at almost 0.5 % per patient-year. Thromboembolic and hemorrhagic events related to anticoagulant therapy should be considered during life-long follow-up. The occurrence rate of endocarditis reaches 0.5 % per patient-year, with a poor postoperative survival. Structural dysfunctions have been largely overcome, and the nonstructural dysfunction rate is 0.4-1.2 % per patient-year. The nonstructural dysfunctions induced by paravalvular leaks and pannus ingrowth are also issues that need to be resolved.

  2. Patents and heart valve surgery - II: tissue valves.

    Science.gov (United States)

    Cheema, Faisal H; Kossar, Alexander P; Rehman, Atiq; Younas, Fahad; Polvani, Gianluca

    2013-08-01

    Valvular heart disease affects millions of Americans yearly and currently requires surgical intervention to repair or replace the defective valves. Through a close-knit collaboration between physicians, scientists and biomedical engineers, a vast degree of research and development has been aimed towards the optimization of prosthetic heart valves. Although various methods have made fantastic strides in producing durable prostheses, the therapeutic efficacy of prosthetic valves is inherently limited by a dependency upon lifelong anticoagulant regimens for recipients - a difficult challenge for many in clinical setting. Thus, biological tissue valves have been developed to circumvent vascular and immunemediated complications by incorporating biological materials to mimic native valves while still maintaining a necessary level of structural integrity. Over the past decade, a multitude of patents pertaining to the refinement of designs as well as the advancement in methodologies and technologies associated with biological tissue valves have been issued. This review seeks to chronicle and characterize such patents in an effort to track the past, present, and future progress as well as project the trajectory of tissue valves in the years to come. PMID:23919429

  3. Patents and heart valve surgery - II: tissue valves.

    Science.gov (United States)

    Cheema, Faisal H; Kossar, Alexander P; Rehman, Atiq; Younas, Fahad; Polvani, Gianluca

    2013-08-01

    Valvular heart disease affects millions of Americans yearly and currently requires surgical intervention to repair or replace the defective valves. Through a close-knit collaboration between physicians, scientists and biomedical engineers, a vast degree of research and development has been aimed towards the optimization of prosthetic heart valves. Although various methods have made fantastic strides in producing durable prostheses, the therapeutic efficacy of prosthetic valves is inherently limited by a dependency upon lifelong anticoagulant regimens for recipients - a difficult challenge for many in clinical setting. Thus, biological tissue valves have been developed to circumvent vascular and immunemediated complications by incorporating biological materials to mimic native valves while still maintaining a necessary level of structural integrity. Over the past decade, a multitude of patents pertaining to the refinement of designs as well as the advancement in methodologies and technologies associated with biological tissue valves have been issued. This review seeks to chronicle and characterize such patents in an effort to track the past, present, and future progress as well as project the trajectory of tissue valves in the years to come.

  4. High readmission rate after heart valve surgery

    DEFF Research Database (Denmark)

    Sibilitz, K L; Berg, S K; Thygesen, L C;

    2015-01-01

    BACKGROUND: After heart valve surgery, knowledge on long-term self-reported health status and readmission is lacking. Thus, the optimal strategy for out-patient management after surgery remains unclear. METHODS: Using a nationwide survey with linkage to Danish registers with one year follow-up, we...... included all adults 6-12 months after heart valve surgery irrespective of valve procedure, during Jan-June 2011 (n = 867). Participants completed a questionnaire regarding health-status (n = 742), and answers were compared with age- and sex-matched healthy controls. Readmission rates and mortality were...... investigated. RESULTS: After valve surgery, the self-reported health was lower (Short Form-36 (SF-36) Physical Component Scale (PCS): 44.5 vs. 50.6 and Mental Component Scale (MCS): 51.9 vs. 55.0, p

  5. Multimodality Imaging of Heart Valve Disease

    Energy Technology Data Exchange (ETDEWEB)

    Rajani, Ronak, E-mail: Dr.R.Rajani@gmail.com [Department of Cardiology, St. Thomas’ Hospital, London (United Kingdom); Khattar, Rajdeep [Department of Cardiology, Royal Brompton Hospital, London (United Kingdom); Chiribiri, Amedeo [Divisions of Imaging Sciences, The Rayne Institute, St. Thomas' Hospital, London (United Kingdom); Victor, Kelly; Chambers, John [Department of Cardiology, St. Thomas’ Hospital, London (United Kingdom)

    2014-09-15

    Unidentified heart valve disease is associated with a significant morbidity and mortality. It has therefore become important to accurately identify, assess and monitor patients with this condition in order that appropriate and timely intervention can occur. Although echocardiography has emerged as the predominant imaging modality for this purpose, recent advances in cardiac magnetic resonance and cardiac computed tomography indicate that they may have an important contribution to make. The current review describes the assessment of regurgitant and stenotic heart valves by multimodality imaging (echocardiography, cardiac computed tomography and cardiac magnetic resonance) and discusses their relative strengths and weaknesses.

  6. 21 CFR 870.3935 - Prosthetic heart valve holder.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Prosthetic heart valve holder. 870.3935 Section 870.3935 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... heart valve holder. (a) Identification. A prosthetic heart valve holder is a device used to hold...

  7. Protocol for relative hydrodynamic assessment of tri-leaflet polymer valves.

    Science.gov (United States)

    Ramaswamy, Sharan; Salinas, Manuel; Carrol, Rob; Landaburo, Karla; Ryans, Xavier; Crespo, Cynthia; Rivero, Ailyn; Al-Mousily, Faris; DeGroff, Curt; Bleiweis, Mark; Yamaguchi, Hitomi

    2013-01-01

    Limitations of currently available prosthetic valves, xenografts, and homografts have prompted a recent resurgence of developments in the area of tri-leaflet polymer valve prostheses. However, identification of a protocol for initial assessment of polymer valve hydrodynamic functionality is paramount during the early stages of the design process. Traditional in vitro pulse duplicator systems are not configured to accommodate flexible tri-leaflet materials; in addition, assessment of polymer valve functionality needs to be made in a relative context to native and prosthetic heart valves under identical test conditions so that variability in measurements from different instruments can be avoided. Accordingly, we conducted hydrodynamic assessment of i) native (n = 4, mean diameter, D = 20 mm), ii) bi-leaflet mechanical (n= 2, D = 23 mm) and iii) polymer valves (n = 5, D = 22 mm) via the use of a commercially available pulse duplicator system (ViVitro Labs Inc, Victoria, BC) that was modified to accommodate tri-leaflet valve geometries. Tri-leaflet silicone valves developed at the University of Florida comprised the polymer valve group. A mixture in the ratio of 35:65 glycerin to water was used to mimic blood physical properties. Instantaneous flow rate was measured at the interface of the left ventricle and aortic units while pressure was recorded at the ventricular and aortic positions. Bi-leaflet and native valve data from the literature was used to validate flow and pressure readings. The following hydrodynamic metrics were reported: forward flow pressure drop, aortic root mean square forward flow rate, aortic closing, leakage and regurgitant volume, transaortic closing, leakage, and total energy losses. Representative results indicated that hydrodynamic metrics from the three valve groups could be successfully obtained by incorporating a custom-built assembly into a commercially available pulse duplicator system and subsequently, objectively compared to provide

  8. Multimodality Imaging Assessment of Prosthetic Heart Valves

    NARCIS (Netherlands)

    Suchá, D.; Symersky, Petr; Tanis, W; Mali, Willem P Th M; Leiner, Tim; van Herwerden, LA; Budde, Ricardo P J

    2015-01-01

    Echocardiography and fluoroscopy are the main techniques for prosthetic heart valve (PHV) evaluation, but because of specific limitations they may not identify the morphological substrate or the extent of PHV pathology. Cardiac computed tomography (CT) and magnetic resonance imaging (MRI) have emerg

  9. DONOR HEART VALVES RECONSTRUCTION BEFORE TRANSPLANTATION

    Directory of Open Access Journals (Sweden)

    S. V. Gautier

    2013-01-01

    Full Text Available Aim of study. The demonstration of our own experience in heart transplantation after valve reconstruction. Methods and results. From May 2012 to March 2013 3 mitral valve annuloplasties were performed to recipi- ents, requiring urgent HT and having extremely unfavorable prognosis of survival without HT. The recipients were classified as United Network for Organ Sharing (UNOS IB, and all of them were on inotropic support. In one case, HT was performed after reconstruction of rheumatic mitral stenosis, in two other cases – after dege- nerative mitral regurgitation. The technical aspects are reviewed of ex-vivo mitral and tricuspid valves repair with concomitant heart transplantation. All patients were discharged from the hospital having excellent postope- rative recovery. Conclusion. Taking into consideration the demonstrated satisfactory result of surveillance and presence of significant experience in performing of reconstructive valve surgery among no-HT cardiosurgical patients, an increase in the pool of suitable donor organs is expected due to the liberalization of the selection criteria and the possibility of the innovative valve reconstruction procedures ex vivo. 

  10. Pathogenic Mineralization of Calcium Phosphate on Human Heart Valves

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    When calcium phosphate forms in soft tissues such as blood vessels and heart valves, it causes disease. The abnormal formation of calcium phosphate is called pathogenic mineralization or pathogenic calcification. Cases of rheumatic heart disease (RHD) always occur with fibrotic and calcified tissue of heart valve. In this article, samples taken from calcified human heart valves were studied. The characterization was performed by scanning electronic micrascope, X-ray Diffraction and transmission electron microscopy with selective diffraction patterns. It is found for the first time that calcium phosphate grains existing in the calcified human heart valves contain octacalcium phosphate (OCP).

  11. Tubular heart valves from decellularized engineered tissue.

    Science.gov (United States)

    Syedain, Zeeshan H; Meier, Lee A; Reimer, Jay M; Tranquillo, Robert T

    2013-12-01

    A novel tissue-engineered heart valve (TEHV) was fabricated from a decellularized tissue tube mounted on a frame with three struts, which upon back-pressure cause the tube to collapse into three coapting "leaflets." The tissue was completely biological, fabricated from ovine fibroblasts dispersed within a fibrin gel, compacted into a circumferentially aligned tube on a mandrel, and matured using a bioreactor system that applied cyclic distension. Following decellularization, the resulting tissue possessed tensile mechanical properties, mechanical anisotropy, and collagen content that were comparable to native pulmonary valve leaflets. When mounted on a custom frame and tested within a pulse duplicator system, the tubular TEHV displayed excellent function under both aortic and pulmonary conditions, with minimal regurgitant fractions and transvalvular pressure gradients at peak systole, as well as well as effective orifice areas exceeding those of current commercially available valve replacements. Short-term fatigue testing of one million cycles with pulmonary pressure gradients was conducted without significant change in mechanical properties and no observable macroscopic tissue deterioration. This study presents an attractive potential alternative to current tissue valve replacements due to its avoidance of chemical fixation and utilization of a tissue conducive to recellularization by host cell infiltration.

  12. Microscopic and ultramicroscopic characteristic of heart valves in human

    Directory of Open Access Journals (Sweden)

    Fedoniuk L.

    2014-09-01

    Full Text Available Background. Valvular apparatus of the heart is the frequent object of the surgical operations for today. Morphological changes which are happed within valves of the heart at time of cardiac diseases the modern medicine considers on the clinical, instrumental, histological, cytological and ultramicroscopical levels. The cardiac surgeons that make the heart valve replacement using the tissue engineering have the great interest in front of the heart valves. The achievements of the modern medicine are impossible without the fundamental morphological investigations. Objective. To study the morphological features of the cusps of human heart valves on the light and ultramicroscopic levels. Methods. We have reviewed the structure of cusps of 48 heart valves of adults. It was used a light and electron microscopy which enabled us to study the morphology of cusps of atria-ventricular and ventriculo-vascular heart valves. Results. The data indicate that cusps of heart valves are stratified. Layers of cusps are made of different types of fibrous connective tissues. The spongy layer is made of loose connective tissue, the fibrous layer – dense regular connective tissue, ventricular layer – dense irregular connective tissue. The arrangement of these layers in the cusps of atria-ventricular heart valves (in the direction from atrium toward ventricle is: spongy, fibrous and ventricular. The arrangement of these layers in the cusps of ventricular-vascular heart valves (in the direction from side that is faced to the wall of blood vessel toward the ventricle is: fibrous, spongy, ventricular. Conclusion. The position of data layers within cusp of atria-ventricular valves differs from position of data layers within ventriculo-vascular valves. These changes of tissue localization correlate to haemodynamic conditions during heart cycle. Citation: Fedoniuk L, Semeniuk T, Bodnar E. [Microscopic and ultramicroscopic characteristic of heart valves in human

  13. Anticoagulation property and security of artificial heart valve material

    Institute of Scientific and Technical Information of China (English)

    WANG; Xianghui; LIU; Xianghuai; ZHANG; Feng; LI; Changron

    2005-01-01

    Heart valve diseases threaten human health. One reliable way to save lives of such patients is to replace the pathologically changed heart valves by artificial ones. Over 2 million patients have received LTI-carbon heart valve's implantation. However, the thrombosis after the implantation is one of the difficulties that need to be solved. In order to improve the blood compatibility and security of mechanical heart valves, ion beam technology was used to modify the surface properties of the materials. The investigation results have been summarized in this paper.

  14. Prosthetic heart valves: Objective Performance Criteria versus randomized clinical trial.

    Science.gov (United States)

    Grunkemeier, Gary L; Jin, Ruyun; Starr, Albert

    2006-09-01

    The current Food and Drug Administration (FDA) heart valve guidance document uses an objective performance criteria (OPC) methodology to evaluate the clinical performance of prosthetic heart valves. OPC are essentially historical controls, but they have turned out to be an adequate, and perhaps optimal, study design in this situation. Heart valves have a simple open-and-close mechanism, device effectiveness is easy to document, and the common complications (thromboembolism, thrombosis, bleeding, leak, and infection) are well known and easily detected. Thus, randomized clinical trials (RCTs) have not been deemed necessary for the regulatory approval of prosthetic heart valves. The OPC are derived from the average complication rates of all approved heart valves. Studies based on OPC have been shown to work well; many different valve models have gained FDA market approval based on this methodology. Although heart valve RCTs are not required by the FDA, they have been done to compare valves or treatment regimens after approval. Recently, the Artificial Valve Endocarditis Reduction Trial (AVERT) was designed to compare a new Silzone sewing ring, designed to reduce infection, with the Standard sewing ring on a St. Jude Medical heart valve. This was the largest heart valve RCT ever proposed (4,400 valve patients, followed for as long as 4 years), but it was stopped prematurely because of a high leak rate associated with the Silzone valve. Examining the results showed that a much smaller, OPC-based study with 800 patient-years would have been sufficient to disclose this complication of the Silzone valve. PMID:16928482

  15. Physical activity increases survival after heart valve surgery

    DEFF Research Database (Denmark)

    Lund, K.; Sibilitz, Kirstine Lærum; Kikkenborg berg, Selina;

    2016-01-01

    OBJECTIVES: Increased physical activity predicts survival and reduces risk of readmission in patients with coronary heart disease. However, few data show how physical activity is associated with survival and readmission after heart valve surgery. Objective were to assess the association between...... physical activity levels 6-12 months after heart valve surgery and (1) survival, (2) hospital readmission 18-24 months after surgery and (3) participation in exercise-based cardiac rehabilitation. METHODS: Prospective cohort study with registry data from The CopenHeart survey, The Danish National Patient...... of physical activity after heart valve surgery are positively associated with higher survival rates and participation in cardiac rehabilitation....

  16. Heart valve clinic: rationale and organization.

    Science.gov (United States)

    Lancellotti, Patrizio; Rosenhek, Raphael; Pibarot, Philippe

    2014-09-01

    With an increasing prevalence of patients with valvular heart disease (VHD), a dedicated management approach delivered in a well-defined structure, namely, the heart valve clinic (HVC), is warranted. The HVC is made up of a multidisciplinary team with high expertise in the diagnosis, management, treatment, and surveillance of patients with VHD. The aim of the HVC is to provide the highest quality of care to patients with VHD to improve the level of adherence to current evidence and guidelines, quality of life, and short- and long-term outcomes. The HVC also provides help in (1) informing and educating patients to motivate them to take their prescribed medications and look out for signs indicating a worsening of their disease, (2) organizing meetings for updates in knowledge for modern management of patients with VHD, and (3) disseminating protocols of contemporary and good practice in VHD.

  17. Make Your Own Working Models of Heart Valves!

    Science.gov (United States)

    Hudson, Margaret L.

    2014-01-01

    Heart valves play a vital role in efficient circulation of the blood, and the details of their physical structure are related crucially to their function. However, it can be challenging for the learner to make the mental connection between anatomical structures of valves and the changing pressure gradients that the valves experience and come to an…

  18. Signal processing of Shiley heart valve data for fracture detection

    Energy Technology Data Exchange (ETDEWEB)

    Mullenhoff, C.

    1993-09-01

    Given digital acoustic data emanating from the heart sounds of the beating heart measured from laboratory sheep with implanted Bjoerk-Shiley Convexo-Concave heart valves, it is possible to detect and extract the opening and closing heart beats from the data. Once extracted, spectral or other information can then obtained from the heartbeats and passed on to feature extraction algorithms, neural networks, or pattern recognizers so that the valve condition, either fractured or intact, may be determined.

  19. Signal processing of Shiley heart valve data for fracture detection

    Energy Technology Data Exchange (ETDEWEB)

    Mullenhoff, C.

    1993-04-01

    Given digital acoustic data emanating from the heart sounds of the beating heart measured from laboratory sheep with implanted Bjoerk-Shiley Convexo-Concave heart valves, it is possible to detect and extract the opening and closing heart beats from the data. Once extracted, spectral or other information can then obtained from the heartbeats and passed on to feature extraction algorithms, neutral networks, or pattern recognizers so that the valve condition, either fractured or intact, may be determined.

  20. Cardiac crossroads: deciding between mechanical or bioprosthetic heart valve replacement

    Directory of Open Access Journals (Sweden)

    Maggie N Tillquist

    2011-02-01

    Full Text Available Maggie N Tillquist1, Thomas M Maddox21School of Medicine, University of Colorado Denver, Denver, CO, USA; 2VA Eastern Colorado Health Care System, and Department of Medicine (Cardiology, University of Colorado Denver, Denver, CO, USAAbstract: Nearly 15 million people in the United States suffer from either aortic or mitral valvular disease. For patients with severe and symptomatic valvular heart disease, valve replacement surgery improves morbidity and mortality outcomes. In 2009, 90,000 valve replacement surgeries were performed in the United States. This review evaluates the advantages and disadvantages of mechanical and bioprosthetic prosthetic heart valves as well as the factors for consideration in deciding the appropriate valve type for an individual patient. Although many caveats exist, the general recommendation is for patients younger than 60 to 65 years to receive mechanical valves due to the valve's longer durability and for patients older than 60 to 65 years to receive a bioprosthetic valve to avoid complications with anticoagulants. Situations that warrant special consideration include patient co-morbidities, the need for anticoagulation, and the potential for pregnancy. Once these characteristics have been considered, patients' values, anxieties, and expectations for their lifestyle and quality of life should be incorporated into final valve selection. Decision aids can be useful in integrating preferences in the valve decision. Finally, future directions in valve technology, anticoagulation, and medical decision-making are discussed.Keywords: prosthetic heart valves, patient preference, valve type, anticoagulant, structural valve deterioration 

  1. The development of transcatheter heart valves: opportunities and challenges.

    Science.gov (United States)

    Laske, Tim; Denton, Melissa; Eberhardt, Carol

    2009-01-01

    Although the heart valve market is relatively mature, many patients currently indicated for valve repair or replacement are either undiagnosed, not referred for surgery, or are too sick/unwilling to undergo the required surgery (Table I). To address this unmet clinical need, the medical device industry has undertaken the development of transcatheter heart valves (TCV). These devices are tissue heart valves that can be delivered without open heart surgery and are intended to complement the portfolio of current and future surgical valve products. Several companies have developed novel product designs. Some transcatheter valves are currently available for the aortic and pulmonic positions via European CE mark, and are in clinical trials throughout the United States. PMID:19963953

  2. Heart valve disease: investigation by cardiovascular magnetic resonance

    OpenAIRE

    Myerson Saul G

    2012-01-01

    Abstract Cardiovascular magnetic resonance (CMR) has become a valuable investigative tool in many areas of cardiac medicine. Its value in heart valve disease is less well appreciated however, particularly as echocardiography is a powerful and widely available technique in valve disease. This review highlights the added value that CMR can bring in valve disease, complementing echocardiography in many areas, but it has also become the first-line investigation in some, such as pulmonary valve di...

  3. Effect of comprehensive cardiac rehabilitation after heart valve surgery (CopenHeartVR)

    DEFF Research Database (Denmark)

    Sibilitz, Kirstine Laerum; Berg, Selina Kikkenborg; Hansen, Tina Birgitte;

    2013-01-01

    Heart valve diseases are common with an estimated prevalence of 2.5% in the Western world. The number is rising due to an ageing population. Once symptomatic, heart valve diseases are potentially lethal, and heavily influence daily living and quality of life. Surgical treatment, either valve repl...

  4. Automatic measuring of quality criteria for heart valves

    Science.gov (United States)

    Condurache, Alexandru Paul; Hahn, Tobias; Hofmann, Ulrich G.; Scharfschwerdt, Michael; Misfeld, Martin; Aach, Til

    2007-03-01

    Patients suffering from a heart valve deficiency are often treated by replacing the valve with an artificial or biological implant. In case of biological implants, the use of porcine heart valves is common. Quality assessment and inspection methods are mandatory to supply the patients (and also medical research) with only the best such xenograft implants thus reducing the number of follow-up surgeries to replace worn-up valves. We describe an approach for automatic in-vitro evaluation of prosthetic heart valves in an artificial circulation system. We show how to measure the orifice area during a heart cycle to obtain an orifice curve. Different quality parameters are then estimated on such curves.

  5. Processing of prosthetic heart valve sounds for classification. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Candy, J.V.; Jones, H.E.

    1994-04-01

    People with serious heart conditions have had their expected life span extended considerably with the development of the prosthetic heart valve especially with the great strides made in valve design. Even though the designs are extremely reliable, the valves are mechanical and operating continuously over a long period, therefore, structural failures can occur due to fatigue. Measuring heart sounds non-invasively in a noisy environment puts more demands on the signal processing to extract the desired signals from the noise. In this paper the authors discuss acoustical signal processing techniques developed to process noisy heart valve sounds measured by a sensitive, surface contact microphone and used for the eventual classification of the valve.

  6. Comparison of heart valve culture between two Danish endocarditis centres

    DEFF Research Database (Denmark)

    Voldstedlund, Marianne; Fuursted, Kurt; Bruun, Niels Eske;

    2012-01-01

    The degree to which the results of valve culture depend on different laboratory procedures as well as other factors is unknown. The aim of this study was to compare the results of heart valve culture at 2 different endocarditis centres in order to clarify this.......The degree to which the results of valve culture depend on different laboratory procedures as well as other factors is unknown. The aim of this study was to compare the results of heart valve culture at 2 different endocarditis centres in order to clarify this....

  7. In-vitro calcification study of polyurethane heart valves.

    Science.gov (United States)

    Boloori Zadeh, Parnian; Corbett, Scott C; Nayeb-Hashemi, Hamid

    2014-02-01

    Tri-leaflet polyurethane heart valves have been considered as a potential candidate in heart valve replacement surgeries. In this study, polyurethane (Angioflex(®)) heart valve prostheses were fabricated using a solvent-casting method to evaluate their calcification resistance. These valves were subjected to accelerated life testing (continuous opening and closing of the leaflets) in a synthetic calcification solution. Results showed that Angioflex(®) could be considered as a potential material for fabricating prosthetic heart valves with possibly a higher calcification resistance compared to tissue valves. In addition, calcification resistance of bisphosphonate-modified Angioflex(®) valves was also evaluated. Bisphosphonates are considered to enhance the calcification resistance of polymers once covalently bonded to the bulk of the material. However, our in-vitro results showed that bisphosphonate-modified Angioflex(®) valves did not improve the calcification resistance of Angioflex(®) compared to its untreated counterparts. The results also showed that cyclic loading of the valves' leaflets resulted in formation of numerous cracks on the calcified surface, which were not present when calcification study did not involve mechanical loading. Further study of these cracks did not result in enough evidence to conclude whether these cracks have penetrated to the polymeric surface.

  8. Classification of heart valve condition using acoustic measurements

    Energy Technology Data Exchange (ETDEWEB)

    Clark, G. [Lawrence Livermore National Lab., CA (United States)

    1994-11-15

    Prosthetic heart valves and the many great strides in valve design have been responsible for extending the life spans of many people with serious heart conditions. Even though the prosthetic valves are extremely reliable, they are eventually susceptible to long-term fatigue and structural failure effects expected from mechanical devices operating over long periods of time. The purpose of our work is to classify the condition of in vivo Bjork-Shiley Convexo-Concave (BSCC) heart valves by processing acoustic measurements of heart valve sounds. The structural failures of interest for Bscc valves is called single leg separation (SLS). SLS can occur if the outlet strut cracks and separates from the main structure of the valve. We measure acoustic opening and closing sounds (waveforms) using high sensitivity contact microphones on the patient`s thorax. For our analysis, we focus our processing and classification efforts on the opening sounds because they yield direct information about outlet strut condition with minimal distortion caused by energy radiated from the valve disc.

  9. Exercise-based cardiac rehabilitation after heart valve surgery

    DEFF Research Database (Denmark)

    Hansen, T B; Zwisler, Ann-Dorthe; Berg, S K;

    2015-01-01

    BACKGROUND: Owing to a lack of evidence, patients undergoing heart valve surgery have been offered exercise-based cardiac rehabilitation (CR) since 2009 based on recommendations for patients with ischaemic heart disease in Denmark. The aim of this study was to investigate the impact of CR...... on the costs of healthcare use and sick leave among heart valve surgery patients over 12 months post surgery. METHODS: We conducted a nationwide survey on the CR participation of all patients having undergone valve surgery between 1 January 2011 and 30 June 2011 (n=667). Among the responders (n=500, 75...... expensive outpatient visits. Further studies should investigate the benefits of CR to heart valve surgery patients as part of a formal cost-utility analysis....

  10. PIV Measurements of flow downstream of polyurethane heart valve prosthesis for artificial heart: steady flow experiment

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J.K.; Sung, J.Y. [Seoul National University Graduate School, Seoul (Korea); Chang, J.K.; Yoo, J.Y.; Min, B.G. [Seoul National University, Seoul (Korea)

    1999-12-01

    Hemodynamic performance of a polyurethane heart valve prosthesis was evaluated in comparison with that of Bjork-Shiley Monostrut mechanical valve in steady flow representing the systolic peak flow phase. Pressure losses through the valves were obtained from the streamwise pressure distributions downstream of the valves. Unsteady and turbulent flow field distal to the heart valve prostheses were investigated using PIV(Particle Image Velocimetry) which can measure the full-field velocity instantaneously and noninvasively. By examining the velocity and Reynolds shear stress fields downstream of the polyurethane heart valve, it is known that there is a large recirculation region near the valve and high shear stress regions exist at the interface between strong axial jet flows along the wall and vortical flows in the central area. The possibilities of vascular complications, such as the thrombus formation and red blood cell damage, could be predicted from the overall view of the velocity and stress fields. (author). 22 refs., 9 figs., 1 tab.

  11. Availability of, referral to and participation in exercise-based cardiac rehabilitation after heart valve surgery

    DEFF Research Database (Denmark)

    Hansen, Tina B; Berg, Selina K; Sibilitz, Kirstine L;

    2015-01-01

    BACKGROUND: As with ischaemic heart disease, cardiac rehabilitation (CR) is recommended for patients undergoing heart valve surgery; recommendations are based on limited evidence. The organization of CR programmes and factors associated with uptake among patients undergoing heart valve surgery have...

  12. Fluid Mechanics of Heart Valves and Their Replacements

    Science.gov (United States)

    Sotiropoulos, Fotis; Le, Trung Bao; Gilmanov, Anvar

    2016-01-01

    As the pulsatile cardiac blood flow drives the heart valve leaflets to open and close, the flow in the vicinity of the valve resembles a pulsed jet through a nonaxisymmetric orifice with a dynamically changing area. As a result, three-dimensional vortex rings with intricate topology emerge that interact with the complex cardiac anatomy and give rise to shear layers, regions of recirculation, and flow instabilities that could ultimately lead to transition to turbulence. Such complex flow patterns, which are inherently valve- and patient-specific, lead to mechanical forces at scales that can cause blood cell damage and thrombosis, increasing the likelihood of stroke, and can trigger the pathogenesis of various life-threatening valvular heart diseases. We summarize the current understanding of flow phenomena induced by heart valves, discuss their linkage with disease pathways, and emphasize the research advances required to translate in-depth understanding of valvular hemodynamics into effective patient therapies.

  13. Fluid Dynamic Characterization of a Polymeric Heart Valve Prototype (Poli-Valve) tested under Continuous and Pulsatile Flow Conditions

    Science.gov (United States)

    De Gaetano, Francesco; Serrani, Marta; Bagnoli, Paola; Brubert, Jacob; Stasiak, Joanna; Moggridge, Geoff D.; Costantino, Maria Laura

    2016-01-01

    Introduction Only mechanical and biological heart valve prostheses are currently commercially available. The former show longer durability but require anticoagulant therapy, the latter display better fluid dynamic behaviour but do not have adequate durability. New Polymeric Heart Valves (PHVs) could potentially combine the haemodynamic properties of biological valves with the durability of mechanical valves. This work presents a hydrodynamic evaluation of two groups of newly developed supra-annular tri-leaflet prosthetic heart valves made from styrenic block copolymers (SBC): Poli-Valves. Methods Two types of Poli-Valves made of SBC differing in polystyrene fraction content were tested under continuous and pulsatile flow conditions as prescribed by ISO 5840 Standard. An ad - hoc designed pulse duplicator allowed the valve prototypes to be tested at different flow rates and frequencies. Pressure and flow were recorded; pressure drops, effective orifice area (EOA), and regurgitant volume were computed to assess the valve’s behaviour. Results Both types Poli-Valves met the minimum requirements in terms of regurgitation and EOA as specified by ISO 5840 Standard. Results were compared with five mechanical heart valves (MHVs) and five tissue heart valves (THVs), currently available on the market. Conclusion Based on these results, polymeric heart valves based on styrenic block copolymers, as Poli-Valves are, can be considered as promising alternative for heart valve replacement in near future. PMID:26689146

  14. Heart Valve Structure and Function in Development and Disease

    Science.gov (United States)

    Hinton, Robert B.; Yutzey, Katherine E.

    2014-01-01

    The mature heart valves are made up of highly organized extracellular matrix (ECM) and valve interstitial cells (VIC) surrounded by an endothelial cell layer. The ECM of the valves is stratified into elastin-, proteoglycan- and collagen-rich layers that confer distinct biomechanical properties to the leaflets and supporting structures. Signaling pathways have critical functions in primary valvulogenesis as well as maintenance of valve structure and function over time. Animal models provide powerful tools to study valve development and disease processes. Valve disease is a significant public health problem and increasing evidence implicates aberrant developmental mechanisms underlying pathogenesis. Further studies are necessary to determine regulatory pathway interactions underlying pathogenesis in order to generate new avenues for novel therapeutics. PMID:20809794

  15. Twenty-Two-Year Experience with Aortic Valve Replacement: Starr-Edwards Ball Valves versus Disc Valves

    OpenAIRE

    Pilegaard, Hans K.; Lund, Ole; Nielsen, Torsten T; Magnussen, Karin; Knudsen, Mary A; Albrechtsen, Ole K.

    1991-01-01

    From 1965 through 1986, 817 patients underwent aortic valve replacement at our institution. Six hundred forty-five patients received Starr-Edwards ball valves, including 286 Silastic ball valves (Models 1200/1260), 165 cloth-covered caged-ball prostheses (Models 2300/2310/2320), and 194 track-valve prostheses (Model 2400). In contrast, 172 patients received disc-valve prostheses, including 126 St. Jude Medical aortic bi-leaflet disc valves, 32 Lillehei-Kaster pivoting disc valves, and 14 Björ...

  16. Signs of inflammation in different types of heart valve disease : The VOCIN study

    OpenAIRE

    Wallby, Lars

    2008-01-01

    Heart valve dysfunction is a relatively common condition in the population, whereas significant heart valve disease is more unusual. The cause of different types of heart valve disease depends on which valve is concerned. Rheumatic heart valve disease, has for a long time been considered to constitute a post-inflammatory condition. During the 1990s it was also shown that the so-called non-rheumatic or degenerative tricuspid aortic stenosis, comprised signs of inflammation. In this study, 118 ...

  17. The echocardiography of replacement heart valves

    Science.gov (United States)

    2016-01-01

    This is a practical description of how replacement valves are assessed using echocardiography. Normal transthoracic appearances including normal variants are described. The problem of differentiating normal function, patient–prosthesis mismatch and pathological obstruction in aortic replacement valves with high gradients is discussed. Obstruction and abnormal regurgitation is described for valves in the aortic, mitral and right-sided positions and when to use echocardiography in suspected infective endocarditis. The roles of transoesophageal and stress echocardiography are described and finally when other imaging techniques may be useful. PMID:27600454

  18. Expression of the CD44 Protein in the Heart Valves Affected with Rheumatic Heart Disease

    Directory of Open Access Journals (Sweden)

    R. Vijayalakshmi

    2010-01-01

    Full Text Available Problem statement: The primary aim was to study the expression of CD44 protein in the heart valves removed surgically for either stenosis or regurgitation and to study the morphology of valves using histochemical staining. Approach: We studied 107 valves which were collected from the International Centre for Cardio Thoracic and Vascular Diseases. Results: Aortic and mitral valves were obtained from the centre and processed in research pathology lab. CD44 protein is a receptor for the ligand hyaluronic acid which causes inflammation in the heart valves. A total of 107 valves were studied. Of the 61 mitral valves studied 38 (62.2% showed CD44 positivity as brownish granules within the cytoplasm. Of the 46 aortic valves studied 19 (41.3% showed CD44 positivity as brownish granules within the cytoplasm. The valves showed evidence of past inflammation showing thick and thin walled blood vessels and lymphocytes. CD44 protein increased in 62.2% of mitral valves, of which 60.5% were from patients presenting when they were less than 40 years old. CD44 protein increased in 41.3% of aortic valves, of which 63.15% were from patients presenting when they were less than 40 years old. CD44 positivity was seen in 57 valves as brownish granules within the cytoplasm of the cell. CD44 protein increased in 53.27% of mitral and aortic valves, of which 63.15% were from the males patients. CD44 protein increased in 53.27% of mitral and aortic valves, of which 36.84% were from the females patients. Conclusion/Recommendations: The results showed CD44 is over expressed in the heart valves removed surgically for stenosis or regurgitation where the hyaluronic acid content is high.

  19. A new approach to heart valve tissue engineering

    DEFF Research Database (Denmark)

    Kaasi, Andreas; Cestari, Idágene A.; Stolf, Noedir A G.;

    2011-01-01

    and flow were registered downstream of the TE valve. The circuit was filled with culture medium and fitted in a standard 5% CO(2) incubator set at 37 °C. Pressure and flow waveforms were similar to those obtained under physiological conditions for the pulmonary circulation. The 'cardiomimetic' approach......The 'biomimetic' approach to tissue engineering usually involves the use of a bioreactor mimicking physiological parameters whilst supplying nutrients to the developing tissue. Here we present a new heart valve bioreactor, having as its centrepiece a ventricular assist device (VAD), which exposes...... chamber. Subsequently, applied vacuum to the pneumatic chamber causes the blood chamber to fill. A mechanical heart valve was placed in the VAD's inflow position. The tissue engineered (TE) valve was placed in the outflow position. The VAD was coupled in series with a Windkessel compliance chamber...

  20. Dynamic Heterogeneity of the Heart Valve Interstitial Cell Population in Mitral Valve Health and Disease

    Directory of Open Access Journals (Sweden)

    Tori E. Horne

    2015-08-01

    Full Text Available The heart valve interstitial cell (VIC population is dynamic and thought to mediate lay down and maintenance of the tri-laminar extracellular matrix (ECM structure within the developing and mature valve throughout life. Disturbances in the contribution and distribution of valve ECM components are detrimental to biomechanical function and associated with disease. This pathological process is associated with activation of resident VICs that in the absence of disease reside as quiescent cells. While these paradigms have been long standing, characterization of this abundant and ever-changing valve cell population is incomplete. Here we examine the expression pattern of Smooth muscle α-actin, Periostin, Twist1 and Vimentin in cultured VICs, heart valves from healthy embryonic, postnatal and adult mice, as well as mature valves from human patients and established mouse models of disease. We show that the VIC population is highly heterogeneous and phenotypes are dependent on age, species, location, and disease state. Furthermore, we identify phenotypic diversity across common models of mitral valve disease. These studies significantly contribute to characterizing the VIC population in health and disease and provide insights into the cellular dynamics that maintain valve structure in healthy adults and mediate pathologic remodeling in disease states.

  1. [Heart valves after 22 years - good long-term function of aortic homograft, advanced impairment in function of atrioventricular valves].

    Science.gov (United States)

    Michalski, Błazej; Chrzanowski, Lukasz; Krzemińska-Pakula, Maria; Kasprzak, Jarosław D

    2010-03-01

    We report a case of a 61-year-old female patient with a history of aortic valve replacement, who was admitted to our hospital with symptoms and signs of decompensated heart failure (NYHA class III). Transthoracic echocardiogram revealed mitral valve and tricuspid valve regurgitation (III grade) with normal function of aortic valve homograft implanted 22 years ago. The patient underwent cardiosurgical mitral valve replacement and tricuspid valve annuloplasty with very good result. An aortic valve homograft may be the best alternative to a mechanical valves for a young female patients. PMID:20411462

  2. A patient with four artificial heart valves after ergotamine therapy

    OpenAIRE

    Bijl, M.; Galema, T. W.; Van Herwerden, L. A.; Kofflard, M.J.M.; Breuls, P.N.W.M.; van de Brink, R.B.A.

    2006-01-01

    A 67-year-old female was evaluated in the out-patient clinic because of shortness of breath on exertion and regular spells of fever. She had been taking ergotamine tartrate to treat migraine for more than 30 years. The patient had undergone aortic-valve replacement for aortic insufficiency three years before. On echocardiographic evaluation, severe retraction and insufficiency of the remaining native heart valves was demonstrated. Endocarditis and carcinoid syndrome were excluded. The mitral,...

  3. Heart valve disease: investigation by cardiovascular magnetic resonance

    Directory of Open Access Journals (Sweden)

    Myerson Saul G

    2012-01-01

    Full Text Available Abstract Cardiovascular magnetic resonance (CMR has become a valuable investigative tool in many areas of cardiac medicine. Its value in heart valve disease is less well appreciated however, particularly as echocardiography is a powerful and widely available technique in valve disease. This review highlights the added value that CMR can bring in valve disease, complementing echocardiography in many areas, but it has also become the first-line investigation in some, such as pulmonary valve disease and assessing the right ventricle. CMR has many advantages, including the ability to image in any plane, which allows full visualisation of valves and their inflow/outflow tracts, direct measurement of valve area (particularly for stenotic valves, and characterisation of the associated great vessel anatomy (e.g. the aortic root and arch in aortic valve disease. A particular strength is the ability to quantify flow, which allows accurate measurement of regurgitation, cardiac shunt volumes/ratios and differential flow volumes (e.g. left and right pulmonary arteries. Quantification of ventricular volumes and mass is vital for determining the impact of valve disease on the heart, and CMR is the 'Gold standard' for this. Limitations of the technique include partial volume effects due to image slice thickness, and a low ability to identify small, highly mobile objects (such as vegetations due to the need to acquire images over several cardiac cycles. The review examines the advantages and disadvantages of each imaging aspect in detail, and considers how CMR can be used optimally for each valve lesion.

  4. In vitro heart valve testing: steady versus pulsatile flow.

    Science.gov (United States)

    Black, M M; Hose, D R; Lamb, C J; Lawford, P V; Ralph, S J

    1994-03-01

    The design of artificial heart valves has traditionally been based on the development of a prototype device which was then subjected to extensive laboratory testing in order to confirm its suitability for clinical use. In the past the in vitro assessment of a valve's performance was based principally on the measurement of parameters such as pressure difference, regurgitation and, more recently, energy losses. Such measurements can be defined as being at the 'macro' level and rarely show any clinically significant differences amongst currently available prostheses. The analytical approach to flow through heart valves has previously been hampered by difficulties experienced in solving the relevant equations of flow particularly in the case of pulsatile conditions. Computational techniques are now available which enable appropriate solutions to be obtained for these problems and consequently provide an opportunity for detailed examination of the 'micro' level of flow disturbances exhibited by the different valves. This present preliminary study is designed to illustrate the use of such an analytical approach to the flow through prosthetic valves. A single topic has been selected for this purpose which is the comparative value of steady versus pulsatile flow testing. A bileaflet valve was chosen for the analysis and a mathematical model of this valve in the aortic position of the Sheffield Pulse Duplicator was created. The theoretical analysis was carried out using a commercially available Computational Fluid Dynamics package, namely, FIDAP, on a SUN MICROSYSTEMS 10-30 workstation.(ABSTRACT TRUNCATED AT 250 WORDS)

  5. Processing of Prosthetic Heart Valve Sounds from Anechoic Tank Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Candy, J V; Meyer, A W

    2001-03-20

    People with serious cardiac problems have had their life span extended with the development of the prosthetic heart valve. However, the valves operate continuously at approximately 39 million cycles per year and are therefore subject to structural failures either by faulty design or material fatigue. The development of a non-invasive technique using an acoustic contact microphone and sophisticated signal processing techniques has been proposed and demonstrated on limited data sets. In this paper we discuss an extension of the techniques to perform the heart valve tests in an anechoic like. Here the objective is to extract a ''pure'' sound or equivalently the acoustical vibration response of the prosthetic valves in a quiet environment. The goal is to demonstrate that there clearly exist differences between values which have a specific mechanical defect known as single leg separation (SLS) and non-defective valves known as intact (INT). We discuss the signal processing and results of anechoic acoustic measurements on 50 prosthetic valves in the tank. Finally, we show the results of the individual runs for each valve, point out any of the meaningful features that could be used to distinguish the SLS from INT and summarize the experiments.

  6. Effects of bileaflet mechanical heart valve orientation on coronary flow

    Science.gov (United States)

    Haya, Laura; Tavoularis, Stavros

    2015-11-01

    The aortic sinus is approximately tri-radially symmetric, but bileaflet mechanical heart valves (BMHVs), which are commonly used to replace diseased aortic valves, are bilaterally symmetric. This mismatch in symmetry suggests that the orientation in which a BMHV is implanted within the aortic sinus affects the flow characteristics downstream of it. This study examines the effect of BMHV orientation on the flow in the coronary arteries, which originate in the aortic sinus and supply the heart tissue with blood. Planar particle image velocimetry measurements were made past a BMHV mounted at the inlet of an anatomical aorta model under physiological flow conditions. The complex interactions between the valve jets, the sinus vortex and the flow in the right coronary artery were elucidated for three valve orientations. The coronary flow rate was directly affected by the size, orientation, and time evolution of the vortex in the sinus, all of which were sensitive to the valve's orientation. The total flow through the artery was highest when the valve was oriented with its axis of symmetry intersecting the artery's opening. The findings of this research may assist surgeons in choosing the best orientation for BMHV implantation. The bileaflet valve was donated by St. Jude Medical. Financial support was provided by the Natural Sciences and Engineering Research Council of Canada.

  7. Fluid Dynamic Characterization of a Polymeric Heart Valve Prototype (Poli-Valve) tested under Continuous and Pulsatile Flow Conditions

    OpenAIRE

    Gaetano, Francesco De; Serrani, Marta; Bagnoli, Paola; Brubert, Jacob; Stasiak, Joanna; Moggridge, Geoff D.; Costantino, Maria Laura

    2015-01-01

    Purpose Only mechanical and biological heart valve prostheses are currently commercially available. The former show longer durability but require anticoagulant therapy; the latter display better fluid dynamic behavior but do not have adequate durability. New Polymeric Heart Valves (PHVs) could potentially combine the hemodynamic properties of biological valves with the durability of mechanical valves. This work presents a hydrodynamic evaluation of 2 groups of newly developed supra-annula...

  8. Sucrose Diffusion in Decellularized Heart Valves for Freeze-Drying.

    Science.gov (United States)

    Wang, Shangping; Oldenhof, Harriëtte; Goecke, Tobias; Ramm, Robert; Harder, Michael; Haverich, Axel; Hilfiker, Andres; Wolkers, Willem Frederik

    2015-09-01

    Decellularized heart valves can be used as starter matrix implants for heart valve replacement therapies in terms of guided tissue regeneration. Decellularized matrices ideally need to be long-term storable to assure off-the-shelf availability. Freeze-drying is an attractive preservation method, allowing storage at room temperature in a dried state. However, the two inherent processing steps, freezing and drying, can cause severe damage to extracellular matrix (ECM) proteins and the overall tissue histoarchitecture and thus impair biomechanical characteristics of resulting matrices. Freeze-drying therefore requires a lyoprotective agent that stabilizes endogenous structural proteins during both substeps and that forms a protective glassy state at room temperature. To estimate incubation times needed to infiltrate decellularized heart valves with the lyoprotectant sucrose, temperature-dependent diffusion studies were done using Fourier transform infrared spectroscopy. Glycerol, a cryoprotective agent, was studied for comparison. Diffusion of both protectants was found to exhibit Arrhenius behavior. The activation energies of sucrose and glycerol diffusion were found to be 15.9 and 37.7 kJ·mol(-1), respectively. It was estimated that 4 h of incubation at 37°C is sufficient to infiltrate heart valves with sucrose before freeze-drying. Application of a 5% sucrose solution was shown to stabilize acellular valve scaffolds during freeze-drying. Such freeze-dried tissues, however, displayed pores, which were attributed to ice crystal damage, whereas vacuum-dried scaffolds in comparison revealed no pores after drying and rehydration. Exposure to a hygroscopic sucrose solution (80%) before freeze-drying was shown to be an effective method to diminish pore formation in freeze-dried ECMs: matrix structures closely resembled those of control samples that were not freeze-dried. Heart valve matrices were shown to be in a glassy state after drying, suggesting that they can

  9. Understanding Heart Valve Problems and Causes

    Science.gov (United States)

    ... heartbeat with a stethoscope. A murmur may sound like a “whooshing” noise of blood flowing under pressure as it moves from one chamber to the next, or it may sound like an extra click when a valve allows back ...

  10. A novel approach in cross-linking of bioprosthetic heart valves

    NARCIS (Netherlands)

    Everaerts, Fransiscus Joannes Leonardus

    2007-01-01

    Due to some form of heart valve disease, approximately 250000 patients worldwide undergo surgery to receive a new heart-valve each year. In about 70% of the cases a mechanical heart valve is used despite the fact that permanent anticoagulant therapy for the patient is required. The remaining 30% of

  11. Thromboembolism and mechanical heart valves : A randomized study revisited

    NARCIS (Netherlands)

    Kuntze, CEE; Blackstone, EH; Ebels, T

    1998-01-01

    Background. This study was designed to revise and substantiate previous inferences, based on short-term follow-up, about differences in the incidence of anticoagulant-related events after heart valve replacement among patients who had been randomly assigned to receive either a Bjork-Shiley, Edwards-

  12. Heart failure after aortic valve substitution due to severe hypothyroidism

    DEFF Research Database (Denmark)

    Munk, Kim; Sørensen, Stine Heidenheim; Andersen, Niels Holmark;

    2008-01-01

    We report a case of a 70-year-old female with considerable co-morbidities (Type 2 diabetes, Leiden factor V mutation, mild to moderate chronic obstructive pulmonary disease) and a recent biological aortic valve substitution, who was admitted due to circulatory collapse caused by severe heart fail...

  13. MECHANICAL HEART-VALVE PROSTHESES - SOUND LEVEL AND RELATED COMPLAINTS

    NARCIS (Netherlands)

    LAURENS, RRP; WIT, HP; EBELS, T

    1992-01-01

    In a randomised study, we investigated the sound production of mechanical heart valve prostheses and the complaints related to this sound. The CarboMedics, Bjork-Shiley monostrut and StJude Medical prostheses were compared. A-weighted levels of the pulse-like sound produced by the prosthesis were me

  14. Motion analysis of mechanical heart valve prosthesis utilizing high-speed video

    Science.gov (United States)

    Adlparvar, Payam; Guo, George; Kingsbury, Chris

    1993-01-01

    The Edwards-Duromedics (ED) mechanical heart valve prosthesis is of a bileaflet design, incorporating unique design features that distinguish its performance with respect to other mechanical valves of similar type. Leaflet motion of mechanical heart valves, particularly during closure, is related to valve durability, valve sounds and the efficiency of the cardiac output. Modifications to the ED valve have resulted in significant improvements with respect to leaflet motion. In this study a high-speed video system was used to monitor the leaflet motion of the valve, and to compare the performance of the Modified Specification to that of the Original Specification using a St. Jude Medical as a control valve.

  15. Rheumatic heart disease with triple valve involvement

    OpenAIRE

    BRAMBATI, MATTEO; LAURENZI, PIER FRANCESCO; MARLETTA, FIORANGELA; MANINA, GIORGIA; COMINA, DENISE PROVVIDENZA; PRESTON, NGAMBE MANDI; CASSETTI, GIUSEPPINA; MERLO, CHIARA; Volpi, Michele; MUSSO, ROBERTA; LA ROCCA, ROBERTO

    2013-01-01

    Acute rheumatic fever (ARF) is a postinfectious, nonsuppurative sequela of pharyngeal infection caused by Streptococcus pyogenes, or Group A β hemolytic Streptococcus (GABHS). Of the associated symptoms, only damage to the heart’s valvular tissue, or rheumatic heart disease (RHD), can become a chronic condition leading to congestive heart failure, stroke, endocarditis, and death. ARF is the most common cause of cardiac disease in children in developing countries. A joint meeting o...

  16. Pre-clinical In Vitro and In Vivo Models for Heart Valve Therapies.

    Science.gov (United States)

    Taramasso, Maurizio; Emmert, Maximilian Y; Reser, Diana; Guidotti, Andrea; Cesarovic, Nikola; Campagnol, Marino; Addis, Alessandro; Nietlispach, Fabian; Hoerstrup, Simon P; Maisano, Francesco

    2015-07-01

    Heart valve disease is a frequently encountered pathology, related to high morbidity and mortality rates. Animal models are interesting to investigate the causality but also underlying mechanisms and potential treatments of human heart valve diseases. Strongly believing that both in vivo and ex vivo models are fundamental to support research and development of new technologies, we here report some examples of heart valve disease models, which in our experience have been actively used to support the development of new valve therapies.

  17. Transcatheter Pulmonary Valve Replacement by Hybrid Approach Using a Novel Polymeric Prosthetic Heart Valve: Proof of Concept in Sheep

    OpenAIRE

    Ben Zhang; Xiang Chen; Tong-yi Xu; Zhi-gang Zhang; Xin Li; Lin Han; Zhi-yun Xu

    2014-01-01

    Background Since 2000, transcatheter pulmonary valve replacement has steadily advanced. However, the available prosthetic valves are restricted to bioprosthesis which have defects like poor durability. Polymeric heart valve is thought as a promising alternative to bioprosthesis. In this study, we introduced a novel polymeric transcatheter pulmonary valve and evaluated its feasibility and safety in sheep by a hybrid approach. Methods We designed a novel polymeric trileaflet transcatheter pulmo...

  18. Pulmonary heart valve replacement using stabilized acellular xenogeneic scaffolds; effects of seeding with autologous stem cells

    Directory of Open Access Journals (Sweden)

    Harpa Marius Mihai

    2015-12-01

    Full Text Available Background: We hypothesized that an ideal heart valve replacement would be acellular valve root scaffolds seeded with autologous stem cells. To test this hypothesis, we prepared porcine acellular pulmonary valves, seeded them with autologous adipose derived stem cells (ADSCs and implanted them in sheep and compared them to acellular valves.

  19. Micro and nanotechnologies in heart valve tissue engineering.

    Science.gov (United States)

    Hasan, Anwarul; Saliba, John; Pezeshgi Modarres, Hassan; Bakhaty, Ahmed; Nasajpour, Amir; Mofrad, Mohammad R K; Sanati-Nezhad, Amir

    2016-10-01

    Due to the increased morbidity and mortality resulting from heart valve diseases, there is a growing demand for off-the-shelf implantable tissue engineered heart valves (TEHVs). Despite the significant progress in recent years in improving the design and performance of TEHV constructs, viable and functional human implantable TEHV constructs have remained elusive. The recent advances in micro and nanoscale technologies including the microfabrication, nano-microfiber based scaffolds preparation, 3D cell encapsulated hydrogels preparation, microfluidic, micro-bioreactors, nano-microscale biosensors as well as the computational methods and models for simulation of biological tissues have increased the potential for realizing viable, functional and implantable TEHV constructs. In this review, we aim to present an overview of the importance and recent advances in micro and nano-scale technologies for the development of TEHV constructs. PMID:27414719

  20. Stabilized Collagen Scaffolds for Heart Valve Tissue Engineering

    OpenAIRE

    Tedder, Mary E.; Liao, Jun; Weed, Benjamin; Stabler, Christopher; Zhang, Henry; Simionescu, Agneta; Simionescu, Dan T.

    2008-01-01

    Scaffolds for heart valve tissue engineering must function immediately after implantation but also need to tolerate cell infiltration and gradual remodeling. We hypothesized that moderately cross-linked collagen scaffolds would fulfill these requirements. To test our hypothesis, scaffolds prepared from decellularized porcine pericardium were treated with penta-galloyl glucose (PGG), a collagen-binding polyphenol, and tested for biodegradation, biaxial mechanical properties, and in vivo biocom...

  1. Glutaraldehyde exposures among workers making bioprosthetic heart valves.

    Science.gov (United States)

    Sutton, Patrice M; Quint, Julia; Prudhomme, Janice; Flattery, Jennifer; Materna, Barbara; Harrison, Robert

    2007-05-01

    Exposure to glutaraldehyde is a recognized cause of work-related asthma. An investigation was undertaken to describe exposure to glutaraldehyde among workers making bioprosthetic heart valves and to make recommendations for prevention. At the two largest heart valve manufacturing facilities in California, the work process was observed; employer representatives and glutaraldehyde-exposed workers were interviewed; and employer written records, including company-generated industrial hygiene data, were analyzed. Approximately 600 female workers had continuous airborne exposure to glutaraldehyde over the course of every work shift and the routine potential for skin and eye contact with glutaraldehyde while making heart valves. Employee short-term (15-min) glutaraldehyde exposures were all well below the current regulatory ceiling level (0.20 ppm). Overall, approximately 40% of the glutaraldehyde-related job tasks involved exposures above the American Conference of Industrial Hygienists threshold limit value ceiling of 0.05 ppm; the majority (71.4% and 83.3%, depending on the company) involved exposures greater than 0.015 ppm. At one company, two cases of physician-diagnosed asthma were recorded by the employer in the previous 5-year period; these reports met the surveillance case definition for new-onset, work-related asthma associated with a known asthma inducer. Factors that contributed to worker exposure included large exposed surface areas of glutaraldehyde under agitation; working with glutaraldehyde-treated tissue in proximity to workers' breathing zones; manual pouring and disposal of glutaraldehyde solutions without local exhaust ventilation, eye protection, and waste neutralization; and prolonged use of latex gloves. Workers making bioprosthetic heart valves are at risk for occupationally acquired asthma. Employers should implement additional engineering controls to minimize workers' exposures to at least below a level of 0.015 ppm, an appropriate glove to

  2. Genetic regulation of heart valve development: Clinical implications

    Directory of Open Access Journals (Sweden)

    Marc-Phillip Hitz

    2011-12-01

    Full Text Available Cardiac malformations, most commonly valve defects, are some of the predominant causes of cardiovascular morbidity and mortality worldwide. Up to a third of all patients with complex congenital heart defects and numerous syndromic conditions, as well as a significant amount of the general population, exhibit valve defects. These observations have not only major implications in infancy; they also have a major impact on the adult population and the growing number of adults with congenital malformations. Over recent years, a large number of Mendelian inheritance patterns and syndromic causes have been identified, shedding light on the importance of genes encoding components of the extracelluar matrix in valve disease. Nevertheless, we still know little about the genetic origin of sporadic and more complex family traits. It is unclear to what extent genetic variations play a role in disease pathogenesis and influences phenotypes rooted in early development. Such knowledge would be greatly beneficial for counseling and treatment of patients. Therefore, this review summarizes the findings in human non-syndromic and syndromic valve disease with a special focus on extracellular matrix proteins, and discusses them in the context of vertebrate valve development.

  3. Stabilized collagen scaffolds for heart valve tissue engineering.

    Science.gov (United States)

    Tedder, Mary E; Liao, Jun; Weed, Benjamin; Stabler, Christopher; Zhang, Henry; Simionescu, Agneta; Simionescu, Dan T

    2009-06-01

    Scaffolds for heart valve tissue engineering must function immediately after implantation but also need to tolerate cell infiltration and gradual remodeling. We hypothesized that moderately cross-linked collagen scaffolds would fulfill these requirements. To test our hypothesis, scaffolds prepared from decellularized porcine pericardium were treated with penta-galloyl glucose (PGG), a collagen-binding polyphenol, and tested for biodegradation, biaxial mechanical properties, and in vivo biocompatibility. For controls, we used un-cross-linked scaffolds and glutaraldehyde-treated scaffolds. Results confirmed complete pericardium decellularization and the ability of scaffolds to encourage fibroblast chemotaxis and to aid in creation of anatomically correct valve-shaped constructs. Glutaraldehyde cross-linking fully stabilized collagen but did not allow for tissue remodeling and calcified when implanted subdermally in rats. PGG-treated collagen was initially resistant to collagenase and then degraded gradually, indicating partial stabilization. Moreover, PGG-treated pericardium exhibited excellent biaxial mechanical properties, did not calcify in vivo, and supported infiltration by host fibroblasts and subsequent matrix remodeling. In conclusion, PGG-treated acellular pericardium is a promising scaffold for heart valve tissue engineering. PMID:18928400

  4. Computational Simulation of Blood Flow through Bileaflet Heart Valve Prostheses

    Science.gov (United States)

    Healy, Timothy; Sotiropoulos, Fotis; Yoganathan, Ajit

    2001-11-01

    Non-physiologic flow patterns and levels of turbulence caused by contemporary bileaflet mechanical heart valve (MHV) designs are believed to be partially responsible for thromboembolic complications caused by these valves. Presently, computer-based flow assessment is not employed as a design tool. Rather, CFD is used to understand flow dynamics under highly-specialized circumstances after a design has been selected and tested experimentally. The absence of CFD from the design-screening process is most likely due to undeveloped tools specific to the heart valve problem. CFD tools for assessing MHV flow performance should be efficient at simulating the fluid-structure interaction and the resulting leaflet motion. As the first stage in the development of MHV simulation tools, a high-accuracy Chimera solver was developed and tested for laminar flow through two bileaflet MHV designs. Steady and time-dependent simulations were performed providing the highest resolution simulations of three-dimensional MHV flow fields to date. Flow structures and time-dependent flow phenomena were investigated and interpreted in the context of the clinical performance of each design studied.

  5. Dynamic heart phantom with functional mitral and aortic valves

    Science.gov (United States)

    Vannelli, Claire; Moore, John; McLeod, Jonathan; Ceh, Dennis; Peters, Terry

    2015-03-01

    Cardiac valvular stenosis, prolapse and regurgitation are increasingly common conditions, particularly in an elderly population with limited potential for on-pump cardiac surgery. NeoChord©, MitraClipand numerous stent-based transcatheter aortic valve implantation (TAVI) devices provide an alternative to intrusive cardiac operations; performed while the heart is beating, these procedures require surgeons and cardiologists to learn new image-guidance based techniques. Developing these visual aids and protocols is a challenging task that benefits from sophisticated simulators. Existing models lack features needed to simulate off-pump valvular procedures: functional, dynamic valves, apical and vascular access, and user flexibility for different activation patterns such as variable heart rates and rapid pacing. We present a left ventricle phantom with these characteristics. The phantom can be used to simulate valvular repair and replacement procedures with magnetic tracking, augmented reality, fluoroscopy and ultrasound guidance. This tool serves as a platform to develop image-guidance and image processing techniques required for a range of minimally invasive cardiac interventions. The phantom mimics in vivo mitral and aortic valve motion, permitting realistic ultrasound images of these components to be acquired. It also has a physiological realistic left ventricular ejection fraction of 50%. Given its realistic imaging properties and non-biodegradable composition—silicone for tissue, water for blood—the system promises to reduce the number of animal trials required to develop image guidance applications for valvular repair and replacement. The phantom has been used in validation studies for both TAVI image-guidance techniques1, and image-based mitral valve tracking algorithms2.

  6. [History, present and future of biomaterials used for artificial heart valves].

    Science.gov (United States)

    Kostrzewa, Benita; Rybak, Zbigniew

    2013-01-01

    Artificial heart valves can be classified into mechanical and biological. We have three types of mechanical heart valves: caged ball, tilting disc and bileaflet. Mechanical heart valves are made from various materials. They may be produced from metals, ceramics and polymers, e.g.: stainless steel, titanium, silicone, pyrolytic carbon. Biological valves are made from synthetic components (e.g.: PTFE, Dacron) and materials of biological origin (e.g.: cow pericardium, pig heart valve). We have also identified transcatheter aortic valve implantation (TAVI). TAVI may be produced from metals, ceramics and polymers (e.g.: stainless steel, titanium, Dacron) and biological material (e.g.: pig heart valve). This paper describes advantages and disadvantages of different types of artificial heart valves. The lifespan of mechanical valves is 20-30 years and they can be used for patients of any age. Mechanical valves have also disadvantages--anticoagulants are required to prevent thrombosis. Biological valves are made from natural materials, so they do not require prolonged anticoagulation. Their lifetime is 10-15 years, so they are offered to patients over 40 years. Another problem is the occurrence of calcification.

  7. Effects of valve geometry and tissue anisotropy on the radial stretch and coaptation area of tissue-engineered heart valves.

    Science.gov (United States)

    Loerakker, S; Argento, G; Oomens, C W J; Baaijens, F P T

    2013-07-26

    Tissue engineering represents a promising technique to overcome the limitations of the current valve replacements, since it allows for creating living autologous heart valves that have the potential to grow and remodel. However, also this approach still faces a number of challenges. One particular problem is regurgitation, caused by cell-mediated tissue retraction or the mismatch in geometrical and material properties between tissue-engineered heart valves (TEHVs) and their native counterparts. The goal of the present study was to assess the influence of valve geometry and tissue anisotropy on the deformation profile and closed configuration of TEHVs. To achieve this aim, a range of finite element models incorporating different valve shapes was developed, and the constitutive behavior of the tissue was modeled using an established computational framework, where the degree of anisotropy was varied between values representative of TEHVs and native valves. The results of this study suggest that valve geometry and tissue anisotropy are both important to maximize the radial strains and thereby the coaptation area. Additionally, the minimum degree of anisotropy that is required to obtain positive radial strains was shown to depend on the valve shape and the pressure to which the valves are exposed. Exposure to pulmonary diastolic pressure only yielded positive radial strains if the anisotropy was comparable to the native situation, whereas considerably less anisotropy was required if the valves were exposed to aortic diastolic pressure.

  8. Tgfβ-Smad and MAPK signaling mediate scleraxis and proteoglycan expression in heart valves.

    Science.gov (United States)

    Barnette, Damien N; Hulin, Alexia; Ahmed, A S Ishtiaq; Colige, Alain C; Azhar, Mohamad; Lincoln, Joy

    2013-12-01

    Mature heart valves are complex structures consisting of three highly organized extracellular matrix layers primarily composed of collagens, proteoglycans and elastin. Collectively, these diverse matrix components provide all the necessary biomechanical properties for valve function throughout life. In contrast to healthy valves, myxomatous valve disease is the most common cause of mitral valve prolapse in the human population and is characterized by an abnormal abundance of proteoglycans within the valve tri-laminar structure. Despite the clinical significance, the etiology of this phenotype is not known. Scleraxis (Scx) is a basic-helix-loop-helix transcription factor that we previously showed to be required for establishing heart valve structure during remodeling stages of valvulogenesis. In this study, we report that remodeling heart valves from Scx null mice express decreased levels of proteoglycans, particularly chondroitin sulfate proteoglycans (CSPGs), while overexpression in embryonic avian valve precursor cells and adult porcine valve interstitial cells increases CSPGs. Using these systems we further identify that Scx is positively regulated by canonical Tgfβ2 signaling during this process and this is attenuated by MAPK activity. Finally, we show that Scx is increased in myxomatous valves from human patients and mouse models, and overexpression in human mitral valve interstitial cells modestly increases proteoglycan expression consistent with myxomatous mitral valve phenotypes. Together, these studies identify an important role for Scx in regulating proteoglycans in embryonic and mature valve cells and suggest that imbalanced regulation could influence myxomatous pathogenesis.

  9. Artifact reduction strategies for prosthetic heart valve CT imaging

    OpenAIRE

    Habets, Jesse; Symersky, Petr; Leiner, Tim; de Mol, Bas A. J. M.; Willem P Th M Mali; Budde, Ricardo P.J.

    2012-01-01

    Multislice CT evaluation of prosthetic heart valves (PHV) is limited by PHV-related artifacts. We assessed the influence of different kV settings, a metal artifact reduction filter (MARF) and an iterative reconstruction algorithm (IR) on PHV-induced artifacts in an in vitro model. A Medtronic-Hall tilting disc and St Jude bileafet PHV were imaged using a 64-slice scanner with 100 kV/165 mAs, 120 kV/100 mAs, 140 kV/67 mAs at an equal CTDIvol. Images were reconstructed with (1) filtered back pr...

  10. PIV validation of blood-heart valve leaflet interaction modelling.

    Science.gov (United States)

    Kaminsky, R; Dumont, K; Weber, H; Schroll, M; Verdonck, P

    2007-07-01

    The aim of this study was to validate the 2D computational fluid dynamics (CFD) results of a moving heart valve based on a fluid-structure interaction (FSI) algorithm with experimental measurements. Firstly, a pulsatile laminar flow through a monoleaflet valve model with a stiff leaflet was visualized by means of Particle Image Velocimetry (PIV). The inflow data sets were applied to a CFD simulation including blood-leaflet interaction. The measurement section with a fixed leaflet was enclosed into a standard mock loop in series with a Harvard Apparatus Pulsatile Blood Pump, a compliance chamber and a reservoir. Standard 2D PIV measurements were made at a frequency of 60 bpm. Average velocity magnitude results of 36 phase-locked measurements were evaluated at every 10 degrees of the pump cycle. For the CFD flow simulation, a commercially available package from Fluent Inc. was used in combination with inhouse developed FSI code based on the Arbitrary Lagrangian-Eulerian (ALE) method. Then the CFD code was applied to the leaflet to quantify the shear stress on it. Generally, the CFD results are in agreement with the PIV evaluated data in major flow regions, thereby validating the FSI simulation of a monoleaflet valve with a flexible leaflet. The applicability of the new CFD code for quantifying the shear stress on a flexible leaflet is thus demonstrated.

  11. Patient experiences of recovery after heart valve replacement: suffering weakness, struggling to resume normality

    DEFF Research Database (Denmark)

    Berg, Selina Kikkenborg; Zwisler, Ann-Dorthe; Pedersen, Birthe D.;

    2013-01-01

    Heart valve disease is becoming a public health problem due to increasing life expectancy and new treatment methods. Patients are at risk of developing depression, anxiety or post-traumatic stress disorder after heart valve surgery. To better plan proper care, describing and understanding patients...

  12. Consecutive percutaneous valve-in-valve replacement late after Ross procedure: A novel approach in an adult with congenital heart disease.

    Science.gov (United States)

    Wiktor, Dominik M; Kay, Joseph D; Kim, Michael S

    2015-11-15

    The emergence of transcatheter valve technology over the last decade has made significant impact on the treatment of patients with valvular heart disease. There has been increasing experience with both native and valve-in-valve indications with promising results. We present the case of a young woman with congenital heart disease who underwent the Ross procedure for bicuspid aortic valve endocarditis with subsequent reoperation and surgical aortic valve replacement for neo-aortic root dilation who experienced worsening symptoms related to both pulmonary and aortic valve dysfunction. She was successfully treated with percutaneous pulmonary and aortic valve replacement with excellent early term technical results and marked improvement in symptoms.

  13. In vivo tissue engineering of heart valves: evolution of a novel concept.

    Science.gov (United States)

    Schleicher, Martina; Wendel, Hans Peter; Fritze, Olaf; Stock, Ulrich A

    2009-07-01

    Current tissue-engineering principles of heart valves include tissue- or stem cell-derived cells with subsequent in vitro incubation on various scaffolds prior to implantation. Limitations of this approach include a long in vitro culture, an accompanied risk of infection and sophisticated, cost-intensive infrastructures. An 'off-the-shelf' heart valve with in vivo endothelialization and tissue-regeneration potential would overcome these limitations. Additionally, the development of a heart valve with growth potential would be a huge improvement for pediatric patients. This article discusses different starter matrices, homing and immobilization strategies of host cells and masking approaches of inflammatory structures for in vivo surface and tissue engineering of heart valves. Novel concepts will be presented based on highly specific DNA-aptamers immobilized on the heart valve surface as capture molecules for endothelial progenitor cells circulating in the bloodstream.

  14. Application of stereolithography for scaffold fabrication for tissue engineered heart valves.

    Science.gov (United States)

    Sodian, Ralf; Loebe, Matthias; Hein, Andreas; Martin, David P; Hoerstrup, Simon P; Potapov, Evgenij V; Hausmann, Harald; Lueth, Tim; Hetzer, Roland

    2002-01-01

    A crucial factor in tissue engineering of heart valves is the functional and physiologic scaffold design. In our current experiment, we describe a new fabrication technique for heart valve scaffolds, derived from x-ray computed tomography data linked to the rapid prototyping technique of stereolithography. To recreate the complex anatomic structure of a human pulmonary and aortic homograft, we have used stereolithographic models derived from x-ray computed tomography and specific software (CP, Aachen, Germany). These stereolithographic models were used to generate biocompatible and biodegradable heart valve scaffolds by a thermal processing technique. The scaffold forming polymer was a thermoplastic elastomer, a poly-4-hydroxybutyrate (P4HB) and a polyhydroxyoctanoate (PHOH) (Tepha, Inc., Cambridge, MA). We fabricated one human aortic root scaffold and one pulmonary heart valve scaffold. Analysis of the heart valve included functional testing in a pulsatile bioreactor under subphysiological and supraphysiological flow and pressure conditions. Using stereolithography, we were able to fabricate plastic models with accurate anatomy of a human valvular homograft. Moreover, we fabricated heart valve scaffolds with a physiologic valve design, which included the sinus of Valsalva, and that resembled our reconstructed aortic root and pulmonary valve. One advantage of P4HB and PHOH was the ability to mold a complete trileaflet heart valve scaffold from a stereolithographic model without the need for suturing. The heart valves were tested in a pulsatile bioreactor, and it was noted that the leaflets opened and closed synchronously under subphysiological and supraphysiological flow conditions. Our preliminary results suggest that the reproduction of complex anatomic structures by rapid prototyping techniques may be useful to fabricate custom made polymeric scaffolds for the tissue engineering of heart valves.

  15. In vitro hemodynamics and valve imaging in passive beating hearts.

    Science.gov (United States)

    Leopaldi, A M; Vismara, R; Lemma, M; Valerio, L; Cervo, M; Mangini, A; Contino, M; Redaelli, A; Antona, C; Fiore, G B

    2012-04-30

    Due to their high complexity, surgical approaches to valve repair may benefit from the use of in vitro simulators both for training and for the investigation of those measures which can lead to better clinical results. In vitro tests are intrinsically more effective when all the anatomical substructures of the valvular complexes are preserved. In this work, a mock apparatus able to house an entire explanted porcine heart and subject it to pulsatile fluid-dynamic conditions was developed, in order to enable the hemodynamic analysis of simulated surgical procedures and the imaging of the valvular structures. The mock loop's hydrodynamic design was based on an ad-hoc defined lumped-parameter model. The left ventricle of an entire swine heart was dynamically pressurized by an external computer-controlled pulse duplicator. The ascending aorta was connected to a hydraulic circuit which simulated the input impedance of the systemic circulation; a reservoir passively filled the left atrium. Accesses for endoscopic imaging were located in the apex of the left ventricle and in the aortic root. The experimental pressure and flow tracings were comparable with the typical in vivo curves; a mean flow of 3.5±0.1l pm and a mean arterial pressure of 101±2 mmHg was obtained. High-quality echographic and endoscopic video recordings demonstrated the system's excellent potential in the observation of the cardiac structures dynamics. The proposed mock loop represents a suitable in vitro system for the testing of minimally-invasive cardiovascular devices and surgical procedures for heart valve repair. PMID:22387122

  16. Heart rate and heart rate variability in dogs with different degrees of myxomatous mitral valve disease

    DEFF Research Database (Denmark)

    Rasmussen, Caroline Elisabeth; Falk, Bo Torkel; Zois, Nora Elisabeth;

    2011-01-01

    moderate/severe MR and in HF compared to CKCS with no/minimal and mild MR (all P<0.02). Another 10 HRV variables showed the same groupwise differences (all P<0.02), except that the difference between CKCS with mild MR and CKCS with moderate/severe MR did not reach statistical significance. Minimum HR, mean......HEART RATE AND HEART RATE VARIABILITY IN DOGS WITH DIFFERENT DEGREES OF MYXOMATOUS MITRAL VALVE DISEASE. CE Rasmussen1, T Falk1, NE Zois1, SG Moesgaard1, HD Pedersen2, J Häggström3 and LH Olsen1. 1. Department of Basic Animal and Veterinary Sciences, Faculty of Life Sciences, University of...... Copenhagen, Frederiksberg, Denmark. 2. Novo Nordic A/S, Maaloev, Denmark. 3. Department of Clinical Sciences, Swedish University of Agricultural Science, Uppsala, Sweden. Heart rate variability (HRV) is an indirect measurement of the autonomic modulation of heart rate (HR). Reduced HRV measured from short...

  17. Valve Disease

    Science.gov (United States)

    ... Myocarditis Obstructive Sleep Apnea Pericarditis Peripheral Vascular Disease Rheumatic Fever Sick Sinus Syndrome Silent Ischemia Stroke Sudden Cardiac Arrest Vulnerable Plaque Valve Disease | Share Related terms: heart valves, valve insufficiency, valve regurgitation, valve stenosis, valvular ...

  18. Reynolds shear stress for textile prosthetic heart valves in relation to fabric design.

    Science.gov (United States)

    Bark, David L; Yousefi, Atieh; Forleo, Marcio; Vaesken, Antoine; Heim, Frederic; Dasi, Lakshmi P

    2016-07-01

    The most widely implanted prosthetic heart valves are either mechanical or bioprosthetic. While the former suffers from thrombotic risks, the latter suffers from a lack of durability. Textile valves, alternatively, can be designed with durability and to exhibit hemodynamics similar to the native valve, lowering the risk for thrombosis. Deviations from native valve hemodynamics can result in an increased Reynolds Shear Stress (RSS), which has the potential to instigate hemolysis or shear-induced thrombosis. This study is aimed at characterizing flow in multiple textile valve designs with an aim of developing a low profile valve. Valves were created using a shaping process based on heating a textile membrane and placed within a left heart simulator. Turbulence and bulk hemodynamics were assessed through particle imaging velocimetry, along with flow and pressure measurements. Overall, RSS was reduced for low profile valves relative to high profile valves, but was otherwise similar among low profile valves involving different fabric designs. However, leakage was found in 3 of the 4 low profile valve designs driving the fabric design for low profile valves. Through textile design, low profile valves can be created with favorable hemodynamics. PMID:26919564

  19. Reynolds shear stress for textile prosthetic heart valves in relation to fabric design.

    Science.gov (United States)

    Bark, David L; Yousefi, Atieh; Forleo, Marcio; Vaesken, Antoine; Heim, Frederic; Dasi, Lakshmi P

    2016-07-01

    The most widely implanted prosthetic heart valves are either mechanical or bioprosthetic. While the former suffers from thrombotic risks, the latter suffers from a lack of durability. Textile valves, alternatively, can be designed with durability and to exhibit hemodynamics similar to the native valve, lowering the risk for thrombosis. Deviations from native valve hemodynamics can result in an increased Reynolds Shear Stress (RSS), which has the potential to instigate hemolysis or shear-induced thrombosis. This study is aimed at characterizing flow in multiple textile valve designs with an aim of developing a low profile valve. Valves were created using a shaping process based on heating a textile membrane and placed within a left heart simulator. Turbulence and bulk hemodynamics were assessed through particle imaging velocimetry, along with flow and pressure measurements. Overall, RSS was reduced for low profile valves relative to high profile valves, but was otherwise similar among low profile valves involving different fabric designs. However, leakage was found in 3 of the 4 low profile valve designs driving the fabric design for low profile valves. Through textile design, low profile valves can be created with favorable hemodynamics.

  20. Pregnancy with prosthetic heart valves - 30 years' nationwide experience in Denmark

    DEFF Research Database (Denmark)

    Sillesen, Martin; Hjortdal, Vibeke; Vejlstrup, Niels;

    2011-01-01

    Pregnancy in women with prosthetic heart valves remains a risk factor for both mother and fetus, but unselected and unbiased outcome and complication data remain scarce. We analyzed nationwide outcome data from 1977 to 2007 for all pregnancies in women with prosthetic valves.......Pregnancy in women with prosthetic heart valves remains a risk factor for both mother and fetus, but unselected and unbiased outcome and complication data remain scarce. We analyzed nationwide outcome data from 1977 to 2007 for all pregnancies in women with prosthetic valves....

  1. Transcatheter pulmonary valve replacement by hybrid approach using a novel polymeric prosthetic heart valve: proof of concept in sheep.

    Directory of Open Access Journals (Sweden)

    Ben Zhang

    Full Text Available Since 2000, transcatheter pulmonary valve replacement has steadily advanced. However, the available prosthetic valves are restricted to bioprosthesis which have defects like poor durability. Polymeric heart valve is thought as a promising alternative to bioprosthesis. In this study, we introduced a novel polymeric transcatheter pulmonary valve and evaluated its feasibility and safety in sheep by a hybrid approach.We designed a novel polymeric trileaflet transcatheter pulmonary valve with a balloon-expandable stent, and the valve leaflets were made of 0.1-mm expanded polytetrafluoroethylene (ePTFE coated with phosphorylcholine. We chose glutaraldehyde-treated bovine pericardium valves as control. Pulmonary valve stents were implanted in situ by a hybrid transapical approach in 10 healthy sheep (8 for polymeric valve and 2 for bovine pericardium valve, weighing an average of 22.5±2.0 kg. Angiography and cardiac catheter examination were performed after implantation to assess immediate valvular functionality. After 4-week follow-up, angiography, echocardiography, computed tomography, and cardiac catheter examination were used to assess early valvular function. One randomly selected sheep with polymeric valve was euthanized and the explanted valved stent was analyzed macroscopically and microscopically.Implantation was successful in 9 sheep. Angiography at implantation showed all 9 prosthetic valves demonstrated orthotopic position and normal functionality. All 9 sheep survived at 4-week follow-up. Four-week follow-up revealed no evidence of valve stent dislocation or deformation and normal valvular and cardiac functionality. The cardiac catheter examination showed the peak-peak transvalvular pressure gradient of the polymeric valves was 11.9±5.0 mmHg, while that of two bovine pericardium valves were 11 and 17 mmHg. Gross morphology demonstrated good opening and closure characteristics. No thrombus or calcification was seen macroscopically

  2. On the open/close performance of prosthetic heart valves at high frequencies

    Science.gov (United States)

    Beltran, A.; Zenit, R.

    2013-11-01

    We report experimental observations of the performance of mechanical and biological prosthetic heart valves. The valves are mounted in a test circular channel conected to a flow system that emulates accelerated human-like conditions. The flow is generated by a high frequencie pulsative pump (in the range of 7 to 18 Hz). The objective of the investigation is to find the treshold conditions for which the open/close performance fails. Preliminary results show that for the mechanical valve the failure starts at 436 pulses/min, while for the biological valve, it starts a failing performance is observed for frequencies higher that 462 pulses/min. Even though these values are far from the heart rate in the human body, we use these measurements to further understand the structure-fluid interaction mechanics of the flow through heart valves.

  3. Risk factors for rejection for morphological reasons of heart valves for transplantation.

    Science.gov (United States)

    van Wijk, Marja J; van den Bogaerdt, Antoon; Bokhorst, Arlinke G

    2013-03-01

    The study aim was to identify risk factors for morphological rejection of aortic and pulmonary valves for transplantation that could be used to optimize donor selection. The files of all Dutch heart valve donors, donating in a 2.5 years period, whose hearts were processed at Heart Valve Bank Rotterdam, were reviewed for all factors that could be relevant for valve rejection and related to outcome of morphological assessment of the valves. Valves were retrieved from 813 deceased Dutch donors, 24.1% also donating organs. For 797 aortic and 767 pulmonary valves, who met retrieval criteria, morphological assessment was done. 69.5% of aortic and 37.5% of pulmonary valves were considered unsuitable for transplantation at morphological assessment. Backward stepwise multivariate logistic regression analysis, showed age, cardiac cause of death, cerebrovascular accident as cause of death or in medical history, and number of cardiovascular risk factors in a donor to be independent risk factors for morphological rejection of aortic valves. Age, sex, weight >100 kg and ruptured aortic aneurysm as cause of death were independent risk factors for morphological rejection of pulmonary valves. Being an organ donor was an independent predictor of morphological approval of aortic and pulmonary valves, while hypertension was an independent predictor for morphological approval of aortic valves. Thus, independent factors were identified that are associated with morphological rejection of aortic and pulmonary valves for transplantation, and that could be used to optimize donor selection by preventing unnecessary retrievals, limiting costs, while improving yield per donor with minimal compromise for availability.

  4. Experience in procurement and processing of heart valves at the Northwest Tissue Center

    International Nuclear Information System (INIS)

    The Northwest Tissue Center established a human heart valve program in 199 1. It is one of four non-profit tissue banks and one for-profit program that recover and process heart valves in the United States. During the eight years in which the Northwest Tissue Center has been involved in heart valve banking, there have been a total of 673 hearts procured for processing. The age of the donors ranged from <1 to 44 years with a mean of 26.2 years, 66% werw male,and 6.5% of the hearts procered were discarded due to a variety of medical and criteria reason. The primary reasons for differal were questions of possible cancer and questions of high risk behavior/social history. Of the 1,264 cardiovascular tissues processed, 6% were lost because of donor history, 17% were lost because of microbiology results, and 5% were lost because of donor serology . There were total a total of 190 aortic valves and 48 pulmonic conduits transplanted over this time period. The mean age of the recipients was 23.4 with a median or 23 years; 102 of the recipients were less than one year of age. Males comprised 62% of the recipients. Since 1993, there has been a clear shift towards more use of pulmonic valves over aortic valves as a results of the acceptance of the Ross procedure. Early in the program, reports were received from surgeons that some heart valves appeared to have cracks in the conduits. Experimentations in the laboratory led to the discovery that thawing too rapidly would result in cracking of these materials. Packaging was designed to reduce the rate of thawing and this has resolved the problem with cracking. The heart valve program at the Northwest Tissue Center has been very successful in providing the necessary valves for patients in the Northwest Region of the United States

  5. Coronary artery assessment by multidetector computed tomography in patients with prosthetic heart valves

    NARCIS (Netherlands)

    Habets, Jesse; van den Brink, Renee B. A.; Uijlings, Ruben; Spijkerboer, Anje M.; Mali, Willem P. Th. M.; Chamuleau, Steven A. J.; Budde, Ricardo P. J.

    2012-01-01

    Objectives Patients with prosthetic heart valves may require assessment for coronary artery disease. We assessed whether valve artefacts hamper coronary artery assessment by multidetector CT. Methods ECG-gated or -triggered CT angiograms were selected from our PACS archive based on the presence of p

  6. Fluid dynamics of heart valves during atrial fibrillation: a lumped parameter-based approach.

    Science.gov (United States)

    Scarsoglio, S; Camporeale, C; Guala, A; Ridolfi, L

    2016-08-01

    Atrial fibrillation (AF) consequences on the heart valve dynamics are usually studied along with a valvular disfunction or disease, since in medical monitoring, the two pathologies are often concomitant. Aim of the present work is to study, through a stochastic lumped-parameter approach, the basic fluid dynamics variations of heart valves, when only paroxysmal AF is present with respect to the normal sinus rhythm in absence of any valvular pathology. Among the most common parameters interpreting the valvular function, the most useful turns out to be the regurgitant volume. During AF, both atrial valves do not seem to worsen their performance, while the ventricular efficiency is remarkably reduced. PMID:26460925

  7. Fluid dynamics of heart valves during atrial fibrillation: a lumped parameter-based approach

    CERN Document Server

    Scarsoglio, Stefania; Guala, Andrea; Ridolfi, Luca

    2015-01-01

    Atrial fibrillation (AF) consequences on the heart valve dynamics are usually studied along with a valvular disfunction or disease, since in medical monitoring the two pathologies are often concomitant. Aim of the present work is to study, through a stochastic lumped-parameter approach, the basic fluid dynamics variations of heart valves, when only paroxysmal AF is present with respect to the normal sinus rhythm (NSR) in absence of any valvular pathology. Among the most common parameters interpreting the valvular function, the most useful turns out to be the regurgitant volume. During AF both atrial valves do not seem to worsen their performance, while the ventricular efficiency is remarkably reduced.

  8. Neomycin and carbodiimide crosslinking as an alternative to glutaraldehyde for enhanced durability of bioprosthetic heart valves.

    Science.gov (United States)

    Leong, Joshua; Munnelly, Amy; Liberio, Brianna; Cochrane, Leonard; Vyavahare, Naren

    2013-05-01

    Glutaraldehyde cross-linked porcine aortic valves, referred to as bioprosthetic heart valves (BHVs), are often used in heart valve replacements. Glutaraldehyde does not stabilize glycosaminoglycans (GAGs) and they are lost during preparation, in vivo implantation, cyclic fatigue, and storage. We report that binding of neomycin, a hyaluronidase inhibitor, to the tissues with carbodiimide cross-linking improves GAG retention without reducing collagen and elastin stability. It also led to improved biomechanical properties. Neomycin carbodiimide cross-linking did not significantly reduce calcification in a rat subdermal implantation model when they were stored in formaldehyde after cross-linking. Removal of formaldehyde storage significantly reduced calcification.

  9. Mitral valve operations at a high-volume pediatric heart center: Evolving techniques and improved survival with mitral valve repair versus replacement

    Directory of Open Access Journals (Sweden)

    Christopher W Baird

    2012-01-01

    Full Text Available Mitral valve disease is quite variable and can occur as an isolated defect or in association with other complex left sided lesions. These lesions are often best described with detailed pre-operative imaging studies to define the valve anatomy and to access associated left heart disease. Depending on the type of mitral valve disease, various surgical repair techniques have led to improved survival in the recent era. We describe lesion specific approach to mitral valve repair and results.

  10. Outcome of left heart mechanical valve replacement in West African children - A 15-year retrospective study

    Directory of Open Access Journals (Sweden)

    Tamatey Martin

    2011-04-01

    Full Text Available Abstract Background The West African sub-region has poor health infrastructure. Mechanical valve replacement in children from such regions raises important postoperative concerns; among these, valve-related morbidity and complications of lifelong anticoagulation are foremost. Little is known about the long-term outcome of mechanical valve replacement in West Africa. We sought to determine the outcome of mechanical valve replacement of the left heart in children from this sub-region. Method We conducted a retrospective review of all consecutive left heart valve replacements in children ( Results One hundred and fourteen patients underwent mitral valve replacement (MVR, aortic valve replacement (AVR or mitral and aortic valve replacements (MAVR. Their ages ranged from 6-18 years (13.3 ± 3.1 years. All patients were in NYHA class III or IV. Median follow up was 9.1 years. MVR was performed in 91 (79.8% patients, AVR in 13 (11.4% and MAVR in 10 (8.8% patients. Tricuspid valve repair was performed concomitantly in 45 (39.5% patients. There were 6 (5.3% early deaths and 6 (5.3% late deaths. Preoperative left ventricular dysfunction (ejection fraction Conclusion Mechanical valve replacement in West African children has excellent outcomes in terms of mortality, valve-related events, and reoperation rate. Preoperative left ventricular dysfunction is the primary determinant of mortality within the first 2 years of valve replacement. The risk of valve-related complications is acceptably low. Anticoagulation is well tolerated with a very low risk of bleeding even in this socioeconomic setting.

  11. Cinematics and sticking of heart valves in pulsatile flow test.

    Science.gov (United States)

    Köhler, J; Wirtz, R

    1991-05-01

    The aim of the project was to develop laboratory test devices for studies of the cinematics and sticking behaviour of technical valve protheses. The second step includes testing technical valves of different types and sizes under static and dynamic conditions. A force-deflection balance was developed in order to load valve rims by static radial forces until sticking or loss of a disc (sticking- and clamping-mould point) with computer-controlled force deflection curves. A second deflection device was developed and used for prosthetic valves in the aortic position of a pulsatile mock circulation loop with simultaneous video-cinematography. The stiffness of technical valve rims varied between 0.20 (St. Jude) and about 1.0 N/micron (metal rim valves). The stiffness decreased significantly with increasing valve size. Sticking under pulsatile flow conditions was in good agreement with the static deflection measurements. Hence, valve sticking with increasing danger of thrombus formation is more likely with a less stiff valve rim. In the case of forces acting perpendicularly to the pendulum axis, the clamping mould-point of the valve can be reached, followed by disc dislodgement. PMID:1864654

  12. Galnt1 is required for normal heart valve development and cardiac function.

    Directory of Open Access Journals (Sweden)

    E Tian

    Full Text Available Congenital heart valve defects in humans occur in approximately 2% of live births and are a major source of compromised cardiac function. In this study we demonstrate that normal heart valve development and cardiac function are dependent upon Galnt1, the gene that encodes a member of the family of glycosyltransferases (GalNAc-Ts responsible for the initiation of mucin-type O-glycosylation. In the adult mouse, compromised cardiac function that mimics human congenital heart disease, including aortic and pulmonary valve stenosis and regurgitation; altered ejection fraction; and cardiac dilation, was observed in Galnt1 null animals. The underlying phenotype is aberrant valve formation caused by increased cell proliferation within the outflow tract cushion of developing hearts, which is first detected at developmental stage E11.5. Developing valves from Galnt1 deficient animals displayed reduced levels of the proteases ADAMTS1 and ADAMTS5, decreased cleavage of the proteoglycan versican and increased levels of other extracellular matrix proteins. We also observed increased BMP and MAPK signaling. Taken together, the ablation of Galnt1 appears to disrupt the formation/remodeling of the extracellular matrix and alters conserved signaling pathways that regulate cell proliferation. Our study provides insight into the role of this conserved protein modification in cardiac valve development and may represent a new model for idiopathic valve disease.

  13. Engineering of a polymer layered bio-hybrid heart valve scaffold

    Energy Technology Data Exchange (ETDEWEB)

    Jahnavi, S., E-mail: jani84@gmail.com [Stem Cell and Molecular Biology Laboratory, Department of Biotechnology, Indian Institute of Technology Madras, Chennai 600036, TN (India); Tissue Culture Laboratory, Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Poojappura, Trivandrum, Kerala 695012 (India); Kumary, T.V., E-mail: tvkumary@yahoo.com [Tissue Culture Laboratory, Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Poojappura, Trivandrum, Kerala 695012 (India); Bhuvaneshwar, G.S., E-mail: gs.bhuvnesh@gmail.com [Trivitron Innovation Centre, Department of Engineering Design, Indian Institute of Technology Madras, Chennai 600036, TN (India); Natarajan, T.S., E-mail: tsniit@gmail.com [Conducting Polymer laboratory, Department of Physics, Indian Institute of Technology, Madras, Chennai 600036, TN (India); Verma, R.S., E-mail: vermars@iitm.ac.in [Stem Cell and Molecular Biology Laboratory, Department of Biotechnology, Indian Institute of Technology Madras, Chennai 600036, TN (India)

    2015-06-01

    Current treatment strategy for end stage valve disease involves either valvular repair or replacement with homograft/mechanical/bioprosthetic valves. In cases of recurrent stenosis/ regurgitation, valve replacement is preferred choice of treatment over valvular repair. Currently available mechanical valves primarily provide durability whereas bioprosthetic valves have superior tissue compatibility but both lack remodelling and regenerative properties making their utility limited in paediatric patients. With advances in tissue engineering, attempts have been made to fabricate valves with regenerative potential using various polymers, decellularized tissues and hybrid scaffolds. To engineer an ideal heart valve, decellularized bovine pericardium extracellular matrix (DBPECM) is an attractive biocompatible scaffold but has weak mechanical properties and rapid degradation. However, DBPECM can be modified with synthetic polymers to enhance its mechanical properties. In this study, we developed a Bio-Hybrid scaffold with non-cross linked DBPECM in its native structure coated with a layer of Polycaprolactone-Chitosan (PCL-CH) nanofibers that displayed superior mechanical properties. Surface and functional studies demonstrated integration of PCL-CH to the DBPECM with enhanced bio and hemocompatibility. This engineered Bio-Hybrid scaffold exhibited most of the physical, biochemical and functional properties of the native valve that makes it an ideal scaffold for fabrication of cardiac valve with regenerative potential. - Highlights: • A Bio-Hybrid scaffold was fabricated with PCL-CH blend and DBPECM. • PCL-CH functionally interacted with decellularized matrix without cross linking. • Modified scaffold exhibited mechanical properties similar to native heart valve. • Supported better fibroblast and endothelial cell adhesion and proliferation. • The developed scaffold can be utilized for tissue engineering of heart valve.

  14. Engineering of a polymer layered bio-hybrid heart valve scaffold

    International Nuclear Information System (INIS)

    Current treatment strategy for end stage valve disease involves either valvular repair or replacement with homograft/mechanical/bioprosthetic valves. In cases of recurrent stenosis/ regurgitation, valve replacement is preferred choice of treatment over valvular repair. Currently available mechanical valves primarily provide durability whereas bioprosthetic valves have superior tissue compatibility but both lack remodelling and regenerative properties making their utility limited in paediatric patients. With advances in tissue engineering, attempts have been made to fabricate valves with regenerative potential using various polymers, decellularized tissues and hybrid scaffolds. To engineer an ideal heart valve, decellularized bovine pericardium extracellular matrix (DBPECM) is an attractive biocompatible scaffold but has weak mechanical properties and rapid degradation. However, DBPECM can be modified with synthetic polymers to enhance its mechanical properties. In this study, we developed a Bio-Hybrid scaffold with non-cross linked DBPECM in its native structure coated with a layer of Polycaprolactone-Chitosan (PCL-CH) nanofibers that displayed superior mechanical properties. Surface and functional studies demonstrated integration of PCL-CH to the DBPECM with enhanced bio and hemocompatibility. This engineered Bio-Hybrid scaffold exhibited most of the physical, biochemical and functional properties of the native valve that makes it an ideal scaffold for fabrication of cardiac valve with regenerative potential. - Highlights: • A Bio-Hybrid scaffold was fabricated with PCL-CH blend and DBPECM. • PCL-CH functionally interacted with decellularized matrix without cross linking. • Modified scaffold exhibited mechanical properties similar to native heart valve. • Supported better fibroblast and endothelial cell adhesion and proliferation. • The developed scaffold can be utilized for tissue engineering of heart valve

  15. Novel imaging strategies for the Detection of Prosthetic Heart Valve Obstruction and Endocarditis

    NARCIS (Netherlands)

    Tanis, W.

    2014-01-01

    Valvular heart disease is accompanied by a high mortality/morbidity and often requires prosthetic heart valve (PHV) replacement in order to improve quality of life and survival. The major drawback of both mechanical and biological PHV implantations is development of dysfunction, which is a life thre

  16. Cardiac rehabilitation increases physical capacity but not mental health after heart valve surgery

    DEFF Research Database (Denmark)

    Sibilitz, Kirstine Lærum; Berg, Selina Klikkenborg; Rasmussen, Trine Bernholdt;

    2016-01-01

    OBJECTIVE: The evidence for cardiac rehabilitation after valve surgery remains sparse. Current recommendations are therefore based on patients with ischaemic heart disease. The aim of this randomised clinical trial was to assess the effects of cardiac rehabilitation versus usual care after heart ...

  17. 75 FR 3238 - Draft Guidance for Industry and Food and Drug Administration Staff; Heart Valves...

    Science.gov (United States)

    2010-01-20

    ... guidance practices regulation. FDA withdrew the 1994 draft on January 5, 2005 (70 FR 824) and is now... Staff; Heart Valves -- Investigational Device Exemption (IDE) and Premarket Approval (PMA) Applications... Administration (FDA) is announcing the availability of the draft guidance document entitled ``Heart...

  18. Joint Modelling of Longitudinal and Survival Data with Applications in Heart Valve Data

    NARCIS (Netherlands)

    E-R. Andrinopoulou (Eleni-Rosalina)

    2014-01-01

    markdownabstract__Abstract__ The heart is one of the most important organs in the entire human body. Specifically, it is a pump composed of muscle which pumps blood throughout the blood vessels to various parts of the body by repeated rhythmic contractions. The four heart valves determine the pathw

  19. A heart team's perspective on interventional mitral valve repair

    DEFF Research Database (Denmark)

    Treede, Hendrik; Schirmer, Johannes; Rudolph, Volker;

    2012-01-01

    Surgical mitral valve repair carries an elevated perioperative risk in the presence of severely reduced ventricular function and relevant comorbidities. We sought to assess the feasibility of catheter-based mitral valve repair using a clip-based percutaneous edge-to-edge repair system in selected...... patients at high surgical risk with mitral regurgitation grade 3 or worse....

  20. RNA-seq analysis to identify novel roles of scleraxis during embryonic mouse heart valve remodeling.

    Directory of Open Access Journals (Sweden)

    Damien N Barnette

    Full Text Available Heart valve disease affects up to 30% of the population and has been shown to have origins during embryonic development. Valvulogenesis begins with formation of endocardial cushions in the atrioventricular canal and outflow tract regions. Subsequently, endocardial cushions remodel, elongate and progressively form mature valve structures composed of a highly organized connective tissue that provides the necessary biomechanical function throughout life. While endocardial cushion formation has been well studied, the processes required for valve remodeling are less well understood. The transcription factor Scleraxis (Scx is detected in mouse valves from E15.5 during initial stages of remodeling, and expression remains high until birth when formation of the highly organized mature structure is complete. Heart valves from Scx-/- mice are abnormally thick and develop fibrotic phenotypes similar to human disease by juvenile stages. These phenotypes begin around E15.5 and are associated with defects in connective tissue organization and valve interstitial cell differentiation. In order to understand the etiology of this phenotype, we analyzed the transcriptome of remodeling valves isolated from E15.5 Scx-/- embryos using RNA-seq. From this, we have identified a profile of protein and non-protein mRNAs that are dependent on Scx function and using bioinformatics we can predict the molecular functions and biological processes affected by these genes. These include processes and functions associated with gene regulation (methyltransferase activity, DNA binding, Notch signaling, vitamin A metabolism (retinoic acid biosynthesis and cellular development (cell morphology, cell assembly and organization. In addition, several mRNAs are affected by alternative splicing events in the absence of Scx, suggesting additional roles in post-transcriptional modification. In summary, our findings have identified transcriptome profiles from abnormal heart valves isolated

  1. Construction of tissue-engineered heart valves by using decellularized scaffolds and endothelial progenitor cells

    Institute of Scientific and Technical Information of China (English)

    FANG Ning-tao; XIE Shang-zhe; WANG Song-mei; GAO Hong-yang; WU Chun-gen; PAN Luan-feng

    2007-01-01

    Background Tissue-engineered heart valves have the potential to overcome the limitations of present heart valve replacements. This study was designed to develop a tissue engineering heart valve by using human umbilical cord blood-derived endothelial progenitor cells (EPCs) and decellularized valve scaffolds.Methods Decellularized valve scaffolds were prepared from fresh porcine heart valves. EPCs were isolated from fresh human umbilical cord blood by density gradient centrifugation, cultured for 3 weeks in EGM-2-MV medium, by which time the resultant cell population became endothelial in nature, as assessed by immunofluorescent staining. EPC-derived endothelial cells were seeded onto the decellularized scaffold at 3 × 106 cells/cm2 and cultured under static conditions for 7 days. Proliferation of the seeded cells on the scaffolds was detected using the MTT assay. Tissue-engineered heart valves were analyzed by HE staining, immunofluorescent staining and scanning electron microscopy. The anti-thrombogenic function of the endothelium on the engineered heart valves was evaluated by platelet adhesion experiments and reverse transcription-polymerase chain reaction (RT-PCR) analysis for the expression of endothelial nitric oxide synthase (eNOS) and tissue-type plasminogen activator (t-PA).Results EPC-derived endothelial cells showed a histolytic cobblestone morphology, expressed specific markers of the endothelial cell lineage including von Willebrand factor (vWF) and CD31, bound a human endothelial cell-specific lectin,Ulex Europaeus agglutinin-1 (UEA-1), and took up Dil-labeled low density lipoprotein (Dil-Ac-LDL). After seeding on the decellularized scaffold, the cells showed excellent metabolic activity and proliferation. The cells formed confluent endothelial monolayers atop the decellularized matrix, as assessed by HE staining and immunostaining for vWF and CD31. Scanning electron microscopy demonstrated the occurrence of tight junctions between cells forming the

  2. Integrating Valve-Inspired Design Features Into Poly(ethylene glycol) Hydrogel Scaffolds For Heart Valve Tissue Engineering

    OpenAIRE

    Zhang, Xing; Xu, Bin; Puperi, Daniel S.; Yonezawa, Aline L.; Wu, Yan; Tseng, Hubert; Cuchiara, Maude L.; West, Jennifer L.; Grande-Allen, K. Jane

    2014-01-01

    The development of advanced scaffolds that recapitulate the anisotropic mechanical behavior and biological functions of the extracellular matrix in leaflets would be transformative for heart valve tissue engineering. In this study, anisotropic mechanical properties were established in poly(ethylene glycol) (PEG) hydrogels by crosslinking stripes of 3.4 kDa PEG diacrylate (PEGDA) within 20 kDa PEGDA base hydrogels using a photolithographic patterning method. Varying the stripe width and spacin...

  3. Effect of heart rate on the hemodynamics of bileaflet mechanical heart valves' prostheses (St. Jude Medical) in the aortic position and in the opening phase: A computational study.

    Science.gov (United States)

    Jahandardoost, Mehdi; Fradet, Guy; Mohammadi, Hadi

    2016-03-01

    To date, to the best of the authors' knowledge, in almost all of the studies performed around the hemodynamics of bileaflet mechanical heart valves, a heart rate of 70-72 beats/min has been considered. In fact, the heart rate of ~72 beats/min does not represent the entire normal physiological conditions under which the aortic or prosthetic valves function. The heart rates of 120 or 50 beats/min may lead to hemodynamic complications, such as plaque formation and/or thromboembolism in patients. In this study, the hemodynamic performance of the bileaflet mechanical heart valves in a wide range of normal and physiological heart rates, that is, 60-150 beats/min, was studied in the opening phase. The model considered in this study was a St. Jude Medical bileaflet mechanical heart valve with the inner diameter of 27 mm in the aortic position. The hemodynamics of the native valve and the St. Jude Medical valve were studied in a variety of heart rates in the opening phase and the results were carefully compared. The results indicate that peak values of the velocity profile downstream of the valve increase as heart rate increases, as well as the location of the maximum velocity changes with heart rate in the St. Jude Medical valve model. Also, the maximum values of shear stress and wall shear stresses downstream of the valve are proportional to heart rate in both models. Interestingly, the maximum shear stress and wall shear stress values in both models are in the same range when heart rate is St. Jude Medical valve model when heart rate is >90 beats/min (up to ~40% growth compared to that of the native valve). The findings of this study may be of importance in the hemodynamic performance of bileaflet mechanical heart valves. They may also play an important role in design improvement of conventional prosthetic heart valves and the design of the next generation of prosthetic valves, such as percutaneous valves. PMID:26786673

  4. Effect of heart rate on the hemodynamics of bileaflet mechanical heart valves' prostheses (St. Jude Medical) in the aortic position and in the opening phase: A computational study.

    Science.gov (United States)

    Jahandardoost, Mehdi; Fradet, Guy; Mohammadi, Hadi

    2016-03-01

    To date, to the best of the authors' knowledge, in almost all of the studies performed around the hemodynamics of bileaflet mechanical heart valves, a heart rate of 70-72 beats/min has been considered. In fact, the heart rate of ~72 beats/min does not represent the entire normal physiological conditions under which the aortic or prosthetic valves function. The heart rates of 120 or 50 beats/min may lead to hemodynamic complications, such as plaque formation and/or thromboembolism in patients. In this study, the hemodynamic performance of the bileaflet mechanical heart valves in a wide range of normal and physiological heart rates, that is, 60-150 beats/min, was studied in the opening phase. The model considered in this study was a St. Jude Medical bileaflet mechanical heart valve with the inner diameter of 27 mm in the aortic position. The hemodynamics of the native valve and the St. Jude Medical valve were studied in a variety of heart rates in the opening phase and the results were carefully compared. The results indicate that peak values of the velocity profile downstream of the valve increase as heart rate increases, as well as the location of the maximum velocity changes with heart rate in the St. Jude Medical valve model. Also, the maximum values of shear stress and wall shear stresses downstream of the valve are proportional to heart rate in both models. Interestingly, the maximum shear stress and wall shear stress values in both models are in the same range when heart rate is valve model when heart rate is >90 beats/min (up to ~40% growth compared to that of the native valve). The findings of this study may be of importance in the hemodynamic performance of bileaflet mechanical heart valves. They may also play an important role in design improvement of conventional prosthetic heart valves and the design of the next generation of prosthetic valves, such as percutaneous valves.

  5. The value of MRI in the diagnosis of heart valve diseases

    International Nuclear Information System (INIS)

    Objective: To assess the diagnostic value of the magnetic resonance imaging (MRI) for heart valve disease qualitatively and quantitatively. Methods: From 18th Sep, 2004 to 30th Jun, 2005, 56 consecutive patients underwent MR scanning with multiple sequences, including two-dimensional dark and bright sequences, K-space segmented TrueFISP and FLASH cine sequences, as well as velocity-encoded cine MR(VEC-MR). Morphologic and functional parameters were applied to assess the disease qualitatively and quantitatively. For quantitative analysis, Doppler echocardiography was compared to evaluate the reliability of VEC-MR in assessing the severity of aortic valve disease. Correlations coefficient was analyzed by a statistic software (SPSS 13.0), Psq=0.951, P=0.01 for AS and R=0.965, Rsq=0.932, P<0.01 for AI). Conclusion: Heart valve diseases can be qualitatively and quantitatively evaluated by MR multiple sequences, especially in aortic valve disease. (authors)

  6. Fabrication of a Novel Hybrid Scaffold for Tissue Engineered Heart Valve

    Institute of Scientific and Technical Information of China (English)

    Hao HONG; Niangno DONG; Jiawei SHI; Si CHEN; Chao GUO; Ping HU; Hongxu QI

    2009-01-01

    The aim of this study was to fabricate biomatrix/polymer hybrid scaffolds using an elec-trospinning technique. Then tissue engineered heart valves were engineered by seeding mesenchymal stromal cells (MSCs) onto the scaffolds. The effects of the hybrid scaffolds on the proliferation of seed cells, formation of extracellular matrix and mechanical properties of tissue engineered heart valves were investigated. MSCs were obtained from rats. Porcine aortic heart valves were decellularized, coated with poly(3-hydroxybutyrate-co-4-hydroxybutyrate) using an electrospinning technique, and reseeded and cultured over a time period of 14 days. In control group, the decellularized valve scaffolds were re-seeded and cultured over an equivalent time period. Specimens of each group were examined histologi-cally (hematoxylin-eosin [HE] staining, immunohistostaining, and scanning electron microscopy), bio-chemically (DNA and 4-hydroxyproline) and mechanically. The results showed that recellularization was comparable to the specimens of hybrid scaffolds and controls. The specimens of hybrid scaffolds and controls revealed comparable amounts of cell mass and 4-hydroxyproline (P>0.05). However, the specimens of hybrid scaffolds showed a significant increase in mechanical strength, compared to the controls (P<0.05). This study demonstrated the superiority of the hybrid scaffolds to increase the me-chanical strength of tissue engineered heart valves. And compared to the decellularized valve scaffolds,the hybrid scaffolds showed similar effects on the proliferation of MSCs and formation of extracellular matrix. It was believed that the hybrid scaffolds could be used for the construction of tissue engineered heart valves.

  7. Multidetector CT imaging of mechanical prosthetic heart valves: quantification of artifacts with a pulsatile in-vitro model

    NARCIS (Netherlands)

    P. Symersky; R.P.J. Budde; P. Westers; B.A.J.M. de Mol; M. Prokop

    2011-01-01

    Multidetector computed tomography (MDCT) can detect the cause of prosthetic heart valve (PHV) dysfunction but is hampered by valve-induced artifacts. We quantified artifacts of four PHV using a pulsatile in-vitro model and assessed the relation to leaflet motion and valve design. A Medtronic Hall ti

  8. Multidetector CT imaging of mechanical prosthetic heart valves : quantification of artifacts with a pulsatile in-vitro model

    NARCIS (Netherlands)

    Symersky, Petr; Budde, Ricardo P. J.; Westers, Paul; de Mol, Bas A. J. M.; Prokop, Mathias

    2011-01-01

    Objectives Multidetector computed tomography (MDCT) can detect the cause of prosthetic heart valve (PHV) dysfunction but is hampered by valve-induced artifacts. We quantified artifacts of four PHV using a pulsatile in-vitro model and assessed the relation to leaflet motion and valve design. Methods

  9. Multidetector CT imaging of mechanical prosthetic heart valves: quantification of artifacts with a pulsatile in-vitro model

    NARCIS (Netherlands)

    Symersky, P.; Budde, R.P.; Westers, P.; Mol, B.A. de; Prokop, M.

    2011-01-01

    OBJECTIVES: Multidetector computed tomography (MDCT) can detect the cause of prosthetic heart valve (PHV) dysfunction but is hampered by valve-induced artifacts. We quantified artifacts of four PHV using a pulsatile in-vitro model and assessed the relation to leaflet motion and valve design. METHODS

  10. Cardiac rehabilitation patient's perspectives on the recovery following heart valve surgery: a narrative analysis

    DEFF Research Database (Denmark)

    Hansen, Tina Birgitte; Zwisler, Ann Dorthe Olsen; Berg, Selina Kikkenborg;

    2016-01-01

    AIMS: To explore the structure and content of narratives about the recovery process among patients undergoing heart valve surgery participating in cardiac rehabilitation. BACKGROUND: Several studies with short-term follow-up have shown that recovering from cardiac surgery can be challenging, but ...... benefit from more extensive medical follow-up immediately after discharge, individual psychological assessment and individualized, realistic information about the recovery trajectory.......AIMS: To explore the structure and content of narratives about the recovery process among patients undergoing heart valve surgery participating in cardiac rehabilitation. BACKGROUND: Several studies with short-term follow-up have shown that recovering from cardiac surgery can be challenging......, but evidence on the long-term recovery process is very limited, especially following heart valve surgery. Furthermore, few studies have explored the recovery process among cardiac rehabilitation participants. DESIGN: A qualitative study with serial interviews analysed using narrative methods. METHODS: We...

  11. Self-management of oral anticoagulant therapy for mechanical heart valve patients

    DEFF Research Database (Denmark)

    Christensen, Thomas D; Attermann, Jørn; Pilegaard, Hans K;

    2001-01-01

    .4%–2.9%) for the control group. Conclusion: Self-management of OAT is a feasible and safe concept for selected patients with mechanical heart valve prostheses also on a long-term basis. It provides at least as good and most likely better quality of anticoagulant therapy than conventional management assessed by time within......Objective: Self-management of oral anticoagulant therapy (OAT) has shown good results on a short-term basis. We hypothesize that self-management of OAT provides a better quality of treatment than conventional management also on a long-term basis. The aim of this study was to assess the quality...... of self-management of OAT in patients with mechanical heart valve prostheses on a 4-year perspective in a prospective, non-randomized study. Design: Twenty-four patients with mechanical heart valves and on self-managed OAT were followed for up to 4 years. A matched, retrospectively selected group...

  12. FDA's requirements for in-vivo performance data for prosthetic heart valves.

    Science.gov (United States)

    Johnson, D M; Sapirstein, W

    1994-07-01

    The Food and Drug Administration (FDA) has recently revised its "Replacement Heart Valve Guidance". That document lists the data FDA deems necessary to support the approval of new prosthetic heart valves of all designs, and which should be contained in Premarket Approval Applications for these devices. The guidance covers detailed data requirements for in vitro, animal, and clinical data. This paper is intended to briefly summarize FDA's requirements for in vivo and clinical data. The clinical study must establish that the device is both safe and effective, as compared to currently marketed replacement heart valves. It is possible to achieve this goal using hypothesis testing to compare the results of an observational study against a set of Objective Performance Criteria (OPC) which have been established by the FDA. The establishment of the OPCs was facilitated by a standardized set of definitions of complications published by the American Association of Thoracic Surgery and Society of Thoracic Surgeons (AATS/STS) in 1987/1988. Papers published in peer reviewed journals have utilized this set of definitions for data analysis, providing an ample pool of data from which to establish OPCs. The number of patients required to establish the safety and efficacy of a replacement heart valve, using this approach, is 800 valve years, 400 in the aortic and 400 in the mitral position. Advantages of this approach are reduction in the number of patients and duration of the study. PMID:7952304

  13. Imaging in the context of replacement heart valve development: use of the Visible Heart(®) methodologies.

    Science.gov (United States)

    Bateman, Michael G; Iaizzo, Paul A

    2012-09-01

    In recent years huge strides have been made in the fields of interventional cardiology and cardiac surgery which now allow physicians and surgeons to repair or replace cardiac valves with greater success in a larger demographic of patients. Pivotal to these advances has been significant improvements in cardiac imaging and improved fundamental understanding of valvular anatomies and morphologies. We describe here a novel series of techniques utilized within the Visible Heart(®) laboratory by engineers, scientists, and/or anatomists to visualize and analyze the form and function of the four cardiac valves and to assess potential repair or replacement therapies. The study of reanimated large mammalian hearts (including human hearts) using various imaging modalities, as well as specially prepared anatomical specimens, has enhanced the design, development, and testing of novel cardiac therapies. PMID:24282719

  14. Imaging in the context of replacement heart valve development: use of the Visible Heart(®) methodologies.

    Science.gov (United States)

    Bateman, Michael G; Iaizzo, Paul A

    2012-09-01

    In recent years huge strides have been made in the fields of interventional cardiology and cardiac surgery which now allow physicians and surgeons to repair or replace cardiac valves with greater success in a larger demographic of patients. Pivotal to these advances has been significant improvements in cardiac imaging and improved fundamental understanding of valvular anatomies and morphologies. We describe here a novel series of techniques utilized within the Visible Heart(®) laboratory by engineers, scientists, and/or anatomists to visualize and analyze the form and function of the four cardiac valves and to assess potential repair or replacement therapies. The study of reanimated large mammalian hearts (including human hearts) using various imaging modalities, as well as specially prepared anatomical specimens, has enhanced the design, development, and testing of novel cardiac therapies.

  15. Surface modification of polyurethane films by plasma and ultraviolet light to improve haemocompatibility for artificial heart valves

    OpenAIRE

    Alves, P.; Cardoso, R; Correia, T. R.; Antunes, B. P.; Correia, I. J.; Ferreira, P.

    2014-01-01

    Prosthetic cardiac valves implantation is a common procedure used to treat heart valve diseases. Although there are different prostheses already available in the market (either mechanical or bioprosthetic), their use presents several problems, specifically concerning thrombogenicity and structural failure. Recently, some progresses have been achieved in developing heart valves based on synthetic materials with special emphasis in polymers. Among them, polyurethanes are one of the most commonl...

  16. Sox9 is required for precursor cell expansion and extracellular matrix organization during mouse heart valve development

    OpenAIRE

    Lincoln, Joy; Kist, Ralf; Scherer, Gerd; Yutzey, Katherine E.

    2007-01-01

    Heart valve structures derived from mesenchymal cells of the endocardial cushions (EC) are composed of highly organized cell lineages and extracellular matrix. Sox9 is a transcription factor required for both early and late stages of cartilage formation that is also expressed in the developing valves of the heart. The requirements for Sox9 function during valvulogenesis and adult valve homeostasis in mice were examined by conditional inactivation of Sox9 using Tie2-cre and Col2a1-cre transgen...

  17. Decellularized homologous tissue-engineered heart valves as off-the-shelf alternatives to xeno- and homografts

    OpenAIRE

    Dijkman, Petra E; Driessen-Mol, Anita; Frese, Laura; Hoerstrup, Simon P.; Baaijens, Frank P.T.

    2012-01-01

    Decellularized xenogenic or allogenic heart valves have been used as starter matrix for tissue-engineering of valve replacements with (pre-)clinical promising results. However, xenografts are associated with the risk of immunogenic reactions or disease transmission and availability of homografts is limited. Alternatively, biodegradable synthetic materials have been used to successfully create tissue-engineered heart valves (TEHV). However, such TEHV are associated with substantial technologic...

  18. Fiber heart valve prosthesis: Early in vitro fatigue results.

    Science.gov (United States)

    Vaesken, Antoine; Khoffi, Foued; Heim, Frederic; Dieval, Florence; Chakfe, Nabil

    2016-07-01

    Transcatheter aortic valve replacement has become today a largely considered alternative technique to surgical valve replacement in patients with high risk for open chest surgery. Biological valve tissue used in the transcatheter devices has shown success over 5 years now, but the procedure remains expensive. Moreover, different studies point out potential degradations that the tissue can undergo when folded to lower diameter and released in calcified environment with irregular geometry, which may jeopardize the durability of the device. The use of synthetic materials, like textile in particular, to replace biological valve leaflets would help reducing the procedure costs, and limit the degradations when the valve is crimped. Textile polyester material has been extensively used in the vascular surgery and is characterized by outstanding folding and strength properties combined with proven biocompatibility. However, the friction effects that occur between filaments and between yarns within a fabric under flexure loading could be critical for the resistance of the material on the long term. The purpose of this study was to assess the early fatigue performances of textile valve prototypes under accelerated cyclic loading up to 200 Mio cycles. Durability tests show that the fibrous material undergoes rearrangements between fibrous elements within the textile construction and the mechanical properties are modified on the long term. But testing is not complete with 200 Mio cycles. The material should be tested up to a higher number of cycles in future work to test the effective long-term durability. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 986-992, 2016. PMID:25980361

  19. Integrating valve-inspired design features into poly(ethylene glycol) hydrogel scaffolds for heart valve tissue engineering.

    Science.gov (United States)

    Zhang, Xing; Xu, Bin; Puperi, Daniel S; Yonezawa, Aline L; Wu, Yan; Tseng, Hubert; Cuchiara, Maude L; West, Jennifer L; Grande-Allen, K Jane

    2015-03-01

    The development of advanced scaffolds that recapitulate the anisotropic mechanical behavior and biological functions of the extracellular matrix in leaflets would be transformative for heart valve tissue engineering. In this study, anisotropic mechanical properties were established in poly(ethylene glycol) (PEG) hydrogels by crosslinking stripes of 3.4 kDa PEG diacrylate (PEGDA) within 20 kDa PEGDA base hydrogels using a photolithographic patterning method. Varying the stripe width and spacing resulted in a tensile elastic modulus parallel to the stripes that was 4.1-6.8 times greater than that in the perpendicular direction, comparable to the degree of anisotropy between the circumferential and radial orientations in native valve leaflets. Biomimetic PEG-peptide hydrogels were prepared by tethering the cell-adhesive peptide RGDS and incorporating the collagenase-degradable peptide PQ (GGGPQG↓IWGQGK) into the polymer network. The specific amounts of RGDS and PEG-PQ within the resulting hydrogels influenced the elongation, de novo extracellular matrix deposition and hydrogel degradation behavior of encapsulated valvular interstitial cells (VICs). In addition, the morphology and activation of VICs grown atop PEG hydrogels could be modulated by controlling the concentration or micro-patterning profile of PEG-RGDS. These results are promising for the fabrication of PEG-based hydrogels using anatomically and biologically inspired scaffold design features for heart valve tissue engineering. PMID:25433168

  20. Results of Heart Valve Replacement with the SORIN Prosthesis

    OpenAIRE

    Colombo, Tiziano; Donatelli, Francesco; Quaini, Eugenio; Vitali, Ettore; Pellegrini, Alessandro

    1987-01-01

    From March 1977 to December 1981, 872 patients at our institution underwent valve replacement with a pyrolytic carbon tilting disc prosthesis manufactured in Italy by SORIN-Biomedica. To verify the performance characteristics of this prosthesis, we analyzed the intermediate-term results obtained over a cumulative total of 3,041 patient-years (pt-yr) of follow-up.

  1. Tissue-Engineered Fibrin-Based Heart Valve with Bio-Inspired Textile Reinforcement.

    Science.gov (United States)

    Moreira, Ricardo; Neusser, Christine; Kruse, Magnus; Mulderrig, Shane; Wolf, Frederic; Spillner, Jan; Schmitz-Rode, Thomas; Jockenhoevel, Stefan; Mela, Petra

    2016-08-01

    The mechanical properties of tissue-engineered heart valves still need to be improved to enable their implantation in the systemic circulation. The aim of this study is to develop a tissue-engineered valve for the aortic position - the BioTexValve - by exploiting a bio-inspired composite textile scaffold to confer native-like mechanical strength and anisotropy to the leaflets. This is achieved by multifilament fibers arranged similarly to the collagen bundles in the native aortic leaflet, fixed by a thin electrospun layer directly deposited on the pattern. The textile-based leaflets are positioned into a 3D mould where the components to form a fibrin gel containing human vascular smooth muscle cells are introduced. Upon fibrin polymerization, a complete valve is obtained. After 21 d of maturation by static and dynamic stimulation in a custom-made bioreactor, the valve shows excellent functionality under aortic pressure and flow conditions, as demonstrated by hydrodynamic tests performed according to ISO standards in a mock circulation system. The leaflets possess remarkable burst strength (1086 mmHg) while remaining pliable; pronounced extracellular matrix production is revealed by immunohistochemistry and biochemical assay. This study demonstrates the potential of bio-inspired textile-reinforcement for the fabrication of functional tissue-engineered heart valves for the aortic position. PMID:27377438

  2. A biocompatible flow chamber to study the hemodynamic performance of prosthetic heart valves.

    Science.gov (United States)

    Yin, Wei; Ngwe, Ek Ching; Rubenstein, David A

    2012-01-01

    The goal of this study was to design, fabricate, and characterize a biocompatible flow chamber to study the performance of artificial heart valves. The system consists of a testing fluid chamber and a water chamber (separated by a latex diaphragm), following the design of a left ventricular assist device. Two St. Jude bileaflet mechanical heart valves were placed oppositely in the testing fluid chamber to control flow direction. The flow rate of the testing fluid chamber was set at 5.6 L/min, with a stroke volume of 80 ml. The performance of the system was examined through three-dimensional numerical simulation and in vitro experiments with whole blood and washed platelets. Hemolysis was measured with whole blood using a spectrophotometer. Platelet activation was measured by platelet surface P-selectin expression using flow cytometry. The three-dimensional computational fluid dynamics model demonstrated that the flow field in the chamber was laminar and physiological. Results from in vitro experiments indicated that the flow conditions in the chamber did not induce hemolysis or platelet activation with the presence of St. Jude heart valves. Overall, the flow chamber can provide a feasible environment to study the hemodynamic performance of artificial heart valves. PMID:22951894

  3. New electromagnetic methods for the evaluation of prosthetic heart valves (invited)

    Science.gov (United States)

    Udpa, Satish

    2002-05-01

    Prosthetic devices are being implanted at record levels as the nation "ages" and advances in prosthetic science are made. Devices that are implanted range from artificial limbs and hips to devices such as heart valves. Periodic evaluation of the state of the devices is of significant interest particularly in the case of prosthetics whose failure can be fatal. An example of such a device is the artificial heart valve. Heart valves are usually replaced when stenosis or incompetence is indicated. This article presents a selection of some new techniques that are being developed for the detection of outlet strut failures in Bjork-Shiley heart valves. Methods that show particular promise include a noninvasive electromagnetic method that relies on the excitation and measurement of the resonant vibration modes of the strut. An alternate approach involves the induction of currents in the outlet strut using a pair of external excitation coils. The field generated by the current induced in the strut perturbs the field generated by the excitation coils. The field perturbations are measured using a catheter-mounted gradiometer. Test results obtained using an experimental rig designed to demonstrate the proof-of-concept are presented.

  4. Long-term tricuspid valve prosthesis-related complications in patients with congenital heart disease

    NARCIS (Netherlands)

    van Slooten, Ymkje J.; Freling, Hendrik G.; van Melle, Joost P.; Mulder, Barbara J. M.; Jongbloed, Monique R. M.; Ebels, Tjark; Voors, Adriaan A.; Pieper, Petronella G.

    2014-01-01

    OBJECTIVES: In patients with acquired valvar disease, morbidity and mortality rates after tricuspid valve replacement (TVR) are high. However, in adult patients with congenital heart disease, though data concerning outcome after TVR are scarce, even poorer results are suggested in patients with Ebst

  5. Biomechanical conditioning of tissue engineered heart valves: Too much of a good thing?

    Science.gov (United States)

    Parvin Nejad, Shouka; Blaser, Mark C; Santerre, J Paul; Caldarone, Christopher A; Simmons, Craig A

    2016-01-15

    Surgical replacement of dysfunctional valves is the primary option for the treatment of valvular disease and congenital defects. Existing mechanical and bioprosthetic replacement valves are far from ideal, requiring concomitant anticoagulation therapy or having limited durability, thus necessitating further surgical intervention. Heart valve tissue engineering (HVTE) is a promising alternative to existing replacement options, with the potential to synthesize mechanically robust tissue capable of growth, repair, and remodeling. The clinical realization of a bioengineered valve relies on the appropriate combination of cells, biomaterials, and/or bioreactor conditioning. Biomechanical conditioning of valves in vitro promotes differentiation of progenitor cells to tissue-synthesizing myofibroblasts and prepares the construct to withstand the complex hemodynamic environment of the native valve. While this is a crucial step in most HVTE strategies, it also may contribute to fibrosis, the primary limitation of engineered valves, through sustained myofibrogenesis. In this review, we examine the progress of HVTE and the role of mechanical conditioning in the synthesis of mechanically robust tissue, and suggest approaches to achieve myofibroblast quiescence and prevent fibrosis.

  6. Scleraxis is required for cell lineage differentiation and extracellular matrix remodeling during murine heart valve formation in vivo.

    Science.gov (United States)

    Levay, Agata K; Peacock, Jacqueline D; Lu, Yinhui; Koch, Manuel; Hinton, Robert B; Kadler, Karl E; Lincoln, Joy

    2008-10-24

    Heart valve structures, derived from mesenchyme precursor cells, are composed of differentiated cell types and extracellular matrix arranged to facilitate valve function. Scleraxis (scx) is a transcription factor required for tendon cell differentiation and matrix organization. This study identified high levels of scx expression in remodeling heart valve structures at embryonic day 15.5 through postnatal stages using scx-GFP reporter mice and determined the in vivo function using mice null for scx. Scx(-/-) mice display significantly thickened heart valve structures from embryonic day 17.5, and valves from mutant mice show alterations in valve precursor cell differentiation and matrix organization. This is indicated by decreased expression of the tendon-related collagen type XIV, increased expression of cartilage-associated genes including sox9, as well as persistent expression of mesenchyme cell markers including msx1 and snai1. In addition, ultrastructure analysis reveals disarray of extracellular matrix and collagen fiber organization within the valve leaflet. Thickened valve structures and increased expression of matrix remodeling genes characteristic of human heart valve disease are observed in juvenile scx(-/-) mice. In addition, excessive collagen deposition in annular structures within the atrioventricular junction is observed. Collectively, our studies have identified an in vivo requirement for scx during valvulogenesis and demonstrate its role in cell lineage differentiation and matrix distribution in remodeling valve structures.

  7. Nursing leadership of the transcatheter aortic valve implantation Heart Team: Supporting innovation, excellence, and sustainability.

    Science.gov (United States)

    Lauck, Sandra B; McGladrey, Janis; Lawlor, Cindy; Webb, John G

    2016-05-01

    Transcatheter Aortic Valve Implantation (TAVI) is an innovative and resource-intensive treatment of valvular heart disease. Growing evidence and excellent outcomes are contributing to increased patient demand. The Heart Team is foundational to TAVI programs to manage the complexities of case selection and other aspects of care. The competencies and expertise of nurses are well suited to provide administrative and clinical leadership within the TAVI Heart Team to promote efficient, effective, and sustainable program development. The contributions of nursing administrative and clinical leaders exemplify the leadership roles that nurses can assume in healthcare innovation. PMID:27060802

  8. Nursing leadership of the transcatheter aortic valve implantation Heart Team: Supporting innovation, excellence, and sustainability.

    Science.gov (United States)

    Lauck, Sandra B; McGladrey, Janis; Lawlor, Cindy; Webb, John G

    2016-05-01

    Transcatheter Aortic Valve Implantation (TAVI) is an innovative and resource-intensive treatment of valvular heart disease. Growing evidence and excellent outcomes are contributing to increased patient demand. The Heart Team is foundational to TAVI programs to manage the complexities of case selection and other aspects of care. The competencies and expertise of nurses are well suited to provide administrative and clinical leadership within the TAVI Heart Team to promote efficient, effective, and sustainable program development. The contributions of nursing administrative and clinical leaders exemplify the leadership roles that nurses can assume in healthcare innovation.

  9. Cardiac Hemodynamics in the Pathogenesis of Congenital Heart Disease and Aortic Valve Calcification

    Science.gov (United States)

    Nigam, Vishal

    2011-11-01

    An improved understanding of the roles of hemodynamic forces play in cardiac development and the pathogenesis of cardiac disease will have significant scientific and clinical impact. I will focus on the role of fluid dynamics in congenital heart disease and aortic valve calcification. Congenital heart defects are the most common form of birth defect. Aortic valve calcification/stenosis is the third leading cause of adult heart disease and the most common form of acquired valvular disease in developed countries. Given the high incidence of these diseases and their associated morbidity and mortality, the potential translational impact of an improved understanding of cardiac hemodynamic forces is very large. Division of Pediatric Cardiology, Rady Children's Hospital, San Diego

  10. Severe Bioprosthetic Mitral Valve Stenosis and Heart Failure in a Young Woman with Systemic Lupus Erythematosus

    Science.gov (United States)

    Wartak, Siddharth; Sadiq, Adnan; Crooke, Gregory; Moskovits, Manfred; Frankel, Robert; Hollander, Gerald; Shani, Jacob

    2016-01-01

    A 23-year-old African American woman with a past medical history of systemic lupus erythematous (SLE), secondary hypertension, and end stage renal disease (ESRD) on hemodialysis for eight years was stable until she developed symptomatic severe mitral regurgitation with preserved ejection fraction. She underwent a bioprosthetic mitral valve replacement (MVR) at outside hospital. However, within a year of her surgery, she presented to our hospital with NYHA class IV symptoms. She was treated for heart failure but in view of her persistent symptoms and low EF was considered for heart and kidney transplant. This was a challenge in view of her history of lupus. We presumed that her stenosis of bioprosthetic valve was secondary to lupus and renal disease. We hypothesized that her low ejection fraction was secondary to mitral stenosis and potentially reversible. We performed a dobutamine stress echocardiogram, which revealed an improved ejection fraction to more than 50% and confirmed preserved inotropic contractile reserve of her myocardium. Based on this finding, she underwent a metallic mitral valve and tricuspid valve replacement. Following surgery, her symptoms completely resolved. This case highlights the pathophysiology of lupus causing stenosis of prosthetic valves and low ejection cardiomyopathy.

  11. Experimental Observation on Antithrombotic Property of A New Bileaflet Mechanical Heart Valve in Sheep

    Institute of Scientific and Technical Information of China (English)

    LOU Hai-fang; XU Si-wei

    2008-01-01

    Objective: To observe the antithrombotic property of a new all-pyrolytic car-bon bileaflet mechanical heart valve so as to provide evidence for clinical practice. Meth-ods: 15 sheep underwent mitral valve replacement (MVR) with this new mechanical valve. Each animal was placed on cardiopulmonary bypass. All of the sheep were given in an anticoagulation protocol and followed for three months. Final studies were performed on all animals surviving for more than 12 weeks. Results: 10 sheep died within 48 h after op-eration, 5 sheep survived. The long-term survivors were killed for autopsies,2 sheep were killed after 1 week, 1 after 12 weeks and 2 after two and half years. Pathological examina-tion of 10 sheep which died early after operation revealed that there was neither evidence of thrombosis nor any failure of the mechanical valve. Autopsy studies in the 5 long-term survivors revealed that the sewing ring was covered by a thin layer of microthrombi consis-ted most of platelets and fibrin after 1 week. The sewing ring was covered by a tissue lay-er, with partial organized microthrombi and endothelialization after 12 weeks. Two and half years after operation, the complete endothelialization presented around the sewing ring without restriction of bileaflet motion. The tissue ingrowth tends to stop at the pyrolytic carbon-fabric interface on both surfaces of left atrium and ventricle. This study demonstra-ted that the new prosthetic heart valve had not promoted thrombosis and thrombembolism.

  12. RELATION OF PERIOPERATIVE SERUM THYROID HORMONE CHANGES TO HEART DYSFUNCTION IN PATIENTS UNDERGONE CARDIAC VALVE REPLACEMENT

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective To explore the relationship between perioperative serum thyroid hormone changes and heart dysfunction in patients undergone cardiac valve replacement. Methods The serum concentrations of free tri- iodothyronine (),free thyroxine (),total total reverse and thyroid-stimulating hor- mone (TSH) in 20 patients undergone routine rheumatic mitral valve replacement were determined by radioim- munoassay at preoperation, the end of myocardial ischemia, and 2,6,12,24 and 48h postoperation, respectively. The alteration hormones above mentioned were comparatively analysed of the normal heart function group (group I,n = 14) and heart dysfunction group (group I ,n=6) after surgery. Results In comparing group I with group I , the more severe the chronic congestive heart failure, the lower the thyroid hormone level before operation;and subse- quently both progressively lowered T3 level and acute heart dysfunction emerged after operation. The decreased extent of serum thyroid hormone was closely parallel to the severity of heart dysfunction. Gonclusion Perioperatively, de- creased serum FT3 and TT3 concentrations are at least an important humoral factor aggravating heart dysfunction, and the patients with preoperative low T3 should be considered as high-risk valvular surgical cases.

  13. Multiple-Step Injection Molding for Fibrin-Based Tissue-Engineered Heart Valves.

    Science.gov (United States)

    Weber, Miriam; Gonzalez de Torre, Israel; Moreira, Ricardo; Frese, Julia; Oedekoven, Caroline; Alonso, Matilde; Rodriguez Cabello, Carlos J; Jockenhoevel, Stefan; Mela, Petra

    2015-08-01

    Heart valves are elaborate and highly heterogeneous structures of the circulatory system. Despite the well accepted relationship between the structural and mechanical anisotropy and the optimal function of the valves, most approaches to create tissue-engineered heart valves (TEHVs) do not try to mimic this complexity and rely on one homogenous combination of cells and materials for the whole construct. The aim of this study was to establish an easy and versatile method to introduce spatial diversity into a heart valve fibrin scaffold. We developed a multiple-step injection molding process that enables the fabrication of TEHVs with heterogeneous composition (cell/scaffold material) of wall and leaflets without the need of gluing or suturing components together, with the leaflets firmly connected to the wall. The integrity of the valves and their functionality was proved by either opening/closing cycles in a bioreactor (proof of principle without cells) or with continuous stimulation over 2 weeks. We demonstrated the potential of the method by the two-step molding of the wall and the leaflets containing different cell lines. Immunohistology after stimulation confirmed tissue formation and demonstrated the localization of the different cell types. Furthermore, we showed the proof of principle fabrication of valves using different materials for wall (fibrin) and leaflets (hybrid gel of fibrin/elastin-like recombinamer) and with layered leaflets. The method is easy to implement, does not require special facilities, and can be reproduced in any tissue-engineering lab. While it has been demonstrated here with fibrin, it can easily be extended to other hydrogels. PMID:25654448

  14. Manipulation of the closing transients of bileaflet mechanical heart valves using passive, surface-mounted elements

    Science.gov (United States)

    Simon, Helene

    2005-11-01

    The time-periodic closing of bileaflet mechanical heart valves is accompanied by a strong flow transient that is associated with the formation of a counter-rotating vortex pair near the b-datum line of leaflet edges. The strong transitory shear that is generated by these vortices may be damaging to blood elements and may result in platelet activation. In the present work, these flow transients are mitigated using miniature vortex generator arrays that are embedded on the surface of the leaflets. The closing transients in the absence and presence of the passive vortex generators are characterized using PIV measurements that are phase locked to the leaflet motion. The study utilizes a 25 mm St. Jude Medical valve placed in the aortic position of the Georgia Tech left heart simulator. The valve is subjected to physiological flow conditions: a heart rate of 70 bpm; a cardiac output of 5 l/min; and a mean aortic pressure of 90 mmHg. Measurements of the velocity field in the center plane of the leaflets demonstrate that the dynamics of the transient vortices that precede the formation of the leakage jets can be significantly altered and controlled by relatively simple passive modifications of existing valve designs.

  15. Cell-mediated retraction versus hemodynamic loading - A delicate balance in tissue-engineered heart valves.

    Science.gov (United States)

    van Loosdregt, Inge A E W; Argento, Giulia; Driessen-Mol, Anita; Oomens, Cees W J; Baaijens, Frank P T

    2014-06-27

    Preclinical studies of tissue-engineered heart valves (TEHVs) showed retraction of the heart valve leaflets as major failure of function mechanism. This retraction is caused by both passive and active cell stress and passive matrix stress. Cell-mediated retraction induces leaflet shortening that may be counteracted by the hemodynamic loading of the leaflets during diastole. To get insight into this stress balance, the amount and duration of stress generation in engineered heart valve tissue and the stress imposed by physiological hemodynamic loading are quantified via an experimental and a computational approach, respectively. Stress generation by cells was measured using an earlier described in vitro model system, mimicking the culture process of TEHVs. The stress imposed by the blood pressure during diastole on a valve leaflet was determined using finite element modeling. Results show that for both pulmonary and systemic pressure, the stress imposed on the TEHV leaflets is comparable to the stress generated in the leaflets. As the stresses are of similar magnitude, it is likely that the imposed stress cannot counteract the generated stress, in particular when taking into account that hemodynamic loading is only imposed during diastole. This study provides a rational explanation for the retraction found in preclinical studies of TEHVs and represents an important step towards understanding the retraction process seen in TEHVs by a combined experimental and computational approach. PMID:24268314

  16. Aortic root compliance influences hemolysis in mechanical heart valve prostheses: an in-vitro study.

    Science.gov (United States)

    Linde, Torsten; Hamilton, Kathrin F; Navalon, Elena Cuenca; Schmitz-Rode, Thomas; Steinseifer, Ulrich

    2012-07-01

    Mechanical heart valve prostheses are known to activate coagulation and cause hemolysis. Both are particularly dependent on the leaflet dynamics, which in turn depends on the flow field in the aortic root influenced by the aortic root geometry and its compliance. Compliance reduction of large vessels occurs in aging patients, both in those who have atherosclerotic diseases and those who do not. In this study we investigated the correlation between hemolysis and the compliance of the proximal aorta in a novel, pulsatile in vitro blood tester using porcine blood. Two mechanical heart valves, the St Jude Medical (SJM) bileaflet valve and a trileaflet valve prototype (Triflo) were tested for hemolysis under physiological conditions (120/80 mm Hg, 4.5 l/min, 70 bpm) and using two different tester setups: with a stiff aorta and with a compliant aorta. Valve dynamics were subsequently analyzed via high-speed videos. In the tests with the Triflo valve, the free plasma hemoglobin increased by 13.4 mg/dl for the flexible and by 19.3 mg/dl for the stiff setup during the 3-hour test. The FFT spectra and closing speed showed slight differences for both setups. Free plasma hemoglobin for the SJM valve was up by 22.2 mg/dl in the flexible and 42.7 mg/dl in the stiff setup. Cavitation induced by the higher closing speed might be responsible for this, which is also indicated by the sound spectrum elevation above 16 kHz. PMID:22669587

  17. [Preliminary study of a new heart valve prostheses implanted with minimally invasive techniques: pulsatile-flow testing in vitro].

    Science.gov (United States)

    Tang, Jinglong; Wang, Shuo; Liu, Li; Wang, Jian; Wang, Chunren

    2013-02-01

    The aim of this study was to investigate the pulsatile-flow performance in vitro of a new heart valve prostheses implanted with minimally invasive techniques (HVPMIT). Three HVPMITs were tested valves and another three original biological heart valve prostheses acted as reference valves. The pulsatile-flow parameters (including mean pressure drop, regurgitant percentage of stroke volume, and effective orifice area) were tested in a pulse duplicator according to the methods listed in ISO5840-2005 and GB 12279-2008. The results demonstrated that the regurgitant percentage of stroke volume of tested valves was up to 13%. It was significantly higher than that of the reference valves. This result suggested that paravalvular leakage had occurred in the tested valves. It was found in the further analysis that because HVPMIT was not sewn into the heart tissue when the HVPMIT was implanted in vivo and there was not a sewing ring in the HVPMIT, when tested valves were fixed in the pulse duplicator, some gaps might exist between the stent of HVPMIT and the fix gasket, and the paravalvular leakage could therefore take place through these gaps. This study demonstrated that there are significant differences in the shape, structure, fixation in vivo and clinical operational methods between HVPMIT and original biological heart valve prostheses. It is necessary to establish new test methods which adapt for HVPMIT to evaluate its pulsatile-flow performance according to its own features. PMID:23488159

  18. Use of Circular Foldable Nitinol Blades for Resecting Calcified Aortic Heart Valves

    Science.gov (United States)

    Hauck, Florian; Wendt, Daniel; Stühle, Sebastian; Kawa, Emilia; Wendt, Hermann; Müller, Wiebke; Thielmann, Matthias; Kipfmüller, Brigitte; Vogel, Bernd; Jakob, Heinz

    2009-08-01

    The use of percutaneous aortic valve implantation is limited, as the native calcified valve is left in situ. A new device has been developed for resecting calcified aortic valves, using collapsible nickel-titanium blades: laser-cut T-structures of Nitinol sheet-material (Ni51Ti49 at.%) have been grinded on a high-speed milling cutter to produce cutting edges which have been given the shape of half-circles afterwards. These have been connected to each other and to struts by using rivets which also serve as articulating axes for the cutting ring. The blades are folded around these axes and retreated into a tube to be inserted in the heart through the calcified valve leaflets. Once released, the cutting edges regain their ring-shape. By combining rotation of the ring with a translating movement against a second ring of slightly greater diameter on the instrument, a punching process is created which cuts the calcified valve leaflets and leaves a circular annulus, where a prosthesis can be fixed. In vitro cutting of artificially calcified valves ( n = 6) resulted in a resection time of t = 22 ± 6.29 s with a maximum turning moment of M = 2.4 ± 1.27 Nm, proving the function and the feasibility of the concept.

  19. Measurement of pulsatile turbulent flow downstream of polyurethane heart valve prosthesis using particle image velocimetry

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J.K.; Sung, J.Y. [Graduate School, Seoul National University, Seoul (Korea); Chang, J.K.; Min, B.G.; Yoo, J.Y. [Seoul National University, Seoul (Korea)

    1998-11-01

    In-vitro flow characteristics downstream of a polyurethane artificial heart valve under a pulsatile flow condition were investigated using Particle Image Velocimetry (PIV). With a triggering system and a time-delay circuit the velocity field downstream of the valve was evaluated in conjunction with the opening behavior of a flexible valve leaflet during a cardiac cycle.. Reynolds shear stress distribution was calculated from the velocity fields at a peak systolic phase. Direct measurements of the wall shear stress by hot-film anemometry (HFA) were compared with the PIV data. The possibilities of vascular complications, such as the thrombus formation and red blood cell damage, could be estimated from the overall view of the instantaneous velocity and stress fields obtained. A correlation between the flow pattern downstream of the valve and the corresponding opening posture of the polyurethane valve membrane gives useful data necessary for the improved design of the frame structure and leaflet geometry of the valve. (author). 11 refs., 8 figs., 5 tabs.

  20. 儿童人工心脏瓣膜置换术%Heart Valve Replacement in Children

    Institute of Scientific and Technical Information of China (English)

    张镜芳; 陈伟达; 罗征祥; 蔡增欣; 何竞功; 吴若彬; 肖学钧

    1993-01-01

    This article chronicles the experience in treating 37 patients (male 22,female 15.aged 4.5 to 14 yrs)with congenital heart disease (17),rheumatic heart disease(15),congenital and rheumatic (1) and subacute bacterial endocarditis (4).The cardiac function before valve prosthesis replacement was grade Ⅳ in 15,Ⅲ in 13,Ⅱ in 7and Ⅰ in Ⅰ.Of them,25 underwent mitral valve replacement (MVR) and 10 tricupid valve replacement (TVR).Sixteen cases were inserted on biovalve,21 cases on mechanical valve prosthesis.The cardiac function of 13 survivors has been improved with a followed-up of 185 months.The hospital mortality was 24.3%.The indications of MVR are:(1) severe mitral insufficiency with cardiac function of grade Ⅲ or Ⅳ.(2)cardiothoracic ratio of more than 0.6 and (3) an irretrievable mitral valve.If the symptoms of myocadiai ischemia of aortic valvular lesion are obvious,AVR should be considered.The authors suggest that cardiac valve replacement be used prudently,only for patients failing to show improvement after conventional treatment.The mechanical valve prosthesis is the first choice for the left heart lesions and the biovalve is suitable for the right heart.In our series,no one presents symptoms of the growth inconformity with the valve prosthesis.%1975~1991年间,对14岁以下患有心脏瓣膜病变的儿童置换人工心脏瓣膜37例.16例使用生物瓣,21例使用机械瓣.住院死亡9例,术后失随访4例,晚期死亡11例,长期存活13例,已随访6~185个月,其中心功能Ⅰ级11例,Ⅱ级2例,无1例因生长发育出现人工瓣膜相对狭窄.儿童人工心脏瓣膜置换术的适应证宜慎重,只有当内科及外科治疗(如瓣膜整形术)无效时才考虑.儿童左心置换瓣膜应首选机械瓣,生物瓣适用于右心.

  1. LLNL heart valve condition classification project anechoic testing results at the TRANSDEC evaluation facility

    Energy Technology Data Exchange (ETDEWEB)

    Candy, J V

    1999-10-31

    This report first briefly outlines the procedures and support/activation fixture developed at LLNL to perform the heart valve tests in an anechoic-like tank at the US Navy Transducer Evaluation Facility (TransDec) located in San Diego, CA. Next they discuss the basic experiments performed and the corresponding experimental plan employed to gather meaningful data systematically. The signal processing required to extract the desired information is briefly developed along with some of the data. Finally, they show the results of the individual runs for each valve, point out any of the meaningful features and summaries.

  2. Decellularized allogeneic heart valves demonstrate self-regeneration potential after a long-term preclinical evaluation.

    Science.gov (United States)

    Iop, Laura; Bonetti, Antonella; Naso, Filippo; Rizzo, Stefania; Cagnin, Stefano; Bianco, Roberto; Dal Lin, Carlo; Martini, Paolo; Poser, Helen; Franci, Paolo; Lanfranchi, Gerolamo; Busetto, Roberto; Spina, Michel; Basso, Cristina; Marchini, Maurizio; Gandaglia, Alessandro; Ortolani, Fulvia; Gerosa, Gino

    2014-01-01

    Tissue-engineered heart valves are proposed as novel viable replacements granting longer durability and growth potential. However, they require extensive in vitro cell-conditioning in bioreactor before implantation. Here, the propensity of non-preconditioned decellularized heart valves to spontaneous in body self-regeneration was investigated in a large animal model. Decellularized porcine aortic valves were evaluated for right ventricular outflow tract (RVOT) reconstruction in Vietnamese Pigs (n = 11) with 6 (n = 5) and 15 (n = 6) follow-up months. Repositioned native valves (n = 2 for each time) were considered as control. Tissue and cell components from explanted valves were investigated by histology, immunohistochemistry, electron microscopy, and gene expression. Most substitutes constantly demonstrated in vivo adequate hemodynamic performances and ex vivo progressive repopulation during the 15 implantation months without signs of calcifications, fibrosis and/or thrombosis, as revealed by histological, immunohistochemical, ultrastructural, metabolic and transcriptomic profiles. Colonizing cells displayed native-like phenotypes and actively synthesized novel extracellular matrix elements, as collagen and elastin fibers. New mature blood vessels, i.e. capillaries and vasa vasorum, were identified in repopulated valves especially in the medial and adventitial tunicae of regenerated arterial walls. Such findings correlated to the up-regulated vascular gene transcription. Neoinnervation hallmarks were appreciated at histological and ultrastructural levels. Macrophage populations with reparative M2 phenotype were highly represented in repopulated valves. Indeed, no aspects of adverse/immune reaction were revealed in immunohistochemical and transcriptomic patterns. Among differentiated elements, several cells were identified expressing typical stem cell markers of embryonic, hematopoietic, neural and mesenchymal lineages in significantly higher number

  3. Decellularized allogeneic heart valves demonstrate self-regeneration potential after a long-term preclinical evaluation.

    Directory of Open Access Journals (Sweden)

    Laura Iop

    Full Text Available Tissue-engineered heart valves are proposed as novel viable replacements granting longer durability and growth potential. However, they require extensive in vitro cell-conditioning in bioreactor before implantation. Here, the propensity of non-preconditioned decellularized heart valves to spontaneous in body self-regeneration was investigated in a large animal model. Decellularized porcine aortic valves were evaluated for right ventricular outflow tract (RVOT reconstruction in Vietnamese Pigs (n = 11 with 6 (n = 5 and 15 (n = 6 follow-up months. Repositioned native valves (n = 2 for each time were considered as control. Tissue and cell components from explanted valves were investigated by histology, immunohistochemistry, electron microscopy, and gene expression. Most substitutes constantly demonstrated in vivo adequate hemodynamic performances and ex vivo progressive repopulation during the 15 implantation months without signs of calcifications, fibrosis and/or thrombosis, as revealed by histological, immunohistochemical, ultrastructural, metabolic and transcriptomic profiles. Colonizing cells displayed native-like phenotypes and actively synthesized novel extracellular matrix elements, as collagen and elastin fibers. New mature blood vessels, i.e. capillaries and vasa vasorum, were identified in repopulated valves especially in the medial and adventitial tunicae of regenerated arterial walls. Such findings correlated to the up-regulated vascular gene transcription. Neoinnervation hallmarks were appreciated at histological and ultrastructural levels. Macrophage populations with reparative M2 phenotype were highly represented in repopulated valves. Indeed, no aspects of adverse/immune reaction were revealed in immunohistochemical and transcriptomic patterns. Among differentiated elements, several cells were identified expressing typical stem cell markers of embryonic, hematopoietic, neural and mesenchymal lineages in significantly

  4. Scedosporium apiosermum infection of the “Native” valve: Fungal endocarditis in an orthotopic heart transplant recipient

    OpenAIRE

    Clement, Meredith E.; Eileen K. Maziarz; Schroder, Jacob N.; Patel, Chetan B.; Perfect, John R.

    2015-01-01

    Scedosporium apiospermum is an increasingly appreciated pathogen in immunosuppressed patients. We present a case of S. apiospermum endocarditis in a 70-year-old male who had undergone orthotopic heart transplant. Echocardiogram demonstrated a 1.4 cm tricuspid valve vegetation. He underwent valve replacement, complicated by fatal massive post-operative haemorrhage. Valve cultures grew S. apiospermum. To our knowledge, our case is the first reported instance of endocarditis caused by S. apiospe...

  5. Multi-scale mechanical characterization of scaffolds for heart valve tissue engineering.

    Science.gov (United States)

    Argento, G; Simonet, M; Oomens, C W J; Baaijens, F P T

    2012-11-15

    Electrospinning is a promising technology to produce scaffolds for cardiovascular tissue engineering. Each electrospun scaffold is characterized by a complex micro-scale structure that is responsible for its macroscopic mechanical behavior. In this study, we focus on the development and the validation of a computational micro-scale model that takes into account the structural features of the electrospun material, and is suitable for studying the multi-scale scaffold mechanics. We show that the computational tool developed is able to describe and predict the mechanical behavior of electrospun scaffolds characterized by different microstructures. Moreover, we explore the global mechanical properties of valve-shaped scaffolds with different microstructural features, and compare the deformation of these scaffolds when submitted to diastolic pressures with a tissue engineered and a native valve. It is shown that a pronounced degree of anisotropy is necessary to reproduce the deformation patterns observed in the native heart valve.

  6. Rapid manufacturing techniques for the tissue engineering of human heart valves.

    Science.gov (United States)

    Lueders, Cora; Jastram, Ben; Hetzer, Roland; Schwandt, Hartmut

    2014-10-01

    Three-dimensional (3D) printing technologies have reached a level of quality that justifies considering rapid manufacturing for medical applications. Herein, we introduce a new approach using 3D printing to simplify and improve the fabrication of human heart valve scaffolds by tissue engineering (TE). Custom-made human heart valve scaffolds are to be fabricated on a selective laser-sintering 3D printer for subsequent seeding with vascular cells from human umbilical cords. The scaffolds will be produced from resorbable polymers that must feature a number of specific properties: the structure, i.e. particle granularity and shape, and thermic properties must be feasible for the printing process. They must be suitable for the cell-seeding process and at the same time should be resorbable. They must be applicable for implementation in the human body and flexible enough to support the full functionality of the valve. The research focuses mainly on the search for a suitable scaffold material that allows the implementation of both the printing process to produce the scaffolds and the cell-seeding process, while meeting all of the above requirements. Computer tomographic data from patients were transformed into a 3D data model suitable for the 3D printer. Our current activities involve various aspects of the printing process, material research and the implementation of the cell-seeding process. Different resorbable polymeric materials have been examined and used to fabricate heart valve scaffolds by rapid manufacturing. Human vascular cells attached to the scaffold surface should migrate additionally into the inner structure of the polymeric samples. The ultimate intention of our approach is to establish a heart valve fabrication process based on 3D rapid manufacturing and TE. Based on the computer tomographic data of a patient, a custom-made scaffold for a valve will be produced on a 3D printer and populated preferably by autologous cells. The long-term goal is to support

  7. St. Jude Medical and CarboMedics Mechanical Heart Valves in the Aortic Position: Comparison of Long-Term Results

    OpenAIRE

    Kandemir, Ozer; Tokmakoglu, Hilmi; Yildiz, Ulku; TEZCANER, Tevfik; Yorgancioglu, A. Cem; Gunay, Ilhan; Suzer, Kaya; Zorlutuna, Yaman

    2006-01-01

    We designed this study to compare long-term results of St. Jude Medical and CarboMedics mechanical heart valves in the aortic position. We retrospectively analyzed the results of 174 consecutive patients who received either a St. Jude (n=80) or a CarboMedics (n=94) mechanical aortic valve from March 1992 through October 2004.

  8. Prospective ECG triggering reduces prosthetic heart valve-induced artefacts compared with retrospective ECG gating on 256-slice CT.

    NARCIS (Netherlands)

    Symersky, P.; Habets, J.; Westers, P.; Mol, B.A. de; Prokop, M.; Budde, R.P.

    2012-01-01

    OBJECTIVES: Multidetector computed tomography (MDCT) has diagnostic value for the evaluation of prosthetic heart valve (PHV) dysfunction but it is hampered by artefacts. We hypothesised that image acquisition using prospective triggering instead of retrospective gating would reduce artefacts related

  9. Analysis of risk factors for valve replacements in 5128 cases from a single heart center in China

    Institute of Scientific and Technical Information of China (English)

    GUO Li-xin; MENG Xu; ZHANG Zhao-guang; BAI Tao

    2010-01-01

    Background Numerous studies have developed a "severity score" or "risk index" for short-term mortality associated with coronary artery bypass grafting (CABG). Due to the different distribution of disease types, the number of valve surgeries in the US and Europe is relatively small. Thus, a risk-scoring system for valve surgeries was developed later and used less than that for the CABG surgery. We retrospectively reviewed 5128 cases of heart valve replacement, to quantitatively assess the risk factors for hospital mortality, and establish risk models for the hospital mortality of cardiac valve replacement patients.Methods A total of 1549 cases of aortic valve replacement, 2460 cases of mitral valve replacement, and 1119 cases of combined aortic valve and mitral valve replacement that were recorded from January 2005 to December 2009 in the cardiac surgery database at Beijing Anzhen Hospital were selected for this study. The cases were randomly assigned to a indicators were selected as possible influencing factors for hospital mortality. Single-factor analysis was performed to screen these factors, and then multi-factor analysis was used to determine the risk factors for hospital mortality in the three surgeries and to establish risk models.Results In the multi-factor analysis, age, body surface area, etiology, cardiopulmonary bypass time, preoperative cardiothoracic ratio, cardiac functional classification, and preoperative creatinine were risk factors for aortic valve replacement. Etiology, preoperative history of heart failure, cardiopulmonary bypass time, preoperative cardiothoracic ratio, and preoperative left ventricular end systolic diameter were risk factors for mitral valve replacement. Age, body mass index, cardiopulmonary bypass time, and cardiac function classification were risk factors for combined aortic valve and mitral valve replacement. The risk models showed good predictive ability (Hosmer-Lemeshow test: P=0.981 in the model for aortic valve

  10. Gamma radiation and its role in bio prosthetic aortic valves implanted in rat hearts

    International Nuclear Information System (INIS)

    Porcine heart valves glutaraldehyde fixed are implanted in patients with valvular deterioration. Mineralization may be the major factor in the long-term failure of tissue bio prosthesis. Gamma radiation randomly breaks some glutaraldehyde cross-links. As a consequence of irradiation, the polymeric fibers belonging to the valvular tissue are broken too, leading to sites of collagen fiber disorganisation. It is well known that the collagen fibers may act as a passive nucleator of salts where the calcium phosphate salts precipitate. This salt concentration has been described in association with disintegrated sites of protein fiber, which may favour new sites where the calcium salts would be deposit. The irradiation process is a technique used for sterilization of porcine heart valve. The main objective of this work was to study the effect of different doses of gamma radiation on the calcification process of subcutaneously implanted valves in rats. Small pieces from glutaraldehyde fixed valves, irradiated to different doses with a 60Co sources were implanted subcutaneously in rats. The calcium was measured by X-ray and atomic absorption spectrophotometry. In our experimental conditions and at the radiation doses used in these tests, the calcium measurements on control and irradiated material were not significantly different. We conclude that, at the employed doses, the gamma radiation does not alter the process. (author)

  11. SURGICAL CORRECTION OF HEART VALVE DISEASE WITH CARDIOPULMONARY BYPASS IN PATIENTS AFTER RENAL TRANSPLANTATION

    Directory of Open Access Journals (Sweden)

    D. A. Belokurov

    2013-01-01

    Full Text Available Aim. Evaluation of the possibility heart valve replacement in renal transplant recipients from a position of safe- ty for graft function. Materials and methods. 5 patients, heart valve replacement was performed with a func- tioning kidney transplant at a satisfactory its function. The average age of patients at the time of cardiac surgery was 38,8 ± 12,6 years, among whom were two (40% men and 3 (60% women. The interval between renal transplantation and heart surgery was 40,3 ± 44,1 (2 to 120 months. Prior to kidney transplantation, all patients were on renal replacement therapy with hemodialysis program for 50,2 ± 48,6 months. In 4 of the 5 patients of heart disease was the cause of infective endocarditis. Results. Average time IR was 81,2 ± 21,7 minutes , the average time of aortic clamping 63,6 ± 20,9 minutes and hypothermia during CPB 29,2 ± 3,2 °C. All patients were implanted with double-leaf mechanical prostheses "MedEng-2" and "SarboMedics". All 5 patients in sa- tisfactory condition were discharged from the hospital. The average duration of the postoperative period was 14,2 ± 3,4 days. All patients had relatively smooth flow after surgery, no infectious complications, a satisfactory renal transplant function and prosthetic heart valves. In the late period in four patients and transplant graft func- tion is satisfactory in terms of the observation of 5 years, 3 years and 6 months after surgery. Conclusion. Our experience shows the possibility of successful correction of heart defects in IR in renal transplant recipients. 

  12. Mitigation of Shear-Induced Blood Damage of Mechanical Bileaflet Heart Valves using Embedded Vortex Generators

    Science.gov (United States)

    Hidalgo, Pablo; Arjunon, Sivakkumar; Saikrishnan, Neelakantan; Yoganathan, Ajit; Glezer, Ari

    2012-11-01

    The strong transitory shear stress generated during the time-periodic closing of the mechanical prosthetic bileaflet aortic heart valve, is considered to be one of the main factors responsible for complications, associated with thrombosis and thromboembolism. These flow transients are investigated using phase and time-averaged PIV in a low-volume (about 150 ml) test setup that simulates the pulsatile physiological conditions associated with a 23 mm St. Jude Medical valve. The PIV measurements are accompanied by continuous monitoring of the ventricular and aortic pressures and valve flow rate. Following the valve closure, the leakage flow between the valve leaflets is caused by the pressure buildup across the leaflets, leading to the formation of a regurgitation jet starting from the BMHV B-datum line. As in a typical starting jet, a counter-rotating vortex pair is formed along each leaflet edge and the vorticity sheet is associated with high shear stress that may be result in blood platelet activation. The present investigation demonstrates that the placement of arrays of mm-scale vortex generators near the edges of the leaflets diffuses the vortex sheet and suppresses the formation of these vortices, weakening the local velocity gradients and small-scale vortical structures. Supported by NIH and NSF.

  13. Right ventricular Hemodynamic Alteration after Pulmonary Valve Replacement in Children with Congenital Heart Disease

    Directory of Open Access Journals (Sweden)

    Hamid Bigdelian

    2015-03-01

    Full Text Available Introduction:  In patients who underwent surgery to repair Tetralogy of Fallot, right ventricular dilation from pulmonary regurgitation may be result in right ventricular failure, arrhythmias and cardiac arrest. Hence, pulmonary valve replacement may be necessary to reduce right ventricular volume overload. The aim of present study was to assess the effects of pulmonary valve replacement on right ventricular function after repair of Tetralogy of Fallot.   Materials and  Method:  This retrospective study was carried out between July 2011 and October 2013 on 21 consecutive patients in Chamran Heart Center (Esfahan. The study included 13 male (61.9% and 8 female (38.1%. Cardiac magnetic resonance was performed before, 6 and 12 months after pulmonary valve replacement in all patients (Babak Imaging Center, Tehran with the 1.5 Tesla system. The main reason for surgery at Tetralogy of Fallot repaired time was Tetralogy of Fallot + Pulmonary insufficiency (17 cases and Tetralogy of Fallot + Pulmonary atresia (4 cases. Right ventricular function was assessed before and after pulmonary valve replacement with Two-dimensional echocardiography and ttest was used to evaluate follow-up data.   Results:  Right ventricular end-diastolic volume, right ventricular end- systolic volume significantly decreased (P value ˂ 0.05.Right ventricular ejection fraction had a significant increase (P value ˂ 0.05. Right ventricular mass substantially shrank after pulmonary valve replacement. Moreover, pulmonary regurgitation noticeably decreased in patients. The other hemodynamic parameter such as left ventricular ejection fraction improved but was not significant (P value= 0.79. Conclusion:  Pulmonary valve replacement can successfully restores the impaired hemodynamic function of right ventricle which is caused by direct consequence of volume unloading in patient. Pulmonary valve surgery in children with Tetralogy of Fallot who have moderate to severe pulmonary

  14. Impact of Detergent-Based Decellularization Methods on Porcine Tissues for Heart Valve Engineering.

    Science.gov (United States)

    Roosens, Annelies; Somers, Pamela; De Somer, Filip; Carriel, Victor; Van Nooten, Guido; Cornelissen, Ria

    2016-09-01

    To date an optimal decellularization protocol of heart valve leaflets (HVL) and pericardia (PER) with an adequate preservation of the extracellular matrix (ECM) is still lacking. This study compares a 4 day Triton X-100-based protocol with faster SDC-based protocols for the decellularization of cardiac tissues. Decellularized and non-treated HVL and PER were processed for histological, biochemical and mechanical analysis to determine the effect of these agents on the structure, ECM components, and biomechanical properties. Tissues treated with SDC-based protocols still showed nuclear material, whereas tissues treated with Triton X-100 1% + ENZ ± TRYP were completely cell free. For both decellularized tissues, an almost complete washout of glycosaminoglycans, a reduction of soluble collagen and an alteration of the surface ultrastructure was observed. Interestingly, only the elastic fibers of pericardial tissue were affected and this tissue had a decreased maximum load. This study showed that both detergents had a similar impact on the ECM. However, Triton X-100 1% +DNase/RNase (ENZ) ± Trypsin (TRYP) is the only protocol that generated completely cell free bioscaffolds. Also, our study clearly demonstrated that the decellularization agents have more impact on pericardial tissues than on heart valve leaflets. Thus, for the purpose of tissue engineering of heart valves, it is advisable to use valvular rather than pericardial matrices. PMID:26842626

  15. Research on micro-structure and hemo-compatibility of the artificial heart valve surface

    International Nuclear Information System (INIS)

    In order to seek the method to improve the hemo-compatibility of artificial mechanical heart valve, the surface of rabbit's heart valve was observed using the scanning electron microscopy (SEM). The results showed that the dual-scale structure which consists of cobblestones-like structure of 8 μm in underside diameter and 3 μm in height, and the fine cilia of about 150 nm in diameter, was helpful to the hemo-compatibility of the heart valve. Therefore, the polydimethylsiloxane (PDMS) surface with hierarchical micro-structure was fabricated using femtosecond laser fabrication technique and soft lithography. At the same time, the tests of apparent contact angle and platelet adhesion on both smooth and textured PDMS surfaces were carried out to study their wettability and hemo-compatibility. The results demonstrated that the surface with textured structure displayed more excellent wettabililty and anti-coagulation property than that of smooth surface. The apparent contact angle of textured surface enhanced from 113.1 deg. to 163.6 deg. and the amount of adsorbed platelet on such surface was fewer, no distortion and no activation were found.

  16. Right heart chamber geometry and tricuspid annulus morphology in patients undergoing mitral valve repair with and without tricuspid valve annuloplasty.

    Science.gov (United States)

    Tamborini, Gloria; Fusini, Laura; Muratori, Manuela; Gripari, Paola; Ghulam Ali, Sarah; Fiorentini, Cesare; Pepi, Mauro

    2016-06-01

    According to current recommendations, patients could benefit from tricuspid valve (TV) annuloplasty at the time mitral valve (MV) surgery if tricuspid regurgitation is severe or if tricuspid annulus (TA) dilatation is present. Therefore, an accurate pre-operative echocardiographic study is mandatory for left but also for right cardiac structures. Aims of this study are to assess right atrial (RA), right ventricular (RV) and TA geometry and function in patients undergoing MV repair without or with TV annuloplasty. We studied 103 patients undergoing MV surgery without (G1: 54 cases) or with (G2: 49 cases) concomitant TV annuloplasty and 40 healthy subjects (NL) as controls. RA, RV and TA were evaluated by three-dimensional (3D) transthoracic echocardiography. Comparing the pathological to the NL group, TA parameters and 3D right chamber volumes were significantly larger. RA and RV ejection fraction and TA% reduction were lower in pathological versus NL, and in G2 versus G1. In pathological patients, TA area positively correlated to systolic pulmonary pressure and negatively with RV and RA ejection fraction. Patients undergoing MV surgery and TV annuloplasty had an increased TA dimensions and a more advanced remodeling of right heart chambers probably reflecting an advanced stage of the disease. PMID:26820739

  17. Age-Dependent Changes in Geometry, Tissue Composition and Mechanical Properties of Fetal to Adult Cryopreserved Human Heart Valves.

    Science.gov (United States)

    van Geemen, Daphne; Soares, Ana L F; Oomen, Pim J A; Driessen-Mol, Anita; Janssen-van den Broek, Marloes W J T; van den Bogaerdt, Antoon J; Bogers, Ad J J C; Goumans, Marie-José T H; Baaijens, Frank P T; Bouten, Carlijn V C

    2016-01-01

    There is limited information about age-specific structural and functional properties of human heart valves, while this information is key to the development and evaluation of living valve replacements for pediatric and adolescent patients. Here, we present an extended data set of structure-function properties of cryopreserved human pulmonary and aortic heart valves, providing age-specific information for living valve replacements. Tissue composition, morphology, mechanical properties, and maturation of leaflets from 16 pairs of structurally unaffected aortic and pulmonary valves of human donors (fetal-53 years) were analyzed. Interestingly, no major differences were observed between the aortic and pulmonary valves. Valve annulus and leaflet dimensions increase throughout life. The typical three-layered leaflet structure is present before birth, but becomes more distinct with age. After birth, cell numbers decrease rapidly, while remaining cells obtain a quiescent phenotype and reside in the ventricularis and spongiosa. With age and maturation-but more pronounced in aortic valves-the matrix shows an increasing amount of collagen and collagen cross-links and a reduction in glycosaminoglycans. These matrix changes correlate with increasing leaflet stiffness with age. Our data provide a new and comprehensive overview of the changes of structure-function properties of fetal to adult human semilunar heart valves that can be used to evaluate and optimize future therapies, such as tissue engineering of heart valves. Changing hemodynamic conditions with age can explain initial changes in matrix composition and consequent mechanical properties, but cannot explain the ongoing changes in valve dimensions and matrix composition at older age.

  18. Multidetector CT imaging of mechanical prosthetic heart valves: quantification of artifacts with a pulsatile in-vitro model

    OpenAIRE

    Symersky, P.; Budde, R. P. J.; Westers, P.; Mol, de, B.A.J.M.; Prokop, M

    2011-01-01

    Objectives Multidetector computed tomography (MDCT) can detect the cause of prosthetic heart valve (PHV) dysfunction but is hampered by valve-induced artifacts. We quantified artifacts of four PHV using a pulsatile in-vitro model and assessed the relation to leaflet motion and valve design. Methods A Medtronic Hall tilting disc (MH), and Carbomedics (CM), St Jude (SJM), and ON-X bileaflet valves underwent CT in an in-vitro model using retrospective gating with a 64 detector CT system in stati...

  19. Double Valve Replacement (Mitral and Aortic for Rheumatic Heart Disease: A 20-year experience with 300 patients.

    Directory of Open Access Journals (Sweden)

    Prashant Mishra

    2016-09-01

    Full Text Available Introduction: Rheumatic heart disease still remains one of the leading causes of congestive heart failure and death owing to valvular pathologies, in developing countries. Valve replacement still remains the treatment of choice in such patients.The aim of this study wasto analyze the postoperative outcome of  double valve replacement (Mitral and Aortic in patients of rheumatic heart disease. Materials and Methods: Between 1988 and 2008, 300 patients of rheumatic heart disease underwent double (Mitral and Aortic valve replacement with Starr Edwards valve or St Jude mechanical valve prosthesis were implanted. These patients were studied retrospectively for preoperative data and postoperative outcome including causes of early and late deaths and the data was analyzed statistically. Results: The 30-day hospital death rate was 11.3% andlate death occurred in 11.6%. Anticoagulant regimen was followed to maintain the target pro-thrombin time at 1.5 times the control value. The actuarial survival (exclusive of hospital mortality was 92.4%, 84.6%, and 84.4%, per year at 5, 10, and 20 years, respectively Conclusions: In view of the acknowledged advantageof superior durability, increased thromboresistance in our patient population, and its cost effectiveness the Starr-Edwards ball valve or St. Jude valve is the mechanical prosthesis of choice for advanced combined valvular disease. The low-intensity anticoagulant regimen has offered suffcient protection against thromboembolism as well as hemorrhage.

  20. Evaluation of a transient, simultaneous, arbitrary Lagrange-Euler based multi-physics method for simulating the mitral heart valve.

    Science.gov (United States)

    Espino, Daniel M; Shepherd, Duncan E T; Hukins, David W L

    2014-01-01

    A transient multi-physics model of the mitral heart valve has been developed, which allows simultaneous calculation of fluid flow and structural deformation. A recently developed contact method has been applied to enable simulation of systole (the stage when blood pressure is elevated within the heart to pump blood to the body). The geometry was simplified to represent the mitral valve within the heart walls in two dimensions. Only the mitral valve undergoes deformation. A moving arbitrary Lagrange-Euler mesh is used to allow true fluid-structure interaction (FSI). The FSI model requires blood flow to induce valve closure by inducing strains in the region of 10-20%. Model predictions were found to be consistent with existing literature and will undergo further development.

  1. Effect of vortex generators on the closing transient flow of bileaflet mechanical heart valves

    Science.gov (United States)

    Murphy, David; Dasi, Lakshmi; Yoganathan, Ajit; Glezer, Ari

    2006-11-01

    The time-periodic closing of bileaflet mechanical heart valves is accompanied by a strong flow transient that is associated with the formation of a counter-rotating vortex pair near the b-datum line of leaflet edges. The strong transitory shear that is generated by these vortices may be damaging to blood elements and may result in platelet activation. In the present work, these flow transients are mitigated using miniature vortex generator arrays that are embedded on the surface of the leaflets. Two vortex generator designs were investigated: one design comprised staggered rectangular fins and the other one staggered hemispheres. The closing transients in the absence and presence of the passive vortex generators are characterized using phase locked PIV measurements. The study utilizes a 25 mm St. Jude Medical valve placed in the aortic position of the Georgia Tech left heart simulator. Measurements of the velocity field in the center plane of the leaflets demonstrate that the dynamics of the transient vortices that precede the formation of the leakage jets can be significantly altered and controlled by relatively simple passive modifications of existing valve designs. Human blood experiments validated the effectiveness of miniature vortex generators in reducing thrombus formation by over 42 percent.

  2. Neomycin enhances extracellular matrix stability of glutaraldehyde crosslinked bioprosthetic heart valves.

    Science.gov (United States)

    Friebe, Vincent M; Mikulis, Brandon; Kole, Sourav; Ruffing, Christy S; Sacks, Michael S; Vyavahare, Naren R

    2011-11-01

    Glutaraldehyde (GLUT) crosslinked porcine aortic heart valves are continued to be extensively used in heart valve replacement surgeries. GLUT does not crosslink glycosaminoglycans in the tissue and we have demonstrated that GAG loss is associated with tissue degeneration. In this study, we examined the ability of neomycin to enhance GLUT crosslinking to stabilize GAGs, as well as provide evidence of improved functional integrity. Neomycin enhanced GLUT crosslinked (NG) leaflets exposed to collagenase and elastase enzymes exhibited an increased resistance to proteolytic degradation. Furthermore, NG leaflets exhibited small but significant increases in collagen denaturation temperatures when compared to that of standard GLUT crosslinked BHVs. NG leaflets subjected to storage, accelerated cyclic fatigue, and in vitro enzyme mediated GAG degradation revealed improved GAG stabilization versus standard GLUT crosslinked valves, which sustained substantial decreases in GAG content. Ultrastructural analysis using transmission electron microscopy qualitatively confirmed NG leaflets preserved GAGs after enzymatic degradation. Biomechanical analyses demonstrated that NG leaflets were functionally similar to GLUT tissues but were slightly stiffer under both planar biaxial tension and under flexure. Interestingly, after GAGase treatment, GLUT tissues showed increased areal compliance and reduced hysteresis, while NG leaflets were unchanged. Collectively, NG cross-linking functionally insulated the tissue from GAG digestion, and imparted modest additional matrix stiffness but maintained tissue hysteresis properties.

  3. Heart valve surgery in hemodialysis-dependent patients: nutrition status impact on surgical outcome.

    Science.gov (United States)

    Kawahito, Koji; Aizawa, Kei; Oki, Shinichi; Saito, Tsutomu; Misawa, Yoshio

    2016-06-01

    Valve surgery in hemodialysis-dependent patients is associated with postoperative complications and a high mortality rate, and such patients frequently suffer cachexia. This study aimed to determine pre- and intraoperative risk factors associated with in-hospital mortality and long-term survival in hemodialysis-dependent patients undergoing heart valve surgery from the viewpoint of nutrition status. Eighty-seven hemodialysis-dependent patients who underwent valve surgery between January 1998 and October 2015 were retrospectively reviewed. Thirty-seven potential perioperative risk factors were evaluated. The in-hospital mortality rate was 12.6 % (11 patients). Univariate analysis identified New York Heart Association Functional Classification III or IV, emaciation (body mass index 3000 ml as predictors of in-hospital death. Multivariate logistic regression analysis confirmed low serum albumin death. The 1- and 3-year actuarial survival rates were 64.9 ± 5.4 and 51.8 ± 5.8 %, respectively. Long-term survival estimated by log-rank test was negatively impacted by anemia (hemoglobin death. Hypoalbuminemia and emergent/urgent operation are strong predictors of in-hospital and remote death. Malnutrition before surgery should be considered for operative risk estimation, and adequate preoperative nutrition management may improve surgical outcomes for hemodialysis-dependent patients. PMID:26749145

  4. Bioreactor Conditioning for Accelerated Remodeling of Fibrin-Based Tissue Engineered Heart Valves

    Science.gov (United States)

    Schmidt, Jillian Beth

    Fibrin is a promising scaffold material for tissue engineered heart valves, as it is completely biological, allows for engineered matrix alignment, and is able to be degraded and replaced with collagen by entrapped cells. However, the initial fibrin matrix is mechanically weak, and extensive in vitro culture is required to create valves with sufficient mechanical strength and stiffness for in vivo function. Culture in bioreactor systems, which provide cyclic stretching and enhance nutrient transport, has been shown to increase collagen production by cells entrapped in a fibrin scaffold, accelerating strengthening of the tissue and reducing the required culture time. In the present work, steps were taken to improve bioreactor culture conditions with the goal of accelerating collagen production in fibrin-based tissue engineered heart valves using two approaches: (i) optimizing the cyclic stretching protocol and (ii) developing a novel bioreactor system that permits transmural and lumenal flow of culture medium for improved nutrient transport. The results indicated that incrementally increasing strain amplitude cyclic stretching with small, frequent increments in strain amplitude was optimal for collagen production in our system. In addition, proof of concept studies were performed in the novel bioreactor system and increased cellularity and collagen deposition near the lumenal surface of the tissue were observed.

  5. Numerical simulation of flow in mechanical heart valves: grid resolution and the assumption of flow symmetry.

    Science.gov (United States)

    Ge, Liang; Jones, S Casey; Sotiropoulos, Fotis; Healy, Timothy M; Yoganathan, Ajit P

    2003-10-01

    A numerical method is developed for simulating unsteady, 3-D, laminar flow through a bileaflet mechanical heart valve with the leaflets fixed. The method employs a dual-time-stepping artificial-compressibility approach together with overset (Chimera) grids and is second-order accurate in space and time. Calculations are carried out for the full 3-D valve geometry under steady inflow conditions on meshes with a total number of nodes ranging from 4 x 10(5) to 1.6 x 10(6). The computed results show that downstream of the leaflets the flow is dominated by two pairs of counter-rotating vortices, which originate on either side of the central orifice in the aortic sinus and rotate such that the common flow of each pair is directed away from the aortic wall. These vortices intensify with Reynolds number, and at a Reynolds number of approximately 1200 their complex interaction leads to the onset of unsteady flow and the break of symmetry with respect to both geometric planes of symmetry. Our results show the highly 3-D structure of the flow; question the validity of computationally expedient assumptions of flow symmetry; and demonstrate the need for highly resolved, fully 3-D simulations if computational fluid dynamics is to accurately predict the flow in prosthetic mechanical heart valves.

  6. A numerical investigation of blood damage in the hinge area of bileaflet mechanical heart valves

    Science.gov (United States)

    Yun, Min; Wu, Jingshu; Simon, Helene; Sotiropoulos, Fotis; Aidun, Cyrus; Yoganathan, Ajit

    2010-11-01

    Studies have shown that high shear stress and large recirculation regions have a strong impact on thromboembolic complications in Bileaflet mechanical heart valves (BMHV). This study quantitatively compares the hinge flow field and blood damage of the 23mm St. Jude Medical (SJM) regent with different hinge gap widths and the 23mm CarboMedics (CM) valves. The lattice-Boltzmann method with external boundary force (LBM-EBF) [Wu and Aidun, Int. J Num. Methods Fluids, 62, 7, 2009] was implemented to simulate the flow and capture the dynamics and the surface shear stress of the platelets with realistic geometry. The velocity boundary conditions for the small-scale hinge flow are obtained from previous 3D large-scale computational fluid dynamics (CFD) simulations [Simon et al, Annals of Biomedical Engineering, 38, 3, 2009]. The flow patterns of three hinges that were studied were similar during diastole. However, velocity magnitudes and shear stresses at the hinge gap were different, which may explain the higher blood damage index (BDI) value for the CM valve and lower BDI value for the SJM valve with a larger gap width. The multiscale computational method used to quantitatively measure the BDI during a full cardiac cycle will be discussed.

  7. Prediction of matrix-to-cell stress transfer in heart valve tissues.

    Science.gov (United States)

    Huang, Siyao; Huang, Hsiao-Ying Shadow

    2015-01-01

    Non-linear and anisotropic heart valve leaflet tissue mechanics manifest principally from the stratification, orientation, and inhomogeneity of their collagenous microstructures. Disturbance of the native collagen fiber network has clear consequences for valve and leaflet tissue mechanics and presumably, by virtue of their intimate embedment, on the valvular interstitial cell stress-strain state and concomitant phenotype. In the current study, a set of virtual biaxial stretch experiments were conducted on porcine pulmonary valve leaflet tissue photomicrographs via an image-based finite element approach. Stress distribution evolution during diastolic valve closure was predicted at both the tissue and cellular levels. Orthotropic material properties consistent with distinct stages of diastolic loading were applied. Virtual experiments predicted tissue- and cellular-level stress fields, providing insight into how matrix-to-cell stress transfer may be influenced by the inhomogeneous collagen fiber architecture, tissue anisotropic material properties, and the cellular distribution within the leaflet tissue. To the best of the authors' knowledge, this is the first study reporting on the evolution of stress fields at both the tissue and cellular levels in valvular tissue and thus contributes toward refining our collective understanding of valvular tissue micromechanics while providing a computational tool enabling the further study of valvular cell-matrix interactions.

  8. Mitral Valve Disease

    Science.gov (United States)

    ... Tricuspid Valve Disease Cardiac Rhythm Disturbances Thoracic Aortic Aneurysm Pediatric and Congenital Heart Disease Heart abnormalities that are ... Transplantation End-stage Lung Disease Adult Lung Transplantation Pediatric Lung ... Aortic Aneurysm Mitral Valve Disease Overview The mitral valve is ...

  9. Experimental investigations on the fluid-mechanics of an electrospun heart valve by means of particle image velocimetry.

    Science.gov (United States)

    Del Gaudio, Costantino; Gasbarroni, Pier Luca; Romano, Giovanni Paolo

    2016-12-01

    End-stage failing heart valves are currently replaced by mechanical or biological prostheses. Both types positively contribute to restore the physiological function of native valves, but a number of drawbacks limits the expected performances. In order to improve the outcome, tissue engineering can offer an alternative approach to design and fabricate innovative heart valves capable to support the requested function and to promote the formation of a novel, viable and correctly operating physiological structure. This potential result is particularly critical if referred to the aortic valve, being the one mainly exposed to structural and functional degeneration. In this regard, the here proposed study presents the fabrication and in vitro characterization of a bioresorbable electrospun heart valve prosthesis using the particle image velocimetry technique either in physiological and pathological fluid dynamic conditions. The scaffold was designed to reproduce the aortic valve geometry, also mimicking the fibrous structure of the natural extracellular matrix. To evaluate its performances for possible implantation, the flow fields downstream the valve were accurately investigated and compared. The experimental results showed a correct functionality of the device, supported by the formation of vortex structures at the edge of the three cusps, with Reynolds stress values below the threshold for the risk of hemolysis (which can be comprised in the range 400-4000N/m(2) depending on the exposure period), and a good structural resistance to the mechanical loads generated by the driving pressure difference.

  10. Mitigation of Shear-Induced Blood Damage by Mechanical Bileaflet Heart Valves

    Science.gov (United States)

    Zakharin, Boris; Arjunon, Sivakkumar; Saikrishnan, Neelakantan; Yoganathan, Ajit; Glezer, Ari

    2010-11-01

    The strong transitory shear stress generated during the time-periodic closing of bileaflet mechanical heart valves that is associated with the formation of counter-rotating vortices near the leaflet edges may be damaging to blood elements and may result in platelet activation and therefore thrombosis and thromboembolism complications. These flow transients are investigated using fluorescent PIV in a new, low-volume test setup that reproduces the pulsatile physiological conditions associated with a 25 mm St. Jude Medical valve. The flow transients are partially suppressed and the platelet activation is minimized using miniature vortex generator arrays that are embedded on the surface of the leaflets. Measurements of the ensuing flow taken phase-locked to the leaflet motion demonstrate substantial modification of the transient vertical structures and concomitant reduction of Reynolds shear stresses. Human blood experiments validated the effectiveness of miniature vortex generators in reducing thrombus formation by over 42 percent.

  11. Beating Heart Mitral Valve Replacement Surgery without Aortic Cross-Clamping via Right Thoracotomy in a Patient with Compromised Left Ventricular Functions

    Directory of Open Access Journals (Sweden)

    Ahmet Baris-Durukan

    2015-10-01

    Full Text Available Global myocardial ischemia and ischemia-reperfusion injury are potential adverse events related with cardioplegic arrest. Beating heart surgery has avoided such complications and adapted to valve surgery following successful results published on myocardial revascularization. Difficulty in weaning from cardiopulmonary bypass may be lessened by using on-pump beating heart surgery for mitral valve interventions. Here we describe a 64-year-old male patient with severe mitral regurgitation and dilated cardiomyopathy. Beating heart mitral valve replacement surgery was performed without aortic cross-clamping through a right thoracotomy approach. We believe that, particularly in patients with poor left ventricular functions, beating heart mitral valve surgery may be advantageous

  12. On-X Heart Valve Prosthesis: Numerical Simulation of Hemodynamic Performance in Accelerating Systole.

    Science.gov (United States)

    Mirkhani, Nima; Davoudi, Mohammad Reza; Hanafizadeh, Pedram; Javidi, Daryoosh; Saffarian, Niloofar

    2016-09-01

    Numerical simulation of the bileaflet mechanical heart valves (BMHVs) has been of interest for many researchers due to its capability of predicting hemodynamic performance. A lot of studies have tried to simulate this three-dimensional complex flow in order to analyze the effect of different valve designs on the blood flow pattern. However, simplified models and prescribed motion for the leaflets were utilized. In this paper, transient complex blood flow in the location of ascending aorta has been investigated in a realistic model by fully coupled simulation. Geometry model for the aorta and the replaced valve is constructed based on the medical images and extracted point clouds. A 23-mm On-X Medical BMHV as the new generation design has been selected for the flow field analysis. The two-way coupling simulation is conducted throughout the accelerating phase in order to obtain valve dynamics in the opening process. The complex flow field in the hinge recess is captured precisely for all leaflet positions and recirculating zones and elevated shear stress areas have been observed. Results indicate that On-X valve yields relatively less transvalvular pressure gradient which would lower cardiac external work. Furthermore, converging inlet leads to a more uniform flow and consequently less turbulent eddies. However, the leaflets cannot open fully due to middle diffuser-shaped orifice. In addition, asymmetric butterfly-shaped hinge design and converging orifice leads to better hemodynamic performance. With the help of two-way fluid solid interaction simulation, leaflet angle follows the experimental trends more precisely rather than the prescribed motion in previous 3D simulations. PMID:27164902

  13. Roentgenologic aspects of acute respiratory in sufficiency after heart valve prosthesis implantation

    International Nuclear Information System (INIS)

    Analysis of the X-ray findings in 156 patients with acute respiratory insufficiency (ART) in the immediate periods after implantation of heart valve prostheses has shown that various pulmonary complications, such as pulmonary edema (in 84% of cases), atelectasis, hypoventilation (5.1%), hemothorax (6.4%), pneumothorax (0.6%) were the prerequisites for the development of respiratory disorders. Pneumonias were not the primary cause of ART but an additional factor for the respiratory disorder progress, for they develop in the presence of previous pulmonary changes. The necessity and possibility of establishing the pathogenetic mechanism of pulmonary edema is shown

  14. Multidetector CT imaging of mechanical prosthetic heart valves: quantification of artifacts with a pulsatile in-vitro model

    Energy Technology Data Exchange (ETDEWEB)

    Symersky, Petr [Onze Lieve Vrouwe Gasthuis, Department of Cardiothoracic Surgery, Oosterpark 9, P.O box 95500, Amsterdam (Netherlands); Academic Medical Center, Department of Cardiothoracic Surgery, Amsterdam (Netherlands); Budde, Ricardo P.J. [University Medical Center, Department of Radiology, Utrecht (Netherlands); Westers, Paul [Julius Center for Health Sciences and Primary Care, Department of Biostatistics, Utrecht (Netherlands); Mol, Bas A.J.M. de [Academic Medical Center, Department of Cardiothoracic Surgery, Amsterdam (Netherlands); University of Technology Eindhoven, Department of Biomedical Engineering, Eindhoven (Netherlands); Prokop, Mathias [Radboud University Nijmegen Medical Center, Department of Radiology, Nijmegen (Netherlands)

    2011-10-15

    Multidetector computed tomography (MDCT) can detect the cause of prosthetic heart valve (PHV) dysfunction but is hampered by valve-induced artifacts. We quantified artifacts of four PHV using a pulsatile in-vitro model and assessed the relation to leaflet motion and valve design. A Medtronic Hall tilting disc (MH), and Carbomedics (CM), St Jude (SJM), and ON-X bileaflet valves underwent CT in an in-vitro model using retrospective gating with a 64 detector CT system in stationary and pulsatile conditions. Artifacts and radiopaque component volumes were quantified with thresholds based on surrounding structures and valvular components. Hypodense artifacts volumes (mm{sup 3}) were 1,029 {+-} 147, 535 {+-} 53, 371 {+-} 16, and 366 {+-} 18 for the SJM, MH, CM and ON-X valves (p < 0.001 except for the latter two valves p = 0.43). Hyperdense artifact volumes were 3,546 {+-} 141, 2,387 {+-} 103, 2,003 {+-} 102, and 3,033 {+-} 31 for the SJM, MH, CM and ON-X valve, respectively (all differences p < 0.001). Leaflet motion affected hypodense (F = 41.5, p < 0.001) and hyperdense artifacts (F = 53.7, p < 0.001). Closed and moving leaflets were associated with the least and the most artifacts respectively (p < 0.001, both artifact types). Both valve design and leaflet motion affect PHV-induced artifacts. Best imaging results may be expected for the CM valve during phases in which the leaflets are closed. (orig.)

  15. Blood Damage Through a Bileaflet Mechanical Heart Valve: A Quantitative Computational Study Using a Multiscale Suspension Flow Solver

    OpenAIRE

    Min Yun, B.; Aidun, Cyrus K.; Yoganathan, Ajit P.

    2014-01-01

    Bileaflet mechanical heart valves (BMHVs) are among the most popular prostheses to replace defective native valves. However, complex flow phenomena caused by the prosthesis are thought to induce serious thromboembolic complications. This study aims at employing a novel multiscale numerical method that models realistic sized suspended platelets for assessing blood damage potential in flow through BMHVs. A previously validated lattice-Boltzmann method (LBM) is used to simulate pulsatile flow th...

  16. Molecular Analysis of Oral Bacteria in Heart Valve of Patients With Cardiovascular Disease by Real-Time Polymerase Chain Reaction.

    Science.gov (United States)

    Oliveira, Francisco Artur Forte; Forte, Clarissa Pessoa Fernandes; Silva, Paulo Goberlânio de Barros; Lopes, Camile B; Montenegro, Raquel Carvalho; Santos, Ândrea Kely Campos Ribeiro Dos; Sobrinho, Carlos Roberto Martins Rodrigues; Mota, Mário Rogério Lima; Sousa, Fabrício Bitu; Alves, Ana Paula Negreiros Nunes

    2015-11-01

    Structural deficiencies and functional abnormalities of heart valves represent an important cause of cardiovascular morbidity and mortality, and a number of diseases, such as aortic stenosis, have been recently associated with infectious agents. This study aimed to analyze oral bacteria in dental plaque, saliva, and cardiac valves of patients with cardiovascular disease. Samples of supragingival plaque, subgingival plaque, saliva, and cardiac valve tissue were collected from 42 patients with heart valve disease. Molecular analysis of Streptococcus mutans, Prevotella intermedia, Porphyromonas gingivalis, and Treponema denticola was performed through real-time PCR. The micro-organism most frequently detected in heart valve samples was the S. mutans (89.3%), followed by P. intermedia (19.1%), P. gingivalis (4.2%), and T. denticola (2.1%). The mean decayed, missing, filled teeth (DMFT) was 26.4 ± 6.9 (mean ± SD), and according to the highest score of periodontal disease observed for each patient, periodontal pockets > 4 mm and dental calculus were detected in 43.4% and 34.7% of patients, respectively. In conclusion, oral bacteria, especially S. mutans, were found in the cardiac valve samples of patients with a high rate of caries and gingivitis/periodontitis. PMID:26632711

  17. Valve Replacement Performed on the Beating Heart with Continuous Retrograde Coronary Sinus Isothermic Blood Perfusion Combined with Coronary Bypass

    Directory of Open Access Journals (Sweden)

    Orhan Saim Demirtürk

    2012-12-01

    Full Text Available An operation on the beating heart was planned for a 60-year-old woman who applied to our clinic with aortic stenosis, three vessel coronary artery disease and poor left ventricular function. There are reports about beating heart valve surgery perfomed alone or combined with coronary artery bypass operations using continuous retrograde coronary sinus isothermic blood perfusion in patients with poor ventricle. We performed a coronary revascularization process for three-vessel disease on the pump beating heart and aortic valve replacement under cross-clamp using continuous retrograde coronary sinus isothermic blood perfusion in the same session. She was discharged on the sixth postoperative day after an uneventful recovery. She is well and active 24 months after the operation. Valve replacement using the retrograde coronary sinus isothermic blood perfusion technique due to its protective effect on the already borderline myocardial functions in patients with poor ventricles is a useful and clinically successful method.

  18. Computational Simulations of Flow Dynamics and Blood Damage Through a Bileaflet Mechanical Heart Valve Scaled to Pediatric Size and Flow

    OpenAIRE

    Yun, B. Min; McElhinney, Doff B.; Arjunon, Shiva; Mirabella, Lucia; Aidun, Cyrus K.; Yoganathan, Ajit P.

    2014-01-01

    Despite pressing needs, there are currently no FDA approved prosthetic valves available for use in the pediatric population. This study is performed for predictive assessment of blood damage in bileaflet mechanical heart valves (BMHVs) with pediatric sizing and flow conditions. A model of an adult-sized 23mm St. Jude Medical (SJM) Regent™ valve is selected for use in simulations, which is scaled in size for a 5-year old child and 6-month old infant. A previously validated lattice-Boltzmann me...

  19. Neomycin binding preserves extracellular matrix in bioprosthetic heart valves during in vitro cyclic fatigue and storage.

    Science.gov (United States)

    Raghavan, Devanathan; Starcher, Barry C; Vyavahare, Naren R

    2009-05-01

    Bioprosthetic heart valve (BHV) cusps have a complex architecture consisting of an anisotropic arrangement of collagen, glycosaminoglycans (GAGs) and elastin. Glutaraldehyde (GLUT) is used as a fixative for all clinical BHV implants; however, it only stabilizes the collagen component of the tissue, and other components such as GAGs and elastin are lost from the tissue during processing, storage or after implantation. We have shown previously that the effectiveness of the chemical crosslinking can be increased by incorporating neomycin trisulfate, a hyaluronidase inhibitor, to prevent the enzyme-mediated GAG degradation. In the present study, we optimized carbodiimide-based GAG-targeted chemistry to incorporate neomycin into BHV cusps prior to conventional GLUT crosslinking. This crosslinking leads to enhanced preservation of GAGs during in vitro cyclic fatigue and storage. The neomycin group showed greater GAG retention after both 10 and 50 million accelerated fatigue cycles and after 1 year of storage in GLUT solution. Thus, additional binding of neomycin to the cusps prior to standard GLUT crosslinking could enhance tissue stability and thus heart valve durability.

  20. Vorticity dynamics of a bileaflet mechanical heart valve in an axisymmetric aorta

    Science.gov (United States)

    Dasi, L. P.; Ge, L.; Simon, H. A.; Sotiropoulos, F.; Yoganathan, A. P.

    2007-06-01

    We present comprehensive particle image velocimetry measurements and direct numerical simulation (DNS) of physiological, pulsatile flow through a clinical quality bileaflet mechanical heart valve mounted in an idealized axisymmetric aorta geometry with a sudden expansion modeling the aortic sinus region. Instantaneous and ensemble-averaged velocity measurements as well as the associated statistics of leaflet kinematics are reported and analyzed in tandem to elucidate the structure of the velocity and vorticity fields of the ensuing flow-structure interaction. The measurements reveal that during the first half of the acceleration phase, the flow is laminar and repeatable from cycle to cycle. The valve housing shear layer rolls up into the sinus and begins to extract vorticity of opposite sign from the sinus wall. A start-up vortical structure is shed from the leaflets and is advected downstream as the leaflet shear layers become wavy and oscillatory. In the second half of flow acceleration the leaflet shear layers become unstable and break down into two von Karman-like vortex streets. The onset of vortex shedding from the valve leaflets is responsible for the growth of significant cycle-to-cycle vorticity oscillations. At peak flow, the housing and leaflet shear layers undergo secondary instabilities and break down rapidly into a chaotic, turbulent-like state with multiple small-scale vortical structures emerging in the flow. During the deceleration and closing phases all large-scale coherent flow features disappear and a chaotic small-scale vorticity field emerges, which persists even after the valve has closed. Probability density functions of the leaflet position during opening and closing phases show that the leaflet position fluctuates from cycle to cycle with larger fluctuations evident during valve closure. The DNS is carried out by prescribing the leaflet kinematics from the experimental data. The computed instantaneous vorticity fields are in very good

  1. A Computational Tool for the Microstructure Optimization of a Polymeric Heart Valve Prosthesis.

    Science.gov (United States)

    Serrani, M; Brubert, J; Stasiak, J; De Gaetano, F; Zaffora, A; Costantino, M L; Moggridge, G D

    2016-06-01

    Styrene-based block copolymers are promising materials for the development of a polymeric heart valve prosthesis (PHV), and the mechanical properties of these polymers can be tuned via the manufacturing process, orienting the cylindrical domains to achieve material anisotropy. The aim of this work is the development of a computational tool for the optimization of the material microstructure in a new PHV intended for aortic valve replacement to enhance the mechanical performance of the device. An iterative procedure was implemented to orient the cylinders along the maximum principal stress direction of the leaflet. A numerical model of the leaflet was developed, and the polymer mechanical behavior was described by a hyperelastic anisotropic constitutive law. A custom routine was implemented to align the cylinders with the maximum principal stress direction in the leaflet for each iteration. The study was focused on valve closure, since during this phase the fibrous structure of the leaflets must bear the greatest load. The optimal microstructure obtained by our procedure is characterized by mainly circumferential orientation of the cylinders within the valve leaflet. An increase in the radial strain and a decrease in the circumferential strain due to the microstructure optimization were observed. Also, a decrease in the maximum value of the strain energy density was found in the case of optimized orientation; since the strain energy density is a widely used criterion to predict elastomer's lifetime, this result suggests a possible increase of the device durability if the polymer microstructure is optimized. The present method represents a valuable tool for the design of a new anisotropic PHV, allowing the investigation of different designs, materials, and loading conditions.

  2. Transcatheter mitral valve repair with mitraclip for significant mitral regurgitation long after heart transplantion.

    Science.gov (United States)

    Ferraro, Paolo; Biondi-Zoccai, Giuseppe; Giordano, Arturo

    2016-07-01

    The role of transcatheter mitral valve repair with MitraClip implantation is becoming increasingly important for high-risk surgical patients with significant mitral regurgitation. Eligibility criteria for MitraClip are however rather strict, and the risk-benefit balance of this device in off-label settings remains unclear. Patients with prior heart transplantation may represent particularly challenging candidates for MitraClip, given their peculiar atrial anatomy. We hereby present the case of a 72-year-old gentleman with prior heart transplantation and significant mitral regurgitation who, after heart team consensus, was referred to us for MitraClip implantation. After careful planning, we were able to successfully implant two clips, achieving a significant improvement in the severity of the mitral regurgitation. Similarly favorable findings were confirmed at 3-month clinical and transthoracic/transesophageal echocardiographic follow-up. This clinical vignette highlights the key procedural milestones for successfully implanting MitraClip in patients with significant mitral regurgitation and prior heart transplantation. © 2015 Wiley Periodicals, Inc. PMID:26333048

  3. Update to the study protocol, including statistical analysis plan for a randomized clinical trial comparing comprehensive cardiac rehabilitation after heart valve surgery with control

    DEFF Research Database (Denmark)

    Sibilitz, Kirstine Laerum; Berg, Selina Kikkenborg; Hansen, Tina Birgitte;

    2015-01-01

    BACKGROUND: Heart valve diseases are common with an estimated prevalence of 2.5% in the Western world. The number is rising because of an ageing population. Once symptomatic, heart valve diseases are potentially lethal, and heavily influence daily living and quality of life. Surgical treatment, e...

  4. Outlet strut fracture of Björk-Shiley convexo concave heart valves: the UK cohort study

    Science.gov (United States)

    Omar, R; Morton, L; Halliday, D; Danns, E; Beirne, M; Blot, W; Taylor, K

    2001-01-01

    OBJECTIVE—To investigate the risk of outlet strut fracture (OSF) in Björk-Shiley convexo concave (BSCC) valves in relation to patients' clinical and valve characteristics.
DESIGN—A cohort of 2977 patients with 3325 valves with a follow up of 18 years.
SETTING—38 cardiac implantation centres in the UK.
RESULTS—56 OSF events were reported with 43 occurring in mitral and 13 in aortic valves. The overall OSF rate was 0.17%/year. No dominant clinical factor of risk was found, but multiple regression analysis identified age, body surface area, valve size, shop order fracture rate, and manufacturing period as risk factors for OSF. A 4% (95% confidence interval (CI) 2% to 6%) decrease in the risk of OSF was observed for each advancing year of age and a fivefold (95% CI 2 to 13) increase in risk for a 0.5 m2 increase in body surface area. The association between the risk of OSF and valve size was not constant over time. Excess risks among 31 mm and 33 mm sizes (mainly mitral valves) decreased over time while that for 23 mm (almost all aortic valves) increased. The risk of OSF increased by 40% (95% CI 20% to 50%) for a unit increase in the fracture rate of other valves in the same batch. For valves manufactured during 1981 to 1984 the risk of OSF was 4 (95% CI 2 to 12) times greater than for valves manufactured before 1981.
CONCLUSIONS—The OSF rates for 60° BSCC valves observed in the UK are the highest among all monitored populations. The changing patterns of mitral and aortic valve OSF rates over time observed in this study have not been identified previously and highlight the need for continued monitoring of patients with the BSCC valve.


Keywords: cohort studies; heart valves; outlet strut fracture PMID:11410563

  5. Baseline MDCT findings after prosthetic heart valve implantation provide important complementary information to echocardiography for follow-up purposes

    Energy Technology Data Exchange (ETDEWEB)

    Sucha, Dominika; Mali, Willem P.T.M.; Habets, Jesse [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Chamuleau, Steven A.J. [University Medical Center Utrecht, Department of Cardiology, Utrecht (Netherlands); Symersky, Petr [VU Medical Center, Department of Cardiothoracic Surgery, Amsterdam (Netherlands); Meijs, Matthijs F.L. [Thoraxcentrum Twente, Medisch Spectrum Twente, Department of Cardiology, Enschede (Netherlands); Brink, Renee B.A. van den [Academic Medical Center, Department of Cardiology, Amsterdam (Netherlands); Mol, Bas A.J.M. de [Academic Medical Center, Department of Cardiothoracic Surgery, Amsterdam (Netherlands); Herwerden, Lex A. van [University Medical Center Utrecht, Department of Cardiothoracic Surgery, Utrecht (Netherlands); Budde, Ricardo P.J. [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Erasmus University Medical Center, Department of Radiology, Rotterdam (Netherlands)

    2016-04-15

    Recent studies have proposed additional multidetector-row CT (MDCT) for prosthetic heart valve (PHV) dysfunction. References to discriminate physiological from pathological conditions early after implantation are lacking. We present baseline MDCT findings of PHVs 6 weeks post implantation. Patients were prospectively enrolled and TTE was performed according to clinical guidelines. 256-MDCT images were systematically assessed for leaflet excursions, image quality, valve-related artefacts, and pathological and additional findings. Forty-six patients were included comprising 33 mechanical and 16 biological PHVs. Overall, MDCT image quality was good and relevant regions remained reliably assessable despite mild-moderate PHV-artefacts. MDCT detected three unexpected valve-related pathology cases: (1) prominent subprosthetic tissue, (2) pseudoaneurysm and (3) extensive pseudoaneurysms and valve dehiscence. The latter patient required valve surgery to be redone. TTE only showed trace periprosthetic regurgitation, and no abnormalities in the other cases. Additional findings were: tilted aortic PHV position (n = 3), pericardial haematoma (n = 3) and pericardial effusion (n = 3). Periaortic induration was present in 33/40 (83 %) aortic valve patients. MDCT allowed evaluation of relevant PHV regions in all valves, revealed baseline postsurgical findings and, despite normal TTE findings, detected three cases of unexpected, clinically relevant pathology. (orig.)

  6. Baseline MDCT findings after prosthetic heart valve implantation provide important complementary information to echocardiography for follow-up purposes

    International Nuclear Information System (INIS)

    Recent studies have proposed additional multidetector-row CT (MDCT) for prosthetic heart valve (PHV) dysfunction. References to discriminate physiological from pathological conditions early after implantation are lacking. We present baseline MDCT findings of PHVs 6 weeks post implantation. Patients were prospectively enrolled and TTE was performed according to clinical guidelines. 256-MDCT images were systematically assessed for leaflet excursions, image quality, valve-related artefacts, and pathological and additional findings. Forty-six patients were included comprising 33 mechanical and 16 biological PHVs. Overall, MDCT image quality was good and relevant regions remained reliably assessable despite mild-moderate PHV-artefacts. MDCT detected three unexpected valve-related pathology cases: (1) prominent subprosthetic tissue, (2) pseudoaneurysm and (3) extensive pseudoaneurysms and valve dehiscence. The latter patient required valve surgery to be redone. TTE only showed trace periprosthetic regurgitation, and no abnormalities in the other cases. Additional findings were: tilted aortic PHV position (n = 3), pericardial haematoma (n = 3) and pericardial effusion (n = 3). Periaortic induration was present in 33/40 (83 %) aortic valve patients. MDCT allowed evaluation of relevant PHV regions in all valves, revealed baseline postsurgical findings and, despite normal TTE findings, detected three cases of unexpected, clinically relevant pathology. (orig.)

  7. Heart valve surgery in China: past and present%中国心脏瓣膜外科的发展与现状

    Institute of Scientific and Technical Information of China (English)

    张宝仁

    2001-01-01

    @@ Heart valve surgery in China dates back to 4 to 5 decades ago. In 1954, the first closed mitral commissurotomy was successfully performed in a patient with mitral stenosis. In 1960, with the advent of transventricular dilator and by the route of left ventricle, the efficacy of mitral commissurotomy was improved. The procedure was rapidly adopted by many centers in this country[1]. In 1958, the first open heart surgery using cardiopulmonary bypass was performed in China. This was an epoch-making event, which opened up a new era in the field of cardiac surgery in China. Thereafter, in cities like Beijing and Shanghai, direct repairs of mitral lesions under CPB were made with good results. In 1965, the development of the first totally home-made ball valve prosthesis and its successful application in mitral valve replacement was another landmark in the history of heart valve surgery in China. In 1976, aortic valve replacement with glutaraldehyde-preserved bovine pericardial valve prosthesis was carried out successfully. The next year, the first porcine aortic valve prosthesis was produced and introduced to clinical use, which greatly accelerated the progress of heart valve surgery in China. During the last 2 decades, heart valve surgery and its techniques have been widely applied throughout China.

  8. Evaluation of bioprosthetic heart valve failure using a matrix-fibril shear stress transfer approach.

    Science.gov (United States)

    Anssari-Benam, Afshin; Barber, Asa H; Bucchi, Andrea

    2016-02-01

    A matrix-fibril shear stress transfer approach is devised and developed in this paper to analyse the primary biomechanical factors which initiate the structural degeneration of the bioprosthetic heart valves (BHVs). Using this approach, the critical length of the collagen fibrils l c and the interface shear acting on the fibrils in both BHV and natural aortic valve (AV) tissues under physiological loading conditions are calculated and presented. It is shown that the required critical fibril length to provide effective reinforcement to the natural AV and the BHV tissue is l c  = 25.36 µm and l c  = 66.81 µm, respectively. Furthermore, the magnitude of the required shear force acting on fibril interface to break a cross-linked fibril in the BHV tissue is shown to be 38 µN, while the required interfacial force to break the bonds between the fibril and the surrounding extracellular matrix is 31 µN. Direct correlations are underpinned between these values and the ultimate failure strength and the failure mode of the BHV tissue compared with the natural AV, and are verified against the existing experimental data. The analyses presented in this paper explain the role of fibril interface shear and critical length in regulating the biomechanics of the structural failure of the BHVs, for the first time. This insight facilitates further understanding into the underlying causes of the structural degeneration of the BHVs in vivo.

  9. Evaluation of bioprosthetic heart valve failure using a matrix-fibril shear stress transfer approach.

    Science.gov (United States)

    Anssari-Benam, Afshin; Barber, Asa H; Bucchi, Andrea

    2016-02-01

    A matrix-fibril shear stress transfer approach is devised and developed in this paper to analyse the primary biomechanical factors which initiate the structural degeneration of the bioprosthetic heart valves (BHVs). Using this approach, the critical length of the collagen fibrils l c and the interface shear acting on the fibrils in both BHV and natural aortic valve (AV) tissues under physiological loading conditions are calculated and presented. It is shown that the required critical fibril length to provide effective reinforcement to the natural AV and the BHV tissue is l c  = 25.36 µm and l c  = 66.81 µm, respectively. Furthermore, the magnitude of the required shear force acting on fibril interface to break a cross-linked fibril in the BHV tissue is shown to be 38 µN, while the required interfacial force to break the bonds between the fibril and the surrounding extracellular matrix is 31 µN. Direct correlations are underpinned between these values and the ultimate failure strength and the failure mode of the BHV tissue compared with the natural AV, and are verified against the existing experimental data. The analyses presented in this paper explain the role of fibril interface shear and critical length in regulating the biomechanics of the structural failure of the BHVs, for the first time. This insight facilitates further understanding into the underlying causes of the structural degeneration of the BHVs in vivo. PMID:26715134

  10. Univariate Risk Factors for Prolonged Mechanical Ventilation in Patients Undergoing Prosthetic Heart Valves Replacement Surgery

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Data from 736 patients undergoing prosthetic heart valve replacement surgery and concomitant surgery (combined surgery) from January 1998 to January 2004 at Union Hospital were retrospectively reviewed. Univariate logistic regression analyses were conducted to identify risk factors for prolonged mechanical ventilation. The results showed that prolonged cardiopulmonary bypass duration, prolonged aortic cross clamp time and low ejection fraction less than 50 percent (50 %)were found to be independent predictors for prolonged mechanical ventilation. Meanwhile age,weight, and preoperative hospital stay (days) were not found to be associated with prolonged mechanical ventilation. It was concluded that, for age and weight, this might be due to the lower number of old age patients (70 years and above) included in our study and genetic body structure of majority Chinese population that favor them to be in normal weight, respectively.

  11. Hemocompatibility research on the micro-structure surface of a bionic heart valve.

    Science.gov (United States)

    Ye, Xia; Wang, Ze; Zhang, Xianghua; Zhou, Ming; Cai, Lan

    2014-01-01

    In order to study how the geometric parameters and shape of the micro-structure surface of a bionic heart valve affects hemocompatibility, mastoid micro-structures with different periodic space were fabricated using a femtosecond laser on a polyurethane (PU) surface. The apparent contact angles of droplets on the micro-structure surfaces were measured to characterize their wettability. Then a series of blood compatibility experiments, including platelet adhesion, dynamic coagulation and hemolysis were completed. The experimental results showed that the micro-structure on the biomaterial surface helped improve its hydrophobicity and hemocompatibility. Also, the periodic space affected not only the hydrophobicity but also the hemocompatibility of the biomaterial. With the increasing of the periodic space, the apparent contact angle increased, the number of platelet adhesion decreased, the dynamic clotting time became longer and the hemolysis ratio reduced. In addition, the shape of the micro-structure also affected the hemocompatibility of the biomaterial.

  12. Minimally invasive thoracotomy approach for double valve replacement for valvular heart diseases

    Directory of Open Access Journals (Sweden)

    Ab Gani Ahangar

    2014-01-01

    Full Text Available Background: Double valve replacement (DVR is usually done through median sternotomy. However, right anterolateral thoracotomy is an alternative approach. Aim: The aim of this study was to analyze the results of right anterolateral thoracotomy for DVR. Patients and Methods: This was a prospective study conducted on during the period from January 2009 to January 2012. This study consists of 56 patients who had a concomitant mitral and aortic valve disease and were subjected to DVR. Patients were studied according to their age and sex, New York Heart Association (NYHA class, valve pathology, concomitant procedures, urgent/elective, length of incision, surgical exposure, mean bypass time, operating time, hospital stay, and cosmesis. Results: Majority of the patients were in 3 rd and 4 th decade (61%. Postoperative length of stay was 7-12 days, 70% of patients were discharged by the 7 th day. The average size of incision in males was 7.5 cm and in females the size of incision was 7.25 cm with a mean of 7.3 cm in both genders. Rheumatic heart disease was responsible for 89.28% of cardiac valvular lesions, degenerative disease in 7.14% and endocarditis in 3.5%. Postoperatively at 2 months, there was a statistically significant improvement in the NYHA class with 94% of the survivors in class I-II. There was a statistically significant difference in the outcome in patients having higher ejection fraction as compared to those who had low ejection fraction preoperatively. Thirty days mortality was 1.78%. Over the first 24 postoperative hours, only about 30% of patients were pain free, and this proportion increased to about 50% by day 2, 60% by day 3, 70% by day 4, 75% by day 5 and stabilized. Postoperative length of stay was 7-12 days, 70% of patients were discharged by the 7 th day. Conclusion: DVR via thoracotomy appears to be associated with faster recover, early discharge and reduced use of rehabilitation facilities that translate into a shorter

  13. Prospective ECG triggering reduces prosthetic heart valve-induced artefacts compared with retrospective ECG gating on 256-slice CT

    Energy Technology Data Exchange (ETDEWEB)

    Symersky, Petr [Academic Medical Center, Department of Cardiothoracic Surgery, Amsterdam (Netherlands); Habets, Jesse; Budde, Ricardo P.J. [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Westers, Paul [University Medical Center Utrecht, Department of Biostatistics, Julius Center for Health Sciences and Primary Care, Utrecht (Netherlands); Mol, Bas A.J.M. de [Academic Medical Center, Department of Cardiothoracic Surgery, Amsterdam (Netherlands); University of Technology Eindhoven, Department of Biomedical Engineering, Eindhoven (Netherlands); Prokop, Mathias [Radboud University Nijmegen Medical Center, Department of Radiology, Nijmegen (Netherlands)

    2012-06-15

    Multidetector computed tomography (MDCT) has diagnostic value for the evaluation of prosthetic heart valve (PHV) dysfunction but it is hampered by artefacts. We hypothesised that image acquisition using prospective triggering instead of retrospective gating would reduce artefacts related to pulsating PHV. In a pulsatile in vitro model, a mono- and bileaflet PHV were imaged using 256 MDCT at 60, 75 and 90 beats per minute (BPM) with either retrospective gating (120 kV, 600 mAs, pitch 0.2, CTDI{sub vol} 39.8 mGy) or prospective triggering (120 kV, 200 mAs, CTDI{sub vol} 13.3 mGy). Two thresholds (>175 and <-45HU), derived from the density of surrounding structures, were used for quantification of hyper- and hypodense artefacts. Image noise and artefacts were compared between protocols. Prospective triggering reduced hyperdense artefacts for both valves at every BPM (P = 0.001 all comparisons). Hypodense artefacts were reduced for the monoleaflet valve at 60 (P = 0.009), 75 (P = 0.016) and 90 BPM (P = 0.001), and for the bileaflet valves at 60 (P = 0.001), 90 (P = 0.001) but not at 75 BPM (P = 0.6). Prospective triggering reduced image noise at 60 (P = 0.001) and 75 (P < 0.03) but not at 90 BPM. Compared with retrospective gating, prospective triggering reduced most artefacts related to pulsating PHV in vitro. circle Computed tomographic images are often degraded by prosthetic heart valve-induced artefacts circle Prospective triggering reduces prosthetic heart valve-induced artefacts in vitro circle Artefact reduction at 90 beats per minute occurs without image noise reduction circle Prospective triggering may improve CT image quality of moving hyperdense structures. (orig.)

  14. Validation of four different risk stratification models in patients undergoing heart valve surgery in a single center in China

    Institute of Scientific and Technical Information of China (English)

    ZHANG Chun-xiao; XU Jian-ping; GE Yi-peng; WEI Yu; YANG Yan; LIU Feng; SHI Yi

    2011-01-01

    Background Several risk stratification models have been developed for cardiac surgery. This study aimed to evaluate the accuracy of four existing risk stratification models, the Fuwai System for Cardiac Operative Risk Evaluation (FuwaiSCORE), the Society of Thoracic Surgeons 2008 cardiac surgery risk model for isolated valve surgery (the STS model), the European System for Cardiac Operative Risk Evaluation (EuroSCORE) and the initial Parsonnet's score (the Parsonnet model) in predicting prolonged intensive care unit (ICU) stay in Chinese patients undergoing heart valve surgery. Methods Data were collected retrospectively from records of 1333 consecutive patients who received heart valve surgery in a single center between November 2006 and December 2007. Prolonged ICU stay was defined as not less than 124 hours. Calibration was assessed using the Hosmer-Lemeshow (H-L) goodness of fit test. Discrimination was assessed using the receiver-operating-characteristic (ROC) curve area. Results The FuwaiSCORE showed good calibration and discrimination compared with other risk models. According to the H-L statistics, the value of the FuwaiSCORE was 12.82, P>0.1. The area under ROC curve of the FuwaiSCORE was 0.81 (95%C/0.78-0.84). Conclusions Our study suggests that the FuwaiSCORE is superior to the other three risk models in predicting prolonged length of ICU stay in Chinese patients with heart valve surgery. Having fewer variables, the system is much easier for bedside use than other systems.

  15. Endocardial to myocardial notch-wnt-bmp axis regulates early heart valve development.

    Directory of Open Access Journals (Sweden)

    Yidong Wang

    Full Text Available Endocardial to mesenchymal transformation (EMT is a fundamental cellular process required for heart valve formation. Notch, Wnt and Bmp pathways are known to regulate this process. To further address how these pathways coordinate in the process, we specifically disrupted Notch1 or Jagged1 in the endocardium of mouse embryonic hearts and showed that Jagged1-Notch1 signaling in the endocardium is essential for EMT and early valvular cushion formation. qPCR and RNA in situ hybridization assays reveal that endocardial Jagged1-Notch1 signaling regulates Wnt4 expression in the atrioventricular canal (AVC endocardium and Bmp2 in the AVC myocardium. Whole embryo cultures treated with Wnt4 or Wnt inhibitory factor 1 (Wif1 show that Bmp2 expression in the AVC myocardium is dependent on Wnt activity; Wnt4 also reinstates Bmp2 expression in the AVC myocardium of endocardial Notch1 null embryos. Furthermore, while both Wnt4 and Bmp2 rescue the defective EMT resulting from Notch inhibition, Wnt4 requires Bmp for its action. These results demonstrate that Jagged1-Notch1 signaling in endocardial cells induces the expression of Wnt4, which subsequently acts as a paracrine factor to upregulate Bmp2 expression in the adjacent AVC myocardium to signal EMT.

  16. Role of thrombus precursor protein in assessment of anticoagulation in patients with atrial fibrillation after mechanical heart valve replacement

    Institute of Scientific and Technical Information of China (English)

    秦川; 肖颖彬; 陈林; 王学锋; 钟前进

    2004-01-01

    Objective: To explore the role of thrombus precursor protein (TpP) in assessment of anticoagulation and predict the risk of thromboembolism in the patients with atrial fibrillation (AF) after mechanical heart valve replacement. Methods: TpP plasma concentration and international normalization ratio (INR) were measured in 45 patients with atrial fibrillation and 45 patients with sinus rhythm both after mechanical heart valve replacement. Twenty patients with non-valvular heart diseases were selected as the control. Furthermore, the patients with AF were divided into groups based on different TpP plasma concentration and TpP plasma concentration and INR were analyzed. Results: After mechanical heart valve replacement, those with AF had higher TpP plasma concentration than those with sinus rhythm. It was found that discordancy existed between INR and TpP plasma concentration in the patients with AF. There were 28 AF patients with TpP plasma concentration lower than 6 μg/ml and without bleeding, who might be at the optimal anticoagulant state. The 95% confidence of the mean INR value was 1.90-2.30 in these patients and TpP plasma concentration was between 2.84-5.74 μg/ml. Conclusion: Patients with AF might face higher risk of thromboembolism after mechanical valve replacement; INR between 1.90-2.30 and TpP plasma concentration between 2.84-6 μg/ml might be the optimal anticoagulant range for patients with AF after mechanical valve replacement.

  17. Three-component laser Doppler velocimetry measurements in the vicinity of mechanical heart valves in a mock-circulatory loop

    Science.gov (United States)

    Meyer, Richard Scott

    Streakline flow visualization and three-component laser Doppler velocimetry were conducted in a mock-circulatory loop on four mechanical heart valve types in the mitral position. Measurements were conducted in the regurgitant flow region proximal to the valve. Results for the Bjork-Shiley Monostrutsp{TM} valve showed a highly non-uniform flow at valve closure, with very large velocities in the minor orifice region. These velocities were on the order of 15-20 mps and lasted less than one millisecond. Following closure, an interval of sustained regurgitant flow persisted for the duration of systole. Reynolds stresses were calculated from three-dimensional data, and yielded a maximum of 8,100 dyne/cmsp2. Values as high as 80,000 dyne/cmsp2 were calculated during the initial spike, but due to the intermittency of the spike, they are artificially high. Similar measurements were conducted in the minor orifice of the Medtronic-Hall valve, and maximum velocities of about 4 mps were measured during the sustained regurgitant flow. Maximum Reynolds shear stresses were about 7,000 dyne/cmsp2. The velocity spike at closing was noted with this valve also. Two-component measurements around the center hole in the occluder showed a sustained jet with maximum velocities of about 1 mps, and maximum Reynolds shear stresses of about 2,000 dyne/cmsp2. Measurements in the St. Jude Medical valve showed velocities and stresses to be very low. No closing spike was measured, and sustained velocities were observed in the hinge region of about 0.2 mps with maximum stresses of about 1,000 dyne/cmsp2. The CarboMedicssp{TM} valve showed a regurgitant jets emanating from the gap between the leaflet and valve housing ring, with velocities of 3.3 mps for the duration of systole, and calculated stresses of 8,100 dyne/cmsp2. No closing spike was noted. Differences between two and three-dimensional Reynolds shear stresses were significant only at locations where two-dimensional calculated values were

  18. The mediator complex subunit Med10 regulates heart valve formation in zebrafish by controlling Tbx2b-mediated Has2 expression and cardiac jelly formation.

    Science.gov (United States)

    Just, Steffen; Hirth, Sofia; Berger, Ina M; Fishman, Mark C; Rottbauer, Wolfgang

    2016-09-01

    In search for novel key regulators of cardiac valve formation, we isolated the zebrafish cardiac valve mutant ping pong (png). We find that an insertional promoter mutation within the zebrafish mediator complex subunit 10 (med10) gene is leading to impaired heart valve formation. Expression of the T-box transcription factor 2b (Tbx2b), known to be essential in cardiac valve development, is severely reduced in png mutant hearts. We demonstrate here that transient reconstitution of Tbx2b expression rescues AV canal development in png mutant zebrafish. By contrast, overexpression of Forkhead box N4 (Foxn4), a known upstream regulator of Tbx2b, is not capable to reconstitute tbx2b expression and heart valve formation in Med10-deficient png mutant hearts. Interestingly, hyaluronan synthase 2 (has2), a known downstream target of Tbx2 and producer of hyaluronan (HA) - a major ECM component of the cardiac jelly and critical for proper heart valve development - is completely absent in ping pong mutant hearts. We propose here a rather unique role of Med10 in orchestrating cardiac valve formation by mediating Foxn4 dependent tbx2b transcription, expression of Has2 and subsequently proper development of the cardiac jelly. PMID:27343557

  19. The Application of Bileaflet Mechanical Heart Valves in the Polish Ventricular Assist Device: Physical and Numerical Study and First Clinical Usage.

    Science.gov (United States)

    Malota, Zbigniew; Sadowski, Wojciech; Krzyskow, Marek; Stolarzewicz, Bogdan

    2016-03-01

    The Polish ventricular assist device (Polvad) has been used successfully in clinical contexts for many years. The device contains two single-disc valves, one at the inlet and one at the outlet connector of the pneumatic pump. Unfortunately, in recent years, a problem has occurred with the availability of single-disc valves. This article presents the possibility of using bileaflet mechanical heart valve prostheses in the Polvad to avoid a discontinuity in clinical use. The study is based on experimental and numerical simulations and comparison of the distribution of flow, pressure, and stress (wall, shear, and turbulent) inside the Polvad chamber and the inlet/outlet connectors fitted with Sorin Monodisc and Sorin Bicarbon Fitline valves. The type and orientation of the inlet valve affects valve performance and flow distribution inside the chamber. Near-wall flow is observed for single-disc valves. In the case of bileaflet valves, the main jet is directed more centrally, with lower shear stress but higher turbulent stress in comparison with single-disc valves. For clinical usage, a 45° orientation of the bileaflet inlet valve was chosen, as this achieves good washing of the inlet area near the membrane paste surface. The Polvad with bileaflet valves has now been used successfully in our clinic for over a year and will continue to be used until new assist devices for heart support are developed.

  20. Cavitation phenomena in mechanical heart valves: studied by using a physical impinging rod system.

    Science.gov (United States)

    Lo, Chi-Wen; Chen, Sheng-Fu; Li, Chi-Pei; Lu, Po-Chien

    2010-10-01

    When studying mechanical heart valve cavitation, a physical model allows direct flow field and pressure measurements that are difficult to perform with actual valves, as well as separate testing of water hammer and squeeze flow effects. Movable rods of 5 and 10 mm diameter impinged same-sized stationary rods to simulate squeeze flow. A 24 mm piston within a tube simulated water hammer. Adding a 5 mm stationary rod within the tube generated both effects simultaneously. Charged-coupled device (CCD) laser displacement sensors, strobe lighting technique, laser Doppler velocimetry (LDV), particle image velocimetry (PIV) and high fidelity piezoelectric pressure transducers measured impact velocities, cavitation images, squeeze flow velocities, vortices, and pressure changes at impact, respectively. The movable rods created cavitation at critical impact velocities of 1.6 and 1.2 m/s; squeeze flow velocities were 2.8 and 4.64 m/s. The isolated water hammer created cavitation at 1.3 m/s piston speed. The combined piston and stationary rod created cavitation at an impact speed of 0.9 m/s and squeeze flow of 3.2 m/s. These results show squeeze flow alone caused cavitation, notably at lower impact velocity as contact area increased. Water hammer alone also caused cavitation with faster displacement. Both effects together were additive. The pressure change at the vortex center was only 150 mmHg, which cannot generate the magnitude of pressure drop required for cavitation bubble formation. Cavitation occurred at 3-5 m/s squeeze flow, significantly different from the 14 m/s derived by Bernoulli's equation; the temporal acceleration of unsteady flow requires further study. PMID:20490686

  1. Hemodynamic Flow Characterization of St. Jude Medical Bileaflet Mechanical and Bioprosthetic Heart Valve Prostheses in a Left Ventricular Model via Digital Particle Image Velocimetry

    OpenAIRE

    Pierrakos, Olga

    2002-01-01

    The performance of the heart after a valve replacement operation will greatly depend on the flow character downstream the mitral valve thus a better understanding of the flow character is essential. Most in vitro studies of the flow downstream of a MHV have been conducted with the valve in the aortic position. Researchers reported detailed measurements most of which were obtained by Laser Doppler Velocimetry (LDV) in rigid models of the aorta. Digital Particle Image Velocimetry (DPIV) has a...

  2. Experience of valve replacement under mild hypothermia on pump-beating heart:an analysis of 800 cases

    Institute of Scientific and Technical Information of China (English)

    陈柏成; 肖颖彬; 陈林; 钟前进; 王学锋; 周骐; 易广兵

    2004-01-01

    Objective: To assess the outcome of valve replacement under mild hypothermia on pump-beating heart and to discuss the risk factors of cardiac valve surgery. Methods: In the period from November 1997 to May 2003, a total of 800cases of valve replacement were carried out in our institute. The clinical data were reviewed and the technique of mild hypothermia and pump-beating heart to replace cardiac valve was described in detail. Results: 800 patients, 308 male and 492female, with age range from 8 to 66 years, weighing 19 to 88 kg, underwent operation. The average cardiopulmonary bypass time was (109.38 ± 40.64) min, the average clamping time of the vena cava was (77.87 ± 27.99) min and the average mechanical ventilation time was (17.78 ± 12.21) h. There were 17 patients died in the early postoperative stage with an early mortality rate of 2.13%. The causes of death were failure in the weaning of extracorporeal circulation in 2 cases, severe low output syndrome in 3 cases, ventricular fibrillation in 3 cases, obstruction of coronary ostium of mechanical prosthetic valve in 1 case, hepatic failure in 2 cases, pulmonary failure in 1 case, multiorgan failure in 4 cases, and prosthetic valve dysfunction in 1 case. Severe postopertive complications occurred in 51 cases (6.375%), which included reexploration because of excessive bleeding in 16 cases (2.0%), lavage of poststemal infection in 2 cases (0.25%), postoperative strike in 7 cases (0.875%), pulmonary failure in 5 cases (0.625%), hepatic failure in 4 cases (0.5%), multiorgan failure in 11 cases (1.375 % ), ventricular arrhythmia in 5 cases (0.625%) and peripheral circulation failure in 1 case(0. 125 % ). Conclusion: Mild hypothermia and pump-beating heart result in satisfying clinical outcome in patients undergoing valve replacement. The integrated sequenced deairing procedure ensures the avoidance of air embolism during operation.Pump-beating heart technique offers a safe and practical option especially in

  3. Effect of Ligustrazine hydrochloride on coagulation reaction and inflammation reaction in single valve replacement patients with rheumatic heart disease undergoing cardiopulmonary bypass

    Institute of Scientific and Technical Information of China (English)

    陈益君

    2014-01-01

    Objective To observe the protection effect of Ligustrazine Hydrochloride(LH)on coagulation reaction and inflammation reaction in single valve replacement patients with rheumatic heart disease undergoing cardiopulmonary bypass(CPB).Methods Totally 40 patients undergoing single valve replacement were recruited in the study and randomly assigned to the two groups,the treatment group

  4. Transient pressure at closing of a monoleaflet mechanical heart valve prosthesis: mounting compliance effect.

    Science.gov (United States)

    Wu, Z J; Gao, B Z; Hwang, N H

    1995-09-01

    An in vitro experimental study was performed to investigate the mounting compliance effect on the occluder closing dynamics and the transient pressure at the closing of the mitral Medtronic Hall (MH) mechanical heart valve (MHV). The closing velocity and the transient pressure were simultaneously measured at heart rates of 70, 90, 120, and 140 beats/minute with cardiac outputs of 5.0, 6.0, 7.5, and 8.5 liters/minute, respectively. The experiment was conducted under simulated physiologic ventricular and aortic pressures in a pulsatile mock flow loop. The characteristics of the transient pressure were investigated by detailed mapping of the transient pressure field in the atrial chamber using high frequency pressure transducers. Simultaneous measurements of the occluder closing velocity and the transient pressure around the seat stop of the MH showed that the transient pressure generated on the inflow side dropped below the vapor pressure of liquid during the occluder's sudden deceleration at closing. The amplitude of the transient pressure reduction (TR) was proportional to the occluder approaching velocity. The development of the transient pressure in the rigid and flexible mountings were significantly different. In the rigid mounting (RM), the pressure was reduced below the liquid's vapor pressure and maintained below -350 mmHg for approximately 180 microseconds. Strong signals of high frequency pressure oscillations (HPO) were recorded in the transient pressure traces. The timing of the HPO was found to be consistent with that of the cavitation bubble collapse as observed by others. In the flexible mounting (FM), TR also occurred, but recovered quickly and was followed immediately by a positive pressure spike. Relatively weak HPO appeared in the transient pressure trace. The mapping of the transient pressure field showed that both the transient pressure reduction (on the major orifice side) or rise (on the minor orifice side) as well as the HPO were locally

  5. Mitral valve surgery in a patient with dextrocardia and 180° counter-clockwise rotated heart due to congenital agenesis of the right lung.

    Science.gov (United States)

    Atsumi, Yosuke; Tokunaga, Shigehiko; Yasuda, Shota; Fushimi, Kenichi; Masuda, Munetaka

    2013-11-01

    We report a case of severe mitral regurgitation (MR) with dextrocardia and 180° counterclockwise rotated situs solitus heart. We describe the technique for mitral valve surgery in a patient with dextrocardia and agenesis of the right lung.

  6. Successful use of danaparoid in two pregnant women with heart valve prosthesis and heparin-induced thrombocytopenia Type II (HIT).

    Science.gov (United States)

    Gerhardt, Andrea; Scharf, Rüdiger E; Zotz, Rainer B

    2009-01-01

    Anticoagulant therapy with heparin for the prevention of thromboembolism in pregnant women with prosthetic heart valves is associated with an increased risk to the mother and/or the fetus. A life-threatening complication of the therapy with heparin is heparin-induced thrombocytopenia type II (HIT). danaparoid has not yet been reported to be safe and effective for this indication. This study reports on a 26-year-old woman with tricuspidal valve prosthesis and a 37-year-old woman with a St. Jude Medical mitral valve prosthesis who were anticoagulated with danaparoid during pregnancy because of HIT. Anti-Xa levels were between 0.6 and 1.2 IU/mL during pregnancy with target levels of 1.0 IU/mL. Cesarean section was performed at anti-Xa levels of 0.3 and 0.7 IU/mL. One woman developed a placental hematoma at the 32nd week of gestation, which did not increase over the following week. Both patients delivered healthy boys. Heparin-induced thrombocytopenia in pregnant women with prosthetic heart valve can be successfully managed with danaparoid. PMID:18840630

  7. Neomycin and pentagalloyl glucose enhanced cross-linking for elastin and glycosaminoglycans preservation in bioprosthetic heart valves.

    Science.gov (United States)

    Tripi, Daniel R; Vyavahare, Naren R

    2014-01-01

    Glutaraldehyde cross-linked bioprosthetic heart valves fail within 12-15 years of implantation due to limited durability. Glutaraldehyde does not adequately stabilize extracellular matrix components such as glycosaminoglycans and elastin, and loss of these components could be a major cause of degeneration of valve after implantation. We have shown earlier that neomycin-based cross-linking stabilizes glycosaminoglycans in the tissue but fails to stabilize elastin component. Here, we report a new treatment where neomycin and pentagalloyl glucose (PGG) were incorporated into glutaraldehyde cross-linking neomycin-PGG-Glutaraldehyde (NPG) to stabilize both glycosaminoglycans and elastin in porcine aortic valves. In vitro studies demonstrated a marked increase in extracellular matrix stability against enzymatic degradation after cross-linking and 10 month storage in NPG group when compared to glutaraldehyde controls. Tensile properties showed increased lower elastic modulus in both radial and circumferential directions in NPG group as compared to glutaraldehyde, probably due to increased elastin stabilization with no changes in upper elastic modulus and extensibility. The enhanced extracellular matrix stability was further maintained in NPG-treated tissues after rat subdermal implantation for three weeks. NPG group also showed reduced calcification when compared to glutaraldehyde controls. We conclude that NPG cross-linking would be an excellent alternative to glutaraldehyde cross-linking of bioprosthetic heart valves to improve its durability.

  8. Heart transplantation as salvage therapy for progressive prosthetic valve endocarditis due to methicillin-resistant Staphylococcus epidermidis (MRSE)

    OpenAIRE

    Borde, J. P.; Sitaru, G.; Kopp, W. H.; Ruhparwar, A.; Ehlermann, P.; Lasitschka, F.; Dalpke, A.; Heininger, A

    2016-01-01

    Background Prosthetic valve endocarditis (PVE) has the highest in-hospital mortality among all cases of infective endocarditis (IE), it is estimated at about 40 %. Orthotopic heart transplantation (OHT) as a measure of last resort, may be considered in selected cases where repeated surgical procedures and conservative efforts have failed to eradicate persistent or recurrent IE. Only few clinical data are available regarding this rare indication for OHT, since active IE has traditionally been ...

  9. A novel iterative reconstruction algorithm allows reduced dose multidetector-row CT imaging of mechanical prosthetic heart valves

    OpenAIRE

    Habets, Jesse; Symersky, Petr; de Mol, Bas A. J. M.; Willem P Th M Mali; Leiner, Tim; Budde, Ricardo P.J.

    2011-01-01

    Multidetector-row CT is promising for prosthetic heart valve (PHV) assessment but retrospectively ECG-gated scanning has a considerable radiation dose. Recently introduced iterative reconstruction (IR) algorithms may enable radiation dose reduction with retained image quality. Furthermore, PHV image quality on the CT scan mainly depends on extent of PHV artifacts. IR may decrease streak artifacts. We compared image noise and artifact volumes in scans of mechanical PHVs reconstructed with conv...

  10. Auscultatory characteristics of normally functioning Lillehei-Kaster, Björk-Shiley, and St Jude heart valve prostheses.

    OpenAIRE

    Kupari, M.; Harjula, A; Mattila, S

    1986-01-01

    Auscultatory and echocardiographic and phonocardiographic studies were performed on 26 patients who had a total of 11 Lillehei-Kaster, 16 Björk-Shiley, and 18 St Jude heart valve prostheses functioning normally in the aortic or mitral positions or both. With all types and positions of prostheses a distinct closing sound was always detected. It was frequently heard in two parts which, according to echocardiographic and phonocardiographic studies, resulted from the onset and completion of the v...

  11. Valve-in-valve implantation with a 23-mm balloon-expandable transcatheter heart valve for the treatment of a 19-mm stentless bioprosthesis severe aortic regurgitation using a strategy of "extreme" underfilling.

    Science.gov (United States)

    Chevalier, Florent; Leipsic, Jonathon; Généreux, Philippe

    2014-09-01

    We report a case of valve-in-valve (ViV) implantation by transfemoral approach with a 23-mm balloon-expandable prosthesis inside a stentless 19-mm acutely degenerated bioprosthesis, using a strategy of "extreme" underfilling. A 74-year-old patient presented to our institution in cardiogenic shock. An initial transesophageal echocardiography (TEE) showed severe central aortic regurgitation (AR) due to a torn leaflet. She was deemed inoperable and considered for urgent transcatheter aortic valve replacement. Given the fairly small true internal diameter, a strategy of 3-cc underfilling of a 23-mm transcatheter heart valve (THV) was planned. However, the final implantation was performed with 5-cc underfilling due to the incapacity to deliver the entire amount of fluid contained in the inflation syringe. TEE guidance confirmed the successful positioning and deployment of the prosthesis, with no AR and a mean gradient of 25 mm Hg. While implantation of a smaller prosthesis (20 mm) was debated during the Heart Team discussion, the risk of valve embolization due to inadequate anchoring inside the stentless prosthesis led to the selection of a 23-mm THV. At 6-month follow-up, the patient was in NYHA class I, with no AR and a mean gradient of 28 mm Hg. We report for the first time the use of in vivo THV with 5-cc underfilling with no acute or short-term structural failure, and the first ViV implantation by transfemoral approach with a 23-mm balloon-expandable prosthesis inside a stentless 19-mm bioprosthesis. The current report presents the challenges related to ViV implantation inside a small stentless bioprosthesis and offers practical ways to overcome them. © 2014 Wiley Periodicals, Inc.

  12. Functional Heart Valve Scaffolds Obtained by Complete Decellularization of Porcine Aortic Roots in a Novel Differential Pressure Gradient Perfusion System.

    Science.gov (United States)

    Sierad, Leslie Neil; Shaw, Eliza Laine; Bina, Alexander; Brazile, Bryn; Rierson, Nicholas; Patnaik, Sourav S; Kennamer, Allison; Odum, Rebekah; Cotoi, Ovidiu; Terezia, Preda; Branzaniuc, Klara; Smallwood, Harrison; Deac, Radu; Egyed, Imre; Pavai, Zoltan; Szanto, Annamaria; Harceaga, Lucian; Suciu, Horatiu; Raicea, Victor; Olah, Peter; Simionescu, Agneta; Liao, Jun; Movileanu, Ionela; Harpa, Marius; Simionescu, Dan Teodor

    2015-12-01

    There is a great need for living valve replacements for patients of all ages. Such constructs could be built by tissue engineering, with perspective of the unique structure and biology of the aortic root. The aortic valve root is composed of several different tissues, and careful structural and functional consideration has to be given to each segment and component. Previous work has shown that immersion techniques are inadequate for whole-root decellularization, with the aortic wall segment being particularly resistant to decellularization. The aim of this study was to develop a differential pressure gradient perfusion system capable of being rigorous enough to decellularize the aortic root wall while gentle enough to preserve the integrity of the cusps. Fresh porcine aortic roots have been subjected to various regimens of perfusion decellularization using detergents and enzymes and results compared to immersion decellularized roots. Success criteria for evaluation of each root segment (cusp, muscle, sinus, wall) for decellularization completeness, tissue integrity, and valve functionality were defined using complementary methods of cell analysis (histology with nuclear and matrix stains and DNA analysis), biomechanics (biaxial and bending tests), and physiologic heart valve bioreactor testing (with advanced image analysis of open-close cycles and geometric orifice area measurement). Fully acellular porcine roots treated with the optimized method exhibited preserved macroscopic structures and microscopic matrix components, which translated into conserved anisotropic mechanical properties, including bending and excellent valve functionality when tested in aortic flow and pressure conditions. This study highlighted the importance of (1) adapting decellularization methods to specific target tissues, (2) combining several methods of cell analysis compared to relying solely on histology, (3) developing relevant valve-specific mechanical tests, and (4) in vitro testing

  13. Computational simulations of flow dynamics and blood damage through a bileaflet mechanical heart valve scaled to pediatric size and flow.

    Science.gov (United States)

    Yun, B Min; McElhinney, Doff B; Arjunon, Shiva; Mirabella, Lucia; Aidun, Cyrus K; Yoganathan, Ajit P

    2014-09-22

    Despite pressing needs, there are currently no FDA approved prosthetic valves available for use in the pediatric population. This study is performed for predictive assessment of blood damage in bileaflet mechanical heart valves (BMHVs) with pediatric sizing and flow conditions. A model of an adult-sized 23 mm St. Jude Medical (SJM) Regent(™) valve is selected for use in simulations, which is scaled in size for a 5-year old child and 6-month old infant. A previously validated lattice-Boltzmann method (LBM) is used to simulate pulsatile flow with thousands of suspended platelets for cases of adult, child, and infant BMHV flows. Adult BMHV flows demonstrate more disorganized small-scale flow features, but pediatric flows are associated with higher fluid shear stresses. Platelet damage in the pediatric cases is higher than in adult flow, highlighting thrombus complication dangers of pediatric BMHV flows. This does not necessarily suggest clinically important differences in thromboembolic potential. Highly damaged platelets in pediatric flows are primarily found far downstream of the valve, as there is less flow recirculation in pediatric flows. In addition, damage levels are well below expected thresholds for platelet activation. The extent of differences here documented between the pediatric and adult cases is of concern, demanding particular attention when pediatric valves are designed and manufactured. However, the differences between the pediatric and adult cases are not such that development of pediatric sized valves is untenable. This study may push for eventual approval of prosthetic valves resized for the pediatric population. Further studies will be necessary to determine the validity and potential thrombotic and clinical implications of these findings. PMID:25011622

  14. Arteriosclerotic changes in the myocardium, lung, and kidney in dogs with chronic congestive heart failure and myxomatous mitral valve disease

    DEFF Research Database (Denmark)

    Falk, Bo Torkel; Jönsson, Lennart; Olsen, Lisbeth Høier;

    2006-01-01

    Background: The occurrence of small vessel arteriosclerosis in the myocardium, kidney, and lung in dogs with naturally occurring myxomatous mitral valve disease has not been previously investigated systematically. Methods: Twenty-one dogs with naturally occurring congestive heart failure and 21 age......-matched, sex-matched, and weight-matched control dogs underwent extensive pathological and histopathological examination. Morphometry and scoring of tissue sections were used to measure arterial narrowing and fibrosis in the myocardium, kidney, and lung; and intimal thickness and plaque formation in the aorta...... and pulmonary artery. Results: Dogs with congestive heart failure had significantly more arterial narrowing in the left ventricle (Pdogs. However...

  15. Heart murmurs

    Science.gov (United States)

    Chest sounds - murmurs; Heart sounds - abnormal; Murmur - innocent; Innocent murmur; Systolic heart murmur; Diastolic heart murmur ... The heart has 4 chambers: Two upper chambers (atria) Two lower chambers (ventricles) The heart has valves that close ...

  16. Novel imaging strategies for the detection of prosthetic heart valve obstruction and endocarditis.

    Science.gov (United States)

    Tanis, W; Budde, R P J; van der Bilt, I A C; Delemarre, B; Hoohenkerk, G; van Rooden, J-K; Scholtens, A M; Habets, J; Chamuleau, S

    2016-02-01

    Prosthetic heart valve (PHV) dysfunction remains difficult to recognise correctly by two-dimensional (2D) transthoracic and transoesophageal echocardiography (TTE/TEE). ECG-triggered multidetector-row computed tomography (MDCT), 18-fluorine-fluorodesoxyglucose positron emission tomography including low-dose CT (FDG-PET) and three-dimensional transoesophageal echocardiography (3D-TEE) may have additional value. This paper reviews the role of these novel imaging tools in the field of PHV obstruction and endocarditis.For acquired PHV obstruction, MDCT is of additional value in mechanical PHVs to differentiate pannus from thrombus as well as to dynamically study leaflet motion and opening/closing angles. For biological PHV obstruction, additional imaging is not beneficial as it does not change patient management. When performed on top of 2D-TTE/TEE, MDCT has additional value for the detection of both vegetations and pseudoaneurysms/abscesses in PHV endocarditis. FDG-PET has no complementary value for the detection of vegetations; however, it appears more sensitive in the early detection of pseudoaneurysms/abscesses. Furthermore, FDG-PET enables the detection of metastatic and primary extra-cardiac infections. Evidence for the additional value of 3D-TEE is scarce.As clinical implications are major, clinicians should have a low threshold to perform additional MDCT in acquired mechanical PHV obstruction. For suspected PHV endocarditis, both FDG-PET and MDCT have complementary value. PMID:26744343

  17. Hemostatic Markers in Congestive Heart Failure Dogs with Mitral Valve Disease

    Directory of Open Access Journals (Sweden)

    Kreangsak Prihirunkit

    2014-01-01

    Full Text Available Prothrombin time (PT, activated partial thromboplastin time (APTT, fibrinogen, D-dimer, antithrombin III (AT III, protein C (PC, factor VII (F.VII, and factor VIII (F.VIII, as well as hematocrit (HCT, platelets number (PLT, total plasma protein (TP, and albumin (ALB, were studied on fifty-eight congestive heart failure (CHF dogs with mitral valve disease (MVD and fifty control dogs. All of variables of MVD group, except APTT, were significantly different (P<0.5 from control group. The variables were also compared among functional classes of CHF dogs and control dogs. It was determined that the higher the functional class of CHF dogs was, the greater the levels of fibrinogen and D-dimer were, whereas the lesser the activities of AT III and PC were presented. Additionally, TP had linear correlation with fibrinogen, D-dimer, HCT, and PLT (r=0.31, 0.30, 0.43, and 0.38, resp., P<0.5. These findings suggested that fibrinogen and D-dimer were the factors predisposing hypercoagulability through an increase in blood viscosity. The hemorheological abnormalities would shift an overall hemostatic balance toward a more thrombotic state in CHF dogs with MVD.

  18. Prevalence of De Novo Aortic Valve Insufficiency in Patients After HeartWare VAD Implantation with an Intermittent Low-Speed Algorithm.

    Science.gov (United States)

    Saeed, Diyar; Westenfeld, Ralf; Maxhera, Bujar; Keymel, Stefanie; Sherif, Ahmed; Sadat, Najla; Petrov, GeorGI; Albert, Alexander; Lichtenberg, Artur

    2016-01-01

    De novo aortic valve insufficiency (AI) is a frequent occurrence in patients supported with left ventricular assist device (LVAD). The European version of the HeartWare LVAD has intermittent low-speed software (lavare cycle) to facilitate intermittent aortic valve opening. We examined aortic valve opening status and prevalence of AI in patients supported with HeartWare LVAD and activated lavare cycle. HeartWare LVAD patients were prospectively monitored using serial echocardiograms at different time points after the LVAD implantation. Inclusion criteria were patients with no > mild AI and/or no aortic valve surgery at the time of LVAD implantation and at least 60 days of support. Three of 37 patients had aortic valve surgery and were excluded from the analysis. A total of 34 patients with mean age of 57 ± 12 years met the inclusion criteria. After median support duration of 408 days (77-1250 days), eight patients had trace/mild AI (24%) and one patient developed moderate AI (3%). An average pump flow, speed, and mean arterial pressure of 4.4 ± 0.6 L/min, 2,585 ± 147 rpm, and 88 ± 11 mmHg were documented, respectively. Aortic valve opening was persistently seen in 22 patients (65%). Aortic valve opening is frequent, and the development of > mild AI seems to be rare in patients supported with HeartWare LVAD. PMID:27195744

  19. Postoperative Migration of an Edwards-SAPIEN XT Mitral Valve-in-Valve Treated With Direct Vision Implantation During Beating-Heart Bypass.

    Science.gov (United States)

    Mick, Stephanie L; Roselli, Eric E; Kapadia, Samir; Tuzcu, E Murat; Krishnaswamy, Amar; Svensson, Lars G

    2016-03-01

    Transcatheter valve-in-valve mitral valve replacement provides treatment options to high-risk patients but is subject to its own complications. We present the migration of a transcatheter balloon-expandable Edwards-SAPIEN XT valve (Edwards Lifesciences, Irvine, CA) within a previously implanted surgical Carpentier-Edwards valve (Edwards Lifesciences) and our novel approach to its treatment. PMID:26897205

  20. Development of an Animal Experimental Model for a Bileaflet Mechanical Heart Valve Prosthesis

    OpenAIRE

    Choo, Suk Jung; Kim, Kun Il; Park, Nam Hee; Song, Jong Min; Choi, In Cheol; Shim, Jee Yeon; Lee, Sang Kwon; Kwon, Young Joo; Kim, Chang Nyung; Lee, Jae Won

    2004-01-01

    The objective of this study was to develop a pre-clinical large animal model for the in vivo hemodynamic testing of prosthetic valves in the aortic position without the need for cardiopulmonary bypass. Ten male pigs were used. A composite valved conduit was constructed in the operating room by implanting a prosthetic valve between two separate pieces of vascular conduits, which bypassed the ascending aorta to the descending aorta. Prior to applying a side-biting clamp to the ascending aorta f...

  1. sup 99m Tc-labelled anti NCA-95 antibodies in prosthetic heart valve endocarditis

    Energy Technology Data Exchange (ETDEWEB)

    Bair, H.J.; Becker, W.; Wolf, F. (Dept. of Nuclear Medicine, Univ. Erlangen-Nuernberg, Erlangen (Germany)); Volkholz, H.J. (Dept. of Internal Medicine 1, Univ. of Erlangen-Nuernberg, Erlangen (Germany))

    1991-08-01

    A 54-y old women with earlier replacement of the mitral and aortic valves and clinical signs of localized endocarditis was studied with {sup 99m}Tc-labelled anti NCA-95 antibody. Whereas echocardiographic findings were negative, increased radionuclide uptake was observed left parasternal over the mitral valve as a sign of prosthetic valve endocarditis. This result could be confirmed by a similar study with leukocytes labelled in vitro with {sup 111}In-oxine. (orig.).

  2. A NUMERICAL ANALYSIS OF THE BLOOD FLOW AROUND THE BILEAFLET MECHANICAL HEART VALVES WITH DIFFERENT ROTATIONAL IMPLANTATION ANGLES

    Institute of Scientific and Technical Information of China (English)

    HONG Taehyup; KIM Chang Nyung

    2011-01-01

    The effects of implantation angles of Bileaflet Mechanical Heart Valves (BMHVs) on the blood flow and the leaflet motion are investigated in this paper.The physiological blood flow interacting with the moving leaflets ofa BMHV is simulated with a strongly coupled implicit Fluid-Structure Interaction (FSI) method based on the Arbitrary-Lagrangian-Eulerian (ALE) approach and the dynamic mesh method (remeshing) in Fluent.BMHVs are widely used to be implanted to replace the diseascd heart valves,but the patients would suffer from some complications such as hemolysis,platelet activation,tissue overgrowth and device failure.These complications are closely related to both the flow characteristics near the valves and the leaflet dynamics.The currentnumerical model is validated against a previous experimental study.The numerical results show that as the rotation angle of BMHV is increased the degree of asymmetry of the blood flow and the leaflet motion is increased,which may lead to an unbalanced force acting on the BMHVs.This study shows the applicability of the FSI model for the interaction between the blood flow and the leaflet motion in BMHVs.

  3. CFD simulation of a novel bileaflet mechanical heart valve prosthesis: an estimation of the Venturi passage formed by the leaflets.

    Science.gov (United States)

    Yokoyama, Y; Medart, D; Hormes, M; Schmitz, C; Hamilton, K; Kwant, P B; Takatani, S; Schmitz-Rode, T; Steinseifer, U

    2006-12-01

    The aim of this study was to validate the flow characteristics of the novel Helmholtz-Institute Aachen Bileaflet (HIA-BL) heart valve prosthesis. The curved leaflets of the HIA-BL valve form a Venturi passage between the leaflets at peak systole. By narrowing the cross section the flow accelerates and the static pressure at the central passage decreases according to the Venturi effect. The low-pressure zone between the leaflets is expected to stabilize the leaflets in fully open position at peak systole. To investigate the Venturi passage, the flow fields of two valve geometries were investigated by CFD (Computational Fluid Dynamics): one geometry exhibits curved leaflets resulting in a Venturi passage; the other geometry features straight leaflets. The flow profiles, pressure distribution and resulting torque of both passages were compared and investigated. Although flow profiles downstream of both valves were similar, the flow passages between the leaflets were different for the investigated leaflet geometries. The straight leaflet passage showed a large boundary layer separation zone near the leaflets and the lowest pressure at the leading edge of the leaflet. The Venturi passage showed a reduction of the boundary layer separation zones and the lowest pressure between the leaflets could be found in the narrowest flow cross section of the Venturi passage. Additionally, the resulting torque showed that the Venturi passage produced an opening momentum. The results demonstrate that the Venturi passage stabilizes the leaflets in open position at peak systole. PMID:17219353

  4. Collagen tissue treated with chitosan solutions in carbonic acid for improved biological prosthetic heart valves.

    Science.gov (United States)

    Gallyamov, Marat O; Chaschin, Ivan S; Khokhlova, Marina A; Grigorev, Timofey E; Bakuleva, Natalia P; Lyutova, Irina G; Kondratenko, Janna E; Badun, Gennadii A; Chernysheva, Maria G; Khokhlov, Alexei R

    2014-04-01

    Calcification of bovine pericardium dramatically shortens typical lifetimes of biological prosthetic heart valves and thus precludes their choice for younger patients. The aim of the present work is to demonstrate that the calcification is to be mitigated by means of treatment of bovine pericardium in solutions of chitosan in carbonic acid, i.e. water saturated with carbon dioxide at high pressure. This acidic aqueous fluid unusually combines antimicrobial properties with absolute biocompatibility as far as at normal pressure it decomposes spontaneously and completely into H2O and CO2. Yet, at high pressures it can protonate and dissolve chitosan materials with different degrees of acetylation (in the range of 16-33%, at least) without any further pretreatment. Even exposure of the bovine pericardium in pure carbonic acid solution without chitosan already favours certain reduction in calcification, somewhat improved mechanical properties, complete biocompatibility and evident antimicrobial activity of the treated collagen tissue. The reason may be due to high extraction ability of this peculiar compressed fluidic mixture. Moreover, exposure of the bovine pericardium in solutions of chitosan in carbonic acid introduces even better mechanical properties and highly pronounced antimicrobial activity of the modified collagen tissue against adherence and biofilm formation of relevant Gram-positive and Gram-negative strains. Yet, the most important achievement is the detected dramatic reduction in calcification for such modified collagen tissues in spite of the fact that the amount of the thus introduced chitosan is rather small (typically ca. 1wt.%), which has been reliably detected using original tritium labelling method. We believe that these improved properties are achieved due to particularly deep and uniform impregnation of the collagen matrix with chitosan from its pressurised solutions in carbonic acid. PMID:24582232

  5. Anticoagulation in pregnant women with mechanical heart valves : the new ESC guidelines

    NARCIS (Netherlands)

    Pieper, P. G.

    2012-01-01

    In pregnant women with a mechanical valve prosthesis, anticoagulation therapy is challenging because of the risk of embryopathy with vitamin K antagonists (VKA's), while unfractioned heparin and low molecular weight heparin (LMWH) are associated with a higher risk of valve thrombosis [1]. The presen

  6. 国产人工机械瓣膜的历史与研究进展%History and Research Advance of China-made Mechanical Heart Valves

    Institute of Scientific and Technical Information of China (English)

    祁亮

    2013-01-01

    人工心脏瓣膜的应用至今已有50多年的历史,其中机械瓣膜在瓣膜病治疗中有着显著的临床疗效.回顾人工机械瓣膜的研究历史,大至经历了从第一代笼球瓣、笼碟瓣到第二代单叶侧倾碟瓣,再到第三代双叶机械瓣的发展过程.1960年国外首次应用笼球式机械瓣行心瓣膜置换术,我国在1963年也研制出了国产笼球瓣并应用于临床;1969年国外研制出第二代单叶侧倾碟瓣,国内于1978年研制出国产单叶侧倾碟瓣并广泛应用,取得了良好的临床疗效.从1980年双叶机械瓣问世至今,双叶瓣以优异的性能淘汰了以上两种瓣膜,成为当今的主流产品,而目前国内对双叶瓣的研发相对滞后,国内人工心脏瓣膜的市场也几乎被国外双叶瓣所垄断.因此,理想的人工心脏瓣膜有待国人继续研究开发.%Clinical application history of prosthetic heart valves has been over five decades, and mechanical heart valves have satisfactory clinical outcomes for surgical treatment of valvular heart disease. The development history of mechanical heart valves experienced from the first generation of ball valves and caged disc valves to the second generation of single tilting disc valve, and to the third generation of bileaflet valves. In 1960, ball valve was first used for heart valve replacement in abroad. In 1963, China-made ball valve was also produced and used in clinical practice. In 1969, the second generation of single tilting disc valve was developed in abroad. In 1978, China-made single tilting disc valve was produced and widely used in clinical practice with satisfactory clinical outcomes. Since 1980 when it was first produced, bileaflet valve has taken the place of above 2 types of valves for its excellent performance, and become the mainstream product all over the world. Currently, the development of China-made bileaflet valves has lagged behind, and domestic mechanical heart valve market has almost been

  7. Heart rate variability parameters of myxomatous mitral valve disease in dogs with and without heart failure obtained using 24-hour Holter electrocardiography.

    Science.gov (United States)

    Oliveira, M S; Muzzi, R A L; Araújo, R B; Muzzi, L A L; Ferreira, D F; Nogueira, R; Silva, E F

    2012-06-16

    Time-domain heart rate variability (HRV) parameters and the correlation between echocardiography and Holter examinations in dogs with myxomatous mitral valve disease (MMVD) were determined. Holter examination was also performed at different time frames: an entire 24-hour period, a four-hour period during sleep, and a four-hour period while awake. Ten healthy (control group) and 28 MMVD dogs, 15 with and 13 without heart failure, were evaluated. The SDANN (sd of the mean normal RR intervals for all five-minute segments during 24-hour Holter) and pNN(50) (percentage of differences between adjacent normal RR intervals that are >50 ms computed over 24-hour Holter) variables were significantly lower in the dogs with MMVD heart failure. The differences in HRV between the groups were only detected during the 24-hour evaluation period (PHolter and echocardiography examinations when considering pNN(50), SDANN, and LA/AO (left atrial to aortic root ratio) (r=0.92; P<0.05), indicating that both are important in evaluating MMVD dogs. SDANN and pNN(50) are measures of parasympathetic control of the heart, and thus, it is possible to infer that the MMVD dogs exhibit parasympathetic withdrawal during the development of heart failure.

  8. Ekhokardiografi Endokardiosis Penyakit Katup Mitral Jantung Anjing (ECHOCARDIOGRAPHY OF ENDOCARDIOSIS MITRAL VALVE HEART DISEASE IN DOGS

    Directory of Open Access Journals (Sweden)

    Deni Noviana

    2013-08-01

    Full Text Available Endocardiosis is a disease commonly found in Pomeranian dog characterized by progressive myxomatousdegeneration of the atrio-ventricular valves especially in the mitral valve. The purpose of this study was todefine the diagnose and severeity of this disease on the Pomeranian by using brightness mode, motion mode,dan color flow Doppler echocardiography technique. Echocardiography was performed on 8 Pomeranianconsisting of 6 males and 2 females with age range of 2-14 years. Brightness mode echocardiography wasused to see the echotexture of endocardium, mitral valve, and the valve movement. The results showedendocardium thickening, along with chronic fibrosis and nodular thickening of the anterior and posteriormitral valve leaflet. Three out of seven cases showed prolapsed of the mitral valve. Motion modeechocardiography was performed in order to measure left ventricle internal dimension, myocardium thickness,fractional shortening, left atrial and aortic dimension. The results showed myocardium thickening, alongwith left atrial enlargement. Color flow Doppler echocardiography was used to confirm the mitral valveregurgitation. Three of seven cases showed the presence of regurgitation signed by turbulence color of theprolapsed mitral valve. Based on the degree of severity, scoring system used in this study, endocardiosis canbe divided into three types that are mild, moderate and severe.

  9. Is the European System for Cardiac Operative Risk Evaluation useful in Chinese patients undergoing heart valve surgery?

    Institute of Scientific and Technical Information of China (English)

    ZHENG Shuai; ZHENG Zhe; FAN Hong-guang; HU Sheng-shou

    2012-01-01

    Background The European System for Cardiac Operative Risk Evaluation (EuroSCORE) is one of the most widely used risk models for the predicting mortality after cardiac surgery.The aim of this study was to validate the EuroSCORE model for predicting operative mortality in heart valve surgery on a Chinese multicenter database and comparing the performance of EuroSCORE with our new risk stratification system,the Sino System for Coronary Operative Risk Evaluation (SinoSCORE).Methods Data from patients undergoing heart valve surgery between January 2007 and December 2008 were retrospectively collected,from 43 hospitals in China.The EuroSCORE and the SinoSCORE were calculated for each patient.Mortality was defined as any in-hospital death.Area under the receiver operating characteristics curve (AUG)was used to study the discriminatory abilities of the models.The Hosmer-Lemeshow (H-L) goodness-of-fit test was used to study the calibration of the predictive models.Results A total of 15 367 patients were analyzed.For the entire cohort,the observed mortality was 2.34%,the predicted mortality was 3.71% (additive),3.19% (logistic) and 3.66% (SinoSCORE).AUC was 0.747 for SinoSCORE,0.699 additive and 0.696 for logistic EuroSCORE.Calibration of SinoSCORE and additive EuroSCORE was good (H-L:P=0.250 and P=0.051,respectively),but the logistic EuroSCORE model had a poor calibration (H-L:P<0.05).The discriminatory ability and calibration of the SinoSCORE were good in low- and high-risk patients.However,the discriminatory ability of the EuroSCORE model was poor in all risk deciles.Conclusions The EuroSCORE does not accurately predict mortality in Chinese patients with heart valve surgery,and the SinoSCORE is superior to the EuroSCORE at predicting in-hospital mortality in Chinese heart valve surgery patients.

  10. Collagen tissue treated with chitosan solutions in carbonic acid for improved biological prosthetic heart valves

    Energy Technology Data Exchange (ETDEWEB)

    Gallyamov, Marat O., E-mail: glm@spm.phys.msu.ru [Faculty of Physics, Lomonosov Moscow State University, Leninskie gory 1–2, Moscow 119991 (Russian Federation); Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilova 28, Moscow 119991 (Russian Federation); Chaschin, Ivan S. [Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilova 28, Moscow 119991 (Russian Federation); Khokhlova, Marina A. [Faculty of Physics, Lomonosov Moscow State University, Leninskie gory 1–2, Moscow 119991 (Russian Federation); Grigorev, Timofey E. [Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilova 28, Moscow 119991 (Russian Federation); Bakuleva, Natalia P.; Lyutova, Irina G.; Kondratenko, Janna E. [Bakulev Scientific Center for Cardiovascular Surgery of the Russian Academy of Medical Sciences, Roublyevskoe Sh. 135, Moscow 121552 (Russian Federation); Badun, Gennadii A.; Chernysheva, Maria G. [Radiochemistry Division, Faculty of Chemistry, Lomonosov Moscow State University, Leninskie gory 1–2, Moscow 119991 (Russian Federation); Khokhlov, Alexei R. [Faculty of Physics, Lomonosov Moscow State University, Leninskie gory 1–2, Moscow 119991 (Russian Federation); Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilova 28, Moscow 119991 (Russian Federation)

    2014-04-01

    Calcification of bovine pericardium dramatically shortens typical lifetimes of biological prosthetic heart valves and thus precludes their choice for younger patients. The aim of the present work is to demonstrate that the calcification is to be mitigated by means of treatment of bovine pericardium in solutions of chitosan in carbonic acid, i.e. water saturated with carbon dioxide at high pressure. This acidic aqueous fluid unusually combines antimicrobial properties with absolute biocompatibility as far as at normal pressure it decomposes spontaneously and completely into H{sub 2}O and CO{sub 2}. Yet, at high pressures it can protonate and dissolve chitosan materials with different degrees of acetylation (in the range of 16–33%, at least) without any further pretreatment. Even exposure of the bovine pericardium in pure carbonic acid solution without chitosan already favours certain reduction in calcification, somewhat improved mechanical properties, complete biocompatibility and evident antimicrobial activity of the treated collagen tissue. The reason may be due to high extraction ability of this peculiar compressed fluidic mixture. Moreover, exposure of the bovine pericardium in solutions of chitosan in carbonic acid introduces even better mechanical properties and highly pronounced antimicrobial activity of the modified collagen tissue against adherence and biofilm formation of relevant Gram-positive and Gram-negative strains. Yet, the most important achievement is the detected dramatic reduction in calcification for such modified collagen tissues in spite of the fact that the amount of the thus introduced chitosan is rather small (typically ca. 1 wt.%), which has been reliably detected using original tritium labelling method. We believe that these improved properties are achieved due to particularly deep and uniform impregnation of the collagen matrix with chitosan from its pressurised solutions in carbonic acid. - Highlights: • Treatment of GA

  11. Impact of recipient-related factors on structural dysfunction of xenoaortic bioprosthetic heart valves

    Directory of Open Access Journals (Sweden)

    Barbarash O

    2015-03-01

    Full Text Available Olga Barbarash, Natalya Rutkovskaya, Oksana Hryachkova, Olga Gruzdeva, Evgenya Uchasova, Anastasia Ponasenko, Natalya Kondyukova, Yuri Odarenko, Leonid Barbarash Federal State Budgetary Scientific Institution Research Institute for Complex Issues of Cardiovascular Diseases, Kemerovo, Russia Objective: To analyze the influence of recipient-related metabolic factors on the rate of structural dysfunction caused by the calcification of xenoaortic bioprostheses. Materials and methods: We retrospectively analyzed clinical status, calcium–phosphorus metabolism, and nonspecific markers of inflammatory response in bioprosthetic mitral valve recipients with calcific degeneration confirmed by histological and electron microscopic studies (group 1, n=22, and in those without degeneration (group 2, n=48. Results: Patients with confirmed calcification of bioprostheses were more likely to have a severe clinical state (functional class IV in 36% in group 1 versus 15% in group 2, P=0.03 and a longer cardiopulmonary bypass period (112.8±18.8 minutes in group 1 versus 97.2±23.6 minutes in group 2, P=0.02 during primary surgery. Patients in group 1 demonstrated moderate hypovitaminosis D (median 34.0, interquartile range [21.0; 49.4] vs 40 [27.2; 54.0] pmol/L, P>0.05, osteoprotegerin deficiency (82.5 [44.2; 115.4] vs 113.5 [65.7; 191.3] pg/mL, P>0.05 and osteopontin deficiency (4.5 [3.3; 7.7] vs 5.2 [4.1; 7.2] ng/mL, P>0.05, and significantly reduced bone-specific alkaline phosphatase isoenzyme (17.1 [12.2; 21.4] vs 22.3 [15.5; 30.5] U/L, P=0.01 and interleukin-8 levels (9.74 [9.19; 10.09] pg/mL vs 13.17 [9.72; 23.1] pg/mL, P=0.045 compared with group 2, with an overall increase in serum levels of proinflammatory markers. Conclusion: Possible predictors of the rate of calcific degeneration of bioprostheses include the degree of decompensated heart failure, the duration and invasiveness of surgery, and the characteristics of calcium–phosphorus homeostasis in

  12. Micro Particle Image Velocimetry Measurements of Steady Diastolic Leakage Flow in the Hinge of a St. Jude Medical® Regent™ Mechanical Heart Valve

    OpenAIRE

    Jun, Brian H.; Saikrishnan, Neelakantan; Yoganathan, Ajit P.

    2013-01-01

    A number of clinical, in vitro and computational studies have shown the potential for thromboembolic complications in bileaflet mechanical heart valves (BMHV), primarily due to the complex and unsteady flows in the valve hinges. These studies have focused on quantitative and qualitative parameters such as velocity magnitude, turbulent shear stresses, vortex formation and platelet activation to identify potential for blood damage. However, experimental characterization of the whole flow fields...

  13. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... opens freely when the heart contracts. On the right, we see a picture of the aortic valve ... the aortic valve because the probe is sitting right behind the aortic valve. Lots of patients on ...

  14. Blood damage through a bileaflet mechanical heart valve: a quantitative computational study using a multiscale suspension flow solver.

    Science.gov (United States)

    Min Yun, B; Aidun, Cyrus K; Yoganathan, Ajit P

    2014-10-01

    Bileaflet mechanical heart valves (BMHVs) are among the most popular prostheses to replace defective native valves. However, complex flow phenomena caused by the prosthesis are thought to induce serious thromboembolic complications. This study aims at employing a novel multiscale numerical method that models realistic sized suspended platelets for assessing blood damage potential in flow through BMHVs. A previously validated lattice-Boltzmann method (LBM) is used to simulate pulsatile flow through a 23 mm St. Jude Medical (SJM) Regent™ valve in the aortic position at very high spatiotemporal resolution with the presence of thousands of suspended platelets. Platelet damage is modeled for both the systolic and diastolic phases of the cardiac cycle. No platelets exceed activation thresholds for any of the simulations. Platelet damage is determined to be particularly high for suspended elements trapped in recirculation zones, which suggests a shift of focus in blood damage studies away from instantaneous flow fields and toward high flow mixing regions. In the diastolic phase, leakage flow through the b-datum gap is shown to cause highest damage to platelets. This multiscale numerical method may be used as a generic solver for evaluating blood damage in other cardiovascular flows and devices. PMID:25070372

  15. Patient-specific simulation of a trileaflet aortic heart valve in a realistic left ventricle and aorta

    Science.gov (United States)

    Gilmanov, Anvar; Le, Trung; Stolarski, Henryk; Sotiropoulos, Fotis

    2013-11-01

    We develop a patient-specific model of the left ventricle consisting of: (1) magnetic-resonance images (MRI) data for wall geometry and kinematics reconstruction of the left ventricle during one cardiac cycle and (2) an elastic trileaflet aortic heart valve implanted in (3) a realistic aorta interacting with blood flow driven by the pulsating left ventricle. Blood flow is simulated via a new fluid-structure interaction (FSI) method, which couples the sharp-interface CURVIB [L. Ge, F. Sotiropoulos, JCP, (2007)] for handling complex moving boundaries with a new, rotation-free finite-element (FE) formulation for simulating large tissue deformations [H. Stolarski, A. Gilmanov, F. Sotiropoulos, IJNME, (2013)] The new FE shell formulation has been extensively tested and validated for a range of relevant problems showing good agreements. Validation of the coupled FSI-FE-CURVIB model is carried out for a thin plate undergoing flow-induced vibrations in the wake of a square cylinder and the computed results are in good agreement with published data. The new approach has been applied to simulate dynamic interaction of a trileaflet aortic heart valve with pulsating blood flow at physiological conditions and realistic artery and left ventricle geometry.

  16. Surface modification of polyurethane films by plasma and ultraviolet light to improve haemocompatibility for artificial heart valves.

    Science.gov (United States)

    Alves, P; Cardoso, R; Correia, T R; Antunes, B P; Correia, I J; Ferreira, P

    2014-01-01

    Prosthetic cardiac valves implantation is a common procedure used to treat heart valve diseases. Although there are different prostheses already available in the market (either mechanical or bioprosthetic), their use presents several problems, specifically concerning thrombogenicity and structural failure. Recently, some progresses have been achieved in developing heart valves based on synthetic materials with special emphasis in polymers. Among them, polyurethanes are one of the most commonly used for the production of these devices. Herein, Elastollan(®)1180A50, a thermoplastic polyurethane (TPU), was used to formulate films whose surfaces were modified by grafting 2-hydroxyethylmethacrylate (HEMA) either by ultra-violet (UV) or by plasma treatment. All films were analyzed before and after grafting. X-ray photoelectron spectroscopy (XPS) measurements were used to evaluate TPU surfaces functionalization. HEMA grafting was confirmed by the increase of the hydroxyl (OH) groups' concentration at the surface of the films. Atomic force microscopy (AFM) analysis was done to evaluate the surface topography of the biomaterials. Results showed that the roughness of the surface decreased when HEMA was grafted, especially for plasma treated samples. After grafting the films' hydrophilicity was improved, as well as the polar component of the surface energy, by 15-30%. Hydrophobic recovery studies using milli Q water or PBS were also performed to characterize the stability of the modified surface, showing that the films maintained their surface properties along time. Furthermore, blood-contact tests were performed to evaluate haemolytic and thrombogenic potential. The results obtained for HEMA grafted surfaces, using plasma treatment, confirmed biomaterials biocompatibility and low thrombogenicity. Finally, the cytotoxicity and antibacterial activity of the materials was assessed through in vitro assays for both modified films. The obtained results showed enhanced

  17. Aortic Valve Disease

    Science.gov (United States)

    ... valve opens when the left ventricle squeezes to pump out blood, and closes in between heart beats to keep ... the left ventricle has to work harder to pump blood out through the valve. To do this extra ...

  18. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... of that slide, that demonstrates that patients with New York Heart Association class heart failure 1 and ... right down the aortic valve and that's the new aortic valve that Dr. Streitman's placed. And you ...

  19. Mitral Valve Perforation in Libman-Sacks Endocarditis: A Heart-Wrenching Case of Lupus.

    Science.gov (United States)

    Aby, Elizabeth S; Rosol, Zachary; Simegn, Mengistu A

    2016-08-01

    Libman-Sacks (LS) endocarditis is one of the most common cardiac manifestations of systemic lupus erythematosus. Rarely, however, it can lead to serious complications, including severe valvular regurgitation or superimposed bacterial endocarditis. We describe the initial diagnostic challenges, clinical course, imaging studies and histopathological findings of a patient who presented with life-threatening lupus complicated by hemoptysis and respiratory failure secondary to a rare complication of LS endocarditis, acute mitral valve perforation. We review the current literature on valve perforation in the setting of LS endocarditis. In conclusion, although the disease is often asymptomatic and hemodynamically insignificant, it can result in serious and potentially fatal complications secondary to valve perforation, which may demand emergency surgical management. PMID:26976291

  20. Low standard oral anticoagulation therapy for Chinese patients with St.Jude mechanical heart valves

    Institute of Scientific and Technical Information of China (English)

    孙晓刚; 胡盛寿; 祁国奇; 周玉燕

    2003-01-01

    Objective To study the efficacy of the low standard oral anticoagulation therapy following St Jude Medical (SJM) valve implantation for Chinese patients.Methods Totally 805 patients with a mean age of 42.70±11.09 years, enrolled into this study. Among them, 230 underwent aortic valve replacements (AVR), 381 mitral valve replacements (MVR), 189 double valve replacements (DVR) and 5 tricuspid valve replacememts (TVR). All patients received postoperative oral anticoagulation therapy based on a low standard of international normalized ratio (INR, 2.0-2.5). Of the 805 patients, 710 were followed up for 0.25-13 years (a median, 4.15 years). Results Postoperatively, 17 adverse events occurred. Operative mortality was 2.11%. The most frequent cause of operative mortality was a low cardiac output. During follow-up, there were 47 anticoagulant-induced hemorrhages [1.59%/patient-year (pt-yr)], 10 cases of thromboembolism (0.34%/pt-yr), and 3 mechanical valve thromboses (0.19%/pt-yr). There were 44 late deaths and the linearized late mortality rates were 0.51%pt-yr. Estimates of actuarial survival for all patients at 5 and 10 years was 97.45% (0.70%) and 77.96% (17.44%), respectively.Conclusions A low target INR range of 2.0-2.5 is preferable for Chinese patients so as to reduce the severe bleeding complications in those with conventionally higher levels of INR. The long-term results were satisfactory in terms of the numbers of those who suffered thrombosis, embolism and bleeding.

  1. Are the Current Doppler Echocardiography Criteria Able to Discriminate Mitral Bileaflet Mechanical Heart Valve Malfunction? An In Vitro Study.

    Science.gov (United States)

    Evin, Morgane; Guivier-Curien, Carine; Pibarot, Philippe; Kadem, Lyes; Rieu, Régis

    2016-05-01

    Malfunction of bileaflet mechanical heart valves in the mitral position could either be due to patient-prosthesis mismatch (PPM) or leaflet obstruction. The aim of this article is to investigate the validity of current echocardiographic criteria used for diagnosis of mitral prosthesis malfunction, namely maximum velocity, mean transvalvular pressure gradient, effective orifice area, and Doppler velocity index. In vitro testing was performed on a double activation left heart duplicator. Both PPM and leaflet obstruction were investigated on a St. Jude Medical Master. PPM was studied by varying the St. Jude prosthesis size (21, 25, and 29 mm) and stroke volume (70 and 90 mL). Prosthesis leaflet obstruction was studied by partially or totally blocking the movement of one valve leaflet. Mitral flow conditions were altered in terms of E/A ratios (0.5, 1.0, and 1.5) to simulate physiologic panel of diastolic function. Maximum velocity, effective orifice area, and Doppler velocity index are shown to be insufficient to distinguish normal from malfunctioning St. Jude prostheses. Doppler velocity index and effective orifice area were 1.3 ± 0.49 and 1.83 ± 0.43 cm(2) for testing conditions with no malfunction below the 2.2 and 2 cm(2) thresholds (1.19 cm(2) for severe PPM and 1.23 cm(2) for fully blocked leaflet). The mean pressure gradient reached 5 mm Hg thresholds for several conditions of severe PPM only (6.9 mm Hg and mean maximum velocity value: 183.4 cm/s) whereas such value was never attained in the case of leaflet obstruction. In the case of leaflet obstruction, the maximum velocity averaged over the nine pulsed-wave Doppler locations increased by 38% for partial leaflet obstruction and 75% for a fully blocked leaflet when compared with normal conditions. Current echocardiographic criteria might be suboptimal for the detection of bileaflet mechanical heart valve malfunction. Further developments and investigations are required in order

  2. Changes in heart valve structure and function in patients treated with dopamine agonists for prolactinomas, a 2-year follow-up study.

    NARCIS (Netherlands)

    Delgado, V.; Biermasz, N.R.; Thiel, S.W. van; Ewe, S.H.; Marsan, N.A.; Holman, E.R.; Feelders, R.A.; Smit, J.W.A.; Bax, J.J.; Pereira, A.M.

    2012-01-01

    OBJECTIVE: The use of ergot-derived dopamine agonists (DA) to treat patients with prolactinomas has not been associated with an increased risk of significant heart valve dysfunction. Accordingly, the present study evaluated whether the long-term use of DA for hyperprolactinaemia may be associated wi

  3. The Progress of Tissue Engineering Heart Valve%组织工程心脏瓣膜构建现状与发展

    Institute of Scientific and Technical Information of China (English)

    赵东锷; 刘维永

    2001-01-01

    The currently used heart valve prosthesis are still far from the ideal one in anticoagulation and longevity. The construction of tissue engineering heart valve leaflets are carried out recently. This article reviews the progress of tissue engineering heart valve leaflets in implanting materials, seeded cells, animal experiment and basic research. It also discusses the benefits and feasibility of tissue engineering heart valve leaflets.%为了克服目前临床应用的人工心脏瓣膜在抗凝和衰坏方面的缺点,随着组织工程学的发展,构建组织工程心脏瓣膜的研究已取得初步进展。综述近年来组织工程心脏瓣膜在种植材料、种子细胞、动物实验和基础研究方面取得的进展,并探讨组织工程心脏瓣膜的优越性和可行性。

  4. Heart Rate Variability in Cavalier King Charles Spaniels with Different Degree of Myxomatous Mitral Valve Disease

    DEFF Research Database (Denmark)

    Rasmussen, Caroline Elisabeth; Falk, Bo Torkel; Zois, Nora Elisabeth;

    2010-01-01

    Sciences, University of Copenhagen, Frederiksberg, Denmark, 2Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden; and 3Novo Nordic A/S, Maaloev, Denmark. Introduction: Modulation of heart rate by the autonomic nervous system can indirectly be measured by heart rate...

  5. Increased serum C-reactive protein concentrations in dogs with congestive heart failure due to myxomatous mitral valve disease

    DEFF Research Database (Denmark)

    Reimann, M. J.; Ljungvall, I.; Hillstrom, A.;

    2016-01-01

    Cardiovascular disease in humans and dogs is associated with mildly increased circulating concentrations of C-reactive protein (CRP). Few studies have evaluated associations between circulating CRP and canine myxomatous mitral valve disease (MMVD) and the results reported have been divergent....... The aim of this study was to investigate whether serum concentrations of CRP, determined using a novel automated canine-specific high -sensitivity CRP assay (Gentian hsCRP), were associated with severity of MMVD and selected clinical variables in dogs. The study included 188 client-owned dogs...... with different severities of MMVD. Dogs were classified based on ACVIM consensus statement guidelines (group A, n = 58; group BI, n = 56; group B2, n = 38; group C, n = 36). Data were analysed using descriptive statistics and multiple regression analysis. Dogs with congestive heart failure (CHF; group C) had...

  6. Multivariate Normal Tissue Complication Probability Modeling of Heart Valve Dysfunction in Hodgkin Lymphoma Survivors

    Energy Technology Data Exchange (ETDEWEB)

    Cella, Laura, E-mail: laura.cella@cnr.it [Institute of Biostructures and Bioimaging, National Council of Research, Naples (Italy); Department of Advanced Biomedical Sciences, Federico II University School of Medicine, Naples (Italy); Liuzzi, Raffaele; Conson, Manuel [Institute of Biostructures and Bioimaging, National Council of Research, Naples (Italy); Department of Advanced Biomedical Sciences, Federico II University School of Medicine, Naples (Italy); D’Avino, Vittoria [Institute of Biostructures and Bioimaging, National Council of Research, Naples (Italy); Salvatore, Marco [Department of Advanced Biomedical Sciences, Federico II University School of Medicine, Naples (Italy); Pacelli, Roberto [Institute of Biostructures and Bioimaging, National Council of Research, Naples (Italy); Department of Advanced Biomedical Sciences, Federico II University School of Medicine, Naples (Italy)

    2013-10-01

    Purpose: To establish a multivariate normal tissue complication probability (NTCP) model for radiation-induced asymptomatic heart valvular defects (RVD). Methods and Materials: Fifty-six patients treated with sequential chemoradiation therapy for Hodgkin lymphoma (HL) were retrospectively reviewed for RVD events. Clinical information along with whole heart, cardiac chambers, and lung dose distribution parameters was collected, and the correlations to RVD were analyzed by means of Spearman's rank correlation coefficient (Rs). For the selection of the model order and parameters for NTCP modeling, a multivariate logistic regression method using resampling techniques (bootstrapping) was applied. Model performance was evaluated using the area under the receiver operating characteristic curve (AUC). Results: When we analyzed the whole heart, a 3-variable NTCP model including the maximum dose, whole heart volume, and lung volume was shown to be the optimal predictive model for RVD (Rs = 0.573, P<.001, AUC = 0.83). When we analyzed the cardiac chambers individually, for the left atrium and for the left ventricle, an NTCP model based on 3 variables including the percentage volume exceeding 30 Gy (V30), cardiac chamber volume, and lung volume was selected as the most predictive model (Rs = 0.539, P<.001, AUC = 0.83; and Rs = 0.557, P<.001, AUC = 0.82, respectively). The NTCP values increase as heart maximum dose or cardiac chambers V30 increase. They also increase with larger volumes of the heart or cardiac chambers and decrease when lung volume is larger. Conclusions: We propose logistic NTCP models for RVD considering not only heart irradiation dose but also the combined effects of lung and heart volumes. Our study establishes the statistical evidence of the indirect effect of lung size on radio-induced heart toxicity.

  7. Time-dependent biaxial mechanical behavior of the aortic heart valve leaflet.

    Science.gov (United States)

    Stella, John A; Liao, Jun; Sacks, Michael S

    2007-01-01

    Despite continued progress in the treatment of aortic valve (AV) disease, current treatments continue to be challenged to consistently restore AV function for extended durations. Improved approaches for AV repair and replacement rests upon our ability to more fully comprehend and simulate AV function. While the elastic behavior the AV leaflet (AVL) has been previously investigated, time-dependent behaviors under physiological biaxial loading states have yet to be quantified. In the current study, we performed strain rate, creep, and stress-relaxation experiments using porcine AVL under planar biaxial stretch and loaded to physiological levels (60 N/m equi-biaxial tension), with strain rates ranging from quasi-static to physiologic. The resulting stress-strain responses were found to be independent of strain rate, as was the observed low level of hysteresis ( approximately 17%). Stress relaxation and creep results indicated that while the AVL exhibited significant stress relaxation, it exhibited negligible creep over the 3h test duration. These results are all in accordance with our previous findings for the mitral valve anterior leaflet (MVAL) [Grashow, J.S., Sacks, M.S., Liao, J., Yoganathan, A.P., 2006a. Planar biaxial creep and stress relaxatin of the mitral valve anterior leaflet. Annals of Biomedical Engineering 34 (10), 1509-1518; Grashow, J.S., Yoganathan, A.P., Sacks, M.S., 2006b. Biaxial stress-stretch behavior of the mitral valve anterior leaflet at physiologic strain rates. Annals of Biomedical Engineering 34 (2), 315-325], and support our observations that valvular tissues are functionally anisotropic, quasi-elastic biological materials. These results appear to be unique to valvular tissues, and indicate an ability to withstand loading without time-dependent effects under physiologic loading conditions. Based on a recent study that suggested valvular collagen fibrils are not intrinsically viscoelastic [Liao, J., Yang, L., Grashow, J., Sacks, M.S., 2007

  8. Ultrasound-targeted transfection of tissue-type plasminogen activator gene carried by albumin nanoparticles to dog myocardium to prevent thrombosis after heart mechanical valve replacement

    Directory of Open Access Journals (Sweden)

    Ji J

    2012-06-01

    Full Text Available Ji Jun, Ji Shang-Yi, Yang Jian-An, He Xia, Yang Xiao-Han, Ling Wen-Ping, Chen Xiao-LingDepartment of Pathology and Cardiovascular Surgery, Shenzhen Sun Yat-Sen Cardiovascular Hospital, Shenzhen, Guangdong, People's Republic of ChinaBackground: There are more than 300,000 prosthetic heart valve replacements each year worldwide. These patients are faced with a higher risk of thromboembolic events after heart valve surgery and long-term or even life-long anticoagulative and antiplatelet therapies are necessary. Some severe complications such as hemorrhaging or rebound thrombosis can occur when the therapy ceases. Tissue-type plasminogen activator (t-PA is a thrombolytic agent. One of the best strategies is gene therapy, which offers a local high expression of t-PA over a prolonged time period to avoid both systemic hemorrhaging and local rebound thrombosis. There are some issues with t-PA that need to be addressed: currently, there is no up-to-date report on how the t-PA gene targets the heart in vivo and the gene vector for t-PA needs to be determined.Aims: To fabricate an albumin nano-t-PA gene ultrasound-targeted agent and investigate its targeting effect on prevention of thrombosis after heart mechanic valve replacement under therapeutic ultrasound.Methods: A dog model of mechanical tricuspid valve replacement was constructed. A highly expressive t-PA gene plasmid was constructed and packaged by nanoparticles prepared with bovine serum albumin. This nanopackaged t-PA gene plasmid was further cross-linked to ultrasonic microbubbles prepared with sucrose and bovine serum albumin to form the ultrasonic-targeted agent for t-PA gene transfection. The agent was given intravenously followed by a therapeutic ultrasound treatment (1 MHz, 1.5 w/cm2, 10 minutes of the heart soon after valve replacement had been performed. The expression of t-PA in myocardium was detected with multiclonal antibodies to t-PA by the indirect immunohistochemical method

  9. On intrinsic stress fiber contractile forces in semilunar heart valve interstitial cells using a continuum mixture model.

    Science.gov (United States)

    Sakamoto, Yusuke; Buchanan, Rachel M; Sacks, Michael S

    2016-02-01

    Heart valve interstitial cells (VICs) play a critical role in the maintenance and pathophysiology of heart valve tissues. Normally quiescent in the adult, VICs can become activated in periods of growth and disease. When activated, VICs exhibit increased levels of cytokines and extracellular matrix (ECM) synthesis, and upregulated expression and strong contraction of α-smooth muscle actin (α-SMA) fibers. However, it remains unknown how expression and contraction of the α-SMA fibers, which vary among different VIC types, contribute to the overall VIC mechanical responses, including the nucleus and cytoskeleton contributions. In the present study, we developed a novel solid-mixture model for VIC biomechanical behavior that incorporated 1) the underlying cytoskeletal network, 2) the oriented α-SMA stress fibers with passive elastic and active contractile responses, 3) a finite deformable elastic nucleus. We implemented the model in a full 3D finite element simulation of a VIC based on known geometry. Moreover, we examined the respective mechanical responses of aortic and pulmonary VICs (AVICs and PVICs, respectively), which are known to have different levels of α-SMA expression levels and contractile behaviors. To calibrate the model, we simulated the combined mechanical responses of VICs in both micropipette aspiration (MA) and atomic force microscopy (AFM) experiments. These two states were chosen as the VICs were under significantly different mechanical loading conditions and activation states, with the α-SMA fibers inactivated in the MA studies while fully activated in the AFM studies. We also used the AFM to study the mechanical property of the nucleus. Our model predicted that the substantial differences found in stiffening of the AVIC compared to the PVICs was due to a 9 to 16 times stronger intrinsic AVIC α-SMA stress fiber contractile force. Model validation was done by simulating a traction force microscopy experiment to estimate the forces the VICs

  10. Mitral valve regurgitation

    Science.gov (United States)

    ... MVP) Rare conditions, such as untreated syphilis or Marfan syndrome Rheumatic heart disease. This is a complication ... the arteries Heart failure - overview High blood pressure Marfan syndrome Mitral valve prolapse Pulmonary embolus Stroke Update ...

  11. Heart Team therapeutic decision-making and treatment in severe aortic valve stenosis

    DEFF Research Database (Denmark)

    Thyregod, Hans Gustav Hørsted; Holmberg, Fredrik; Gerds, Thomas Alexander;

    2016-01-01

    %), and surgical aortic valve replacement (SAVR) in 392 (81%) of patients. In patients referred to intervention, TAVI compared with SAVR patients were older (OR = 1.17 per year, 95% CI 1.09-1.26; p coronary artery bypass surgery (OR = 385, 79-2738; p obesity (OR = 4.69, 1.......51-13.77; p disease (COPD) (OR = 3.66, 1.21-10.75; p = 0.02). MT patients compared with patients referred to any intervention were older, had a higher prevalence of COPD, peripheral arterial disease, previous myocardial infarction, and cerebrovascular disease...

  12. Heart valve disease associated with treatment with ergot-derived dopamine agonists: a clinical and echocardiographic study of patients with Parkinson's disease

    DEFF Research Database (Denmark)

    Rasmussen, Vibeke Guldbrand; Poulsen, Steen Hvitfeldt; Dupont, E;

    2007-01-01

    regurgitation (n = 5) was found in 22 EDDA patients (25.9%). Two patients had coexistent moderate mitral and tricuspid valvular regurgitation. Two non-EDDA patients had moderate valve insufficiency (3.8%, P insufficiency in the EDDA patients was 7....... Interventions. Patients were screened for valvular heart disease by clinical means and by examiner-blinded echocardiography. Main outcome measure was valvular regurgitation revealed by echocardiography. RESULTS: Severe aortic regurgitation (n = 4) or moderate aortic (n = 12), mitral (n = 3) or tricuspidal valve...

  13. Novel heart valve prosthesis with self-endothelialization potential made of modified polyhedral oligomeric silsesquioxane-nanocomposite material.

    Science.gov (United States)

    Ghanbari, Hossein; Radenkovic, Dina; Marashi, Sayed Mahdi; Parsno, Shirin; Roohpour, Nima; Burriesci, Gaetano; Seifalian, Alexander M

    2016-06-01

    In the cardiovascular system, the endothelial layer provides a natural antithrombogenic surface on the inner portion of the heart and associated vessels. For a synthetic material therefore, the ability to attract and retain endothelial or endothelial progenitor cells (EPCs), ultimately creating a single endothelial layer on its surface, is of prime importance. The authors have developed a nanocomposite polymer, based on a combination of polyhedral oligomeric silsesquioxane nanoparticles and polycarbonate urea urethane (POSS-PCU), which is biocompatible and has been used in human for the world's first synthetic trachea, tear duct, and bypass graft. In this study, the authors modified the surface of this casted nanocomposite by grafting fibronectin derived bioactive peptides [glycine-arginine-glycine-aspartic acid-glycine (GRGDG) and lauric acid conjugated GRGDG (GRGDG-LA)] to enhance the endothelialization for using heart valves leaflets from circulating EPCs. Human peripheral blood mononuclear cells were separated using Ficoll-Paque centrifugation, with harvested EPCs purified using CD34 microbead labeling and magnetic-activated cell sorting. Cells were seeded onto 96 well plates coated with POSS-PCU, GRGDG/GRGDG-LA modified POSS-PCU and PCU polymers, for a period of 21 days. Cells were studied under light, confocal, and scanning electron microscope (SEM). Fluorescence-activated cell sorting was used to analyze cell surface markers. Cell attachment and proliferation was observed in all POSS-PCU samples, significantly higher than the activity seen within the control PCU polymers (p < 0.05). Microscopic examination revealed clonal expansion and morphological changes in cells seeded on POSS-PCU. The cells expressed increasing levels of mature endothelial cell markers over time with a concurrent reduction in hematopoietic stem cell marker expression. SEM showed a mixed population of morphologically differentiated endothelial cells and EPCs. These results support

  14. Mitral valve repair and redo repair for mitral regurgitation in a heart transplant recipient

    Directory of Open Access Journals (Sweden)

    Bouma Wobbe

    2012-09-01

    Full Text Available Abstract A 37-year-old man with end-stage idiopathic dilated cardiomyopathy underwent an orthotopic heart transplant followed by a reoperation with mitral annuloplasty for severe mitral regurgitation. Shortly thereafter, he developed severe tricuspid regurgitation and severe recurrent mitral regurgitation due to annuloplasty ring dehiscence. The dehisced annuloplasty ring was refixated, followed by tricuspid annuloplasty through a right anterolateral thoracotomy. After four years of follow-up, there are no signs of recurrent mitral or tricupid regurgitation and the patient remains in NYHA class II. Pushing the envelope on conventional surgical procedures in marginal donor hearts (both before and after transplantation may not only improve the patient’s functional status and reduce the need for retransplantation, but it may ultimately alleviate the chronic shortage of donor hearts.

  15. Transcatheter CoreValve valve-in-valve implantation in a stentless porcine aortic valve for severe aortic regurgitation

    OpenAIRE

    Yong, Celina M; Buchbinder, Maurice; Giacomini, John C

    2014-01-01

    Key Clinical Message We describe the first valve-in-valve Corevalve transcatheter aortic valve replacement in the St. Jude Toronto stentless porcine aortic valve in the United States, which enabled this 59-year-old patient with a history of bacterial endocarditis and aortic regurgitation to avoid heart transplant with complete resolution of his severe left ventricular dysfunction.

  16. Diseases of the Tricuspid Valve

    Science.gov (United States)

    ... Myocarditis Obstructive Sleep Apnea Pericarditis Peripheral Vascular Disease Rheumatic Fever Sick Sinus Syndrome Silent Ischemia Stroke Sudden Cardiac Arrest Valve Disease Vulnerable Plaque Diseases of the Tricuspid Valve | Share Diseases of the heart valves are grouped according to which valve or ...

  17. Cytochrome P450 (CYP2C9FNx012,FNx013 & vitamin-K epoxide reductase complex (VKORC1 -1639G < A gene polymorphisms & their effect on acenocoumarol dose in patients with mechanical heart valve replacement

    Directory of Open Access Journals (Sweden)

    Anupriya Kaur

    2013-01-01

    Interpretation & conclusions: The study findings point towards the role of CYP2C9 and VKORC1 gene polymorphisms in determining the inter-individual dose variability of acenocoumarol in the Indian patients with mechanical heart valve replacement.

  18. Closing sounds and related complaints after heart valve replacement with St Jude Medical, Duromedics Edwards, Björk-Shiley Monostrut, and Carbomedics prostheses.

    OpenAIRE

    Moritz, A.; Steinseifer, U; Kobinia, G; Neuwirth-Riedl, K; Wolters, H.; H. Reul; Wolner, E

    1992-01-01

    OBJECTIVE--To measure the noise produced and related subjective complaints after implantation of four different mechanical heart valve prostheses and to identify further factors related to the patient and prosthesis that influence noise generation and complaints. DESIGN--Sound pressure was measured 5 and 10 cm and 1 m from the point of maximal impulse on the body surface by a calibrated meter in quiet rooms with either a decibel(A) filter or octave filters. The patients were asked about their...

  19. Effect of Hinge Gap Width of a St. Jude Medical Bileaflet Mechanical Heart Valve on Blood Damage Potential—An In Vitro Micro Particle Image Velocimetry Study

    OpenAIRE

    Jun, Brian H.; Saikrishnan, Neelakantan; Arjunon, Sivakkumar; Min Yun, B.; Yoganathan, Ajit P.

    2014-01-01

    The hinge regions of the bileaflet mechanical heart valve (BMHV) can cause blood element damage due to nonphysiological shear stress levels and regions of flow stasis. Recently, a micro particle image velocimetry (μPIV) system was developed to study whole flow fields within BMHV hinge regions with enhanced spatial resolution under steady leakage flow conditions. However, global velocity maps under pulsatile conditions are still necessary to fully understand the blood damage potential of these...

  20. Left Main Percutaneous Coronary Intervention and Transcatheter Aortic Valve Replacement in a Young Male with Rheumatic Heart Disease and Porcelain Aorta

    OpenAIRE

    Chainani, Vinod; Perez, Osman; Hanno, Ram; Hourani, Patrick; Rengifo-Moreno, Pablo; Martinez-Clark, Pedro; Alfonso, Carlos E.

    2016-01-01

    We highlight the presence of a calcified mass in the left main coronary artery without significant atherosclerosis seen in the other coronary arteries or in the peripheral large arteries. In our view, the calcified character of the obstruction and the calcification of the aortic valve are characteristic of a variant type of coronary artery disease (CAD) not associated with the same risk factors as diffuse coronary atherosclerosis, but, in this case, with rheumatic heart disease. This case rep...

  1. Characterization of three-dimensional anisotropic heart valve tissue mechanical properties using inverse finite element analysis.

    Science.gov (United States)

    Abbasi, Mostafa; Barakat, Mohammed S; Vahidkhah, Koohyar; Azadani, Ali N

    2016-09-01

    Computational modeling has an important role in design and assessment of medical devices. In computational simulations, considering accurate constitutive models is of the utmost importance to capture mechanical response of soft tissue and biomedical materials under physiological loading conditions. Lack of comprehensive three-dimensional constitutive models for soft tissue limits the effectiveness of computational modeling in research and development of medical devices. The aim of this study was to use inverse finite element (FE) analysis to determine three-dimensional mechanical properties of bovine pericardial leaflets of a surgical bioprosthesis under dynamic loading condition. Using inverse parameter estimation, 3D anisotropic Fung model parameters were estimated for the leaflets. The FE simulations were validated using experimental in-vitro measurements, and the impact of different constitutive material models was investigated on leaflet stress distribution. The results of this study showed that the anisotropic Fung model accurately simulated the leaflet deformation and coaptation during valve opening and closing. During systole, the peak stress reached to 3.17MPa at the leaflet boundary while during diastole high stress regions were primarily observed in the commissures with the peak stress of 1.17MPa. In addition, the Rayleigh damping coefficient that was introduced to FE simulations to simulate viscous damping effects of surrounding fluid was determined. PMID:27173827

  2. Biomarkers in Cardiology - Part 2: In Coronary Heart Disease, Valve Disease and Special Situations

    Directory of Open Access Journals (Sweden)

    2015-05-01

    Full Text Available Cardiovascular diseases are the main causes of mortality and morbidity in Brazil. Their primary and secondary preventions are a priority for the health system and require multiple approaches for increased effectiveness. Biomarkers are tools used to identify with greater accuracy high-risk individuals, establish a faster diagnosis, guide treatment, and determine prognosis. This review aims to highlight the importance of biomarkers in clinical cardiology practice and raise relevant points regarding their application and perspectives for the next few years. This document was divided into two parts. This second part addresses the application of biomarkers in coronary heart disease, valvular diseases, cardio-oncology, pulmonary embolism, and cardiorenal syndrome.

  3. Simulation of the three-dimensional hinge flow fields of a bileaflet mechanical heart valve under aortic conditions.

    Science.gov (United States)

    Simon, Hélène A; Ge, Liang; Borazjani, Iman; Sotiropoulos, Fotis; Yoganathan, Ajit P

    2010-03-01

    Thromboembolic complications of bileaflet mechanical heart valves (BMHV) are believed to be due to detrimental stresses imposed on blood elements by the hinge flows. Characterization of these flows is thus crucial to identify the underlying causes for complications. In this study, we conduct three-dimensional pulsatile flow simulations through the hinge of a BMHV under aortic conditions. Hinge and leaflet geometries are reconstructed from the Micro-Computed Tomography scans of a BMHV. Simulations are conducted using a Cartesian sharp-interface immersed-boundary methodology combined with a second-order accurate fractional-step method. Physiologic flow boundary conditions and leaflet motion are extracted from the Fluid-Structure Interaction simulations of the bulk of the flow through a BMHV. Calculations reveal the presence, throughout the cardiac cycle, of flow patterns known to be detrimental to blood elements. Flow fields are characterized by: (1) complex systolic flows, with rotating structures and slow reverse flow pattern, and (2) two strong diastolic leakage jets accompanied by fast reverse flow at the hinge bottom. Elevated shear stresses, up to 1920 dyn/cm2 during systole and 6115 dyn/cm2 during diastole, are reported. This study underscores the need to conduct three-dimensional simulations throughout the cardiac cycle to fully characterize the complexity and thromboembolic potential of the hinge flows. PMID:19960368

  4. Swan-Ganz - right heart catheterization

    Science.gov (United States)

    ... have: Abnormal pressures in the heart arteries Burns Congenital heart disease Heart failure Kidney disease Leaky heart valves (valvular ... 2011:chap 55. Read More Burns Cardiac tamponade Congenital heart disease Heart attack Heart failure - overview Pulmonary hypertension Restrictive ...

  5. Using Clinical Decision Support and Dashboard Technology to Improve Heart Team Efficiency and Accuracy in a Transcatheter Aortic Valve Implantation (TAVI) Program.

    Science.gov (United States)

    Clarke, Sarah; Wilson, Marisa L; Terhaar, Mary

    2016-01-01

    Heart Team meetings are becoming the model of care for patients undergoing transcatheter aortic valve implantations (TAVI) worldwide. While Heart Teams have potential to improve the quality of patient care, the volume of patient data processed during the meeting is large, variable, and comes from different sources. Thus, consolidation is difficult. Also, meetings impose substantial time constraints on the members and financial pressure on the institution. We describe a clinical decision support system (CDSS) designed to assist the experts in treatment selection decisions in the Heart Team. Development of the algorithms and visualization strategy required a multifaceted approach and end-user involvement. An innovative feature is its ability to utilize algorithms to consolidate data and provide clinically useful information to inform the treatment decision. The data are integrated using algorithms and rule-based alert systems to improve efficiency, accuracy, and usability. Future research should focus on determining if this CDSS improves patient selection and patient outcomes. PMID:27332170

  6. Strategies and outcomes of periprocedural bridging therapy with low-molecular-weight heparin in patients with mechanical heart valves.

    Science.gov (United States)

    Schulman, Jacqueline M; Majeed, Ammar; Mattsson, Eva; Schulman, Sam; Holmström, Margareta; Ågren, Anna

    2015-11-01

    Patients with mechanical heart valves (MHV) undergoing invasive procedures often receive periprocedural bridging with low-molecular-weight heparin (LMWH). The bridging strategies used in real-life and the predictors for bleeding and thrombosis are not well studied. We retrospectively assessed patients with MHV that underwent invasive procedures requiring vitamin K antagonist interruption and LMWH bridging. Thromboembolic and bleeding events occurring up to 30 days after the procedures were recorded. Predictors of major bleeding events (MBEs) were analyzed with logistic regression. We evaluated 547 patients with MHV who underwent 275 procedures during a 6.5-year period. Bridging with LMWH was used in 185 procedures in a total of 117 patients. Combined pre- and post-operative bridging was the most frequently employed (63 %). Doses of LMWH were prophylactic in 96 (52 %) of the procedures and therapeutic in 89 (48 %). The procedure-related bleeding risk was evaluated as high in 70 (38 %) and low in 115 (62 %) of the procedures. There was a trend to more frequent use of prophylactic doses (61 %) in high-risk surgery, and more therapeutic doses (53 %) in low-risk ones. There were 36 bleeding episodes, 21 (11 % of procedures) of which were classified as MBEs, but there were no thromboembolic events. Most MBEs (n = 14; 67 %) occurred in surgeries with high bleeding risk. In the multivariate analysis, the bleeding risk of the surgery itself was the only independent predictor for MBEs. For patients with MHV receiving perioperative bridging with LMWH, the major predictor for MBE is the bleeding risk of the surgery.

  7. Perioperative Anticoagulation in Patients with Mechanical Heart Valves Undergoing Elective Surgery: Results of a Survey Conducted among Korean Physicians

    Science.gov (United States)

    Kim, Sehyun; Lim, Chang Young; Lee, Jong Seok; Park, Seonyang; Garcia, David; Crowther, Mark A.; Ageno, Walter

    2005-01-01

    The optimal perioperative anticoagulation management in patients on warfarin therapy is poorly defined due to the lack of randomized trials. Because guidelines are heterogeneous, it was hypothesized that "treatment strategies are not uniform in clinical practice". Between February 2003 and May 2003, a questionnaire with 4 different clinical scenarios was distributed to physicians by e-mail, or direct contact was made by a survey monitor. Two scenarios described the cases of patients with a mechanical heart valve (MHV) in the mitral position, with additional risk factors for a systemic embolism; one undergoing major (scenario 1) and the other minor surgery (scenario 3). Two scenarios described patients with an aortic MHV; one undergoing major (scenario 2) and the other minor (scenario 4) surgery. Different preoperative and postoperative management options were offered. The treatment options for all scenarios were the same. Of the 90 questionnaires distributed, 52 (57.8%) were returned. Hospitalization for full-dose intravenous unfractionated heparin (IV UH) was the most commonly selected strategy in the preoperative phase for scenarios 1 (59%), 2 (42%) and 3 (44%). In scenario 4, 34% chose IV UH. Outpatient, full-dose, subcutaneous UH or low-molecular-weight heparin (LMWH) was the most selected option in the postoperative phase for all scenarios, with the exception of number 4 (52.9% in scenario 1, 34% in scenario 2, 32%, in scenario 3 and 28% in scenario 4). Even among expert clinicians, the management of perioperative anticoagulation is heterogeneous. In particular, the definition of risk categories and the optimal intensity of antithrombotic drugs need to be defined by well-designed prospective studies. PMID:15744807

  8. Strategies and outcomes of periprocedural bridging therapy with low-molecular-weight heparin in patients with mechanical heart valves.

    Science.gov (United States)

    Schulman, Jacqueline M; Majeed, Ammar; Mattsson, Eva; Schulman, Sam; Holmström, Margareta; Ågren, Anna

    2015-11-01

    Patients with mechanical heart valves (MHV) undergoing invasive procedures often receive periprocedural bridging with low-molecular-weight heparin (LMWH). The bridging strategies used in real-life and the predictors for bleeding and thrombosis are not well studied. We retrospectively assessed patients with MHV that underwent invasive procedures requiring vitamin K antagonist interruption and LMWH bridging. Thromboembolic and bleeding events occurring up to 30 days after the procedures were recorded. Predictors of major bleeding events (MBEs) were analyzed with logistic regression. We evaluated 547 patients with MHV who underwent 275 procedures during a 6.5-year period. Bridging with LMWH was used in 185 procedures in a total of 117 patients. Combined pre- and post-operative bridging was the most frequently employed (63 %). Doses of LMWH were prophylactic in 96 (52 %) of the procedures and therapeutic in 89 (48 %). The procedure-related bleeding risk was evaluated as high in 70 (38 %) and low in 115 (62 %) of the procedures. There was a trend to more frequent use of prophylactic doses (61 %) in high-risk surgery, and more therapeutic doses (53 %) in low-risk ones. There were 36 bleeding episodes, 21 (11 % of procedures) of which were classified as MBEs, but there were no thromboembolic events. Most MBEs (n = 14; 67 %) occurred in surgeries with high bleeding risk. In the multivariate analysis, the bleeding risk of the surgery itself was the only independent predictor for MBEs. For patients with MHV receiving perioperative bridging with LMWH, the major predictor for MBE is the bleeding risk of the surgery. PMID:25868460

  9. Hypoplastic left heart syndrome (image)

    Science.gov (United States)

    Hypoplastic left heart syndrome is a congenital heart condition that occurs during the development of the heart in the ... womb. During the heart's development, parts of the left side of the heart (mitral valve, left ventricle ...

  10. Clinical Analysis of Rheumatic Heart Valve Disease%风湿性心瓣膜病的临床观察分析

    Institute of Scientific and Technical Information of China (English)

    马大为

    2015-01-01

    ObjectiveTo study the analysis of rheumatic heart valve disease clinical manifestation, clinical treatment measures and effects.Methods Selected in our hospital in 2013 June to 2014 July were 24 cases of rheumatic valvular heart diseasepatients, the clinical data of the patients were retrospectively analyzed.ResultsRheumatic heart valve with coronary heart disease were 66.7% (16/24). Rheumatic heart valve with diabetes mellitus, hypertension was 20.8% (5/24), 12.5% (3/24). At the same time, a longer duration of patients and elderly patients with coronary heart disease and the proportion of larger; with a history of diabetes mellitus, hypertension patients with coronary heart disease probability is big; the old patients with hypertension and diabetic on has a strong role in promoting the occurrence of coronary heart disease.Conclusion Through the analysis and Study on rheumatic valvular disease, the main cause of coronary heart disease is the formation of rheumatic heart valve in patients with diabetes and hypertension disease causes, or merged with two kinds of diseases in a cause.%目的:研究分析风湿性心瓣膜病的临床表现、临床治疗措施和效果。方法选取我院2013年6月至2014年7月收治的24例风湿性心瓣膜病的患者,对患者的临床资料进行回顾性分析。结果风湿性心瓣膜合并冠心病的患者66.7%(16/24)。风湿性心瓣膜合并糖尿病、高血压为20.8%(5/24)、12.5%(3/24)。同时,病程较长的患者和高龄冠心病患者所占的比例较大;具有高血压、糖尿病史的患者患有冠心病的概率较大;高龄合并高血压以及糖尿病对冠心病的发生具有较强的促进作用。结论通过对风湿性心瓣膜疾病的分析和观察研究,冠心病主要形成的原因是风湿性心瓣膜患者合并糖尿病和高血压疾病导致,或者是合并两种疾病中的一种导致的。

  11. Effect of hinge gap width of a St. Jude medical bileaflet mechanical heart valve on blood damage potential--an in vitro micro particle image velocimetry study.

    Science.gov (United States)

    Jun, Brian H; Saikrishnan, Neelakantan; Arjunon, Sivakkumar; Yun, B Min; Yoganathan, Ajit P

    2014-09-01

    The hinge regions of the bileaflet mechanical heart valve (BMHV) can cause blood element damage due to nonphysiological shear stress levels and regions of flow stasis. Recently, a micro particle image velocimetry (μPIV) system was developed to study whole flow fields within BMHV hinge regions with enhanced spatial resolution under steady leakage flow conditions. However, global velocity maps under pulsatile conditions are still necessary to fully understand the blood damage potential of these valves. The current study hypothesized that the hinge gap width will affect flow fields in the hinge region. Accordingly, the blood damage potential of three St. Jude Medical (SJM) BMHVs with different hinge gap widths was investigated under pulsatile flow conditions, using a μPIV system. The results demonstrated that the hinge gap width had a significant influence during the leakage flow phase in terms of washout and shear stress characteristics. During the leakage flow, the largest hinge gap generated the highest Reynolds shear stress (RSS) magnitudes (~1000 N/m²) among the three valves at the ventricular side of the hinge. At this location, all three valves indicated viscous shear stresses (VSS) greater than 30 N/m². The smallest hinge gap exhibited the lowest level of shear stress values, but had the poorest washout flow characteristics among the three valves, demonstrating propensity for flow stasis and associated activated platelet accumulation potential. The results from this study indicate that the hinge is a critical component of the BMHV design, which needs to be optimized to find the appropriate balance between reduction in fluid shear stresses and enhanced washout during leakage flow, to ensure minimal thrombotic complications.

  12. Effect of hinge gap width of a St. Jude medical bileaflet mechanical heart valve on blood damage potential--an in vitro micro particle image velocimetry study.

    Science.gov (United States)

    Jun, Brian H; Saikrishnan, Neelakantan; Arjunon, Sivakkumar; Yun, B Min; Yoganathan, Ajit P

    2014-09-01

    The hinge regions of the bileaflet mechanical heart valve (BMHV) can cause blood element damage due to nonphysiological shear stress levels and regions of flow stasis. Recently, a micro particle image velocimetry (μPIV) system was developed to study whole flow fields within BMHV hinge regions with enhanced spatial resolution under steady leakage flow conditions. However, global velocity maps under pulsatile conditions are still necessary to fully understand the blood damage potential of these valves. The current study hypothesized that the hinge gap width will affect flow fields in the hinge region. Accordingly, the blood damage potential of three St. Jude Medical (SJM) BMHVs with different hinge gap widths was investigated under pulsatile flow conditions, using a μPIV system. The results demonstrated that the hinge gap width had a significant influence during the leakage flow phase in terms of washout and shear stress characteristics. During the leakage flow, the largest hinge gap generated the highest Reynolds shear stress (RSS) magnitudes (~1000 N/m²) among the three valves at the ventricular side of the hinge. At this location, all three valves indicated viscous shear stresses (VSS) greater than 30 N/m². The smallest hinge gap exhibited the lowest level of shear stress values, but had the poorest washout flow characteristics among the three valves, demonstrating propensity for flow stasis and associated activated platelet accumulation potential. The results from this study indicate that the hinge is a critical component of the BMHV design, which needs to be optimized to find the appropriate balance between reduction in fluid shear stresses and enhanced washout during leakage flow, to ensure minimal thrombotic complications. PMID:24976188

  13. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... heart valve which is made out of pyrolitic carbon, basically metal and plastic. Again, blood flows through ... heart surgery here, we actually insufflate, or instill carbon dioxide gas into the field, which we think ...

  14. Results of beating heart mitral valve surgery via the trans-septal approach Resultados da abordagem transeptal para a valva mitral com coração batendo

    Directory of Open Access Journals (Sweden)

    Tomas A Salerno

    2009-03-01

    Full Text Available OBJECTIVE: Mitral valve surgery can be performed through the trans-atrial or the trans-septal approach. Although the trans-atrial is the preferred method, the trans-septal approach has also been used recently and has a particular value in beating-heart mitral valve surgery. Herein we report our experience with beating-heart mitral valve surgery via trans-septal approach, and discuss its advantages and pitfalls. METHODS: Between 2000 and 2007, 214 consecutive patients were operated upon utilizing beating heart technique for mitral valve surgery. The operation was performed via transseptal approach with the aorta unclamped, the heart beating, with normal electrocardiogram and in sinus rhythm. RESULTS: Mean age was 56.03 ± 13.93 years (range: 19-86 years; median: 56 years. There were 131 (61.2% males and 83 (38.8% females. Of the prostheses used, 108 (50.5% were biological, and 39 (18.2% were mechanical. Mitral repairs were performed in 67 (31.3% patients. Mean hospital stay was 17.4 ± 20.0 days (range: 3-135 days; median: 11 days. Intra-aortic balloon pump (IABP utilization was required in 12 (5.6% of 214 patients. One-month mortality was 7.4%, and re-operation for bleeding was needed in 15 (7% patients. CONCLUSIONS: Beating-heart mitral valve surgery is an option for myocardial protection in patients undergoing mitral valve surgery. This technique is facilitated by the trans-septal approach due to reduced aortic insufficiency and improved visualization of the mitral apparatus.OBJETIVO: A cirurgia da valva mitral pode ser feita via transatrial ou transeptal. Embora a transatrial seja a preferida, a via transeptal tem sido utilizada mais recentemente e tido um grande valor nas operações com o coração batendo. Mostramos a nossa experiência na cirurgia da valva mitral via transeptal com coração batendo e discutimos seus benefícios e problemas. MÉTODOS: Entre 2000 e 2007, 214 pacientes consecutivos foram operados com o coração batendo. A

  15. A numerical analysis on the curved bileaflet Mechanical Heart Valve (MHV) : leaflet motion and blood flow in an elastic blood vessel

    International Nuclear Information System (INIS)

    In blood flow passing through the Mechanical Heart Valve (MHV) and elastic blood vessel, hemolysis and platelet activation causing thrombus formation can be seen owing to the shear stress in the blood. Also, fracture and deformation of leaflets can be observed depending on the shape and material properties of the leaflets which is opened and closed in a cycle. Hence, comprehensive study is needed on the hemodynamics which is associated with the motion of leaflet and elastic blood vessel in terms of fluid-structure interaction. In this paper, a numerical analysis has been performed for a three-dimensional pulsatile blood flow associated with the elastic blood vessel and curved bileaflet for multiple cycles in light of fluid-structure interaction. From this analysis fluttering phenomenon and rebound of the leaflet have been observed and recirculation and regurgitation have been found in the flow fields of the blood. Also, the pressure distribution and the radial displacement of the elastic blood vessel have been obtained. The motion of the leaflet and flow fields of the blood have shown similar tendency compared with the previous experiments carried out in other studies. The present study can contribute to the design methodology for the curved bileaflet mechanical heart valve. Furthermore, the proposed fluid-structure interaction method will be effectively used in various fields where the interaction between fluid flow and structure are involved

  16. Role of Pre-incision, Intravenous Prophylactic Amiodarone to Control Arrhythmias in Patients with Rheumatic Valvular Heart Disease undergoing Mitral Valve Replacement

    International Nuclear Information System (INIS)

    Objective: To evaluate the effect of intra-operative single intra venous dose of amiodarone on post operative cardiac arrhythmias in patients undergoing valvular heart surgery. Study Design: Randomized controlled trials. Place and Duration of surgery: This study was performed at Armed forces Institute of Cardiology Rawalpindi from Jan 01, 2011 to Dec 31, 2011. Patients and Methods: In this study 80 patients with rheumatic valvular heart disease and undergoing elective mitral valve replacement were randomly divided into two groups. Group I, n = 40 (Amiodarone group) was given single intravenous dose of amiodarone (5 mg/kg in 100 ml of saline over 30 min) before sternotomy incision. Group II, n = 40(control / placebo group) was given 100 ml of saline over 30 min. Result: In the amiodarone group, after removal of aortic cross clamp 75% patients had sinus rhythm compared to 47.5% in control group. p=0.045. Similarly 15% had AF, 5% JR and 5% VT/VF in amiodarone group in contrast to 32.5% with AF, 12.5% JR and 7.5% Vt/VF in control group. (p=0.045). Response to cardioversion was positive in 75% of the patients requiring shocks in amiodarone group as against 43.75% in the control group. (p=0.044). Conclusion: A single intravenous bolus dose of amiodarone is effective in decreasing the incidence of cardiac arrhythmias after mitral valve replacement in patients with rheumatic MVD. (author)

  17. Successful thrombolysis for prosthetic pulmonary valve obstruction.

    OpenAIRE

    Lopez, J. A.; Strickman, N E; Jin, B S; X. G. Li; Phan, B; Zeluff, B J; Wilansky, S

    1995-01-01

    Thrombosis is a serious complication of prosthetic heart valve operations. In recent years, systemic thrombolysis has emerged as a suitable alternative to surgery. Experience with thrombosis of pulmonary prosthetic valves is very limited. We report a case of successful administration of intravenous streptokinase for thrombosis of a St. Jude Medical prosthetic valve 3 weeks after pulmonary valve replacement.

  18. What Causes Heart Murmurs?

    Science.gov (United States)

    ... and get carried to the heart can sometimes infect the inner surface of the heart, including the heart valves. This rare but sometimes life-threatening infection is called infective endocarditis (EN-do-kar-DI-tis), or IE. IE ...

  19. Left heart catheterization

    Science.gov (United States)

    Catheterization - left heart ... then moved through the aortic valve into the left side of your heart. The pressure is measured ... coronary angiography) Take x-ray pictures of the left side of the heart (ventriculography)

  20. Evaluation of 17-mm St. Jude Medical Regent prosthetic aortic heart valves by rest and dobutamine stress echocardiography

    Directory of Open Access Journals (Sweden)

    Minardi Giovanni

    2006-09-01

    Full Text Available Abstract Background The prosthesis used for aortic valve replacement in patients with small aortic root can be too small in relation to body size, thus showing high transvalvular gradients at rest and/or under stress conditions. This study was carried out to evaluate rest and Dobutamine stress echocardiography (DSE hemodynamic response of 17-mm St. Jude Medical Regent (SJMR-17 mm in relatively aged patients at mean 24 months follow-up. Methods and results The study population consisted of 19 patients (2 men, 17 women, mean age 69.2 ± 7.3 years. All patients underwent rest Doppler echocardiography before and after surgery and basal and DSE at follow up (infused at rate of 5 micrg/Kg/min and increased by 5 microg/Kg/min at 5 min intervals up to 40 microg/Kg/min. The following parameters were evaluated at rest and/or under DSE: heart rate (HR, ejection fraction (EF, cardiac output (CO, peak and mean velocity and pressure gradients (MxV, MnV, MxPG, MnPG, effective orifice area (EOA, indexed EOA (EOAi, left ventricular mass (LVM, indexed LVM (LVMi, Velocity Time Integral at left ventricular outflow tract (VTI LVOT and transvalvular (Aortic VTI, Doppler velocity index (DVI. At rest MxPG and MnPG were 29.2 ± 7.1 and 16.6 ± 5.8mmHg, respectively; EOA and EOAi resulted 1.14 ± 0.3 cm2 and 0.76 ± 0.2 cm2/m2; DVI was normal (0.50 ± 0.1. At follow-up LVM and LVMi decreased significantly from pre-operative value of 258 ± 43g and 157.4 ± 27.7g/m2 to 191 ± 23.8g and 114.5 ± 10.6g/m2, respectively. DSE increased significantly HR, CO, EF, MxGP (up to 83.4 ± 2 1.9mmHg, MnPG (up to 43.2 ± 12.7mmHg. EOA, EOAi, DVI increased insignificantly (from baseline up to 1.2 ± 0.4 cm2, 0.75 ± 0.3cm2/m2 and 0.48 ± 0.1 respectively. Two patients developed significant intraventricular gradients. Conclusion These data show that SJMR 17-mm prostheses can be safely implanted in aortic position in relatively aged patients, offering a satisfactory hemodynamic

  1. A systematic method for using 3D echocardiography to evaluate tricuspid valve insufficiency in hypoplastic left heart syndrome

    Directory of Open Access Journals (Sweden)

    Christopher Robin Mart

    2014-01-01

    We have proposed a systematic method for evaluating and displaying the TV using 3DE which can provide significant insight into the mechanisms causing TVI in HLHS. This has the potential to improve both the surgical approach to repairing the valve and, ultimately, patient outcomes.

  2. [Modern mitral valve surgery].

    Science.gov (United States)

    Bothe, W; Beyersdorf, F

    2016-04-01

    At the beginning of the 20th century, Cutler and Levine performed the first successful surgical treatment of a stenotic mitral valve, which was the only treatable heart valve defect at that time. Mitral valve surgery has evolved significantly since then. The introduction of the heart-lung machine in 1954 not only reduced the surgical risk, but also allowed the treatment of different mitral valve pathologies. Nowadays, mitral valve insufficiency has become the most common underlying pathomechanism of mitral valve disease and can be classified into primary and secondary mitral insufficiency. Primary mitral valve insufficiency is mainly caused by alterations of the valve (leaflets and primary order chords) itself, whereas left ventricular dilatation leading to papillary muscle displacement and leaflet tethering via second order chords is the main underlying pathomechanism for secondary mitral valve regurgitation. Valve reconstruction using the "loop technique" plus annuloplasty is the surgical strategy of choice and normalizes life expectancy in patients with primary mitral regurgitation. In patients with secondary mitral regurgitation, implanting an annuloplasty is not superior to valve replacement and results in high rates of valve re-insufficiency (up to 30 % after 3 months) due to ongoing ventricular dilatation. In order to improve repair results in these patients, we add a novel subvalvular technique (ring-noose-string) to the annuloplasty that aims to prevent ongoing ventricular remodeling and re-insufficiency. In modern mitral surgery, a right lateral thoracotomy is the approach of choice with excellent repair and cosmetic results. PMID:26907868

  3. Pediatric heart surgery

    Science.gov (United States)

    Heart surgery - pediatric; Heart surgery for children; Acquired heart disease; Heart valve surgery - children ... There are many kinds of heart defects. Some are minor, and others are more serious. Defects can occur inside the heart or in the large blood vessels ...

  4. Micro particle image velocimetry measurements of steady diastolic leakage flow in the hinge of a St. Jude Medical® regent™ mechanical heart valve.

    Science.gov (United States)

    Jun, Brian H; Saikrishnan, Neelakantan; Yoganathan, Ajit P

    2014-03-01

    A number of clinical, in vitro and computational studies have shown the potential for thromboembolic complications in bileaflet mechanical heart valves (BMHV), primarily due to the complex and unsteady flows in the valve hinges. These studies have focused on quantitative and qualitative parameters such as velocity magnitude, turbulent shear stresses, vortex formation, and platelet activation to identify potential for blood damage. However, experimental characterization of the whole flow fields within the valve hinges has not yet been conducted. This information can be utilized to investigate instantaneous damage to blood elements and also to validate numerical studies focusing on the hinge's complex fluid dynamics. The objective of this study was therefore to develop a high-resolution imaging system to characterize the flow fields and global velocity maps in a BMHV hinge. In this study, the steady leakage hinge flow fields representing the diastolic phase during the cardiac cycle in a 23 mm St. Jude Medical regent BMHV in the aortic position were characterized using a two-dimensional micro particle image velocimetry system. Diastolic flow was simulated by imposing a static pressure head on the aortic side. Under these conditions, a reverse flow jet from the aortic to the ventricular side was observed with velocities in the range of 1.47-3.24 m/s, whereas low flow regions were observed on the ventricular side of the hinge with viscous shear stress magnitude up to 60 N/m². High velocities and viscous shearing may be associated with platelet activation and hemolysis, while low flow zones can cause thrombosis due to increased residence time in the hinge. Overall, this study provides a high spatial resolution experimental technique to map the fluid velocity in the BMHV hinge, which can be extended to investigate micron-scale flow domains in various prosthetic devices under different hemodynamic conditions.

  5. First report on intraoperative vector flow imaging of the heart among patients with healthy and diseased aortic valves

    DEFF Research Database (Denmark)

    Hansen, Kristoffer Lindskov; Møller-Sørensen, Hasse; Pedersen, Mads Møller;

    2014-01-01

    on (A) 3 patients with healthy aortic valve and (B) 3 patients with aortic valve stenosis. In group B, the systolic flow of the ascending aorta had higher velocities, was more aliased and chaotic. The jet narrowed to 44% of the lumen compared to 75% in group A and with a vector concentration, a measure......The vector velocity method Transverse Oscillation (TO) implemented on a conventional ultrasound (US) scanner (ProFocus, BK Medical, Herlev, Denmark) can provide real-time, angle-independent estimates of the cardiac blood flow. During cardiac surgery, epicardial US examination using TO was performed...... of flow complexity, of 0.41 compared to 0.87 in group A. The two groups had similar secondary flow of the ascending aorta with an average rotation frequency of 4.8 Hz. Simultaneous measurements were obtained with spectral Doppler (SD) and a thermodilution technique (TD). The mean difference in peak...

  6. Editorial to: Baseline MDCT findings after prosthetic heart valve implantation provide important complementary information to echocardiography for follow-up purposes by Sucha et al

    Energy Technology Data Exchange (ETDEWEB)

    Peeters, F.E.C.M. [Maastricht University Medical Center, Department of Cardiology, Maastricht (Netherlands); Kietselaer, B.L.J.H. [Maastricht University Medical Center, Department of Cardiology, Maastricht (Netherlands); Maastricht University Medical Center, Department of Radiology, Maastricht (Netherlands)

    2016-04-15

    Over the last years a growing number of prosthetic heart valve (PHV) implantation procedures have been performed in sequence with the aging of the population and improving surgical techniques. Currently, echocardiography is the most important tool in the follow-up and evaluation of complications associated with the PHV (pannus, thrombus, endocarditis). However, echocardiographic examination of PHV associated disease may be hampered by poor acoustic window or scatter artefacts caused by the PHV. PHV related disease such as endocarditis is related with a poor prognosis, especially when complications such as periannular abscess formation occurs. Early treatment of PHV associated disease improves prognosis. Therefore, an unmet clinical need for early detection of complications exists. In the evaluation of PHV (dys)function, multidetector-row computed tomography (MDCT) has shown to be of additive value. A necessity for MDCT to be implemented in daily practice is to be able to distinguish between normal and pathological features. (orig.)

  7. Evaluation of shrinkage temperature of bovine pericardium tissue for bioprosthetic heart valve application by differential scanning calorimetry and freeze-drying microscopy

    Directory of Open Access Journals (Sweden)

    Virgilio Tattini Jr

    2007-03-01

    Full Text Available Bovine pericardium bioprosthesis has become a commonly accepted device for heart valve replacement. Present practice relies on the measurement of shrinkage temperature, observed as a dramatic shortening of tissue length. Several reports in the last decade have utilized differential scanning calorimetry (DSC as an alternative method to determine the shrinkage temperature, which is accompanied by the absorption of heat, giving rise to an endothermic peak over the shrinkage temperature range of biological tissues. Usually, freeze-drying microscope is used to determine collapse temperature during the lyophilization of solutions. On this experiment we used this technique to study the shrinkage event. The aim of this work was to compare the results of shrinkage temperature obtained by DSC with the results obtained by freeze-drying microscopy. The results showed that both techniques provided excellent sensitivity and reproducibility, and gave information on the thermal shrinkage transition via the thermodynamical parameters inherent of each method.

  8. Editorial to: Baseline MDCT findings after prosthetic heart valve implantation provide important complementary information to echocardiography for follow-up purposes by Sucha et al

    International Nuclear Information System (INIS)

    Over the last years a growing number of prosthetic heart valve (PHV) implantation procedures have been performed in sequence with the aging of the population and improving surgical techniques. Currently, echocardiography is the most important tool in the follow-up and evaluation of complications associated with the PHV (pannus, thrombus, endocarditis). However, echocardiographic examination of PHV associated disease may be hampered by poor acoustic window or scatter artefacts caused by the PHV. PHV related disease such as endocarditis is related with a poor prognosis, especially when complications such as periannular abscess formation occurs. Early treatment of PHV associated disease improves prognosis. Therefore, an unmet clinical need for early detection of complications exists. In the evaluation of PHV (dys)function, multidetector-row computed tomography (MDCT) has shown to be of additive value. A necessity for MDCT to be implemented in daily practice is to be able to distinguish between normal and pathological features. (orig.)

  9. Evaluation of 17-mm St. Jude Medical Regent prosthetic aortic heart valves by rest and dobutamine stress echocardiography

    OpenAIRE

    Minardi Giovanni; Manzara Carla; Creazzo Vittorio; Maselli Daniele; Casali Giovanni; Pulignano Giovanni; Musumeci Francesco

    2006-01-01

    Abstract Background The prosthesis used for aortic valve replacement in patients with small aortic root can be too small in relation to body size, thus showing high transvalvular gradients at rest and/or under stress conditions. This study was carried out to evaluate rest and Dobutamine stress echocardiography (DSE) hemodynamic response of 17-mm St. Jude Medical Regent (SJMR-17 mm) in relatively aged patients at mean 24 months follow-up. Methods and results The study population consisted of 1...

  10. Cyclic fatigue and fracture in pyrolytic carbon-coated graphite mechanical heart-valve prostheses: role of small cracks in life prediction.

    Science.gov (United States)

    Dauskardt, R H; Ritchie, R O; Takemoto, J K; Brendzel, A M

    1994-07-01

    A fracture-mechanics based study has performed to characterize the fracture toughness and rates of cyclic fatigue-crack growth of incipient flaws in prosthetic heart-valve components made of pyrolytic carbon-coated graphite. Such data are required to predict the safe structural lifetime of mechanical heart-valve prostheses using damage-tolerant analysis. Unlike previous studies where fatigue-crack propagation data were obtained using through-thickness, long cracks (approximately 2-20 mm long), growing in conventional (e.g., compact-tension) samples, experiments were performed on physically small cracks (approximately 100-600 microns long), initiated on the surface of the pyrolytic-carbon coating to simulate reality. Small-crack toughness results were found to agree closely with those measured conventionally with long cracks. However, similar to well-known observations in metal fatigue, it was found that based on the usual computations of the applied (far-field) driving force in terms of the maximum stress intensity, Kmax, small fatigue cracks grew at rates that exceeded those of long cracks at the same applied stress intensity, and displayed a negative dependency on Kmax; moreover, they grew at applied stress intensities less than the fatigue threshold value, below which long cracks are presumed dormant. To resolve this apparent discrepancy, it is shown that long and small crack results can be normalized, provided growth rates are characterized in terms of the total (near-tip) stress intensity (incorporating, for example, the effect of residual stress); with this achieved, in principle, either form of data can be used for life prediction of implant devices. Inspection of the long and small crack results reveals extensive scatter inherent in both forms of growth-rate data for the pyrolytic-carbon material. PMID:8083247

  11. Pannus Formation Leads to Valve Malfunction in the Tricuspid Position 19 Years after Triple Valve Replacement.

    Science.gov (United States)

    Alskaf, Ebraham; McConkey, Hannah; Laskar, Nabila; Kardos, Attila

    2016-01-01

    The Medtronic ATS Open Pivot mechanical valve has been successfully used in heart valve surgery for more than two decades. We present the case of a patient who, 19 years following a tricuspid valve replacement with an ATS prosthesis as part of a triple valve operation following infective endocarditis, developed severe tricuspid regurgitation due to pannus formation. PMID:27355145

  12. The nordic aortic valve intervention (NOTION) trial comparing transcatheter versus surgical valve implantation

    DEFF Research Database (Denmark)

    Thyregod, Hans Gustav; Søndergaard, Lars; Ihlemann, Nikolaj;

    2013-01-01

    Degenerative aortic valve (AV) stenosis is the most prevalent heart valve disease in the western world. Surgical aortic valve replacement (SAVR) has until recently been the standard of treatment for patients with severe AV stenosis. Whether transcatheter aortic valve implantation (TAVI) can...

  13. Multidetector-row computed tomography for prosthetic heart valve dysfunction: is concomitant non-invasive coronary angiography possible before redo-surgery?

    Energy Technology Data Exchange (ETDEWEB)

    Tanis, Wilco [Haga Teaching Hospital, Department of Cardiology, The Hague (Netherlands); Haga Teaching Hospital, The Hague (Netherlands); Sucha, Dominika; Habets, Jesse [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Laufer, Ward; Chamuleau, Steven [University Medical Center Utrecht, Department of Cardiology, Utrecht (Netherlands); Herwerden, Lex.A. van [University Medical Center Utrecht, Department of Cardiothoracic Surgery, Utrecht (Netherlands); Symersky, Petr [Vrije Universiteit, Department of Cardiothoracic Surgery, Amsterdam (Netherlands); Budde, Ricardo P.J. [Erasmus Medical Center, Department of Radiology, Rotterdam (Netherlands)

    2015-06-01

    Retrospective ECG-gated multidetector-row computed tomography (MDCT) is increasingly used for the assessment of prosthetic heart valve (PHV) dysfunction, but is also hampered by PHV-related artefacts/cardiac arrhythmias. Furthermore, it is performed without nitroglycerine or heart rate correction. The purpose was to determine whether MDCT performed before potential redo-PHV surgery is feasible for concomitant coronary artery stenosis assessment and can replace invasive coronary angiography (CAG). PHV patients with CAG and MDCT were identified. Based on medical history, two groups were created: (I) patients with no known coronary artery disease (CAD), (II) patients with known CAD. All images were scored for the presence of significant (>50 %) stenosis. CAG was the reference test. Fifty-one patients were included. In group I (n = 38), MDCT accurately ruled out significant stenosis in 19/38 (50 %) patients, but could not replace CAG in the remaining 19/38 (50 %) patients due to non-diagnostic image quality (n = 16) or significant stenosis (n = 3) detection. In group II (n = 13), MDCT correctly found no patients without significant stenosis, requiring CAG imaging in all. MDCT assessed patency in 16/19 (84 %) grafts and detected a hostile anatomy in two. MDCT performed for PHV dysfunction assessment can replace CAG (100 % accurate) in approximately half of patients without previously known CAD. (orig.)

  14. Multidetector-row computed tomography for prosthetic heart valve dysfunction: is concomitant non-invasive coronary angiography possible before redo-surgery?

    International Nuclear Information System (INIS)

    Retrospective ECG-gated multidetector-row computed tomography (MDCT) is increasingly used for the assessment of prosthetic heart valve (PHV) dysfunction, but is also hampered by PHV-related artefacts/cardiac arrhythmias. Furthermore, it is performed without nitroglycerine or heart rate correction. The purpose was to determine whether MDCT performed before potential redo-PHV surgery is feasible for concomitant coronary artery stenosis assessment and can replace invasive coronary angiography (CAG). PHV patients with CAG and MDCT were identified. Based on medical history, two groups were created: (I) patients with no known coronary artery disease (CAD), (II) patients with known CAD. All images were scored for the presence of significant (>50 %) stenosis. CAG was the reference test. Fifty-one patients were included. In group I (n = 38), MDCT accurately ruled out significant stenosis in 19/38 (50 %) patients, but could not replace CAG in the remaining 19/38 (50 %) patients due to non-diagnostic image quality (n = 16) or significant stenosis (n = 3) detection. In group II (n = 13), MDCT correctly found no patients without significant stenosis, requiring CAG imaging in all. MDCT assessed patency in 16/19 (84 %) grafts and detected a hostile anatomy in two. MDCT performed for PHV dysfunction assessment can replace CAG (100 % accurate) in approximately half of patients without previously known CAD. (orig.)

  15. GIANT PROSTHETIC VALVE THROMBUS

    Directory of Open Access Journals (Sweden)

    Prashanth Kumar

    2015-04-01

    Full Text Available Mechanical prosthetic valves are predisposed to bleeding, thrombosis & thromboembolic complications. Overall incidence of thromboembolic complications is 1% per year who are on oral anticoagulants, whereas bleeding complications incidence is 0.5% to 6.6% per year. 1, 2 Minimization of Scylla of thromboembolic & Charybdis of bleeding complication needs a balancing act of optimal antithrombotic therapy. We are reporting a case of middle aged male patient with prosthetic mitral valve presenting in heart failure. Patient had discontinued anticoagulants, as he had subdural hematoma in the past. He presented to our institute with a giant prosthetic valve thrombus.

  16. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... a rare problem where the patient's own immune system will attack cardiac valve structures, causing them to ... it be heart, lung et cetera, the immune system recognizes those living issues as not being from ...

  17. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... North Carolina. My name is John Streitman and I'm a cardiothoracic surgeon here at the Heart ... the corrective surgery of aortic valve replacement. If I have aortic stenosis, are there any activities that ...

  18. Minimally Invasive Aortic Valve Replacement

    Medline Plus

    Full Text Available ... Dr. Jim Winkley, who's a cardiac anesthesiologist that works here with us. Before we begin, viewers need ... the valve itself has narrowed, that puts more work on the heart when a patient's at rest. ...

  19. Staphylococcus saprophyticus causing native valve endocarditis.

    Science.gov (United States)

    Garduño, Eugenio; Márquez, Irene; Beteta, Alicia; Said, Ibrahim; Blanco, Javier; Pineda, Tomás

    2005-01-01

    Coagulase negative staphylococci are a rare cause of native valve endocarditis. Staphylococcus saprophyticus is a coagulase-negative Staphylococcus infrequently reported as a human pathogen, and most of the cases reported are urinary tract infections. We describe a case of native valve endocarditis attributed to this organism. The patient needed valve replacement due to heart failure.

  20. Transcatheter, valve-in-valve transapical aortic and mitral valve implantation, in a high risk patient with aortic and mitral prosthetic valve stenoses

    Directory of Open Access Journals (Sweden)

    Harish Ramakrishna

    2015-01-01

    Full Text Available Transcatheter valve implantation continues to grow worldwide and has been used principally for the nonsurgical management of native aortic valvular disease-as a potentially less invasive method of valve replacement in high-risk and inoperable patients with severe aortic valve stenosis. Given the burden of valvular heart disease in the general population and the increasing numbers of patients who have had previous valve operations, we are now seeing a growing number of high-risk patients presenting with prosthetic valve stenosis, who are not potential surgical candidates. For this high-risk subset transcatheter valve delivery may be the only option. Here, we present an inoperable patient with severe, prosthetic valve aortic and mitral stenosis who was successfully treated with a trans catheter based approach, with a valve-in-valve implantation procedure of both aortic and mitral valves.

  1. BIOCHEMICAL AND MOLECULAR CHARACTERISTICS OF LISTERIA MONOCYTOGENES ISOLATES FROM A PROSTHETIC MITRAL HEART VALVE-BEARING PATIENT´S BLOOD CULTURES

    Directory of Open Access Journals (Sweden)

    Nilma Cintra Lea

    2013-09-01

    Full Text Available Background: In Brazil, listeriosis is not a notifiable disease; thus, the incidence of Brazilian cases remains unknown. Listeria monocytogenes is not always included in automated systems, and its detection depends on the high skill level of microbiology laboratory professionals. This paper describes the characteristics of L. monocytogenes isolates fortuitously obtained from an endocarditis case in Recife, PE, Brazil. Methods: Six bacterial isolates obtained from six blood cultures from a 28-year-old male bearing a prosthetic mitral heart valve were analyzed by PCR using primers specific of L. monocytogenes to confirm a presumptive identification, determine the serotype and presence of the virulence genes (inlA, inlB, inlC, inlJ, hly, plcA, actA, prfA in an attempt to determine the Listeria genotype by PCR-ribotyping. Results: The samples were identified as L. monocytogenes 4b. All investigated virulence genes were amplified by PCR, and the identity of the amplified segments was confirmed by sequencing. A deletion of 105 base pairs was detected in the actA gene. All of the samples generated the same PCR-ribotype pattern, clustered into a single ribotype, and were considered a single strain. Conclusion: L. monocytogenes infection should be considered in endocarditis differential diagnoses, especially among high-risk groups, due to its high pathogenicity and the environmental ubiquity.

  2. Biochemical and molecular characteristics of Listeria monocytogenes isolates from a prosthetic mitral heart valve-bearing patient´s blood cultures

    Directory of Open Access Journals (Sweden)

    Nilma Cintra Leal

    2013-09-01

    Full Text Available Background: In Brazil, listeriosis is not a notifiable disease; thus, the incidence of Brazilian cases remains unknown. Listeria monocytogenes is not always included in automated systems, and its detection depends on the high skill level of microbiology laboratory professionals. This paper describes the characteristics of L. monocytogenes isolates fortuitously obtained from an endocarditis case in Recife, PE, Brazil. Methods: Six bacterial isolates obtained from six blood cultures from a 28-year-old male bearing a prosthetic mitral heart valve were analyzed by PCR using primers specific of L. monocytogenes to confirm a presumptive identification, determine the serotype and presence of the virulence genes (inlA, inlB, inlC, inlJ, hly, plcA, actA, prfA in an attempt to determine the Listeria genotype by PCR-ribotyping. Results: The samples were identified as L. monocytogenes 4b. All investigated virulence genes were amplified by PCR, and the identity of the amplified segments was confirmed by sequencing. A deletion of 105 base pairs was detected in the actA gene. All of the samples generated the same PCR-ribotype pattern, clustered into a single ribotype, and were considered a single strain. Conclusion: L. monocytogenes infection should be considered in endocarditis differential diagnoses, especially among high-risk groups, due to its high pathogenicity and the environmental ubiquity.

  3. Work Status and Return to the Workforce after Coronary Artery Bypass Grafting and/or Heart Valve Surgery: A One-Year-Follow Up Study

    Directory of Open Access Journals (Sweden)

    Kirsten Fonager

    2014-01-01

    Full Text Available Background. Several characteristics appear to be important for estimating the likelihood of reentering the workforce after surgery. The aim of the present study was to describe work status in a two-year time period around the time of cardiac surgery and estimate the probability of returning to the workforce. Methods. We included 681 patients undergoing coronary artery bypass grafting and/or heart valve procedures from 2003 to 2007 in the North Denmark Region. We linked hospital data to data in the DREAM database which holds information of everyone receiving social benefits. Results. At the time of surgery 17.3% were allocated disability pension and 2.3% were allocated a permanent part-time benefit. Being unemployed one year before surgery reduced the likelihood of return to the workforce (RR=0.74 (0.60–0.92 whereas unemployment at the time of surgery had no impact on return to the workforce (RR=0.96 (0.78–1.18. Sickness absence before surgery reduced the likelihood of return to the workforce. Conclusion. This study found the work status before surgery to be associated with the likelihood of return to the workforce within one year after surgery. Before surgery one-fifth of the population either was allocated disability pension or received a permanent part-time benefit.

  4. Mitral valve prolapse - report of 3 cases

    International Nuclear Information System (INIS)

    Prolapse of mitral valve is characterized by its unique auscultatory, echocardiographic and angiographic findings and may be associated with various disease entities such as congenital heart disease, coronary heart disease and Marfan's syndrome etc. Authors report recent experience of 3 cases of prolapsed mitral valve, 2 cases associated with A.S.D. and 1 case with Marfan's syndrome.

  5. Reinforced chitosan-based heart valve scaffold and utility of bone marrow-derived mesenchymal stem cells for cardiovascular tissue engineering

    Science.gov (United States)

    Albanna, Mohammad Zaki

    Recent research has demonstrated a strong correlation between the differentiation profile of mesenchymal stem cells (MSCs) and scaffold stiffness. Chitosan is being widely studied for tissue engineering applications due to its biocompatibility and biodegradability. However, its use in load-bearing applications is limited due to moderate to low mechanical properties. In this study, we investigated the effectiveness of a fiber reinforcement method for enhancing the mechanical properties of chitosan scaffolds. Chitosan fibers were fabricated using a solution extrusion and neutralization method and incorporated into porous chitosan scaffolds. The effects of different fiber/scaffold mass ratios, fiber mechanical properties and fiber lengths on scaffold mechanical properties were studied. The results showed that incorporating fibers improved scaffold strength and stiffness in proportion to the fiber/scaffold mass ratio. A fiber-reinforced heart valve leaflet scaffold achieved strength values comparable to the radial values of human pulmonary and aortic valves. Additionally, the effects of shorter fibers (2 mm) were found to be up to 3-fold greater than longer fibers (10 mm). Despite this reduction in fiber mechanical properties caused by heparin crosslinking, the heparin-modified fibers still improved the mechanical properties of the reinforced scaffolds, but to a lesser extent than the unmodified fibers. The results demonstrate that chitosan fiber-reinforcement can be used to generate tissue-matching mechanical properties in porous chitosan scaffolds and that fiber length and mechanical properties are important parameters in defining the degree of mechanical improvement. We further studied various chemical and physical treatments to improve the mechanical properties of chitosan fibers. With combination of chemical and physical treatments, fiber stiffness improved 40fold compared to unmodified fibers. We also isolated ovine bone marrow-derived MSCs and evaluated their

  6. Comparison of SAPIEN 3 and SAPIEN XT transcatheter heart valve stent-frame expansion: evaluation using multi-slice computed tomography

    Science.gov (United States)

    Kazuno, Yoshio; Maeno, Yoshio; Kawamori, Hiroyuki; Takahashi, Nobuyuki; Abramowitz, Yigal; Babak, Hariri; Kashif, Mohammad; Chakravarty, Tarun; Nakamura, Mamoo; Cheng, Wen; Friedman, John; Berman, Daniel; Makkar, Raj R.; Jilaihawi, Hasan

    2016-01-01

    Aims Stent-frame morphology of the newer-generation, balloon-expandable transcatheter heart valve (THV), the SAPIEN 3 (S3), after transcatheter aortic valve implantation (TAVI) is unknown. We evaluated the THV stent-frame morphology post TAVI of the S3 using multi-slice computed tomography (MSCT) compared with the prior-generation THV, SAPIEN XT (S-XT). Methods and results A total of 94 consecutive participants of RESOLVE registry (NCT02318342) had MSCT after balloon-expandable TAVI (S3 = 39 and S-XT = 55). The morphology of the THV stent-frame was evaluated for expansion area and eccentricity at the THV-inflow, native annulus, mid-THV and THV-outflow levels. Mean %-expansion area for the S3 and the S-XT was 100.9 ± 5.7 and 96.1 ± 5.5%, respectively (P < 0.001). In the S3 group, the THV-inflow level had the largest value of %-expansion area, which decreased from THV-inflow to mid-THV level (105.2 ± 6.4 to 96.5 ± 5.9%, P < 0.001). However, in the S-XT group, %-expansion area increased from THV-inflow level to mid-THV level (93.2 ± 6.2 to 95.1 ± 6.1%, P = 0.0058). On nominal delivery balloon volume, the S3 in 88.5% of cases had overexpansion at the THV-inflow level. The observed degree of THV oversizing of the S3 was significantly lower than the S-XT (6.3 ± 8.6 vs. 11.8 ± 8.5%, P = 0.0027). Nonetheless, the incidence of post-procedural paravalvular aortic regurgitation (PVR) ≥ mild following the S3 TAVI was also significantly lower than the S-XT TAVI (17.9 vs. 43.6%, P = 0.014). Conclusion The newer-generation, balloon-expandable device, the S3, has a flared inflow morphology, whereas the prior-generation device, the S-XT, has relatively constrained inflow morphology post TAVI. This may contribute to a lesser degree of PVR with the S3. PMID:27002141

  7. Healthy Heart Quizzes

    Science.gov (United States)

    ... 24,2016 Cardiovascular Conditions • Conditions Home • Arrhythmia and Atrial Fibrillation • Cardiac Arrest • Cardiac Rehab • Cardiomyopathy • Cardiovascular Conditions of Childhood • Cholesterol • Congenital Heart Defects • Diabetes • Heart Attack • Heart Failure (HF) • Heart Valve Problems and Disease • High Blood ...

  8. Travel and Heart Disease

    Science.gov (United States)

    ... Privacy Policy Cardiovascular Conditions • Conditions Home • Arrhythmia and Atrial Fibrillation • Cardiac Arrest • Cardiac Rehab • Cardiomyopathy • Cardiovascular Conditions of Childhood • Cholesterol • Congenital Heart Defects • Diabetes • Heart Attack • Heart Failure (HF) • Heart Valve Problems and Disease • High Blood ...

  9. Preliminary Study of a New Heart Valve Prostheses Implanted with Minimally Invasive Techniques: Pulsatile-flow Testing in Vitro%一种新型介入瓣膜脉动流性能的初步研究

    Institute of Scientific and Technical Information of China (English)

    汤京龙; 王硕; 刘丽; 王健; 王春仁

    2013-01-01

    本文对一种国产新型介入瓣膜(HVPMIT)的体外脉动流性能进行了初步评价,并就该方法对HVPMIT的适用性进行了初步探索.试验中以国产HVPMIT为试验样品、进口的常规生物瓣为对照样品,根据ISO5840-2005和GB 12279-2008标准列出的方法,采用人工心脏瓣膜脉动流测试仪测定了试样的脉动流参数(包括平均跨瓣压差、返流百分比和有效开口面积).结果显示,在模拟心输出量为5 L/min时,HVPMIT的返流百分比高达13%,显著高于对照瓣,显示其发生了瓣周漏.进一步分析可以发现因为HVPMIT在植入体内时不需缝合,因此在HVPMIT支架外侧没有缝合环.当将HVPMIT夹持在试验仪器上时夹持垫片和HVPMIT支架间有明显缝隙,所以导致瓣周漏的发生.这说明,HVPMIT在外形、结构、在心脏上的固定方式、临床的手术方法等方面和传统的心脏瓣膜有明显的区别.必须根据其自身的特点,设计和建立适用的检测方法来科学客观地评价HVPMIT的性能.%The aim of this study was to investigate the pulsatile-flow performance in vitro of a new heart valve pros-theses implanted with minimally invasive techniques (HVPMIT). Three HVPMITs were tested valves and another three original biological heart valve prostheses acted as reference valves. The pulsatile-flow parameters (including mean pressure drop, regurgitant percentage of stroke volume, and effective orifice area) were tested in a pulse duplicator according to the methods listed in ISO5840-2005 and GB 12279-2008. The results demonstrated that the regurgitant percentage of stroke volume of tested valves was up to 13%. It was significantly higher than that of the reference valves. This result suggested that paravalvular leakage had occurred in the tested valves. It was found in the further analysis that because HVPMIT was not sewn into the heart tissue when the HVPMIT was implanted in vivo and there was not a sewing ring in the HVPMIT. when

  10. The Melody® valve and Ensemble® delivery system for transcatheter pulmonary valve replacement

    OpenAIRE

    McElhinney, Doff B.; Hennesen, Jill T

    2013-01-01

    The Melody® transcatheter pulmonary valve (TPV) is a percutaneous valve system designed for the treatment of obstruction and/or regurgitation of prosthetic conduits placed between the right ventricle and pulmonary arteries in patients with congenital heart disease. In 2000, Melody TPV became the first transcatheter valve implanted in a human; in 2006 it became the first transcatheter valve commercially available anywhere in the world; and in 2010 it was launched as the first commercially avai...

  11. Practice and effects of self-management education for 62 patients after heart valve reiplacement surgery%62例心脏瓣膜置换术后自我管理教育的实践

    Institute of Scientific and Technical Information of China (English)

    陈玉梅; 龚兴媛; 李有金; 陈永祥; 汤敏敏

    2011-01-01

    This paper summarizes the practice of self-management education for 62 patients after heart valve replacement surgery. Self-management education was implemented at three days after admission,one day before operation,one day before discharge and six months after discharge by providing patients with Handbook of self-management after heart valve replacement surgery,Diary of self-management after heart valve replacement surgery. This practice motivated the patients' and family members' positivity in participation of self-management,promoted the patients to form healthy self-management behaviors and habits,reduced postoperative complications and improved patients' quality of life.%对62例心脏瓣膜置换术后患者进行了自我管理教育.通过发放《心脏瓣膜置换术后自我管理相关知识册》《心脏瓣膜置换术后自我管理监测日志》,以及医护合作的方法,分别在患者入院后、手术前、出院前、出院后进行自我管理教育,调动了患者及家属积极参与及学习自我管理方法的主动性,促使患者形成并坚持良好的自我健康管理行为习惯,减少了并发症,提高了生活质量.

  12. Transcatheter Aortic Valve Replacement in Bicuspid Aortic Valve Disease

    DEFF Research Database (Denmark)

    Mylotte, Darren; Lefevre, Thierry; Søndergaard, Lars;

    2014-01-01

    BACKGROUND: Limited information exists describing the results of transcatheter aortic valve (TAV) replacement in patients with bicuspid aortic valve (BAV) disease (TAV-in-BAV). OBJECTIVES: This study sought to evaluate clinical outcomes of a large cohort of patients undergoing TAV-in-BAV. METHODS......: We retrospectively collected baseline characteristics, procedural data, and clinical follow-up findings from 12 centers in Europe and Canada that had performed TAV-in-BAV. RESULTS: A total of 139 patients underwent TAV-in-BAV with the balloon-expandable transcatheter heart valve (THV) (n = 48...

  13. Interventional treatment of common congenital heart diseases: the common view of Chinese medical experts. Part Four: Percutaneous balloon valvuloplasty for pulmonary and aortic valve stenosis

    International Nuclear Information System (INIS)

    Percutaneous balloon valvuloplasty has become the treatment of first choice for pulmonary valve stenosis. Congenital aortic valve stenosis can also be relieved by percutaneous balloon dilatation. Percutaneous valvuloplasty is indicated for patients with isolated pulmonary valve stenosis when the transvalvular peak systolic pressure gradient is over 40 mmHg and for patients with aortic valve stenosis when the pressure gradient exceeds 60 mmHg. A careful selection of patients, standardized procedure, individualized selection of the balloon type, size and length, and careful avoidance of any damage to chorda tendineae and to surrounding tissue are keys to achieving a successful procedure. Balloon valvuloplasty should be selectively performed in new-born and in infant since complications of the procedure are inversely related to age. (authors)

  14. Microstructure of Silicon-alloyed Pyrocarbon for Mechanical Heart Valves%人工心瓣含硅热解炭涂层的微观结构

    Institute of Scientific and Technical Information of China (English)

    张建辉; 孙海博; 王根明; 郭鹏海

    2011-01-01

    为了研究人工心瓣含硅热解炭涂层的微观结构,利用准稳态流化床反应装置制备出了含硅热解炭涂层,利用X射线衍射(XRD)、X射线能谱仪(EDS)、扫描电镜(SEM)、透射电镜(TEM)和偏光显微镜(PLM)对涂层微观结构进行了表征.结果表明,该涂层材料只有乱层结构热解炭和β型碳化硅两种物相,主要由直径为300 nm ~1μm的球形颗粒状碳结构组成,球形颗粒之间由片层状碳结构紧密相连,偶尔会形成闭合孔洞(直径约为0.1 ~1μm).涂层中硅元素宏观均匀分布且含量适中(6.48 wt%),直径约6~8nm的β型碳化硅晶粒无规则取向分布且存在微观尺度的集聚现象.含硅热解炭涂层的这些结构特征决定了其均匀致密、宏观各向同性的特性.%In order to study microstructure of silicon-alloyed pyrocarbon for mechanical heart valves, the silicon-alloyed pyrocarbon coating was prepared by a quasi-steady-state fluidized bed reactor. Microstructure of the coating was investigated by X-ray diffraction ( XRD ) , X-ray energy dispersive spectrometer ( EDS ) , scanning electron microscopy ( SEM ) , transmission electron microscopy ( TEM) and polarized light microscopy ( PLM). The results showed that the coating consisted of two phases, turbostratic pyrocarbon and (3 silicon carbide (β-SiC) , and was mainly composed of spherical particles that were from 300 nm to 1 μm in diameter. These spherical particles, between which there were occasionally pores (about 0. 1 - 1 μm in diameter) , were welded by laminar carbons. The silicon element whose content was moderate (6. 48 wt% ) distributed macro-unifonnly in the coating. The β-SiC grains about 6-8 nm in grain size distributed with random orientation and had some micro-scale agglomeration. These structural features of the silicon-alloyed pyrocarbon coating determined its uniform, dense and macroscopically isotropic properties.

  15. Has percutaneous aortic valve replacement taken center stage in the treatment of aortic valve disease?

    Science.gov (United States)

    Kumar, Gideon Praveen; Cui, Fangsen; Mathew, Lazar; Leo, Hwa Liang

    2013-01-01

    Modern biomedical advances have propelled percutaneous valve replacement into an effective and powerful therapy for many heart valve diseases, especially aortic valve stenosis. Experiences so far suggest that outcomes for new percutaneous valve replacement surgery compare favorably with that of traditional valve surgery in selected patients with severe symptomatic aortic stenosis. The inception of percutaneous aortic valve replacement (PAVR) began in 1992 when the potential for treating valve diseases was demonstrated through a modern technique of endoluminal deployment of a catheter-mounted crimped stented heart valve in an animal model. The first successful demonstration of such novel technique of surgical replacement of a heart valve was performed in 2002, when valve implantation in a patient with aortic stenosis was reported. Despite initial stumbles and a perception of being an uphill task, PAVR has emerged as one of the breakthroughs in surgical procedures. More than 1500 citations were found in PubMed, half of which were available after 2011. This is primarily because more than 50,000 procedures are being performed in more than 40 countries worldwide, with encouraging outcomes, and several stented valves have been launched in the market. This review provides a detailed analysis of the current state of the art of PAVR. Moreover, a competitive landscape of various devices available in the market and their design considerations, biomaterial selections, and overall hemodynamic performance are presented. PMID:24941416

  16. Mitral valve repair in acquired dextrocardia.

    Science.gov (United States)

    Elmistekawy, Elsayed; Chan, Vincent; Hynes, Mark; Mesana, Thierry

    2015-10-01

    Surgical correction of valvular heart disease in patients with dextrocardia is extremely rare. We report a surgical case of mitral valve repair in a patient with acquired dextrocardia. Successful mitral valve repair was performed through a right lateral thoracotomy. We describe our surgical strategy and summarize the literature.

  17. Mitral valve prolapse - report of 3 cases

    Energy Technology Data Exchange (ETDEWEB)

    Han, Moon Hee; Im, Chung Ki; Im, Dong Ran; Han, Man Chung; Lee, Young Woo; Seo, Jung Don [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1979-12-15

    Prolapse of mitral valve is characterized by its unique auscultatory, echocardiographic and angiographic findings and may be associated with various disease entities such as congenital heart disease, coronary heart disease and Marfan's syndrome etc. Authors report recent experience of 3 cases of prolapsed mitral valve, 2 cases associated with A.S.D. and 1 case with Marfan's syndrome.

  18. Perioperative anticoagulation for children with prosthetic mechanical valves

    OpenAIRE

    Grech, Victor E.; Rees, P.

    2000-01-01

    The insertion of a mechanical heart valve predisposes to thrombosis and embolism, and for this reason, individuals with mechanical valves who undergo dental/surgical procedures must take special precautions. In this article, we illustrate a protocol for anticoagulation during such procedures in individuals with mechanical valves.

  19. Heart Surgery Terms

    Science.gov (United States)

    ... Patients Choosing Wisely® Adult Cardiac Surgery What is Pediatric Heart Disease? What is Risk Adjustment? Valve Repair/Replacement Surgery Esophageal Surgery Lung/Thoracic Surgery Aneurysm Surgery Arrhythmia Surgery Other Types of Surgery Clinical ...

  20. All about Heart Rate (Pulse)

    Science.gov (United States)

    ... July 2015. Cardiovascular Conditions • Conditions Home • Arrhythmia and Atrial Fibrillation • Cardiac Arrest • Cardiac Rehab • Cardiomyopathy • Cardiovascular Conditions of Childhood • Cholesterol • Congenital Heart Defects • Diabetes • Heart Attack • Heart Failure (HF) • Heart Valve Problems and Disease • High Blood ...

  1. Clinical analysis of simultaneous operation of non-ischemic heart valve disease and coronary heart disease%非缺血性心脏瓣膜疾病合并冠心病同期手术治疗的临床分析

    Institute of Scientific and Technical Information of China (English)

    王保才; 程兆云; 葛振伟

    2015-01-01

    Objective To analyze the clinical characteristics and efficacy of simultoneous operation of non-ischemic heart valve disease and coronary heart disease earlier surgery.Methods In Henan provincial people' s hospital from June 2012 to June 2013,50 patients with non-ischemic heart valve diseose and coronary heart disease were selected as the research objects,all patients were taken to coronary artery bypass surgery,concomitant aortic,mitral and double valve replacement surgery.Results Only one case of postoperative cardiac arrest patients with multiple organ failure and death,and the cardiac function of remaining 49 patients were significantly improved;during postoperative follow-up,no late deaths occurred.Conclusions Induced myocardial ischemia in patients with coronary heart disease can significantly increased myocardial non-ischemic heart valve damage,if take timely measures to improve the function of myocardial ischemia and correct function of the heart valves,perfect protective effect on the heart muscle,to improve the quality of life of such patients,it have significant clinical implications.%目的 分析非缺血性心脏瓣膜疾病合并冠心病同期手术治疗的临床特点和疗效.方法 选取河南省人民医院2012年6月至2013年6月收治的50例非缺血性心脏瓣膜合并冠心病患者作为研究对象,所有患者均采取冠状动脉搭桥手术,同期行主动脉瓣、二尖瓣和双瓣膜置换术.结果 术后仅1例患者出现心脏骤停合并多器官功能衰竭且死亡,其余49例患者心脏功能均得到明显改善;术后进行随访,无晚期死亡病例出现.结论 冠心病患者引起的心肌缺血可以显著地加重非缺血性心脏瓣膜导致的心肌损害,若及时采取措施改善心肌缺血功能以及纠正心脏瓣膜的功能,完善对心肌的保护作用,对提高和改善该类病患的生活质量具有显著的临床意义.

  2. Transfemoral Valve-in-Valve Transcatheter Aortic Valve Implantation (TAVI) in a Patient With Previous Endovascular Aortic Repair (EVAR).

    Science.gov (United States)

    Ruparelia, Neil; Panoulas, Vasileios F; Frame, Angela; Nathan, Anthony W; Ariff, Ben; Jaffer, Usman; Sutaria, Nilesh; Chukwuemeka, Andrew; Mikhail, Ghada W; Malik, Iqbal S

    2016-07-01

    A 90-year-old man presented with increasing exertional breathlessness. He had previous implantation of a Perimount bioprosthetic aortic valve (Edwards Lifesciences) and coronary artery bypass graft surgery. Due to severe transvalvular bioprosthetic regurgitation with preserved left ventricular dimensions and ejection fraction, the heart team decided on valve-in- valve transcatheter aortic valve implantation via the transfemoral route in view of the patient's prohibitively high surgical and anesthetic risk. The patient had an uncomplicated recovery and was symptomatically much improved at 3-month follow-up. PMID:27342209

  3. Valve's Way

    Directory of Open Access Journals (Sweden)

    Phanish Puranam

    2015-06-01

    Full Text Available What can we learn from outliers? While statisticians rightly warn us against their non-representativeness, we believe it is also true that thinking carefully about what makes them atypical may improve our understanding of the typical case. This is the premise behind the Organization Zoo series. Valve Corporation (Valve is an unusual firm. It is a rare example of a firm that appears to operate without any formal hierarchy in its organization. What can we learn about the viability of authority hierarchies from Valve’s way of organizing? We wrote a brief account of Valve based on public information sources and asked several renowned organizational experts to comment on this unusual firm. We asked them to write a short commentary on what the Valve example means for organizational theorists and practitioners. Thankfully, they all accepted, and we are excited to present the results of their thinking in this first “exhibit” in the Organization Zoo.

  4. Aortic valve calcification and mild tricuspid regurgitation but no clinical heart disease after 8 years of dopamine agonist therapy for prolactinoma

    NARCIS (Netherlands)

    M. Kars; V. Delgado (Victoria); E.R. Holman (Eduard); R.A. Feelders (Richard); J.W.A. Smit (Jan); J.A. Romijn (Johannes); J.J. Bax (Jeroen); A.M. Pereira (Alberto)

    2008-01-01

    textabstractObjective: Treatment with ergot-derived dopamine agonists, pergolide, and cabergoline has been associated with an increased frequency of valvular heart disease in Parkinson's disease. The aim of the present study was to assess the prevalence of valvular heart disease in patients treated

  5. Flow field analysis of mechanical heart valves. Comparison of Starr-Edwards, Bjork-Shiley c-c, and St. Jude medical prostheses; Kikaiteki jinkoben no nagareba no kaiseki. Starr-Edwards, Bjork-Shiley c-c, oyobi St. Jude Medical ben no hikaku

    Energy Technology Data Exchange (ETDEWEB)

    Akutsu, T. [Kanto Gakuin University, Yokohama (Japan); Bishop, W. [Andronic Inc., Richmond, BC, (Canada); Modi, V. [University of British Columbia, Vancouver, BC (Canada)

    1996-03-25

    Three typical mechanical heart valves (Starr-Edwards, Bjork-Shiley c-c and St. Jude Medical) have been tested in the mitral position under pulsatile flow conditions. The test program included measurements of velocity and turbulent stresses at six downstream locations. The study was carried out using a sophisticated cardiac simulator in conjunction with a highly sensitive two-component laser Doppler anemometer system. The continuous monitoring of parametric time histories revealed useful details about the complex flow and also helped established location and time of the peak parameter values. Based on the experimental data, the following general conclusions can be drawn: (1) all 3 valve designs generated elevated turbulent stresses during acceleration and peak flow phases, presenting a possibility of thromboembolism, and perhaps, hemolysis; (2) valve configuration and valve orientation significantly affect the flow characteristics; (3) the Starr-Edwards valve with relatively a small opening area shows lower turbulent stresses; and (4) the bileaflet design of the St. Jude Medical valve is also associated with lower turbulent stresses, as compared to the Bjork-Shiley c-c valve. 7 refs., 14 figs.

  6. Analysis of the clinical effect of ischemic heart valve disease combined coronary heart disease with surgical operation in the same period%非缺血性心脏瓣膜疾病合并冠心病同期手术治疗的临床分析

    Institute of Scientific and Technical Information of China (English)

    郭盛

    2016-01-01

    Objective To study the clinical effect of ischemic heart valve disease combined coronary heart disease with surgical operation in the same period�Methods The clinical data of 31 cases patients of ischemic heart valve disease combined with coronary heart disease in Xinjiang Uygur Autonomous Region People′s Hospital from July 2013 to January 2015 were retrospective analyzed�According to the degree of cardiac function and symptoms,the patients toke the coronary artery bypass grafting treatment,combined with the actual operation of mitral valve replacement, mitral valve replacement, aortic valve replacement, double valve replacement at the same time�Postoperative follow⁃up for half year,the cardiac function of patients before and after operation were analyzed, the incidence of postoperative complications after the operation were record�Results All patients were treated by coronary artery bypass grafting, combined with the mitral valve replacement,mitral valve replacement, aortic valve replacement, double valve replacement for treatment during this period, the operations were success�There was statistically significant difference about cardiac functional grading before and after surgery ( P=0�000 )�There were 7 cases patients' left ventricular ejection ejection fraction( LVEF) was more than or equal to 40% of patients,24 cases patients'LVEF<40% before operation;21 cases patients'LVEF was more than or equal to 40%,8 cases patients'LVEF<40% after operation,the difference was statistical significance before and after the operation( P=0�000)�Only 2 patients were died because of low cardiac blood�Conclusion Non ischemic heart valve disease combined with coronary heart disease patients to take simultaneous surgical treatment, the difficulty of its operation has increased, but to strengthen myocardial protection during surgery can effectively enhance the clinical curative effect, reduce mortality, provide good protection for the survival of patients

  7. Transcatheter aortic valve replacement in elderly patients

    Institute of Scientific and Technical Information of China (English)

    Dimytri Siqueira; Alexandre Abizaid; Magaly Arrais J.; Eduardo Sousa

    2012-01-01

    Aortic stenosis is the most common native valve disease, affecting up to 5% of the elderly population. Surgical aortic valve replacement reduces symptoms and improves survival, and is the definitive therapy in patients with symptomatic severe aortic stenosis. However, despite the good results of classic surgery, risk is markedly increased in elderly patients with co-morbidities. Transcatheter aortic valve replacement (TAVR) allows implantation of a prosthetic heart valve within the diseased native aortic valve without the need for open heart surgery and cardiopulmonary bypass, offering a new therapeutic option to elderly patients considered at high surgical risk or with contraindications to surgery. To date, several multicenter registries and a randomized trial have confirmed the safety and efficacy of TAVR in those patients. In this chapter, we review the background and clinical applications of TAVR in elderly patients.

  8. 心脏瓣膜钙化与颈动脉内膜中层厚度的相关性研究%Relationship of Heart Valve Calcification and Carotid Intima Media Thickness

    Institute of Scientific and Technical Information of China (English)

    贾彦青; 党群; 姚民强; 李永健

    2012-01-01

    目的:研究心脏瓣膜钙化程度与颈动脉内膜中层厚度、斑块积分的相关性.方法:用经胸多普勒超声显像仪评估426例患者心脏瓣膜钙化情况,根据瓣膜钙化诊断标准将所有患者分为无钙化组、轻度钙化组、中度钙化组和重度钙化组.比较4组间的一般资料、病史、血压、血脂,同时测量4组患者颈动脉内膜中层厚度、软斑块积分、硬斑块积分及总斑块积分.结果:4组间的年龄、性别、体质量指数、吸烟情况、总胆固醇、三酰甘油、高密度脂蛋白胆固醇,低密度脂蛋白胆固醇差异无统计学意义;瓣膜钙化程度与冠心病患病率、收缩压、脉压、颈动脉内膜中层厚度、总斑块积分、硬斑块积分呈正相关(r.分别为0.546、0.628、0.512、0.802、0.628、0.544,均P<0.001),与舒张压、软斑块积分无相关性.结论:心脏瓣膜钙化程度可作为推测颈动脉内膜中层厚度、总斑块积分、硬斑块积分的一个重要指标.%Objective:To investigate the relationship between the degree of heart valve calcification and carotid intima media thickness and plaque integral. Methods: The valve calcification was assessed using transthoracic Doppler ultrasound imaging in 426 patients. All patients were divided into four groups according to the diagnostic criteria, including no calcification group, mild calcification group, moderate and severe calcification group. The general information, medical history, blood pressure, blood lipids were compared between four groups. The intima media thickness, suft plaque score, hard plaque score and the total plaque score of carotid artery were also measured in patients of four groups. Results: There were no significant differences in age, gender, body mass index, smoking status, total cholesterol, triglycerides, high density lipoprotein and low density lipoprotein between four groups. The degree of valve calcification was positively correlated with

  9. Hemorrhagic shock as a complication of anticoagulant therapy following the mitral valve replacement

    OpenAIRE

    Zah, Tajana; Ivančan, Višnja; TONKOVIĆ, DINKO; Krznarić, Željko; Klinar, Igor; Majerić Kogler, Višnja

    2007-01-01

    This report describes a case of the hemorrhagic shock in a patient on the anticoagulant therapy supplementing implanted mechanical prosthetic heart valve replacing the mitral valve. The association between hemorrhagic shock, mechanical prosthetic heart valve and anticoagulant therapy is briefly discussed.

  10. Comparison between Prothrombin Complex Concentrate (PCC) and Fresh Frozen Plasma (FFP) for the Urgent Reversal of Warfarin in Patients with Mechanical Heart Valves in a Tertiary Care Cardiac Center.

    Science.gov (United States)

    Fariborz Farsad, Bahram; Golpira, Reza; Najafi, Hamideh; Totonchi, Ziae; Salajegheh, Shirin; Bakhshandeh, Hooman; Hashemian, Farshad

    2015-01-01

    Fresh frozen plasma (FFP) and prothrombin complex concentrate (PCC) reverse oral anticoagulants such as Warfarin. We compared the standard dosage of FFP and PCC in terms of efficacy and safety for patients with mechanical heart valves undergoing interventional procedures while receiving Warfarin. Fifty patients were randomized (25 for each group) with mechanical heart valves [international normalized ratio (INR) >2.5]. FFP dosage was administered based on body weight (10-15 mL/Kg), while PCC dosage was administered based on both body weight and target INR. INR measurements were obtained at different time after PCC and FFP infusion. The mean ± SD of INR pre treatment was not significantly different between the PCC and FFP groups. However, over a 48-hour period following the administration of PCC and FFP, 76% of the patients in the PCC group and only 20% of the patients in the FFP group reached the INR target. Five (20%) patients in the PCC group received an additional dose of PCC, whereas 17 (68%) patients in the FFP group received a further dose of FFP (P=0.001). There was no significant difference between the two groups in Hb and Hct before and during a 48-hour period after PCC and FFP infusion. As regards safety monitoring and adverse drug reaction screening in the FFP group, the INR was high (INR > 2.5) in 86% of the patients. There was no report of hemorrhage in both groups. PCC reverses anticoagulation both effectively and safely while having the advantage of obviating the need to extra doses.

  11. The mechanical heart valve replacement surgery in the treatment of rheumatic heart disease in patients with atrial fibril ation psychological care%机械瓣膜替换术治疗风湿性心脏病合并心房颤动患者的心理护理

    Institute of Scientific and Technical Information of China (English)

    易红梅; 杜建文; 胡丽娟; 徐丽; 冯丽花

    2013-01-01

    目的:探讨使用机械瓣膜替换手术治疗风湿性心脏病合并房颤患者手术后给予心理护理的效果。方法以78例风湿性心脏病合并房颤患者为临床研究对象,患者均采用机械瓣膜替换手术,对照组给予常规护理,实验组给予围手术期心理护理,对比观察患者的护理效果。结果实验组患者围手术期心理焦虑程度较低,患者睡眠质量更好,出院后生活幸福感高,与对照组比较有显著差异,p<0.05。结论在机械瓣膜替换术治疗风湿性心脏病合并心房颤动患者护理工作中加强心理护理具有较好的效果。%Objective: To investigate the effect of psychological care given after surgical treatment of rheumatic heart disease in patients with atrial fibril ation surgery using a mechanical valve replacement. : 78 patients with rheumatic heart disease patients with atrial fibril ation clinical study, patients were treated with mechanical heart valve replacement surgery, the control group received conventional care, the experimental group were given perioperative psychological care, compared to observe the effect of the patient's care. Results: The experimental group patients perioperative the mental anxiety level is lower, the better quality of sleep in patients, the happiness of life after discharge, compared with the control group, a significant difference, p <0.05. Conclusion: The mechanical heart valve replacement surgery in the treatment of rheumatic heart disease in patients with atrial fibril ation care, strengthen psychological care with good results.

  12. Imaging of Cardiac Valves by Computed Tomography

    Directory of Open Access Journals (Sweden)

    Gudrun Feuchtner

    2013-01-01

    Full Text Available This paper describes “how to” examine cardiac valves with computed tomography, the normal, diseased valves, and prosthetic valves. A review of current scientific literature is provided. Firstly, technical basics, “how to” perform and optimize a multislice CT scan and “how to” interpret valves on CT images are outlined. Then, diagnostic imaging of the entire spectrum of specific valvular disease by CT, including prosthetic heart valves, is highlighted. The last part gives a guide “how to” use CT for planning of transcatheter aortic valve implantation (TAVI, an emerging effective treatment option for patients with severe aortic stenosis. A special focus is placed on clinical applications of cardiac CT in the context of valvular disease.

  13. [Valve-in-valve with Portico valve for a degenerative bioprosthetic surgical valve (Biocor)].

    Science.gov (United States)

    Latini, Roberto Adriano; Testa, Luca; Brambilla, Nedy; Tusa, Maurizio; Bedogni, Francesco

    2016-04-01

    In the last years, a general shift toward the use of surgical bioprosthetic aortic valves rather than mechanical valves with subsequent less use of anticoagulant therapy has been observed. However, bioprosthetic valves have limited durability. Reoperation, the current standard of care for these patients, carries a high surgical risk, especially because patients are elderly and with numerous comorbidities. Recently, transcatheter aortic valve replacement within a failed bioprosthetic valve (valve-in-valve procedure) has proven feasible. We here describe a case of valve-in-valve procedure with a Portico valve placed in a purely insufficient bioprosthetic valve (Biocor). PMID:27093211

  14. Mechanical aortic valve without anticoagulation for 33 years in a Yemeni man: a case report

    OpenAIRE

    Aman, Khadija

    2016-01-01

    Background Mechanical prosthetic heart valves have been used for many decades to replace damaged native valves. Guidelines mandate the use of anticoagulant therapy in patients with mechanical prosthetic valves of any type, irrespective of the position in the heart. The rationale for this is to prevent valve thrombosis and thromboembolic complications without increasing the risk of excess bleeding. We report a case involving a patient with a functioning aortic mechanical valve without any anti...

  15. Radiation-induced valvular heart disease.

    Science.gov (United States)

    Gujral, Dorothy M; Lloyd, Guy; Bhattacharyya, Sanjeev

    2016-02-15

    Radiation to the mediastinum is a key component of treatment with curative intent for a range of cancers including Hodgkin's lymphoma and breast cancer. Exposure to radiation is associated with a risk of radiation-induced heart valve damage characterised by valve fibrosis and calcification. There is a latent interval of 10-20 years between radiation exposure and development of clinically significant heart valve disease. Risk is related to radiation dose received, interval from exposure and use of concomitant chemotherapy. Long-term outlook and the risk of valve surgery are related to the effects of radiation on mediastinal structures including pulmonary fibrosis and pericardial constriction. Dose prediction models to predict the risk of heart valve disease in the future and newer radiation techniques to reduce the radiation dose to the heart are being developed. Surveillance strategies for this cohort of cancer survivors at risk of developing significant heart valve complications are required.

  16. 49 CFR 236.383 - Valve locks, valves, and valve magnets.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Valve locks, valves, and valve magnets. 236.383... Inspection and Tests § 236.383 Valve locks, valves, and valve magnets. Valve locks on valves of the non-cut-off type shall be tested at least once every three months, and valves and valve magnets shall...

  17. Piezoelectric valve

    Science.gov (United States)

    Petrenko, Serhiy Fedorovich

    2013-01-15

    A motorized valve has a housing having an inlet and an outlet to be connected to a pipeline, a saddle connected with the housing, a turn plug having a rod, the turn plug cooperating with the saddle, and a drive for turning the valve body and formed as a piezoelectric drive, the piezoelectric drive including a piezoelectric generator of radially directed standing acoustic waves, which is connected with the housing and is connectable with a pulse current source, and a rotor operatively connected with the piezoelectric generator and kinematically connected with the rod of the turn plug so as to turn the turn plug when the rotor is actuated by the piezoelectric generator.

  18. Valve's Way

    DEFF Research Database (Denmark)

    Foss, Nicolai Juul; Dobrajska, Magdalena

    2015-01-01

    Puranam and Håkonsson (2015) challenge us to ponder what we as organization design theorists make of Valve’s way (see also Jeppesen, 2008). We believe that Valve, in spite of its radical vision, does not represent a challenge to fundamental organization design theory and that it is questionable...... to what extent it represents a new blueprint for organization design, despite it being consistent with an “egalitarian Zeitgeist” (Puranam, 2014). In fact, managerial authority may be of increasing importance rather than the opposite (Guadalupe, Li, & Wulf, 2015). Thus, Valve is, and will remain...

  19. Coronary embolism in a patient with mitral valve prosthesis: successful management with tirofiban and half-dose tissue-type plasminogen activator

    Institute of Scientific and Technical Information of China (English)

    Yusuf Atmaca; Cagdas Ozdol; Cetin Erol

    2007-01-01

    @@ Coronary embolism has been considered as a rare cause of coronary occlusion.Prosthetic heart valve is an infrequent cause of this condition.The exact incidence of coronary embolization in patients with prosthetic heart valves is not well known.

  20. A Tandem Valve, a unique complication of TAVR

    Directory of Open Access Journals (Sweden)

    Srinivasan Sattiraju

    2016-02-01

    Full Text Available , MD1*,, MD1,, MD1,, MD2, MD2,, MD, PhD3 1. Division of Cardiology, Carle Heart and Vascular Institute, Carle Hospital, Urbana, IL 2. Cardiovascular Surgery, Carle Heart and Vascular Institute, Carle Hospital, Urbana, IL 3. Division of Cardiology, University of Minnesota Medical Center, Minneapolis, MN Received: 11-1-16, Reviewed: 22-1-16, Accepted: 26-1-16 Keywords: Transcatheter aortic valve replacement, TAVR, Valve embolisation DOI: ABSTRACT We report a unique complication of transcatheter aortic valve replacement (TAVR in which there is mechanical entrapment of two Edward Sapien valves. The tandem valve con guration created a high gradient across the valves stuck in tandem. The images and videos in this case capture ndings that underscore the complexity of interaction between two prosthetic valves. We believe this case serves a high teaching value for physicians taking care of patients with aortic stenosis managed with TAVR approach.

  1. Mitral valve disease—morphology and mechanisms

    Science.gov (United States)

    Levine, Robert A.; Hagége, Albert A.; Judge, Daniel P.; Padala, Muralidhar; Dal-Bianco, Jacob P.; Aikawa, Elena; Beaudoin, Jonathan; Bischoff, Joyce; Bouatia-Naji, Nabila; Bruneval, Patrick; Butcher, Jonathan T.; Carpentier, Alain; Chaput, Miguel; Chester, Adrian H.; Clusel, Catherine; Delling, Francesca N.; Dietz, Harry C.; Dina, Christian; Durst, Ronen; Fernandez-Friera, Leticia; Handschumacher, Mark D.; Jensen, Morten O.; Jeunemaitre, Xavier P.; Le Marec, Hervé; Le Tourneau, Thierry; Markwald, Roger R.; Mérot, Jean; Messas, Emmanuel; Milan, David P.; Neri, Tui; Norris, Russell A.; Peal, David; Perrocheau, Maelle; Probst, Vincent; Pucéat, Michael; Rosenthal, Nadia; Solis, Jorge; Schott, Jean-Jacques; Schwammenthal, Ehud; Slaugenhaupt, Susan A.; Song, Jae-Kwan; Yacoub, Magdi H.

    2016-01-01

    Mitral valve disease is a frequent cause of heart failure and death. Emerging evidence indicates that the mitral valve is not a passive structure, but—even in adult life—remains dynamic and accessible for treatment. This concept motivates efforts to reduce the clinical progression of mitral valve disease through early detection and modification of underlying mechanisms. Discoveries of genetic mutations causing mitral valve elongation and prolapse have revealed that growth factor signalling and cell migration pathways are regulated by structural molecules in ways that can be modified to limit progression from developmental defects to valve degeneration with clinical complications. Mitral valve enlargement can determine left ventricular outflow tract obstruction in hypertrophic cardiomyopathy, and might be stimulated by potentially modifiable biological valvular–ventricular interactions. Mitral valve plasticity also allows adaptive growth in response to ventricular remodelling. However, adverse cellular and mechanobiological processes create relative leaflet deficiency in the ischaemic setting, leading to mitral regurgitation with increased heart failure and mortality. Our approach, which bridges clinicians and basic scientists, enables the correlation of observed disease with cellular and molecular mechanisms, leading to the discovery of new opportunities for improving the natural history of mitral valve disease. PMID:26483167

  2. Mitral valve disease--morphology and mechanisms.

    Science.gov (United States)

    Levine, Robert A; Hagége, Albert A; Judge, Daniel P; Padala, Muralidhar; Dal-Bianco, Jacob P; Aikawa, Elena; Beaudoin, Jonathan; Bischoff, Joyce; Bouatia-Naji, Nabila; Bruneval, Patrick; Butcher, Jonathan T; Carpentier, Alain; Chaput, Miguel; Chester, Adrian H; Clusel, Catherine; Delling, Francesca N; Dietz, Harry C; Dina, Christian; Durst, Ronen; Fernandez-Friera, Leticia; Handschumacher, Mark D; Jensen, Morten O; Jeunemaitre, Xavier P; Le Marec, Hervé; Le Tourneau, Thierry; Markwald, Roger R; Mérot, Jean; Messas, Emmanuel; Milan, David P; Neri, Tui; Norris, Russell A; Peal, David; Perrocheau, Maelle; Probst, Vincent; Pucéat, Michael; Rosenthal, Nadia; Solis, Jorge; Schott, Jean-Jacques; Schwammenthal, Ehud; Slaugenhaupt, Susan A; Song, Jae-Kwan; Yacoub, Magdi H

    2015-12-01

    Mitral valve disease is a frequent cause of heart failure and death. Emerging evidence indicates that the mitral valve is not a passive structure, but--even in adult life--remains dynamic and accessible for treatment. This concept motivates efforts to reduce the clinical progression of mitral valve disease through early detection and modification of underlying mechanisms. Discoveries of genetic mutations causing mitral valve elongation and prolapse have revealed that growth factor signalling and cell migration pathways are regulated by structural molecules in ways that can be modified to limit progression from developmental defects to valve degeneration with clinical complications. Mitral valve enlargement can determine left ventricular outflow tract obstruction in hypertrophic cardiomyopathy, and might be stimulated by potentially modifiable biological valvular-ventricular interactions. Mitral valve plasticity also allows adaptive growth in response to ventricular remodelling. However, adverse cellular and mechanobiological processes create relative leaflet deficiency in the ischaemic setting, leading to mitral regurgitation with increased heart failure and mortality. Our approach, which bridges clinicians and basic scientists, enables the correlation of observed disease with cellular and molecular mechanisms, leading to the discovery of new opportunities for improving the natural history of mitral valve disease.

  3. Drug-related cardiac valve disease.

    Science.gov (United States)

    2013-12-01

    Cardiac valve disease can involve one or more of the four heart valves. Chronic valve damage may remain asymptomatic for long periods but ultimately leads to haemodynamic overload of the heart. The most common causes of valve disease are rheumatic diseases, infections, chronic renal failure, malformations, and genetic diseases. Valve disease is often attributed to degeneration with no known cause.The frequency of drug-related valve disease has long been underestimated. Most implicated drugs have serotonergic properties, such as fenfluramine-derived amphetamines, including benfluorex. Rye ergot derivatives can also be implicated: these include dopamine agonists (bromocriptine, lisuride, pergolide and cabergoline), migraine treatments (methysergide, ergotamine and dihydroergotamine), and drugs used for cognitive and neurosensory deficits (nicergoline, dihydroergocryptine, etc.). "Ecstasy", an amphetamine, is sometimes also involved. The risk increases after a few months of exposure. Drug withdrawal is sometimes followed by an improvement. Patients exposed to a drug known to cause valve damage should be informed of the risk and receive long-term monitoring to detect these lesions before they become irreversible. The possible role of a drug should always be considered when cardiac valve disease is diagnosed, in order to facilitate active research and to avoid exposing other patients to this risk. PMID:24600729

  4. Keeping Your Heart Healthy After Treatment for Childhood Cancer

    Science.gov (United States)

    ... ventricles) within the heart that work together to pump blood. Valves direct the flow of blood through the ... arrhythmia), or an inability of the heart to pump blood properly (congestive heart failure). Which types of cancer ...

  5. Excess flow shutoff valve

    Energy Technology Data Exchange (ETDEWEB)

    Kiffer, Micah S.; Tentarelli, Stephen Clyde

    2016-02-09

    Excess flow shutoff valve comprising a valve body, a valve plug, a partition, and an activation component where the valve plug, the partition, and activation component are disposed within the valve body. A suitable flow restriction is provided to create a pressure difference between the upstream end of the valve plug and the downstream end of the valve plug when fluid flows through the valve body. The pressure difference exceeds a target pressure difference needed to activate the activation component when fluid flow through the valve body is higher than a desired rate, and thereby closes the valve.

  6. Heart Failure in Children and Adolescents

    Science.gov (United States)

    ... of the heart. It's then pumped into the aorta, which distributes it throughout the body to provide ... due to effects of smoking, high blood pressure, diabetes, coronary artery disease and bad heart valves. It ...

  7. Vacuum Valve

    CERN Multimedia

    1974-01-01

    This valve was used in the Intersecting Storage Rings (ISR) to protect against the shock waves that would be caused if air were to enter the vacuum tube. Some of the ISR chambers were very fragile, with very thin walls - a design required by physicists on the lookout for new particles.

  8. Review of Ten Years' Use of St. Jude Medical Prosthetic Valve Replacement and Postoperative Management at Niigata University Hospital

    OpenAIRE

    Hayashi, Jun-Ichi; Oguma, Fumiaki; Tsuchida, Sho-ichi; Fujita, Yasuo; Nakazawa, Satoshi; Miyamura, Haruo; Eguchi, Shoji

    1993-01-01

    A ten-year period of using St. Jude Medical (SJM) prosthetic heart valves at Niigata University Hospital was reviewed. Between December 1979 and August 1990, 261 patients, 118 males and 143 females, ages ranging 6-75 years, underwent SJM prosthetic valve replacement. Aortic valve replacement was performed in 72 patients, mitral valve replacement in 140 patients, combined aortic and mitral valve replacement in 37 patients, and miscellaneous valve replacement in 12 patients. The actuarial survi...

  9. Community - based Rehabilitation and Health Management in Patients with Mechanical Heart Valve Replacement%人工机械瓣膜置换术后患者的社区康复管理

    Institute of Scientific and Technical Information of China (English)

    胡丕; 余舜; 胡知朋

    2014-01-01

    Objective To explore the significance of community - based rehabilitation and health management in pre-venting and treating long - term complications after mechanical heart valve replacement, Methods During February 2001 to July 2012,83 prosthetic valve implanted patients were included and their health archives were established, All the patients included were given health education,periodic physical examination and complication diagnosis and treatment, Results Follow - up to May 1st,2013,of the 83 patients,no one died of valve disease or complications but three patients(3, 6% )died of lung canc-er,trauma and gastric cancer respectively;79 patients(95, 2% )reached the presupposed anticoagulation standard;8 patients (9, 6% )experienced hemorrhagic tendency and one patient were diagnosed as encephalorrhagia by using MRI;3 patients (3, 6% )were diagnosed as cardiac function NAHY grade Ⅱ and their heart failure was induced by pneumonia,anemia and over-work respectively,but no cardiac shock occurred;3 patients(3, 6% )were diagnosed as atrial fibrillation for the first time and 2 patients(2, 4% )experienced worsened atrial fibrillation that obviously influenced haemodynamics;One patient(1, 2% )ex-perienced ventricular arrhythmias following the infective endocarditis, Conclusion Community - based rehabilitation and health management is of great significance for preventing and treating the long - term complications after prosthetic valve replacement.%目的:探讨社区康复管理在防治人工机械瓣膜置换术后患者远期并发症中的意义。方法2001年2月—2012年7月,共计83例金属瓣膜置换患者在杨柳湾镇中心卫生院建立健康档案,接受系统的健康宣教、定期体检、并发症判断和处理。结果随访至2013-05-01,本组患者死亡3例(3,6%),死亡原因为肺癌、创伤、胃癌各1例,无一例因心脏瓣膜病或相关并发症死亡;总抗凝达标人数79例(95,2%);出血倾向8例(9,6%

  10. Aortic Valve Sparing in Different Aortic Valve and Aortic Root Conditions.

    Science.gov (United States)

    David, Tirone E

    2016-08-01

    The development of aortic valve-sparing operations (reimplantation of the aortic valve and remodeling of the aortic root) expanded the surgical armamentarium for treating patients with aortic root dilation caused by a variety of disorders. Young adults with aortic root aneurysms associated with genetic syndromes are ideal candidates for reimplantation of the aortic valve, and the long-term results have been excellent. Incompetent bicuspid aortic valves with dilated aortic annuli are also satisfactorily treated with the same type of operation. Older patients with ascending aortic aneurysm and aortic insufficiency secondary to dilated sinotubular junction and a normal aortic annulus can be treated with remodeling of the aortic root or with reimplantation of the aortic valve. The first procedure is simpler, and both procedures are likely equally effective. As with any heart valve-preserving procedure, patient selection and surgical expertise are keys to successful and durable repairs. PMID:27491910

  11. Transcatheter Versus Surgical Aortic Valve Replacement in Patients With Severe Aortic Valve Stenosis

    DEFF Research Database (Denmark)

    Thyregod, Hans Gustav; Steinbrüchel, Daniel Andreas; Ihlemann, Nikolaj;

    2015-01-01

    BACKGROUND: Transcatheter aortic valve replacement (TAVR) is an option in certain high-risk surgical patients with severe aortic valve stenosis. It is unknown whether TAVR can be safely introduced to lower-risk patients. OBJECTIVES: The NOTION (Nordic Aortic Valve Intervention Trial) randomized...... clinical trial compared TAVR with surgical aortic valve replacement (SAVR) in an all-comers patient cohort. METHODS: Patients ≥ 70 years old with severe aortic valve stenosis and no significant coronary artery disease were randomized 1:1 to TAVR using a self-expanding bioprosthesis versus SAVR. The primary...... conduction abnormalities requiring pacemaker implantation, larger improvement in effective orifice area, more total aortic valve regurgitation, and higher New York Heart Association functional class at 1 year. SAVR-treated patients had more major or life-threatening bleeding, cardiogenic shock, acute kidney...

  12. 心脏机械瓣膜置换术后华法林低强度抗凝疗效观察%Efficacy of warfarin low intense anticoagulation after heart valve replacement

    Institute of Scientific and Technical Information of China (English)

    刘状; 葛圣林; 张成鑫

    2014-01-01

    目的:探讨安徽地区汉族人心脏机械瓣膜置换术后华法林低强度抗凝应用于患者的安全性,为瓣膜置换术后患者给予最佳的华法林抗凝剂量及最佳的INR控制标准提供参考。方法对安徽医科大学第一附属医院2010年1月至2013年1月期间509例安徽省地区汉族人群人工机械瓣膜置换术后的患者给予华法林低强度抗凝治疗。随访期间,记录其PT、INR值及华法林剂量。统计出血及血栓、栓塞等不良事件的发生。结果失访及数据不完整的有40例,数据较完整的有469例,随访1~37个月,平均(18.13±6.02)月,总随访1960.8人年。男211例,女258例,平均年龄(40.52±13.38)岁,其中行MVR 268例,AVR 115例,DVR 86例。所换瓣膜均为双叶机械瓣膜,其中153枚St.Jude Regent瓣膜,291枚CarboMedics瓣膜,111枚国产GKS瓣膜。结果平均INR为2.11±0.56,平均华法林剂量为(3.124±2.4)mg。共有47例抗凝相关并发症,其中出血事件37例(发生率为1.89%pt-y),血栓、栓塞事件有10例(发生率为0.51%pt-y)。另外,5例死亡,与抗凝相关有3例。术前患者共有316例合并房颤,43例合并左房血栓。结论安徽省人群瓣膜置换术后患者INR控制在1.8~2.2是合适的,可以有效控制血栓、栓塞及出血等并发症的发生。合并房颤患者及行DVR的患者的抗凝相关并发症发生率较高,此类患者应加大复查频次,及时调整华法林剂量。%Objective To evaluate the safety of warfarin low intensity anticoagulation after mechanical heart valve replacement in Anhui Han population ,and to identify optimum international normalized ratio ( INR) levels and required warfarin doses and anticoagulation-re-lated complications in patients following mechanical heart valve replacement .Methods We studied 509 patients who underwent me-chanical valve replacement with low intensity

  13. 机械心脏瓣膜术后患者自我管理行为的研究%Research for self- management action of patient suffered from mechanical heart valve post-operation

    Institute of Scientific and Technical Information of China (English)

    李飞霞; 袁述兰; 梁克

    2011-01-01

    目的 探讨机械心脏瓣膜术后患者行为的自我管理.方法 将168例机械心脏瓣膜术后患者随机分为干预组86例和对照组82例.干预组患者在常规药物治疗的同时给予有针对性的自我管理教育,而对照组患者在常规药物治疗的同时则行常规健康教育,分别于治疗护理1年后采用"自我管理行为量表"对两组患者进行测定,评估两组患者的自我管理行为,并应用中文版SF-36量表对两组患者进行评价,比较两组患者的生活质量(QOL).结果 治疗护理1年后,干预组患者的自我管理行为量表及SF-36量表的各项评分均明显高于对照组,两组比较差异均有统计学意义(P<0.01).结论 自我管理教育可帮助患者建立良好的健康行为模式,能提高患者自我管理疾病的能力,减少并发症的发生,从而促进康复,达到提高机械心脏瓣膜术后患者生活质量的目的.%Objective To explore the self-management action of patient suffered from mechanical heart valve post-operation. Methods 168cases of the patients suffered from the mechanical heart valve post-operation were separately divided into 86 cases as the interference group and 82 cases as control group at random. The interference group was given for the normal medical treatment and also objective self-management education but the control group used normal medical treatment and also health education. Two groups of the patients were tested by "Self-Management Action Measurement Form" separately to asseSS the self-management action and also were assessed by Chinese version of SF-36 Measurement Form for the assessment of two groups of the patients for the comparison of the patients of two groups in living quality(QOL) one year after treatment and nursing. Results The various items of assessments of interference group were higher than the comparison group in self-management action measurement form SF-36 Measurement Form with the difference of statistics meaning

  14. Transcatheter mitral valve implantation via transapical approach

    DEFF Research Database (Denmark)

    Sondergaard, Lars; Brooks, Matthew; Ihlemann, Nikolaj;

    2015-01-01

    OBJECTIVES: As many as 50% of patients with severe symptomatic mitral valve regurgitation are denied surgical valve replacement or repair due to high operative risk. We describe an early series of cases of transcatheter implantation with a CardiAQ™ mitral valve via a transapical approach. METHODS......: Three consecutive patients with an Society of Thoracic Surgeons (STS) mortality score of >22% were selected for transcatheter mitral valve implantation (TMVI) on compassionate grounds. All patients were elderly, had severe mitral regurgitation (MR), were in Class IV heart failure and deemed unsuitable...... bypass surgery (n = 2), severe pulmonary hypertension (n = 1) and moderate to severe chronic renal failure (n = 3). A CardiAQ mitral valve was implanted using fluoroscopy and transoesophageal (TEE) guidance via a standard transapical approach. RESULTS: Accurate prosthesis positioning and deployment...

  15. Aortic valve bypass

    DEFF Research Database (Denmark)

    Lund, Jens T; Jensen, Maiken Brit; Arendrup, Henrik;

    2013-01-01

    In aortic valve bypass (AVB) a valve-containing conduit is connecting the apex of the left ventricle to the descending aorta. Candidates are patients with symptomatic aortic valve stenosis rejected for conventional aortic valve replacement (AVR) or transcatheter aortic valve implantation (TAVI...

  16. Preliminary MRI study on hemodynamics after prosthetic cardiac valve implantation

    International Nuclear Information System (INIS)

    Objective: To assess the function of prosthetic valve by magnetic resonance imaging (MRI), and to measure the blood velocity downstream of prosthetic valve and three-dimensional surface profiles so as to provide the original materials for appearance and development of thrombi-embolic complications in the long time follow-up. Methods: Twenty-seven cases with prosthetic aortic valve were examined and the blood velocity was measured by using MRI. The diseased heart valves were replaced with two prosthetic valves in 20 cases, and replaced with single prosthetic valve in 7 cases. The axial velocity components were measured at three positions near the valve including half, one, and two diameter downstream in the ascending aorta. Two and three-dimensional surface profile reconstruction were analyzed by using flow analysis software and Matlab 6.5 software. Results: In 16 cases with prosthetic aortic valve replacement with two leaflets prosthetic valves, the velocity profiles downstream of the valve prosthetic reflecting the valve design was nearly three velocity, jets of the two major orifices and the central slit between the two leaflets. In 4 cases with prosthetic aortic valve replace with Sorin two leaflets prosthetic valve, the velocity profiles downstream was nearly two velocity jets of the two major orifices. In 20 cases replaced with two leaflets prosthetic valves, blood velocity profiles were skewed with highest velocities. Seven cases with single leaflet showed single velocity jets of the major orifices at peak systole. Retrograde velocities occurred in part of the lateral orifice regions in 26 cases. Three-dimensional surface profiles downstream of the prosthetic aortic valve reflected the valve design. The blood velocity profiles with prosthetic aortic valve in the one diameter downstream in the ascending aorta clearly showed the valve design. Conclusion: MRI is a non-invasive, direct, and in-vivo method of choice to assess the valvular function and is the

  17. Three-dimensional echocardiography in valve disease

    Science.gov (United States)

    COLOMBO, CHIARA; TAMBORINI, GLORIA; PEPI, MAURO; ALIMENTO, MARINA; FIORENTINI, CESARE

    2007-01-01

    This review covers the role of three-dimensional (3D) echocardiography in the diagnosis of heart valve disease. Several factors have contributed to the evolution of this technique, which is currently a simple and routine method: rapid evolution in probe and computer technologies, demonstration that 3D data sets allowed more complete and accurate evaluation of cardiac structures, emerging clinical experience indicating the strong potential particularly in valve diseases, volume and function of the two ventricle measurements and several other fields. This report will review current and future applications of 3D echocardiography in mitral, aortic and tricuspid valve diseases underlying both qualitative (morphologic) and quantitative advantages of this technique. PMID:21977273

  18. Types of Congenital Heart Defects

    Science.gov (United States)

    ... Thus, the heart has to work harder to pump blood through the valve. Atresia (ah-TRE-ze-AH). ... right ventricle can get very overworked trying to pump blood to the pulmonary artery. These infants may have ...

  19. Protect Your Heart in the Heat

    Science.gov (United States)

    ... For Seniors Cardiovascular Conditions • Conditions Home • Arrhythmia and Atrial Fibrillation • Cardiac Arrest • Cardiac Rehab • Cardiomyopathy • Cardiovascular Conditions of Childhood • Cholesterol • Congenital Heart Defects • Diabetes • Heart Attack • Heart Failure (HF) • Heart Valve Problems and Disease • High Blood ...

  20. Automatic shutoff valve

    Science.gov (United States)

    Hawkins, S. F.; Overbey, C. W.

    1980-01-01

    Cellulose-sponge disk absorbs incoming water and expands with enough force to shut valve. When water recedes, valve opens by squeezing sponge dry to its original size. This direct mechanical action is considered more reliable than solenoid valve.

  1. Substituição valvar mitral com papilopexia cruzada e constrição anular em pacientes com insuficiência cardíaca Mitral valve replacement with crossed papillopexy and annular constriction in heart failure patients

    Directory of Open Access Journals (Sweden)

    Ricardo Adala Benfatti

    2008-09-01

    Full Text Available OBJETIVO: Analisar os resultados em curto e médio prazo de pacientes portadores de insuficiência cardíaca e insuficiência mitral moderada/grave submetidos a substituição valvar mitral com a técnica da papilopexia cruzada e constrição anular. MÉTODOS: Treze pacientes em classe funcional III ou IV (NYHA, idade média de 54,1 anos, etiologia idiopática, foram submetidos a substituição valvar mitral com constrição do anel e papilopexia cruzada. Foram analisados os parâmetros ecocardiográficos, classe funcional e curva atuarial de sobrevivência. RESULTADOS: Não houve mortes no período trans e pósoperatório imediato. A média dos diâmetros diastólicos e sistólicos ventricular esquerdo reduziu de 71 ± 8,6 mm para 65,3 ± 8,6 mm (p=0,049 e de 59,1 ± 8,5 mm para 50,4 ± 11,1 mm (p=0,002, respectivamente. Os diâmetros atriais variaram de 49,4 ± 6,4 mm para 44 ± 5,9 mm (p=0,017; o percentual de encurtamento sistólico do ventrículo esquerdo foi de 17 ± 4% para 24 ± 8,3% (p=0,014, a fração de ejeção variou de 34 ± 9% para 45 ± 14% (p=0,008, todos estatisticamente significativos. Onze (84,6% pacientes se encontram em classe funcional I e II. A sobrevivência foi de 100%, 82,6%, 71,6%, respectivamente para 1, 6 e 12 meses após a cirurgia de seguimento, mantendo-se 71,6% em período superior a 36 meses. CONCLUSÃO: Os resultados obtidos, em pacientes com insuficiência cardíaca e insuficiência mitral moderada/grave submetidos a substituição valvar mitral com papilopexia cruzada e constrição anular, apresentaram evidências de remodelamento cardíaco favorável e significativa recuperação funcional ventricular esquerda.OBJECTIVE: To analyze the short-term and mid-term follow-ups of patients with heart failure and moderate to severe mitral valve insufficiency and who have undergone mitral valve replacement with crossed papillopexy and annular constriction. METHODS: Thirteen patients in NYHA functional class III or

  2. A Clinicopathological Study on Aortic Valves in Children

    Institute of Scientific and Technical Information of China (English)

    HUANG Ping; WANG Hongwei; ZHANG Zhenlu; HU Xiufen; LI Yanping; CHENG Peixuan; LIU Jianying

    2007-01-01

    In order to investigate the clinicopathological characteristics of aortic valve disease in children, all the native surgically excised aortic valves obtained between January 2003 and December 2005 were studied macroscopically and microscopically. The patients' medical records were reviewed and the clinical information was extracted. According to preoperative echocardiography, intraoperative assessment, and postoperative pathology, combined with clinical symptoms and signs, aortic valve diseases were divided into three categories: aortic stenosis (AS), aortic insufficiency (AI), and aortic stenosis with insufficiency (AS-AI). The etiology was determined according to the macroscopic, microscopic and clinical findings. The results showed that among 70 aortic valves, patient age ranged from 6 to 18 years, with a mean of 15.4 years, and there were 56 boys and 14 girts (male: female=4:1). Forty-four children only had pure aortic valve disease, and the other 26 children had aortic valve disease associated with other heart valve diseases. There were 5 cases of AS (7.14%), 60 cases of AI (85.71%) and 5 cases of AS-AI (7.14%). The causes were congenital aortic valve malformation (32 cases, 45.71%), rheumatic disease (28 cases, 40%), infective endocarditis (7 cases,10%), Marfan syndrome (2 cases, 2.86%), and undetermined (1 case, 1.43%). It was concluded that the common causes of aortic valve disease in order of frequency in children were congenital aortic valve malformation, rheumatic disease, infective endocarditis, and Marfan syndrome. AI was more common in children with aortic valve disease. Compared with adult patients, congenital bicuspid aortic valve in children was often AI. Histologically, the leaflets of congenital bicuspid aortic valve were mainly myxomatous, fibrosis and calcification less seen. AI was frequently found in rheumatic disease, mostly associated with other heart valve diseases. Macroscopic and microscopic examinations together with clinical

  3. Adjustable safety relief valve

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, W.L.

    1990-06-12

    This patent describes a pressure relief valve having a relief set pressure. It comprises: a valve body having a fluid inlet and outlet, a spherical, metal valve seat associated with the inlet and a valve member comprising at least a portion of a spherical,metal ball attached to a ball holding element, the valve member being biased against the valve seat and thus providing a metal-to-metal seal preventing the passage of fluids past the valve seat when the fluid pressure in the inlet is below the relief pressure setting of the valve.

  4. LV reverse remodeling imparted by aortic valve replacement for severe aortic stenosis; is it durable? A cardiovascular MRI study sponsored by the American Heart Association

    Directory of Open Access Journals (Sweden)

    Caruppannan Ketheswaram

    2011-04-01

    Full Text Available Abstract Background In patients with severe aortic stenosis (AS, long-term data tracking surgically induced effects of afterload reduction on reverse LV remodeling are not available. Echocardiographic data is available short term, but in limited fashion beyond one year. Cardiovascular MRI (CMR offers the ability to serially track changes in LV metrics with small numbers due to its inherent high spatial resolution and low variability. Hypothesis We hypothesize that changes in LV structure and function following aortic valve replacement (AVR are detectable by CMR and once triggered by AVR, continue for an extended period. Methods Tweny-four patients of which ten (67 ± 12 years, 6 female with severe, but compensated AS underwent CMR pre-AVR, 6 months, 1 year and up to 4 years post-AVR. 3D LV mass index, volumetrics, LV geometry, and EF were measured. Results All patients survived AVR and underwent CMR 4 serial CMR's. LVMI markedly decreased by 6 months (157 ± 42 to 134 ± 32 g/m2, p 2. Similarly, EF increased pre to post-AVR (55 ± 22 to 65 ± 11%,(p 2. LV stroke volume increased rapidly from pre to post-AVR (40 ± 11 to 44 ± 7 ml, p Conclusion After initial beneficial effects imparted by AVR in severe AS patients, there are, as expected, marked improvements in LV reverse remodeling. Via CMR, surgically induced benefits to LV structure and function are durable and, unexpectedly express continued, albeit markedly incomplete improvement through 4 years post-AVR concordant with sustained improved clinical status. This supports down-regulation of both mRNA and MMP activity acutely with robust suppression long term.

  5. Innovations in minimally invasive mitral valve pair.

    Science.gov (United States)

    Sündermann, Simon H; Seeburger, Joerg; Scherman, Jacques; Mohr, Friedrich Wilhelm; Falk, Volkmar

    2012-12-01

    Mitral valve (MV) insufficiency is the second most common heart valve disease represented in cardiac surgery. The gold standard therapy is surgical repair of the valve. Today, most centers prefer a minimally invasive approach through a right-sided mini-thoracotomy. Despite the small access, there is still the need to use cardiopulmonary bypass (CPB), and the operation has to be performed on the arrested heart. New devices have been developed to optimize the results of surgical repair by implementing mechanisms for post-implantation adjustment on the beating heart or the avoidance of CPB. Early attempts with adjustable mitral annuloplasty rings go back to the early 1990s. Only a few devices are available on the market. Recently, a mitral valve adjustable annuloplasty ring was CE-marked and is under further clinical investigation. In addition, a sutureless annuloplasty band to be implanted on the beating heart is under preclinical and initial clinical investigation for transatrial and transfemoral transcatheter implantation. Furthermore, new neochord systems are being developed, which allow for functional length adjustment on the beating heart after implantation. Some devices were developed for percutaneous MV repair implanted into the coronary sinus to reshape the posterior MV annulus. Other percutaneous devices are directly fixed to the posterior annulus to alter its shape. Several disadvantages have been observed preventing a broad clinical use of some of these devices. There is a continuous effort to develop innovative techniques to optimize MV repair and to decrease invasiveness. PMID:23315719

  6. Exercise Testing Induces Fatal Thromboembolism: from Mechanical Mitral Valve

    OpenAIRE

    Yavuzgil, Oguz; Ozerkan, Filiz; Gurgun, Cemil; Zoghi, Mehdi; Can, Levent.; AKIN, Mustafa

    2002-01-01

    Thromboembolism is still one of the most important complications of prosthetic heart valves. Embolism to a major coronary branch is rare, but acute proximal occlusions can be fatal, even when the coronary arteries are otherwise normal and intervention is rapid. We report a fatal complication of an exercise test in a patient who had a St. Jude bileaflet mitral valve.

  7. Hydrodynamic performance of a prototype bioprosthetic valve derived from the pulmonary valve of Phoca groenlandica.

    Science.gov (United States)

    Agathos, E Andreas; Shen, Ming; Styrc, Witold; Giannakopoulou, Stamatina; Lachanas, Elias; Tomos, Perikles

    2012-01-01

    Biological valves offer significant advantages over mechanical valves, and for this reason, we studied the possibility of using a new animal source such as that of Phoca groenlandica. Four aortic and four pulmonary leaflets were cut radially and their uniaxial tensile testing was evaluated. Three prototype pulmonary valves of Phoca groenlandica preserved in buffered glutaraldehyde solution 0.625% at pH 7.4 were mounted on a 19, 21, and 27 mm novel support system (stent) with heart shape commissural posts covered with polytetrafluoroethylene. The valves were tested in a steady flow system, the peak pressure gradients (PPGs) were measured, and the effective orifice areas (EOAs) were calculated for the flows of 3, 4, 5, 6, and 8 L/min. There were five different measurements for each flow variant. Aortic and pulmonary leaflets present no statistically significant difference in failure strength (p = 0.93). The PPGs across the valves for the flow of 3, 4, 5, 6, and 8 L/min for all three tested valves were low and the corresponding calculated EOAs were large. The new bioprosthetic valve derived from the pulmonary valve of Phoca groenlandica mounted on this novel support system presented a satisfactory hydrodynamic performance in a steady flow system. More research is needed before it can be considered suitable for human cardiac valve replacement. PMID:22929892

  8. Anticoagulant management of pregnant women with mechanical heart valve replacement during perioperative period%心脏瓣膜置换术后妊娠妇女围手术期的抗凝管理

    Institute of Scientific and Technical Information of China (English)

    綦小蓉; 边策; 李黎; 赵际童; 刘兴会

    2015-01-01

    Objective: To investigate suitable anticoagulation in perioperative with women who received mechanical heart valve replacement. Method:34 pregnant women with mechanical heart valve replacement who received low-dose oral anticoagulation treatment from Oct. 2008 to Jul. 2012 treated at West China Women's and Children's Hospital were retrospec-tively reviewed. 7 patients received emergency cesarean section,while 27 patients received se-lective cesarean section,in which 13 patients received single oral warfarin postpartum and 14 patients received “bridging treatment”. Morbidity of complications and the time to achieve the target INR after operation were compared. Results:34 full-terms healthy babies were delivered and no maternal thromboembolic was observed during pregnancy. There was no significant difference of the amount of vaginal bleeding between single oral warfarin group and “bridging treatment” group during postpartum period. In single oral warfarin group,one valve thrombosis was observed and leaded to sudden death. No periphery thrombosis,hematoma,general hemor-rhage or other sign of over-anticoagulation was observed. The INR increased more slowly in the group who received emergency operation with preoperative application of vitamin K1 than other two groups. Conclusion:The use of vitamin K1 preoperatively might result in warfarin resistance and discontinue warfarin therapy before selective cesarean section might be more appropriate than application of vitamin K1. The “ bridging treatment” which combines oral warfarin and subcutaneous LMWH might be more effective and safer than single oral warfarin therapy for pa-tients with mechanical heart valve replacement during postoperative period,no matter selective or emergency cesarean section. The safty of low-dose oral wafarin therapy thoughout preganancy is still under controversy.%目的::探讨心脏机械瓣膜置换术后妊娠妇女围手术期适宜的抗凝方案。方法:回顾分析2008

  9. Morphological aspects of atrioventricular valves in the ostrich (Struthio camelus

    Directory of Open Access Journals (Sweden)

    Marco A. Pereira-Sampaio

    2013-11-01

    Full Text Available Heart anatomy in the ostrich has been reported, but there are few information on the histological features of the atrioventricular valves. Hearts of young ostriches were fixed in 10% formaldehyde for 24 h and dissected to characterize their macroscopic anatomy. Samples of valves were harvested and stained with Mallory’s trichrome, Gomori’s trichrome, and Picro-Sirius red, for later analysis. The right atrioventricular valve consists of a muscle flap with two fixations. The left atrioventricular valve consists of two layers of endocardium with a layer of connective tissue between them. The free border of the tricuspid valve supports a varying number of chordae tendineae. One of the cusps is attached to the septum, while the other two cusps are attached to the opposite wall. The aortic valve, as well as the pulmonary trunk valve, consists of three cusps. The right atrioventricular valve showed up only as a muscle flap of myocardium coated with a thin layer of dense connective tissue, with two fixations. In the connective tissue, we find a predominance of type I collagen fibers and a lesser amount of type III, with a small presence of elastic fibers. The presence of Purkinje fibers were also usual in the valvular subendocardium, suggesting that they directly participate in the transmission of nervous stimulation to the muscle fibers within the valves. The left atrioventricular valve consisted of 3 cusps, a dorsal, a left, and a right.

  10. Recent developments for surgical aortic valve replacement: the concept of sutureless valve technology

    OpenAIRE

    Carrel, Thierry; Englberger, Lars; Stalder, Mario

    2013-01-01

    Aortic stenosis has become the most frequent type of valvular heart disease in Europe and North America and presents in the large majority of patients as calcified aortic stenosis in adults of advanced age. Surgical aortic valve replacement has been recognized to be the definitive therapy which improves considerably survival for severe aortic stenosis since more than 40 years. In the most recent period, operative mortality of isolated aortic valve replacement for aortic stenosis varies betwee...

  11. An Adult Case of Unicommissural Unicuspid Aortic Valve Diagnosed Based on the Intraoperative Findings.

    Science.gov (United States)

    Yamanaka, Tetsuo; Fukatsu, Toru; Ichinohe, Yoshimaro; Komatsu, Hirotaka; Seki, Masahiro; Sasaki, Kenichi; Takai, Hideaki; Kunihara, Takashi; Hirata, Yasunobu

    2016-01-01

    We herein report an adult case of unicommissural unicuspid aortic valve (UAV). A 59-year-old man, who was noted to have a cardiac murmur at 31 years of age, was admitted to our hospital due to acute heart failure. Severe calcification in the aortic valve with severe low-flow/low-gradient aortic stenosis and moderate aortic regurgitation was observed and thought to be the cause of heart failure, however, the etiology of aortic valve dysfunction was not clear. Aortic valve replacement was subsequently performed, and unicommissural UAV was diagnosed according to the intraoperative findings. UAV is very rare congenital aortic valve disease which is rarely diagnosed preoperatively.

  12. Remote actuated valve implant

    Science.gov (United States)

    McKnight, Timothy E; Johnson, Anthony; Moise, Jr., Kenneth J; Ericson, Milton Nance; Baba, Justin S; Wilgen, John B; Evans, III, Boyd McCutchen

    2014-02-25

    Valve implant systems positionable within a flow passage, the systems having an inlet, an outlet, and a remotely activatable valve between the inlet and outlet, with the valves being operable to provide intermittent occlusion of the flow path. A remote field is applied to provide thermal or magnetic activation of the valves.

  13. Microfluidic sieve valves

    Science.gov (United States)

    Quake, Stephen R; Marcus, Joshua S; Hansen, Carl L

    2015-01-13

    Sieve valves for use in microfluidic device are provided. The valves are useful for impeding the flow of particles, such as chromatography beads or cells, in a microfluidic channel while allowing liquid solution to pass through the valve. The valves find particular use in making microfluidic chromatography modules.

  14. Remote actuated valve implant

    Energy Technology Data Exchange (ETDEWEB)

    McKnight, Timothy E.; Johnson, Anthony; Moise, Kenneth J.; Ericson, Milton Nance; Baba, Justin S.; Wilgen, John B.; Evans, Boyd Mccutchen

    2016-05-10

    Valve implant systems positionable within a flow passage, the systems having an inlet, an outlet, and a remotely activatable valve between the inlet and outlet, with the valves being operable to provide intermittent occlusion of the flow path. A remote field is applied to provide thermal or magnetic activation of the valves.

  15. Percutaneous aortic valve replacement using a W-model valved stent: a preliminary feasibility study in sheep

    Institute of Scientific and Technical Information of China (English)

    BAI Yuan; ZONG Gang-jun; WANG Yan-yan; JIANG Hai-bin; LI Wei-ping; WU Hong; ZHAO Xian-xian; QIN Yong-wen

    2009-01-01

    Background Percutaneous aortic valve replacement is a promising strategy in the treatment of patients with aortic valve stenosis. And many kinds of valved stents have been implanted in selected patients worldwide. However, the clinical experience is still limited. We developed a W-model valved stent and evaluated the feasibility and safety of percutaneous implantation of the device in the native aortic valve position.Methods A self expanding nitinol stent with W-model, containing porcine pericardium valves in its proximal part, was implanted in six sheep by means of a 14 French catheter through the right common lilac artery under guidance of fluoroscopy. During stent deployment the original aortic valve was pushed against the aortic wall by the self expanding force of the stent while the new valve was expanded. These sheep were followed up shortly after procedure with supra-aortic angiogram and left ventriculography. Additionally, one sheep was sacrificed after the procedure for anatomic evaluation.Results It was possible to replace the aortic valve in the beating heart in four sheep. The procedure failed in two sheep due to coronary orifice occlusion in one case and severe aortic valve regurgitation in the other case. One sheep was killed one hour after percutaneous aortic valve replacement for anatomic evaluation. There were no signs of damage of the aortic intima, or of obstruction of the coronary orifice.Conclusions Percutaneous aortic valve replacement with a W-model valved stent in the beating heart is possible. Further studies are mandatory to assess safety and efficacy of this kind of valved stent in larger sample size and by longer follow-up period.

  16. Valve-in-Valve Replacement Using a Sutureless Aortic Valve

    Science.gov (United States)

    Dohmen, Pascal M.; Lehmkuhl, Lukas; Borger, Michael A.; Misfeld, Martin; Mohr, Friedrich W.

    2016-01-01

    Patient: Female, 61 Final Diagnosis: Tissue degeneration Symptoms: Dyspnea Medication: — Clinical Procedure: Redo valve replacement Specialty: Surgery Objective: Rare disease Background: We present a unique case of a 61-year-old female patient with homograft deterioration after redo surgery for prosthetic valve endocarditis with root abscess. Case Report: The first operation was performed for type A dissection with root, arch, and elephant trunk replacement of the thoracic aorta. The present re-redo surgery was performed as valve-in-valve with a sutureless aortic biopros-thesis. The postoperative course was uneventful and the patient was discharged on day 6. Conclusions: The current case report demonstrates that sutureless bioprostheses are an attractive option for surgical valve-in-valve procedures, which can reduce morbidity and mortality. PMID:27694795

  17. Are valve repairs associated with better outcomes than replacements in patients with native active valve endocarditis?

    Science.gov (United States)

    Zhao, Dong; Zhang, Benqing

    2014-12-01

    A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether valve replacement was associated with higher morbidity and mortality rates than valve repair in patients with native active valve endocarditis. Altogether 662 papers were found using the reported search, of which 7 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. Traditionally, valve replacement has been the standard therapy for valve endocarditis when surgical treatment is indicated. But now valve repair is increasingly used as an alternative, which may avoid disadvantages of anticoagulation, lower the risk of prosthetic infection and improve postoperative survival. To compare outcomes of these two treatments between studies can be difficult because most of related papers contain raw data on prosthetic valve endocarditis or healed endocarditis, which were excluded from our manuscript. Studies only analysing the outcomes of either of these treatments without the comparison of valve repair and replacement were also excluded. Finally, seven papers were identified. The American Heart Association/American College of Cardiology 2006 valvular guidelines recommended that mitral valve repair should be performed instead of replacement when at all possible. In three of the seven studies, there were significant differences between valve repair and replacement in long-term survival. One study found that aortic valve repair offered better outcomes in freedom from reoperation at 5 years (P = 0.021) and in survival at 4 years (repair vs replacement 88 vs 65%; P = 0.047). One study reported that there was improved event-free survival at 10 years in the mitral valve repair group (P = 0.015), although there was more previous septic embolization in this group. In one study, early and late mortality

  18. Comparison between three types of stented pericardial aortic valves (Trivalve trial): study protocol for a randomized controlled trial

    OpenAIRE

    Azarnoush, Kasra; Pereira, Bruno; Dualé, Christian; Dorigo, Enrica; Farhat, Mehdi; Innorta, Andrea; Dauphin, Nicolas; Geoffroy, Etienne; Chabrot, Pascal; Camilleri, Lionel

    2013-01-01

    International audience BackgroundAortic valve stenosis is one of the most common heart diseases in older patients. Nowadays, surgical aortic valve replacement is the 'gold standard' treatment for this pathology and the most implanted prostheses are biological ones. The three most implanted bovine bioprostheses are the Trifecta valve (St. Jude Medical, Minneapolis, MN, USA), the Mitroflow valve (Sorin Group, Saluggia, Italy), and the Carpentier-Edwards Magna Ease valve (Edwards Lifesciences...

  19. Plastik på trikuspidalklappen (Tricuspid valve annuloplasty. The neglected valve)

    DEFF Research Database (Denmark)

    Pedersen, Thais A L; Wierup, Per; Pedersen, Lia Mendes;

    2010-01-01

    INTRODUCTION: Tricuspid valve regurgitation (TVR) is often secondary to left-sided or congenital heart disease (CHD). Surgical correction of TVR is indicated when the primary abnormalities require operation. MATERIAL AND METHODS: Retrospective analysis of all 50 patients (mean age: 65 years (range......: 24-83), 27 males, 23 females) operated with tricuspid valve annuloplasty (TVA) in our hospital from 2000 to 2007. TVA took place concomitantly with operation for left heart disease (n = 39, 78%) or CHD (n = 11, 22%). RESULTS: Preoperatively, TVR was severe in 40, moderate in six and mild in four....... There were five (10%) early and two (4%) late deaths. Temporary arrhythmias requiring medical treatment occurred in 35 cases, but eight required permanent pacemaker. No tricuspid valve reoperations were performed. CONCLUSIONS: The combination of correction of primary heart abnormalities and TVA is associated...

  20. Heart Attack or Sudden Cardiac Arrest: How Are They Different?

    Science.gov (United States)

    ... for Heart360 Cardiovascular Conditions • Conditions Home • Arrhythmia and Atrial Fibrillation • Cardiac Arrest • Cardiac Rehab • Cardiomyopathy • Cardiovascular Conditions of Childhood • Cholesterol • Congenital Heart Defects • Diabetes • Heart Attack • Heart Failure (HF) • Heart Valve Problems and Disease • High Blood ...

  1. Morphometric analysis of tricuspid valve: An Indian perspective

    Science.gov (United States)

    Kalyani, R.; Thej, M. J.; Prabhakar, K.; Venkatesh, T. K.; Thomas, A. K.; Kiran, J.

    2012-01-01

    Background: The morphometry of tricuspid valve complex is of clinical importance for cardiovascular surgeons and there is scarcity of such data in Indian literature. The study was conducted to record normal tricuspid valve measurements which would serve as baseline data for the Indian population. Material and Methods: The study was carried out on 100 formalin fixed hearts without any pathology from patients who had died of non-vascular causes and whose age ranged from 8 to 85 yrs. The hearts were grouped into three cohorts corresponding to age, 54 hearts aged between 8 to 40 yrs, 42 hearts aged between 41 to 64 yrs and 4 hearts aged 65 yrs and above. Dissection was performed according to standard autopsy techniques. The measurements were recorded using a flexible millimeter ruler and surgical suture material. The dimensions measured were the attachment lengths of anterior, posterior and septal leaflets. The circumference of the valve along with the frontal and sagittal dimensions was measured. Area of the valve expressed as a triangle and as an ellipse was calculated. Results: The measurements obtained were assessed using SPSS software. Statistically significant increase in tricuspid valve measurements were observed with advancing age both in men and women. In younger hearts the tricuspid valve resembled a triangle and with advancing age the tricuspid valve became more elliptical in shape. Conclusion: We hope this study will serve as baseline data for the tricuspid valve measurements in the Indian population and it will be of clinical use for patients with various tricuspid valve abnormalities. PMID:23225976

  2. Three-dimensional echocardiography in valve disease

    Directory of Open Access Journals (Sweden)

    Cesare Fiorentini

    2009-08-01

    Full Text Available This review covers the role of three-dimensional (3D echocardiography in the diagnosis of heart valve disease. Several factors have contributed to the evolution of this technique, which is currently a simple and routine method: rapid evolution in probe and computer technologies, demonstration that 3D data sets allowed more complete and accurate evaluation of cardiac structures, emerging clinical experience indicating the strong potential particularly in valve diseases, volume and function of the two ventricle measurements and several other fields. This report will review current and future applications of 3D echocardiography in mitral, aortic and tricuspid valve diseases underlying both qualitative (morphologic and quantitative advantages of this technique. (Heart International 2007; 3: 35-41

  3. Effect of single intraoperative dose of amiodarone in patients with rheumatic valvular heart disease and atrial fibrillation undergoing valve replacement surgery

    Directory of Open Access Journals (Sweden)

    Selvaraj Thiruvenkadam

    2009-01-01

    Full Text Available Maintenance of sinus rhythm (SR is superior to rate control in atrial fibrillation (AF. In order to achieve SR, we administered single-dose intravenous amiodarone intraoperatively and evaluated its effect on conversion of rheumatic AF to SR in patients undergoing valvular heart surgery. Patients were randomly assigned to amiodarone ( n = 42 or control ( n = 40 group in a double blind manner. The amiodarone group received amiodarone (3 mg/kg intravenously prior to the institution of cardiopulmonary bypass and the control group received the same volume of normal saline. In the amiodarone group, the initial rhythm after the release of aortic cross clamp was noted to be AF in 14.3% ( n = 6 and remained so in 9.5% ( n = 4 of patients till the end of surgery. In the control group, the rhythm soon after the release of aortic cross clamp was AF in 37.5% ( n = 15 ( p = 0.035 and remained so in 32.5% ( n = 13 of patients till the end of surgery ( p = 0.01. At the end of first post-operative day 21.4% ( n = 9 of patients in amiodarone group and 55% ( n = 22 of patients in control group were in AF ( p = 0.002. The requirement of cardioversion/defibrillation was 1.5 (±0.54 in amiodarone group and 2.26 (±0.73 in the control group ( p = 0.014, and the energy needed was 22.5 (±8.86 joules in the amiodarone group and 40.53 (±16.5 in the control group ( p = 0.008. A single intraoperative dose of intravenous amiodarone increased the conversion rate of AF to normal sinus rhythm, reduced the need and energy required for cardioversion/defibrillation and reduced the recurrence of AF within one day.

  4. Aortic Valve Replacement in Young Adults

    NARCIS (Netherlands)

    L.M.A. Klieverik (Loes Maria Anne)

    2007-01-01

    textabstractWorldwide the incidence and burden of heart valve disease is increasing due to aging of the world population and the problem of rheumatic cardiac disease in developing countries and in parts of the population in the developed world.1 Between 2007 and 2050 the world population will increa

  5. Palliative Mitral Valve Repair During Infancy for Neonatal Marfan Syndrome.

    Science.gov (United States)

    Kitahara, Hiroto; Aeba, Ryo; Takaki, Hidenobu; Shimizu, Hideyuki

    2016-05-01

    An infant with neonatal Marfan syndrome (nMFS), a condition that is nearly always lethal during infancy, was referred to our hospital with symptoms of congestive heart failure resulting from severe mitral valve insufficiency. During mitral valve repair, the use of an annuloplasty ring was waived until annular dilatation was achieved after 2 palliative mitral valvuloplasty procedures. After the definitive operation, the patient's mitral valve function remained within normal limits until the last follow-up when the patient was 11 years old. To the best of our knowledge, this patient has the longest recorded survival after mitral valve repair. PMID:27106438

  6. Percutaneous pulmonary valve implantation in a single artery branch: A preliminary experience

    Institute of Scientific and Technical Information of China (English)

    Massimo; Chessa; Gianfranco; Butera; Luca; Giugno; Angelo; Micheletti; Diana; G; Negura; Mario; Carminati

    2015-01-01

    To describe preliminary experience of percutaneous pulmonary valve implantation, in a single pulmonary branch position. Two procedures in 2 patients from a single center are described, where implantation of percutaneous valves within a single pulmonary artery branch was technically successful. The procedural indication was pulmonary valve regurgitation and/or residual stenosis. The 2 patients were symptomatic. An Edwards Sapien? valve(Patient 1), and a Medtronic Melody? valve(Patient 2) were implanted. Both pts were discharged with an excellent valve function. In this report it is underlined that this modality is technically feasible and may be considered an option in patients with congenital heart defect under special circumstances.

  7. 心脏瓣膜间质细胞的表型转化及其与瓣膜病理形态发生的关系%The relationship between phenotypic regulation of the rheumatic heart valve interstitial population and pathological formation

    Institute of Scientific and Technical Information of China (English)

    牛建立; 成杞润; 贾清仁; 邓永江; 刘光

    2001-01-01

    Objective:To investigate the relationship between the phenotypic regulation of the rheumatic heart valve interstitial population and the biological mechanism of pathological formation.Methods:A series of human heart valve tissues of 75 patients with rheumatic heart disease was obtained during surgical intervention and was classified to typeⅠ,Ⅱ,Ⅲ according to its gross features,the expression of proliferating cell nuclear antigen(PCNA),α1(Ⅰ) procollagen(PCα1Ⅰ) and αsmooth muscle actin(αSMA) were determined using immunohistochemical techniques.Results:PCNA was present largely in both type Ⅰ and type Ⅱ and little or absent in type Ⅲ or normal heart valves.αSMA was present little in both normal heart valves and type Ⅰ and increased in type Ⅱ and type Ⅲ,the expression of PCα1Ⅰ increased as the development of valve pathological morphology and was present heavily in type Ⅲ.Conclusions:The human heart valve interstitial population undertake the phenotypic properties of proliferation,synthesis of collagen and contraction,which may be central to the cellular mechanism of valvular pathological formation in rheumatic heart disease.%目的:研究风湿性心脏病瓣膜间质细胞的表型转化规律,探讨其与瓣膜病理形态发生的关系。方法:手术切除风湿性心脏瓣膜系列组织标本75例,依据大体病理形态进行分类,通过免疫组织化学方法进行瓣膜组织中间质细胞表达增殖细胞核抗原(PCNA)、α平滑肌肌动蛋白(αSMA)和α1(Ⅰ)型前胶原蛋白(PCα1Ⅰ)检测。结果:PCNA蛋白表达主要集中在Ⅰ、Ⅱ型瓣膜组织中,Ⅲ型及正常人瓣膜组织间质细胞内呈弱表达或无表达;正常人及Ⅰ型瓣膜组织有少量αSMA阳性细胞表达,Ⅱ、Ⅲ型瓣膜组织中αSMA阳性细胞表达逐渐增加;PCα1Ⅰ表达随病理形态发展逐渐增加,在Ⅲ型病变组织中最高。结论:心脏瓣膜间质细胞在

  8. Computer Simulation of the Beating Human Heart

    Science.gov (United States)

    Peskin, Charles S.; McQueen, David M.

    2001-06-01

    The mechanical function of the human heart couples together the fluid mechanics of blood and the soft tissue mechanics of the muscular heart walls and flexible heart valve leaflets. We discuss a unified mathematical formulation of this problem in which the soft tissue looks like a specialized part of the fluid in which additional forces are applied. This leads to a computational scheme known as the Immersed Boundary (IB) method for solving the coupled equations of motion of the whole system. The IB method is used to construct a three-dimensional Virtual Heart, including representations of all four chambers of the heart and all four valves, in addition to the large arteries and veins that connect the heart to the rest of the circulation. The chambers, valves, and vessels are all modeled as collections of elastic (and where appropriate, actively contractile) fibers immersed in viscous incompressible fluid. Results are shown as a computer-generated video animation of the beating heart.

  9. Evaluation of mitral valve replacement anchoring in a phantom

    Science.gov (United States)

    McLeod, A. Jonathan; Moore, John; Lang, Pencilla; Bainbridge, Dan; Campbell, Gordon; Jones, Doug L.; Guiraudon, Gerard M.; Peters, Terry M.

    2012-02-01

    Conventional mitral valve replacement requires a median sternotomy and cardio-pulmonary bypass with aortic crossclamping and is associated with significant mortality and morbidity which could be reduced by performing the procedure off-pump. Replacing the mitral valve in the closed, off-pump, beating heart requires extensive development and validation of surgical and imaging techniques. Image guidance systems and surgical access for off-pump mitral valve replacement have been previously developed, allowing the prosthetic valve to be safely introduced into the left atrium and inserted into the mitral annulus. The major remaining challenge is to design a method of securely anchoring the prosthetic valve inside the beating heart. The development of anchoring techniques has been hampered by the expense and difficulty in conducting large animal studies. In this paper, we demonstrate how prosthetic valve anchoring may be evaluated in a dynamic phantom. The phantom provides a consistent testing environment where pressure measurements and Doppler ultrasound can be used to monitor and assess the valve anchoring procedures, detecting pararvalvular leak when valve anchoring is inadequate. Minimally invasive anchoring techniques may be directly compared to the current gold standard of valves sutured under direct vision, providing a useful tool for the validation of new surgical instruments.

  10. 骨唾液蛋白和基质金属蛋白酶-9在风湿性心脏病钙化瓣膜中的表达及意义%The expression and significance of bone sialoprotein and matrix metalloproteinase-9 in calcified valves of patients with rheumatic heart disease

    Institute of Scientific and Technical Information of China (English)

    白传明; 张彬; 张楠; 宋书田; 张志刚; 边玉清; 周岊梧

    2012-01-01

    Objective To observe the expression of bone sialoprotein (BSP) and matrix metalloproteinase-9 (MMP-9) in calcified valves of patients with rheumatic heart disease.Methods A total of 150 mitral valves which were resected by surgery were divided into rheumatic group ( 120 valves) and nonrheumatic group (30 valves).Immunohistochemical staining was taken by SP method and the expressions of BSP and MMP-9 in two groups were observed and compared.Results The positive expressions of BSP and MMP-9 in rheumatic group were 91.7%(110/120) and 90.8%(109/120),respectively,which were significantly higher than those in non-rheumatic group [23.3%(7/30) and 20.0%(6/30) ](P< 0.01 ).Conclusions The expressions of both BSP and MMP-9 are higher in the valves of patients with rheumatic heart disease.The calcification of rheumatic mitral valves is closely related with the degradation and remodeling of extracellular matrix caused by MMP-9,and osteoblast-like bone formation induced by BSP.%目的 观察骨唾液蛋白(BSP)和基质金属蛋白酶-9(MMP-9)在风湿性心脏病(风心病)钙化瓣膜中的表达情况.方法 将手术切除的二尖瓣瓣膜(共150枚)按病史分为风心病组(120枚)和非风心病组(30枚),采用SP法进行免疫组织化学染色,观察并比较两组BSP和MMP-9的表达情况.结果 风心病组BSP和MMP-9阳性表达率分别为91.7%(110/120)和90.8%(109/120),显著高于非风心病组的23.3%( 7/30)和20.0%(6/30),差异均有统计学意义(P<0.01).结论 风心病瓣膜BSP和MMP-9高表达,风心病瓣膜的钙化与MMP-9所引起的细胞外基质降解和重塑以及BSP所诱导的成骨样骨形成密切相关.

  11. Left atrial ball valve thrombus

    Directory of Open Access Journals (Sweden)

    R. Balaji

    2013-10-01

    Full Text Available "Ball valve thrombus" which is a spherical free floating clot in left atrium is an often quoted, but uncommonly encountered complication in patients with severe mitral stenosis of rheumatic origin, who are in atrial fibrillation. We describe the case of a 31-year-old lady with rheumatic heart disease, severe mitral stenosis and moderately severe aortic stenosis who had undergone closed mitral valvotomy 13 years ago. The patient presented with an episode of non-exertional syncope and breathlessness on exertion of 6 months duration and was in normal sinus rhythm. Echocardiography facilitated ante-mortem diagnosis and prompt institution of surgery was life saving.

  12. Absence of venous valves in mice lacking Connexin37.

    Science.gov (United States)

    Munger, Stephanie J; Kanady, John D; Simon, Alexander M

    2013-01-15

    Venous valves play a crucial role in blood circulation, promoting the one-way movement of blood from superficial and deep veins towards the heart. By preventing retrograde flow, venous valves spare capillaries and venules from being subjected to damaging elevations in pressure, especially during skeletal muscle contraction. Pathologically, valvular incompetence or absence of valves are common features of venous disorders such as chronic venous insufficiency and varicose veins. The underlying causes of these conditions are not well understood, but congenital venous valve aplasia or agenesis may play a role in some cases. Despite progress in the study of cardiac and lymphatic valve morphogenesis, the molecular mechanisms controlling the development and maintenance of venous valves remain poorly understood. Here, we show that in valved veins of the mouse, three gap junction proteins (Connexins, Cxs), Cx37, Cx43, and Cx47, are expressed exclusively in the valves in a highly polarized fashion, with Cx43 on the upstream side of the valve leaflet and Cx37 on the downstream side. Surprisingly, Cx43 expression is strongly induced in the non-valve venous endothelium in superficial veins following wounding of the overlying skin. Moreover, we show that in Cx37-deficient mice, venous valves are entirely absent. Thus, Cx37, a protein involved in cell-cell communication, is one of only a few proteins identified so far as critical for the development or maintenance of venous valves. Because Cxs are necessary for the development of valves in lymphatic vessels as well, our results support the notion of common molecular pathways controlling valve development in veins and lymphatic vessels.

  13. Clinical Pharmacists' Experience about the Practice of Anticoagulation Management of the Patients Who Had Been Discharged from Hospital after Undergoing Mechanical Heart Valve Replacement%临床药师参与心脏机械瓣膜置换术患者出院后抗凝管理的实践与体会

    Institute of Scientific and Technical Information of China (English)

    张海燕; 罗万慰; 马守梅

    2009-01-01

    To explore the function and approach of clinical pharmacists' participating in the anticoagulation management of patients who had been discharged from hospital after undergoing mechanical heart valve replacement. METHODS: The experiences of clinical pharmacists obtained through first-hand practice in the anticoagulation management and pharmaceutical care of the patients who had been discharged from hospital after undergoing mechanical heart valve replacement were introduced by illustrating examples. RESULTS & CONCLUSION: Clinical pharmacists' participating in the anticoagulation management of patients who had been discharged from hospital after undergoing mechanical heart valve replacement provide physicians and patients with pharmaceutical information and pharmaceutical care and enhance the effectiveness and safety of anticoagulative therapy accordingly.%目的:探讨临床药师参与心脏机械瓣膜置换术患者出院后抗凝治疗管理的作用和方法.方法:通过亲身实践,介绍我院临床药师参与抗凝管理工作及开展药学服务的体会,并结合典型实例分析说明.结果与结论:临床药师通过参与心脏机械瓣膜置换术患者出院后的抗凝管理工作,为医师及患者提供药学信息和药学服务,可提高抗凝治疗的安全性和有效性.

  14. Degenerative processes in bioprosthetic mitral valves in juvenile pigs

    Directory of Open Access Journals (Sweden)

    Pedersen Torben B

    2011-05-01

    Full Text Available Abstract Background Glutaraldehyde-treated bioprosthetic heart valves are commonly used for replacement of diseased heart valves. However, calcification and wear limit their durability, and the development of new and improved bioprosthetic valve designs is needed and must be evaluated in a reliable animal model. We studied glutaraldehyde-treated valves 6 months after implantation to evaluate bioprosthetic valve complications in the mitral position in juvenile pigs. Materials The study material comprised eight, 5-month old, 60-kg pigs. All pigs received a size 27, glutaraldehyde-treated, stented, Carpentier-Edwards S.A.V. mitral valve prosthesis. After six months, echocardiography was performed, and the valves explanted for gross examination, high resolution X-ray, and histological evaluation. Results Five pigs survived the follow-up period. Preexplant echocardiography revealed a median peak and mean velocity of 1.61 m/s (range: 1.17-2.00 and 1.20 (SD = ±0.25, respectively, and a median peak and mean pressure difference of 10.42 mmHg (range: 5.83-16.55 and 6.51 mmHg (SD = ±2.57, respectively. Gross examination showed minor thrombotic depositions at two commissures in two valves and at all three commissures in three valves. High resolution X-ray imaging revealed different degrees of calcification in all explanted valves, primarily in the commissural and belly areas. In all valves, histological evaluation demonstrated various degrees of fibrous sheath formation, limited immunological infiltration, and no overgrowth of host endothelium. Conclusions Bioprosthetic glutaraldehyde-treated mitral valves can be implanted into the mitral position in pigs and function after 6 months. Echocardiographic data, calcification, and histological examinations were comparable to results obtained in sheep models and human demonstrating the suitability of the porcine model.

  15. Mitral valve prolapse

    Science.gov (United States)

    ... seen with some connective tissue disorders such as Marfan syndrome and other rare genetic disorders. Symptoms Many ... 66. Read More Atrial septal defect (ASD) Endocarditis Marfan syndrome Mitral valve surgery - minimally invasive Mitral valve ...

  16. Recently patented transcatheter aortic valves in clinical trials.

    Science.gov (United States)

    Neragi-Miandoab, Siyamek; Skripochnik, Edvard; Salemi, Arash; Girardi, Leonard

    2013-12-01

    The most widely used heart valve worldwide is the Edwards Sapien, which currently has 60% of the worldwide transcatheter aortic valve implantation (TAVI) market. The CoreValve is next in line in popularity, encompassing 35% of the worldwide TAVI market. Although these two valves dominate the TAVI market, a number of newer transcatheter valves have been introduced and others are in early clinical evaluation. The new valves are designed to reduce catheter delivery diameter, improve ease of positioning and sealing, and facilitate repositioning or removal. The most recent transcatheter valves for transapical use include Acurate TA (Symetis), Engager (Medtronic), and JenaValve the Portico (St Jude), Sadra Lotus Medical (Boston Scientific), and the Direct Flow Medical. These new inventions may introduce more effective treatment options for high-risk patients with severe aortic stenosis. Improvements in transcatheter valves and the developing variability among them may allow for more tailored approaches with respect to patient's anatomy, while giving operators the opportunity to choose devices they feel more comfortable with. Moreover, introducing new devices to the market will create a competitive environment among producers that will reduce high prices and expand availability. The present review article includes a discussion of recent patents related to Transcatheter Aortic Valves. PMID:24279506

  17. Estudo comparativo das características fluidodinâmicas de próteses valvulares biológicas de pericárdio bovino de perfil alto e baixo Comparative study of fluid dynamic characteristics in high and low biological prosthetic heart valves from bovine pericardium

    Directory of Open Access Journals (Sweden)

    Aron J. P Andrade

    1989-12-01

    Full Text Available O comportamento fluidodinâmico e a vida útil média de uma prótese valvular cardíaca são características muito importantes na escolha do modelo de prótese a ser implantada em um determinado paciente. Por esse motivo, foi realizado um estudo comparativo entre as válvulas biológicas de perfil alto e baixo, para se verificarem possíveis alterações na vida média, gradiente de pressão e refluxo, causadas pela diminuição do perfil dessas próteses. Com o auxílio de um duplicador de pulso, foram analisadas cinco próteses de perfil alto e cinco de perfil baixo, todas tamanho 29, fabricadas no Instituto Dante Pazzanese de Cardiologia (IDPC. Mantendo-se a freqüência de batimentos em 100 bpm e a diferença de pressão em 1000 mmHg, verificou-se que a vida útil média da válvula de perfil baixo permaneceu equivalente à de perfil alto. Em outro equipamento, denominado simulador cardíaco, as próteses foram submetidas a condições semelhantes às condições fisiológicas de funcionamento para uma freqüência cardíaca de 75 bpm. Os resultados mostraram que o volume de retorno necessário para fechamento (refluxo, nas válvulas de perfil baixo, é menor do que nas de perfil alto. Isso traz um melhor aproveitamento do efeito de bombeamento do coração. As perdas de carga das válvulas foram comparadas através dos gradientes máximos de pressão visibilizados com a sobreposição dos sinais de pressão. Observou-se que as válvulas de perfil baixo oferecem menos resistência ao fluxo; assim, quando são implantadas, possibilitam uma passagem mais livre e desobstruída do sangue.The fluid dynamic performance and lifetime of a prosthetic heart valve are one of the most important characteristics to determine the choice of what prosthesis must be applied to a patient. Because of this, two different biological prosthetic heart valves profiles (one high profile and other low profile were studied, to verify possible alterations of working

  18. Aerodynamic Shutoff Valve

    Science.gov (United States)

    Horstman, Raymond H.

    1992-01-01

    Aerodynamic flow achieved by adding fixed fairings to butterfly valve. When valve fully open, fairings align with butterfly and reduce wake. Butterfly free to turn, so valve can be closed, while fairings remain fixed. Design reduces turbulence in flow of air in internal suction system. Valve aids in development of improved porous-surface boundary-layer control system to reduce aerodynamic drag. Applications primarily aerospace. System adapted to boundary-layer control on high-speed land vehicles.

  19. Transcatheter Pulmonary Valve Replacement

    OpenAIRE

    Ghawi, Hani; Kenny, Damien; Hijazi, Ziyad M.

    2012-01-01

    Transcatheter pulmonary valve replacement (tPVR) has evolved into a viable alternative to surgical conduit or bioprosthetic valve replacement. This procedure has paved the way for a more advanced approach to congenital and structural interventional cardiology. Although many successes have been noted, there are still a number of challenges with this procedure, including large delivery systems, the need for a conduit or a bioprosthetic valve as a landing zone for the valve, optimal timing of th...

  20. Isolated Pulmonary Valve Endocarditis

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Hatamizadeh

    2009-06-01

    Full Text Available Infective endocarditis is one of the most severe complications of parenteral drug abuse. The outstanding clinical feature of infective endocarditis in intravenous drug abusers is the high incidence of right-sided valve infection, and the tricuspid valve is involved in 60% to 70% of the cases. We herein report a case of isolated pulmonic valve infective endocarditis with a native pulmonary valve.

  1. Valve replacement in pediatric patients:a single center experience

    Institute of Scientific and Technical Information of China (English)

    YU Jian-hua; GUO Hong-wei; ZHANG Gong; WU Shu-ming; SONG Guang-min; SUN Wen-yu

    2011-01-01

    Background Reconstructive surgery is the primary goal in pediatric patients with valve disease.However,in cases with irreparable valve lesions,valve replacement is the only option.This study aimed to retrospectively analyze the clinical experience of heart valve prosthesis replacement in children.Methods Between January 1990 and July 2009,35 pediatric patients (16 boys,19 girls) underwent mechanical valve replacement in Shandong University Qilu Hospital.The ages ranged from 2.5 to 14 years (mean,(8.8±3.8) years) and body weight varied from 11 to 37 kg (mean,(22.1±5.2) kg).Mechanical valve replacement was performed because of congenital heart disease in 23 patients,rheumatic disease in ten patients and infective endocarditis in two patients.St.Jude bileaflet mechanical valves were implanted in all the 35 patients including mitral valve replacement (MVR) in 18,aortic valve replacement (AVR) in 12,tricuspid valve replacement (TVR) in two,AVR and MVR in two and MVR and TVR in one.The size of the prostheses ranged between 19 and 27 mm.All patients received long-term anticoagulation treatment with sodium warfarin,aiming to maintain an international normalized ratio between 1.5 to 2.0.Follow-up was performed in all the patients with a total follow-up of 119.4 patient-years.Results The operative mortality was 8.57% (3/35).One patient,who underwent cardiac debridement and AVR,died 2 hours after being admitted to the intensive care unit because of severe low cardiac output syndrome and ventricular fibrillation.Two patients died of cardiogenic shock and renal failure during initial hospitalization after the operation.One patient who received replacement of a tricuspid valve developed complete heart block requiring temporary pacing and recovered sinus rhythm 4 days later.Thirty-two patients survived and their cardiac function was in New York Heart Association (NYHA) class Ⅰ to class Ⅱ when discharged.Late events included hemorrhage and endocarditis.Two patients required

  2. A novel mathematical technique to assess of the mitral valve dynamics based on echocardiography

    CERN Document Server

    Karvandi, Mersedeh; Hassantash, Seyed Ahmad; Foroughi, Mahnoosh

    2015-01-01

    Purpose: The mechanics of the mitral valve leaflet as a nonlinear, inelastic and anisotropic soft tissue results from an integrated response of many mathematical/physical indexes' that illustrate the tissue. In the past decade, finite element modeling of complete heart valves has greatly aided evaluation of heart valve surgery, design of bioprosthetic valve replacements, and general understanding of healthy and abnormal cardiac function. Such a model must be based on an accurate description of the mechanical behavior of the valve material. It is essential to calculate velocity/displacement and strain rate/strain at a component level that is to work at the cellular level. In this study we developed the first three-dimensional displacement vectors field in the characterization of mitral valve leaflets in continuum equations of inelasticity framework based on echocardiography. Method: Much of our knowledge of abnormal mitral valve function is based on surgical and post-mortem studies while these studies are quan...

  3. 1例心脏病术后患者华法林抗凝治疗的用药分析%Analysis of Anticoagulant Therapy for a Patient after Mechanical Heart Valve Replacement

    Institute of Scientific and Technical Information of China (English)

    吴晓丽; 周玲

    2015-01-01

    1例46岁男性患者,既往有房颤及脑梗塞病史,二尖瓣机械瓣膜置换术后予以华法林抗凝治疗。根据药物基因检测及合并用药情况,初始给予华法林2.5 mg po qd,监测INR值偏低,华法林调整至3.75 mg po qd后出院,一月后复查INR 1.64。在随访过程中,临床药师发现该患者出院后自2014年10月至2015年1月,华法林剂量上调,但抗凝效果不佳,有栓塞风险。经详细了解后,考虑与患者服药依从性差相关,建议家属严格监督患者每日按时按量服用华法林,在饮食上避免长期摄入大量含有维生素K的食物并戒酒,一周后复查INR为1.46,接近合适范围。%A 46-year-old male patient, who has a history of atrial fibrillation and cerebral infarction, has taken warfarin-anticoagulant therapy after mechanical heart valve replacement. According to the results of drug genetic testing and drug combination, an abnormal low international standardization ration (INR) was observed when the initial warfarin dosage was 2.5 mg po qd, which indicated the risk of thrombosis. The warfarin dosage was adjusted to 3.75 mg po qd as the patient left hospital and then INR was 1.64 when rechecked one month later. At follow-up, with the increasing dosage of warfarin, the anticoagulant effect was not satisfactory from October 2014 to January 2015. After the detailed investigation, the clinical pharmacists considered the unsatisfactory anticoagulant effect was related to the poor compliance of the patient. The family dependents of the patient were advised to strictly supervise the patient to take warfarin timely and quantitatively and the patient was exhorted to avoid long-term foods with large amounts of vitamin K and forbear from alcohols. INR was 1.46 when rechecked one week later, which was close to the target range.

  4. 人工心瓣含硅低温热解炭涂层热处理分析%Analysis of Heat Treatment of Silicon-alloyed Low Temperature Pyrocarbon Coating for Artificial Heart Valves

    Institute of Scientific and Technical Information of China (English)

    喻主路; 张建辉

    2015-01-01

    Silicon-alloyed low temperature pyrocarbon coating for artificial heart valves was deposited by chemical vapor deposition ( CVD ) .The influence of heat treatment on the microstructure and mechanical properties of specimen was studied by X-ray diffraction , scanning electron microscopy , transmission electron microscopy , nanoindentation and dilatometer .The results show that the coating consists of two phases named pyrocarbon(turbostratic graphite-like structure) and β-SiC.After heat treatment the grain size of both become larger, and the carbon(002) planar spacing decreases which means the degree of graphitization of pyrocarbon improved.SEM and TEM show the material consists of spherical particles , and there exists pores among the particles.After heat treatment the pore structure of the material is changed , the number of large pores decreases, the pore distribution is more uniform .The changes in microstructure consequently cause the decrease of nano-hardness and increase of thermal expansion coefficient .%采用化学气相沉积法制备人工心瓣含硅低温热解炭涂层,并进行热处理。利用X射线衍射仪、扫描电子显微镜、透射电子显微镜、纳米压痕仪、热膨胀仪研究了热处理对涂层微观结构和性能的影响。结果表明,涂层包含热解炭(乱层石墨结构)与β-SiC两种物相,热处理后热解炭微晶层间距减小,表明石墨化程度提高,同时β-SiC微晶与热解炭微晶尺寸增大。电镜下材料主要由类球形颗粒组成,颗粒之间存在微米级孔隙,热处理后材料孔隙结构发生变化,大孔隙减少,孔隙分布更加均匀。热处理后材料纳米硬度明显减小,热膨胀系数略增大,微观结构的变化是导致材料性能改变的主要原因。

  5. Fibrinolytic therapy for mechanical pulmonary valve thrombosis.

    Science.gov (United States)

    Khajali, Zahra; Mohammadzadeh, Shabnam; Maleki, Majid; Peighambari, Mohammad Mehdi; Sadeghpoor, Anita; Ghavidel, Alireza; Elahi, Behrad; Mirzaaghayan, Mohammadreza

    2015-01-01

    Treatment of prosthetic heart valve thrombosis using intravenous thrombolytics, although an acceptable alternative to surgery, is not complication free, and the literature has a dearth of data on the subject. This study analyzed the results of fibrinolytic treatment (FT) among a single-center group of patients with mechanical pulmonary valve thrombosis. Between 2000 and 2013, 23 consecutive patients with 25 episodes of pulmonary valve thrombosis received FT. The diagnosis of mechanical pulmonary valve thrombosis was established by fluoroscopy and echocardiography. Streptokinase (SK) was used in 24 cases and alteplase in 1 case. The FT was continued a second day for 14 patients (58.3%), a third day for 1 patient, and a fourth day for 1 patient. Echocardiography and fluoroscopy were performed every day until improvement of malfunction was achieved. Of the 23 patients, 19 had complete resolution of hemodynamic abnormalities after FT, 1 had partial resolution, and 2 showed no change. No patient had major complications. Five minor complications were detected, namely, fever, nausea, thrombophlebitis, epistaxi, and pain. Seven patients (30%) experienced recurrence of thrombosis, whereas four patients had surgery (biological pulmonary valve replacement) without re-thrombolytic therapy, one patient was treated with Alteplase, one patient received SK, and one patient received intense anticoagulation using heparin and warfarin. Overall, FT had a success rate of 84%. The results indicate that regardless of the time to pulmonary valve replacement and echocardiographic and fluoroscopic findings, FT was effective in most cases of mechanical pulmonary valve thrombosis. The efficacy increased with second-day thrombolytic therapy. Major complications were not common after lytic therapy for mechanical pulmonary valve thrombosis.

  6. The change and significance of heart fatty acid-binding protein and cardiac troponin Ⅰ in valve replacement patients%心脏瓣膜置换围手术期H-FABP和cTnI的变化及意义

    Institute of Scientific and Technical Information of China (English)

    陈志军; 王永连; 王忠民

    2011-01-01

    目的 探讨心脏瓣膜置换术后心肌肌钙蛋白I(cTnI)和心型脂肪酸结合蛋白(H-FABP)的变化规律.方法 选本院风湿性心脏病手术患者40例,随机分为晶体停搏液灌注组和冷血停搏液灌注组,选取8个时间点,分析和比较各时点血清cTnI和H-FABP浓度变化规律.结果 晶体停搏液灌注组cTnI组间及交互效应差异均有统计学意义(F组间=2744.397,P<0.01; F交互=125.345,P<0.01),冷血停搏液灌注组cTnI组间及交互效应差异均有统计学意义(F组间=1056.357,P<0.01; F交互 =64.242,P<0.01);晶体停搏液灌注组H- FABP组间及交互效应差异均有统计学意义(F组间=1775.022,P<0.01;F交互=34.297,P<0.01),冷血停搏液灌注组H -FABP组间及交互效应差异均有统计学意义(F组间=3064.451,P<0.01;F交互=60.472,P<0.01).结论 H-FABP心肌的特异性强,有效诊断窗口期短,较符合心肌损伤的理想判定标志物.%Objective To explore change trend of Cardiac Troponin Ⅰ (cTnI) and Heart Fatty Acid-binding Protein(H-FABP) in serum during the perioperation of valve replacement.Methods Forty patients with heumatoid valvular heart disease were selected for this study,and the patients were randomly divided into two groups.Blood samples were taken from center vein,and the serum levels of cTnI and H-FABP were determined.The change of the serum levels of these two markers at different time points was recorded and compared between two groups.Results There were significant differences in the concentration of cTnl in the cold crystalloid cardioplegia group ( F between group =2744.397,P <0.01 ; F interaction =125.345,P <0.01 ).There were significant differences in the concentration of cTnI in the cold blood cardioplegia group ( F between group =1056.357,P < 0.01 ; Finteraction =64.242,P < 0.01 ).There were significant differences in the concentration of H - FABP in the cold crystalloid cardioplegia group ( F between group =1775.022,P <0.01; F

  7. Respiratory exposure control valve

    International Nuclear Information System (INIS)

    We have designed a new, three-way valve that separates inhaled and exhaled air in systems for inhalation exposure. A single-channel model of the valve was constructed and tested: with a control fluid pressure of 10 psi, the valve was cycled 36,000 times without diaphragm failure. No valve leakage was detected before or after the completion of the test. A 3-channel valve model was constructed this year and will undergo testing in FY 1979, followed by development and testing of the control system

  8. Heart Health - Brave Heart

    Science.gov (United States)

    ... Bar Home Current Issue Past Issues Cover Story Heart Health Brave Heart Past Issues / Winter 2009 Table of Contents For ... you can have a good life after a heart attack." Lifestyle Changes Surviving—and thriving—after such ...

  9. Main Oxidizer Valve Design

    Science.gov (United States)

    Addona, Brad; Eddleman, David

    2015-01-01

    A developmental Main Oxidizer Valve (MOV) was designed by NASA-MSFC using additive manufacturing processes. The MOV is a pneumatically actuated poppet valve to control the flow of liquid oxygen to an engine's injector. A compression spring is used to return the valve to the closed state when pneumatic pressure is removed from the valve. The valve internal parts are cylindrical in shape, which lends itself to traditional lathe and milling operations. However, the valve body represents a complicated shape and contains the majority of the mass of the valve. Additive manufacturing techniques were used to produce a part that optimized mass and allowed for design features not practical with traditional machining processes.

  10. Exercise echocardiography for structural heart disease.

    Science.gov (United States)

    Izumo, Masaki; Akashi, Yoshihiro J

    2016-03-01

    Since the introduction of transcatheter structural heart intervention, the term "structural heart disease" has been widely used in the field of cardiology. Structural heart disease refers to congenital heart disease, valvular heart disease, and cardiomyopathy. In structural heart disease, valvular heart disease is frequently identified in the elderly. Of note, the number of patients who suffer from aortic stenosis (AS) and mitral regurgitation (MR) is increasing in developed countries because of the aging of the populations. Transcatheter aortic valve replacement and percutaneous mitral valve repair has been widely used for AS and MR, individually. Echocardiography is the gold standard modality for initial diagnosis and subsequent evaluation of AS and MR, although the difficulties in assessing patients with these diseases still remain. Here, we review the clinical usefulness and prognostic impact of exercise echocardiography on structural heart disease, particularly on AS and MR.

  11. Small aortic valve annulus in children with fixed subaortic stenosis.

    Science.gov (United States)

    Thilenius, O G; Campbell, D; Bharati, S; Lev, M; Arcilla, R A

    1989-01-01

    Twenty-one hearts with fixed subaortic stenosis (FSAS) were examined pathologically. Thirty children with no hemodynamically significant heart disease, 31 children with valvar aortic stenosis, and 25 children with FSAS were studied by echo- and angiocardiography. The following conclusions were drawn: (1) Patients with FSAS often have abnormal aortic valve leaflets as well as small aortic valve annulus. (2) A small aortic annulus/descending aorta ratio is probably present at birth, and may decrease with increasing age. (3) In some patients with FSAS the aortic valve annulus is too small for simple resection of the fibroelastic tissue. A Konno operation is needed for these patients. (4) M-mode echocardiography has not been useful in identifying abnormally small aortic valve annulus in FSAS patients.

  12. Increased nitric oxide release and expression of endothelial and inducible nitric oxide synthases in mildly changed porcine mitral valve leaflets

    DEFF Research Database (Denmark)

    Moesgaard, Sophia Gry; Olsen, Lisbeth Høier; Viuff, Birgitte;

    2007-01-01

    Background and aim of the study: Little is known of the local role of nitric oxide (NO) in heart valves in relation to heart valve diseases. The study aim was to examine NO release and the expression of both endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase (i...

  13. Reversing blood flows act through klf2a to ensure normal valvulogenesis in the developing heart.

    Directory of Open Access Journals (Sweden)

    Julien Vermot

    2009-11-01

    Full Text Available Heart valve anomalies are some of the most common congenital heart defects, yet neither the genetic nor the epigenetic forces guiding heart valve development are well understood. When functioning normally, mature heart valves prevent intracardiac retrograde blood flow; before valves develop, there is considerable regurgitation, resulting in reversing (or oscillatory flows between the atrium and ventricle. As reversing flows are particularly strong stimuli to endothelial cells in culture, an attractive hypothesis is that heart valves form as a developmental response to retrograde blood flows through the maturing heart. Here, we exploit the relationship between oscillatory flow and heart rate to manipulate the amount of retrograde flow in the atrioventricular (AV canal before and during valvulogenesis, and find that this leads to arrested valve growth. Using this manipulation, we determined that klf2a is normally expressed in the valve precursors in response to reversing flows, and is dramatically reduced by treatments that decrease such flows. Experimentally knocking down the expression of this shear-responsive gene with morpholine antisense oligonucleotides (MOs results in dysfunctional valves. Thus, klf2a expression appears to be necessary for normal valve formation. This, together with its dependence on intracardiac hemodynamic forces, makes klf2a expression an early and reliable indicator of proper valve development. Together, these results demonstrate a critical role for reversing flows during valvulogenesis and show how relatively subtle perturbations of normal hemodynamic patterns can lead to both major alterations in gene expression and severe valve dysgenesis.

  14. Valve selection in aortic valve endocarditis

    Science.gov (United States)

    Zubrytska, Yana

    2016-01-01

    Aortic prosthetic valve endocarditis (PVE) is a potentially life-threatening disease. Mortality and incidence of infective endocarditis have been reduced in the past 30 years. Medical treatment of aortic PVE may be successful in patients who have a prompt response after antibiotic treatment and who do not have prosthetic dysfunction. In advanced stages, antibiotic therapy alone is insufficient to control the disease, and surgical intervention is necessary. Surgical treatment may be lifesaving, but it is still associated with considerable morbidity and mortality. The aim of surgery is to perform a radical excision of all infected and necrotic tissue, reconstruction of the left ventricle outflow tract, and replacement of the aortic valve. There is no unanimous consensus on which is the optimal prosthesis to implant in this context, and several surgical techniques have been suggested. We aim to analyze the efficacy of the surgical treatment and discuss the issue of valve selection in patients with aortic valve endocarditis.

  15. Carcinoid heart disease: Diagnosis and management.

    Science.gov (United States)

    Luis, Sushil A; Pellikka, Patricia A

    2016-01-01

    Hedinger syndrome refers to carcinoid valvular heart disease. The disease is believed to be triggered by vasoactive substances that result in valvular fibrosis. It classically occurs in patients with metastatic carcinoid and preferentially involves the right sided cardiac valves. Affected valves become thickened and retracted, exhibiting regurgitation and sometimes, stenosis. Echocardiography is recommended in patients with carcinoid syndrome and a follow up study is advisable in those who develop a murmur or other symptoms or signs of valvular heart disease. For appropriately selected patients, valve replacement surgery appears to improve outcomes.

  16. Heart MRI

    Science.gov (United States)

    Magnetic resonance imaging - cardiac; Magnetic resonance imaging - heart; Nuclear magnetic resonance - cardiac; NMR - cardiac; MRI of the heart; Cardiomyopathy - MRI; Heart failure - MRI; Congenital heart disease - MRI

  17. JenaValve.

    Science.gov (United States)

    Treede, Hendrik; Rastan, Ardawan; Ferrari, Markus; Ensminger, Stephan; Figulla, Hans-Reiner; Mohr, Friedrich-Wilhelm

    2012-09-01

    The JenaValve is a next-generation TAVI device which consists of a well-proven porcine root valve mounted on a low-profile nitinol stent. Feeler guided positioning and clip fixation on the diseased leaflets allow for anatomically correct implantation of the device without rapid pacing. Safety and efficacy of transapical aortic valve implantation using the JenaValve were evaluated in a multicentre prospective study that showed good short and midterm results. The valve was CE-mark released in Europe in September 2011. A post-market registry ensures on-going and prospective data collection in "real-world" patients. The transfemoral JenaValve delivery system will be evaluated in a first-in-man study in the near future. PMID:22995119

  18. Left ventricular outflow tract obstruction due to anomalous mitral valve: successful mitral valve replacement in a four month old infant.

    OpenAIRE

    Morais, P.; Westaby, S.; Hallidie-Smith, K A

    1986-01-01

    A four month old infant was investigated for heart failure was found to have mitral incompetence and severe subvalvar aortic stenosis. The left ventricular outflow tract obstruction was found to be due to an anatomically anomalous mitral valve. The obstruction could only be relieved by removal of the mitral valve and its replacement with a St Jude's prosthesis. Two years after operation the child is fit and active. There have been no difficulties with anticoagulant treatment.

  19. Transcatheter aortic valve implantation in failed bioprosthetic surgical valves

    DEFF Research Database (Denmark)

    Dvir, Danny; Webb, John G; Bleiziffer, Sabine;

    2014-01-01

    IMPORTANCE: Owing to a considerable shift toward bioprosthesis implantation rather than mechanical valves, it is expected that patients will increasingly present with degenerated bioprostheses in the next few years. Transcatheter aortic valve-in-valve implantation is a less invasive approach...... for patients with structural valve deterioration; however, a comprehensive evaluation of survival after the procedure has not yet been performed. OBJECTIVE: To determine the survival of patients after transcatheter valve-in-valve implantation inside failed surgical bioprosthetic valves. DESIGN, SETTING......, AND PARTICIPANTS: Correlates for survival were evaluated using a multinational valve-in-valve registry that included 459 patients with degenerated bioprosthetic valves undergoing valve-in-valve implantation between 2007 and May 2013 in 55 centers (mean age, 77.6 [SD, 9.8] years; 56% men; median Society of Thoracic...

  20. Sudden cardiac death and mitral and aortic valve disease

    Directory of Open Access Journals (Sweden)

    Bockeria O.L.

    2013-09-01

    Independent determinants of sudden death were left ventricular ejection fraction and atrial fibrillation. The main cause of death in patients with mitral valve stenosis is a thromboembolism from the left heart chambers to systemic circulation, and the risk of the latter increases with atrial fibrillation. There is no sudden cardiac death in mitral valve stenosis. The absence of left ventricular remodeling in mitral valve stenosis probably explains this finding. Onset of symptoms and signs of left ventricular dysfunction are the main predictors of sudden death and are indications for surgery. It should be emphasized that the database of sudden cardiac death in patients with valvular heart disease is very limited compared to patients with coronary heart disease and cardiomyopathies. Some issues related to predictors and mechanisms of SCD are currently poorly understood, therefore prevention of sudden cardiac death is difficult, especially in asymptomatic patients.

  1. Prosthetic Valve Thrombosis: Diagnosis and Management.

    Science.gov (United States)

    Garg, Jalaj; Palaniswamy, Chandrasekar; Pinnamaneni, Sowmya; Sarungbam, Judy; Jain, Diwakar

    2016-01-01

    St. Jude mechanical prosthesis is the most commonly used prosthetic device with least valvular complications with excellent hemodynamics. However, prosthetic valve thrombosis is one of the serious complications, with rates between 0.03% and 0.13% per patient-year depending on the type of anticoagulation used and compliance to the therapy. Transthoracic echocardiography (TTE) is the initial screening tool (class I) that would provide clues for the assessment of valvular hemodynamics. Fluoroscopy is an alternate imaging modality for the assessment of mechanical leaflet motion, especially in patients when prosthetic valves are difficult to image on TTE or transesophageal echocardiography. A complete fluoroscopic evaluation of a prosthetic valve includes assessment of valvular motion and structural integrity. Opening and closing angles can be measured fluoroscopically to determine whether a specific valve is functioning properly. We discuss a case of a 91-year-old man with thrombosis of bileaflet mechanical mitral prosthesis that was demonstrated on real-time fluoroscopy (not evident on TTE). An algorithmic approach to diagnosis and management of prosthetic heart valve thrombosis is outlined. PMID:25486519

  2. 脱细胞牛心包种植人血管混合细胞构建组织工程心脏瓣膜%Construction of tissue engineered heart valves based on decellularized bovine pericardium

    Institute of Scientific and Technical Information of China (English)

    成少飞; 杨岷; 陈长志; 叶清; 薛松

    2008-01-01

    Objective To evaluate the method and outcome of mixed human vascular ceils seeding on decellularized bovine pericardium in constructing a tissue engineered heart valves (TEHVs). Methods The mixed human vascular cells obtained by primary co-culture were seeded on decellularized bovine pericardium to construct a TEHVs. The morphologic and immunohistochemistry changes of the seeding cells, the ultramicrostructure of the decellularized bovine pericardium seeded with mixed human vascular cells were observed dynamically. Results The seeded cells overlaid on the deeellularized bovine pericardium gradually, and with the time-lapse, the cells stratified and penetrated into the deep layer of the pericardium. The mixed human vascular cells were verified as endothelial cells (ECs), smooth warble cells (SMC) and fibroblasts by the immunohistochemistry. And the seeding cells were testified for their ability of secreting t-PA and PAI-1 by enzyme-labeled immunosorbent assay (ELISA). The seeding cells on the pericardium were flat, lamellated or inordinate, and then stratified, with some floss and fibre. Conclusion The histocompatibility of the mixed human vascular cells and the decellularized bovine pericardium is satisfactory. The cells can grow well on the pericardium and possessed some functions of ECs.%目的 探讨在脱细胞牛心包上种植人血管混合细胞构建组织工程心脏瓣膜的方法与效果.方法 将体外培养的人血管混合细胞种植在脱细胞牛心包材料上,观察种子细胞形态学和免疫组织化学变化和牛心包超微结构变化,并测定内皮细胞分泌t-PA和PAI-1的活性.结果 种子细胞全层覆盖脱细胞牛心包表面,并浸润至组织内部生长;牛心包表面为扁平、片状、分层的细胞覆盖,细胞表面有少量绒毛和纤细的纤维结构.免疫组化显示内皮细胞Ⅷ因子、平滑肌细胞α-肌动蛋白、成纤细胞Fibronectin相关抗原呈阳性表达;种子细胞能分

  3. Finite Element Analysis of Fracture Toughness of Pyrolytic Carbon in Prosthetic Heart Valve%人工心瓣热解炭断裂韧性有限元分析

    Institute of Scientific and Technical Information of China (English)

    张建辉; 邢兴

    2012-01-01

    This article used ANSYS to conduct simulation analysis of compact tension and 3 points bending test for the isotropic pyrolytic carbon and pyrolytic carbon-coated graphite composite material used in heart valve prosthesis, calculated the plane strain fracture toughness KIC and compared the calculated results with the results of related experiments, then analyzed the effectiveness of the method that used ANSYS to calculate KIC as well as the influence of the thickness ratio of the coating and substrate and crack tip radius for the KIC of pyrolytic carbon-coated graphite composite material. Results showed that the KIC of the pure pyrolytic carbon and graphite material were respectively 1. 176 MPa √m and 1. 415 MPa √m, which were close to the results of related experiments, verifying the accuracy of using ANSYS to calculate KIC ; the KIC of composite material of pyrolytic carbon-coated graphite reduced with the increase of thickness ratio for the coating and substrate. The fracture toughness of composite material was better than that of pure pyrolytic carbon or graphite composite material when the thickness ratio of coating and substrate was on the low side; pyrolitic carbon-coated graphite had a limit notch root radius p0, which was about 5 μm, when the notch root radius p >p0, the measured value of KIC was proportional to p1/2 , and when p < po, the measured value of KIC was in line with the value of samples with sharp crack.%利用有限元分析软件ANSYS,对人工心瓣各向同性热解炭和热解炭包覆石墨复合材料进行紧凑拉伸以及三点弯曲实验仿真分析,计算材料的平面应变断裂韧性KIC,并将计算结果与相关实验结果进行对比,分析利用ANSYS计算KIC方法的有效性,以及涂层与基体厚度比、裂纹尖端半径对热解炭包覆石墨复合材料KIC值的影响.结果表明,纯热解炭和石墨材料的ANSYS计算KIC值分别为1.176 MPa√m以及1.415 MPa√m,与相关实验结果接近,验证

  4. Heimlich valve and pneumothorax

    OpenAIRE

    Gogakos, Apostolos; Barbetakis, Nikolaos; Lazaridis, George; Papaiwannou, Antonis; Karavergou, Anastasia; Lampaki, Sofia; Baka, Sofia; Mpoukovinas, Ioannis; Karavasilis, Vasilis; Kioumis, Ioannis; Pitsiou, Georgia; Katsikogiannis, Nikolaos; Tsakiridis, Kosmas; Rapti, Aggeliki; Trakada, Georgia

    2015-01-01

    The Heimlich valve is a small one-way valve used for chest drainage that empties into a flexible collection device and prevents return of gases or fluids into the pleural space. The Heimlich valve is less than 13 cm (5 inches) long and facilitates patient ambulation. Currently there are several systems in the market. It can be used in many patients instead of a traditional water seal drainage system. The Heimlich chest drainage valve was developed so that the process of draining the pleural c...

  5. 2013 update on congenital heart disease, clinical cardiology, heart failure, and heart transplant.

    Science.gov (United States)

    Subirana, M Teresa; Barón-Esquivias, Gonzalo; Manito, Nicolás; Oliver, José M; Ripoll, Tomás; Lambert, Jose Luis; Zunzunegui, José L; Bover, Ramon; García-Pinilla, José Manuel

    2014-03-01

    This article presents the most relevant developments in 2013 in 3 key areas of cardiology: congenital heart disease, clinical cardiology, and heart failure and transplant. Within the area of congenital heart disease, we reviewed contributions related to sudden death in adult congenital heart disease, the importance of specific echocardiographic parameters in assessing the systemic right ventricle, problems in patients with repaired tetralogy of Fallot and indication for pulmonary valve replacement, and confirmation of the role of specific factors in the selection of candidates for Fontan surgery. The most recent publications in clinical cardiology include a study by a European working group on correct diagnostic work-up in cardiomyopathies, studies on the cost-effectiveness of percutaneous aortic valve implantation, a consensus document on the management of type B aortic dissection, and guidelines on aortic valve and ascending aortic disease. The most noteworthy developments in heart failure and transplantation include new American guidelines on heart failure, therapeutic advances in acute heart failure (serelaxin), the management of comorbidities such as iron deficiency, risk assessment using new biomarkers, and advances in ventricular assist devices.

  6. A piezoelectrically actuated ball valve

    Science.gov (United States)

    Erwin, L. R.; Schwartz, H. W.; Teitelbaum, B. R.

    1972-01-01

    Bimorph strip composed of two layers of poled piezoelectric ceramic material closes and opens valve. Strip performs like capacitator, allowing initial inrush of current when valve is energized and then only small leakage current flows as valve remains energized.

  7. Valvular heart disease

    International Nuclear Information System (INIS)

    The predicts of the patients with valvular heart disease it has improved substantially in the last 15 years.A better understanding of the appropriate programming of the surgery it is one of the key reasons .In general the surgery for the illness valvular stenosis it can take a long time until the appearance of the symptoms. Probably that in the future it progresses toward a conservation of the native valves in the patient.It will be beneficial because the valves modern prosthetic even have inherent risks .The aortic stenosis acquired it will follow requiring a valve prosthetic substitution .But the valvular disease it will be treated every time but by means of procedures that keep the native valves.They include the lung autograft for the aortic stenosis ,The balloonla commissurectomy with ball for the mitral stenosis ,the aortic valvular repair for aortic inadequacy .This procedures will make that the surgery is but attractive eliminating the risks associated with the prosthetics.The continuous advances in the valuation non invasive of the aortic and mitral valves, the of the appropriate selection moment for the derivation for surgical treatment, the improves of the surgical techniques for the valvular substitution and reconstruction and the very recent advances in less aggressive surgical focuses they should combine to improve the patients' perspectives with cardiopatia valvular

  8. A Comparative In Vitro Study of the Flow Characteristics Distal to Mechanical and Natural Mitral Valves

    OpenAIRE

    Mace, Amber

    2002-01-01

    Mechanical heart valve (MHV) flows are characterized by high shear stress, regions of recirculation, and high levels of turbulent fluctuations. It is well known that these flow conditions are hostile to blood constituents, which could lead to thromboembolism. In the ongoing effort to reduce long-term complications and morbidity, it is imperative that we better understand the flow characteristics of the natural valve as well as that of the mechanical valve. In this study, we overcome many o...

  9. Blood Flow Simulations for the Design of Stented Valve Reducer in Enlarged Ventricular Outflow Tracts

    OpenAIRE

    Caiazzo, Alfonso; Guibert, Romain; Boudjemline, Younes; Vignon-Clementel, Irene

    2015-01-01

    International audience Tetralogy of Fallot is a congenital heart disease characterized over time, after the initial repair, by the absence of a functioning pulmonary valve, which causes regurgitation, and by progressive enlargement of the right ventricle outflow tract (RVOT). Due to this pathological anatomy, available transcatheter valves are usually too small to be deployed there. To avoid surgical valve replacement, an alternative consists in implanting a reducer prior to or in combinat...

  10. Heimlich valve and pneumothorax.

    Science.gov (United States)

    Gogakos, Apostolos; Barbetakis, Nikolaos; Lazaridis, George; Papaiwannou, Antonis; Karavergou, Anastasia; Lampaki, Sofia; Baka, Sofia; Mpoukovinas, Ioannis; Karavasilis, Vasilis; Kioumis, Ioannis; Pitsiou, Georgia; Katsikogiannis, Nikolaos; Tsakiridis, Kosmas; Rapti, Aggeliki; Trakada, Georgia; Zissimopoulos, Athanasios; Tsirgogianni, Katerina; Zarogoulidis, Konstantinos; Zarogoulidis, Paul

    2015-03-01

    The Heimlich valve is a small one-way valve used for chest drainage that empties into a flexible collection device and prevents return of gases or fluids into the pleural space. The Heimlich valve is less than 13 cm (5 inches) long and facilitates patient ambulation. Currently there are several systems in the market. It can be used in many patients instead of a traditional water seal drainage system. The Heimlich chest drainage valve was developed so that the process of draining the pleural cavity could be accomplished in a safe, relatively simple, and efficient manner. This valve system has replaced the cumbersome underwater drainage bottle system. Moreover; the Heimlich valve system connects to chest tubing and allows fluid and air to pass in one direction only. This system functions in any position, and it does not ever need to be clamped, a regulated suction can be attached to it if necessary. The valve drains into a plastic bag that can be held at any level, allowing the patient undergoing chest drainage to be ambulatory simply by carrying the bag. In the current mini review we will present the Heimlich valve system and method of insertion. PMID:25861609

  11. Shutoff and throttling valve

    Science.gov (United States)

    Hays, L. G.

    1974-01-01

    Leaktight shutoff, precise flow control, and very low pressure drop are incorporated in all-metal valve designed for operation under extreme temperatures. Valve constructed with refractory metal is intended for control of high-temperature liquid cesium, but has applications related to control of high- and low-temperature liquids and gases.

  12. Heart Disease

    Science.gov (United States)

    ... Got Homework? Here's Help White House Lunch Recipes Heart Disease KidsHealth > For Kids > Heart Disease Print A A ... chest pain, heart attacks, and strokes . What Is Heart Disease? The heart is the center of the cardiovascular ...

  13. Impact Fatigue Characteristics of Valve Leaves for Small Hermetic Reciprocating Compressors

    NARCIS (Netherlands)

    Altunlu, A. Can; Lazoglu, Ismail; Oguz, Emre; Kara, Serkan

    2010-01-01

    This paper presents an investigation on the impact fatigue characteristics of valve leaves that are prevalently used in hermetic reciprocating compressors especially for the household type refrigerators. The investigation relates the impact fatigue lifetime of the valve leaves that is the heart of t

  14. The role of pygopus in the differentiation of intracardiac valves in Drosophila.

    Science.gov (United States)

    Tang, Min; Yuan, Wuzhou; Bodmer, Rolf; Wu, Xiushan; Ocorr, Karen

    2014-01-01

    Cardiac valves serve an important function; they support unidirectional blood flow and prevent blood regurgitation. Wnt signaling plays an important role in the formation of mouse cardiac valves and cardiac valve proliferation in Zebrafish, but identification of the specific signaling components involved has not been addressed systematically. Of the components involved in Wnt signal transduction, pygopus (pygo), first identified as a core component of Wnt signaling in Drosophila, has not yet to be investigated with respect to valve development and differentiation. Here, we take advantage of the Drosophila heart model to study the role of pygo in formation of valves between the cardiac chambers. We found that cardiac-specific pygo knockdown in the Drosophila heart causes dilation in the region of these cardiac valves, and their characteristic dense mesh of myofibrils does not form and resembles that of neighboring cardiomyocytes. In contrast, heart-specific knockdown of the transcription factors, arm/β-Cat, lgs/BCL9, or pan/TCF, which mediates canonical Wnt signal transduction, shows a much weaker valve differentiation defect. Double-heterozygous combinations of mutants for pygo and the Wnt-signaling components have no additional effect on heart function compared with pygo heterozygotes alone. These results are consistent with the idea that pygo functions independently of canonical Wnt signaling in the differentiation of the adult interchamber cardiac valves.

  15. Multidetector-row computed tomography imaging characteristics of mechanical prosthetic valves

    NARCIS (Netherlands)

    Symersky, P.; Budde, R.P.; Prokop, M.; Mol, B.A. de

    2011-01-01

    BACKGROUND AND AIM OF THE STUDY: Electrocardiogram-gated multidetector-row computed tomography (MDCT) imaging may aid in the evaluation of prosthetic valve dysfunction. A pulsatile in vitro model was developed to study the MDCT imaging characteristics of mechanical heart valves (MHVs). METHODS: Bjor

  16. Multidetector-Row Computed Tomography Imaging Characteristics of Mechanical Prosthetic Valves

    NARCIS (Netherlands)

    Symersky, Petr; Budde, Ricardo P. J.; Prokop, Mathias; de Mol, Bas A. J. M.

    2011-01-01

    Background and aim of the study: Electrocardiogram-gated multidetector-row computed tomography (MDCT) imaging may aid in the evaluation of prosthetic valve dysfunction. A pulsatile in vitro model was developed to study the MDCT imaging characteristics of mechanical heart valves (MHVs). Methods: Bjor

  17. Aortic Valve Replacement for Infective Endocarditis in a Renal Transplant Recipient

    OpenAIRE

    Masmoudi Sayda; Frikha Imed; Trigui Walid; Karoui Abdelhamid; Daoud Moncef; Sahnoun Youssef

    2000-01-01

    Renal transplant recipients are more prone to developing infections. We report a 37-year old renal transplant recipient who developed infective endocarditis of the aortic valve, heart failure and renal allograft dysfunction. He underwent aortic valve replacement which was followed by improvement in cardiac as well as allograft function.

  18. Aortic Valve Replacement for Infective Endocarditis in a Renal Transplant Recipient

    Directory of Open Access Journals (Sweden)

    Masmoudi Sayda

    2000-01-01

    Full Text Available Renal transplant recipients are more prone to developing infections. We report a 37-year old renal transplant recipient who developed infective endocarditis of the aortic valve, heart failure and renal allograft dysfunction. He underwent aortic valve replacement which was followed by improvement in cardiac as well as allograft function.

  19. Anticoagulation for Prosthetic Valves

    Directory of Open Access Journals (Sweden)

    Tsuyoshi Kaneko

    2013-01-01

    Full Text Available Implantation of prosthetic valve requires consideration for anticoagulation. The current guideline recommends warfarin on all mechanical valves. Dabigatran is the new generation anticoagulation medication which is taken orally and does not require frequent monitoring. This drug is approved for treatment for atrial fibrillation and venous thromboembolism, but the latest large trial showed that this drug increases adverse events when used for mechanical valve anticoagulation. On-X valve is the new generation mechanical valve which is considered to require less anticoagulation due to its flow dynamics. The latest study showed that lower anticoagulation level lowers the incidence of bleeding, while the risk of thromboembolism and thrombosis remained the same. Anticoagulation poses dilemma in cases such as pregnancy and major bleeding event. During pregnancy, warfarin can be continued throughout pregnancy and switched to heparin derivative during 6–12 weeks and >36 weeks of gestation. Warfarin can be safely started after 1-2 weeks of discontinuation following major bleeding episode.

  20. Cardiac sarcoidosis and heart transplantation: a report of four consecutive patients

    DEFF Research Database (Denmark)

    Milman, N.; Andersen, Claus Bøgelund; Mortensen, Sven Aage;

    2008-01-01

    to HTx. In three patients, all with dilated cardiomyopathy due to myocardial sarcoidosis, the final diagnosis was obtained by examination of the explanted heart. Arrythmias (supraventricular and ventricular), heart block, mitral valve insufficiency and dilated cardiomyopathy were prominent clinical...

  1. Heart disease in patients with osteogenesis imperfecta

    DEFF Research Database (Denmark)

    Ashournia, Hamoun; Johansen, Frank Ted; Folkestad, Lars;

    2015-01-01

    described, less is known about the effects of decreased collagen on other organs. In the heart, collagen type 1 is present in the heart valves, chordae tendineae, annuli fibrosi and the interventricular septum. It is thus likely that the heart is affected in OI. OBJECTIVES: The aim of this systematic...... commonly reported heart diseases amongst the patients with OI were valvulopathies and increased aortic diameter. Findings in the large case series and the cross-sectional studies were broadly similar to each other. CONCLUSION: The findings support the hypothesis that patients with OI have increased risk of...... heart disease compared to healthy controls. It is biologically plausible that patients with OI may have an increased risk of developing heart disease, and valve disease in particular....

  2. Computational valve plate design

    Science.gov (United States)

    Kalbfleisch, Paul

    Axial piston machines are widely used in many industries for their designs compactness, flexibility in power transfer, variable flow rate, and high efficiencies as compared to their manufacturing costs. One important component of all axial piston machines that is a very influential on the performance of the unit is the valve plate. The aim of this research is to develop a design methodology that is general enough to design all types of valve plates and the simple enough not to require advanced technical knowledge from the user. A new style of valve plate designs has been developed that comprehensively considers all previous design techniques and does not require significant changes to the manufacturing processes of valve plates. The design methodology utilizes a previously developed accurate computer model of the physical phenomenon. This allows the precise optimization of the valve plate design through the use of simulations rather than expensive trial and error processes. The design of the valve plate is clarified into the form of an optimization problem. This formulation into an optimization problem has motivated the selection of an optimization algorithm that satisfies the requirements of the design. The proposed design methodology was successfully tested in a case study in the shown to be very successful in improving required performance of the valve plate design.

  3. Gate valve performance prediction

    International Nuclear Information System (INIS)

    The Electric Power Research Institute is carrying out a program to improve the performance prediction methods for motor-operated valves. As part of this program, an analytical method to predict the stem thrust required to stroke a gate valve has been developed and has been assessed against data from gate valve tests. The method accounts for the loads applied to the disc by fluid flow and for the detailed mechanical interaction of the stem, disc, guides, and seats. To support development of the method, two separate-effects test programs were carried out. One test program determined friction coefficients for contacts between gate valve parts by using material specimens in controlled environments. The other test program investigated the interaction of the stem, disc, guides, and seat using a special fixture with full-sized gate valve parts. The method has been assessed against flow-loop and in-plant test data. These tests include valve sizes from 3 to 18 in. and cover a considerable range of flow, temperature, and differential pressure. Stem thrust predictions for the method bound measured results. In some cases, the bounding predictions are substantially higher than the stem loads required for valve operation, as a result of the bounding nature of the friction coefficients in the method

  4. A Novel Technique for Experimental Flow Visualization of Mechanical Valves.

    Science.gov (United States)

    Huang Zhang, Pablo S; Dalal, Alex R; Kresh, J Yasha; Laub, Glenn W

    2016-01-01

    The geometry of the hinge region in mechanical heart valves has been postulated to play an important role in the development of thromboembolic events (TEs). This study describes a novel technique developed to visualize washout characteristics in mechanical valve hinge areas. A dairy-based colloidal suspension (DBCS) was used as a high-contrast tracer. It was introduced directly into the hinge-containing sections of two commercially available valves mounted in laser-milled fluidic channels and subsequently washed out at several flow rates. Time-lapse images were analyzed to determine the average washout rate and generate intensity topography maps of the DBCS clearance. As flow increased, washout improved and clearance times were shorter in all cases. Significantly different washout rate time constants were observed between valves, average >40% faster clearance (p < 0.01). The topographic maps revealed that each valve had a characteristic pattern of washout. The technique proved reproducible with a maximum recorded standard error of mean (SEM) of ±3.9. Although the experimental washout dynamics have yet to be correlated with in vivo visualization studies, the methodology may help identify key flow features influencing TEs. This visualization methodology can be a useful tool to help evaluate stagnation zones in new and existing heart valve hinge designs. PMID:26554553

  5. Culturing Mouse Cardiac Valves in the Miniature Tissue Culture System.

    Science.gov (United States)

    Kruithof, Boudewijn P T; Lieber, Samuel C; Kruithof-de Julio, Marianna; Gaussin, Vincian; Goumans, Marie José

    2015-01-01

    Heart valve disease is a major burden in the Western world and no effective treatment is available. This is mainly due to a lack of knowledge of the molecular, cellular and mechanical mechanisms underlying the maintenance and/or loss of the valvular structure. Current models used to study valvular biology include in vitro cultures of valvular endothelial and interstitial cells. Although, in vitro culturing models provide both cellular and molecular mechanisms, the mechanisms involved in the 3D-organization of the valve remain unclear. While in vivo models have provided insight into the molecular mechanisms underlying valvular development, insight into adult valvular biology is still elusive. In order to be able to study the regulation of the valvular 3D-organization on tissue, cellular and molecular levels, we have developed the Miniature Tissue Culture System. In this ex vivo flow model the mitral or the aortic valve is cultured in its natural position in the heart. The natural configuration and composition of the leaflet are maintained allowing the most natural response of the valvular cells to stimuli. The valves remain viable and are responsive to changing environmental conditions. This MTCS may provide advantages on studying questions including but not limited to, how does the 3D organization affect valvular biology, what factors affect 3D organization of the valve, and which network of signaling pathways regulates the 3D organization of the valve. PMID:26555276

  6. Mitral valve repair in a patient with mesocardia.

    Science.gov (United States)

    Morisaki, Akimasa; Hattori, Koji; Motoki, Manabu; Takahashi, Yosuke; Nishimura, Shinsuke; Shibata, Toshihiko

    2014-01-01

    A 75-year-old man was referred for treatment of mitral valve prolapse secondary to tendon rupture. He had been receiving oral and inhaled corticosteroids for bronchial asthma and bronchial ectasia. Chest X-ray showed cardiomegaly with protrusion of the right atrium shadow. Computed tomography revealed dislocation and counterclockwise rotation of the heart with the apex of the heart located in the mid-thorax, indicating mesocardia. We believed that it would have been difficult to expose the mitral valve through a right-sided left atrial approach. Thus, we planned to perform mitral valve repair via a trans-septal approach. The right thoracotomy approach was not suitable because of respiratory dysfunction. After a median sternotomy, the left anterior descending coronary artery was identified just beneath the midline of the sternum. Even after decompression of the heart under cardiopulmonary bypass, we could not obtain a good view of the right side of the left atrium. By a transseptal approach with a self-retaining retractor and atrial hooks, we obtained adequate exposure of the mitral valve and performed the mitral valve repair uneventfully.

  7. Danfos: Thermostatic Radiator Valves

    DEFF Research Database (Denmark)

    Gregersen, Niels; Oliver, James; Hjorth, Poul G.

    2000-01-01

    This problem deals with modelling the flow through a typical Danfoss thermostatic radiator valve.Danfoss is able to employ Computational Fluid Dynamics (CFD) in calculations of the capacity of valves, but an experienced engineer can often by rules of thumb "guess" the capacity, with a precision...... similar to the one achieved by the expensive and time-consuming CFD calculations. So CFD is only used in case of entirely new designs or where a very detailed knowledge of the flow is required. Even though rules of thumb are useful for those, who have developed them, Danfoss needs an objective and general...... method that can be used to predict the performance of valves....

  8. Prosthetic valve endocarditis with valvular obstruction after transcatheter aortic valve replacement.

    Science.gov (United States)

    Pabilona, Christine; Gitler, Bernard; Lederman, Jeffrey A; Miller, Donald; Keltz, Theodore N

    2015-04-01

    Patients with severe aortic stenosis who are at high risk for open-heart surgery might be candidates for transcatheter aortic valve replacement (TAVR). To our knowledge, this is the first report of Streptococcus viridans endocarditis that caused prosthetic valve obstruction after TAVR. A 77-year-old man who had undergone TAVR 17 months earlier was admitted because of evidence of prosthetic valve endocarditis. A transthoracic echocardiogram revealed a substantial increase in the transvalvular peak gradient and mean gradient in comparison with an echocardiogram of 7 months earlier. A transesophageal echocardiogram showed a 1.5-cm vegetation obstructing the valve. Blood cultures yielded penicillin-sensitive S. viridans. The patient was hemodynamically stable and was initially treated with vancomycin because of his previous penicillin allergy. Subsequent therapy with levofloxacin, oral penicillin (after a negative penicillin skin test), and intravenous penicillin eliminated the symptoms of the infection. Transcatheter aortic valve replacement is a relatively new procedure, and sequelae are still being discovered. We recommend that physicians consider obstructive endocarditis as one of these.

  9. Aortic regurgitation after transcatheter aortic valve replacement.

    Science.gov (United States)

    Werner, Nikos; Sinning, Jan-Malte

    2014-01-01

    Paravalvular aortic regurgitation (AR) negatively affects prognosis following transcatheter aortic valve replacement (TAVR). As transcatheter heart valves (THV) are anchored using a certain degree of oversizing at the level of the aortic annulus, incomplete stent frame expansion because of heavily annular calcifications, suboptimal placement of the prosthesis, and/or annulus-prosthesis size-mismatch can contribute to paravalvular AR with subsequent increased mortality risk. Echocardiography is essential to differentiate between transvalvular and paravalvular AR and to further elucidate the etiology of AR during the procedure. However, because echocardiographic quantification of AR in TAVR patients remains challenging, especially in the implantation situation, a multimodal approach to the evaluation of AR with use of hemodynamic measurements and imaging modalities is useful to precisely quantify the severity of AR immediately after valve deployment. "Next-generation" THVs are already on the market and first results show that paravalvular AR related to design modifications (eg, paravalvular space-fillers, full repositionability) are rarely seen in these valve types.  PMID:24632758

  10. Aortic valve surgery: what is the future?

    Science.gov (United States)

    Hudorović, Narcis

    2008-04-01

    Modern surgical treatment for aortic valve disease has undergone significant improvements in all areas of this procedure. Successful treatment strategies for cardiovascular diseases have often been initiated and driven by surgeons. Radical excision of diseased tissue, repair and replacement strategies lead to long-term successful treatment of the underlying diseases and clearly improved patient outcome. In highly developed nations, valve surgery will be increasing applied in older people, with more co-morbidities and a higher incidence of concomitant coronary artery disease. Cardiovascular surgeons will be facing increased competition from the catheter-based procedures; these are already applied clinically, and their numbers will rise in near future. Right now interventional cardiologists supported by some cardiac surgeons are on their way to transform some conventional open surgical procedures into catheter-based less invasive interventions, such as valve repair and replacement. Cardiovascular surgery is undergoing a rapid transformation; socio-economic factors and recent advances in medical technology contribute to these changes. Further developments will come, and surgeons with all their expertise in the treatment of valvular heart disease need to be part of it. Cardiovascular surgeons have to adapt the exciting new approaches of transapical and transfemoral transcatheter valve implantation techniques. PMID:17573248

  11. Surgical treatment of tricuspid regurgitation after mitral valve surgery: a retrospective study in China

    Directory of Open Access Journals (Sweden)

    Li Zong-Xiao

    2012-04-01

    Full Text Available Abstract Background Functional tricuspid regurgitation (TR occurs in patients with rheumatic mitral valve disease even after mitral valve surgery. The aim of this study was to analyze surgical results of TR after previous successful mitral valve surgery. Methods From September 1996 to September 2008, 45 patients with TR after previous mitral valve replacement underwent second operation for TR. In those, 43 patients (95.6% had right heart failure symptoms (edema of lower extremities, ascites, hepatic congestion, etc. and 40 patients (88.9% had atrial fibrillation. Twenty-six patients (57.8% were in New York Heart Association (NYHA functional class III, and 19 (42.2% in class IV. Previous operations included: 41 for mechanical mitral valve replacement (91.1%, 4 for bioprosthetic mitral valve replacement (8.9%, and 7 for tricuspid annuloplasty (15.6%. Results The tricuspid valves were repaired with Kay's (7 cases, 15.6% or De Vega technique (4 cases, 8.9%. Tricuspid valve replacement was performed in 34 cases (75.6%. One patient (2.2% died. Postoperative low cardiac output (LCO occurred in 5 patients and treated successfully. Postoperative echocardiography showed obvious reduction of right atrium and ventricle. The anterioposterior diameter of the right ventricle decreased to 25.5 ± 7.1 mm from 33.7 ± 6.2 mm preoperatively (P Conclusion TR after mitral valve replacement in rheumatic heart disease is a serious clinical problem. If it occurs or progresses late after mitral valve surgery, tricuspid valve annuloplasty or replacement may be performed with satisfactory results. Due to the serious consequence of untreated TR, aggressive treatment of existing TR during mitral valve surgery is recommended.

  12. 合并重度肺动脉高压瓣膜病患者行机械瓣膜置换的围术期治疗%Perioperative management of mechanical valve replacement in patients with valvular heart diseases complicated by severe pulmonary artery hypertension

    Institute of Scientific and Technical Information of China (English)

    刘湘君; 景小勇; 李洪银; 潘广玉; 吴清玉

    2011-01-01

    Objective To summarize the perioperative management of mechanical valve replacement in patients with valvular heart diseases complicated by severe pulmonary artery hypertension. Methods The clinical data of 41 patients with valvular heart diseases complicated by severe pulmonary artery hypertension( PASP > 70mmHg ) performed mechanical valve replacement recently in the hospital were analyzed. Among 21 of them were cases with MVR ( mitral valve replacement, 19 cases of rheaumatic diseases, 2 cases of prolapse ), 4 cases with AVR ( aortic valve replacement, 3 cases of rheumatic diseases,1 case of bicuspid aortic valve ) and 16 cases with MVR + AVR ( all rheumatic heart diseases ). 27 cases with De Vega TVP ( tricuspid valvuloplasty ), 3 cases with coronary artery bypass grafting, and 6 cases with left atrial thrombectomy were performed concomitantly. Echocardiography was employed to evaluate the operation effect and preoperative, intraoperative and postoperative care were reviewed. Results Two of 41 cases were death ( 4.9% ), 2 cases of renal failure ( 4.9% ) in perio perative stage. The average pulmonary artery pressure dropped significantly 1 week after surgery( 91 mmHg ± 19 mmHg vs 37 mmHg ± 10 mmHg ), then dropped to ( 35 ± 13 )mmHg at 3 months later. All of the patients recovered to NYHA function class Ⅰ ~ Ⅱ at 3 months later. Conclusion Valve replacement significantly decreased the pulmonary artery pressure of valve diseases and improved cardiac function of valvulopathy patients. On the precondition of complete pre-operation preparation, appropriate operation scheme, prevention and treatment of post-operation complication, severe pulmonary artery hypertension did not increase the mortality rate of mechanical valve replacement.%目的 总结分析瓣膜病合并重度肺动脉高压患者行机械瓣膜置换术的围术期治疗经验.方法 分析瓣膜病合并重度肺动脉高压(肺动脉收缩压>70 mmHg)的机械瓣膜置换术患者41

  13. Infections in open heart surgery.

    Science.gov (United States)

    Baddour, L M; Kluge, R M

    1989-01-01

    More than 250,000 open heart surgical procedures are performed annually in the United States. The majority of these procedures are coronary artery bypass grafts (CABG) and valve replacements. In this forum our authors discuss the kinds of infections that occur in patients following open heart surgery, as well as the documented risk factors and microbiology of these infections. We also asked each author to outline the criteria used to diagnose post open heart surgery infections, and to address associated consequences and complications. Finally, we were interested in each author's definition of the infection control practitioner's role in the prevention of this particular subset of nosocomial infections.

  14. Complete Transversal Disc Fracture in a Björk-Shiley Delrin Mitral Valve Prosthesis 43 Years After Implantation.

    Science.gov (United States)

    González-Santos, Jose María; Arnáiz-García, María Elena; Dalmau-Sorlí, María José; Sastre-Rincón, Jose Alfonso; Hernández-Hernández, Jesús; Pérez-Losada, María Elena; Sagredo-Meneses, Víctor; López-Rodríguez, Javier

    2016-10-01

    A patient who underwent previous implantation of a mitral valve replacement with a Björk-Shiley Delrin (BSD) mitral valve prosthesis during infancy was admitted to our institution 43 years later after an episode of syncope and cardiac arrest. Under extreme hemodynamic instability, a mitral valve prosthetic dysfunction causing massive mitral regurgitation was identified. The patient underwent an emergent cardiac operation, and a complete disc fracture with partial disc migration was found. Exceptional cases of mechanical prosthetic heart valve fracture exist. We report the first case of complete transversal disc rupture of a BSD mitral valve prosthesis after the longest period of implantation ever reported in that position. PMID:27645963

  15. Nitric oxide synthase-3 promotes embryonic development of atrioventricular valves.

    Science.gov (United States)

    Liu, Yin; Lu, Xiangru; Xiang, Fu-Li; Lu, Man; Feng, Qingping

    2013-01-01

    Nitric oxide synthase-3 (NOS3) has recently been shown to promote endothelial-to-mesenchymal transition (EndMT) in the developing atrioventricular (AV) canal. The present study was aimed to investigate the role of NOS3 in embryonic development of AV valves. We hypothesized that NOS3 promotes embryonic development of AV valves via EndMT. To test this hypothesis, morphological and functional analysis of AV valves were performed in wild-type (WT) and NOS3(-/-) mice at postnatal day 0. Our data show that the overall size and length of mitral and tricuspid valves were decreased in NOS3(-/-) compared with WT mice. Echocardiographic assessment showed significant regurgitation of mitral and tricuspid valves during systole in NOS3(-/-) mice. These phenotypes were all rescued by cardiac specific NOS3 overexpression. To assess EndMT, immunostaining of Snail1 was performed in the embryonic heart. Both total mesenchymal and Snail1(+) cells in the AV cushion were decreased in NOS3(-/-) compared with WT mice at E10.5 and E12.5, which was completely restored by cardiac specific NOS3 overexpression. In cultured embryonic hearts, NOS3 promoted transforming growth factor (TGFβ), bone morphogenetic protein (BMP2) and Snail1expression through cGMP. Furthermore, mesenchymal cell formation and migration from cultured AV cushion explants were decreased in the NOS3(-/-) compared with WT mice. We conclude that NOS3 promotes AV valve formation during embryonic heart development and deficiency in NOS3 results in AV valve insufficiency.

  16. Aortic valve replacement

    DEFF Research Database (Denmark)

    Kapetanakis, Emmanouil I; Athanasiou, Thanos; Mestres, Carlos A;

    2008-01-01

    BACKGROUND AND AIMS OF THE STUDY: Prompted by anecdotal evidence and observations by surgeons, an investigation was undertaken into the potential differences in implanted aortic valve prosthesis sizes, during aortic valve replacement (AVR) procedures, between northern and southern European...... countries. METHODS: A multi-institutional, non-randomized, retrospective analysis was conducted among 2,932 patients who underwent AVR surgery at seven tertiary cardiac surgery centers throughout Europe. Demographic and perioperative variables including valve size and type, body surface area (BSA) and early......: Prostheses with diameter valve size was also smaller in southern compared to northern European patients (21.6 +/- 2.1 mm versus 23.4 +/- 2.2 mm, p

  17. Congenital quadricuspid aortic valve: analysis of 11 surgical cases

    Institute of Scientific and Technical Information of China (English)

    TANG Yang-feng; XU Ji-bin; HAN Lin; LU Fang-lin; LANG Xi-long; SONG Zhi-gang; XU Zhi-yun

    2011-01-01

    Background Congenital quadricuspid aortic valve is rarely seen during aortic valve replacement (AVR).The diagnosis and treatment of the disease were reported in 11 cases.Methods Eleven patients (nine men and two women,mean age 33.4 years) with quadricuspid aortic valve were retrospectively evaluated.Medical records,echocardiograms and surgical treatment were reviewed.Results In accordance with the Hurwitz and Roberts classification,the patients were classified as type A (n=2),type B (n=7),type F (n=1) and type G (n=1).Three patients were associated with other heart diseases,including infective endocarditis and mitral prolaps,left superior vena cava,aortic aneurysm.All had aortic regurgitation (AR) except two with aortic stenosis (AS),detected by color-flow Doppler echocardiography.The congenital quadricuspid aortic valve deformity in seven patients was diagnosed by echocardiography.All patients underwent successful aortic valve replacement.Conclusion Quadricuspid aortic valve is a rare cause of aortic insufficiency,while echocardiography plays an important role in diagnosing the disease.Aortic valve replacement is the major therapy for the disease.

  18. When a Mechanical Valve Goes Freestyle: A Patient Tailored Valve-In-Valve Implantation.

    Science.gov (United States)

    François, J; Cathenis, K; Hamerlijnck, R

    2015-01-01

    In case of a redo operation after a full root replacement there are two possible options: replacing the entire root or performing a more conservative valve-in-valve implantation. Regarding the relatively high morbidity and mortality of a redo root replacement, the valve-in-valve implantation is the preferred choice if technically feasible. We present the case of a valve-in-valve implantation with a St. Jude mechanical valve in a Medtronic bioprosthesis in a 57-year old man. Follow-up echocardiography after 1 month showed a mean gradient of 17 mmHg and no paravalvular leakage. The combination of a St. Jude bileaflet mechanical valve implanted in a Freestyle root prosthesis has not been described. This case shows that patient tailored treatment with a St. Jude bileaflet mechanical valve in a Freestyle aortic root valve can be safely performed and might be the preferred choice for younger patients, if technically feasible. PMID:26560005

  19. Antiphospholipid Syndrome and Libman-Sacks Endocarditis in a Bioprosthetic Mitral Valve.

    Science.gov (United States)

    Sladek, Eric H; Accola, Kevin D

    2016-02-01

    This report describes one the first cases of antiphospholipid syndrome and Libman-Sacks endocarditis in a bioprosthetic valve. A redo mitral valve replacement was carried out owing to early deterioration of the prior valve. Initially it was considered secondary to rheumatic heart disease; however, pathology analysis and autoimmune workup revealed antiphospholipid syndrome with Libman-Sacks endocarditis. We believe certain populations with mitral valve stenosis may have an underlying antiphospholipid syndrome. As a result, there needs to be a lower threshold for identifying this disease.

  20. Left-sided approach for mitral valve replacement in a case of dextrocardia with situs solitus.

    Science.gov (United States)

    Kikon, Mhonchan; Kazmi, Aamir; Gupta, Anubhav; Grover, Vijay

    2013-11-01

    Mitral valve surgery in dextrocardia is technically challenging due to its anatomical malposition. Minor modifications are required in the surgical technique to counteract the problems during cannulation and exposure of the mitral valve. We report a case of a patient with dextrocardia, situs solitus, rheumatic heart disease, severe mitral regurgitation, moderate pulmonary artery hypertension, and severe left ventricular dysfunction who underwent mitral valve replacement using a two-stage right atrial cannulation with left-sided left atrial atriotomy, with the surgeon standing on the left side of the patient. Our approach for mitral valve surgery in this clinical setting is simple.

  1. Factors affecting computed tomography image quality for assessment of mechanical aortic valves.

    Science.gov (United States)

    Suh, Young Joo; Kim, Young Jin; Hong, Yoo Jin; Lee, Hye-Jeong; Hur, Jin; Hong, Sae Rom; Im, Dong Jin; Kim, Yun Jung; Choi, Byoung Wook

    2016-06-01

    Evaluating mechanical valves with computed tomography (CT) can be problematic because artifacts from the metallic components of valves can hamper image quality. The purpose of this study was to determine factors affecting the image quality of cardiac CT to improve assessment of mechanical aortic valves. A total of 144 patients who underwent aortic valve replacement with mechanical valves (ten different types) and who underwent cardiac CT were included. Using a four-point grading system, the image quality of the CT scans was assessed for visibility of the valve leaflets and the subvalvular regions. Data regarding the type of mechanical valve, tube voltage, average heart rate (HR), and HR variability during CT scanning were compared between the non-diagnostic (overall image quality score ≤2) and diagnostic (overall image quality score >2) image quality groups. Logistic regression analyses were performed to identify predictors of non-diagnostic image quality. The percentage of valve types that incorporated a cobalt-chrome component (two types in total) and HR variability were significantly higher in the non-diagnostic image group than in the diagnostic group (P  0.05). Valve type was the only independent predictor of non-diagnostic quality. The CT image quality for patients with mechanical aortic valves differed significantly depending on the type of mechanical valve used and on the degree of HR variability.

  2. Percutaneous Valve Replacement: Significance of Different Delivery Systems In Vitro and In Vivo

    International Nuclear Information System (INIS)

    Background and purpose. Percutaneous heart valve replacement is an exciting growing field in cardiovascular medicine yet still with some major problems. Only sophisticated improvement of the instruments could make it a real alternative to conventional surgery. Therefore, the aim of this study was to evaluate different delivery devices for percutaneous heart valve replacement in vitro and in vivo. Methods. A catheter prototype designed by our group, and two commercially available devices for the delivery of esophageal stents and aortic endoprostheses, were tested. After in vitro experiments, an ovine animal model of transfemoral pulmonary valve implantation was established using biological valved self-expanding stents. Only the delivery device for aortic endografts (Medtronic, Talent, Santa Rosa, CA, USA) allowed fast in vitro procedures without material fatigue. This device was chosen for the in vivo tests. Results. Technical success was achieved in 9 of 10 animals (90%). One animal died after perforation of the ventricular wall. Orthotopic pulmonary placement was performed in 6 animals and intentional supravalvular valved stent placement in 3 animals. Conclusions. An adequate in vitro model for this evolving field of interventional heart valve replacement is presented. Furthermore, the present study pinpoints the key characteristics that are mandatory for a delivery system in percutaneous pulmonary valve implantation. With regard to the delivery device's ductility observed during this 'venous' study, an approach to transfemoral aortic valve implantation seems feasible

  3. Heart Transplant

    Science.gov (United States)

    ... 2015 A heart transplant gives a patient with congenital heart disease the opportunity to have a normal heart with ... pulmonary artery and left atrium. In patients with congenital heart disease, the surgeon may simultaneous transplant the lungs and ...

  4. Heart Block

    Science.gov (United States)

    ... the signal causes the heart to contract and pump blood. Heart block occurs if the electrical signal is ... degree heart block limits the heart's ability to pump blood to the rest of the body. This type ...

  5. Recognizing Advanced Heart Failure and Knowing Your Options

    Science.gov (United States)

    ... different procedures for different types of valve defects. Percutaneous coronary intervention: A blocked heart artery can be opened using ... placed in the artery to keep it open. Percutaneous coronary intervention, or PCI, is also known as coronary angioplasty. ...

  6. Valvular heart disease in antiphospholipid syndrome.

    Science.gov (United States)

    Zuily, Stéphane; Huttin, Olivier; Mohamed, Shirine; Marie, Pierre-Yves; Selton-Suty, Christine; Wahl, Denis

    2013-04-01

    Heart valve disease (HVD) is the most frequent cardiac manifestation in patients with antiphospholipid syndrome (APS), with prevalence of 30 %. The definition is based on the presence of thickening or vegetation of the valves (mainly mitral and aortic) as described by Libman and Sacks for patients with systemic lupus erythematosus (SLE). Transthoracic and/or transoesophageal echocardiography (TTE and TEE, respectively) enable early and accurate diagnosis and help avoid misdiagnosis as rheumatic valve disease. The presence of antiphospholipid antibodies (aPL) in SLE patients is associated with a threefold greater risk of HVD, confirming the crucial importance of these antibodies in the pathogenic process, leading to thrombotic manifestations on valves because of hypercoagulability. Natural history is characterized by worsening of HVD over time with an increased risk for stroke. APS patients undergoing valve-replacement surgery are at high risk of thrombotic and bleeding complications. Thus aPL-associated HVD has affects clinical management of APS patients. PMID:23456852

  7. Live three-dimensional transesophageal echocardiography in mitral valve surgery

    Institute of Scientific and Technical Information of China (English)

    MA Ning; LI Zhi-an; MENG Xu; YANG Ya

    2008-01-01

    Background Live three-dimensional transesophageal echocardiography (live-3D-TEE) is a new technique, but its clinical value is unclear at present. This study aimed to investigate the feasibility, imaging quality and accuracy of live-3D-TEE for assessing mitral valve morphology to determine if live-3D-TEE has important value in mitral valve surgery.Methods Twenty-four patients with mitral valve disease (mean age (47.1 rdiography (2D-TEE) before and after mitral valve surgery. Sensitivity, specificity, and total consistency rates of live-3D-TEE for diagnosing ruptured chordae were calculated and compared to surgeon's findings. We also compared the diagnostic accuracy of mitral valve disease between live-3D-TEE and 2D-TEE.Results Live-3D-TEE allowed visualization of the anatomic structure of the heart online and clearly identified the valvular apparatus and their defects. Sensitivity and specificity for the detection of ruptured chordae by live-3D-TEE were 87.5% and 100% respectively, and the total consistency rate was 95.8%. Additional defects not diagnosted by 2D-TEE were found in three cases (12.5%) preoperatively by live-3D-TEE. Live-3D-TEE could evaluate the function of prosthetic or native valves immediately after operation. One case was re-repaired (4.2%) using guidance by live-3D-TEE. Conclusion Live-3D-TEE enabled evaluation of mitral valve function and provided adequate valuable information before and after mitral valve surgery. We conclude that live-3D-TEE can play an important role in mitral valve surgery.

  8. In vitro flow dynamics of four prosthetic aortic valves: a comparative analysis.

    Science.gov (United States)

    Hanle, D D; Harrison, E C; Yoganathan, A P; Allen, D T; Corcoran, W H

    1989-01-01

    The velocity fields downstream of four prosthetic heart valves were mapped in vitro over the entire cross-section of a model aortic root using laser Doppler anemometry. THe Björk-Shiley 60 degrees convexo-concave tilting disc valve, the Smeloff-Cutter caged ball valve, the St. Jude Medical bileaflet valve, and the Ionescu-Shiley standard bioprosthesis were examined under both steady and pulsatile flows. Velocity profiles under steady flow conditions were a good approximation for pulsatile profiles only during midsystole. The pulsatile flow characteristics of the four valves showed variation in large scale flow structures. Comparison of the valves according to pressure drop, shear stress and maximum velocities are also provided. PMID:2808443

  9. Perioperative management of patient with Bombay blood group undergoing mitral valve replacement

    Directory of Open Access Journals (Sweden)

    Shio Priye

    2015-01-01

    Full Text Available Bombay red blood cell phenotype is an extremely rare blood type for which patients can receive only autologous or Bombay phenotype red blood cells. We report a case of stenotic mitral valve with Bombay phenotype who underwent minimal invasive right lateral thoracotomy for the replacement of the mitral valve. A male patient from Bangladesh presented to the hospital with New York Heart Association III symptoms. His medical evaluation revealed severe mitral valve stenosis and mild aortic valve regurgitation. The patient received erythropoietin, intravenous iron succinate and folic acid tablets. Autologous blood transfusion was carried out. The mitral valve was replaced with a prosthetic valve successfully. After weaning off from cardiopulmonary bypass, heparinisation was corrected with protamine. Post-operatively, the patient received autologous red blood cells. The patient recovered after 1-day of inotropic support with adrenaline and milrinone, and diuretics and was discharged on the 5 th post-operative day.

  10. Perioperative management of patient with Bombay blood group undergoing mitral valve replacement.

    Science.gov (United States)

    Priye, Shio; Sathyanarayan, J; Shivaprakash, S; Reddy, Durgaprasad

    2015-12-01

    Bombay red blood cell phenotype is an extremely rare blood type for which patients can receive only autologous or Bombay phenotype red blood cells. We report a case of stenotic mitral valve with Bombay phenotype who underwent minimal invasive right lateral thoracotomy for the replacement of the mitral valve. A male patient from Bangladesh presented to the hospital with New York Heart Association III symptoms. His medical evaluation revealed severe mitral valve stenosis and mild aortic valve regurgitation. The patient received erythropoietin, intravenous iron succinate and folic acid tablets. Autologous blood transfusion was carried out. The mitral valve was replaced with a prosthetic valve successfully. After weaning off from cardiopulmonary bypass, heparinisation was corrected with protamine. Post-operatively, the patient received autologous red blood cells. The patient recovered after 1-day of inotropic support with adrenaline and milrinone, and diuretics and was discharged on the 5(th) post-operative day.

  11. Anticoagulation dilemma in a high-risk patient with On-X valves

    Directory of Open Access Journals (Sweden)

    Ami M Karkar

    2015-01-01

    Full Text Available Thromboembolism continues to be a major concern in patients with mechanical heart valves, especially in those with unsatisfactory anticoagulation levels. The new On-X valve (On-X Life Technologies, Austin, TX, USA has been reported as having unique structural characteristics that offer lower thrombogenicity to the valve. We report a case where the patient received no or minimal systemic anticoagulation after placement of On-X mitral and aortic valves due to development of severe mucosal arterio-venous malformations yet did not show any evidence of thromboembolism. This case report reinforces the findings of recent studies that lower anticoagulation levels may be acceptable in patients with On-X valves and suggests this valve may be particularly useful in those in whom therapeutic levels of anticoagulation cannot be achieved due to increased risk of bleeding.

  12. Atrioventricular valve replacement in functional single-ventricle patients

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhong; CEN Jian-zheng; XU Gang; WEN Shu-sheng; CHEN Ji-mei

    2016-01-01

    Background This article summarized the experience of atrioventricular valve replacement operation for functional single ventricle patients whose atrioventricular valve was insufficiency.The follow-up time of operation was arranged from early-to medium-term.Methods From July 2009 to July 2015,there were 40 patients of functional single ventricle receiving the operation of atrioventricular valve replacement,including 23 male and 17 female patients.The age at A-Ⅴ valve replacement was ranged from 6 days to 32 years (the medium age of 9 years),and the body weight ranged from 2.7 to 57 kg (the medium body weight of 21.5 kg).Moreover,the atrioventricular valve replacement was performed on all patients under extracorporeal circulation.Results Atrioventricular valve replacement was performed on 40 patients with function single ventricle in hospital,of which eight (20.0%) died in hospital including two neonate and infant (age range:6 days-2 years old) accounting for 25% (2/8),Among them,seven patients died of low cardiac output syndrome two patients with repeated hypoxemia concurrent infection after operation,and one with bilateral diaphragmatic paralysis and malignant arrhythmia.For the patients suffering the severe perivalvular leakage,there was a reoperation,and the cardiac function before the first operation was class Ⅳ.One patient received heart transplantation finally for severe heart failure after AV valve replacement.For the rest of patients,their cardiac function recovered to class Ⅰ-Ⅱ after operation.Conclusions For function single ventricle patients with atrioventricular valve regurgitation,the mortality rate of atrioventricular valve replacement can be accepted if the operation was indicated.For patients with severe atrioventricular value regurgitation,the result of the operation in the early and medium term was satisfying.Thus,the atrioventricular valve replacement served as a useful treatment for patients diagnosed of A-Ⅴ valve regurgitation and

  13. Histopathological study of congenital aortic valve malformations in 32 children

    Institute of Scientific and Technical Information of China (English)

    HUANG Ping; WANG Hongwei; LI Yanping; CHENG Peixuan; LIU Qingjun; ZHANG Zhenlu; LIU Jianying

    2007-01-01

    The histopathological characteristics of congenital aortic valve malformations in children were investigated.All the native surgically excised aortic valves from 32 pediatric patients suffering from symptomatic aortic valve dysfunction due to congenital aortic valve malformations between January 2003 and December 2005 were studied macroscopically and microscopically.The patients' medical records were reviewed and the clinical information was extracted.The diagnosis was made by the clinical presentation,preoperative echocardiography,intraoperative examination,and postoperative histopathological study,excluding rheumatic ot degenerative aortic valve diseases,infective endocarditis and primary connective tissue disorders,e.g.Marfan syndrome.Among 32 children with congenital aortic valve malformations,the age was ranged from six to 18 years,with a mean of 14.9 years,and there were 27 boys and five girls (male:female = 5.4:1).There were five cases of aortic stenosis (AS,15.62%),25 cases of aortic insufficiency (AI,78.13 %)and two cases of AS-AI (6.25%),without other valve diseases.Twenty cases still had other congenital heart diseases:ventricular septal defect (19 cases),patent ductus arteriosus (two cases),double-chambered right ventricle (one case),aneurysm of the right anterior aortic sinus of valsalva (three cases).Histopathological examination indicated that the cusps became thickening with unequal size,irregular shape (coiling and prolapse edge),enhanced hardness,and partly calcification.Microscopic investigation revealed the unsharp structure of valve tissue,fibrosis,myxomatous,reduced collagen fiber,rupture of elastic fibers,different degrees of infiltration of inflammatory cells,secondary calcareous and lipid deposit,and secondary fibrosis.Congenital aortic valve malformations in children involve males more than females,mostly associated with other congenital heart diseases.Aortic insufficiency is more common in children with congenital aortic valve

  14. [Technologies for cardiac valve prostheses].

    Science.gov (United States)

    Nakano, Kiyoharu

    2009-07-01

    To show the technological development of cardiac valve prostheses, a historical review of both mechanical and biological valve prostheses and a current overview of modern cardiac valve devices are provided. Scince the 1st implantation of Starr-Edwards ball valve in 1960, both mechanical and biological valve prostheses have advanced. The valve design, the material of the leaflet and the hausing of mechanical prostheses have improved. Currently, the majority of the mechanical prostheses are bileaflet tilting disc valves made of pyrolytic carbon, which is antithromboembolic. However, anticoagulation therapy with warfarin is still required. As for the bioprostheses, although the fixation and anti-mineralization methods of the tissues improved, the durability of these valves is still limited. For the material of the current biological valves, the porcine aortic valve or bovine pericardium are used. The tissues are fixed by non-pressure or low-pressure method in glutaraldehyde solution. A stented and non-stented valves are available. Epoch-making events in this field are the implantation of new bioprosthetic valves using tissue engineering methods and the development of the transcatheter valve replacement therapies.

  15. Emission-free valve

    Energy Technology Data Exchange (ETDEWEB)

    Koppe, W.; Prummer, R.

    1980-07-01

    a description is given of an emission-free valve, particularly a magnetically operated valve, for use in controlling the flow of fluids, especially poisonous, radioactive, aggressive and otherwise dangerous gases and fluids, comprising a housing including a housing member which has substantially spherical configuration and an internal surface surrounding a compartment for the respective fluid, said housing further including an annular valve seat member; a valve member movably mounted in said compartment and cooperating with said valve seat member to control the flow of the fluid through said compartment; and a plating layer of a corrosion-resistant material covering said internal surface of said housing member and also having a substantially spherical configuration corresponding to that of said housing member, said housing member and said plating layer obtaining their respective configurations during an explosion which not only simultaneously deforms initially cylindrical tubular and coaxially arranged housing member and plating layer preforms, but also welds said plating layer preform to said housing member preform so that said platinglayer is explosion-welded to said housing member.

  16. Transcatheter Aortic Valve Replacement for Degenerative Bioprosthetic Surgical Valves

    DEFF Research Database (Denmark)

    Dvir, Danny; Webb, John; Brecker, Stephen;

    2012-01-01

    Transcatheter aortic valve-in-valve implantation is an emerging therapeutic alternative for patients with a failed surgical bioprosthesis and may obviate the need for reoperation. We evaluated the clinical results of this technique using a large, worldwide registry.......Transcatheter aortic valve-in-valve implantation is an emerging therapeutic alternative for patients with a failed surgical bioprosthesis and may obviate the need for reoperation. We evaluated the clinical results of this technique using a large, worldwide registry....

  17. Simulation for transthoracic echocardiography of aortic valve

    Science.gov (United States)

    Nanda, Navin C.; Kapur, K. K.; Kapoor, Poonam Malhotra

    2016-01-01

    Simulation allows interactive transthoracic echocardiography (TTE) learning using a virtual three-dimensional model of the heart and may aid in the acquisition of the cognitive and technical skills needed to perform TTE. The ability to link probe manipulation, cardiac anatomy, and echocardiographic images using a simulator has been shown to be an effective model for training anesthesiology residents in transesophageal echocardiography. A proposed alternative to real-time reality patient-based learning is simulation-based training that allows anesthesiologists to learn complex concepts and procedures, especially for specific structures such as aortic valve. PMID:27397455

  18. Aortic Annular Enlargement during Aortic Valve Replacement

    Directory of Open Access Journals (Sweden)

    Selman Dumani

    2016-09-01

    Full Text Available In the surgery of aortic valve replacement is always attempted, as much as possible, to implant the larger prosthesis with the mains goals to enhance the potential benefits, to minimise transvalvular gradient, decrease left ventricular size and avoid the phenomenon of patient-prosthesis mismatch. Implantation of an ideal prosthesis often it is not possible, due to a small aortic annulus. A variety of aortic annulus enlargement techniques is reported to avoid patient-prosthesis mismatch. We present the case that has submitted four three times open heart surgery. We used Manouguian technique to enlarge aortic anulus with excellent results during the fourth time of surgery.

  19. The Evolving Role of Percutaneous Mitral Valve Repair

    Science.gov (United States)

    Stewart, Merrill H.; Jenkins, J. Stephen

    2016-01-01

    Background: Mitral regurgitation (MR) is the second leading cause of valvular heart disease in the United States behind aortic stenosis. The percutaneous repair of the mitral valve (MitraClip, Abbott, Inc.) has been approved in the United States since 2013 as an alternative to traditional mitral valve surgery. However, many questions are left unanswered about when to perform this procedure and whom to perform it on. Methods: We reviewed major published literature on the MitraClip from 2003-2016 to help guide clinical decision-making. A PubMed search was conducted using the phrase “mitraclip” or “percutaneous mitral valve repair” to identify relevant articles pertaining to the clip as well as surgical valve repair. Results: The clinical trials EVEREST I and EVEREST II (Endovascular Valve Edge-to-Edge Repair Study) demonstrated the safety and efficacy of the MitraClip but did not prove its superiority to surgical repair in the population studied. Numerous subsequent registries have suggested that the success of the MitraClip varies with the patient population studied. The currently enrolling Cardiovascular Outcomes for Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients with Functional MR (COAPT) trial hopes to answer some of these questions. Conclusion: The MitraClip is a new and exciting technology for percutaneously treating disease processes traditionally managed with surgery. The future of the clip and its patient population is dependent on further studies. PMID:27660576

  20. Comparative hemodynamics in an aorta with bicuspid and trileaflet valves

    Science.gov (United States)

    Gilmanov, Anvar; Sotiropoulos, Fotis

    2016-04-01

    Bicuspid aortic valve (BAV) is a congenital heart defect that has been associated with serious aortopathies, such as aortic stenosis, aortic regurgitation, infective endocarditis, aortic dissection, calcific aortic valve and dilatation of ascending aorta. There are two main hypotheses to explain the increase prevalence of aortopathies in patients with BAV: the genetic and the hemodynamic. In this study, we seek to investigate the possible role of hemodynamic factors as causes of BAV-associated aortopathy. We employ the curvilinear immersed boundary method coupled with an efficient thin-shell finite-element formulation for tissues to carry out fluid-structure interaction simulations of a healthy trileaflet aortic valve (TAV) and a BAV placed in the same anatomic aorta. The computed results reveal major differences between the TAV and BAV flow patterns. These include: the dynamics of the aortic valve vortex ring formation and break up; the large-scale flow patterns in the ascending aorta; the shear stress magnitude, directions, and dynamics on the heart valve surfaces. The computed results are in qualitative agreement with in vivo magnetic resonance imaging data and suggest that the linkages between BAV aortopathy and hemodynamics deserve further investigation.