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Sample records for bi-leaflet heart valve

  1. Platelet activation through a Bi-leaflet mechanical heart valve

    Science.gov (United States)

    Hedayat, Mohammadali; Borazjani, Iman

    2016-11-01

    Platelet activation is one of the major drawbacks of the Mechanical Heart Valves (MHVs) which can increase the risk of thrombus formation in patients. The platelet activation in MHVs can be due to the abnormal shear stress during the systole, the backward leakage flow during the diastole, and the flow through the hinge region. We investigate the contribution of each of the above mechanism to the activation of platelets in MHVs by performing simulations of the flow through the MHV and in the hinge region. The large scale heart valve simulations are performed in a straight aorta using a sharp interface curvilinear immersed boundary method along with a strong-coupling algorithm under physiological flow conditions. In addition, in order to perform the simulation of hinge region the flow field boundary conditions are obtained from the largescale simulations during a whole cardiac cycle. In order to investigate the role of hinge flow on platelet activation in MHVs, a 23mm St. Jude Medical Regent valve hinge with three different gap sizes is tested along with different platelet activation models to ensure the consistency of our results with different activation models. We compare the platelet activation of the hinge region against the bulk of the flow during one cardiac cycle. This work is supported by the American Heart Association Grant 13SDG17220022, and the computational resources were partly provided by Center for Computational Research (CCR) at University at Buffalo.

  2. 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.

  3. 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

  4. Mid- to long-term outcome comparison of the Medtronic Hancock II and bi-leaflet mechanical aortic valve replacement in patients younger than 60 years of age: a propensity-matched analysis.

    Science.gov (United States)

    Wang, Yin; Chen, Si; Shi, Jiawei; Li, Geng; Dong, Nianguo

    2016-03-01

    This study aims to compare mid-long-term clinical outcomes between patients younger than 60 years of age undergoing bioprosthetic and mechanical aortic valve replacement. From January 2002 to December 2009, patients younger than 60 years of age who received Medtronic Hancock II porcine bioprostheses were selected and compared with those who received mechanical bi-leaflet valves in the aortic position. A stepwise logistic regression propensity score identified a subset of 112 evenly matched patient-pairs. Mid-long-term outcomes of survival, valve-related reoperations, thromboembolic events and bleeding events were assessed. The follow-up was only 95.1% complete. Fourteen measurable variables were statistically similar for the matched cohort. Postoperative in-hospital mortality was 3.6% (bioprosthetic valves) and 2.7% (mechanical valves) (P = 0.700). Survival at 5 and 10 years was 96.3 and 88.7% for patients receiving bioprosthetic valve replacement versus 96.3 and 87.9% for patients receiving mechanical valve replacement (P = 0.860), respectively. At 5 and 10 years after operations, freedom from valve-related reoperation was 97.2 and 94.8% for patients receiving mechanical valve replacement, and 96.3 and 90.2% for patients receiving bioprosthetic valve replacement (P = 0.296), respectively. There was no difference between freedom from thromboembolic events (P = 0.528) and bleeding events (P = 0.128) between the matched groups during the postoperative 10 years. In patients younger than 60 years of age undergoing aortic valve replacement, mid-long-term survival rate was similar for patients receiving bioprosthetic versus mechanical valve replacement. Bioprosthetic valves were associated with a trend for a lower risk of anticoagulation treatment and did not have significantly greater likelihood of a reoperation. These findings suggest that a bioprosthetic valve may be a reasonable choice for AVR in patients younger than 60 years of age. © The Author 2015. Published by

  5. 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.

  6. 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.

  7. Heart valve surgery

    Science.gov (United States)

    ... Tricuspid valve stenosis Risks The risks of having cardiac surgery include: Death Heart attack Heart failure Bleeding requiring ... and the A.D.A.M. Editorial team. Heart Surgery Read more Heart Valve Diseases Read more Latest ...

  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. Heart valve surgery - discharge

    Science.gov (United States)

    ... ACC guideline for the management of patients with valvular heart disease: executive summary: a report of the American College ... Editorial team. Related MedlinePlus Health Topics Heart Surgery Heart Valve Diseases Browse the Encyclopedia A.D.A.M., Inc. ...

  10. 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.

  11. What Causes Heart Valve Disease?

    Science.gov (United States)

    ... a heart attack or injury to the heart. Rheumatic Fever Untreated strep throat or other infections with strep bacteria that progress to rheumatic fever can cause heart valve disease. When the body ...

  12. 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...

  13. 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.

  14. Problem: Heart Valve Stenosis

    Science.gov (United States)

    ... Cholesterol Tools & Resources Congenital Defects Children & Adults About Congenital Heart Defects The Impact of Congenital Heart Defects Understand Your Risk for Congenital Heart Defects Symptoms & ...

  15. Problem: Heart Valve Regurgitation

    Science.gov (United States)

    ... Cholesterol Tools & Resources Congenital Defects Children & Adults About Congenital Heart Defects The Impact of Congenital Heart Defects Understand Your Risk for Congenital Heart Defects Symptoms & ...

  16. 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.

  17. Fluid mechanics of artificial heart valves.

    Science.gov (United States)

    Dasi, Lakshmi P; Simon, Helene A; Sucosky, Philippe; Yoganathan, Ajit P

    2009-02-01

    1. Artificial heart valves have been in use for over five decades to replace diseased heart valves. Since the first heart valve replacement performed with a caged-ball valve, more than 50 valve designs have been developed, differing principally in valve geometry, number of leaflets and material. To date, all artificial heart valves are plagued with complications associated with haemolysis, coagulation for mechanical heart valves and leaflet tearing for tissue-based valve prosthesis. For mechanical heart valves, these complications are believed to be associated with non-physiological blood flow patterns. 2. In the present review, we provide a bird's-eye view of fluid mechanics for the major artificial heart valve types and highlight how the engineering approach has shaped this rapidly diversifying area of research. 3. Mechanical heart valve designs have evolved significantly, with the most recent designs providing relatively superior haemodynamics with very low aerodynamic resistance. However, high shearing of blood cells and platelets still pose significant design challenges and patients must undergo life-long anticoagulation therapy. Bioprosthetic or tissue valves do not require anticoagulants due to their distinct similarity to the native valve geometry and haemodynamics, but many of these valves fail structurally within the first 10-15 years of implantation. 4. These shortcomings have directed present and future research in three main directions in attempts to design superior artificial valves: (i) engineering living tissue heart valves; (ii) development of advanced computational tools; and (iii) blood experiments to establish the link between flow and blood damage.

  18. Fracturing mechanics before valve-in-valve therapy of small aortic bioprosthetic heart valves

    DEFF Research Database (Denmark)

    Johansen, Peter; Engholt, Henrik; Tang, Mariann

    2017-01-01

    AIMS: Patients with degraded bioprosthetic heart valves (BHV) who are not candidates for valve replacement may benefit from transcatheter valve-in-valve (VIV) therapy. However, at smaller sized surgical BHV the resultant orifice may become too narrow. To overcome this, the valve frame can be frac...

  19. Computed Tomography of Prosthetic Heart Valves

    NARCIS (Netherlands)

    Habets, J.

    2012-01-01

    Prosthetic heart valve (PHV) dysfunction is an infrequent but potentially life-threatening disease with a heterogeneous clinical presentation. Patients with PHV dysfunction clinically can present with symptoms of congestive heart failure (dyspnea, fatigue, edema), fever, angina pectoris, dizziness d

  20. 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.

  1. 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....

  2. Computed Flow Through An Artificial Heart Valve

    Science.gov (United States)

    Rogers, Stewart E.; Kwak, Dochan; Kiris, Cetin; Chang, I-Dee

    1994-01-01

    Report discusses computations of blood flow through prosthetic tilting disk valve. Computational procedure developed in simulation used to design better artificial hearts and valves by reducing or eliminating following adverse flow characteristics: large pressure losses, which prevent hearts from working efficiently; separated and secondary flows, which causes clotting; and high turbulent shear stresses, which damages red blood cells. Report reiterates and expands upon part of NASA technical memorandum "Computed Flow Through an Artificial Heart and Valve" (ARC-12983). Also based partly on research described in "Numerical Simulation of Flow Through an Artificial Heart" (ARC-12478).

  3. Heart Valve Biomechanics and Underlying Mechanobiology

    Science.gov (United States)

    Ayoub, Salma; Ferrari, Giovanni; Gorman, Robert C.; Gorman, Joseph H.; Schoen, Frederick J.; Sacks, Michael S.

    2017-01-01

    Heart valves control unidirectional blood flow within the heart during the cardiac cycle. They have a remarkable ability to withstand the demanding mechanical environment of the heart, achieving lifetime durability by processes involving the ongoing remodeling of the extracellular matrix. The focus of this review is on heart valve functional physiology, with insights into the link between disease-induced alterations in valve geometry, tissue stress, and the subsequent cell mechanobiological responses and tissue remodeling. We begin with an overview of the fundamentals of heart valve physiology and the characteristics and functions of valve interstitial cells (VICs). We then provide an overview of current experimental and computational approaches that connect VIC mechanobiological response to organ- and tissue-level deformations and improve our understanding of the underlying functional physiology of heart valves. We conclude with a summary of future trends and offer an outlook for the future of heart valve mechanobiology, specifically, multiscale modeling approaches, and the potential directions and possible challenges of research development. PMID:27783858

  4. 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.

  5. 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.

  6. 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.

  7. Recellularization of decellularized heart valves: Progress toward the tissue-engineered heart valve

    Science.gov (United States)

    VeDepo, Mitchell C; Detamore, Michael S; Hopkins, Richard A; Converse, Gabriel L

    2017-01-01

    The tissue-engineered heart valve portends a new era in the field of valve replacement. Decellularized heart valves are of great interest as a scaffold for the tissue-engineered heart valve due to their naturally bioactive composition, clinical relevance as a stand-alone implant, and partial recellularization in vivo. However, a significant challenge remains in realizing the tissue-engineered heart valve: assuring consistent recellularization of the entire valve leaflets by phenotypically appropriate cells. Many creative strategies have pursued complete biological valve recellularization; however, identifying the optimal recellularization method, including in situ or in vitro recellularization and chemical and/or mechanical conditioning, has proven difficult. Furthermore, while many studies have focused on individual parameters for increasing valve interstitial recellularization, a general understanding of the interacting dynamics is likely necessary to achieve success. Therefore, the purpose of this review is to explore and compare the various processing strategies used for the decellularization and subsequent recellularization of tissue-engineered heart valves. PMID:28890780

  8. Living artificial heart valve alternatives: a review

    Directory of Open Access Journals (Sweden)

    Flanagan T. C.

    2003-11-01

    Full Text Available Conventional replacement therapies for heart valve disease are associated with significant drawbacks. The field of tissue engineering has emerged as an exciting alternative in the search for improved heart valve replacement structures. One of the principles behind this concept is the transplantation of living elements, embedded in a suitable scaffold material, to the diseased site where the structure becomes integrated with patients' tissue to restore natural function. Significant progress has been made in the last ten years in the development of a living artificial heart valve alternative (LAHVA, with the identification of potential replacement sources for valve cells, scaffolds to maintain the cells in a three-dimensional environment, and signals to promote tissue development. This review addresses the need for a tissue-engineered alternative to current prostheses and provides a detailed account of normal heart valve structure - the blueprint for LAHVA fabrication. The research efforts to create a viable LAHVA, including recent developments, are discussed. Particular attention is focused on the choice of cell source for LAHVA construction, the use of biodegradable natural and synthetic polymeric scaffolds as extracellular matrix derivatives, and exogenous stimulation of tissue growth. The critical challenges involved in LAHVA development and possible future areas of investigation are also discussed.

  9. 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.

  10. Multimodality Imaging of Heart Valve Disease

    Directory of Open Access Journals (Sweden)

    Ronak Rajani

    2014-09-01

    Full Text Available 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.

  11. On-pump fibrillating heart mitral valve replacement with the SAPIEN™ XT transcatheter heart valve.

    Science.gov (United States)

    Ferrari, Enrico; Niclauss, Lars; Locca, Didier; Marcucci, Carlo

    2014-04-01

    In some high-risk patients, standard mitral valve replacement can represent a challenging procedure, requiring a risky extensive decalcification of the annulus. In particular, high-risk redo patients and patients with a previously implanted transcatheter aortic valve, who develop calcific mitral disease, would benefit from the development of new, minimally invasive, transcatheter or hybrid techniques for mitral valve replacement. In particular, mixing transcatheter valve therapies and well-established minimally invasive techniques for mitral replacement or repair can help in decreasing the surgical risk and the technical complexity. Thus, placing transcatheter, balloon-expandable Sapien™ XT stent-valves in calcified, degenerated mitral valves through a right thoracotomy, a left atriotomy and on an on-pump fibrillating heart, represents an attractive alternative to standard surgery in redo patients, in patients with concomitant transcatheter aortic stent-valves in place and in patients with a high-risk profile. We describe this hybrid technique in detail.

  12. 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...

  13. 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

  14. [Fluid solid interaction analysis of bioprosthetic heart valve].

    Science.gov (United States)

    Ma, Xuejie; Du, Yawei; Zhang, Linan; Hou, Zengtao; Ye, Xin

    2014-09-01

    This paper constructs numerical models of bioprosthetic heart valve and blood. The fluid solid interaction is carried out using penalty function method. The mechanical property of the bioprosthetic heart valve during cardiac cycle is simulated with ANSYS software. Results show that the Von Mises stress concentrates at the junction of attachment edge and coaptation edge. The open time of bioprosthetic heart valve is consistent with that of actural measurement. The peak velocity of blood is in the range of physiology. This model provides more realistic mechanical property of bioprosthetic heart valve during cardiac cycle compared to pure solid model, and facilitates design and optimization of bioprosthetic heart valve.

  15. 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. 

  16. Risks for Heart Valve Problems

    Science.gov (United States)

    ... individual risk and the recommendations with your doctor. Aging people should also be aware of changes that may come on very gradually . Not all declines in energy or stamina are related to “the normal problems of getting older.” When the heart fails ...

  17. Lymphangiogenesis is increased in heart valve endocarditis.

    Science.gov (United States)

    Niinimäki, Eetu; Mennander, Ari A; Paavonen, Timo; Kholová, Ivana

    2016-09-15

    Inflammation-associated lymphangiogenesis (IAL) has been identified as part of several acute and chronic inflammation. Sparse data exist on lymphatics during endocarditis. Fifty-two patients with surgically resected valves were included. Endocarditis was present in 18 aortic and 10 mitral valves. Controls consisted of 15 degenerative aortic and 9 degenerative mitral valves. There were 22 males with endocarditis and 17 males in controls. The mean age was 58 (SD 15) years with endocarditis vs. 62 (SD 13) years for controls. Lymphatics were detected by podoplanin antibody immunohistochemistry and morphometrical analysis was performed. The lymphatic density in endocarditis was 833 (SD 529) vessels/mm(2) (range 0-1707) as compared with 39 (SD 60) vessels/mm(2) (range 0-250) in controls (p=0.000). In endocarditis, the mean lymphatic size was 153 (SD 372) μm(2) ranging from 1 to 2034μm(2), whereas it was 30 (SD 29) μm(2), with maximum 90μm(2) and minimum 2μm(2) in controls (p=0.000). IAL is increased in valves with endocarditis as compared with controls. Lymphatics in heart valves may provide a novel means for treatment strategies against endocarditis. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  18. Cardiac Rehabilitation After Heart Valve Surgery

    DEFF Research Database (Denmark)

    Pollmann, Agathe Gerwina Elena; Frederiksen, Marianne; Prescott, Eva

    2017-01-01

    PURPOSE: Evidence of the effect of cardiac rehabilitation (CR) after heart valve surgery is scarce, but nevertheless CR is recommended for this group of patients. Therefore, this study assessed the effect of CR on exercise capacity, cardiovascular risk factors, and long-term mortality and morbidity...... ((Equation is included in full-text article.)O2peak) or 6-minute walk test (6MWT). A composite endpoint of all-cause mortality and hospital admission due to myocardial infarction, stroke, heart failure, endocarditis, revascularization, or reoperation was used to assess the hazard ratio between CR attenders...

  19. What Are the Signs and Symptoms of Heart Valve Disease?

    Science.gov (United States)

    ... notice a fluttering, racing, or irregular heartbeat. Some types of heart valve disease, such as aortic or mitral valve stenosis, can cause dizziness or fainting. ... FEAR ACT OIG CONTACT US National Institutes of Health ...

  20. 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).

  1. [Research status and development trends of the heart valve mechanical properties].

    Science.gov (United States)

    Li, Yusheng; Zeng, Pei; Ren, Guorong

    2014-10-01

    The study of mechanical properties on heart valves can provide an important theoretical basis for doctors to repair heart valves and prosthetic valve materials research. In this paper, we present the current status of the mechanical property study methods of heart valve, expound the methods and special requirements about uniaxial tensile test and biaxial tensile test of the heart valve, and further discuss several establishment methods of heart valve constitutive models. We also discuss the development trend of heart valve mechanics.

  2. Heart rate, heart rate variability, and arrhythmias in dogs with myxomatous mitral valve disease

    DEFF Research Database (Denmark)

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

    2012-01-01

    Autonomic modulation of heart rhythm is thought to influence the pathophysiology of myxomatous mitral valve disease (MMVD).......Autonomic modulation of heart rhythm is thought to influence the pathophysiology of myxomatous mitral valve disease (MMVD)....

  3. Leaky valves: new operation improves the heart's pumping action

    NARCIS (Netherlands)

    Van Kasteren, J.

    2003-01-01

    The action of any pump will start to decline when the valves no longer close properly. The same goes for the heart, the pump that maintains the circulation in our vascular system. Consequently, a major field of focus of open heart surgery is the repair or replacement of heart valves. Petr Havl a Ph.

  4. 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.

  5. Anticoagulation property and security of artificial heart valve material

    Institute of Scientific and Technical Information of China (English)

    WANG Xianghui; XU Jingfang; LIU Xianghuai; ZHANG Feng; LI Changrong; YU Liujiang; ZHENG Zhihong; WANG Xi; JIANG Zhenbin; CHEN Anqing

    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.

  6. 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…

  7. 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 

  8. The tricuspid valve in adult congenital heart disease.

    Science.gov (United States)

    Ginns, Jonathan; Ammash, Naser; Bernier, Pierre-Luc

    2014-01-01

    The tricuspid valve is frequently affected in adults with congenital heart disease but is also frequently overlooked. Disease of this valve can occur primarily or develop secondary to changes in the right ventricle caused by other disease states. The embryology and anatomy of the tricuspid valve are important to understanding pathogenesis of valve dysfunction in congenital heart disease. Clinical findings can be subtle. Multimodality imaging may be necessary to fully assess the cause and impact of tricuspid valve lesions. More research is needed in pathophysiology, imaging, and treatment in this area. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. 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....

  10. Tissue-engineered heart valve: future of cardiac surgery.

    Science.gov (United States)

    Rippel, Radoslaw A; Ghanbari, Hossein; Seifalian, Alexander M

    2012-07-01

    Heart valve disease is currently a growing problem, and demand for heart valve replacement is predicted to increase significantly in the future. Existing "gold standard" mechanical and biological prosthesis offers survival at a cost of significantly increased risks of complications. Mechanical valves may cause hemorrhage and thromboembolism, whereas biologic valves are prone to fibrosis, calcification, degeneration, and immunogenic complications. A literature search was performed to identify all relevant studies relating to tissue-engineered heart valve in life sciences using the PubMed and ISI Web of Knowledge databases. Tissue engineering is a new, emerging alternative, which is reviewed in this paper. To produce a fully functional heart valve using tissue engineering, an appropriate scaffold needs to be seeded using carefully selected cells and proliferated under conditions that resemble the environment of a natural human heart valve. Bioscaffold, synthetic materials, and preseeded composites are three common approaches of scaffold formation. All available evidence suggests that synthetic scaffolds are the most suitable material for valve scaffold formation. Different cell sources of stem cells were used with variable results. Mesenchymal stem cells, fibroblasts, myofibroblasts, and umbilical blood stem cells are used in vitro tissue engineering of heart valve. Alternatively scaffold may be implanted and then autoseeded in vivo by circulating endothelial progenitor cells or primitive circulating cells from patient's blood. For that purpose, synthetic heart valves were developed. Tissue engineering is currently the only technology in the field with the potential for the creation of tissues analogous to a native human heart valve, with longer sustainability, and fever side effects. Although there is still a long way to go, tissue-engineered heart valves have the capability to revolutionize cardiac surgery of the future.

  11. Dynamic characterization of a new accelerated heart valve tester.

    Science.gov (United States)

    Menzler, F; Haubold, A D; Hwang, N H

    1997-01-01

    This paper presents a new accelerated prosthetic heart valve tester prototype that incorporates a camshaft and poppet valves. A three element Windkessel system is used to mimic the afterload of the human systemic circulation. The device is capable of testing eight valves simultaneously at a rate up to 1,250 cycles/min, while the flow rate, the pressure, and the valve loading can be monitored and adjusted individually. The tester was characterized and calibrated using a set of eight Carpentier-Edwards bioprostheses at a flow rate varying between 3 and 5 L/min. The experiment was carried out with the pressure difference across the closed heart valve maintained between 140 and 190 mmHg. Smooth and complete opening and closing of the valve leaflets was achieved at all cycling rates. This confirms that the velocity profiles approaching the test valves were uniform, an important factor that allows the test valves to open and close synchronously each time.

  12. 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.

  13. Computed Flow Through An Artificial Heart And Valve

    Science.gov (United States)

    Rogers, Stuart E.; Kwak, Dochan; Kiris, Cetin; Chang, I-Dee

    1994-01-01

    NASA technical memorandum discusses computations of flow of blood through artificial heart and through tilting-disk artificial heart valve. Represents further progress in research described in "Numerical Simulation of Flow Through an Artificial Heart" (ARC-12478). One purpose of research to exploit advanced techniques of computational fluid dynamics and capabilities of supercomputers to gain understanding of complicated internal flows of viscous, essentially incompressible fluids like blood. Another to use understanding to design better artificial hearts and valves.

  14. 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.

  15. Current Status of Tissue Engineering Heart Valve.

    Science.gov (United States)

    Shinoka, Toshiharu; Miyachi, Hideki

    2016-11-01

    The development of surgically implantable heart valve prostheses has contributed to improved outcomes in patients with cardiovascular disease. However, there are drawbacks, such as risk of infection and lack of growth potential. Tissue-engineered heart valve (TEHV) holds great promise to address these drawbacks as the ideal TEHV is easily implanted, biocompatible, non-thrombogenic, durable, degradable, and ultimately remodels into native-like tissue. In general, three main components used in creating a tissue-engineered construct are (1) a scaffold material, (2) a cell type for seeding the scaffold, and (3) a subsequent remodeling process driven by cell accumulation and proliferation, and/or biochemical and mechanical signaling. Despite rapid progress in the field over the past decade, TEHVs have not been translated into clinical applications successfully. To successfully utilize TEHVs clinically, further elucidation of the mechanisms for TEHV remodeling and further translational research outcome evaluations will be required. Tissue engineering is a major breakthrough in cardiovascular medicine that holds amazing promise for the future of reconstructive surgical procedures. In this article, we review the history of regenerative medicine, advances in the field, and state-of-the-art in valvular tissue engineering. © The Author(s) 2016.

  16. Carcinoid heart disease : outcomes after surgical valve replacement

    NARCIS (Netherlands)

    Mokhles, Palwasha; van Herwerden, Lex A.; de Jong, Peter L.; de Herder, Wouter W.; Siregar, Sabrina; Constantinescu, Alina A.; van Domburg, Ron T.; Roos-Hesselink, Jolien W.

    2012-01-01

    To describe the early and late outcomes of carcinoid patients undergoing surgical heart valve replacement. In a retrospective study, records of patients with symptomatic carcinoid heart disease referred for valve surgery between 1993 and 2010 at two academic centres were reviewed. The perioperative

  17. Antithrombotic Therapy in Patients with Prosthetic Heart Valves

    Directory of Open Access Journals (Sweden)

    Mohamed HA

    2009-01-01

    Full Text Available Patients with mechanical valve prostheses require a lifelong anticoagulant treatment. The combined use of Warfarin and low-dose aspirin appears to reduce the risk of valve thrombosis and systemic embolism at a low risk of bleeding. The management of women with prosthetic heart valves during pregnancy poses a particular challenge, as there are no available controlled clinical trials to provide guidelines for effective antithrombotic therapy. Oral anticoagulants, such as Warfarin, cause foetal embryopathy; unfractionated heparin and low-molecular-weight heparin have been reported to be ineffective in preventing thromboembolic complications.This article discusses the available data and the most recent guidelines in the antithrombotic management of patients with prosthetic valves, and antithrombotic therapy in various clinical situations such as pregnant women with prosthetic heart valves, and patients with prosthetic heart valves undergoing noncardiac surgery.

  18. Valve Disease

    Science.gov (United States)

    ... heart valves, valve insufficiency, valve regurgitation, valve stenosis, valvular heart disease Every time your heart beats, blood flows into, ... removed from the market after being linked to heart valve disease. An infection in the lining of the heart's ...

  19. 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.

  20. 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...... expensive outpatient visits. Further studies should investigate the benefits of CR to heart valve surgery patients as part of a formal cost-utility analysis....

  1. 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....

  2. High readmission rate after heart valve surgery

    DEFF Research Database (Denmark)

    Sibilitz, K L; Berg, S K; Thygesen, Lau Caspar;

    2015-01-01

    of anxiety and depression were present in 13.6% and 13.8%, respectively (Hospital Anxiety and Depression Scale score ≥ 8). Twelve months following discharge, 483 persons (56%) were readmitted. Readmission was associated with lower self-reported health (SF-36 PCS: 46.5 vs. 43.9, and MCS 52.2 vs. 50.7). Higher...... after surgery (3.2 (1.2-8.9)) predicted mortality. CONCLUSIONS: 6-12 months after heart valve surgery the readmission rate is high and the self-reported health status is low. Readmission is associated with low self-reported health. Therefore, targeted follow-up strategies post-surgery are needed....

  3. 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.

  4. 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.

  5. TCT-670 Optimal Transcatheter Heart Valve Sizing in Aortic Valve in Valve Implantation: Insights from the Valve in Valve International Data (VIVID) Registry

    DEFF Research Database (Denmark)

    Alnasser, Sami; Cheema, Asim N; Horlick, Eric

    2016-01-01

    Background: Optimal transcatheter heart valve (THV) sizing is crucial to optimize procedural outcomes. Larger THV oversizing is shown to decrease paravalvular leakage post transcatheter aortic valve replacement but its role in Valve in Valve implantation (ViV) is not well established. Methods...... group received a larger THV (25.5± 1.4 mm vs. 23.3 ± 1.0 mm, pimplantation, the oversized group achieved a larger EOA (1.54±0.4cm2 vs. 1.37± 0.5cm2, p...V implantation was associated with favorable post-implant EOA and gradient but a higher risk of aortic insufficiency and THV re-intervention. Further exploration within various THV and surgical valve types at different degree of THV oversizing is planned....

  6. Pregnancy in women with prosthetic heart valves

    NARCIS (Netherlands)

    Pieper, P. G.; Balci, A.; Van Dijk, A. P.

    2008-01-01

    Pregnancy in women with mechanical valve prostheses has a high maternal complication rate including valve thrombosis mid death. Coumarin derivatives are relatively safe for the mother with a lower incidence of valve thrombosis than unfractionated and low-molecular-weight heparin, but carry the risk

  7. Loss of Axin2 results in impaired heart valve maturation and subsequent myxomatous valve disease.

    Science.gov (United States)

    Hulin, Alexia; Moore, Vicky; James, Jeanne M; Yutzey, Katherine E

    2017-01-01

    Myxomatous valve disease (MVD) is the most common aetiology of primary mitral regurgitation. Recent studies suggest that defects in heart valve development can lead to heart valve disease in adults. Wnt/β-catenin signalling is active during heart valve development and has been reported in human MVD. The consequences of increased Wnt/β-catenin signalling due to Axin2 deficiency in postnatal valve remodelling and pathogenesis of MVD were determined. To investigate the role of Wnt/β-catenin signalling, we analysed heart valves from mice deficient in Axin2 (KO), a negative regulator of Wnt/β-catenin signalling. Axin2 KO mice display enlarged mitral and aortic valves (AoV) after birth with increased Wnt/β-catenin signalling and cell proliferation, whereas Sox9 expression and collagen deposition are decreased. At 2 months in Axin2 KO mice, the valve extracellular matrix (ECM) is stratified but distal AoV leaflets remain thickened and develop aortic insufficiency. Progressive myxomatous degeneration is apparent at 4 months with extensive ECM remodelling and focal aggrecan-rich areas, along with increased BMP signalling. Infiltration of inflammatory cells is also observed in Axin2 KO AoV prior to ECM remodelling. Overall, these features are consistent with the progression of human MVD. Finally, Axin2 expression is decreased and Wnt/β-catenin signalling is increased in myxomatous mitral valves in a murine model of Marfan syndrome, supporting the importance of Wnt/β-catenin signalling in the development of MVD. Altogether, these data indicate that Axin2 limits Wnt/β-catenin signalling after birth and allows proper heart valve maturation. Moreover, dysregulation of Wnt/β-catenin signalling resulting from loss of Axin2 leads to progressive MVD. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For Permissions, please email: journals.permissions@oup.com.

  8. 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

  9. 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.

  10. When a Heart Murmur Signals Valve Disease

    Science.gov (United States)

    ... Cholesterol Tools & Resources Congenital Defects Children & Adults About Congenital Heart Defects The Impact of Congenital Heart Defects Understand Your Risk for Congenital Heart Defects Symptoms & ...

  11. JetValve: Rapid manufacturing of biohybrid scaffolds for biomimetic heart valve replacement.

    Science.gov (United States)

    Capulli, Andrew K; Emmert, Maximillian Y; Pasqualini, Francesco S; Kehl, Debora; Caliskan, Etem; Lind, Johan U; Sheehy, Sean P; Park, Sung Jin; Ahn, Seungkuk; Weber, Benedikt; Goss, Josue A; Hoerstrup, Simon P; Parker, Kevin Kit

    2017-07-01

    Tissue engineered scaffolds have emerged as a promising solution for heart valve replacement because of their potential for regeneration. However, traditional heart valve tissue engineering has relied on resource-intensive, cell-based manufacturing, which increases cost and hinders clinical translation. To overcome these limitations, in situ tissue engineering approaches aim to develop scaffold materials and manufacturing processes that elicit endogenous tissue remodeling and repair. Yet despite recent advances in synthetic materials manufacturing, there remains a lack of cell-free, automated approaches for rapidly producing biomimetic heart valve scaffolds. Here, we designed a jet spinning process for the rapid and automated fabrication of fibrous heart valve scaffolds. The composition, multiscale architecture, and mechanical properties of the scaffolds were tailored to mimic that of the native leaflet fibrosa and assembled into three dimensional, semilunar valve structures. We demonstrated controlled modulation of these scaffold parameters and show initial biocompatibility and functionality in vitro. Valves were minimally-invasively deployed via transapical access to the pulmonary valve position in an ovine model and shown to be functional for 15 h. Copyright © 2017 Elsevier Ltd. All rights reserved.

  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

    2015-11-01

    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-annular, trileaflet prosthetic heart valves made from styrenic block copolymers (SBC): Poli-Valves. 2 types of Poli-Valves made of SBC and differing in polystyrene fraction content were tested under continuous and pulsatile flow conditions as prescribed by ISO 5840 Standard. A pulse duplicator designed ad hoc 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 behavior of the valve. Both types of Poli-Valves met the minimum requirements in terms of regurgitation and EOA as specified by the ISO 5840 Standard. Results were compared with 5 mechanical heart valves (MHVs) and 5 tissue heart valves (THVs), currently available on the market. Based on these results, PHVs based on styrenic block copolymers, as are Poli-Valves, can be considered a promising alternative for heart valve replacement in the near future.

  14. Role of CT in patients with prosthetic heart valves

    NARCIS (Netherlands)

    Suchá, D.

    2016-01-01

    Valvular heart disease accounts for a substantial part of the cardiovascular disease worldwide with an estimated prevalence of 2.5% in the Western population aged <65 years and over 13% in the population aged >75 years. Surgical prosthetic heart valve (PHV) replacement is the indicated therapy for

  15. Hydrodynamic Performance of the Medtronic CoreValve and the Edwards SAPIEN XT Transcatheter Heart Valve in Surgical Bioprostheses: An In Vitro Valve-in-Valve Model.

    Science.gov (United States)

    Sedaghat, Alexander; Sinning, Jan-Malte; Utzenrath, Marc; Ghalati, Pejman Farhadi; Schmitz, Christoph; Werner, Nikos; Nickenig, Georg; Grube, Eberhard; Ensminger, Stephan; Steinseifer, Ulrich; Kuetting, Maximilian

    2016-01-01

    Valve-in-valve transcatheter aortic valve replacement (TAVR) is becoming a valuable option with promising clinical results in failed bioprosthetic heart valves. Sizing recommendations are based on size compatibility rather than on broad clinical data, in vitro measurements, or biomechanical evidence. The hemodynamic performance of transcatheter heart valves within degenerated surgical heart valves is unknown. We evaluated the in vitro hydrodynamic performance of two commercially available transcatheter heart valves (Medtronic CoreValve [Medtronic, Minneapolis, MN] and Edwards SAPIEN XT [Edwards Lifesciences, Irvine, CA]) in two different bioprosthetic aortic valves (Edwards Perimount [Edwards Lifesciences] and St. Jude Trifecta [St. Jude Medical, St. Paul, MN]). Within the Edwards Perimount (23 mm) prosthesis, pressure gradients were higher for the SAPIEN XT compared with the CoreValve (11.2 ± 0.1 mm Hg versus 10.1 ± 0.1 mm Hg, p < 0.01), whereas effective orifice area (1.99 ± 0.01 cm(2) versus 1.80 ± 0.01 cm(2), p < 0.01) and total paravalvular leakage (9.0% ± 1.0% versus 5.4% ± 1.3%, p < 0.01) were increased when using the CoreValve. Similarly, measurements in the St. Jude Trifecta revealed higher transvalvular pressure gradients (13.0 ± 0.2 mm Hg versus 10.9 ± 0.3 mm Hg, p < 0.01) and lower effective orifice area for the SAPIEN XT compared with the CoreValve. However, total relative regurgitation was higher with SAPIEN XT as compared with the CoreValve in St. Jude Trifecta prostheses (11.2% ± 1.4% versus 8.3% ± 0.9%, p < 0.01). Both transcatheter heart valve prostheses performed well in the described valve-in-valve settings. Hydrodynamic results were in line with the International Organization for Standardization standards for all configurations. The observed differences indicate a necessity for preclinical valve-in-valve tests in addition to clinical long-term data about longevity. Copyright © 2016 The Society of Thoracic Surgeons. Published by

  16. 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.

  17. Application of simple biomechanical and biochemical tests to heart valve leaflets: implications for heart valve characterization and tissue engineering.

    Science.gov (United States)

    Huang, Hsiao-Ying S; Balhouse, Brittany N; Huang, Siyao

    2012-11-01

    A simple biomechanical test with real-time displacement and strain mapping is reported, which provides displacement vectors and principal strain directions during the mechanical characterization of heart valve tissues. The maps reported in the current study allow us to quickly identify the approximate strain imposed on a location in the samples. The biomechanical results show that the aortic valves exhibit stronger anisotropic mechanical behavior than that of the pulmonary valves before 18% strain equibiaxial stretching. In contrast, the pulmonary valves exhibit stronger anisotropic mechanical behavior than aortic valves beyond 28% strain equibiaxial stretching. Simple biochemical tests are also conducted. Collagens are extracted at different time points (24, 48, 72, and 120 h) at different locations in the samples. The results show that extraction time plays an important role in determining collagen concentration, in which a minimum of 72 h of extraction is required to obtain saturated collagen concentration. This work provides an easy approach for quantifying biomechanical and biochemical properties of semilunar heart valve tissues, and potentially facilitates the development of tissue engineered heart valves.

  18. 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

  19. 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.

  20. 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)

  1. 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.

  2. Human interstitial cellular model in therapeutics of heart valve calcification.

    Science.gov (United States)

    He, Caimei; Tang, Hai; Mei, Zijian; Li, Nichujie; Zeng, Zhi; Darko, Kwame Oteng; Yin, Yulong; Hu, Chien-An Andy; Yang, Xiaoping

    2017-05-23

    Calcific aortic valve disease is a common, severe heart condition that is currently with no proven, effective drug treatment and requires a surgical valve replacement or an entire heart explanation. Thus, developing novel, targeted therapeutic approaches becomes a major goal for cardiovascular disease research. To achieve this goal, isolated heart valve interstitial cells could be an advanced model to explore molecular mechanisms and measure drug efficacy. Based on this progress, molecular mechanisms that harbor components of  inflammation and fibrosis coupled with proteins, for example, BMP-2, TLRs, RANKL, Osteoprotegerin, have been proposed. Small molecules or antibodies targeting these proteins have shown promising efficacy for either reversing or slowing down calcification development in vitro. In this review, we summarize these potential therapeutics with some highlights of interstitial cellular models.

  3. 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......' perception of recovery after heart valve replacement is essential. The objective was to describe the experience of recovery at home after heart valve replacement....

  4. 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

  5. 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

  6. 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

  7. [Three-dimensional reconstruction of heart valves].

    Science.gov (United States)

    Flachskampf, F A; Kühl, H; Franke, A; Frielingsdorf, J; Klues, H; Krebs, W; Hanrath, P

    1995-08-01

    The reconstruction of three-dimensional data sets from two-dimensional echocardiographic images offers several fundamental advantages: 1. more complete data than present in the few standard 2D-view; 2. off-line generation of any desired plane, cut, or perspective after the data set has been acquired; 3. access to quantitative parameters like surface areas (e.g., of valve leaflets or portions of leaflets), volumes, and others, without geometric assumptions. The mitral valve has been the focus of several studies using various techniques of reconstruction of transthoracic or transesophageal images. These studies have shown the mitral annulus to be a non-planar, "saddle-shaped" structure, with an average distance of highest to lowest points of 14 mm in normals. This recognition of mitral annular non-planarity has led to a more stringent echocardiographic definition of mitral valve prolapse. Further studies have shown systolic shrinkage of mitral annular area by about 30% and systolic apico-basal translation of the annulus by approximately 1 cm in normals. In patients with dilated cardiomyopathy, the annulus is flattened, and both cyclic change in annular area and apico-basal translation are significantly reduced. 3D-studies of the left ventricular outflow tract in hypertrophic obstructive cardiomyopathy allow measurement of outflow tract and leaflet surface areas and dynamic spatial visualization of systolic anterior motion of the anterior mitral leaflet. Automated techniques to reconstruct the full grey value data set from a high number of parallel or rotational transesophageal planes allow impressive visualization of normal and diseased mitral and aortic valves or valve prostheses, with special emphasis on generating "surgical" views and perspectives, which cannot be obtained by conventional tomographic imaging.(ABSTRACT TRUNCATED AT 250 WORDS)

  8. A new approach to heart valve tissue engineering

    DEFF Research Database (Denmark)

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

    2011-01-01

    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......, variable throttle and reservoir, connected by silicone tubings. The reservoir sat on an elevated platform, allowing adjustment of ventricular preload between 0 and 11 mmHg. To allow for sterile gaseous exchange between the circuit interior and exterior, a 0.2 µm filter was placed at the reservoir. Pressure...

  9. 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-

  10. 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

  11. Diagnostic evaluation of left-sided prosthetic heart valve dysfunction

    NARCIS (Netherlands)

    Habets, Jesse; Budde, Ricardo P.; Symersky, Petr; van den Brink, Renee B.; de Mol, Bas A.; Mali, Willem P.; van Herwerden, Lex A.; Chamuleau, Steven A.

    2011-01-01

    Prosthetic heart valve (PHV) dysfunction is a rare, but potentially life-threatening, complication. In clinical practice, PHV dysfunction poses a diagnostic dilemma. Echocardiography and fluoroscopy are the imaging techniques of choice and are routinely used in daily practice. However, these techniq

  12. Diagnostic evaluation of left-sided prosthetic heart valve dysfunction

    NARCIS (Netherlands)

    Habets, Jesse; Budde, Ricardo P.; Symersky, Petr; van den Brink, Renee B.; de Mol, Bas A.; Mali, Willem P.; van Herwerden, Lex A.; Chamuleau, Steven A.

    2011-01-01

    Prosthetic heart valve (PHV) dysfunction is a rare, but potentially life-threatening, complication. In clinical practice, PHV dysfunction poses a diagnostic dilemma. Echocardiography and fluoroscopy are the imaging techniques of choice and are routinely used in daily practice. However, these techniq

  13. 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-

  14. 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.

  15. Heart Valve Surgery Recovery and Follow Up

    Science.gov (United States)

    ... you have any guidelines to follow concerning your heart rate or level of exertion. To improve overall cardiovascular health, follow a regular exercise program that includes moderate physical activity for 150 ...

  16. 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.

  17. In vivo behavior of epoxy-crosslinked porcine heart valve cusps and walls

    NARCIS (Netherlands)

    van Wachem, PB; Brouwer, LA; Zeeman, R; Dijkstra, PJ; Feijen, J; Hendriks, M; Cahalan, PT; van Luyn, MJA

    2000-01-01

    Calcification limits the long-term durability of xenograft glutaraldehyde-crosslinked heart valves. In this study, epoxy-crosslinked porcine aortic valve tissue was evaluated after subcutaneous implantation in weanling rats, Non-crosslinked valves and valves crosslinked with glutaraldehyde or carbod

  18. Application of hydrogels in heart valve tissue engineering.

    Science.gov (United States)

    Zhang, Xing; Xu, Bin; Puperi, Daniel S; Wu, Yan; West, Jennifer L; Grande-Allen, K Jane

    2015-01-01

    With an increasing number of patients requiring valve replacements, there is heightened interest in advancing heart valve tissue engineering (HVTE) to provide solutions to the many limitations of current surgical treatments. A variety of materials have been developed as scaffolds for HVTE including natural polymers, synthetic polymers, and decellularized valvular matrices. Among them, biocompatible hydrogels are generating growing interest. Natural hydrogels, such as collagen and fibrin, generally show good bioactivity but poor mechanical durability. Synthetic hydrogels, on the other hand, have tunable mechanical properties; however, appropriate cell-matrix interactions are difficult to obtain. Moreover, hydrogels can be used as cell carriers when the cellular component is seeded into the polymer meshes or decellularized valve scaffolds. In this review, we discuss current research strategies for HVTE with an emphasis on hydrogel applications. The physicochemical properties and fabrication methods of these hydrogels, as well as their mechanical properties and bioactivities are described. Performance of some hydrogels including in vitro evaluation using bioreactors and in vivo tests in different animal models are also discussed. For future HVTE, it will be compelling to examine how hydrogels can be constructed from composite materials to replicate mechanical properties and mimic biological functions of the native heart valve.

  19. 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.

  20. Recommendations for the management of patients after heart valve surgery.

    Science.gov (United States)

    Butchart, Eric G; Gohlke-Bärwolf, Christa; Antunes, Manuel J; Tornos, Pilar; De Caterina, Raffaele; Cormier, Bertrand; Prendergast, Bernard; Iung, Bernard; Bjornstad, Hans; Leport, Catherine; Hall, Roger J C; Vahanian, Alec

    2005-11-01

    Approximately 50,000 valve replacement operations take place in Europe annually and almost as many valve repair procedures. Previous European guidelines on management of patients after valve surgery were last published in 1995 and were limited to recommendations about antithrombotic prophylaxis. American guidelines covering the broader topic of the investigation and treatment of patients with valve disease were published in 1998 but devoted relatively little space to post-surgical management. This document represents the consensus view of a committee drawn from three European Society of Cardiology (ESC) Working Groups (WG): the WG on Valvular Heart Disease, the WG on Thrombosis, and the WG on Rehabilitation and Exercise Physiology. In almost all areas of patient management after valve surgery, randomized trials and meta-analyses do not exist. Such randomized trials as do exist are very few in number, are narrowly focused with small numbers, have limited general applicability, and do not lend themselves to meta-analysis because of widely divergent methodologies and different patient characteristics. Recommendations are therefore almost entirely based on non-randomized studies and relevant basic science.

  1. Computational fluid dynamics of developing avian outflow tract heart valves.

    Science.gov (United States)

    Bharadwaj, Koonal N; Spitz, Cassie; Shekhar, Akshay; Yalcin, Huseyin C; Butcher, Jonathan T

    2012-10-01

    Hemodynamic forces play an important role in sculpting the embryonic heart and its valves. Alteration of blood flow patterns through the hearts of embryonic animal models lead to malformations that resemble some clinical congenital heart defects, but the precise mechanisms are poorly understood. Quantitative understanding of the local fluid forces acting in the heart has been elusive because of the extremely small and rapidly changing anatomy. In this study, we combine multiple imaging modalities with computational simulation to rigorously quantify the hemodynamic environment within the developing outflow tract (OFT) and its eventual aortic and pulmonary valves. In vivo Doppler ultrasound generated velocity profiles were applied to Micro-Computed Tomography generated 3D OFT lumen geometries from Hamburger-Hamilton (HH) stage 16-30 chick embryos. Computational fluid dynamics simulation initial conditions were iterated until local flow profiles converged with in vivo Doppler flow measurements. Results suggested that flow in the early tubular OFT (HH16 and HH23) was best approximated by Poiseuille flow, while later embryonic OFT septation (HH27, HH30) was mimicked by plug flow conditions. Peak wall shear stress (WSS) values increased from 18.16 dynes/cm(2) at HH16 to 671.24 dynes/cm(2) at HH30. Spatiotemporally averaged WSS values also showed a monotonic increase from 3.03 dynes/cm(2) at HH16 to 136.50 dynes/cm(2) at HH30. Simulated velocity streamlines in the early heart suggest a lack of mixing, which differed from classical ink injections. Changes in local flow patterns preceded and correlated with key morphogenetic events such as OFT septation and valve formation. This novel method to quantify local dynamic hemodynamics parameters affords insight into sculpting role of blood flow in the embryonic heart and provides a quantitative baseline dataset for future research.

  2. Effect of comprehensive cardiac rehabilitation after heart valve surgery (CopenHeartVR): study protocol for a randomised clinical trial

    National Research Council Canada - National Science Library

    Sibilitz, Kirstine Laerum; Berg, Selina Kikkenborg; Hansen, Tina Birgitte; Risom, Signe Stelling; Rasmussen, Trine Bernholdt; Hassager, Christian; Køber, Lars; Steinbrüchel, Daniel; Gluud, Christian; Winkel, Per; Thygesen, Lau Caspar; Hansen, Jane Lindschou; Schmid, Jean Paul; Conraads, Viviane; Brocki, Barbara Christina; Zwisler, Ann-Dorthe

    2013-01-01

    .... We hypothesise that a comprehensive cardiac rehabilitation programme can improve physical capacity and self-assessed mental health and reduce hospitalisation and healthcare costs after heart valve surgery...

  3. Patient-specific pediatric silicone heart valve models based on 3D ultrasound

    Science.gov (United States)

    Ilina, Anna; Lasso, Andras; Jolley, Matthew A.; Wohler, Brittany; Nguyen, Alex; Scanlan, Adam; Baum, Zachary; McGowan, Frank; Fichtinger, Gabor

    2017-03-01

    PURPOSE: Patient-specific heart and valve models have shown promise as training and planning tools for heart surgery, but physically realistic valve models remain elusive. Available proprietary, simulation-focused heart valve models are generic adult mitral valves and do not allow for patient-specific modeling as may be needed for rare diseases such as congenitally abnormal valves. We propose creating silicone valve models from a 3D-printed plastic mold as a solution that can be adapted to any individual patient and heart valve at a fraction of the cost of direct 3D-printing using soft materials. METHODS: Leaflets of a pediatric mitral valve, a tricuspid valve in a patient with hypoplastic left heart syndrome, and a complete atrioventricular canal valve were segmented from ultrasound images. A custom software was developed to automatically generate molds for each valve based on the segmentation. These molds were 3D-printed and used to make silicone valve models. The models were designed with cylindrical rims of different sizes surrounding the leaflets, to show the outline of the valve and add rigidity. Pediatric cardiac surgeons practiced suturing on the models and evaluated them for use as surgical planning and training tools. RESULTS: Five out of six surgeons reported that the valve models would be very useful as training tools for cardiac surgery. In this first iteration of valve models, leaflets were felt to be unrealistically thick or stiff compared to real pediatric leaflets. A thin tube rim was preferred for valve flexibility. CONCLUSION: The valve models were well received and considered to be valuable and accessible tools for heart valve surgery training. Further improvements will be made based on surgeons' feedback.

  4. 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

    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......-time electrocardiography is seen in dogs with heart failure (HF) secondary to myxomatous mitral valve disease (MMVD). However, HRV is suggested to increase with disease severity at early stages of MMVD. The aims of this study were 1) to associate HR and HRV with severity of MMVD in Cavalier King Charles Spaniels (CKCS...

  5. 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.

  6. 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.

  7. [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.

  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. 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.

  10. 人工心脏瓣膜的研究进展%Review of Artificial Heart Valves

    Institute of Scientific and Technical Information of China (English)

    刘郁倩; 但年华; 但卫华

    2013-01-01

    Artificial heart valve was the key to treatment of valvular heart disease. The research progress of mechanical valves, bioprosthetic valves and tissue-engineering heart valves were summarized, and the problems of artificial heart valve which need to be solved and improved were noted. Then the trends of artificial heart valve in the future were prospected.%人工心脏瓣膜是治疗瓣膜性心脏病的关键。本文总结了机械瓣膜、生物瓣膜和组织工程心脏瓣膜的研究进展,并指出了人工心脏瓣膜亟待解决与提高的诸多问题,展望了人工心脏瓣膜未来的发展方向。

  11. Echocardiographic Evaluation of Hemodynamic Changes in Left-Sided Heart Valves in Pregnant Women With Valvular Heart Disease.

    Science.gov (United States)

    Samiei, Niloufar; Amirsardari, Mandana; Rezaei, Yousef; Parsaee, Mozhgan; Kashfi, Fahimeh; Hantoosh Zadeh, Sedigheh; Beikmohamadi, Somayeh; Fouladi, Masoumeh; Hosseini, Saeid; Peighambari, Mohammad Mehdi; Mohebbi, Ahmad

    2016-10-01

    Physiologic changes during pregnancy can deteriorate or improve patients' hemodynamic status in the setting of valvular heart disease. There are sparse data regarding the effect of pregnancy on valve hemodynamics in normal pregnant women with known valvular heart disease. In a prospective study from July 2014 to January 2016, a total of 52 normal pregnant women who had mitral stenosis, aortic stenosis, or a history of mitral valve or aortic valve replacements were assessed. All patients underwent echocardiographic examinations and hemodynamic parameters were measured for both the mitral valve and aortic valve at first, second, and third trimesters. The parameters included mean gradient, peak gradient, mean gradient/heart rate, peak gradient/heart rate, pressure halftime, dimensionless velocity index, and valve area. Although most hemodynamic parameters (i.e., mean gradient, peak gradient, mean gradient/heart rate, and peak gradient/heart rate) increased approximately 50% from first to second trimester and first to third trimester (p 0.05). The ratio of changes between trimesters for valve area and dimensionless velocity index were comparable. No clinical decompensations were observed except for 3 and 7 cases of deterioration to functional class II at second and third trimesters, respectively. In conclusion, during a full-term and uncomplicated pregnancy, mitral and aortic valve gradients increase without significant changes in valve area that are more marked between the second and first trimester than between the third and second trimester.

  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. Video-based measuring of quality parameters for tricuspid xenograft heart valve implants.

    Science.gov (United States)

    Condurache, Alexandru Paul; Hahn, Tobias; Scharfschwerdt, Michael; Mertins, Alfred; Aach, Til

    2009-12-01

    Defective heart valves are often replaced by implants in open-heart surgery. Both mechanical and biological implants are available. Among biological implants, xenograft ones-i.e., valves grafted from animals such as pigs, are widely used. Good implants should exhibit certain typical anatomical and functional characteristics to successfully replace the native tissue. Here, we describe a video-based system for measuring quality parameters of xenograft heart valve implants, including the area of the orifice and the fluttering of the valves' leaflets, i.e., their flaps (or cusps). Our system employs automatic methods that provide a precise and reproducible way to infer the quality of an implant. The automatic analysis of both a valve's orifice and the fluttering of its leaflets offers a more comprehensive quality assessment than current, mostly manual methods. We focus on valves with three leaflets, i.e., aortic, pulmonary, and tricuspid valves.

  14. 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.

  15. Transcatheter aortic valve implantation with the NVT Allegra transcatheter heart valve system: first-in-human experience with a novel self-expanding transcatheter heart valve.

    Science.gov (United States)

    Wenaweser, Peter; Stortecky, Stefan; Schütz, Torsten; Praz, Fabien; Gloekler, Steffen; Windecker, Stephan; Elsässer, Albrecht

    2016-05-17

    We aimed to demonstrate the feasibility and investigate the safety of a novel, self-expanding trans-catheter heart valve in a selected patient population with severe aortic stenosis. Between January and September 2013, a total of 21 patients with symptomatic severe aortic stenosis were eligible for transcatheter aortic valve implantation (TAVI) with the self-expanding NVT Allegra bioprosthesis (New Valve Technology, Hechingen, Germany) at two cardiovascular centres. Patients were elderly (age 83.8±4 years), predominantly female (95.2%), and all were considered to be at prohibitive risk for surgical aortic valve replacement (logistic EuroSCORE 30.4±11%). Procedural and device success was achieved in 95.2% and 85.7%, respectively. Echocardiographic assessment at discharge showed favourable haemodynamic results with a reduction of the mean transvalvular aortic gradient from 48.0±21 mmHg to 8.9±3 mmHg. In the majority of patients (90.5%), none or trace aortic regurgitation was recorded. Permanent pacemaker implantation was required in 23.8% of patients within the first 30 days of follow-up. Apart from one procedural death, no other serious adverse events were observed during the periprocedural period. TAVI with the NVT Allegra system was highly effective in alleviating symptoms and reducing NYHA functional class at 30-day follow-up. The first-in-human experience with the NVT Allegra transcatheter heart valve prosthesis was associated with a high rate of procedural success. Furthermore, the NVT Allegra bioprosthesis was able to achieve favourable haemodynamic results and effectively alleviate symptoms at 30-day follow-up. The larger, multicentre NAUTILUS study will provide further information on the safety and efficacy of this novel, second-generation transcatheter aortic bioprosthesis.

  16. Non-invasive imaging of prosthetic heart valves with a focus on endocarditis

    NARCIS (Netherlands)

    R.P.J. Budde (Ricardo)

    2016-01-01

    textabstractProsthetic heart valve (PHV) implantation can be a life-saving intervention. However, it does provide the patient with a lifelong chronic condition. Prosthetic heart valves can become dysfunctional due to various causes. The most dreaded complication is PHV endocarditis. Patients with a

  17. 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.

  18. 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.

  19. Living nano-micro fibrous woven fabric/hydrogel composite scaffolds for heart valve engineering.

    Science.gov (United States)

    Wu, Shaohua; Duan, Bin; Qin, Xiaohong; Butcher, Jonathan T

    2017-01-18

    Regeneration and repair of injured or diseased heart valves remains a clinical challenge. Tissue engineering provides a promising treatment approach to facilitate living heart valve repair and regeneration. Three-dimensional (3D) biomimetic scaffolds that possess heterogeneous and anisotropic features that approximate those of native heart valve tissue are beneficial to the successful in vitro development of tissue engineered heart valves (TEHV). Here we report the development and characterization of a novel composite scaffold consisting of nano- and micro-scale fibrous woven fabrics and 3D hydrogels by using textile techniques combined with bioactive hydrogel formation. Embedded nano-micro fibrous scaffolds within hydrogel enhanced mechanical strength and physical structural anisotropy of the composite scaffold (similar to native aortic valve leaflets) and also reduced its compaction. We determined that the composite scaffolds supported the growth of human aortic valve interstitial cells (HAVIC), balanced the remodeling of heart valve ECM against shrinkage, and maintained better physiological fibroblastic phenotype in both normal and diseased HAVIC over single materials. These fabricated composite scaffolds enable the engineering of a living heart valve graft with improved anisotropic structure and tissue biomechanics important for maintaining valve cell phenotypes.

  20. 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.

  1. The role of collagen cross-links in biomechanical behavior of human aortic heart valve leaflets - Relevance for tissue engineering

    NARCIS (Netherlands)

    Balguid, A.; Rubbens, M.P.; Mol, A.; Bank, R.A.; Bogers, A.J.J.C.; Kats, J.P. van; Mol, B.A.J.M. de; Baaijens, F.P.T.; Bouten, C.V.C.

    2007-01-01

    A major challenge in tissue engineering of functional heart valves is to determine and mimic the dominant tissue structures that regulate heart valve function and in vivo survival. In native heart valves, the anisotropic matrix architecture assures sustained and adequate functioning under

  2. Tricuspid Valve Regurgitation after Orthotopic Heart Transplantation: Prevalence and Etiology

    Directory of Open Access Journals (Sweden)

    Yaniv Berger

    2012-01-01

    Full Text Available Background. Tricuspid valve regurgitation (TR after orthotopic heart transplantation (OHT is common. The aims of this study were to determine the prevalence of TR after OHT, to examine the correlation between its development and various variables, and to determine its outcomes. Methods. All 163 OHT patients who were followed up between 1988 and 2009 for a minimal period of 12 months were divided into those with no TR/mild TR and those with at least mild-moderate TR, as assessed by doppler echocardiography. These groups were compared regarding preoperative hemodynamic variables, surgical technique employed, number of endomyocardial biopsies, number of acute cellular rejections, incidence of graft vasculopathy, and clinical outcomes. Results. At the end of the followup (average 8.2 years significant TR was evident in 14.1% of the patients. The development of late TR was found by univariate, but not multivariate, analysis to be significantly correlated with the biatrial surgical technique ( and the presence of graft vasculopathy (. TR development was found to be correlated with the need for tricuspid valve surgery but not with an increased mortality. Conclusions. The development of TR after OHT may be related to the biatrial anastomosis technique and to graft vasculopathy.

  3. 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....

  4. Role of concomitant tricuspid surgery in moderate functional tricuspid regurgitation in patients undergoing left heart valve surgery.

    Science.gov (United States)

    Mahesh, Balakrishnan; Wells, Francis; Nashef, Samer; Nair, Sukumaran

    2013-01-01

    Functional tricuspid regurgitation (FTR) is frequently present in patients undergoing aortic, and particularly mitral valve, surgery. Untreated FTR may lead to right heart failure. Reoperative cardiac surgery for late FTR is associated with high morbidity and mortality. Therefore, severe FTR has emerged as a Class I indication for concomitant tricuspid valve surgery in patients undergoing left valve surgery. Concomitant tricuspid valve surgery during left heart valve surgery to address moderate and mild FTR is controversial. This review addresses this issue and proposes an algorithm for the treatment of FTR in patients undergoing left heart valve surgery.

  5. The surface microstructure of cusps and leaflets in rabbit and mouse heart valves

    Directory of Open Access Journals (Sweden)

    Xia Ye

    2014-05-01

    Full Text Available In this investigation, scanning electron microscopy was used to characterize the microstructure on the surfaces of animal heart valve cusps/leaflets. The results showed that though these surfaces appear smooth to the naked eye, they are actually comprised of a double hierarchical structure consisting of a cobblestone-like microstructure and nano-cilia along with mastoids with a directional arrangement. Such nanostructures could play a very important role in the hemocompatibility characteristics of heart valves. On this basis, the model of the microstructure was constructed and theoretical analysis was used to obtain optimal geometric parameters for the rough surface of artificial valve cusps/leaflets. This model may help improve reconstructive techniques and it may be beneficial in the design and fabrication of valve substitutes or partial substitutes. Namely, the model may help ameliorate heart valve replacement surgery.

  6. Heart valve stenosis in laser spotlights: insights into a complex disease.

    Science.gov (United States)

    Büttner, Petra; Galli, Roberta; Jannasch, Anett; Schnabel, Christian; Waldow, Thomas; Koch, Edmund

    2014-01-01

    Degenerative heart valve disease is a life-threatening disease affecting about 3% of the population over 65 years. Up to date, cardiac surgery with heart valve replacement is the only available therapy. The disease is characterized by degenerative disorganization of the heart valve structure and alterations in the residing cell populations. Causes and mechanisms of disease genesis are still not fully understood and until now pharmacological therapies are not available. Thus there is enormous interest in new technologies that enable a better characterization of structure and composition of diseased valves. Currently most research techniques demand for extensive processing of extracted valve material. We present a novel approach combining coherent anti-Stokes Raman scattering, endogenous two-photon excited fluorescence and second harmonic generation. Cusp constituents can be examined simultaneously, three-dimensionally and without extensive manipulation of the sample enabling impressive insights into a complex disease.

  7. 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.

  8. Anticoagulant independent mechanical heart valves: viable now or still a distant holy grail.

    Science.gov (United States)

    Chaux, Aurelio; Gray, Richard J; Stupka, Jonathan C; Emken, Michael R; Scotten, Lawrence N; Siegel, Rolland

    2016-12-01

    Valvular heart disease remains a large public health problem for all societies; it attracts the attention of public health organizations, researchers and governments. Valve substitution is an integral part of the treatment for this condition. At present, the choice of valve prosthesis is either tissue or mechanical. Tissue valves have become increasingly popular in spite of unresolved problems with durability, hemodynamics, cost and need for anticoagulation therapy. As a consequence, mechanical valve innovation has virtually ceased; the last successful mechanical design is 25 years old. We postulate that with improved technology, knowledge and experience gained over the last quarter century, the best possible solution to the problem of valve substitution can be achieved with a mechanical valve that is anticoagulant independent, durable, hemodynamically and cost efficient. At present, it is possible to design, test and produce a valve that can accomplish these goals.

  9. Three-dimentional simulation of flow-induced platelet activation in artificial heart valves

    Science.gov (United States)

    Hedayat, Mohammadali; Asgharzadeh, Hafez; Borazjani, Iman

    2015-11-01

    Since the advent of heart valve, several valve types such as mechanical and bio-prosthetic valves have been designed. Mechanical Heart Valves (MHV) are durable but suffer from thromboembolic complications that caused by shear-induced platelet activation near the valve region. Bio-prosthetic Heart Valves (BHV) are known for better hemodynamics. However, they usually have a short average life time. Realistic simulations of heart valves in combination with platelet activation models can lead to a better understanding of the potential risk of thrombus formation in such devices. In this study, an Eulerian approach is developed to calculate the platelet activation in three-dimensional simulations of flow through MHV and BHV using a parallel overset-curvilinear immersed boundary technique. A curvilinear body-fitted grid is used for the flow simulation through the anatomic aorta, while the sharp-interface immersed boundary method is used for simulation of the Left Ventricle (LV) with prescribed motion. In addition, dynamics of valves were calculated numerically using under-relaxed strong-coupling algorithm. Finally, the platelet activation results for BMV and MHV are compared with each other.

  10. Transcatheter aortic valve replacement for bicuspid aortic stenosis 13years post heart transplant.

    Science.gov (United States)

    Julien, Maureen B; Desai, Nimesh; Brozena, Susan; Herrmann, Howard C

    2016-12-16

    Despite the widespread use of transcatheter aortic valve replacement (TAVR) for moderate and high-risk patients with severe aortic stenosis, it is utilized less frequently in patients with bicuspid aortic valves (BAV). Orthotopic heart transplant (OHT) donors tend to be younger and may have undiagnosed BAV. We present a case of successful TAVR in a patient with BAV thirteen years after OHT.

  11. 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

  12. Provision, organization and models of heart valve clinics within The United Kingdom.

    Science.gov (United States)

    Bhattacharyya, S; Pavitt, C; Lloyd, G; Chambers, J B

    2015-02-01

    Specialist clinics are recommended for the assessment and follow-up of patients with heart valve disease. We sought to identify the current provision of specialist valve clinics in UK. A database of all UK National Health Service hospitals was created. An online survey was distributed to each hospital to examine the model of heart valve clinic, patient population, provision of advanced imaging modalities and biochemical markers and provision of patient information services. Valve clinics were run in 48/228 (21%) hospitals, in 27/45 (60%) tertiary centres and 21/183 (11%) district hospitals. The survey was completed by 34 (71%). A consultant cardiologist ran the clinic in 19 (56%), a cardiac sonographer in 8 (24%), a nurse specialist in 3 (9%) and a hybrid model was used in 4 (12%). Patients with native valve disease were seen in 32 (94%), after heart valve surgery in 19 (56%), pre-/post-transcatheter valve intervention in 10 (29%) and with Marfan syndrome in 9(26%). Stress echocardiography, cardiac magnetic resonance imaging, computed tomography and positron emission tomography were available in 21 (62%), 19 (56%), 22 (65%) and 6 (18%) hospitals, respectively. There is an underprovision of specialist heart valve clinics within the UK, and there is a 5-fold difference between cardiac centres and district general hospitals. © The Author 2014. Published by Oxford University Press on behalf of the Association of Physicians. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  13. Intermittent straining accelerates the development of tissue properties in engineered heart valve tissue

    NARCIS (Netherlands)

    Rubbens, M.P.; Mol, A.; Boerboom, R.A.; Bank, R.A.; Baaijens, F.P.T.; Bouten, C.V.C.

    2009-01-01

    Tissue-engineered heart valves lack sufficient amounts of functionally organized structures and consequently do not meet in vivo mechanical demands. To optimize tissue architecture and hence improve mechanical properties, various in vitro mechanical conditioning protocols have been proposed, of

  14. Non-linear rotation-free shell finite-element models for aortic heart valves.

    Science.gov (United States)

    Gilmanov, Anvar; Stolarski, Henryk; Sotiropoulos, Fotis

    2017-01-04

    Hyperelastic material models have been incorporated in the rotation-free, large deformation, shell finite element (FE) formulation of (Stolarski et al., 2013) and applied to dynamic simulations of aortic heart valve. Two models used in the past in analysis of such problem i.e. the Saint-Venant and May-Newmann-Yin (MNY) material models have been considered and compared. Uniaxial tests for those constitutive equations were performed to verify the formulation and implementation of the models. The issue of leaflets interactions during the closing of the heart valve at the end of systole is considered. The critical role of using non-linear anisotropic model for proper dynamic response of the heart valve especially during the closing phase is demonstrated quantitatively. This work contributes an efficient FE framework for simulating biological tissues and paves the way for high-fidelity flow structure interaction simulations of native and bioprosthetic aortic heart valves. Copyright © 2016. Published by Elsevier Ltd.

  15. Hemodynamics of physiological blood flow in the aorta with nonlinear anisotropic heart valve

    Science.gov (United States)

    Sotiropoulos, Fotis; Gilmanov, Anvar; Stolarski, Henryk

    2016-11-01

    The hemodynamic blood flow in cardiovascular system is one of the most important factor, which causing several vascular diseases. We developed a new Curvilinear Immersed Boundary - Finite Element - Fluid Structure Interaction (CURVIB-FE-FSI) method to analyze hemodynamic of pulsatile blood flow in a real aorta with nonlinear anisotropic aortic valve at physiological conditions. Hyperelastic material model, which is more realistic for describing heart valve have been incorporated in the CURVIB-FE-FSI code to simulate interaction of aortic heart valve with pulsatile blood flow. Comparative studies of hemodynamics for linear and nonlinear models of heart valve show drastic differences in blood flow patterns and hence differences of stresses causing impact at leaflets and aortic wall. This work is supported by the Lillehei Heart Institute at the University of Minnesota.

  16. Exercise-based cardiac rehabilitation for adults after heart valve surgery

    DEFF Research Database (Denmark)

    Sibilitz, Kirstine Lærum; Berg, Selina Kikkenborg; Tang, Lars Hermann

    2016-01-01

    : the Cochrane Central Register of Controlled Trials (CENTRAL); the Database of Abstracts of Reviews of Effects (DARE); MEDLINE (Ovid); EMBASE (Ovid); CINAHL (EBSCO); PsycINFO (Ovid); LILACS (Bireme); and Conference Proceedings Citation Index-S (CPCI-S) on Web of Science (Thomson Reuters) on 23 March 2015. We...... handsearched Web of Science, bibliographies of systematic reviews and trial registers (ClinicalTrials.gov, Controlled-trials.com, and The World Health Organization International Clinical Trials Registry Platform). SELECTION CRITERIA: We included randomised clinical trials that investigated exercise......-based interventions compared with no exercise intervention control. The trial participants comprised adults aged 18 years or older who had undergone heart valve surgery for heart valve disease (from any cause) and received either heart valve replacement, or heart valve repair. DATA COLLECTION AND ANALYSIS: Two...

  17. Guided Tissue Regeneration in Heart Valve Replacement: From Preclinical Research to First-in-Human Trials

    OpenAIRE

    Iop, L.; Gerosa, G.

    2015-01-01

    Heart valve tissue-guided regeneration aims to offer a functional and viable alternative to current prosthetic replacements. Not requiring previous cell seeding and conditioning in bioreactors, such exceptional tissue engineering approach is a very fascinating translational regenerative strategy. After in vivo implantation, decellularized heart valve scaffolds drive their same repopulation by recipient’s cells for a prospective autologous-like tissue reconstruction, remodeling, and adaptation...

  18. 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.

  19. 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.

  20. 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.

  1. 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

    2016-01-01

    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 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.

  2. 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.

  3. 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.

  4. Simulations of heart valves by thin shells with non-linear material properties

    Science.gov (United States)

    Borazjani, Iman; Asgharzadeh, Hafez; Hedayat, Mohammadali

    2016-11-01

    The primary function of a heart valve is to allow blood to flow in only one direction through the heart. Triangular thin-shell finite element formulation is implemented, which considers only translational degrees of freedom, in three-dimensional domain to simulate heart valves undergoing large deformations. The formulation is based on the nonlinear Kirchhoff thin-shell theory. The developed method is intensively validated against numerical and analytical benchmarks. This method is added to previously developed membrane method to obtain more realistic results since ignoring bending forces can results in unrealistic wrinkling of heart valves. A nonlinear Fung-type constitutive relation, based on experimentally measured biaxial loading tests, is used to model the material properties for response of the in-plane motion in heart valves. Furthermore, the experimentally measured liner constitutive relation is used to model the material properties to capture the flexural motion of heart valves. The Fluid structure interaction solver adopts a strongly coupled partitioned approach that is stabilized with under-relaxation and the Aitken acceleration technique. This work was supported by American Heart Association (AHA) Grant 13SDG17220022 and the Center of Computational Research (CCR) of University at Buffalo.

  5. A novel technique in a sheep model for evaluating prosthetic heart valve performance.

    Science.gov (United States)

    Puc, M M; Marra, S W; Tran, H S; Cilley, J H; Hewitt, C W; DelRossi, A J

    2001-01-01

    There have been many various animal studies to evaluate the structural integrity and antithrombogenicity of prosthetic heart valves. We were interested in developing a novel sheep model to study the thrombogenicity of mechanical heart valves placed into the systemic circulation but without the need for cardiac bypass. Also, we wanted to minimize the risk ofparaplegia from complete thoracic aortic clamping. Six sheep underwent left lateral thoracotomy for placement of a mechanical heart valve in parallel with the descending thoracic aorta. A valved conduit with a dacron tube graft sutured to the back end was fashioned. Employing partial aortic occlusion with a side-biting clamp, the proximal and distal ends were anastomosed in an end-to-side fashion. Once flow was confirmed through the graft, the native aorta was occulded with umbilical tape. The sheep received no postoperative anticoagulation. The median operative time and estimated blood loss (EBL) was 170 min and 250 cc, respectively. Patency of the valved conduits was confirmed during the initial procedure, and there was no incidence of paraplegia postoperatively. Two animals expired shortly after extubation and at necropsy the valved conduits were patent with preserved valve function. The four survivors were sacrificed a median of 37 days postoperatively. Prior to euthanasia, the valved conduits were evaluated in situ with ultrasound. In all cases, the valves had clot formation at the hinges, which prevented active movement of the leaflets. This novel in vivo technique provides an alternative in testing the thrombogenicity of prosthetic heart valves without cardiac bypass or the risk of paraplegia in an animal that is extremely sensitive to complete aortic cross-clamp.

  6. 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.

  7. Prenatally engineered autologous amniotic fluid stem cell-based heart valves in the fetal circulation.

    Science.gov (United States)

    Weber, Benedikt; Emmert, Maximilian Y; Behr, Luc; Schoenauer, Roman; Brokopp, Chad; Drögemüller, Cord; Modregger, Peter; Stampanoni, Marco; Vats, Divya; Rudin, Markus; Bürzle, Wilfried; Farine, Marc; Mazza, Edoardo; Frauenfelder, Thomas; Zannettino, Andrew C; Zünd, Gregor; Kretschmar, Oliver; Falk, Volkmar; Hoerstrup, Simon P

    2012-06-01

    Prenatal heart valve interventions aiming at the early and systematic correction of congenital cardiac malformations represent a promising treatment option in maternal-fetal care. However, definite fetal valve replacements require growing implants adaptive to fetal and postnatal development. The presented study investigates the fetal implantation of prenatally engineered living autologous cell-based heart valves. Autologous amniotic fluid cells (AFCs) were isolated from pregnant sheep between 122 and 128 days of gestation via transuterine sonographic sampling. Stented trileaflet heart valves were fabricated from biodegradable PGA-P4HB composite matrices (n = 9) and seeded with AFCs in vitro. Within the same intervention, tissue engineered heart valves (TEHVs) and unseeded controls were implanted orthotopically into the pulmonary position using an in-utero closed-heart hybrid approach. The transapical valve deployments were successful in all animals with acute survival of 77.8% of fetuses. TEHV in-vivo functionality was assessed using echocardiography as well as angiography. Fetuses were harvested up to 1 week after implantation representing a birth-relevant gestational age. TEHVs showed in vivo functionality with intact valvular integrity and absence of thrombus formation. The presented approach may serve as an experimental basis for future human prenatal cardiac interventions using fully biodegradable autologous cell-based living materials. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. Twist1 directly regulates genes that promote cell proliferation and migration in developing heart valves.

    Directory of Open Access Journals (Sweden)

    Mary P Lee

    Full Text Available Twist1, a basic helix-loop-helix transcription factor, is expressed in mesenchymal precursor populations during embryogenesis and in metastatic cancer cells. In the developing heart, Twist1 is highly expressed in endocardial cushion (ECC valve mesenchymal cells and is down regulated during valve differentiation and remodeling. Previous studies demonstrated that Twist1 promotes cell proliferation, migration, and expression of primitive extracellular matrix (ECM molecules in ECC mesenchymal cells. Furthermore, Twist1 expression is induced in human pediatric and adult diseased heart valves. However, the Twist1 downstream target genes that mediate increased cell proliferation and migration during early heart valve development remain largely unknown. Candidate gene and global gene profiling approaches were used to identify transcriptional targets of Twist1 during heart valve development. Candidate target genes were analyzed for evolutionarily conserved regions (ECRs containing E-box consensus sequences that are potential Twist1 binding sites. ECRs containing conserved E-box sequences were identified for Twist1 responsive genes Tbx20, Cdh11, Sema3C, Rab39b, and Gadd45a. Twist1 binding to these sequences in vivo was determined by chromatin immunoprecipitation (ChIP assays, and binding was detected in ECCs but not late stage remodeling valves. In addition identified Twist1 target genes are highly expressed in ECCs and have reduced expression during heart valve remodeling in vivo, which is consistent with the expression pattern of Twist1. Together these analyses identify multiple new genes involved in cell proliferation and migration that are differentially expressed in the developing heart valves, are responsive to Twist1 transcriptional function, and contain Twist1-responsive regulatory sequences.

  9. 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

  10. 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

  11. 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...

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

    OpenAIRE

    D. A. Belokurov; M. L. Semenovskiy; Y. G. Moysyuk

    2013-01-01

    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 1...

  13. Blood serum apolipoproteins B and A-I in females suffering from rheumatic heart valve disease.

    Science.gov (United States)

    Stakisaitis, Donatas; Maksvytis, Arūnas; Salcius, Kestutis; Benetis, Rimantas

    2004-01-01

    With the aim to check whether the atherogenic factors are involved in the mechanisms of valve fibrosis, we have studied the blood serum concentrations of apolipoproteins (apo) A-I and B concentration in patients suffering from rheumatic heart valve fibrosis. The quantities of apoA-I and apoB in the blood serum were tested by the ELISA method. Concentration of apoA-I and B in the blood serum was determined in rheumatic females with replacement of the damaged valves: after aortic valve operation (n=11; mean age 43.3+/-3.6 years) and after mitral valve operation (n=29; 41.3+/-4.1). The results obtained for rheumatic patients were compared with the data on age-matched healthy females (n=43; 39.5+/-5.2 years). Significantly lower apoA-I level in the blood serum of all patients suffering from rheumatic heart valve disease was determined as compared with controls: in the pooled group of patients (1.02+/-0.22 vs 1.23+/-0.23 g/l, Pvalve replacement (0.98+/-0.21 vs. 1.23+/-0.23 g/l, Pvalve surgery (1.03+/-0.23 g/l vs 1.23+/-0.23 g/l, Pheart valve disease did not differ from that of controls. The apoB/apoA-I ratio for patients with valve fibrotic damage was significantly higher as compared to controls in all groups (Pvalve fibrosis was caused by lower apoA-I levels in blood serum. The obtained results indicate that decreased apoA-I levels in blood serum can be indicative of valve fibrosis in rheumatic heart valve disease patients.

  14. The Inter-Relationship of Periostin, TGFβ, and BMP in Heart Valve Development and Valvular Heart Diseases

    Directory of Open Access Journals (Sweden)

    Simon J. Conway

    2011-01-01

    Full Text Available Recent studies have suggested an important role for periostin and transforming growth factor beta (TGFβ and bone morphogenetic protein (BMP ligands in heart valve formation and valvular heart diseases. The function of these molecules in cardiovascular development has previously been individually reviewed, but their association has not been thoroughly examined. Here, we summarize the current understanding of the association between periostin and TGFβ and BMP ligands, and discuss the implications of this association in the context of the role of these molecules in heart valve development and valvular homeostasis. Information about hierarchal connections between periostin and TGFβ and BMP ligands in valvulogenesis will increase our understanding of the pathogenesis, progression, and medical treatment of human valve diseases.

  15. Classification of heart valve sounds from experiments in an anechoic water tank

    Energy Technology Data Exchange (ETDEWEB)

    Axelrod, M C; Clark, G A; Scott, D

    1999-06-01

    In vivo studies in both sheep and humans were plagued by a number of problems including movement artifacts, biological noise, low signal-to-noise ratio (SNR), chest-wall reverberation, and limited bandwidth recordings as discussed by [1]. To overcome these problems it was decided to record heart valve sounds under controlled conditions deep in an anechoic water tank, free from reverberation noise. The main goal of this experiment was to obtain measurements of ''pure'' heart valve sounds free of the scattering effects of the body. Experiments were conducted at the Transdec facility in San Diego [2]. We used a high quality hydrophone together with a wide-band data acquisition system [2]. We recorded sounds from 100 repetitions of the opening-closing cycles on each of 50 different heart valves, including 21 SLS valves and 29 intact valves. The power spectrum of the opening and closing phases of each cycle were calculated and outlier spectra removed as described by Candy [2]. In this report, we discuss the results of our classification of the heart valve sound measurements. The goal of this classification task was to apply the fundamental classification algorithms developed for the clinical data in 1994 and 1996 to the measurements from the anechoic water tank. From the beginning of this project, LLNL's responsibility has been to process and classify the heart valve sounds. For this experiment, however, we processed both the opening sounds and closing sounds for comparison purposes. The results of this experiment show that the classifier did not perform well because of low signal-to-noise ratio and excessive variability in signal power from beat-to-beat for a given valve.

  16. Supercritical carbon dioxide-based sterilization of decellularized heart valves.

    Science.gov (United States)

    Hennessy, Ryan S; Jana, Soumen; Tefft, Brandon J; Helder, Meghana R; Young, Melissa D; Hennessy, Rebecca R; Stoyles, Nicholas J; Lerman, Amir

    2017-02-01

    The goal of this research project encompasses finding the most efficient and effective method of decellularized tissue sterilization. Aortic tissue grafts have been utilized to repair damaged or diseased valves. Although, the tissues for grafting are collected aseptically, it does not eradicate the risk of contamination nor disease transfer. Thus, sterilization of grafts is mandatory. Several techniques have been applied to sterilize grafts; however, each technique shows drawbacks. In this study, we compared several sterilization techniques: supercritical carbon dioxide, electrolyzed water, gamma radiation, ethanol-peracetic acid, and hydrogen peroxide for impact on the sterility and mechanical integrity of porcine decellularized aortic valves. Valve sterility was characterized by histology, microbe culture, and electron microscopy. Uniaxial tensile testing was conducted on the valve cusps along their circumferential orientation to study these sterilization techniques on their integrity. Ethanol-peracetic acid and supercritical carbon dioxide treated valves were found to be sterile. The tensile strength of supercritical carbon dioxide treated valves (4.28 ± 0.22 MPa) was higher to those valves treated with electrolyzed water, gamma radiation, ethanol-peracetic acid and hydrogen peroxide (1.02 ± 0.15, 1.25 ± 0.25, 3.53 ± 0.41 and 0.37 ± 0.04 MPa, respectively). Superior sterility and integrity were found in the decellularized porcine aortic valves with supercritical carbon dioxide sterilization. This sterilization technique may hold promise for other decellularized soft tissues. Sterilization of grafts is essential. Supercritical carbon dioxide, electrolyzed water, gamma radiation, ethanol-peracetic acid, and hydrogen peroxide techniques were compared for impact on sterility and mechanical integrity of porcine decellularized aortic valves. Ethanol-peracetic acid and supercritical carbon dioxide treated valves were found to be sterile using histology, microbe

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

    Science.gov (United States)

    Jahnavi, S; Kumary, T V; Bhuvaneshwar, G S; Natarajan, T S; Verma, R S

    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.

  18. 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

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

    NARCIS (Netherlands)

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

    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

  20. Prosthetic valves in adult patients with congenital heart disease : Rationale and design of the Dutch PROSTAVA study

    NARCIS (Netherlands)

    Freling, H. G.; van Slooten, Y. J.; van Melle, J. P.; Mulder, B. J. M.; van Dijk, A. P. J.; Hillege, H. L.; Post, M. C.; Sieswerda, G. Tj; Jongbloed, M. R. M.; Willems, T. P.; Pieper, P. G.

    2012-01-01

    Data on long-term complications in adult patients with congenital heart disease (ACHD) and a prosthetic valve are scarce. Moreover, the influence of prosthetic valves on quality of life (QoL) and functional outcome in ACHD patients with prosthetic valves has not been studied. The primary objective o

  1. 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

  2. Prosthetic valves in adult patients with congenital heart disease: Rationale and design of the Dutch PROSTAVA study

    NARCIS (Netherlands)

    Freling, H.G.; Slooten, Y.J. van; Melle, J.P. van; Mulder, B.J.; Dijk, A.P. van; Hillege, H.L.; Post, M.C.; Sieswerda, G.T.; Jongbloed, M.R.; Willems, T.P.; Pieper, P.G.

    2012-01-01

    BACKGROUND: Data on long-term complications in adult patients with congenital heart disease (ACHD) and a prosthetic valve are scarce. Moreover, the influence of prosthetic valves on quality of life (QoL) and functional outcome in ACHD patients with prosthetic valves has not been studied. OBJECTIVES:

  3. [The assessment of mechanical heart valves stenosis in adults after aortic valve replacement: the advantage of full-flow design of mechanical valve].

    Science.gov (United States)

    Bokeria, L A; Bokeria, O L; Fadeev, A A; Makhachev, O A; Kosareva, T I; Averina, I I

    2013-01-01

    The analysis of transprosthetic hemodynamics in adults after aortic valve replacement in the Bakoulev Center for Cardiovascular Surgery in 2007-2010 demonstrated the hemodynamic advantage of the concept of new full-flow mechanical aortic valve prosthesis "CorBeat". Having the same size of internal orifice and tissue annulus diameters, the values of transprosthetic parameters (peak and mean gradients, blood flow velocities) through "CorBeat" were close to physiological values of transvalvular native aortic parameters and had a tendency to be not dependent on the size of prosthesis (p = 0.63). In the article for the first time a morphometric database of geometric values of internal orifice area of normal native aortic valves in adults was used taking into account both the gender and the body surface area's of a patient. There was also used the standardized prosthesis size Z-score which represents the number of SDs by which the internal prosthesis area differs from the mean normal native aortic valve area for the patient's body surface area. The article emphasizes the need of the personal selection of the size and the type of prosthesis for any patient as well as the need for new design development of prosthetic heart valves.

  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. A 3D velocimetry study of the flow through prosthetic heart valves

    Science.gov (United States)

    Ledesma, R.; Zenit, R.; Pulos, G.; Sanchez, E.; Juarez, A.

    2006-11-01

    Blood damage commonly appears in medical valve prothesis. It is a mayor concern for the designers and surgeons. It is well known that this damage and other complications result from the modified fluid dynamics through the replacement valve. To evaluate the performance of prosthetic heart valves, it is necessary to study the flow through them. To conduct this study , we have built a flow channel that emulates cardiac conditions and allows optical access such that a 3D-PIV velocimetry system could be used. The experiments are aimed to reconstruct the downstream structure of the flow through a mechanical and a bio-material tricuspid heart valve prothesis. Preliminary results show that the observed coherent structures can be related with haemolysis and trombosis, illnesses commonly found in valve prothesis recipients. The mean flow, the levels of strain rate and the turbulence intensity generated by the valves can also be directly related to blood damage. In general, bio-material made valves tend to reduce these complications.

  6. Incidence, Predictors, and Clinical Outcomes of Postoperative Cardiac Tamponade in Patients Undergoing Heart Valve Surgery.

    Science.gov (United States)

    You, Seng Chan; Shim, Chi Young; Hong, Geu-Ru; Kim, Darae; Cho, In Jeong; Lee, Sak; Chang, Hyuck-Jae; Ha, Jong-Won; Chang, Byung-Chul; Chung, Namsik

    2016-01-01

    This study aimed to investigate the incidence, predictors, and clinical outcomes of cardiac tamponade after heart valve surgery. A total of 556 patients who underwent heart valve surgery in a single tertiary center between January 2010 and March 2012 were studied. All patients underwent transthoracic echocardiography (TTE) about 5 days after surgery and TTE was repeated regularly. Patients with suspected acute pericardial hemorrhage were excluded. Cardiac tamponade occurred in twenty-four (4.3%) patients and all underwent surgical or percutaneous pericardial drainage. The median time of pericardial drainage after surgery was 17 (interquartile range, IQR, 13-30) days. Infective endocarditis, mechanical valve replacement of aortic or mitral valve, and any amount of pericardial effusion (PE) on the first postoperative TTE were related to the occurrence of cardiac tamponade (all ptamponade was associated with any amount of PE on the first postoperative TTE (hazard ratio, HR, 14.00, ptamponade was higher than those without (34.9 vs. 13.5, p = 0.031). After pericardial drainage, there was no echocardiographic recurrence of significant PE during a median of 34.8 (IQR 14.9-43.7) months after surgery. Cardiac tamponade after heart valve surgery is not uncommon. Patients with any amount of PE at the first postoperative TTE or mechanical valve replacement should receive higher attention with regard to the occurrence of cardiac tamponade. Although it prolongs hospital stay, cardiac tamponade exhibits a benign clinical course without recurrence after timely intervention.

  7. Relationships between melanocytes, mechanical properties and extracellular matrix composition in mouse heart valves.

    Science.gov (United States)

    Carneiro, Flavia; Kruithof, Boudewijn Pt; Balani, Kanthesh; Agarwal, Arvind; Gaussin, Vinciane; Kos, Lidia

    2015-01-01

    Heart valves are complex structures composed of organized layers of extracellular matrix, and interstitial and overlying endothelial cells. In this article, we present the specific localization of a population of melanocytes within the murine heart valves at ages important for their post-natal development. In all stages analyzed in our study, melanocytes were found in high numbers populating the atrial aspect of the tricuspid and mitral leaflets. The pulmonary valve did not present melanocytes. To characterize a putative role for the valve melanocytes, the dynamic nanomechanical properties of tricuspid leaftets containing large numbers or no melanocytes were measured. The stiffness coefficient of hyperpigmented leaflets was higher (11.5 GPa) than the ones from wild-type (7.5 GPa) and hypopigmented (5.5 GPa) leaflets. These results suggest that melanocytes may contribute to the mechanical properties of the heart valves. The arrangement of extracellular matrix molecules such as Collagen I and Versican B is responsible for the mechanical characteristics of the leaflets. Melanocytes were found to reside primarily in areas of Versican B expression. The patterns of expression of Collagen I and Versican B were not, however, disrupted in hyper or hypopigmented leaflets. Melanocytes may affect other extracellular matrix molecules to alter the valves' microenvironment.

  8. 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.

  9. Guided Tissue Regeneration in Heart Valve Replacement: From Preclinical Research to First-in-Human Trials

    Directory of Open Access Journals (Sweden)

    L. Iop

    2015-01-01

    Full Text Available Heart valve tissue-guided regeneration aims to offer a functional and viable alternative to current prosthetic replacements. Not requiring previous cell seeding and conditioning in bioreactors, such exceptional tissue engineering approach is a very fascinating translational regenerative strategy. After in vivo implantation, decellularized heart valve scaffolds drive their same repopulation by recipient’s cells for a prospective autologous-like tissue reconstruction, remodeling, and adaptation to the somatic growth of the patient. With such a viability, tissue-guided regenerated conduits can be delivered as off-the-shelf biodevices and possess all the potentialities for a long-lasting resolution of the dramatic inconvenience of heart valve diseases, both in children and in the elderly. A review on preclinical and clinical investigations of this therapeutic concept is provided with evaluation of the issues still to be well deliberated for an effective and safe in-human application.

  10. Guided tissue regeneration in heart valve replacement: from preclinical research to first-in-human trials.

    Science.gov (United States)

    Iop, L; Gerosa, G

    2015-01-01

    Heart valve tissue-guided regeneration aims to offer a functional and viable alternative to current prosthetic replacements. Not requiring previous cell seeding and conditioning in bioreactors, such exceptional tissue engineering approach is a very fascinating translational regenerative strategy. After in vivo implantation, decellularized heart valve scaffolds drive their same repopulation by recipient's cells for a prospective autologous-like tissue reconstruction, remodeling, and adaptation to the somatic growth of the patient. With such a viability, tissue-guided regenerated conduits can be delivered as off-the-shelf biodevices and possess all the potentialities for a long-lasting resolution of the dramatic inconvenience of heart valve diseases, both in children and in the elderly. A review on preclinical and clinical investigations of this therapeutic concept is provided with evaluation of the issues still to be well deliberated for an effective and safe in-human application.

  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. 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

    variability (HRV). Reduced HRV is seen in dogs with heart failure secondary to myxomatous mitral valve disease (MMVD). However, HRV is suggested to increase with disease progression in dogs with early stages of MMVD. Comparable results are found in people with primary mitral valve prolapse, a disease......Heart Rate Variability in Cavalier King Charles Spaniels with Different Degree of Myxomatous Mitral Valve Disease Rasmussen, C.E. 1, Falk, T. 1, Zois, N.E. 1, Moesgaard, S.G. 1, Häggström, J. 2, Pedersen, H.D. 3 and Olsen, L.H1. 1Department of Basic Animal and Veterinary Sciences, Faculty of Life......age. Discussion and conclusion: Most HRV variables decreased with progression of MMVD in dogs; even prior to the development of overt congestive heart failure....

  13. 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; Kikkenborg Berg, Selina

    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 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...... patient. These deviating pathways were characterized by physical, existential and mental challenges even up to 9 months after surgery. CONCLUSION: The recovery processes of participants' in cardiac rehabilitation were often more complicated than anticipated. Patients undergoing heart valve surgery may...

  14. Patient evaluation and selection for transcatheter aortic valve replacement: the heart team approach.

    Science.gov (United States)

    Sintek, Marc; Zajarias, Alan

    2014-01-01

    Transcatheter aortic valve replacement (TAVR) has been shown to significantly impact mortality and quality of life in patients with severe aortic stenosis (AS) who are deemed high risk for surgical aortic valve replacement (SAVR). Essential to these outcomes is proper patient selection. The multidisciplinary TAVR heart team was created to provide comprehensive patient evaluation and aid in proper selection. This review with outline the history and components of the heart team, and delineate the team's role in risk and frailty assessment, evaluation of common co-morbidities that impact outcomes, and the complex multi-modality imaging necessary for procedural planning and patient selection. The heart team is critical in determining patient eligibility and benefit and the optimal operative approach for TAVR. The future of structural heart disease will certainly require a team approach, and the TAVR heart team will serve as the successful model.

  15. Heart valve surgery in patients with homozygous sickle cell disease: A management strategy

    Directory of Open Access Journals (Sweden)

    El Mehdi Moutaouekkil

    2015-01-01

    Full Text Available Background: Patients with the homozygous sickle cell disease have increased perioperative mortality. Some indications like heart valve surgery, may justify an exchange blood transfusion to reduce the proportion of hemoglobin S (HbS and complications. Subjects and Methods: We report two female cases aged 20 and 27, of African origin with homozygous sickle cell anemia who underwent heart valve surgery to treat mitral valve regurgitation. This presentation describes the perioperative considerations including anesthesia and postoperative care. Results: A partial exchange blood transfusion decreased HbS levels from respectively, 90% and 84%, 9% to 27% and 34%, and simultaneously treated the anemia. Neither sickling crisis nor acidosis occurred in any patient, and no special postoperative complication occurred. Average hospital stay was 10 days. Currently, the two patients remain alive and free of cardiac symptoms. Discussion: Although the presence of sickle cell disorders is associated with increased risk of sickling and thus vaso-occlusive complications, they should not be taken as a contraindication for heart valve surgery. Nevertheless, monitoring of certain parameters such as venous, arterial oxygen content, pH, and body temperature is mandatory for a better outcome. Furthermore, preoperative exchange transfusion has a positive influence on the outcome of surgery and on the survival of patients undergoing heart valves surgery. Avoiding intraoperative hypoxia, hypothermia, and vaso-constrictive agents, minimizing HbS levels with preoperative exchange transfusion, and ensuring a stress-free environment with the judicious use of sedatives made surgery relatively safe in these cases.

  16. Serotonin receptors and heart valve disease--it was meant 2B.

    Science.gov (United States)

    Hutcheson, Joshua D; Setola, Vincent; Roth, Bryan L; Merryman, W David

    2011-11-01

    Carcinoid heart disease was one of the first valvular pathologies studied in molecular detail, and early research identified serotonin produced by oncogenic enterochromaffin cells as the likely culprit in causing changes in heart valve tissue. Researchers and physicians in the mid-1960s noted a connection between the use of several ergot-derived medications with structures similar to serotonin and the development of heart valve pathologies similar to those observed in carcinoid patients. The exact serotonergic target that mediated valvular pathogenesis remained a mystery for many years until similar cases were reported in patients using the popular diet drug Fen-Phen in the late 1990s. The Fen-Phen episode sparked renewed interest in serotonin-mediated valve disease, and studies led to the identification of the 5-HT(2B) receptor as the likely molecular target leading to heart valve tissue fibrosis. Subsequent studies have identified numerous other activators of the 5-HT(2B) receptor, and consequently, the use of many of these molecules has been linked to heart valve disease. Herein, we: review the molecular properties of the 5-HT(2B) receptor including factors that differentiate the 5-HT(2B) receptor from other 5-HT receptor subtypes, discuss the studies that led to the identification of the 5-HT(2B) receptor as the mediator of heart valve disease, present current efforts to identify potential valvulopathogens by screening for 5-HT(2B) receptor activity, and speculate on potential therapeutic benefits of 5-HT(2B) receptor targeting. Copyright © 2011. Published by Elsevier Inc.

  17. Anesthetic management of a patient with prosthetic heart valve for non-cardiac surgery: A case report.

    Science.gov (United States)

    Umesh, Goneppanavar; Verma, Swati; Jasvinder, Kaur

    2008-09-30

    Patients with prosthetic heart valves are a challenge to any anesthesiologist due to the risk of infective endocarditis, bleeding and thrombosis. We present anesthetic management of a 58-year-old Indian lady with a prosthetic (mechanical) heart valve who underwent hemireplacement arthroplasty. Patients with prosthetic heart valves, especially those with the mechanical valves are prone for thrombosis and resultant complications if anticoagulation is not maintained properly. However, when they are scheduled for major surgery, they can be best managed by normalising the coagulation profile immediately prior to surgery and restarting the anticoagulation as early as possible.

  18. 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

    not been studied. This study investigated CR programmes for these patients and factors associated with referral and participation. DESIGN AND METHODS: We distributed two nationwide surveys: one to 37 hospitals and 98 municipalities and one to 742 consecutive patients undergoing heart valve surgery. Data...... were linked to nationwide registries. We analysed the provision and content of programmes using descriptive statistics, and factors associated with referral and participation using logistic regression analysis. RESULTS: Coverage of CR programmes for these patients was high, with national programme......- and patient-level influenced uptake and included significant regional variation in referral pattern. Further research into the effect and organization of CR post heart valve surgery is needed....

  19. Favorable Effects of the Detergent and Enzyme Extraction Method for Preparing Decellularized Bovine Pericardium Scaffold for Tissue Engineered Heart Valves

    NARCIS (Netherlands)

    Yang, Min; Chen, Chang-Zhi; Wang, Xue-Ning; Zhu, Ya-Bin; Gu, Y. John

    2009-01-01

    Bovine pericardium has been extensively applied as the biomaterial for artificial heart valves and may potentially be used as a scaffold for tissue-engineered heart valves after decellularization. Although various methods of decellularization are currently available, it is unknown which method is

  20. Classification of heart valve sounds from experiments in an anechoic water tank

    Energy Technology Data Exchange (ETDEWEB)

    Axelrod, M C; Clark, G A; Scott, D

    1999-06-01

    In vivo studies in both sheep and humans were plagued by a number of problems including movement artifacts, biological noise, low signal-to-noise ratio (SNR), chest-wall reverberation, and limited bandwidth recordings as discussed by [1]. To overcome these problems it was decided to record heart valve sounds under controlled conditions deep in an anechoic water tank, free from reverberation noise, including surface reflections. Experiments were conducted in a deep water tank at the Transdec facility in San Diego, which satisfies these requirements. The Transdec measurements are free of reverberations, but not totally free of acoustic and electrical noise. We used a high quality hydrophone together with a wide-band data acquisition system [2]. We recorded sounds from 100 repetitions of the opening-closing cycles on each of 50 different heart valves, including 21 SLS valves and 29 intact valves. The power spectrum of the opening and closing phases of each cycle were calculated and outlier spectra removed as described by Candy [2]. In this report, we discuss the results of our classification of the heart valve sound measurements. The goal of this classification task was to apply the fundamental classification algorithms developed for the clinical data in 1994 and 1996 to the measurements from the anechoic water tank. From the beginning of this project, LLNL's responsibility has been to process and classify the heart valve opening sounds. For this experiment, however, we processed both the opening sounds and closing sounds for comparison purposes. The results of this experiment show that the classifier did not perform well. We believe this is because of low signal-to-noise ratio and excessive variability in signal power from beat-to-beat for a given valve.

  1. Cavitation behavior observed in three monoleaflet mechanical heart valves under accelerated testing conditions.

    Science.gov (United States)

    Lo, Chi-Wen; Liu, Jia-Shing; Li, Chi-Pei; Lu, Po-Chien; Hwang, Ned H

    2008-01-01

    Accelerated testing provides a substantial amount of data on mechanical heart valve durability in a short period of time, but such conditions may not accurately reflect in vivo performance. Cavitation, which occurs during mechanical heart valve closure when local flow field pressure decreases below vapor pressure, is thought to play a role in valve damage under accelerated conditions. The underlying flow dynamics and mechanisms behind cavitation bubble formation are poorly understood. Under physiologic conditions, random perivalvular cavitation is difficult to capture. We applied accelerated testing at a pulse rate of 600 bpm and transvalvular pressure of 120 mm Hg, with synchronized videographs and high-frequency pressure measurements, to study cavitation of the Medtronic Hall Standard (MHS), Medtronic Hall D-16 (MHD), and Omni Carbon (OC) valves. Results showed cavitation bubbles between 340 and 360 micros after leaflet/housing impact of the MHS, MHD, and OC valves, intensified by significant leaflet rebound. Squeeze flow, Venturi, and water hammer effects each contributed to cavitation, depending on valve design.

  2. 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.

  3. Fifteen-year experience with the Bicarbon heart valve prosthesis in a single center.

    Science.gov (United States)

    Misawa, Yoshio; Muraoka, Arata; Ohki, Shin-ichi; Aizawa, Kei; Kawahito, Koji; Saito, Tsutomu; Sato, Hirotaka; Takazawa, Ippei; Kurumisawa, Soki; Akutsu, Hirohiko; Sugaya, Akira

    2015-06-28

    The purpose of this study was to evaluate retrospectively the clinical performance of the Bicarbon valve (Sorin Biomedica Cardio, Saluggia, Italy) implanted at our center in Japan. Between January 1997 and December 2011, 415 patients in our institution were implanted with the Bicarbon valve. Nine of these recipients were excluded from the study because they had already undergone valve implantation and received a Bicarbon valve in a different position. The remaining patients were analyzed for evaluation of the postoperative clinical outcomes. Of the 406 patients (mean age 60.2 ± 11.7 years), 179 underwent aortic valve replacement (AVR), 149 mitral valve replacement (MVR), and 78 both aortic and mitral valve replacement (DVR). There were 10 early deaths (2.5 %: 4 in the AVR group and 6 in the MVR group). Three hundred eighty-nine patients were followed up (95.8 % completeness of follow-up) with a mean follow-up of 6.6 ± 4.2 years overall (AVR 6.8 ± 4.2, MVR, 6.7 ± 4.4, and DVR 5.7 ± 3.4 years) and a cumulative follow-up of 2661 patient-years (1214, 1001, and 446 patient-years for AVR, MVR, and DVR, respectively). Ninety-nine patients died (3.7 % per patient-year: 22 valve-related and 77 valve-unrelated deaths). Survival at 10 years was 74.1 ± 4.0 % in the AVR group, 73.7 ± 4.2 % in the MVR group, and 61.0 ± 7.9 % in the DVR group. The linearized incidence of thromboembolic complications, bleeding complications, prosthetic valve endocarditis, paravalvular leaks, and sudden death in all patients was 0.5 %, 0.5 %, 0.2 %, 0.2 %, and 0.4 % per patient-year, respectively. The incidence of valve-related complications and reoperation was 1.6 % and 0.4 %, respectively. No other valve-related complications were observed. The Bicarbon prosthetic heart valve has shown excellent clinical results and is associated with a low incidence of valve-related complications.

  4. An editorial view on the reporting of results in heart valve bioprostheses.

    Science.gov (United States)

    Del Campo, C

    1986-01-01

    Heart valve bioprostheses are most commonly analyzed as a group rather than individualized. Mechanical valves are usually referred to by specific name and manufacturer, while bioprostheses are pooled together as "tissue valves". Each specific bioprosthesis has its own structural characteristics and therefore a different level of performance and durability. Most large centers have an adequate number of these implants and a follow-up long enough to warrant separate analysis of each valve type. This review analyzes the differences among the most commonly used bioprostheses and reaffirms the reasons for their separate analysis. Authors, reviewers and editors must standardize their criteria to prevent this problem from recurring or escalating. New bioprostheses are now being released and unless we simplify their evaluation our questions will remain unanswered.

  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. Fluid-structure interaction analysis of bioprosthetic heart valves: Significance of arterial wall deformation.

    Science.gov (United States)

    Hsu, Ming-Chen; Kamensky, David; Bazilevs, Yuri; Sacks, Michael S; Hughes, Thomas J R

    2014-10-01

    We propose a framework that combines variational immersed-boundary and arbitrary Lagrangian-Eulerian (ALE) methods for fluid-structure interaction (FSI) simulation of a bioprosthetic heart valve implanted in an artery that is allowed to deform in the model. We find that the variational immersed-boundary method for FSI remains robust and effective for heart valve analysis when the background fluid mesh undergoes deformations corresponding to the expansion and contraction of the elastic artery. Furthermore, the computations presented in this work show that the arterial wall deformation contributes significantly to the realism of the simulation results, leading to flow rates and valve motions that more closely resemble those observed in practice.

  8. Heart valve replacement for patients with end-stage renal disease in Japan.

    Science.gov (United States)

    Misawa, Yoshio

    2010-08-01

    There is some controversy regarding the choice of prosthetic valves in patients with heart disease and concomitant end-stage renal disease requiring chronic dialysis. Dialysis patients tend to have a short life expectancy. In Japan, the 1-year survival of the dialysis patients was 80% in the 1980s, but exceeds 85% in the 2000s. The 5-year survival has been 54%-60% for the past 20 years. In addition, the 10-year and 15-year survivals have been 35%-42% and 23%-31%, respectively. However, in the United States, the 5-year survival had only improved to 35% among patients who started dialysis between 1996 and 2000, and the life expectancies of chronic dialysis patients in their sixth, seventh and eighth decades is 5.3-6.2 years, 3.8-4.5 years, and 2.7-3.2 years, respectively. The life expectancy of dialysis patients in Japan is thus better than that of patients in the United States. Some surgeons prefer to use bioprosthetic valves because of a high rate of hemorrhagic complications in dialysis patients. They are hesitant to use anticoagulation therapy in dialysis patients with mechanical valves. Others prefer mechanical valves because of the potential for early structural dysfunction of bioprosthetic valves implanted in the dialysis patients with abnormal calcium metabolism, which can cause calcium deposition on the bioprosthetic valves during the early postoperative period. The life expectancy of dialysis patients in Japan is relatively high. The potential risk of early calcification of bioprosthetic valves should be taken into account when choosing prosthetic heart valves for these patients in Japan.

  9. Effects of tolvaptan in the early postoperative stage after heart valve surgery: results of the STAR (Study of Tolvaptan for fluid retention AfteR valve surgery) trial.

    Science.gov (United States)

    Nishi, Hiroyuki; Toda, Koichi; Miyagawa, Shigeru; Yoshikawa, Yasushi; Fukushima, Satsuki; Kawamura, Masashi; Yoshioka, Daisuke; Saito, Tetsuya; Ueno, Takayoshi; Kuratani, Toru; Sawa, Yoshiki

    2015-12-01

    The purpose of this study was to assess the efficacy of tolvaptan, a vasopressin V2 receptor antagonist, for the management of postoperative surgical fluid retention after heart valve surgery. This was a prospective observational study of 64 patients with heart valve disease who underwent valve surgery between 2013 and 2014. Those in the tolvaptan group received tolvaptan in addition to conventional diuretic therapy. The results were compared to the results of 55 patients who underwent heart valve surgery between 2007 and 2010 and received conventional postoperative diuretics alone. The time to return to the preoperative BW was significantly shorter in the patients who received tolvaptan (6.1 ± 3.8 vs. 8.7 ± 6.7 days, p fluid retention during the early postoperative stage in cardiac surgery patients, without increased renal failure or abnormal electrolyte levels. This new type of diuretic therapy may be a suitable option for postoperative fluid management in patients undergoing cardiac surgery.

  10. 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.

  11. [Study of cytotoxicity of bioprosthetic heart valve material and its store solution].

    Science.gov (United States)

    Cheng, S; Shi, Y; Liang, W; Li, W

    1999-09-01

    This study compared the cytotoxicities of bioprosthetic heart valve materials crosslinked by glutaraldehyde, stored in 4% formaldehyde or Hank's solution. Human embryonic pulmonary fibroblasts or L-929 cell culture in vitro were used. Cell proliferative inhibition index(CP II) was calculated for bioprosthetic heart valve materials using different store methods in different rinse periods(before, 10 days, 20 days, 30 days). The results demonstrate: (1) bioprosthetic heart valve materials stored in 4% formaldehyde or in Hank's solution both have significant cytotoxicity, and the longer the rinse time continues, the lower the cytotoxicity declines; (2) HEL cell is more sensitive than L-929 cell in detecting the cytotoxicity of toxic biomaterials but for weak toxic biomaterials the two cell lines are not significanth different; (3) formatldehyde solution increases the cytotoxicity of biomaterials stored in it, but the enhanced cytotoxicity can be easily relieved by rinse. The authors conclude that bioprosthetic heart valve materials have long term significant cytotoxicity and the biomaterial cytotoxicity test using human fibroblasts is more sensitive and precise than other tests.

  12. Intermittent straining accelerates the development of tissue properties in engineered heart valve tissue

    NARCIS (Netherlands)

    Rubbens, M.P.; Mol, A.; Boerboom, R.A.; Bank, R.A.; Baaijens, F.P.T.; Bouten, C.V.C.

    2009-01-01

    Tissue-engineered heart valves lack sufficient amounts of functionally organized structures and consequently do not meet in vivo mechanical demands. To optimize tissue architecture and hence improve mechanical properties, various in vitro mechanical conditioning protocols have been proposed, of whic

  13. 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

  14. Early investigation of silver-coated Silzone heart valves prosthesis in 126 patients.

    Science.gov (United States)

    Auer, J; Berent, R; Ng, C K; Punzengruber, C; Mayr, H; Lassnig, E; Schwarz, C; Puschmann, R; Hartl, P; Eber, B

    2001-11-01

    Permanent silver (Silzone) coating of the sewing cuff of St. Jude Medical prosthetic heart valves may reduce the rate of prosthetic valve endocarditis (PVE). However, the incidence of paravalvular leaks and stroke in patients after implantation of Silzone-coated heart valve prostheses is largely unknown. Complications were analyzed among 126 consecutive patients (78 males, 48 females; mean age 64.7 years; range: 40-80 years) who received Silzone-coated prostheses at our institution between February 1998 and December 1999. Among patients, 94 had aortic valve replacement, 29 mitral valve replacement, and three had aortic and mitral valve replacement. Concomitant cardiac procedures (mainly coronary bypass) were performed in 47 patients (37.3%). Hospital mortality was 1.6% (2/126) and freedom from valve-related mortality 99.2+/-0.9%. Total follow up was 137.4 patient-years, and 98.4% complete. Strokes or transitory ischemic attacks (TIAs) occurred in four cases (two strokes, two TIAs; stroke rate 1.5%/year; 95% CI 0.4-2.6%/year; stroke+TIA rate 3%/year; 95% CI 0.4-5.25%/year). There was no case of prosthetic valve dysfunction or PVE. Freedom from reoperation due to procedure-associated complications was 97.6% (one aortic dissection, two major bleeds). Paravalvular leak was detected in 19 cases, and graded trivial or mild in 17 cases (11 grade 0-I, six grade I), and moderate in two cases (grade I-II in one, grade II in one). No patient needed reoperation due to paravalvular leak. Left ventricular (LV) function was normal in 80 cases, but was impaired mildly in 20 cases, moderately in 16, and severely in eight. Bicycle exercise testing in 92 patients (73%) showed median exercise performance (81.4+/-23.9% of normal) after correction for age and weight. Cerebral magnetic resonance imaging was performed in 64 patients (50.8%); median MRI score was 2.0+/-1.8 according to a 12-scaled score system. The overall incidence of echocardiographic paravalvular leak graded more than

  15. 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.

  16. Heart valve health, disease, replacement, and repair: a 25-year cardiovascular pathology perspective.

    Science.gov (United States)

    Schoen, Frederick J; Gotlieb, Avrum I

    2016-01-01

    The past several decades have witnessed major advances in the understanding of the structure, function, and biology of native valves and the pathobiology and clinical management of valvular heart disease. These improvements have enabled earlier and more precise diagnosis, assessment of the proper timing of surgical and interventional procedures, improved prosthetic and biologic valve replacements and repairs, recognition of postoperative complications and their management, and the introduction of minimally invasive approaches that have enabled definitive and durable treatment for patients who were previously considered inoperable. This review summarizes the current state of our understanding of the mechanisms of heart valve health and disease arrived at through innovative research on the cell and molecular biology of valves, clinical and pathological features of the most frequent intrinsic structural diseases that affect the valves, and the status and pathological considerations in the technological advances in valvular surgery and interventions. The contributions of many cardiovascular pathologists and other scientists, engineers, and clinicians are emphasized, and potentially fruitful areas for research are highlighted. Copyright © 2016 Elsevier Inc. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Siddharth Wartak

    2016-01-01

    Full Text Available 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.

  18. Computational Modeling of Blood Flow and Valve Dynamics in Hearts with Hypertrophic Cardiomyopathy

    Science.gov (United States)

    Zheng, Xudong; Mittal, Rajat; Abraham, Theodore; Pinheiro, Aurelio

    2010-11-01

    Hypertrophic Cardiomyopathy (HCM) is a cardiovascular disease manifested by the thickening of the ventricular wall and often leads to a partial obstruction to the blood flow out of the left ventricle. HCM is recognized as one of the most common causes of sudden cardiac death in athletes. In a heart with HCM, the hypertrophy usually narrows the blood flow pathway to the aorta and produces a low pressure zone between the mitral valve and the hypertrophy during systole. This low pressure can suck the mitral valve leaflet back and completely block the blood flow into the aorta. In the current study, a sharp interface immersed boundary method flow solver is employed to study the hemodynamics and valve dynamics inside a heart with HCM. The three-dimensional motion and configuration of the left ventricle including mitral valve leaflets and aortic valves are reconstructed based on echo-cardio data sets. The mechanisms of aortic obstruction associated with HCM are investigated. The long term objective of this study is to develop a computational tool to aid in the assessment and surgical management of HCM.

  19. 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

  20. 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.

  1. 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.

  2. Rheumatic Heart Disease and Myxomatous Degeneration: Differences and Similarities of Valve Damage Resulting from Autoimmune Reactions and Matrix Disorganization

    Science.gov (United States)

    Martins, Carlo de Oliveira; Demarchi, Lea; Ferreira, Frederico Moraes; Pomerantzeff, Pablo Maria Alberto; Brandao, Carlos; Sampaio, Roney Orismar; Spina, Guilherme Sobreira; Kalil, Jorge; Cunha-Neto, Edecio

    2017-01-01

    Autoimmune inflammatory reactions leading to rheumatic fever (RF) and rheumatic heart disease (RHD) result from untreated Streptococcus pyogenes throat infections in individuals who exhibit genetic susceptibility. Immune effector mechanisms have been described that lead to heart tissue damage culminating in mitral and aortic valve dysfunctions. In myxomatous valve degeneration (MXD), the mitral valve is also damaged due to non-inflammatory mechanisms. Both diseases are characterized by structural valve disarray and a previous proteomic analysis of them has disclosed a distinct profile of matrix/structural proteins differentially expressed. Given their relevance in organizing valve tissue, we quantitatively evaluated the expression of vimentin, collagen VI, lumican, and vitronectin as well as performed immunohistochemical analysis of their distribution in valve tissue lesions of patients in both diseases. We identified abundant expression of two isoforms of vimentin (45 kDa, 42 kDa) with reduced expression of the full-size protein (54 kDa) in RHD valves. We also found increased vitronectin expression, reduced collagen VI expression and similar lumican expression between RHD and MXD valves. Immunohistochemical analysis indicated disrupted patterns of these proteins in myxomatous degeneration valves and disorganized distribution in rheumatic heart disease valves that correlated with clinical manifestations such as valve regurgitation or stenosis. Confocal microscopy analysis revealed a diverse pattern of distribution of collagen VI and lumican into RHD and MXD valves. Altogether, these results demonstrated distinct patterns of altered valve expression and tissue distribution/organization of structural/matrix proteins that play important pathophysiological roles in both valve diseases. PMID:28121998

  3. Inner ventricular structures and valves of the heart in white rhinoceros (Ceratotherium simum).

    Science.gov (United States)

    Erdoğan, Serkan; Lima, Martin; Pérez, William

    2014-01-01

    In this study, we describe the internal structures of both ventricles and the valvular apparatus of the heart of the white rhino. In the right of the heart, three papillary muscles were found in septal and marginal walls and m. papillaris magnus was the biggest. There was only one m. papillaris parvus in the right ventricle. The right atrioventricular valve was tricuspid, and the parietal cusp was longest. In the left of the heart, two papillary muscles were found on the septal wall and the subauricular was the biggest. The left atrioventricular valve was bicuspid and the parietal cusp was longest. There were no nodules in the valves of the pulmonary trunk and aorta, and the semilunar valves had many fibrous folds and transparent parts. Within the cardiac skeleton there was a cartilago cordis which occupied a small part of the right fibrous trigone. While the right ventricle included only one septomarginal trabecula, there were many trabeculae in the left ventricle. In both ventricles, the endocardium was thin and the subendocardial network was visible, also their continuation with the septomarginal trabeculae. We also found many trabeculae carneae in the dorsal part of the ventricles.

  4. [Combined surgical treatment for coronary heart disease as well as heart valve diseases and carotid artery stenosis].

    Science.gov (United States)

    Reichart, B; Kemkes, B M; Klinner, W; Kreuzer, E; Becker, H M; Harrington, O B; Crosby, V G; Wolf, R Y

    1979-04-26

    This is an account on combined procedures in 124 patients suffering from arteriosclerotic vessel disease. In order to judge the proceedings and the results the patients were divided up into two groups. in 15 patients (group I) a carotid endarterectomy combined with an aorto-coronary bypass operation was performed; once a subclavian artery stenosis was resected at the same time. One patient of that group died after 31 days (7%). In group II 108 heart valve operations were performed together with a coronary artery revascularisation. Early and late mortality divided up as follows: aortic stenosis 6/44 (14%) respectively 2/44 (5%); aortic insufficiency 1/14 (7%) resp. 0; combined aortic disease 1/8 )13%) resp. 0; mitral stenosis 1/11 (9%) resp. 0; mitral insufficiency 6/26 (23%) resp. 2/26 (8%); combined mitral valve disease 1/2 (50%) resp. 0; three times both valves (aorta, mitral) were replaced without mortality. In our opinion combined procedures, resection of supraaortic artery stenosis respectively cardiac valve operations and aorto-coronary bypass are indicated especially since the functional long-term results are excellent. Though one should consider the high operative risk in patients with mitral insufficiency and combined mitral valve disease.

  5. 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.

  6. 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.

  7. 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

  8. 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

  9. 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.

  10. The incidence of transcatheter aortic valve implantation-related heart block in self-expandable Medtronic CoreValve and balloon-expandable Edwards valves.

    Science.gov (United States)

    Liang, Michael; Devlin, Gerard; Pasupati, Sanjeevan

    2012-04-01

    Transcatheter aortic valve implantation (TAVI) has been performed at Waikato Hospital for high-risk severe symptomatic aortic stenosis patients who are considered unsuitable for conventional cardiac surgery for the last 3 years. The Medtronic CoreValve (MCV) is a self-expandable device, while the Edwards SAPIEN valve (EV) requires the use of a balloon to expand the device. This observational study reports and compares the incidence of heart block in both Medtronic and Edwards transcatheter valves. All patients who underwent TAVI between the periods of 28 August 2008 and 27 July 2011 were included in this study. Preprocedure and daily postprocedure until discharge electrocardiograms (ECG) were obtained prospectively. New onsets of significant atrioventricular (AV) and bundle branch blocks were recorded. Patients with existing pacemaker and those who did not survive the procedure were excluded. Sixty patients underwent TAVI during the study period, of whom 40 (67%) and 20 (33%) patients had MCV and EV implanted, respectively. Seven patients were excluded from the analysis; 38 MCV and 15 EV patients fulfilled the criteria for analysis. Mean age was 80 ± 7 years, 57% were male. Five patients (9%) required permanent pacemaker (PPM) implantation, which occurred exclusively post MCV TAVI (MCV vs EV: 13% vs 0%, respectively; P=.02). The indications of PPM were complete heart block in 3 patients (60%), Mobitz II second-degree heart block in 1 patient (20%), and symptomatic sick sinus syndrome in 1 patient (20%). The incidence of left bundle branch block (LBBB) was increased after the TAVI procedure and was more significant with MCV implants (MCV vs EV: 42% vs 8%, respectively; P<.01). Of note, 2 of the 5 patients (40%) with pre-existing right bundle branch block (RBBB) who underwent TAVI required PPM (P=.01). MCV implantation is associated with a higher incidence of significant AV block requiring PPM implantation and LBBB compared to EV. The overall rate of PPM requirement

  11. 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

  12. Biodegradable and biomimetic elastomeric scaffolds for tissue-engineered heart valves.

    Science.gov (United States)

    Xue, Yingfei; Sant, Vinayak; Phillippi, Julie; Sant, Shilpa

    2017-01-15

    Valvular heart diseases are the third leading cause of cardiovascular disease, resulting in more than 25,000 deaths annually in the United States. Heart valve tissue engineering (HVTE) has emerged as a putative treatment strategy such that the designed construct would ideally withstand native dynamic mechanical environment, guide regeneration of the diseased tissue and more importantly, have the ability to grow with the patient. These desired functions could be achieved by biomimetic design of tissue-engineered constructs that recapitulate in vivo heart valve microenvironment with biomimetic architecture, optimal mechanical properties and possess suitable biodegradability and biocompatibility. Synthetic biodegradable elastomers have gained interest in HVTE due to their excellent mechanical compliance, controllable chemical structure and tunable degradability. This review focuses on the state-of-art strategies to engineer biomimetic elastomeric scaffolds for HVTE. We first discuss the various types of biodegradable synthetic elastomers and their key properties. We then highlight tissue engineering approaches to recreate some of the features in the heart valve microenvironment such as anisotropic and hierarchical tri-layered architecture, mechanical anisotropy and biocompatibility.

  13. 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

    Objectives: After transcatheter aortic valve implantation (TAVI) has been available for high-risk patients with severe aortic valve stenosis (AVS), the decision-making of the Heart Team (HT) has not been examined. Design: All adult patients with severe AVS referred to a large tertiary medical......%), 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 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...

  14. In vitro susceptibility of high virulence microorganisms isolated in heart valve banking.

    Science.gov (United States)

    Villalba, R; Solis, F; Fornés, G; Jimenez, A; Eisman, M; González, Ana I; Linares, M J; Casal, M; Gómez Villagrán, J L

    2012-08-01

    Storage preparation of human heart valves for implants generally includes incubation in an antimicrobial disinfection solution and cryopreservation. Changes in patterns of microorganisms susceptibility to antibiotics is a variable process of that promote its inefficiency. The aim of this study has been an evaluation of in vitro susceptibility of high virulence microorganisms isolated in our tissue bank for 14 years in order to evaluate the efficiency, and to promote changes for further antibiotics mixtures as well. Data presented in this study show that microorganisms isolates in valve banking display susceptibility patterns similar to those shown in other clinical circumstances, and the most commonly used antibiotics regimes are useful to date. An antibiotic cocktail containing aminoglicoside in addition to ciprofloxacin and vancomycin is an efficient mixture to be used in valve banking. Further studies will be necessary for monitoring patterns changes of in vitro susceptibility of microbiological isolates in tissue banking.

  15. 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.

  16. Porcine vena cava as an alternative to bovine pericardium in bioprosthetic percutaneous heart valves.

    Science.gov (United States)

    Munnelly, Amy E; Cochrane, Leonard; Leong, Joshua; Vyavahare, Naren R

    2012-01-01

    Percutaneous heart valves are revolutionizing valve replacement surgery by offering a less invasive treatment option for high-risk patient populations who have previously been denied the traditional open chest procedure. Percutaneous valves need to be crimped to accommodate a small-diameter catheter during deployment, and they must then open to the size of heart valve. Thus the material used must be strong and possess elastic recoil for this application. Most percutaneous valves utilize bovine pericardium as a material of choice. One possible method to reduce the device delivery diameter is to utilize a thin, highly elastic tissue. Here we investigated porcine vena cava as an alternative to bovine pericardium for percutaneous valve application. We compared the structural, mechanical, and in vivo properties of porcine vena cava to those of bovine pericardium. While the extracellular matrix fibers of pericardium are randomly oriented, the vena cava contains highly aligned collagen and elastin fibers that impart strength to the vessel in the circumferential direction and elasticity in the longitudinal direction. Moreover, the vena cava contains a greater proportion of elastin, whereas the pericardium matrix is mainly composed of collagen. Due to its high elastin content, the vena cava is significantly less stiff than the pericardium, even after crosslinking with glutaraldehyde. Furthermore, the vena cava's mechanical compliance is preserved after compression under forces similar to those exerted by a stent, whereas pericardium is significantly stiffened by this process. Bovine pericardium also showed surface cracks observed by scanning electron microscopy after crimping that were not seen in vena cava tissue. Additionally, the vena cava exhibited reduced calcification (46.64 ± 8.15 μg Ca/mg tissue) as compared to the pericardium (86.79 ± 10.34 μg/mg). These results suggest that the vena cava may provide enhanced leaflet flexibility, tissue resilience, and tissue

  17. Twenty-year single-center experience with the medtronic open pivot mechanical heart valve.

    Science.gov (United States)

    Van Nooten, Guido J; Bové, Thierry; Van Belleghem, Yves; François, Katrien; Caes, Frank; Vandenplas, Guy; De Pauw, Michel; Taeymans, Yves

    2014-04-01

    Since May 1992 the Medtronic Open Pivot mechanical heart valve has been implanted routinely at the authors' institution. The study aim was to analyze, retrospectively, the 20-year clinical results of the valve. Between May 1992 and December 2011 a total of 1,520 valves was inserted into 1,382 consecutive patients (1,012 aortic, 473 mitral, 26 tricuspid, 9 pulmonary). The mean age of the patients was 61±13.2 years. Preoperatively, 65% of the patients were in New York Heart Association (NYHA) class III or greater. Frequent comorbidities included atrial fibrillation (n=419), coronary disease (n=357), and diabetes (n=255). The 99% complete follow-up totaled 10,527 patient-years (range 12 to 244 months). Ninety-day mortality was 5.2% (n=73, 8 valve related). Of the 550 total deaths, 240 were cardiac and 56 valve related. Multivariate analysis selected age, NYHA III or greater, concomitant coronary revascularization, and respiratory insufficiency as risk factors for death. Renal failure was considered a risk factor in the aortic and atrial fibrillation in the mitral subgroup. Erratic international normalized ratio (INR), NYHA class III or greater, and non-sinus rhythm were risk factors for thromboembolism; likewise redo operations in the aortic subgroup. Erratic INR and age were risk factors for bleeding as were over-coagulation and coronary revascularization in the aortic subgroup and redo operations and renal failure in mitral patients. This 20-year experience demonstrated excellent clinical outcomes with no structural valve failure. Odds ratio defined aortic patients as the lowest risk for adverse events. By contrast atrial fibrillation and elderly age, in combination with instable anticoagulation, yielded the worst long-term results. Copyright © 2014 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  18. 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

  19. Sleep-Disordered Breathing in Patients with Pulmonary Valve Incompetence Complicating Congenital Heart Disease.

    Science.gov (United States)

    Miles, Susan; Ahmad, Waheed; Bailey, Amy; Hatton, Rachael; Boyle, Andrew; Collins, Nicholas

    2016-12-01

    Long standing pulmonary regurgitation results in deleterious effects on right heart size and function with late consequences of right heart volume overload including ventricular dilatation, propensity to arrhythmia and right heart failure. As sleep disordered breathing may predispose to elevations in pulmonary vascular resistance and associated negative effects on right ventricular function, we sought to assess this in patients with underlying congenital heart disease. We performed a pilot study to evaluate the incidence of sleep-disordered breathing in a patient population with a history of long standing pulmonary valve incompetence in patients with congenital heart disease using overnight oximetry. Patients with a background of tetralogy of Fallot repair or residual pulmonary incompetence following previous pulmonary valve intervention for congenital pulmonary stenosis were included. Twenty-two patients underwent overnight oximetry. The mean age of the cohort was 34.3 ± 15.2 years with no patients observed to have severe underlying pulmonary hypertension. Abnormal overnight oximetry was seen in 13/22 patients (59.1%) with 2/22 (9.1%) patients considered to have severe abnormalities. An important proportion of patients with a background of pulmonary incompetence complicating congenital heart disease are prone to the development of sleep-disordered breathing as assessed by overnight oximetry. Further study into the prevalence and mechanisms of sleep-disordered breathing in a larger cohort are warranted. © 2016 Wiley Periodicals, Inc.

  20. Genes in congenital heart disease: atrioventricular valve formation.

    NARCIS (Netherlands)

    Joziasse, I.C.; van de Smagt, J.J.; Smith, K.; Bakkers, J.; Sieswerda, G.J.; Mulder, B.J.M.; Doevendans, P.A.

    2008-01-01

    Through the use of animal studies, many candidate genes (mainly encoding transcriptional factors and receptors) have been implicated in the development of congenital heart disease. Thus far, only a minority of these genes have been shown to carry mutations associated with congenital disease in human

  1. 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

  2. Engineering of a bio-functionalized hybrid off-the-shelf heart valve.

    Science.gov (United States)

    Hinderer, Svenja; Seifert, Jan; Votteler, Miriam; Shen, Nian; Rheinlaender, Johannes; Schäffer, Tilman E; Schenke-Layland, Katja

    2014-02-01

    Currently available heart valve replacements are limited in long-term performance or fail due to leaflet thickening, lack of growth or remodeling potential. In order to address these issues, it is necessary to mimic multiple factors of the native valvular extracellular matrix (ECM) such as architecture, mechanical behavior and biochemical signals. Here, we successfully generated an electrospun PEGdma-PLA scaffold adapted to the structure and mechanical properties of native valve leaflets. Valvular interstitial cells (VICs) and valvular endothelial cells (VECs) were seeded on the scaffold and when cultured under physiological conditions in a bioreactor, the construct performed like a native leaflet. Atomic force microscopy (AFM) was employed to obtain detailed mechanical information from the leaflets, which enabled the first layer-specific measurement of the Young's modulus. Interestingly, spongiosa stiffness was much lower compared to the fibrosa and ventricularis. Moreover, investigations into human fetal heart valve development identified collagen type I and versican as important structural proteins. As a proof of principle, these proteins were introduced to the scaffold, demonstrating the ability to bio-functionalize the hybrid valve based on natures' blueprint.

  3. Time-Resolved Micro PIV in the Pivoting Area of the Triflo Mechanical Heart Valve.

    Science.gov (United States)

    Vennemann, Bernhard M; Rösgen, Thomas; Carrel, Thierry P; Obrist, Dominik

    2016-09-01

    The Lapeyre-Triflo FURTIVA valve aims at combining the favorable hemodynamics of bioprosthetic heart valves with the durability of mechanical heart valves (MHVs). The pivoting region of MHVs is hemodynamically of special interest as it may be a region of high shear stresses, combined with areas of flow stagnation. Here, platelets can be activated and may form a thrombus which in the most severe case can compromise leaflet mobility. In this study we set up an experiment to replicate the pulsatile flow in the aortic root and to study the flow in the pivoting region under physiological hemodynamic conditions (CO = 4.5 L/min / CO = 3.0 L/min, f = 60 BPM). It was found that the flow velocity in the pivoting region could reach values close to that of the bulk flow during systole. At the onset of diastole the three valve leaflets closed in a very synchronous manner within an average closing time of 55 ms which is much slower than what has been measured for traditional bileaflet MHVs. Hot spots for elevated viscous shear stresses were found at the flanges of the housing and the tips of the leaflet ears. Systolic VSS was maximal during mid-systole and reached levels of up to 40 Pa.

  4. Identification of critical zones in the flow through prosthetic heart valves

    Science.gov (United States)

    Lopez, A.; Ledesma, R.; Zenit, R.; Pulos, G.

    2008-11-01

    The hemodynamic properties of prosthetic heart valves can cause blood damage and platelet activation due to the non- physiological flow patterns. Blood recirculation and elevated shear stresses are believed to be responsible for these complications. The objective of this study is to identify and quantify the conditions for which recirculation and high stress zones appear. We have performed a comparative study between a mechanical monoleaflet and biological valve. In order to generate the flow conditions to test the prosthesis, we have built a hydraulic circuit which reproduces the human systemic circulation, on the basis of the Windkessel model. This model is based on an electrical analogy which consists of an arterial resistance and compliance. Using PIV 3D- Stereo measurements, taken downstream from the prosthetic heart valves, we have reconstructed the full phase-averaged tridimensional velocity field. Preliminary results show that critical zones are more prominent in mechanical prosthesis, indicating that valves made with bio-materials are less likely to produce blood trauma. This is in accordance with what is generally found in the literature.

  5. 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

  6. Fluid-structure interaction in the left ventricle of the human heart coupled with mitral valve

    Science.gov (United States)

    Meschini, Valentina; de Tullio, Marco Donato; Querzoli, Giorgio; Verzicco, Roberto

    2016-11-01

    In this paper Direct Numerical Simulations (DNS), implemented using a fully fluid-structure interaction model for the left ventricle, the mitral valve and the flowing blood, and laboratory experiments are performed in order to cross validate the results. Moreover a parameter affecting the flow dynamics is the presence of a mitral valve. We model two cases, one with a natural mitral valve and another with a prosthetic mechanical one. Our aim is to understand their different effects on the flow inside the left ventricle in order to better investigate the process of valve replacement. We simulate two situations, one of a healthy left ventricle and another of a failing one. While in the first case the flow reaches the apex of the left ventricle and washout the stagnant fluid with both mechanical and natural valve, in the second case the disturbance generated by the mechanical leaflets destabilizes the mitral jet, thus further decreasing its capability to penetrate the ventricular region and originating heart attack or cardiac pathologies in general.

  7. Prosthetic heart valve assessment with multidetector-row CT: imaging characteristics of 91 valves in 83 patients

    Energy Technology Data Exchange (ETDEWEB)

    Habets, Jesse; Mali, Willem P.T.M.; Budde, Ricardo P.J. [UMC Utrecht, Department of Radiology, P.O. Box 85500, E01.132, GA, Utrecht (Netherlands); Symersky, Petr [Onze Lieve Vrouwe Gasthuis, Department of Cardiothoracic Surgery, Amsterdam (Netherlands); Academic Medical Center Amsterdam, Department of Cardiothoracic Surgery, Amsterdam (Netherlands); Herwerden, Lex A. van [University Medical Center Utrecht, Department of Cardiothoracic Surgery, Utrecht (Netherlands); Mol, Bas A.J.M. de [Academic Medical Center Amsterdam, Department of Cardiothoracic Surgery, Amsterdam (Netherlands); Spijkerboer, Anje M. [Academic Medical Center Amsterdam, Department of Radiology, Amsterdam (Netherlands)

    2011-07-15

    Multidetector CT (MDCT) has shown potential for prosthetic heart valve (PHV) assessment. We assessed the image quality of different PHV types to determine which valves are suitable for MDCT evaluation. All ECG-gated CTs performed in our institutions since 2003 were reviewed for the presence of PHVs. After reconstruction in 3 specific PHV planes, image quality of the supravalvular, perivalvular, subvalvular and valvular regions was scored on a four-point scale (1 = non-diagnostic, 2 = moderate, 3 = good and 4 = excellent) by two independent observers. Eighty-four CT examinations (66 cardiac, 18 limited-dose aortic protocols) of 83 patients with a total of 91 PHVs in the aortic (n = 71), mitral (n = 17), pulmonary (n = 1) and tricuspid (n = 2) position were included. CT was performed on a 16-slice (n = 4), 64-slice (n = 28) or 256-slice (n = 52) MDCT system. Median image quality scores for the supra-, peri- and subvalvular regions and valvular detail were (3.5, 3.3, 3.5 and 3.5, respectively) for bileaflet PHV; (3.0, 3.0, 3.5 and 3.0, respectively) for Medtronic Hall PHV; (1.0, 1.0, 1.0 and 1.0, respectively) for Bjoerk-Shiley and Sorin monoleaflet PHV and (3.5, 3.5, 4.0 and 2.0 respectively) for biological PHV. Currently implanted PHVs have good image quality on MDCT and are suitable for MDCT evaluation. (orig.)

  8. Fluid-structure interaction modeling of aortic valve stenosis at different heart rates.

    Science.gov (United States)

    Bahraseman, Hamidreza Ghasemi; Languri, Ehsan Mohseni; Yahyapourjalaly, Niloofar; Espino, Daniel M

    2016-01-01

    This paper proposes a model to measure the cardiac output and stroke volume at different aortic stenosis severities using a fluid-structure interaction (FSI) simulation at rest and during exercise. The geometry of the aortic valve is generated using echocardiographic imaging. An Arbitrary Lagrangian-Eulerian mesh was generated in order to perform the FSI simulations. Pressure loads on ventricular and aortic sides were applied as boundary conditions. FSI modeling results for the increment rate of cardiac output and stroke volume to heart rate, were about 58.6% and -14%, respectively, at each different stenosis severity. The mean gradient of curves of cardiac output and stroke volume to stenosis severity were reduced by 57% and 48%, respectively, when stenosis severity varied from healthy to critical stenosis. Results of this paper confirm the promising potential of computational modeling capabilities for clinical diagnosis and measurements to predict stenosed aortic valve parameters including cardiac output and stroke volume at different heart rates.

  9. 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.

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

    Directory of Open Access Journals (Sweden)

    Daphne van Geemen

    Full Text Available 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.

  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. Impact of atrial remodeling on heart rhythm after radiofrequency ablation and mitral valve operations.

    Science.gov (United States)

    Olasinska-Wisniewska, Anna; Mularek-Kubzdela, Tatiana; Grajek, Stefan; Marszalek, Andrzej; Sarnowski, Wojciech; Jemielity, Marek; Seniuk, Wojciech; Lesiak, Maciej; Prech, Marek; Podzerek, Tomasz

    2012-05-01

    This study was conducted to determine the effect of left atrial structural remodeling on heart rhythm after radiofrequency ablation concomitant to mitral valve operation. Sixty-six consecutive patients with of atrial fibrillation (AF) and mitral valve disease underwent radiofrequency ablation and mitral valve operation. Heart rhythm was evaluated before and at 3, 6, and 12 months postoperatively. Biopsy specimens of the posterior wall of the left atrium were evaluated for the extent of fibrosis, myocyte diameter, intensity of inflammatory infiltrates, degree of myocytolysis, and capillary density. Ten patients died and 1 patient was lost to follow-up. Heart rhythm at 12 months was used to divide the remaining 55 patients into two groups: group I, 34 with sinus rhythm; group II, 21 with AF. Paroxysmal AF preoperatively was more frequent among group I patients, and persistent/long-standing persistent AF in group II (p=0.0006). Groups I and II differed significantly in myocyte diameter (17.9±3.5 vs 20.3±4.6 μm, p=0.04), fibrosis percentage (38.7%±11.2% vs 47.6%±12.3%, p=0.009), inflammatory infiltrates (p=0.02), and preoperative left atrial diameter (5.03±0.7 vs 5.5±0.8 cm, p=0.04). No differences were found in capillary density (797.9±500.6 vs 946.0±373.7/mm2, p=0.3) and myocytolysis (p=0.4). Multivariate analysis showed myocyte diameter (p=0.047) and fibrosis (p=0.014) were independent predictors for an AF persistence at 12 months. Left atrial structural remodeling strongly affects heart rhythm after concomitant radiofrequency ablation and mitral valve operation. Copyright © 2012 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

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

    Energy Technology Data Exchange (ETDEWEB)

    Ye Xia [Center of Photonics Fabrication, Jiangsu University, Zhenjiang 212013 (China); School of Mechanical Engineering, Jiangsu Teachers University of Technology, Changzhou 213015 (China); Shao Yunliang [Center of Photonics Fabrication, Jiangsu University, Zhenjiang 212013 (China); Zhou Ming, E-mail: zm_laser@126.com [Center of Photonics Fabrication, Jiangsu University, Zhenjiang 212013 (China); Li Jian; Cai Lan [Center of Photonics Fabrication, Jiangsu University, Zhenjiang 212013 (China)

    2009-04-15

    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 {mu}m in underside diameter and 3 {mu}m 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.

  14. Experimental Validation of a Cardiac Simulator for in vitro Evaluation of Prosthetic Heart Valves

    Directory of Open Access Journals (Sweden)

    Ovandir Bazan

    Full Text Available Abstract Objective: This work describes the experimental validation of a cardiac simulator for three heart rates (60, 80 and 100 beats per minute, under physiological conditions, as a suitable environment for prosthetic heart valves testing in the mitral or aortic position. Methods: In the experiment, an aortic bileaflet mechanical valve and a mitral bioprosthesis were employed in the left ventricular model. A test fluid of 47.6% by volume of glycerin solution in water at 36.5ºC was used as blood analogue fluid. A supervisory control and data acquisition system implemented previously in LabVIEW was applied to induce the ventricular operation and to acquire the ventricular signals. The parameters of the left ventricular model operation were based on in vivo and in vitro data. The waves of ventricular and systemic pressures, aortic flow, stroke volume, among others, were acquired while manual adjustments in the arterial impedance model were also established. Results: The acquired waves showed good results concerning some in vivo data and requirements from the ISO 5840 standard. Conclusion: The experimental validation was performed, allowing, in future studies, characterizing the hydrodynamic performance of prosthetic heart valves.

  15. Familial TAB2 microdeletion and congenital heart defects including unusual valve dysplasia and tetralogy of fallot.

    Science.gov (United States)

    Weiss, Karin; Applegate, Carolyn; Wang, Tao; Batista, Denise A S

    2015-11-01

    Haploinsufficiency of TAB2 was recently implicated as a cause for a variety of congenital heart defects. Reported cases have genomic deletions of 2-10 Mbs including TAB2 at 6q24-25 are almost always de novo and show variable cardiac and extra cardiac phenotype. We report on an inherited, 281 kb deletion in a three generation family. This is the smallest reported deletion involving TAB2 that segregates with congenital heart defects. Three affected individuals in this family present with myxomatous cardiac valves in addition to structural heart defects commonly associated with TAB2 deletions. Findings from this family support a key role of TAB2 haploinsufficiency in congenital heart defects and expand the phenotypic spectrum of TAB2-microdeletion syndrome. © 2015 Wiley Periodicals, Inc.

  16. Stroke prevention strategies in patients with atrial fibrillation and heart valve abnormalities: perceptions of 'valvular' atrial fibrillation: results of the European Heart Rhythm Association Survey.

    Science.gov (United States)

    Potpara, Tatjana S; Lip, Gregory Y H; Larsen, Torben B; Madrid, Antonio; Dobreanu, Dan; Jędrzejczyk-Patej, Ewa; Dagres, Nikolaos

    2016-10-01

    The purpose of this European Heart Rhythm Association (EHRA) Survey was to assess the perceptions of 'valvular' atrial fibrillation (AF) and management of AF patients with various heart valve abnormalities in daily clinical practice in European electrophysiology (EP) centres. Questionnaire survey was sent via the Internet to the EHRA-EP Research Network Centres. Of the 52 responding centres, 42 (80.8%) were university hospitals. Choosing the most comprehensive definition of valvular AF, a total of 49 centres (94.2%) encountered a mechanical prosthetic heart valve and significant rheumatic mitral stenosis, 35 centres (67.3%) also considered bioprosthetic valves, and 25 centres (48.1%) included any significant valvular heart disease, requiring surgical repair in the definition of valvular AF. Only three centres (5.8%) would define valvular AF as the presence of any (even mild) valvular abnormality. None of the centres would use non-vitamin K antagonist oral anticoagulants (NOACs) in AF patients with mechanical prosthetic valves, only 5 centres (9.8%) would use NOACs in patients with significant mitral stenosis, 17 centres (32.7%) would consider the use of NOACs in patients with bioprosthetic valves, and 21 centres (41.2%) would use NOACs in patients with a non-recent transcatheter valve replacement/implantation, while 13 centres (25.5%) would never consider the use of NOACs in AF patients with even mild native heart valve abnormality. Our survey showed marked heterogeneity in the definition of valvular AF and thromboprophylactic treatments, with the use of variable NOACs in patients with valvular heart disease other than prosthetic heart valves or significant mitral stenosis, indicating that this term may be misleading and should not be used.

  17. Visualization of the hinge flow in a 5:1 scaled model of the medtronic parallel bileaflet heart valve prosthesis

    Science.gov (United States)

    Healy, T. M.; Fontaine, A. A.; Ellis, J. T.; Walton, S. P.; Yoganathan, A. P.

    In this work, a flow visualization experiment was performed to elucidate features of the retrograde hinge flow through a 5:1 scaled model of the Medtronic Parallel bileaflet heart valve. It was hypothesized that this model would provide detailed flow information facilitating identification of flow structures associated with thrombus formation in this valve. The experimental protocol was designed to ensure fluid dynamic similarity between the model and prototype heart valves. Flow was visualized using dye injection. The detailed flow structures observed showed the hinge's inflow channel was the most suspect region for thrombus formation. Here a complex helical structure was observed.

  18. In situ heart valve tissue engineering using a bioresorbable elastomeric implant - From material design to 12 months follow-up in sheep

    OpenAIRE

    Kluin, Jolanda Jolanda; Talacua, Hanna; Smits, AIPM Anthal; Emmert, MY Maximilian; Brugmans, MCP Marieke; Fioretta, ES Emanuela; Dijkman, PE Petra; Söntjens, SHM Serge; Duijvelshoff, R Renee; Dekker, S Sylvia; Janssen - van den Broek, WJT Marloes; Lintas, Valentina; Vink, A Aryan; Hoerstrup, S Simon; Janssen, HM Henk

    2017-01-01

    The creation of a living heart valve is a much-wanted alternative for current valve prostheses that suffer from limited durability and thromboembolic complications. Current strategies to create such valves, however, require the use of cells for in vitro culture, or decellularized human- or animal-derived donor tissue for in situ engineering. Here, we propose and demonstrate proof-of-concept of in situ heart valve tissue engineering using a synthetic approach, in which a cell-free, slow degrad...

  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. Donkey pericardium as an alternative bioprosthetic heart valve material.

    Science.gov (United States)

    Chen, Shanliang; Xu, Li; Liu, Yuxi; Li, Quan; Wang, Dong; Wang, Xuemei; Liu, Tianqi

    2013-03-01

    This study comparatively evaluates the characteristics of glutaraldehyde-treated acellular bovine and donkey pericardium using histological and electronic microscopic observation techniques, shrinkage temperature, and mechanical properties, as well as determining calcium and phosphorus content at 4 and 8 weeks after the subcutaneous implantation of donkey and bovine pericardium in Wistar rats. Donkey pericardium was significantly thinner compared with bovine pericardium (1.622 ±  0.161 mm vs. 4.027 ± 0.401 mm, P donkey pericardium was similar to that of bovine pericardium (87.43 ± 0.55°C vs. 87.50 ± 0.36°C, P =  0.810). No differences between groups were observed for maximum load (donkey: 21.64 ± 7.02 KN/m vs. bovine: 15.05 ± 4.50 KN/m, P = 0.082) and tear strength (donkey: 11.54 ± 5.33 MPa vs. bovine: 10.69 ±  3.77 MPa, P = 0.757). Calcium content was significantly lower in donkey pericardium compared with bovine pericardium at 4 weeks (690.15 ± 191.27 µg/g vs. 1381.73 ± 62.52 µg/g, P = 0.001) and 8 weeks (205.24 ± 62.40 µg/g vs. 910.48 ± 398.29 µg/g, P = 0.037). This preliminary study has confirmed that glutaraldehyde-tanned donkey pericardium, demonstrating reduced calcification and increased tensile strength, may provide a suitable bioprosthetic valve substitute.

  1. Relationship between exercise-induced heart rate increase and the formation of microbubbles and high-intensity transient signals in mechanical heart valve implanted patients.

    Science.gov (United States)

    Sünbül, Ayşegül; Kırbaş, Ahmet; Tanrıkulu, Nursen; Sengül, Cihan; Dağdeviren, Bahadır; Işık, Omer

    2014-08-29

    The formation and collapse of vapor-filled bubbles near a mechanical heart valve is called cavitation. Microbubbles can be detected in vivo by doppler ultrasonography (USG) as HITS (high intensity transient signals) in cranial circulation. We investigated the relationship between exercise induced heart rate increase and HITS formation in cranial circulation. Thirty-nine mechanical heart valve implanted (8 aortic valve replacement (AVR) + mitral valve replacement (MVR), 9 AVR, 22 MVR) patients aged 18-80 years old were included in our study. Microbubbles were counted in the left ventricular cavity via transthoracic echocardiography at rest per cardiac cycle. Afterwards transcranial Doppler USG was performed and HITS were counted in each patient's middle cerebral artery at 5 min duration. Subsequently an exercise test according to the Bruce protocol was performed. After achieving maximal heart rate, microbubbles in the left ventricle and HITS were counted again. Microbubbles in the left ventricle and transcranial HITS increased after exercise significantly compared to resting values (15.79 ±10.91 microbubbles/beat vs. 26.51 ±18.00 microbubbles/beat, p exercise (r = 0.55, p increasing as the heart rate increased and more HITS were propelled to the cerebral circulation. As previously shown, HITS can alter cognitive functions. Therefore heart rate control is essential in mechanical heart valve patients to protect neurocognitive functions.

  2. Low-Dose Gamma Irradiation of Decellularized Heart Valves Results in Tissue Injury in Vitro and in Vivo

    Science.gov (United States)

    Helder, Meghana R. K.; Hennessy, Ryan S.; Spoon, Daniel B.; Tefft, Brandon J.; Witt, Tyra A.; Marler, Ronald J.; Pislaru, Sorin V.; Simari, Robert D.; Stulak, John M.; Lerman, Amir

    2017-01-01

    Background Decellularized heart valves are emerging as a potential alternative to current bioprostheses for valve replacement. While techniques of decellularization have been thoroughly examined, terminal sterilization techniques have not received the same scrutiny. Methods This study evaluated low dose gamma irradiation as a sterilization method for decellularized heart valves. Incubation of valves and transmission electron microscopy evaluation after different doses of gamma irradiation were used to determine the optimal dose of gamma irradiation. Quantitative evaluation of mechanical properties was done by tensile mechanical testing of isolated cusps. Sterilize decellularized heart valves were tested in a sheep model (n=3, 1 1,500 Gy and 2 3,000 Gy) of pulmonary valve replacement. Results Valves sterilized with gamma radiation between 1,000 Gy and 3,000 Gy were found to be optimal with in-vitro testing. However, with in-vivo showed deteriorating valve function within 2 months. On explant the valve with 1,500 Gy gamma irradiation showed signs of endocarditis with neutrophils on hematoxylin and eosin staining, positive gram stain resembling streptococcus infection. The 3,000 Gy valves had no evidence of infection, but the hematoxylin and eosin staining showed evidence of wound remodeling with macrophages and fibroblasts. Tensile strength testing showed decreased strength (0 Gy-2.53±0.98 MPa, 1,500 Gy-2.03±1.23 MPa, 3,000 Gy-1.26±0.90 MPa) with increasing levels of irradiation. Conclusions Low dose gamma irradiation does not maintain the mechanical integrity of valves and the balance between sterilization and damage may not be able to be achieved with gamma irradiation. Other methods of terminal sterilization must be pursued and evaluated. PMID:26453425

  3. Surgical outcomes in native valve infectious endocarditis: the experience of the Cardiovascular Surgery Department – Cluj-Napoca Heart Institute

    Science.gov (United States)

    MOLNAR, ADRIAN; MURESAN, IOAN; TRIFAN, CATALIN; POP, DANA; SACUI, DIANA

    2015-01-01

    Background and aims The introduction of Duke’s criteria and the improvement of imaging methods has lead to an earlier and a more accurate diagnosis of infectious endocarditis (IE). The options for the best therapeutic approach and the timing of surgery are still a matter of debate and require a close colaboration between the cardiologist, the infectionist and the cardiac surgeon. Methods We undertook a retrospective, descriptive study, spanning over a period of five years (from January 1st, 2007 to December 31st, 2012), on 100 patients who underwent surgery for native valve infectious endocarditis in our unit. Results The patients’ age varied between 13 and 77 years (with a mean of 54 years), of which 85 were males (85%). The main microorganisms responsible for IE were: Streptococcus Spp. (21 cases – 21%), Staphylococcus Spp. (15 cases – 15%), and Enterococcus Spp. (9 cases – 9%). The potential source of infection was identified in 26 patients (26%), with most cases being in the dental area (16 cases – 16%). The lesions caused by IE were situated in the left heart in 96 patients (96%), mostly on the aortic valve (50 cases – 50%). In most cases (82%) we found preexisting endocardial lesions which predisposed to the development of IE, most of them being degenerative valvular lesions (38 cases – 38%). We performed the following surgical procedures: surgery on a single valve - aortic valve replacement (40 cases), mitral valve replacement (19 cases), mitral valve repair (1 case), surgery on more than one valve – mitral and aortic valve replacement (20 cases), aortic and tricuspid valve replacement (1 case), aortic valve replacement with a mechanical valve associated with mitral valve repair (5 cases), aortic valve replacement with a biological valve associated with mitral valve repair (2 cases), and mitral valve replacement with a mechanical valve combined with De Vega procedure on the tricuspid valve (1 case). In 5 patients (5%) the bacteriological

  4. Durability of bioprostheses for the tricuspid valve in patients with congenital heart disease.

    Science.gov (United States)

    Burri, Melchior; Vogt, Manfred O; Hörer, Jürgen; Cleuziou, Julie; Kasnar-Samprec, Jelena; Kühn, Andreas; Lange, Rüdiger; Schreiber, Christian

    2016-11-01

    Only little data exist on the durability of bioprostheses in the tricuspid position in patients with congenital heart disease (CHD). The aim of the study was to determine the reoperation rate and the valve function after primary implantation. Between 1990 and 2013, 51 patients with CHD underwent tricuspid valve (TV) replacement with a bioprosthesis. The median age at operation was 32 years (range: 8-69). The underlying morphology was Ebstein's anomaly in 62% of the patients. Implanted valves included 38 pericardial and 13 porcine valves. All available echocardiographic examinations (n = 714) and clinical data were retrospectively reviewed. Dysfunction was defined as an at least moderate regurgitation or a mean diastolic gradient ≥9 mmHg. Freedom from death, reoperation and prosthetic valve dysfunction was estimated using the Kaplan-Meier method. The 30-day mortality rate was 9%. The estimated survival rate was 86% at one and 80% at ten years. The freedom from reoperation at 1, 5 and 10 years was 100, 86 and 81%, and that from prosthesis dysfunction detected by echocardiography at 1, 5 and 10 years was 89, 66 and 58%, respectively. The main reason for dysfunction was insufficiency (89%). Valve implantation at an age below 16 years was associated with earlier reoperation and dysfunction (the 5-year freedom rate from reoperation/dysfunction was 70%/30% compared with 89%/78% in the rest of the patients, P = 0.016/0.0009). Serial echocardiography shows a high rate of dysfunction of TV bioprosthesis in patients with CHD, which already occurred a few years after implantation. In patients below 16 years of age, most prostheses are dysfunctional within 5 years. © The Author 2016. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  5. Numerical simulation of steady turbulent flow through trileaflet aortic heart valves--II. Results on five models.

    Science.gov (United States)

    Stevenson, D M; Yoganathan, A P; Williams, F P

    1985-01-01

    Turbulent flow simulations are run for five aortic trileaflet valve geometries, ranging from a valve leaflet orifice area of 1.1 cm2 (Model A1--very stenotic) to 5.0 cm2 (Model A5--natural valve). The simulated data compares well with experimental measurements made downstream of various aortic trileaflet valves by Woo (PhD Thesis, 1984). The location and approximate width and length of recirculation regions are correctly predicted. The less stenotic valve models reattach at the end of the aortic sinus region, 1.1 diameters downstream of the valve. The central jet exiting the less stenotic valve models is not significantly different from fully developed flow, and therefore recovers very quickly downstream of the reattachment point. The more stenotic valves disturb the flow to a greater degree, generating recirculation regions large enough to escape the sinuses and reattach further downstream. Peak turbulent shear stress values downstream of the aortic valve models which approximated prosthetic valves are 125 and 300 Nm-2, very near experimental observations of 150 to 350 Nm-2. The predicted Reynolds stress profiles also present the correct shape, a double peak profile, with the location of the peak occurring at the location of maximum velocity gradient, which occurs near the recirculation region. The pressure drop across model A2 (leaflet orifice area 1.6 cm2) is 20 mmHg at 1.6 diameters downstream. This compares well with values ranging from 19.5 to 26.2 mmHg for valves of similar orifice areas. The pressure drop decreases with decreasing valve stenosis, to a negligible value across the least stenotic valve model. Based on the good agreement between experimental measurements of velocity, shear stress and pressure drop, compared to the simulated data, the model has the potential to be a valuable tool in the analysis of heart valve designs.

  6. 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.

  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. Successful matrix guided tissue regeneration of decellularized pulmonary heart valve allografts in elderly sheep.

    Science.gov (United States)

    Theodoridis, Karolina; Tudorache, Igor; Calistru, Alexandru; Cebotari, Serghei; Meyer, Tanja; Sarikouch, Samir; Bara, Christoph; Brehm, Ralph; Haverich, Axel; Hilfiker, Andres

    2015-06-01

    In vivo repopulation of decellularized allografts with recipient cells leads to a positive remodeling of the graft matrix in juvenile sheep. In light of the increasing number of heart valve replacements among older patients (>65 years), this study focused on the potential for matrix-guided tissue regeneration in elderly sheep. Pulmonary valve replacement was performed in seven-year old sheep using decellularized (DV), decellularized and CCN1-coated (RV), or decellularized and in vitro reendothelialized pulmonary allografts (REV) (n=6, each group). CCN1 coating was applied to support re-endothelialization. In vitro re-endothelialization was conducted with endothelial-like cells derived from peripheral blood. Echocardiograms of all grafts showed adequate graft function after implantation and at explantation 3 or 6 months later. All explants were macroscopically free of thrombi at explantation, and revealed repopulation of the allografts on the adventitial side of valvular walls and proximal in the cusps. Engrafted cells expressed vimentin, sm α-actin, and myosin heavy chain 2, while luminal cell lining was positive for vWF and eNOS. Cellular repopulation of valvular matrix demonstrates the capacity for matrix-guided regeneration even in elderly sheep but is not improved by in vitro endothelialization, confirming the suitability of decellularized matrix for heart valve replacement in older individuals.

  9. 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.

  10. 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.

  11. A Nurse Practitioner Clinic: A Novel Approach to Supporting Patients Following Heart Valve Surgery.

    Science.gov (United States)

    McLachlan, Andrew; Sutton, Tim; Ding, Patricia; Kerr, Andrew

    2015-11-01

    Valvular heart disease is an important healthcare issue and its impacts are increasing. Following valve surgery, traditional models of care involve medical personnel, however, significant gaps in guideline adherence and delays in follow-up have been reported. Internationally, there is increasing evidence that specialist nurses can function in a variety of clinical settings and improve patient management. In 2009, a nurse practitioner clinic to support patients following valve surgery was established. We used a retrospective clinical audit and clinical review with descriptive statistics to describe the development of the clinic and to provide guidance for other services for model of care development. Over four years, 462 patients have been reviewed at least once, with over half having multiple assessments, 37% had rheumatic heart disease. These patients were 20 years younger and more likely to be women, non-European, current smokers and have atrial fibrillation. All patients received a focussed lifestyle, rheumatic, thromboembolic and endocarditis risk and symptom review with tailored support, advice and referral where appropriate. Four percent were referred back to a cardiologist for early evidence of valve dysfunction and a further 1.5% required urgent admission for unstable symptoms. The nurse practitioner clinic offers a systematic approach to promoting guideline adherence post valvular surgery. Important clinical symptoms and differences in health needs were identified and were actioned appropriately. Copyright © 2015 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

  12. 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.

  13. Management of abnormal uterine bleeding in women with mechanical heart valve prosthesis and anticoagulant therapy.

    Science.gov (United States)

    Saha, Pradip Kumar; Rakshit, Bibek Mohan; Jana, Narayan; Dutta, Sanjib; Roy, Subesha Basu; Sengupta, Gautam

    2011-12-01

    In a prospective observational case series, we assessed the effects and management and outcome of oral anticoagulant associated abnormal uterine bleeding in women with mechanical heart valve prosthesis. Six women with mechanical heart valve prosthesis, who were admitted with persistent severe vaginal bleeding between 2003 and 2010, were evaluated. For each woman, detailed history, treatment received, if there was any complication and their final outcome and satisfaction were recorded. All the 6 women were parous, with their ages ranging from 27 to 50 years. They were receiving oral anticoagulant therapy for mechanical heart valve prosthesis. Of the 6 women, 4 had uterine fibroids, and the other 2 had dysfunctional uterine bleeding.Three patients with uterine fibroids underwent abdominal hysterectomy, and one underwent balloon thermal ablation of endometrium. While 1 patient with dysfunctional uterine bleeding underwent hysterectomy, the other patient desirous for further children, required levonorgestrel intra-uterine system. Two women requiring hysterectomy, developed postoperative complications, one a massive intraperitoneal haemorrhage and another a rectus sheath haematoma. At follow-up, 5 women were satisfied, and 1 woman had died suddenly at home 1 year after hysterectomy. Because of the twin problem of heart disease and anticoagulant therapy, treatment of abnormal vaginal bleeding in these women is extremely challenging. Although medical treatment yields only temporary relief, endometrial ablative procedures or levonorgestrel intra-uterine system provides more durable solution. As anticoagulant associated peri-operative haemorrhage can be potentially fatal, hysterectomy should be reserved for women with major pelvic pathologies. Proper counselling and integrated management involving gynaecologist, cardiologist, haematologist and anaesthesiologist is essential to tackle this problem.

  14. 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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Cost-utility analysis of cardiac rehabilitation after conventional heart valve surgery versus usual care

    DEFF Research Database (Denmark)

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

    2017-01-01

    and monthly psycho-educational consultations or to usual care. Costs were measured from a societal perspective and quality-adjusted life years were based on the EuroQol five-dimensional questionnaire (EQ-5D). Estimates were presented as means and 95% confidence intervals (CIs) based on bootstrapping. Costs...... and effect differences were presented in a cost-effectiveness plane and were transformed into net benefit and presented in cost-effectiveness acceptability curves. Results No statistically significant differences were found in total societal costs (-1609 Euros; 95% CI: -6162 to 2942 Euros) or in quality......Background While cardiac rehabilitation in patients with ischaemic heart disease and heart failure is considered cost-effective, this evidence may not be transferable to heart valve surgery patients. The aim of this study was to investigate the cost-effectiveness of cardiac rehabilitation following...

  16. A correlation between long-term in vitro dynamic calcification and abnormal flow patterns past bioprosthetic heart valves.

    Science.gov (United States)

    Barannyk, Oleksandr; Fraser, Robert; Oshkai, Peter

    2017-06-01

    In this paper, a long-term in vitro dynamic calcification of three porcine aortic heart valves was investigated using a combined approach that involved accelerated wear testing of the valves in the rapid calcification solution, hydrodynamic assessment of the progressive change of effective orifice area (EOA) along with the transaortic pressure gradient, and quantitative visualization of the flow. The motivation for this study was developing a standardized, economical, and feasible in vitro testing methodology for bioprosthetic heart valve calcification, which would address both the hydrodynamic performance of the valves as well as the subsequent changes in the flow field. The results revealed the failure of the test valves at 40 million cycles mark, associated with the critical decrease in the EOA, followed by the increase in the maximum value of viscous shear stress of up to 52%, compared to the values measured at the beginning of the study. The decrease in the EOA was subsequently followed by the rapid increase in the maximum streamwise velocity of the central orifice jet up to the value of about 2.8 m/s, compared to the initial value of 2 m/s, and to the value of 2.2 m/s in the case of a control valve along with progressive narrowing of the velocity profile for two test valves. The significance of the current work is in demonstrating a correlation between calcification of the aortic valve and spatial as well as the temporal development of abnormal flow features.

  17. 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

  18. Learning discriminative distance functions for valve retrieval and improved decision support in valvular heart disease

    Science.gov (United States)

    Voigt, Ingmar; Vitanovski, Dime; Ionasec, Razvan I.; Tsymal, Alexey; Georgescu, Bogdan; Zhou, Shaohua K.; Huber, Martin; Navab, Nassir; Hornegger, Joachim; Comaniciu, Dorin

    2010-03-01

    Disorders of the heart valves constitute a considerable health problem and often require surgical intervention. Recently various approaches were published seeking to overcome the shortcomings of current clinical practice,that still relies on manually performed measurements for performance assessment. Clinical decisions are still based on generic information from clinical guidelines and publications and personal experience of clinicians. We present a framework for retrieval and decision support using learning based discriminative distance functions and visualization of patient similarity with relative neighborhood graphsbased on shape and derived features. We considered two learning based techniques, namely learning from equivalence constraints and the intrinsic Random Forest distance. The generic approach enables for learning arbitrary user-defined concepts of similarity depending on the application. This is demonstrated with the proposed applications, including automated diagnosis and interventional suitability classification, where classification rates of up to 88.9% and 85.9% could be observed on a set of valve models from 288 and 102 patients respectively.

  19. Mitral valve replacement in children and adolescents with rheumatic heart disease.

    Science.gov (United States)

    Stanley, J; Munsi, S; Sukumar, I P; Cherian, G

    1976-09-01

    To our knowledge, no documented hemodynamic studies in larger series of young patients undergoing valve replacement for rheumatic valvular disease have been reported previously. It seems to us that the natural history of rheumatic heart disease in India often follows a rapid and fulminant course which makes an aggressive surgical approach mandatory. An operative mortality of 22 % was seen in this series. Pronounced cardiac disability together with the poor general condition and the low nutritional status contributed in no small measure to this figure. Patients have been followed for periods ranging from 6 months to 6 years following corrective surgery. A remarkable absence of thrombo-embolic phenomena was a striking feature in the follow-up. There has been no evidence of rheumatic reactivation in any of these patients. This communication reinforces the beneficial results of valve replacement even at this young age when severe mitral incompetence exists refractory to medical treatment.

  20. [Prognostication of the outcome of heart valve prosthesis implantation by the method of nonlinear chaos dynamics of the heart rate].

    Science.gov (United States)

    Medvedev, A P; Gavrilushkin, A P; Kiselev, S V; Shelepnev, A V; Smirnov, N A

    2001-01-01

    An examination of 39 patients with heart diseases was performed before and after operations by the method of geometrical analysis of the nonlinear chaos (fractal) variability of the cardiac rhythm on the basis of the apparatus-programmed complex "Poly-spectrum". Five-minute-long registrations of ECG were carried on. On the basis of the data of examination of 195 healthy volunteers the reference norm of this method parameters was determined. Reliably lower parameters were found in patients with the acquired valvular disease. A dynamic investigation of the geometrical nonlinear structure of the cardiac rhythm has shown the possibility to make a prognosis of early complications after prosthetics of the heart valves.

  1. 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.

  2. A squeeze flow phenomenon at the closing of a bileaflet mechanical heart valve prosthesis.

    Science.gov (United States)

    Bluestein, D; Einav, S; Hwang, N H

    1994-11-01

    In vivo cavitation in cardiovascular flow fields may occur under very unusual circumstances as a localized transient phenomenon which are confined to very small regions in the vicinity of the valve body or leaflet surface. The violent collapse of cavitation bubbles induces local erosion that may lead to structural damage. The fluid mechanical factors that may cause in vivo cavitation inception in mechanical heart valve (MHV) prostheses are investigated. It is established that the closing velocity of the leaflet holds the key to MHV cavitation. During the final phase of valve closing, the fluid mass in the gap space between the closing occluder and the valve's body is squeezed into motion by the rapidly approaching boundaries. The flow pattern created by this motion (termed 'squeeze flow'), is found to be related to the valve geometry, and the impact velocity of the closing leaflet. Given the closing velocity of the leaflet and the geometry of the MHV, computational flow dynamics (CFD) are made to determine the velocity distributions in the gap flow field of a bileaflet MHV in the mitral position. A two dimensional, time dependent model of the gap space show that flow velocity in the gap space can reach values as high as 30 ms-1 in regions near the edge of the inflow surface of the Edwards Duromedics (ED) MHV leaflet. This high speed stream ejected from the gap channel can create the conditions that characterize cavitation. The location of the isolated high speed region corresponds to the surface erosion that was observed in a number of damaged ED-MHV explants.

  3. DSP implementation of a heart valve disorder detection system from a phonocardiogram signal.

    Science.gov (United States)

    Ari, S; Sensharma, K; Saha, G

    2008-01-01

    Auscultation, the technique of listening to heart sounds, remains a primary detection tool for diagnosing heart valve disorders. Other techniques, e.g. electrocardiography, ultrasound, etc, are accurate as well as informative; but expensive. With major advancement in the speed of computers, heart sound signals can be processed with ease by memory efficient digital signal processing and pattern recognition algorithms. This paper presents a digital signal processor (DSP) implementation of such a technique by using new threshold criteria. The proposed work can detect whether a heart sound recording belongs to a person suffering from valvular heart disease or not by giving 'diseased' or 'not diseased' decisions. The algorithm is tested for nine commonly occurring pathological problems and normal heart sound. The robustness of the algorithm is also checked against synthetically injected additive white Gaussian noise (AWGN) with different SNR levels. It is found to give an accuracy of 96.67% up to SNR values of 15 dB and 93.33% up to SNR values of 5 dB.

  4. Tri-leaflet valve design with a purge flow for heart-assist devices: an in vitro optimization study.

    Science.gov (United States)

    Timmel, Tobias; Seshadri, Santhosh; Goubergrits, Leonid; Affeld, Klaus; Kertzscher, Ulrich

    2012-01-01

    The objective of this study is to assess the effect of a purge flow on valves of pulsatile heart-assist devices. Clinical applications of these devices are still limited because of frequent thromboembolic complications. These complications often originate at the valves and the unavoidable flow separation regions that are found behind the leaflets. The flow separations cause a long residence time of blood that is considered particularly detrimental. To solve this problem, a valve with a purge flow is proposed. A purge flow is a jet, which is separated from the main blood flow and directed behind the leaflets into the sinus to flush it. Even though the purge flow does not prevent a flow separation, it shortens the residence time of the blood in the sinus. Thus, the purge flow improves the periodic washout of the blood in the region of flow separation. The complex purge flow was investigated in a tri-leaflet valve. The geometrical parameters of the valve were varied systematically. A statistical technique--the Taguchi method--was used to reduce the number of investigated models to 12. The flows through the resulting valve models were numerically simulated and analyzed. The evaluated models with the best results were subsequently investigated experimentally using different methods: hemodynamic tests in a valve tester and flow visualization using the dye washout method. It was shown that the purge flow can effectively wash out the sinus. Therefore, the purge flow valve reduces the potential of a thrombus formation normally associated with the valve.

  5. 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.)

  6. Aortic 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 Aortic Valve Disease Overview The human heart has ...

  7. The Fluid Mechanics of Transcatheter Heart Valve Leaflet Thrombosis in the Neo-Sinus.

    Science.gov (United States)

    Midha, Prem A; Raghav, Vrishank; Sharma, Rahul; Condado, Jose F; Okafor, Ikechukwu U; Rami, Tanya; Kumar, Gautam; Thourani, Vinod H; Jilaihawi, Hasan; Babaliaros, Vasilis; Makkar, Raj R; Yoganathan, Ajit P

    2017-07-19

    Background -Transcatheter heart valve (THV) thrombosis has been increasingly reported. In these studies, thrombus quantification has been based on 2D assessment of a 3D phenomenon. Methods -Post-procedural four-dimensional, volume-rendered CT (4DCT) data of CoreValve, Evolut R, and SAPIEN 3 transcatheter aortic valve replacement (TAVR) patients enrolled in the RESOLVE trial were included in this analysis. Patients on anticoagulation were excluded. SAPIEN 3 and CoreValve/Evolut R patients with and without hypo-attenuated leaflet thickening (HALT) were included in order to study differences between groups. Patients were classified as having THV thrombosis if there was any evidence of HALT. Anatomical and THV deployment geometries were analyzed, and thrombus volumes were computed through manual 3D reconstruction. We aimed to identify and evaluate risk factors that contribute to THV thrombosis through the combination of retrospective clinical data analysis and in vitro imaging in the space between the native and THV leaflets (neo-sinus). Results -SAPIEN 3 valves with leaflet thrombosis were on average 10% further expanded (by diameter) than those without (95.5 ± 5.2% vs. 85.4 ± 3.9%; p<0.001). However, this relationship was not evident with the CoreValve/Evolut R. In CoreValve/Evolut Rs with thrombosis, the thrombus volume increased linearly with implant depth (R(2) = 0.7; p < 0.001). This was not seen in the SAPIEN 3. The in vitro analysis showed that a supra-annular THV deployment resulted in a nearly 7-fold decrease in stagnation zone size (velocities less than 0.1 m/s) when compared to an intra-annular deployment. In addition, the in vitro model indicated that the size of the stagnation zone increased as cardiac output decreased. Conclusions -While TAVR thrombosis is a multi-factorial process involving foreign materials, patient-specific blood chemistry and complex flow patterns, our study indicates that deployed THV geometry may have implications on the

  8. Degradable Chitosan-Collagen Composites Seeded with Cells as Tissue Engineered Heart Valves.

    Science.gov (United States)

    Fu, Jian-Hua; Zhao, Man; Lin, Yan-Rong; Tian, Xu-Dong; Wang, Ya-Dong; Wang, Zhen-Xing; Wang, Le-Xin

    2017-01-01

    Degradable collagen-chitosan composite materials have been used to fabricate tissue engineered heart valves. The aims of this study were to demonstrate that the collagen-chitosan composite scaffolds are cytocompatible, and endothelial cells can be differentiated from bone marrow mesenchymal stem cells (BMSCs) when seeded onto the scaffolds. The adhesion and biological activities of the seeded cells were also investigated. Collagen-chitosan composite material was used as the cell matrix, and smooth muscle cells, fibroblasts and BMSCs were used as seed cells. After four weeks of in vitro culture, the smooth muscle cells, fibroblasts, and BMSCs were sequentially seeded into the collagen-chitosan composite material. After four weeks in culture, the cellular density and activity were assessed on segments of the tissue engineered heart valve scaffolds to determine the cell viability and proliferation in the collagen-chitosan composite material. The tissue engineered heart valves stained positively for both smooth muscle actin and endothelial cell factor VIII, suggesting that the seeded cells were in fact smooth muscle cells, fibroblasts, and endothelial cells. The 6-ketone prostaglandin content, as measured by radioimmunoassay, of the collagen-chitosan cell culture fluid was higher than that of the serum-free medium (P chitosan composite scaffolds. The seeded cells retained their biological activity after being cultured in vitro and seeded into the collagen-chitosan composite material. Copyright © 2016 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

  9. Experience with enoxaparin in patients with mechanical heart valves who must withhold acenocumarol

    Science.gov (United States)

    Ferreira, I; Dos, L; Tornos, P; Nicolau, I; Permanyer-Miralda, G; Soler-Soler, J

    2003-01-01

    Objectives: To evaluate the incidence of thromboembolic and haemorrhagic events in a cohort of patients with mechanical heart valves who had to withhold acenocumarol and were treated with enoxaparin. Design: Observational prospective study. Setting: In hospital; after discharge, and follow up by telephone call. Patients and methods: All consecutive patients with mechanical heart valves admitted to the authors’ hospital between May 1999 and January 2002 who had to interrupt treatment with acenocumarol and were treated with enoxaparin as an alternative to other methods were enrolled. In each patient, the following characteristics were prospectively determined: the reason for interrupting acenocumarol, demographic data, estimated global risk for thromboembolic events, international normalised ratio before starting enoxaparin treatment, number of days taking enoxaparin, and mean level of anti-Xa activity during treatment. All patients were followed up through clinical history during the hospitalisation and by telephone after discharge to detect thromboembolic events. Main outcome measure: Presence of thromboembolic or haemorrhagic events. Results: 82 patients were identified and followed up for a mean of 2.8 months (range 1.5–3.5 months) after discharge. 61 of them (74%) had one or more associated thromboembolic risk factors. Acenocumarol was interrupted (to perform an invasive procedure in 74 patients and because of haemorrhagic complication in 8) an average of 11.2 days (range 3–40 days). Most patients received the standard enoxaparin dose (1 mg/kg at 12 hour intervals). Mean (SD) anti-Xa activity was 0.58 (0.3) IU/ml (median 0.51). There were 8 minor and 1 major bleeding events during enoxaparin treatment. No thromboembolic complications were clinically detected during hospitalisation or during follow up (95% confidence interval 0% to 3.6%). Conclusions: Enoxaparin may be an effective and relatively safe substitute anticoagulant for patients with mechanical

  10. Viscoelastic behaviour of human blood and polyacrylamide model fluids for heart valve testing

    Science.gov (United States)

    Lerche, Dietmar; Vlastos, Georgios; Koch, Brigitte; Pohl, Manfred; Affeld, Klaus

    1993-06-01

    New heart valves and other cardiovascular assist systems have to be tested for hydrodynamic performance. In place of human blood simple model fluids like glycerol solutions are employed often due to ethical and practical reasons. But blood exhibits complex non-Newtonian and viscoelastic behaviour. Rheological blood properties are reviewed based on literature and own experimental results. Furthermore we studied polymer solutions with respect to blood-like flow behaviour. Rheology was assessed by means of the low shear rotational viscometer (LS 40, Mettler-Toledo, Switzerland) under stationary and dynamic shear conditions (variation of frequency and angular displacement).

  11. Exercise-based cardiac rehabilitation for adults after Heart valve surgery (protocol)

    DEFF Research Database (Denmark)

    Lærum Sibilitz, Kristine; Berg, Selina Kikkenborg; Tang, Lars Hermann

    2013-01-01

    This is the protocol for a review and there is no abstract. The objectives are as follows: To assess the benefits and harms of exercise-based intervention programmes (exercise-based interventions alone or in combination with psycho-educational components), compared to no intervention, or treatment...... as usual, in adults who have had heart valve surgery. In this review we will focus on programmes that include an exercise-based intervention with, or without, another rehabilitation component (such as a psycho-educational component)....

  12. An immersogeometric variational framework for fluid-structure interaction: application to bioprosthetic heart valves.

    Science.gov (United States)

    Kamensky, David; Hsu, Ming-Chen; Schillinger, Dominik; Evans, John A; Aggarwal, Ankush; Bazilevs, Yuri; Sacks, Michael S; Hughes, Thomas J R

    2015-02-01

    In this paper, we develop a geometrically flexible technique for computational fluid-structure interaction (FSI). The motivating application is the simulation of tri-leaflet bioprosthetic heart valve function over the complete cardiac cycle. Due to the complex motion of the heart valve leaflets, the fluid domain undergoes large deformations, including changes of topology. The proposed method directly analyzes a spline-based surface representation of the structure by immersing it into a non-boundary-fitted discretization of the surrounding fluid domain. This places our method within an emerging class of computational techniques that aim to capture geometry on non-boundary-fitted analysis meshes. We introduce the term "immersogeometric analysis" to identify this paradigm. The framework starts with an augmented Lagrangian formulation for FSI that enforces kinematic constraints with a combination of Lagrange multipliers and penalty forces. For immersed volumetric objects, we formally eliminate the multiplier field by substituting a fluid-structure interface traction, arriving at Nitsche's method for enforcing Dirichlet boundary conditions on object surfaces. For immersed thin shell structures modeled geometrically as surfaces, the tractions from opposite sides cancel due to the continuity of the background fluid solution space, leaving a penalty method. Application to a bioprosthetic heart valve, where there is a large pressure jump across the leaflets, reveals shortcomings of the penalty approach. To counteract steep pressure gradients through the structure without the conditioning problems that accompany strong penalty forces, we resurrect the Lagrange multiplier field. Further, since the fluid discretization is not tailored to the structure geometry, there is a significant error in the approximation of pressure discontinuities across the shell. This error becomes especially troublesome in residual-based stabilized methods for incompressible flow, leading to

  13. An immersogeometric variational framework for fluid–structure interaction: application to bioprosthetic heart valves

    Science.gov (United States)

    Kamensky, David; Hsu, Ming-Chen; Schillinger, Dominik; Evans, John A.; Aggarwal, Ankush; Bazilevs, Yuri; Sacks, Michael S.; Hughes, Thomas J. R.

    2014-01-01

    In this paper, we develop a geometrically flexible technique for computational fluid–structure interaction (FSI). The motivating application is the simulation of tri-leaflet bioprosthetic heart valve function over the complete cardiac cycle. Due to the complex motion of the heart valve leaflets, the fluid domain undergoes large deformations, including changes of topology. The proposed method directly analyzes a spline-based surface representation of the structure by immersing it into a non-boundary-fitted discretization of the surrounding fluid domain. This places our method within an emerging class of computational techniques that aim to capture geometry on non-boundary-fitted analysis meshes. We introduce the term “immersogeometric analysis” to identify this paradigm. The framework starts with an augmented Lagrangian formulation for FSI that enforces kinematic constraints with a combination of Lagrange multipliers and penalty forces. For immersed volumetric objects, we formally eliminate the multiplier field by substituting a fluid–structure interface traction, arriving at Nitsche’s method for enforcing Dirichlet boundary conditions on object surfaces. For immersed thin shell structures modeled geometrically as surfaces, the tractions from opposite sides cancel due to the continuity of the background fluid solution space, leaving a penalty method. Application to a bioprosthetic heart valve, where there is a large pressure jump across the leaflets, reveals shortcomings of the penalty approach. To counteract steep pressure gradients through the structure without the conditioning problems that accompany strong penalty forces, we resurrect the Lagrange multiplier field. Further, since the fluid discretization is not tailored to the structure geometry, there is a significant error in the approximation of pressure discontinuities across the shell. This error becomes especially troublesome in residual-based stabilized methods for incompressible flow, leading

  14. In situ heart valve tissue engineering using a bioresorbable elastomeric implant - From material design to 12 months follow-up in sheep

    NARCIS (Netherlands)

    Kluin, Jolanda; Talacua, Hanna; Smits, Anthal I P M; Emmert, Maximilian Y; Brugmans, Marieke C P; Fioretta, Emanuela S; Dijkman, Petra E; Söntjens, Serge H M; Duijvelshoff, Renée; Dekker, Sylvia; Janssen-van den Broek, Marloes W J T; Lintas, Valentina; Vink, Aryan; Hoerstrup, Simon P; Janssen, Henk M; Dankers, Patricia Y W; Baaijens, Frank P T; Bouten, Carlijn V C

    2017-01-01

    The creation of a living heart valve is a much-wanted alternative for current valve prostheses that suffer from limited durability and thromboembolic complications. Current strategies to create such valves, however, require the use of cells for in vitro culture, or decellularized human- or

  15. Aortic and mitral valve surgery on the beating heart is lowering cardiopulmonary bypass and aortic cross clamp time.

    Science.gov (United States)

    Gersak, Borut; Sutlic, Zeljko

    2002-01-01

    The concept of cardiac surgery on the beating heart is acceptable rationale for the cardiac surgery in the next millenium. Beating heart (off-pump) coronary artery bypass grafting (CABG) techniques have led us to consider the possibility for performing the aortic and mitral valve surgery (mitral valve repairs and replacements - with or without CABG) on the beating heart with the technique of retrograde oxygenated coronary sinus perfusion. We used the technique of retrograde oxygenated blood coronary sinus perfusion in 78 patients (Group All) - (36 patients were with extremely low ejection fraction (Group X) - 62% of whom were in New York Heart Association (NYHA) class 4 and 34% of whom were in NYHA class 3). The procedures for the patients were: aortic, mitral and tricuspid valve surgery, in combination with CABG in ischemic patients. CABG was done in all the cases off-pump. In addition, we performed a case match study for 37 patients with good ejection fraction (51.65 +/- 11.88) (Beating Heart Group) operated on the beating heart with most appropriate group of patients (No. 37) operated in our institutions on arrested heart (ejection fraction 51.07 +/- 12.93) (Arrested Heart Group). The case match selection criteria were: gender, left ventricular ejection fraction, atrial fibrillation, hypertension, pulmonary hypertension, and diabetes. The selected beating heart group and selected arrested heart groups were without statistically significant differences for the mentioned criteria. There were statistically significant differences between Beating Heart Group and Arrested Heart Group in the duration of Cardiopulmonary Bypass Time (69.35 +/- 13.52 min. versus 93.59 +/- 28.54 min.), pHeart Group were lower. There was no statistical difference in complication rate for both the groups for: sternal infection, bleeding, death, atrial fibrillation, AV block and neurological complications. The total early mortality for all the patients was 5.1% (4 out of 78) - for the group

  16. Transcatheter Heart Valve Selection and Permanent Pacemaker Implantation in Patients With Pre-Existent Right Bundle Branch Block.

    Science.gov (United States)

    van Gils, Lennart; Tchetche, Didier; Lhermusier, Thibault; Abawi, Masieh; Dumonteil, Nicolas; Rodriguez Olivares, Ramón; Molina-Martin de Nicolas, Javier; Stella, Pieter R; Carrié, Didier; De Jaegere, Peter P; Van Mieghem, Nicolas M

    2017-03-03

    Right bundle branch block is an established predictor for new conduction disturbances and need for a permanent pacemaker (PPM) after transcatheter aortic valve replacement. The aim of the study was to evaluate the absolute rates of transcatheter aortic valve replacement related PPM implantations in patients with pre-existent right bundle branch block and categorize for different transcatheter heart valves. We pooled data on 306 transcatheter aortic valve replacement patients from 4 high-volume centers in Europe and selected those with right bundle branch block at baseline without a previously implanted PPM. Logistic regression was used to evaluate whether PPM rate differed among transcatheter heart valves after adjustment for confounders. Mean age was 83±7 years and 63% were male. Median Society of Thoracic Surgeons score was 6.3 (interquartile range, 4.1-10.2). The following transcatheter valve designs were used: Medtronic CoreValve (n=130; Medtronic, Minneapolis, MN); Edwards Sapien XT (ES-XT; n=124) and Edwards Sapien 3 (ES-3; n=32; Edwards Lifesciences, Irvine, CA); and Boston Scientific Lotus (n=20; Boston Scientific Corporation, Marlborough, MA). Overall permanent pacemaker implantation rate post-transcatheter aortic valve replacement was 41%, and per valve design: 75% with Lotus, 46% with CoreValve, 32% with ES-XT, and 34% with ES-3. The indication for PPM implantation was total atrioventricular block in 98% of the cases. Lotus was associated with a higher PPM rate than all other valves. PPM rate did not differ between ES-XT and ES-3. Ventricular paced rhythm at 30-day and 1-year follow-up was present in 81% at 89%, respectively. Right bundle branch block at baseline is associated with a high incidence of PPM implantation for all transcatheter heart valves. PPM rate was highest for Lotus and lowest for ES-XT and ES-3. Pacemaker dependency remained high during follow-up. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by

  17. Evolving hybrid approaches: the preservation of the 'neglected' pulmonary valve function in patients with congenital heart disease.

    Science.gov (United States)

    Vida, Vladimiro L; Bacha, Emile; Stellin, Giovanni

    2016-07-01

    The involvement of the hemodynamic expertise in the operating room led to the development of new strategies aimed to improve both early and long-term outcome of patients with congenital heart disease. During the last decade, with the aim of preserving the pulmonary valve function, we embarked on a new surgical approach, which combines surgical and interventional techniques, which are performed in the operating room. We believe that the preservation of the pulmonary valve function can be extended to any patients with classic tetralogy of Fallot and other selected patients with congenital pulmonary valve hypoplasia and dysfunction.

  18. 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; dos Santos, Ândrea Kely Campos Ribeiro; Sobrinho, Carlos Roberto Martins Rodrigues; Mota, Mário Rogério Lima; Sousa, Fabrício Bitu; Alves, Ana Paula Negreiros Nunes

    2015-01-01

    Abstract 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

  19. ESC Working Group on Valvular Heart Disease position paper--heart valve clinics: organization, structure, and experiences.

    Science.gov (United States)

    Lancellotti, Patrizio; Rosenhek, Raphael; Pibarot, Philippe; Iung, Bernard; Otto, Catherine M; Tornos, Pilar; Donal, Erwan; Prendergast, Bernard; Magne, Julien; La Canna, Giovanni; Piérard, Luc A; Maurer, Gerald

    2013-06-01

    With an increasing prevalence of patients with valvular heart disease (VHD), a dedicated management approach is needed. The challenges encountered are manifold and include appropriate diagnosis and quantification of valve lesion, organization of adequate follow-up, and making the right management decisions, in particular with regard to the timing and choice of interventions. Data from the Euro Heart Survey have shown a substantial discrepancy between guidelines and clinical practice in the field of VHD and many patients are denied surgery despite having clear indications. The concept of heart valve clinics (HVCs) is increasingly recognized as the way to proceed. At the same time, very few centres have developed such expertise, indicating that specific recommendations for the initial development and subsequent operating requirements of an HVC are needed. The aim of this position paper is to provide insights into the rationale, organization, structure, and expertise needed to establish and operate an HVC. Although the main goal is to improve the clinical management of patients with VHD, the impact of HVCs on education is of particular importance: larger patient volumes foster the required expertise among more senior physicians but are also fundamental for training new cardiologists, medical students, and nurses. Additional benefits arise from research opportunities resulting from such an organized structure and the delivery of standardized care protocols. The growing volume of patients with VHD, their changing characteristics, and the growing technological opportunities of refined diagnosis and treatment in addition to the potential dismal prognosis if overlooked mandate specialized evaluation and care by dedicated physicians working in a specialized environment that is called the HVC.

  20. Effects of Leaflet Design on Transvalvular Gradients of Bioprosthetic Heart Valves.

    Science.gov (United States)

    Dabiri, Yaghoub; Ronsky, Janet; Ali, Imtiaz; Basha, Ameen; Bhanji, Alisha; Narine, Kishan

    2016-12-01

    Bioprosthetic aortic valves (BAVs) are becoming the prostheses of choice in heart valve replacement. The objective of this paper is to assess the effects of leaflet geometry on the mechanics and hemodynamics of BAVs in a fluid structure interaction model. The curvature and angle of leaflets were varied in 10 case studies whereby the following design parameters were altered: a circular arch, a line, and a parabola for the radial curvature, and a circular arch, a spline, and a parabola for the circumferential curvature. Six different leaflet angles (representative of the inclination of the leaflets toward the surrounding aortic wall) were analyzed. The 3-dimensional geometry of the models were created using SolidWorks, Pointwise was used for meshing, and Comsol Multiphysics was used for implicit finite element calculations. Realistic loading was enforced by considering the time-dependent strongly-coupled interaction between blood flow and leaflets. Higher mean pressure gradients as well as von Mises stresses were obtained with a parabolic or circular curvature for radial curvature or a parabolic or spline curvature for the circumferential curvature. A smaller leaflet angle was associated with a lower pressure gradient, and, a lower von Mises stress. The leaflet curvature and angle noticeably affected the speed of valve opening, and closing. When a parabola was used for circumferential or radial curvature, leaflets displacements were asymmetric, and they opened and closed more slowly. A circular circumferential leaflet curvature, a linear leaflet radial curvature, and leaflet inclination toward the surrounding aortic wall were associated with superior BAVs mechanics.

  1. Management of patients with prosthetic heart valves during non-cardiac surgery.

    Science.gov (United States)

    Prendergast, Bernard D

    2004-01-01

    Non-cardiac surgery in patients with prosthetic heart valves poses the particular hazards of infective endocarditis, increased bleeding risk and the possibility of acute/subacute valve thrombosis or systemic thromboembolism associated with interrupted anticoagulation. Management is complicated by the absence of randomised trials examining peri-operative anticoagulation management. Thromboembolic risk increases substantially when oral anticoagulation is discontinued and valve thrombosis may be inapparent for 1-2 months. This delayed diagnosis makes it difficult to identify the inciting event, either clinically or in experimental trials. Furthermore, the absence of early post-operative events may falsely suggest that peri-operative anticoagulation was safe and adequate. The approach to management therefore remains controversial. Seamless oral anticoagulation is preferred whenever possible and this is safe for a range of minor procedures, including cardiac catheterisation, dental and ophthalmic surgery. Major surgical procedures require withdrawal of oral anticoagulation before surgery to lower the international normalised ratio (INR) to anticoagulation with unfractionated heparin which should be started when the INR is patients and anticoagulation is then resumed post-operatively, though therapeutic levels are not achieved for several days. The determination of which patients require prolonged overlap of heparin and oral anticoagulants is difficult. Clinical judgement is required but these regimes are strongly recommended for those at highest risk of thromboembolism. With strict adherence to these guidelines, the incidence of major complications is low.

  2. 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

  3. Coronary anatomy in children with bicuspid aortic valves and associated congenital heart disease.

    Science.gov (United States)

    Koenraadt, Wilke M C; Bartelings, Margot M; Bökenkamp, Regina; Gittenberger-de Groot, Adriana C; DeRuiter, Marco C; Schalij, Martin J; Jongbloed, Monique Rm

    2017-07-27

    In patients with bicuspid aortic valve (BAV), coronary anatomy is variable. High take-off coronary arteries have been described, but data are scarce, especially when associated with complex congenital heart disease (CHD). The purpose of this study was to describe coronary patterns in these patients. In 84 postmortem heart specimens with BAV and associated CHD, position and height of the coronary ostia were studied and related to BAV morphology. High take-off right (RCA) and left coronary arteries (LCA) were observed in 23% and 37% of hearts, respectively, most frequently in hearts with hypoplastic left ventricle (HLV) and outflow tract anomalies. In HLV, high take-off was observed in 18/40 (45%) more frequently of LCA (n=14) than RCA (n=6). In hearts with aortic hypoplasia, 8/13 (62%) had high take-off LCA and 6/13 (46%) high take-off RCA. High take-off was seen 19 times in 22 specimens with perimembranous ventricular septal defect (RCA 8, LCA 11). High take-off was associated with type 1A BAV (raphe between right and left coronary leaflets), more outspoken for the RCA. Separate ostia of left anterior descending coronary artery and left circumflex coronary artery were seen in four hearts (5%), not related to specific BAV morphology. High take-off coronary arteries, especially the LCA, occur more frequently in BAV with associated CHD than reported in normal hearts and isolated BAV. Outflow tract defects and HLV are associated with type 1A BAV and high take-off coronary arteries. Although it is unclear whether these findings in infants with detrimental outcome can be related to surviving adults, clinical awareness of variations in coronary anatomy is warranted. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  4. [Takayasu arteritis associated with heart valve diseases (pulmonary and aortic) and arteritis (coronary and renal)].

    Science.gov (United States)

    Rangel-Abundis, A; Fraga, A; Badui, E; Guijosa, N; Navarro, J

    1992-01-01

    The most severe arteritis due to Takayasu's disease are those related to renal and coronary arteries. The first one because it produces severe arterial hypertension and the second one because it puts the patient in high risk of suffering either myocardial ischemia or infarction. These situations worsen when this entity is associated to valvular heart lesions. The authors present the clinical cases of two female patients with Takayasu's disease. One of them in acute phase of the illness, where coronary arteritis, mild coarctation of the aorta, right pulmonary artery stenosis, and pulmonary valve stenosis were present. The second patient was seen during the remission phase of the disease with obstruction of the left subclavicular artery, renal arteritis, severe arterial hypertension and aortic valve insufficiency. The authors discuss the prognosis of patients with Takayasu's disease associated to valvular heart disease and its role in the etiology of pulmonary valvular stenosis. Finally, the authors point out the importance of recognizing the active and non active phases of the Takayasu's disease in relation of the adequate stage for surgical treatment of the lesions caused by this disease.

  5. Significance of epicardial fat in the diagnosis of coronary atherosclerosis before heart valve surgery

    Directory of Open Access Journals (Sweden)

    Joanna de Zayas Galguera

    2016-01-01

    Full Text Available Introduction: Epicardial fat has been shown to be related not only with clinical atherosclerosis, but also with subclinical atherosclerosis.Objective: To determine the significance of epicardial fat in the diagnosis of coronary atherosclerosis in patients with valvular heart disease.Method: The study included 62 patients scheduled for valve replacement surgery who had previously undergone invasive coronary angiography. Before surgery, epicardial fat measurement was performed by echocardiogram. Sensitivity, specificity, and positive and negative predictive values were determined, as well as the validity index and likelihood ratios for positive and negative tests.Results: 88.7% of patients with heart valve disease had no lesions in the coronary arteries. The most relevant parameters obtained from the measurement of epicardial fat were 78% sensitivity and 93% negative predictive value, and a ratio of positive and negative likelihood of 2.23 and 0.34 respectively.Conclusions: The group of patients with significant coronary lesions showed higher levels of epicardial fat than the group without coronary lesions. It confirms the diagnostic validity of this test for the detection of coronary atherosclerosis in the study patients.

  6. Sox9 transcriptionally represses Spp1 to prevent matrix mineralization in maturing heart valves and chondrocytes.

    Directory of Open Access Journals (Sweden)

    Jacqueline D Peacock

    Full Text Available Sox9 is an SRY-related transcription factor required for expression of cartilaginous genes in the developing skeletal system and heart valve structures. In contrast to positively regulating cartilaginous matrix, Sox9 also negatively regulates matrix mineralization associated with bone formation. While the transcriptional activation of Sox9 target genes during chondrogenesis has been characterized, the mechanisms by which Sox9 represses osteogenic processes are not so clear. Using ChIP-on-chip and luciferase assays we show that Sox9 binds and represses transactivation of the osteogenic glycoprotein Spp1. In addition, Sox9 knockdown in post natal mouse heart valve explants and rib chondrocyte cultures promotes Spp1 expression and matrix mineralization, while attenuating expression of cartilage genes Type II Collagen and Cartilage Link Protein. Further, we show that Spp1 is required for matrix mineralization induced by Sox9 knockdown. These studies provide insights into the molecular mechanisms by which Sox9 prevents pathologic matrix mineralization in tissues that must remain cartilaginous.

  7. 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.

  8. Protein stability in stored decellularized heart valve scaffolds and diffusion kinetics of protective molecules.

    Science.gov (United States)

    Wang, Shangping; Oldenhof, Harriëtte; Dai, Xiaolei; Haverich, Axel; Hilfiker, Andres; Harder, Michael; Wolkers, Willem F

    2014-02-01

    Decellularized tissues can be used as matrix implants. The aims of this study were to investigate protein stability and solvent accessibility in decellularized pulmonary heart valve tissues. Protein denaturation profiles of tissues were studied by differential scanning calorimetry. Protein solvent accessibility of tissue exposed to D2O, and diffusion kinetics of various protective molecules were studied by Fourier transform infrared spectroscopy. Little changes were observed in the protein denaturation temperature during storage, at either 5 or 40°C. Glycerol was found to stabilize proteins; it increased the protein denaturation temperature. The stabilizing effect of glycerol disappeared after washing the sample with saline solution. Hydrogen-to-deuterium exchange rates of protein amide groups were fastest in leaflet tissue, followed by artery and muscle tissue. Diffusion of glycerol was found to be fastest in muscle tissue, followed by artery and leaflet tissue. Diffusion coefficients were derived and used to estimate the time needed to reach saturation. Fixation of tissue with glutaraldehyde had little effects on exchange and diffusion rates. Diffusion rates decreased with increasing molecular size. Proteins in decellularized heart valve tissue are stable during storage. Glycerol increases protein stability in a reversible manner. Solvent accessibility studies of protein amide groups provide an additional tool to study proteins in tissues. Diffusion coefficients can be derived to simulate diffusion kinetics of protective molecules in tissues. This study provides novel tools to evaluate protein stability and solvent accessibility in tissues, which can be used to develop biopreservation strategies.

  9. Profile of Heart Donors from the Human Valve Bank of the Santa Casa de Misericórdia de Curitiba.

    Science.gov (United States)

    Ferreira, Renata Maria; Costa, Marise Teresinha Brenner Affonso da; Canciglieri Junior, Osiris; Sant'Anna, Ângelo Márcio Oliveira

    2016-04-01

    Human heart valves are used as replacement valves and have satisfactory functional results compared with conventional prostheses. Characterize the profile of effective heart donors from the human valve bank of the santa casa de misericórdia de curitiba and analyze the association between the profile variables. It consists of a retrospective and quantitative study of electronic medical records from heart donors for heart valves. every heart donation made to the bank between january 2004 and december 2014 was studied. 2,149 donations were analyzed, from donors aged 0 to 71 years old, with an average of 34.9 ± 15.03 years old. most donors were male 65.7% (n=1,411) and 34.3% (n=738) were female. among the most frequent causes of the donors' death are trauma at 53% (n=1,139) and cerebral vascular accident at 34.2% (n=735). there was significant statistical association between the analyzed variables. There has been an improvement in brazil's donation rate, being essential that the tissue banks work together with the state and federal district centers for notification, procurement and distribution of organs in order to increase the number of donors.

  10. Simulation of Exercise-Induced Syncope in a Heart Model with Severe Aortic Valve Stenosis

    Directory of Open Access Journals (Sweden)

    Matjaž Sever

    2012-01-01

    Full Text Available Severe aortic valve stenosis (AVS can cause an exercise-induced reflex syncope (RS. The precise mechanism of this syncope is not known. The changes in hemodynamics are variable, including arrhythmias and myocardial ischemia, and one of the few consistent changes is a sudden fall in systemic and pulmonary arterial pressures (suggesting a reduced vascular resistance followed by a decline in heart rate. The contribution of the cardioinhibitory and vasodepressor components of the RS to hemodynamics was evaluated by a computer model. This lumped-parameter computer simulation was based on equivalent electronic circuits (EECs that reflect the hemodynamic conditions of a heart with severe AVS and a concomitantly decreased contractility as a long-term detrimental consequence of compensatory left ventricular hypertrophy. In addition, the EECs model simulated the resetting of the sympathetic nervous tone in the heart and systemic circuit during exercise and exercise-induced syncope, the fluctuating intra-thoracic pressure during respiration, and the passive relaxation of ventricle during diastole. The results of this simulation were consistent with the published case reports of exertional syncope in patients with AVS. The value of the EEC model is its ability to quantify the effect of a selective and gradable change in heart rate, ventricular contractility, or systemic vascular resistance on the hemodynamics during an exertional syncope in patients with severe AVS.

  11. Simulation of exercise-induced syncope in a heart model with severe aortic valve stenosis.

    Science.gov (United States)

    Sever, Matjaž; Ribarič, Samo; Kordaš, Marjan

    2012-01-01

    Severe aortic valve stenosis (AVS) can cause an exercise-induced reflex syncope (RS). The precise mechanism of this syncope is not known. The changes in hemodynamics are variable, including arrhythmias and myocardial ischemia, and one of the few consistent changes is a sudden fall in systemic and pulmonary arterial pressures (suggesting a reduced vascular resistance) followed by a decline in heart rate. The contribution of the cardioinhibitory and vasodepressor components of the RS to hemodynamics was evaluated by a computer model. This lumped-parameter computer simulation was based on equivalent electronic circuits (EECs) that reflect the hemodynamic conditions of a heart with severe AVS and a concomitantly decreased contractility as a long-term detrimental consequence of compensatory left ventricular hypertrophy. In addition, the EECs model simulated the resetting of the sympathetic nervous tone in the heart and systemic circuit during exercise and exercise-induced syncope, the fluctuating intra-thoracic pressure during respiration, and the passive relaxation of ventricle during diastole. The results of this simulation were consistent with the published case reports of exertional syncope in patients with AVS. The value of the EEC model is its ability to quantify the effect of a selective and gradable change in heart rate, ventricular contractility, or systemic vascular resistance on the hemodynamics during an exertional syncope in patients with severe AVS.

  12. Cardiac rehabilitation increases physical capacity but not mental health after heart valve surgery: a randomised clinical trial.

    Science.gov (United States)

    Sibilitz, Kirstine L; Berg, Selina K; Rasmussen, Trine B; Risom, Signe Stelling; Thygesen, Lau C; Tang, Lars; Hansen, Tina B; Johansen, Pernille Palm; Gluud, Christian; Lindschou, Jane; Schmid, Jean Paul; Hassager, Christian; Køber, Lars; Taylor, Rod S; Zwisler, Ann-Dorthe

    2016-12-15

    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 valve surgery. The trial was an investigator-initiated, randomised superiority trial (The CopenHeartVR trial, VR; valve replacement or repair). We randomised 147 patients after heart valve surgery 1:1 to 12 weeks of cardiac rehabilitation consisting of physical exercise and monthly psycho-educational consultations (intervention) versus usual care without structured physical exercise or psycho-educational consultations (control). Primary outcome was physical capacity measured by VO2 peak and secondary outcome was self-reported mental health measured by Short Form-36. 76% were men, mean age 62 years, with aortic (62%), mitral (36%) or tricuspid/pulmonary valve surgery (2%). Cardiac rehabilitation compared with control had a beneficial effect on VO2 peak at 4 months (24.8 mL/kg/min vs 22.5 mL/kg/min, p=0.045) but did not affect Short Form-36 Mental Component Scale at 6 months (53.7 vs 55.2 points, p=0.40) or the exploratory physical and mental outcomes. Cardiac rehabilitation increased the occurrence of self-reported non-serious adverse events (11/72 vs 3/75, p=0.02). Cardiac rehabilitation after heart valve surgery significantly improves VO2 peak at 4 months but has no effect on mental health and other measures of exercise capacity and self-reported outcomes. Further research is needed to justify cardiac rehabilitation in this patient group. NCT01558765, Results. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  13. Circulating collagen metabolites, myocardial fibrosis and heart failure in aortic valve stenosis.

    Science.gov (United States)

    Kupari, Markku; Laine, Mika; Turto, Heikki; Lommi, Jyri; Werkkala, Kalervo

    2013-03-01

    Myocardial fibrosis predisposes to heart failure in aortic valve stenosis. The study aim was to determine the value of: (i) circulating collagen metabolites as biomarkers of left ventricular fibrosis and heart failure in aortic stenosis; and (ii) myocardial fibrosis as a predictor of postoperative outcome. Among a total of 132 patients (mean age 68 +/- 10 years) with severe aortic stenosis, measurements were made of circulating N-terminal propeptide of procollagen I (PINP), C-terminal telopeptide of collagen I (CITP) and N-terminal propeptide of procollagen III (PIIINP). Cardiac catheterization, echocardiography and a 6-min walk test were also performed. The aorta-to-coronary sinus concentration gradients of collagen metabolites were determined in 45 patients. Patients free from coronary artery disease (n = 85) underwent left ventricular biopsies for the assessment of myocardial fibrosis, one-year postoperative echocardiography and a 6-min walk test, and a long-term follow up for mortality. Neither peripheral collagen metabolites nor their transcardiac concentration gradients correlated with the extent of myocardial fibrosis. PIIINP demonstrated a net release from the heart, while PINP and CITP showed consistent falls in transcardiac concentrations that suggested extraction rather than release by the heart. Peripheral PIIINP correlated directly with the pulmonary wedge pressure (r = 0.50, p heart failure were found for CITP, but not for PINP. One-year postoperative changes in exercise capacity and left ventricular mass and function were independent of myocardial fibrosis, as was mortality over a median of 8.8 years. Circulating collagen metabolites are not reliable surrogate measures of myocardial fibrosis in aortic stenosis, despite CITP and PIIINP being associated strongly with heart failure and left ventricular dysfunction. The results of surgery, including long-term survival, appear independent of the extent of myocardial fibrosis.

  14. NT-proBNP and exercise capacity in adult patients with congenital heart disease and a prosthetic valve: a multicentre PROSTAVA study

    NARCIS (Netherlands)

    Schoonbeek, R.C.; Pieper, P.G.; Slooten, Y.J. van; Freling, H.G.; Sieswerda, G.T.; Dijk, A.P.J. van; Jongbloed, M.R.; Post, M.C.; Bouma, B.J.; Berger, R.M.; Ebels, T.; Melle, J.P. van

    2016-01-01

    OBJECTIVES: N-terminal Btype natriuretic peptide (NT-proBNP) is an important biomarker for the detection of heart failure. Adults with congenital heart disease (ACHD) and a prosthetic heart valve are at risk for heart failure. This study aimed to determine the value of NT-proBNP in ACHD patients wit

  15. NT-proBNP and exercise capacity in adult patients with congenital heart disease and a prosthetic valve : a multicentre PROSTAVA study

    NARCIS (Netherlands)

    Schoonbeek, R C; Pieper, P G; van Slooten, Y J; Freling, H G; Sieswerda, G T; van Dijk, A. P. J.; Jongbloed, M R M; Post, M. C.; Bouma, B. J.; Berger, R M F; Ebels, T; van Melle, J P

    2016-01-01

    OBJECTIVES: N-terminal B‑type natriuretic peptide (NT-proBNP) is an important biomarker for the detection of heart failure. Adults with congenital heart disease (ACHD) and a prosthetic heart valve are at risk for heart failure. This study aimed to determine the value of NT-proBNP in ACHD patients wi

  16. 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.)

  17. 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.

  18. Fluid-structure interaction of an aortic heart valve prosthesis driven by an animated anatomic left ventricle.

    Science.gov (United States)

    Le, Trung Bao; Sotiropoulos, Fotis

    2013-07-01

    We develop a novel large-scale kinematic model for animating the left ventricle (LV) wall and use this model to drive the fluid-structure interaction (FSI) between the ensuing blood flow and a mechanical heart valve prosthesis implanted in the aortic position of an anatomic LV/aorta configuration. The kinematic model is of lumped type and employs a cell-based, FitzHugh-Nagumo framework to simulate the motion of the LV wall in response to an excitation wavefront propagating along the heart wall. The emerging large-scale LV wall motion exhibits complex contractile mechanisms that include contraction (twist) and expansion (untwist). The kinematic model is shown to yield global LV motion parameters that are well within the physiologic range throughout the cardiac cycle. The FSI between the leaflets of the mechanical heart valve and the blood flow driven by the dynamic LV wall motion and mitral inflow is simulated using the curvilinear immersed boundary (CURVIB) method [1, 2] implemented in conjunction with a domain decomposition approach. The computed results show that the simulated flow patterns are in good qualitative agreement with in vivo observations. The simulations also reveal complex kinematics of the valve leaflets, thus, underscoring the need for patient-specific simulations of heart valve prosthesis and other cardiac devices.

  19. One year follow-up of the multi-centre European PARTNER transcatheter heart valve study

    Science.gov (United States)

    Lefèvre, Thierry; Kappetein, Ari Pieter; Wolner, Ernst; Nataf, Patrick; Thomas, Martyn; Schächinger, Volker; De Bruyne, Bernard; Eltchaninoff, Hélène; Thielmann, Matthias; Himbert, Dominique; Romano, Mauro; Serruys, Patrick; Wimmer-Greinecker, Gerhard

    2011-01-01

    Background Transcatheter aortic valve implantation (TAVI) has emerged as a new therapeutic option in high-risk patients with severe aortic stenosis. Aims PARTNER EU is the first study to evaluate prospectively the procedural and mid-term outcomes of transfemoral (TF) or transapical (TA) implantation of the Edwards SAPIEN® valve involving a multi-disciplinary approach. Methods and results Primary safety endpoints were 30 days and 6 months mortality. Primary efficacy endpoints were haemodynamic and functional improvement at 12 months. One hundred and thirty patients (61 TF, 69 TA), aged 82.1 ± 5.5 years were included. TA patients had higher logistic EuroSCORE (33.8 vs. 25.7%, P = 0.0005) and more peripheral disease (49.3 vs. 16.4%, P< 0.0001). Procedures were aborted in four TA (5.8%) and six TF cases (9.8%). Valve implantation was successful in the remaining patients in 95.4 and 96.4%, respectively. Thirty days and 6 months survival were 81.2 and 58.0% (TA) and 91.8 and 90.2% (TF). In both groups, mean aortic gradient decreased from 46.9 ± 18.1 to 10.9 ± 5.4 mmHg 6 months post-TAVI. In total, 78.1 and 84.8% of patients experienced significant improvement in New York Heart Association (NYHA) class, whereas 73.9 and 72.7% had improved Kansas City Cardiomyopathy Questionnaire (KCCQ) scores in TA and TF cohorts, respectively. Conclusion This first team-based multi-centre European TAVI registry shows promising results in high-risk patients treated by TF or TA delivery. Survival rates differ significantly between TF and TA groups and probably reflect the higher risk profile of the TA cohort. Optimal patient screening, approach selection, and device refinement may improve outcomes. PMID:21075775

  20. Cryopreserved amniotic fluid-derived cells: a lifelong autologous fetal stem cell source for heart valve tissue engineering.

    Science.gov (United States)

    Schmidt, Dörthe; Achermann, Josef; Odermatt, Bernhard; Genoni, Michele; Zund, Gregor; Hoerstrup, Simon P

    2008-07-01

    Fetal stem cells represent a promising cell source for heart valve tissue engineering. In particular, amniotic fluid-derived cells (AFDC) have been shown to lead to autologous fetal-like heart valve tissues in vitro for pediatric application. In order to expand the versatility of these cells also for adult application, cryopreserved AFDC were investigated as a potential life-long available cell source for heart valve tissue engineering. Human AFDC were isolated using CD133 magnetic beads, and then differentiated and analyzed. After expansion of CD133- as well as CD133+ cells up to passage 7, a part of the cells was cryopreserved. After four months, the cells were re-cultured and phenotyped by flow cytometry and immunohistochemistry, including expression of CD44, CD105, CD90, CD34, CD31, CD141, eNOS and vWF, and compared to their non-cryopreserved counterparts. The stem cell potential was investigated in differentiation assays. The viability of cryopreserved AFDC for heart valve tissue engineering was assessed by creating heart valve leaflets in vitro. After cryopreservation, amniotic fluid-derived CD133- and CD133+ cells retained their stem cell-like phenotype, expressing mainly CD44, CD90 and CD105. This staining pattern was comparable to that of their non-cryopreserved counterparts. Moreover, CD133- cells demonstrated differentiation potential into osteoblast-like and adipocyte-like cells. CD133+ cells showed characteristics of endothelial-like cells by eNOS, CD141 and beginning vWF expression. When used for the fabrication of heart valve leaflets, cryopreserved CD133- cells produced extracellular matrix elements comparable to their non-cryopreserved counterparts. Moreover, the resulting tissues showed a cellular layered tissue formation covered by functional endothelia. The mechanical properties were similar to those of tissues fabricated from non-cryopreserved cells. The study results suggest that the use of cell bank technology fetal amniotic fluid

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

    DEFF Research Database (Denmark)

    Sibilitz, Kirstine L.; Berg, Selina K.; Rasmussen, Trine B.

    2016-01-01

    -educational consultations (intervention) versus usual care without structured physical exercise or psycho-educational consultations (control). Primary outcome was physical capacity measured by VO2 peak and secondary outcome was self-reported mental health measured by Short Form-36. Results: 76% were men, mean age 62 years.......40) or the exploratory physical and mental outcomes. Cardiac rehabilitation increased the occurrence of self-reported non-serious adverse events (11/72 vs 3/75, p=0.02). Conclusions: Cardiac rehabilitation after heart valve surgery significantly improves VO2 peak at 4 months but has no effect on mental health and other......, with aortic (62%), mitral (36%) or tricuspid/pulmonary valve surgery (2%). Cardiac rehabilitation compared with control had a beneficial effect on VO2 peak at 4 months (24.8 mL/kg/min vs 22.5 mL/kg/min, p=0.045) but did not affect Short Form-36 Mental Component Scale at 6 months (53.7 vs 55.2 points, p=0...

  2. Estimation of viscous dissipative stresses induced by a mechanical heart valve using PIV data.

    Science.gov (United States)

    Li, Chi-Pei; Lo, Chi-Wen; Lu, Po-Chien

    2010-03-01

    Among the clinical complications of mechanical heart valves (MHVs), hemolysis was previously thought to result from Reynolds stresses in turbulent flows. A more recent hypothesis suggests viscous dissipative stresses at spatial scales similar in size to red blood cells may be related to hemolysis in MHVs, but the resolution of current instrumentation is insufficient to measure the smallest eddy sizes. We studied the St. Jude Medical (SJM) 27 mm valve in the aortic position of a pulsatile circulatory mock loop under physiologic conditions with particle image velocimetry (PIV). Assuming a dynamic equilibrium assumption between the resolved and sub-grid-scale (SGS) energy flux, the SGS energy flux was calculated from the strain rate tensor computed from the resolved velocity fields and the SGS stress was determined by the Smagorinsky model, from which the turbulence dissipation rate and then the viscous dissipative stresses were estimated. Our results showed Reynolds stresses up to 80 N/m2 throughout the cardiac cycle, and viscous dissipative stresses below 12 N/m2. The viscous dissipative stresses remain far below the threshold of red blood cell hemolysis, but could potentially damage platelets, implying the need for further study in the phenomenon of MHV hemolytic complications.

  3. New treatments using alginate in order to reduce the calcification of bovine bioprosthetic heart valve tissue.

    Science.gov (United States)

    Shanthi, C; Rao, K P

    1997-01-01

    Calcification limits the functional lifetime of cardiac valve substitutes fabricated from glutaraldehyde preserved bovine pericardium. Host factors, mainly younger age, and implant factors, mainly glutaraldehyde cross-linking, are implicated in the calcification process. Glutaraldehyde cross-linking is believed to activate the potential sites in the tissues for biocalcification. In the present work, we investigated the possibility of using alginate azide (AA) instead of glutaraldehyde for the preservation of pericardial tissues in order to enhance the durability of bioprosthetic heart valves. Grafting with poly(GMA-BA) copolymer to the alginate azide cross-linked pericardial (AACPC) tissue was carried out to obtain better stability, strength, and anticalcification properties. The strength property and thermal stability of the AA cross-linked tissues were studied. Calcification studies in rat subdermal models reveal that AA cross-linking reduces the calcification to negligible levels. After 30 days implantation, the calcium content was found to be 10.4 +/- 1.2 and 6.1 +/- 0.3 micrograms mg-1 for untreated AACPC and polymer grafted AACPC, respectively, compared to a value of 100 +/- 1.2 micrograms mg-1 calcium recorded for control glutaraldehyde cross-linked pericardial (GCPC) tissues.

  4. 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.

  5. Classification of Prolapsed Mitral Valve versus Healthy Heart from Phonocardiograms by Multifractal Analysis

    Directory of Open Access Journals (Sweden)

    Ana Gavrovska

    2013-01-01

    Full Text Available Phonocardiography has shown a great potential for developing low-cost computer-aided diagnosis systems for cardiovascular monitoring. So far, most of the work reported regarding cardiosignal analysis using multifractals is oriented towards heartbeat dynamics. This paper represents a step towards automatic detection of one of the most common pathological syndromes, so-called mitral valve prolapse (MVP, using phonocardiograms and multifractal analysis. Subtle features characteristic for MVP in phonocardiograms may be difficult to detect. The approach for revealing such features should be locally based rather than globally based. Nevertheless, if their appearances are specific and frequent, they can affect a multifractal spectrum. This has been the case in our experiment with the click syndrome. Totally, 117 pediatric phonocardiographic recordings (PCGs, 8 seconds long each, obtained from 117 patients were used for PMV automatic detection. We propose a two-step algorithm to distinguish PCGs that belong to children with healthy hearts and children with prolapsed mitral valves (PMVs. Obtained results show high accuracy of the method. We achieved 96.91% accuracy on the dataset (97 recordings. Additionally, 90% accuracy is achieved for the evaluation dataset (20 recordings. Content of the datasets is confirmed by the echocardiographic screening.

  6. Classification of Prolapsed Mitral Valve versus Healthy Heart from Phonocardiograms by Multifractal Analysis

    Science.gov (United States)

    Zajić, Goran; Reljin, Irini; Reljin, Branimir

    2013-01-01

    Phonocardiography has shown a great potential for developing low-cost computer-aided diagnosis systems for cardiovascular monitoring. So far, most of the work reported regarding cardiosignal analysis using multifractals is oriented towards heartbeat dynamics. This paper represents a step towards automatic detection of one of the most common pathological syndromes, so-called mitral valve prolapse (MVP), using phonocardiograms and multifractal analysis. Subtle features characteristic for MVP in phonocardiograms may be difficult to detect. The approach for revealing such features should be locally based rather than globally based. Nevertheless, if their appearances are specific and frequent, they can affect a multifractal spectrum. This has been the case in our experiment with the click syndrome. Totally, 117 pediatric phonocardiographic recordings (PCGs), 8 seconds long each, obtained from 117 patients were used for PMV automatic detection. We propose a two-step algorithm to distinguish PCGs that belong to children with healthy hearts and children with prolapsed mitral valves (PMVs). Obtained results show high accuracy of the method. We achieved 96.91% accuracy on the dataset (97 recordings). Additionally, 90% accuracy is achieved for the evaluation dataset (20 recordings). Content of the datasets is confirmed by the echocardiographic screening. PMID:23762185

  7. 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.

  8. 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.

  9. Aortic Valve Regurgitation

    Science.gov (United States)

    ... inside your heart that involves heart valves. Rheumatic fever. Rheumatic fever — a complication of strep throat and once a ... the United States — can damage the aortic valve. Rheumatic fever is still prevalent in developing countries but rare ...

  10. 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

  11. 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 <3.0 mg/dl (hazard ratio 7.22; p = 0.032) and emergent/urgent operation (hazard ratio 43.57; p = 0.035) as independent predictors of in-hospital 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 <10 mg/dl), low serum albumin, emergent/urgent operation, and infective endocarditis. Multivariate analysis using Cox proportional hazards modeling indicated low serum albumin (hazard ratio 2.12; p = 0.047) and emergent/urgent operation (hazard ratio 8.97; p = 0.0002) as independent predictors of remote 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.

  12. 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.)

  13. Cuspal dehiscence at a post and along the stent cloth in a bovine pericardium heart valve implanted for seven years.

    Science.gov (United States)

    Guidoin, Robert; Bes, Taniela Marli; Cianciulli, Tomas Francisco; Klein, Julianne; Li, Bin; Gauvin, Robert; Guzman, Randolph; Rochette-Drouin, Olivier; Germain, Lucie; Zhang, Ze

    2012-01-01

    A failing mitral valve prosthesis made from bovine pericardium was explanted from a 50-year-old patient. Preoperative transthoracic-echocardiography had confirmed severe mitral regurgitation due to structural failure of this HP Bio bovine pericardium heart valve prosthesis. The explanted device was examined macroscopically, by scanning electron microscopy (SEM), by light microscopy, and by transmission electron microscopy (TEM). Samples of unassembled patches of bovine pericardium were used as a pre-implantation control to better understand the changes that occurred in the structure of the pericardium following the 7 years of implantation. Examination confirmed complete dehiscence of a cusp along a valve post and the stent: This detached cusp was observed floating in the bloodstream at echocardiography. The fibrous pannus overgrowth was well developed along the stent and extended to the bottom of the cusps both on the inflow and the outflow sides. The fibrous panni were found to be poorly adhesive to the pericardium cusps and had become stiff, thus impairing the opening and closure of the valve. The structure of the pericardium cusps was severely deteriorated compared to the control bovine pericardium tissue samples. The collagen bundles were frequently broken and more stretched in the explanted device, lacking the wavy histological pattern of normal collagen fibers. However, the tissues were devoid of any calcification. In conclusion, the failure mode of this valve was the dehiscence of a cusp from a valve post and along the stent cloth in the absence calcification.

  14. 组织工程心脏瓣膜的研究进展%Advancements in Tissue Engineering Heart Valves

    Institute of Scientific and Technical Information of China (English)

    傅杰

    2011-01-01

    Valve replacement is currently still the most effective treatment option for valvular heart disease. However, clinical efficacy of artificial heart valves is far from satisfactory. The discovery and development of tissue engineering opens the door to many new alternatives. This article reviews advancements in tissue engineering heart valves including the selection of seed cells, the choice of scaffold material, the methods of valve formation in vitro, the efficacy of using animals, and clinical application.%心脏瓣膜置换术仍然是当前治疗心脏瓣膜病最有效的治疗方法,但目前临床应用的人工心脏瓣膜疗效却不尽如人意.随着组织工程学的兴起与发展,组织工程心脏瓣膜的研究越来越受到关注并成为研究的热点.现对组织工程心脏瓣膜研究在种子细胞的选择、支架材料的选择、瓣膜体外构建方法、动物实验与临床应用等方面取得的进展,进行综述.

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

    Science.gov (United States)

    Falk, Torkel; Jönsson, Lennart; Olsen, Lisbeth H; Pedersen, Henrik D

    2006-01-01

    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. 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. Dogs with congestive heart failure had significantly more arterial narrowing in the left ventricle (P fibrosis in the left ventricle (P heart failure (P valve disease have significantly more arterial changes in the myocardium, lung, and kidney, and significantly more fibrosis in the myocardium than control dogs. This could have important implications in the management of myxomatous mitral valve disease and raises interesting questions about the occurrence and importance of intramural small vessel disease in humans with primary mitral valve prolapse.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. Comparison of the Performance of the Warfarin Pharmacogenetics Algorithms in Patients with Surgery of Heart Valve Replacement and Heart Valvuloplasty.

    Science.gov (United States)

    Xu, Hang; Su, Shi; Tang, Wuji; Wei, Meng; Wang, Tao; Wang, Dongjin; Ge, Weihong

    2015-09-01

    A large number of warfarin pharmacogenetics algorithms have been published. Our research was aimed to evaluate the performance of the selected pharmacogenetic algorithms in patients with surgery of heart valve replacement and heart valvuloplasty during the phase of initial and stable anticoagulation treatment. 10 pharmacogenetic algorithms were selected by searching PubMed. We compared the performance of the selected algorithms in a cohort of 193 patients during the phase of initial and stable anticoagulation therapy. Predicted dose was compared to therapeutic dose by using a predicted dose percentage that falls within 20% threshold of the actual dose (percentage within 20%) and mean absolute error (MAE). The average warfarin dose for patients was 3.05±1.23mg/day for initial treatment and 3.45±1.18mg/day for stable treatment. The percentages of the predicted dose within 20% of the therapeutic dose were 44.0±8.8% and 44.6±9.7% for the initial and stable phases, respectively. The MAEs of the selected algorithms were 0.85±0.18mg/day and 0.93±0.19mg/day, respectively. All algorithms had better performance in the ideal group than in the low dose and high dose groups. The only exception is the Wadelius et al. algorithm, which had better performance in the high dose group. The algorithms had similar performance except for the Wadelius et al. and Miao et al. algorithms, which had poor accuracy in our study cohort. The Gage et al. algorithm had better performance in both phases of initial and stable treatment. Algorithms had relatively higher accuracy in the >50years group of patients on the stable phase. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Mitral valve regurgitation

    Science.gov (United States)

    ... and dentist if you have a history of heart valve disease or congenital heart disease before treatment. Some people ... the middle Heart, front view References Carabello BA. Valvular heart disease. In: Goldman L, Schafer AI, eds. Goldman's Cecil ...

  2. 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.

  3. In vivo and in vitro release of lysozyme from cross-linked gelatin hydrogels : a model system for the delivery of antibacterial proteins from prosthetic heart valves

    NARCIS (Netherlands)

    Kuijpers, AJ; van Wachem, PB; van Luyn, MJA; Engbers, GHM; Krijgsveld, J; Zaat, SAJ; Feijen, J

    2000-01-01

    Prosthetic valve endocarditis may be reduced by the local delivery of antibacterial proteins from the Dacron sewing ring of a prosthetic heart valve. Dacron discs were treated with a carbon dioxide gas plasma to improve the hydrophilicity and thereby enabling homogeneous impregnation with gelatin ty

  4. 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

  5. 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

  6. 人造机械瓣心音的分析研究%Analysis of Heart Sounds with Artificial Mechanical Prosthetic Heart Valves

    Institute of Scientific and Technical Information of China (English)

    张地; 姚尖平; 杜明辉; 杨嵩

    2011-01-01

    在一些致命性心脏病的诊断中,心音听诊是最有效也是应用得最成功的手段之一.鉴于目前机械瓣的使用非常普遍,研究简单有效的机械瓣病变判别方法对于临床诊断来讲具有重要意义.运用希尔波特-黄变换(HHT),针对不同的机械瓣心音进行分析,并设计一种基于Hilbert边界谱特征的提取方法,结合线性判别分析(LDA),对不同的机械瓣心音进行分类.同时,与基于局部最优基特征的分类器分类结果进行比较.分析结果表明,机械瓣心音的各阶Hilbert边界谱具有非常明显不同的分布,基于HHT的分类器识别率达到了97.3%,较基于局部最优基特征分类器的识别率(91.3%)更高.对于人造机械瓣心音而言,HHT是一种有效的分析处理手段.%Auscultation is a widely used efficient technique by cardiologists for detecting some deadly heart diseases. Since the mechanical prosthetic heart valves are widely used today, it is important to develop a simple and efficient method to detect abnormal mechanical valves. In this paper, Hilbert-Huang transform ( HHT) was applied to analyze the heart sounds with different kinds of mechanical prosthetic valves. A Hilbert marginal spectral based feature extraction procedure was also developed. Combined with linear discriminant analysis ( LDA) , the extracted features were used to classify different kinds of heart sounds for mechanical prosthetic heart valves. Experimental results showed that the spectrum of different heart sounds were significantly different. The proposed classifier achieved a recognition rate of 97. 3% , higher than the one based on local discriminant bases (91. 3% ). It is demonstrated that HHT is an efficient analyzing technique for artificial heart valve sounds.

  7. 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.

  8. Percutaneous Transcatheter Mitral Valve Replacement: Patient-specific Three-dimensional Computer-based Heart Model and Prototyping.

    Science.gov (United States)

    Vaquerizo, Beatriz; Theriault-Lauzier, Pascal; Piazza, Nicolo

    2015-12-01

    Mitral regurgitation is the most prevalent valvular heart disease worldwide. Despite the widespread availability of curative surgical intervention, a considerable proportion of patients with severe mitral regurgitation are not referred for treatment, largely due to the presence of left ventricular dysfunction, advanced age, and comorbid illnesses. Transcatheter mitral valve replacement is a promising therapeutic alternative to traditional surgical valve replacement. The complex anatomical and pathophysiological nature of the mitral valvular complex, however, presents significant challenges to the successful design and implementation of novel transcatheter mitral replacement devices. Patient-specific 3-dimensional computer-based models enable accurate assessment of the mitral valve anatomy and preprocedural simulations for transcatheter therapies. Such information may help refine the design features of novel transcatheter mitral devices and enhance procedural planning. Herein, we describe a novel medical image-based processing tool that facilitates accurate, noninvasive assessment of the mitral valvular complex, by creating precise three-dimensional heart models. The 3-dimensional computer reconstructions are then converted to a physical model using 3-dimensional printing technology, thereby enabling patient-specific assessment of the interaction between device and patient. It may provide new opportunities for a better understanding of the mitral anatomy-pathophysiology-device interaction, which is of critical importance for the advancement of transcatheter mitral valve replacement.

  9. 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.

  10. 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

  11. Surgical treatment for left-sided heart valve disease in a national reference hospital in Lima, Peru

    OpenAIRE

    Vasquez, Julio C.; Portneuf Medical Center. Idaho, EE. UU. Médico, cirujano de tórax y cardiovascular.; Barrantes, Ciro A.; Hospital Nacional Guillermo Almenara. Lima, Perú. médico, cardiólogo.; Peralta, Julio E.; Programa de Cirugía de Tórax y Cardiovascular “Efraín Montesinos Mosqueira”, Hospital Nacional Dos de Mayo. Lima, Perú. Médico, cirujano de tórax y cardiovascular.; Rojas, Luis E.; Programa de Cirugía de Tórax y Cardiovascular “Efraín Montesinos Mosqueira”, Hospital Nacional Dos de Mayo. Lima, Perú. Médico, cirujano de tórax y cardiovascular.

    2014-01-01

    Objectives. To describe the preoperative, intraoperative and postoperative characteristics of patients with left-sided heart valve disease treated in the thoracic and cardiovascular surgery service of a national reference hospital; as well as to describe the occurrence of thromboembolic and bleeding events in these patients. Materials and methods. A retrospective longitudinal study was carried out, which included 185 patients who underwert surgery between 1999 and 2006 at the Hospital Nac...

  12. 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...... and pulmonary artery. Results: Dogs with congestive heart failure had significantly more arterial narrowing in the left ventricle (Pkidney (p...-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...

  13. Measurements of steady flow through a bileaflet mechanical heart valve using stereoscopic PIV.

    Science.gov (United States)

    Hutchison, Chris; Sullivan, Pierre; Ethier, C Ross

    2011-03-01

    Computational modeling of bileaflet mechanical heart valve (BiMHV) flow requires experimentally validated datasets and improved knowledge of BiMHV fluid mechanics. In this study, flow was studied downstream of a model BiMHV in an axisymmetric aortic sinus using stereoscopic particle image velocimetry. The inlet flow was steady and the Reynolds number based on the aortic diameter was 7600. Results showed the out-of-plane velocity was of similar magnitude as the transverse velocity. Although additional studies are needed for confirmation, analysis of the out-of-plane velocity showed the possible presence of a four-cell streamwise vortex structure in the mean velocity field. Spatial data for all six Reynolds stress components were obtained. Reynolds normal stress profiles revealed similarities between the central jet and free jets. These findings are important to BiMHV flow modeling, though clinical relevance is limited due to the idealized conditions chosen. To this end, the dataset is publicly available for CFD validation purposes.

  14. Mechanism of Microbubble Growth at Mitral Mechanical Heart Valve (MHV) Closure

    Science.gov (United States)

    Rambod, Edmond; Beizaie, Masoud; Shusser, Michael; Gharib, Morteza

    1999-11-01

    The growth mechanism of microbubbles at mitral MHV closure has been experimentally studied. In the heart, some of the tiny bubbles grow explosively and form larger and persistent bubbles. An experimental set-up was designed to allow the passage of micron-size bubbles through an 80 micron-wide slot, simulating a typical gap between the housing ring and the occluders in MHV. The bubbles were generated using an air-liquid dispenser and were delivered to the system via a 250 micron-diameter hypedermic needle positioned vertically near the slot. A solenoid valve was used to deliver a 10cc volume of liquid in 25ms time through the slot. High-speed imaging was used to study the impact of flow through the slot on bubble growth. The velocity of liquid through the slot was assessed to be in the range of 12-15 m/s. Our observations confirmed the rapid and drastic growth of microbubbles following their passage through the narrow slot, due to pressure drop. Vortices, which were induced by flow separation on the downstream of the slot, caused the grown bubbles to shatter and form more stable bubbles.

  15. Recellularization of biological heart valves with human vascular cells: in vitro hemocompatibility assessment.

    Science.gov (United States)

    Schopka, Simon; Schmid, Franz-Xaver; Hirt, Stephan; Birnbaum, Dietrich E; Schmid, Christof; Lehle, Karla

    2009-01-01

    Coverage of cardiovascular bioprostheses with autologous endothelium is used for the purpose of improving blood compatibility. The aim of our study was to analyze endothelialization potential of glutaraldehyde-fixed heart valves, cellular functions of seeded endothelial cells (EC), and the impact of a two-stage seeding protocol using human vascular fibroblasts (FB) and EC from saphenous veins (HSVEC) on cellular functional properties in vitro. Adherence and morphology of adhered cells were assessed by scanning electronic microscopy and immunohistochemistry. Reproducible, complete surface coverage with EC was established on decellularized and glutaraldehyde-fixed bovine pericardium. Analyzing functional properties of cells directly adhered to biomaterial revealed nonproliferative cells, which were capable of inflammatory stimulation in terms of TNF-induced increase in interleukin-6 secretion and adhesion of inflammatory cells. Furthermore, EC showed sustained antithrombotic properties quantified by platelet adhesion onto EC and prostacyclin secretion by EC. Preseeding with vascular fibroblasts using a two-stage seeding protocol induced EC proliferation and improved inflammatory and anti-thrombotic functions. Cardiovascular biomaterials differ significantly in their potential to allow for adhesion of human EC. Successfully endothelialized biomaterial, however, revealed cellular properties which are likely to be favorable to improving performance of biomaterials. Two-stage seeding adds regenerative potential and improves cell functions of adherent EC.

  16. Body image after heart transplantation compared to mechanical aortic valve insertion.

    Science.gov (United States)

    Hartmann, Armin; Heilmann, Claudia; Kaps, Josefine; Beyersdorf, Friedhelm; Zeh, Wolfgang; Albert, Wolfgang; Wirsching, Michael; Fritzsche, Kurt; Joos, Andreas

    2017-11-01

    Heart transplantation (HT) obviously affects body image and integrity. However, there are very few empirical data post-transplant. In a cross-sectional study, 57 HT patients were compared with 47 subjects with mechanical aortic valve replacement (AVR) using the Dresden-Body-Image questionnaire (DKB) and specific questions regarding integration of the organ/device. In addition, affective symptoms and quality of life (QoL) were assessed (12-Item Short-Form Health Survey and Hospital Anxiety and Depression Scale, HADS). DKB-35 scores did not differ. HT patients scored higher than AVR on specific questions regarding integration of the organ/device. AVR patients showed more affective disturbance and lower mental QoL than HT subjects. Affective scores correlated negatively with body image scores. Seventeen percent of all patients showed psychological distress (HADS scores >8). HT patients integrated the new organ well - and even better than AVR subjects did with the device. In general, our data corroborate a good adaptation process, in particular in HT patients. Similar to other reported data, a subgroup of 15-20% of patients shows stronger mental distress, including body image problems. These must be identified and treated by professionals. Patients with AVR deserve more attention in the future.

  17. Laser induced periodic surface structures on pyrolytic carbon prosthetic heart valve

    Science.gov (United States)

    Stepak, Bogusz D.; Łecka, Katarzyna M.; Płonek, Tomasz; Antończak, Arkadiusz J.

    2016-12-01

    Laser-induced periodic surface structures (LIPSS) can appear in different forms such as ripples, grooves or cones. Those highly periodic wavy surface features which are frequently smaller than incident light wavelength bring possibility of nanostructuring of many different materials. Furthermore, by changing laser parameters one can obtain wide spectrum of periodicities and geometries. The aim of this research was to determine possibility of nanostructuring pyrolytic carbon (PyC) heart valve leaflets using different irradiation conditions. The study was performed using two laser sources with different pulse duration (15 ps, 450 fs) as well as different wavelengths (1064, 532, 355 nm). Both low and high spatial frequency LIPSS were observed for each set of irradiation parameters. In case femtosecond laser pulses we obtained deep subwavelength ripple period which was even ten times smaller than applied wavelength. Obtained ripple period was ranging from 90 up to 860 nm. Raman spectra revealed the increase of disorder after laser irradiation which was comparable for both pico- and femtosecond laser.

  18. Comparison of in vitro flows past a mechanical heart valve in anatomical and axisymmetric aorta models

    Science.gov (United States)

    Haya, Laura; Tavoularis, Stavros

    2017-06-01

    Flow characteristics past a bileaflet mechanical heart valve were measured under physiological flow conditions in a straight tube with an axisymmetric expansion, similar to vessels used in previous studies, and in an anatomical model of the aorta. We found that anatomical features, including the three-lobed sinus and the aorta's curvature affected significantly the flow characteristics. The turbulent and viscous stresses were presented and discussed as indicators for potential blood damage and thrombosis. Both types of stresses, averaged over the two axial measurement planes, were significantly lower in the anatomical model than in the axisymmetric one. This difference was attributed to the lower height-to-width ratio and more gradual contraction of the anatomical aortic sinus. The curvature of the aorta caused asymmetries in the velocity and stress distributions during forward flow. Secondary flows resulting from the aorta's curvature are thought to have redistributed the fluid stresses transversely, resulting in a more homogeneous stress distribution in the anatomical aortic root than in the axisymmetric root. The results of this study demonstrate the importance of modelling accurately the aortic geometry in experimental and computational studies of prosthetic devices. Moreover, our findings suggest that grafts used for aortic root replacement should approximate as closely as possible the shape of the natural sinuses.

  19. Estimation of torque on mechanical heart valves due to magnetic resonance imaging including an estimation of the significance of the Lenz effect using a computational model

    Energy Technology Data Exchange (ETDEWEB)

    Robertson, Neil M. [44 Ardgowan Street, Greenock PA16 8EL (United Kingdom). E-mail: neil.robertson at physics.org; Diaz-Gomez, Manuel [Plaza Alcalde Horacio Hermoso, 2, 3-A 41013 Seville (Spain). E-mail: manolo-diaz at latinmail.com; Condon, Barrie [Department of Clinical Physics, Institute of Neurological Sciences, Glasgow G51 4TF (United Kingdom). E-mail: barrie.condon at udcf.gla.ac.uk

    2000-12-01

    Mitral and aortic valve replacement is a procedure which is common in cardiac surgery. Some of these replacement valves are mechanical and contain moving metal parts. Should the patient in whom such a valve has been implanted be involved in magnetic resonance imaging, there is a possible dangerous interaction between the moving metal parts and the static magnetic field due to the Lenz effect. Mathematical models of two relatively common forms of single-leaflet valves have been derived and the magnitude of the torque which opposes the motion of the valve leaflet has been calculated for a valve disc of solid metal. In addition, a differential model of a ring-strengthener valve type has been considered to determine the likely significance of the Lenz effect in the context of the human heart. For common magnetic field strengths at present, i.e. 1 to 2 T, the effect is not particularly significant. However, there is a marked increase in back pressure as static magnetic field strength increases. There are concerns that, since field strengths in the range 3 to 4 T are increasingly being used, the Lenz effect could become significant. At 5 to 10 T the malfunction of the mechanical heart valve could cause the heart to behave as though it is diseased. For unhealthy or old patients this could possibly prove fatal. (author)

  20. Mitral implant of the Inovare transcatheter heart valve in failed surgical bioprostheses: a novel alternative for valve-in-valve procedures.

    Science.gov (United States)

    Gaia, Diego Felipe; Braz, Ademir Massarico; Simonato, Matheus; Dvir, Danny; Breda, João Roberto; Ribeiro, Gustavo Calado; Ferreira, Carolina Baeta; Souza, José Augusto Marcondes; Buffolo, Enio; Palma, José Honório

    2017-04-01

    Reoperative procedure for the treatment of a failed mitral bioprosthesis is associated with considerable risk. In some cases, mortality is high and might contraindicate the benefit of the procedure. The minimally invasive valve-in-valve (ViV) transcatheter mitral valve implant offers an alternative less-invasive approach, reducing morbidity and mortality. The objective of this paper was to evaluate the mitral ViV approach using the Braile Inovare prosthesis. The transcatheter balloon-expandable Braile Inovare prosthesis was used in 12 cases. Procedures were performed in a hybrid operating room, under fluoroscopic and echocardiographic control. Through left minithoracotomy, the prostheses were implanted through the cardiac apex. Serial echocardiographic and clinical examinations were performed. Follow-up varied from 1 to 30 months. A total of 12 transapical mitral ViV procedures were performed. Patients had a mean age of 61.6 ± 9.9 years and 92% were women. Mean logistic EuroSCORE was 20.1%. Successful valve implantation was possible in all cases. In one case, a right lateral thoracotomy was performed for the removal of an embolized prosthesis. There was no operative mortality. Thirty-day mortality was 8.3%. Ejection fraction was preserved after the implant (66.7%; 64.8%; P  = 0.3). The mitral gradient showed a significant reduction (11 mmHg; 6 mmHg; P  implant in a failed bioprosthesis is an effective procedure. This possibility might alter prosthesis selection in the future initial surgical prosthesis selection, favouring bioprostheses. Further large trials should explore its safety.

  1. Biaxial stress relaxation of semilunar heart valve leaflets during simulated collagen catabolism: Effects of collagenase concentration and equibiaxial strain state.

    Science.gov (United States)

    Huang, Siyao; Huang, Hsiao-Ying Shadow

    2015-10-01

    Heart valve leaflet collagen turnover and remodeling are innate to physiological homeostasis; valvular interstitial cells routinely catabolize damaged collagen and affect repair. Moreover, evidence indicates that leaflets can adapt to altered physiological (e.g. pregnancy) and pathological (e.g. hypertension) mechanical load states, tuning collagen structure and composition to changes in pressure and flow. However, while valvular interstitial cell-secreted matrix metalloproteinases are considered the primary effectors of collagen catabolism, the mechanisms by which damaged collagen fibers are selectively degraded remain unclear. Growing evidence suggests that the collagen fiber strain state plays a key role, with the strain-dependent configuration of the collagen molecules either masking or presenting proteolytic sites, thereby protecting or accelerating collagen proteolysis. In this study, the effects of equibiaxial strain state on collagen catabolism were investigated in porcine aortic valve and pulmonary valve tissues. Bacterial collagenase (0.2 and 0.5 mg/mL) was utilized to simulate endogenous matrix metalloproteinases, and biaxial stress relaxation and biochemical collagen concentration served as functional and compositional measures of collagen catabolism, respectively. At a collagenase concentration of 0.5 mg/mL, increasing the equibiaxial strain imposed during stress relaxation (0%, 37.5%, and 50%) yielded significantly lower median collagen concentrations in the aortic valve (p = 0.0231) and pulmonary valve (p = 0.0183), suggesting that relatively large strain magnitudes may enhance collagen catabolism. Collagen concentration decreases were paralleled by trends of accelerated normalized stress relaxation rate with equibiaxial strain in aortic valve tissues. Collectively, these in vitro results indicate that biaxial strain state is capable of affecting the susceptibility of valvular collagens to catabolism, providing a basis for further investigation of

  2. A novel left heart simulator for the multi-modality characterization of native mitral valve geometry and fluid mechanics.

    Science.gov (United States)

    Rabbah, Jean-Pierre; Saikrishnan, Neelakantan; Yoganathan, Ajit P

    2013-02-01

    Numerical models of the mitral valve have been used to elucidate mitral valve function and mechanics. These models have evolved from simple two-dimensional approximations to complex three-dimensional fully coupled fluid structure interaction models. However, to date these models lack direct one-to-one experimental validation. As computational solvers vary considerably, experimental benchmark data are critically important to ensure model accuracy. In this study, a novel left heart simulator was designed specifically for the validation of numerical mitral valve models. Several distinct experimental techniques were collectively performed to resolve mitral valve geometry and hemodynamics. In particular, micro-computed tomography was used to obtain accurate and high-resolution (39 μm voxel) native valvular anatomy, which included the mitral leaflets, chordae tendinae, and papillary muscles. Three-dimensional echocardiography was used to obtain systolic leaflet geometry. Stereoscopic digital particle image velocimetry provided all three components of fluid velocity through the mitral valve, resolved every 25 ms in the cardiac cycle. A strong central filling jet (V ~ 0.6 m/s) was observed during peak systole with minimal out-of-plane velocities. In addition, physiologic hemodynamic boundary conditions were defined and all data were synchronously acquired through a central trigger. Finally, the simulator is a precisely controlled environment, in which flow conditions and geometry can be systematically prescribed and resultant valvular function and hemodynamics assessed. Thus, this work represents the first comprehensive database of high fidelity experimental data, critical for extensive validation of mitral valve fluid structure interaction simulations.

  3. 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.).

  4. Harnessing osteopontin and other natural inhibitors to mitigate ectopic calcification of bioprosthetic heart valve material

    Science.gov (United States)

    Ohri, Rachit

    Dystrophic calcification has been the long-standing major cause of bioprosthetic heart valve failure, and has been well studied in terms of the underlying causative mechanisms. Such understanding has yielded several anti-calcification strategies involving biomaterial modification at the preparation stage: chemical alteration, extraction of calcifiable components, or material modification with small-molecule anti-calcific agents. However, newer therapeutic opportunities are offered by the growing illustration of the pathology as a dynamic, actively regulated process involving several gene products, such as osteopontin (OPN), matrix-gla protein (MGP) and glycosaminoglycans (GAGs). Osteopontin, a multi-functional matricellular glycosylated phosphoprotein has emerged as a prime candidate for the role of an in vivo inhibitor of ectopic calcification with two putative mechanisms: crystal poisoning and mineral-dissolution. The full therapeutic realization of its potential necessitates a better understanding of the mechanisms of anti-calcification by osteopontin, as well as appropriate in vivo models in which to evaluate its efficacy, potency and molecular mechanisms. In this work, we pursued the development and characterization of a reliable in vivo model with the OPN-null mouse to simulate the calcification of bioprosthetic valve material, namely glutaraldehyde-fixed bovine pericardium (GFBP) tissue. Subsequently, we used the calcification model to evaluate hypotheses based on the anti-calcific potential of osteopontin. Several modes of administering exogenous OPN to the implant site in OPN-null mice were explored, including soluble injected OPN, OPN covalently immobilized on the biomaterial, and OPN adsorbed onto the biomaterial. An investigation of the structure-function aspects of the anti-calcific ability of OPN was also pursued in the in vivo model. The OPN-null mouse was also used as an in vivo test-bed to evaluate the anti-calcific potential of other biomolecules

  5. Three-dimensional quantitative micromorphology of pre- and post-implanted engineered heart valve tissues.

    Science.gov (United States)

    Eckert, Chad E; Mikulis, Brandon T; Gottlieb, Danielle; Gerneke, Dane; LeGrice, Ian; Padera, Robert F; Mayer, John E; Schoen, Frederick J; Sacks, Michael S

    2011-01-01

    There is a significant gap in our knowledge of engineered heart valve tissue (EHVT) development regarding detailed three-dimensional (3D) tissue formation and remodeling from the point of in vitro culturing to full in vivo function. As a step toward understanding the complexities of EHVT formation and remodeling, a novel serial confocal microscopy technique was employed to obtain 3D microstructural information of pre-implant (PRI) and post-implant for 12 weeks (POI) EHVT fabricated from PGA:PLLA scaffolds and seeded with ovine bone-marrow-derived mesenchymal stem cells. Custom scaffold fiber tracking software was developed to quantify scaffold fiber architectural features such as length, tortuosity, and minimum scaffold fiber-fiber separation distance and scaffold fiber orientation was quantified utilizing a 3D fabric tensor. In addition, collagen and cellular density of ovine pulmonary valve leaflet tissue were also analyzed for baseline comparisons. Results indicated that in the unseeded state, scaffold fibers formed a continuous, oriented network. In the PRI state, the scaffold showed some fragmentation with a scaffold volume fraction of 7.79%. In the POI specimen, the scaffold became highly fragmented, forming a randomly distributed short fibrous network (volume fraction of 2.03%) within a contiguous, dense collagenous matrix. Both PGA and PLLA scaffold fibers were observed in the PRI and POI specimens. Collagen density remained similar in both PRI and POI specimens (74.2 and 71.5%, respectively), though the distributions in the transmural direction appeared slightly more homogenous in the POI specimen. Finally, to guide future 2D histological studies for large-scale studies (since acquisition of high-resolution volumetric data is not practical for all specimens), we investigated changes in relevant collagen and scaffold metrics (collagen density and scaffold fiber orientation) with varying section spacing. It was found that a sectioning spacing up to 25

  6. [Significance and Expressions of MMP-1, TIMP-1 and TGF-β1 in Valve Tissue of Rheumatic Heart Disease].

    Science.gov (United States)

    Yu, Yi; Li, Zeng-Qi; Chen, Kun; Zhan, Ping; Liao, Jian; Ruan, Qin-Yun

    2017-01-01

    To explore expressions of matrix metalloproteinase-1 (MMP-1), tissue inhibitor of metalloproteinases-1 (TIMP-1) and transforming growth factor-β1 (TGF-β1) in valve tissue of rheumatic heart disease (RHD), and to analyzed their roles in RHD. The expressions of MMP-1, TIMP-1 and TGF-β1 proteins and mRNAs were tested by Western blot and RT-PCR methods in valve tissues in participants with (experimental group, n=30) and without RHD (control group, n=15). Collagen fibers were detected by Masson staining, and collagen volume fraction (CVF) was caculated. The correlations of CVF and the expressions of MMP-1, TIMP-1 and TGF-β1 were analyzed. The collagen fibers, CVF, and the protein and mRNA expressions of MMP-1 and TGF-β1 in experimental group were higher than those in control group, while the protein and mRNA expressions of TIMP-1 in experimental group were lower than those in control group. The expression of TIMP-1 was negatively correlated with TGF-β1 and CVF in valve tissues, while MMP-1 was positively correlated with them. The expression of TGF-β1 was positively correlated with CVF in valve tissues. MMP-1, TIMP-1 and TGF-β1 contribute to the progression of fibrosis in RHD.

  7. Unsteady fluid dynamics of several mechanical prosthetic heart valves using a two component laser Doppler anemometer system.

    Science.gov (United States)

    Akutsu, T; Modi, V J

    1997-10-01

    Five typical mechanical heart valves (Starr-Edwards, Björk-Shiley convexo-concave (c-c), Björk-Shiley monostrut, Bicer-Val, and St. Jude Medical) were tested in the mitral position under the pulsatile flow condition. The test program included measurements of velocity and turbulent stresses at 5 downstream locations. The study was carried out using a sophisticated cardiac simulator in conjunction with a highly sensitive 2 component laser Doppler anemometer (LDA) system. The continuous monitoring of parametric time histories revealed useful details about the complex flow and helped to establish the locations and times of the peak parameter values. Based upon the nondimensional presentation of data, the following general conclusions can be made. First, all the 5 valve designs created elevated turbulent stresses during the accelerating and peak flow phases, presenting the possibility of thromboembolism and perhaps hemolysis. Second, the difference in valve configuration seemed to affect the flow characteristics; third, the bileaflet design of the St. Jude valve appeared to create a lower turbulence stress level.

  8. Evaluation of shear stress accumulation on blood components in normal and dysfunctional bileaflet mechanical heart valves using smoothed particle hydrodynamics.

    Science.gov (United States)

    Shahriari, S; Maleki, H; Hassan, I; Kadem, L

    2012-10-11

    Evaluating shear induced hemodynamic complications is one of the major concerns in design of the mechanical heart valves (MHVs). The monitoring of these events relies on both numerical simulations and experimental measurements. Currently, numerical approaches are mainly based on a combined Eulerian-Lagrangian approach. A more straightforward evaluation can be based on the Lagrangian analysis of the whole blood. As a consequence, Lagrangian meshfree methods are more adapted to such evaluation. In this study, smoothed particle hydrodynamics (SPH), a fully meshfree particle method originated to simulate compressible astrophysical flows, is applied to study the flow through a normal and a dysfunctional bileaflet mechanical heart valves (BMHVs). The SPH results are compared with the reference data. The accumulation of shear stress patterns on blood components illustrates the important role played by non-physiological flow patterns and mainly vortical structures in this issue. The statistical distribution of particles with respect to shear stress loading history provides important information regarding the relative number of blood components that can be damaged. This can be used as a measure of the response of blood components to the presence of the valve implant or any implantable medical device. This work presents the first attempt to simulate pulsatile flow through BMHVs using SPH method.

  9. 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.

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

    NARCIS (Netherlands)

    Tanis, Wilco; Suchá, Dominika; Laufer, Ward; Habets, Jesse; van Herwerden, Lex A.; Symersky, Petr; Chamuleau, Steven; Budde, Ricardo P J

    2015-01-01

    Objectives: 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

  11. Prognostic value of heart valve calcifications for cardiovascular events in a lung cancer screening population

    NARCIS (Netherlands)

    Willemink, Martin J.; Takx, Richard A. P.; Isgum, Ivana; de Koning, Harry J.; Oudkerk, Matthijs; Mali, Willem P. Th. M.; Budde, Ricardo P. J.; Leiner, Tim; Vliegenthart, Rozemarijn; de Jong, Pim A.

    2015-01-01

    To assess the prognostic value of aortic valve and mitral valve/annulus calcifications for cardiovascular events in heavily smoking men without a history of cardiovascular disease. Heavily smoking men without a cardiovascular disease history who underwent non-contrast-enhanced low-radiation-dose che

  12. 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

  13. Valvular heart disease: assessment of valve morphology and quantification using MR

    Energy Technology Data Exchange (ETDEWEB)

    Schwitter, J. [Div. of Cardiology and Cardiovascular, MR Center, Univ. Hospital Zurich (Switzerland)

    2000-06-01

    For clinical evaluation and decision-making in patients with valvular heart disease, the diagnostic armamentarium expands steadily. This evolution makes it difficult to choose the most appropriate approach for a specific valvular lesion. It may also reflect our uncertainty of what are the findings that best predict clinical outcome of patients, e. g. after surgery. Accordingly, for each type of valvular lesion, some pathophysiological considerations are stated in order to derive the most important measures that would allow optimal guidance of patients. Based on these considerations the value of an MR study is discussed for each valvular lesion. Newest advances in MR technology allow for highly accurate measurements of regurgitant volumes and hence, MR may be the method of choice for a quantitative evaluation of regurgitant valves. For assessment of stenosis severity, measurement of transvalvular pressure gradient is an appropriate measure and MR may not confer benefits over echocardiography, provided the ultrasound window is adequate (and stroke volume is in the normal range). With respect to surgical treatment, valvular morphology is of pivotal importance, particularly for the mitral valve, and echocardiography still appears to be the first line method. Little data relate lesion severity and/or morphology to clinical outcome. Conversely, the extent of cardiac adaptation to pressure- and/or volume-overload, i. e. ventricular remodeling, is a strong predictor of outcome, and is therefore most important for final judgement of the patient. For assessment of left and right ventricular remodeling, echocardiography typically provides all the necessary information. However, in special cases with discrepant findings, with inadequate ultrasound window, or in the preoperative work-up, MR may provide important information regarding cardiac adaptation to valvular lesion. (orig.) [German] Das diagnostische Repertoire zur Evaluation von Klappenvitien ist in den letzten Jahren

  14. Pulmonary valve stenosis

    Science.gov (United States)

    ... valvuloplasty - pulmonary Images Heart valves References Carabello BA. Valvular heart disease. In: Goldman L, Schafer AI, eds. Goldman's Cecil ... Saunders; 2016:chap 69. Otto CM, Bownow RO. Valvular heart disease. In: Mann DL, Zipes DP, Libby P, Bonow ...

  15. Successful Treatment of Acute Lymphoblastic Leukemia in a Child with Trisomy 21 and Complex Congenital Heart Disease with Mechanical Prosthetic Valve

    Directory of Open Access Journals (Sweden)

    Saima Alvi

    2012-01-01

    Full Text Available A 10-year-old girl with trisomy 21 and complex congenital heart disease presented with acute lymphoblastic leukemia. Her chemotherapy required modifications due to poor baseline cardiac status and a mechanical prosthetic heart valve that was dependent on anticoagulation. We describe our management including the use of low-molecular-weight heparin as anticoagulation for a mechanical heart valve, the safe delivery of intrathecal chemotherapy included bridging with unfractionated heparin, and the use of fluoroscopic guidance to minimize the risk of bleeding. Adjustments were made to avoid anthracyclines. The child tolerated therapy well without complications and remains relapse free five years after diagnosis.

  16. The additional value of three-dimensional transesophageal echocardiography in complex aortic prosthetic heart valve endocarditis.

    Science.gov (United States)

    Tanis, Wilco; Teske, Arco J; van Herwerden, Lex A; Chamuleau, Steven; Meijboom, Folkert; Budde, Ricardo P J; Cramer, Maarten-Jan

    2015-01-01

    Two-dimensional transthoracic and transesophageal echocardiography (2DTTE and 2DTEE) may fail to detect signs of prosthetic heart valve (PHV) endocarditis due to acoustic shadowing. Three-dimensional (3D) TEE may have additional value; however, data are scarce. This study was performed to investigate the additional value of 3DTEE for the detection of aortic PHV endocarditis and the extent of the disease process. Retrospective analysis of complex aortic PHV endocarditis cases that underwent 2DTTE, 2DTEE, and 3DTEE before surgery. Echocardiograms were individually assessed by 2 cardiologists blinded for the outcome. Surgical and pathological inspection served as the reference standard for vegetations and peri-annular extensions (abscesses/mycotic aneurysms). To determine if the proximal coronary arteries were involved in the inflammatory process as well, computed tomography angiography findings were added to reference standard. Fifteen aortic PHV endocarditis cases were identified. According to the reference standard, all 15 cases had peri-annular extensions, 13 of which had a close relationship with the proximal right and/or left coronary artery. In 6 of 15 patients, a vegetation was present. Combined 2DTTE/TEE missed 1/6 vegetations and 1/15 peri-annular extensions. After addition of 3DTEE, all vegetations (6/6) and peri-annular extensions (15/15) were detected, without adding false positives. Compared to 2DTEE, in 3/15 cases, 3DTEE resulted in better delineation of the anatomical relationship of the proximal coronary arteries to the peri-annular extensions. As a result, 3DTEE had an additional value in 5/15 cases. In complex aortic, PHV endocarditis 3DTEE may have additional value compared to 2D echocardiography. © 2014, Wiley Periodicals, Inc.

  17. Effect of metoprolol on heart rate variability in symptomatic patients with mitral valve prolapse.

    Science.gov (United States)

    Taçoy, Gülten; Balcioğlu, Akif Serhat; Arslan, Uğur; Durakoğlugil, Emre; Erdem, Güliz; Ozdemir, Murat; Cengel, Atiye

    2007-06-01

    Metoprolol is widely used to eliminate symptoms in patients with mitral valve prolapse (MVP), a condition associated with enhanced sympathetic tone. In this study, effects of metoprolol on heart rate variability (HRV) indices were investigated in symptomatic patients with MVP. Thirty-nine symptomatic patients with MVP (26 women, mean age 26 +/- 7 years) and 16 age- and gender-matched controls were studied. After a baseline 24-hour Holter evaluation in all subjects, patients with MVP were started on metoprolol succinate therapy at a dose of 25 to 100 mg/d, and Holter analysis was repeated at the end of 3 months of metoprolol therapy. At the basal evaluation, all time-domain HRV indices with the exception of proportion of adjacent RR intervals differing by >50 ms in the 24-hour recording were significantly lower in patients with MVP than controls (SD of all normal-to-normal [NN] intervals, p = 0.013; SD of average NN intervals calculated during 5-minute periods of the entire recording, p = 0.03; triangular index, p = 0.025; and square root of mean squared differences in successive NN intervals, p = 0.026). After metoprolol treatment, all HRV indices significantly improved compared with baseline (SD of all NN intervals, p = 0.028; SD of average NN intervals calculated during 5-minute periods of the entire recording, p = 0.043; triangular index, p = 0.004; square root of the mean squared differences in successive NN intervals, p = 0.021; and proportion of adjacent RR intervals differing by >50 ms in the 24-hour recording, p = 0.014), and HRV indices after metoprolol treatment were similar to those of the control group (p >0.05). In conclusion, metoprolol significantly improved impaired HRV parameters in symptomatic patients with MVP.

  18. Cytotoxicity of PVPAC-treated bovine pericardium: a potential replacement for glutaraldehyde in biological heart valves.

    Science.gov (United States)

    Barros, Janaina Aline Galvão; Filippin-Monteiro, Fabiola Branco; de Oliveira, Edson Mendes; Campa, Ana; Catalani, Luiz Henrique; Pitombo, Ronaldo de Nogueira Moraes; Polakiewicz, Bronislaw

    2014-04-01

    Acellular biological tissues, including bovine pericardium (BP), have been proposed as biomaterial for tissue engineering. BP is usually modified chemically to improve mechanical and biological properties using glutaraldehyde, the standard reagent for preservation of fresh bioprosthetic materials. Glutaraldehyde-fixed BP (Glut-BP), the most widely used material in heart valve manufacture, has been associated with calcification in vivo. In an attempt to reduce this issue and maintain its biocompatibility, this study assesses the physical properties and cytotoxicity of lyophilized BP treated with poly (vinylpyrrolidone-co-acrolein) (PVPAC-BP), a novel copolymer, as a substitute for glutaraldehyde. For that, PVPAC-BP surface ultrastructure, elastic function, water uptake and tissue calcification were evaluated. For the analysis of biocompatibility, fibroblasts (3T3-L1) and endothelial cells (HUVEC) were cultured on PVPAC-BP, Untreated-BP and Glut-BP. Nitric oxide (NO) release assay, fluorescence and SEM images of endothelial cells adhered on scaffolds were also performed. As results, the data show some advantages of PVPAC-BP over the Glut-BP. The PVPAC-BP maintains partially the original ultrastructure and elastic properties, improves scaffold hydration, and presents less calcium phosphate deposits. The cells demonstrated strong attachment, high proliferation rate, and formation of a monolayer on PVPAC-BP. Attached cells were also able to release NO de-monstrating regular metabolism. In conclusion, PVPAC may be considered as a promising alternative to BP treatment improving the efficiency of cell attachment and proliferation and also avoid immunogenicity. Copyright © 2013 Wiley Periodicals, Inc.

  19. In situ heart valve tissue engineering using a bioresorbable elastomeric implant - From material design to 12 months follow-up in sheep.

    Science.gov (United States)

    Kluin, Jolanda; Talacua, Hanna; Smits, Anthal I P M; Emmert, Maximilian Y; Brugmans, Marieke C P; Fioretta, Emanuela S; Dijkman, Petra E; Söntjens, Serge H M; Duijvelshoff, Renée; Dekker, Sylvia; Janssen-van den Broek, Marloes W J T; Lintas, Valentina; Vink, Aryan; Hoerstrup, Simon P; Janssen, Henk M; Dankers, Patricia Y W; Baaijens, Frank P T; Bouten, Carlijn V C

    2017-05-01

    The creation of a living heart valve is a much-wanted alternative for current valve prostheses that suffer from limited durability and thromboembolic complications. Current strategies to create such valves, however, require the use of cells for in vitro culture, or decellularized human- or animal-derived donor tissue for in situ engineering. Here, we propose and demonstrate proof-of-concept of in situ heart valve tissue engineering using a synthetic approach, in which a cell-free, slow degrading elastomeric valvular implant is populated by endogenous cells to form new valvular tissue inside the heart. We designed a fibrous valvular scaffold, fabricated from a novel supramolecular elastomer, that enables endogenous cells to enter and produce matrix. Orthotopic implantations as pulmonary valve in sheep demonstrated sustained functionality up to 12 months, while the implant was gradually replaced by a layered collagen and elastic matrix in pace with cell-driven polymer resorption. Our results offer new perspectives for endogenous heart valve replacement starting from a readily-available synthetic graft that is compatible with surgical and transcatheter implantation procedures. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  20. A new approach to heart valve tissue engineering: mimicking the heart ventricle with a ventricular assist device in a novel bioreactor.

    Science.gov (United States)

    Kaasi, Andreas; Cestari, Idágene A; Stolf, Noedir A G; Leirner, Adolfo A; Hassager, Ole; Cestari, Ismar N

    2011-04-01

    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 the cell-scaffold constructs to a wider array of mechanical forces. The pump of the VAD has two chambers: a blood and a pneumatic chamber, separated by an elastic membrane. Pulsatile air-pressure is generated by a piston-type actuator and delivered to the pneumatic chamber, ejecting the fluid in the blood 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, variable throttle and reservoir, connected by silicone tubings. The reservoir sat on an elevated platform, allowing adjustment of ventricular preload between 0 and 11 mmHg. To allow for sterile gaseous exchange between the circuit interior and exterior, a 0.2 µm filter was placed at the reservoir. Pressure 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 presented here represents a new perspective to conventional biomimetic approaches in TE, with potential advantages.

  1. The preventive role of the posterior pericardial window in the development of late cardiac tamponade following heart valve surgery.

    Science.gov (United States)

    Uzun, Kemal; Günaydın, Zeki Yuksel; Tataroǧlu, Cenk; Bektaş, Osman

    2016-05-01

    It is reported that creating a window from the posterior pericardium into the left pleural cavity during coronary bypass surgeries reduces postoperative late cardiac tamponades. Although late tamponades are more common after heart valve surgeries, this procedure is not generally performed. The present study investigated whether creating a window has a preventive effect on the formation of late cardiac tamponade after heart valve surgeries. The study was conducted on all patients (n = 262) in whom one or more valves were replaced and who fulfilled the study criteria between January 2010 and October 2014 in one centre. We began to create a posterior pericardial window in all valvular patients from March 2012. One hundred and thirty-five patients operated on before this date (Non-Window Group) and 127 patients after this date (Window Group) were compared for the development of late cardiac tamponade. There were no differences between the groups in terms of preoperative and intraoperative characteristics. Late pericardial tamponade was not observed in any patients from the Window Group, whereas it occurred in 7 (5.2%) patients from the Non-Window Group (P = 0.015). Three patients died in total; all 3 were from the Non-Window Group. One of the mortalities was associated with tamponade. Creating a pericardial window may reduce late cardiac tamponade events/episodes, which may be a fatal complication in valve patients. We recommend performing this procedure by allocating some time during the surgical procedure in order to avoid tamponade. © The Author 2016. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  2. Magnesium Presence Prevents Removal of Antigenic Nuclear-Associated Proteins from Bovine Pericardium for Heart Valve Engineering.

    Science.gov (United States)

    Dalgliesh, Ailsa J; Liu, Zhi Zhao; Griffiths, Leigh G

    2017-03-10

    Current heart valve prostheses are associated with significant complications, including aggressive immune response, limited valve life expectancy, and inability to grow in juvenile patients. Animal derived "tissue" valves undergo glutaraldehyde fixation to mask tissue antigenicity; however, chronic immunological responses and associated calcification still commonly occur. A heart valve formed from an unfixed bovine pericardium (BP) extracellular matrix (ECM) scaffold, in which antigenic burden has been eliminated or significantly reduced, has potential to overcome deficiencies of current bioprostheses. Decellularization and antigen removal methods frequently use sequential solutions extrapolated from analytical chemistry approaches to promote solubility and removal of tissue components from resultant ECM scaffolds. However, the extent to which such prefractionation strategies may inhibit removal of antigenic tissue components has not been explored. We hypothesize that presence of magnesium in prefractionation steps causes DNA precipitation and reduces removal of nuclear-associated antigenic proteins. Keeping all variables consistent bar the addition or absence of magnesium (2 mM magnesium chloride hexahydrate), residual BP ECM scaffold antigenicity and removed antigenicity were assessed, along with residual and removed DNA content, ECM morphology, scaffold composition, and recellularization potential. Furthermore, we used proteomic methods to determine the mechanism by which magnesium presence or absence affects scaffold residual antigenicity. This study demonstrates that absence of magnesium from antigen removal solutions enhances solubility and subsequent removal of antigenic nuclear-associated proteins from BP. We therefore conclude that the primary mechanism of action for magnesium removal during antigen removal processes is avoidance of DNA precipitation, facilitating solubilization and removal of nuclear-associated antigenic proteins. Future studies are

  3. Emergency use of cardiopulmonary bypass in complicated transcatheter aortic valve replacement: importance of a heart team approach.

    Science.gov (United States)

    Roselli, Eric E; Idrees, Jay; Mick, Stephanie; Kapadia, Samir; Tuzcu, Murat; Svensson, Lars G; Lytle, Bruce W

    2014-10-01

    Transcatheter aortic valve replacement (TAVR) expands options for high-risk patients with aortic stenosis but is complex with life-threatening complications. We describe indications for use of salvage cardiopulmonary bypass (CPB) and assess outcomes. From 2006 to 2011, 303 patients underwent TAVR, and 12 (4%) required emergency CPB. Approach was transapical (9) and transfemoral (3). Mean age was 82±9 years, median Society of Thoracic Surgeons score was 11 and mean gradient was 46±9 mm Hg. Access for CPB was femoral under fluoroscopy. Principal indication for CPB was hemodynamic instability with or without ischemic changes. These resulted from aortic insufficiency (n=5), valve embolization (n=3), coronary malperfusion (n=2), bleeding requiring pericardiocentesis (n=1), and bleeding from ventricular apex (n=1). Additional procedures included valve-in-valve TAVR (n=5), surgical valve replacement (n=3), and coronary intervention (n=2). Additional circulatory support was used in 7 cases: intra-aortic balloon pump (5) and extracorporeal membrane oxygenation (3). There were 2 hospital deaths. Mean postoperative gradient was 12±9 mm Hg, and median stay was 16 days. There were no myocardial infarctions or renal failure. One patient had stroke with arm weakness, 2 required tracheostomy, and 2 underwent reoperations for bleeding. Median follow-up was 19 months, and there were 5 late deaths. Complications during TAVR can be life threatening and may necessitate additional procedures. Expeditious use of CPB support provided by a multidisciplinary heart team optimizes rescue after myocardial collapse. Copyright © 2014 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

  4. 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.

  5. 风湿性心脏病手术3个瓣膜同时置换的临床经验%Experience of triple-valve replacement in rheumatic heart valve disease

    Institute of Scientific and Technical Information of China (English)

    张国报; 乔刚; 赵小娟; 权晓强; 赵健; 程兆云

    2012-01-01

    Objective:To explore the triple-valve replacement experience in rheumatic heart valve disease. Methods: We reviewed our experience in A patients who underwent combined mitral and aortic valve replacement with tricuspid valve replacement between 2007 and 2011. Results:We found tricuspid annular dilatation and leaflet thickening resulting in tricuspid regurgitation in four patients, tricuspid commissural fusion leading to tricuspid stenosis in two patients. One patient received bioprosthetic valves replacement procedures in aortic and mitral position with tricuspid position. The other three patients received mechanical valves replacement procedures in aortic and mitral position, and bioprosthetic valve in tricuspid position. One patient died after operation due to low cardiac output syndrome. The mean follow-up was 30 months (range, 12 to 49 months). Post-operative heart function NYHA classifi-cation:two cases in class I, one case in class Ⅱ. Conclusion;We recommend the use of a bioprosthetic valve in tricuspid position if tricuspid valve should be replaced. Even if mechanical valves are implanted in the left side of the heart, a bioprosthetic valve may be a better choice at the tricuspid position.%目的:探讨风湿性心脏病手术中3个瓣膜同时置换的经验.方法:对4例同时置换二尖瓣、主动脉瓣和三尖瓣的病人资料进行分析.结果:术中发现4例病人均有三尖瓣环扩大和瓣叶增厚导致关闭不全,2例病人伴有交界融合导致瓣膜狭窄.1例病人接受了二尖瓣位、主动脉瓣位以及三尖瓣位生物瓣置换.另3例病人接受了二尖瓣位和主动脉瓣位机械瓣置换,以及三尖瓣位生物瓣置换.1例病人死于术后低心排.其他病人平均随访30个月(12~49个月),术后心功能I级2例,Ⅱ级1例.结论:如果三尖瓣需要置换时应使用生物瓣.尽管左侧心脏瓣膜应用机械瓣,三尖瓣位应用生物瓣仍是较好的选择.

  6. 猪去细胞心脏瓣膜的免疫原性%Immunogenicity of decellularized porcine heart valve

    Institute of Scientific and Technical Information of China (English)

    李秋泽; 徐志云; 黄盛东; 张宝仁; 杨立信; 刘晓红; 袁扬; 龚德军

    2009-01-01

    inflammatory response in humans during clinical application of decellularized porcine heart valve (synergraft valves). An early inflammatory reaction severely weakens matrix structure of valve wall, leading to structural rupture and decay of grafts. From Synergraft's event, the decellularized porcine heart valves still had immunogenicity, especially for pediatric patients. The mechanisms by which the ECM triggers this immune process need to be further evaluated. OBJECTIVE: To find the difference of gene sequence between human and porcine ECM and to identify the ECM immunogenicity based on bioinformatics. DESIGN, TIME AND SETTING: A contrast study between human and porcine ECM based on type IV collagen was performed at the Laboratory of Cardiothoracic Surgery, Changhai Hospital, the Second Military Medical University of Chinese PLA from June 2008 to February May.MATERIALS: The fresh porcine heart valves were obtained from Shanghai Wufengshangshi Slaughter House. Decellularized porcine aortic valves, hybridoma cells, and monoclonal antibodies were provided by our laboratory. METHODS: Similar region and conservative site of gene sequence among human, porcine, and rat were compared so as to look for common similar region, site, and sequence difference and investigate the segment which caused common and different gene sequence. Type IV collagen monoclonal antibody was used to evaluate the persistence of ECM of decellularized porcine heart valve following immunohistochemical staining. MAIN OUTCOME MEASURES: Type IV collagen gene sequence; efficacy of self-made antibody using immunohistochemistry; effect of self-made antibody on type IV collage of decellularized porcine heart valve. RESULTS: The differential gene serial in type IV collagen protein was found out by bioinformatics method. Monoclonal antibodies were successfully produced by human-mouse hybridoma technique. Residual porcine ECM was observed on decellularized porcine heart valve. CONCLUSION: Residual porcine ECM was

  7. Mitral valve surgery - open

    Science.gov (United States)

    ... Saunders; 2012:chap 61. Otto CM, Bonow RO. Valvular heart disease. In: Mann DL, Zipes DP, Libby P, Bonow ... Editorial team. Related MedlinePlus Health Topics Heart Surgery Heart Valve Diseases Mitral Valve Prolapse Browse the Encyclopedia A.D. ...

  8. 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.

  9. 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

  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. 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.

  12. Outcomes and Prognostic Factors for Adult Patients With Congenital Heart Disease Undergoing Primary or Reoperative Systemic Atrioventricular Valve Surgery.

    Science.gov (United States)

    Stephens, Elizabeth H; Han, Jiho; Ginns, Jonathan; Rosenbaum, Marlon; Chai, Paul; Bacha, Emile; Kalfa, David

    2017-05-01

    Adults with congenital heart disease (ACHD) undergoing systemic atrioventricular valve (SAVV) surgery are a complex, understudied population. We assessed midterm outcomes and prognostic factors in ACHD undergoing SAVV surgery. We performed retrospective evaluation of ACHD undergoing SAVV surgery from January 2005 to February 2016: 14 (33%) patients with congenital mitral valve stenosis/regurgitation, 15 (35%) with atrioventricular septal defect (AVSD), and 14 (33%) with congenitally corrected transposition of the great arteries (ccTGA) with systemic tricuspid valve regurgitation. Adverse events were defined as mortality, reoperation on SAVV, and late more-than-moderate (> moderate) SAVV regurgitation. Statistical analysis was performed using Fisher's exact test and one-way analysis of variance as well as univariate and multivariate risk factor analysis. Fifteen (35%) patients had preoperative systemic ventricular dysfunction, including 13 patients with ccTGA (93%, P moderate SAVV regurgitation, and SAVV reoperation rates were 5% (n = 2), 2% (n = 1), 9% (n = 3), and 7% (n = 3), respectively. On multivariate analysis, predischarge SAVV regurgitation grade was the only significant predictor of adverse events (odds ratio = 8.2, 95% confidence interval: 1.1-63.8, P = .045). Overall outcomes in this challenging population are good. The single factor associated with adverse events was predischarge SAVV regurgitation grade.

  13. Cardioprotection of Electroacupuncture for Enhanced Recovery after Surgery on Patients Undergoing Heart Valve Replacement with Cardiopulmonary Bypass: A Randomized Control Clinical Trial

    Directory of Open Access Journals (Sweden)

    Fangxiang Zhang

    2017-01-01

    Full Text Available We attempted to investigate cardioprotection of electroacupuncture (EA for enhanced recovery after surgery on patients undergoing heart valve replacement with cardiopulmonary bypass. Forty-four patients with acquired heart valve replacement were randomly allocated to the EA group or the control group. Patients in the EA group received EA stimulus at bilateral Neiguan (PC6, Ximen (PC4, Shenting (GV24, and Baihui (GV20 acupoints twenty minutes before anesthesia induction to the end of surgery. The primary end point was cardioprotection effect of electroacupuncture postoperatively and the secondary endpoints were quality of recovery and cognitive functioning postoperatively. The present study demonstrated that electroacupuncture reduced the occurrence of complications and played a role of cardioprotective effect on patients after heart valve replacement surgery with cardiopulmonary bypass, and it benefits patients more comfortable and contributes to recovery after surgery. This trial is registered with ChiCTR-IOC-16009123.

  14. Correctness of multi-detector-row computed tomography for diagnosing mechanical prosthetic heart valve disorders using operative findings as a gold standard

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, I.Chen [Taichung Veterans General Hospital, Department of Radiology, Taichung (China); Institute of Clinical Medicine and Faculty of Medicine, National Yang-Ming University, Taipei (China); Lin, Yung-Kai; Chang, Yen; Wang, Chung-Chi; Hsieh, Shih-Rong; Wei, Hao-Ji; Tsai, Hung-Wen [Taichung Veterans General Hospital, Section of Cardiovascular Surgery, Cardiovascular Center, Taichung (China); Fu, Yun-Ching; Jan, Sheng-Ling [Institute of Clinical Medicine and Faculty of Medicine, National Yang-Ming University, Taipei (China); Taichung Veterans General Hospital, Section of Pediatric Cardiology, Department of Pediatrics, Taichung (China); Wang, Kuo-Yang [Taichung Veterans General Hospital, Section of General Cardiology, Cardiovascular Center, Taichung (China); Chung-Shan Medical University, Department of Medicine, Taichung (China); Chen, Min-Chi; Chen, Clayton Chi-Chang [Taichung Veterans General Hospital, Department of Radiology, Taichung (China); Central Taiwan University of Science and Technology, Department of Radiological Technology, Taichung (China)

    2009-04-15

    The purpose was to compare the findings of multi-detector computed tomography (MDCT) in prosthetic valve disorders using the operative findings as a gold standard. In a 3-year period, we prospectively enrolled 25 patients with 31 prosthetic heart valves. MDCT and transthoracic echocardiography (TTE) were done to evaluate pannus formation, prosthetic valve dysfunction, suture loosening (paravalvular leak) and pseudoaneurysm formation. Patients indicated for surgery received an operation within 1 week. The MDCT findings were compared with the operative findings. One patient with a Bjoerk-Shiley valve could not be evaluated by MDCT due to a severe beam-hardening artifact; thus, the exclusion rate for MDCT was 3.2% (1/31). Prosthetic valve disorders were suspected in 12 patients by either MDCT or TTE. Six patients received an operation that included three redo aortic valve replacements, two redo mitral replacements and one Amplatzer ductal occluder occlusion of a mitral paravalvular leak. The concordance of MDCT for diagnosing and localizing prosthetic valve disorders and the surgical findings was 100%. Except for images impaired by severe beam-hardening artifacts, MDCT provides excellent delineation of prosthetic valve disorders. (orig.)

  15. Two-component laser Doppler anemometer for measurement of velocity and turbulent shear stress near prosthetic heart valves.

    Science.gov (United States)

    Woo, Y R; Yoganathan, A P

    1985-01-01

    The velocity and turbulent shear stress measured in the immediate vicinity of prosthetic heart valves play a vital role in the design and evaluation of these devices. In the past hot wire/film and one-component laser Doppler anemometer (LDA) systems were used extensively to obtain these measurements. Hot wire/film anemometers, however, have some serious disadvantages, including the inability to measure the direction of the flow, the disturbance of the flow field caused by the probe, and the need for frequent calibration. One-component LDA systems do not have these problems, but they cannot measure turbulent shear stresses directly. Since these measurements are essential and are not available in the open literature, a two-component LDA system for measuring velocity and turbulent shear stress fields under pulsatile flow conditions was assembled under an FDA contract. The experimental methods used to create an in vitro data base of velocity and turbulent shear stress fields in the immediate vicinity of prosthetic heart valves of various designs in current clinical use are also discussed.

  16. The fate of small-size pericardial heart valve prostheses in an older patient population.

    Science.gov (United States)

    De Paulis, Ruggero; D'Aleo, Salvatore; Bellisario, Alessandro; Salica, Andrea; Weltert, Luca P; Scaffa, Raffaele; Wolf, Lorenzo Guerrieri; Maselli, Daniele; Di Mauro, Michele

    2017-01-01

    Structural valve deterioration (SVD) is the Achilles' heel of bioprostheses. Its correlation with younger age is well known. In recent years we exclusively reserved use of small-size Mitroflow valve prostheses (LivaNova, London, United Kingdom) to an older patient population with small aortic annuli. This study aimed to assess the incidence of SVD and its effect on patient survival and need for reoperation. Two hundred five patients (aged 75.9 ± 5.3 years; range, 62-92 years) underwent aortic valve replacement with a 19-mm or 21-mm Mitroflow valve prosthesis between 2005 and 2011. The great majority was female (n = 170; 83%). In half of patients it was an isolated procedure. All valve prostheses were implanted in a supra-annular position using pledgeted sutures. A 19-mm valve was implanted in 93 patients (45.3%), whereas in 112 patients (54.6%) a 21-mm valve was used. Twenty-three patients (11.2%) were diagnosed with early SVD by echocardiography. Average time from surgery to diagnosis of SVD was 64.3 ± 26.8 months. Ten patients needed a reoperation for SVD. Average time from surgery to a second operation was 45.7 ± 35.7 months. Overall survival was 64.5% and 42.3% at 5 and 9 years, respectively. Cumulative freedom from SVD at 5 and 9 years was 94.8% ± 1.6% and 77.4% ± 5.4%, respectively. In 4 patients death was linked to the presence of SVD. There were no differences in mortality, reoperation, or SVD between the 2 Mitroflow valve sizes. Small-size Mitroflow pericardial valve prostheses have shown a worrisome incidence of SVD even in patients aged >70 years. Based on this experience we have discontinued their use. Copyright © 2016 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

  17. A phospholipid-modified polystyrene-polyisobutylene-polystyrene (SIBS) triblock polymer for enhanced hemocompatibility and potential use in artificial heart valves.

    Science.gov (United States)

    Duraiswamy, Nandini; Choksi, Tejas D; Pinchuk, Leonard; Schoephoerster, Richard T

    2009-01-01

    Poly(styrene-block-isobutylene-block-styrene) ('SIBS') is selected for a novel tri-leaflet heart valve due to its high resistance to oxidation, hydrolysis, and enzyme attack. SIBS is modified using six different phospholipids and its mechanical properties characterized by tensile stress, peel strength, shear strength, contact angle, and surface energy, and then for hemocompatibility by studying the adhesion of fluorescently labeled platelets in a parallel plate chamber under physiological flow conditions. Phospholipid modification decreases SIBS tensile stress (at 45% strain) by 30% and reduces platelet adhesion by a factor of 10, thereby improving its hemocompatibility and its potential use as a synthetic heart valve.

  18. 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

  19. 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.

  20. Senile calcified heart valve disease and coronary heart disease (CHD) analysis of the related factors%老年性钙化性心脏瓣膜病与冠心病的相关因素分析

    Institute of Scientific and Technical Information of China (English)

    杨菊月

    2015-01-01

    目的:观察和分析老年性钙化性心脏瓣膜病和冠心病之间的相关因素。方法将我院自2014年1月至2015年1月间收治的老年性心脏瓣膜病患者患者120例作为研究对象,其中钙化性心脏瓣膜病患者和非钙化性心脏瓣膜病患者各60例,对两组患者的临床资料进行回顾性分析,研究两组患者各项生理指标以及冠心病检出情况。结果老年性心脏瓣膜病患者中钙化组检出冠心病的概率为91.67%明显高于非钙化组56.67%,组间比较差异显著(P<0.05),具有统计学意义。结论老年性钙化性心脏瓣膜病和冠心病之间存在密切的关系,加强对钙化性心脏瓣膜病的诊断有利于冠心病的临床预测。%objective: to observe and analyze the senile calcified heart valve disease and coronary heart disease (cHd) between the related factors. Methods:from January 2014 to January 2015 were 120 cases of patients with senile heart valve disease as the research object, the calciifed heart valve disease and non calciifed heart valve disease all 60 cases, the clinical data of two groups of patients were retrospectively analyzed, and research the physiological indexes in both groups, and detection of coronary heart disease. Results:senile heart valve calciifcation group and the probability of detection of coronary artery disease in patients for 91.67% to 56.67%, significantly higher than the calcification group is significant difference between groups (P<0.05), with statistical signiifcance. Conclusion:the senile calciifed heart valve disease and coronary heart disease, there is a close relationship between strengthen of calciifed heart valve disease diagnosis is helpful to clinical prediction of coronary heart disease (cHd).

  1. 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

    OBJECTIVE: To elucidate the association between treatment with ergot-derived dopamine agonists (EDDA) and valvular abnormalities amongst patients with idiopathic Parkinson's disease (IPD) and secondly, to analyse the yield of clinical screening for valvular heart disease. DESIGN: A cross....... 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...

  2. Preseeding of human vascular cells in decellularized bovine pericardium scaffold for tissue-engineered heart valve : An in vitro and in vivo feasibility study

    NARCIS (Netherlands)

    Yang, Min; Chen, Chang-Zhi; Shu, Yu-Sheng; Shi, Wei-Ping; Cheng, Shao-Fei; Gu, Y. John

    Human vascular cells from saphenous veins have been used for cell seeding on the synthetic scaffolds for constructing tissue-engineered heart valve (TEHV). However, little is known about the seeding of human vascular cells on bovine pericardium, a potential natural scaffold for TEHV. This study was

  3. 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

  4. Preseeding of human vascular cells in decellularized bovine pericardium scaffold for tissue-engineered heart valve : An in vitro and in vivo feasibility study

    NARCIS (Netherlands)

    Yang, Min; Chen, Chang-Zhi; Shu, Yu-Sheng; Shi, Wei-Ping; Cheng, Shao-Fei; Gu, Y. John

    2012-01-01

    Human vascular cells from saphenous veins have been used for cell seeding on the synthetic scaffolds for constructing tissue-engineered heart valve (TEHV). However, little is known about the seeding of human vascular cells on bovine pericardium, a potential natural scaffold for TEHV. This study was

  5. Flow visualization of a monoleaflet and bileaflet mechanical heart valve in a pneumatic ventricular assist device using a PIV system.

    Science.gov (United States)

    Lee, Hwansung; Tatsumi, Eisuke; Taenaka, Yoshiyuki

    2010-01-01

    Our group is developing a new type of pulsatile pneumatic ventricular assist device (PVAD) that uses the Medtronic Hall tilting disc valve (M-H valve). Although tilting disc valves have good washout effect inside the blood pump, they are no longer in common clinical use and may be difficult to obtain in the future. To investigate the stability of the Sorin Bicarbon valve (S-B valve) in our PVAD, we constructed a model pump made of an acrylic resin with the same configuration as our PVAD and attempted to compare the flow visualization upstream and downstream of the outlet position valve between the M-H valve and the S-B valve using a particle image velocimetry (PIV) method. The outlet S-B valve had faster closure than the M-H valve. The maximum flow velocity was greater than with the M-H valve. The maximum Reynolds shear stress (RSS) of the M-H valve reached 150 N/m(2) and that of the S-B valve reached 300 N/m(2) upstream during the end-systolic and early-diastolic phases. In both valves, the maximum RSS upstream of the valve was higher than downstream of the valve because of the regurgitation flow during valve closure. In addition, the maximum viscous shear stress reached above 2 N/m(2), which occupied only about 1%-1.5% of the maximum RSS.

  6. Which valve is which?

    Directory of Open Access Journals (Sweden)

    Pravin Saxena

    2015-01-01

    Full Text Available A 25-year-old man presented with a history of breathlessness for the past 2 years. He had a history of operation for Tetralogy of Fallot at the age of 5 years and history suggestive of Rheumatic fever at the age of 7 years. On echocardiographic examination, all his heart valves were severely regurgitating. Morphologically, all the valves were irreparable. The ejection fraction was 35%. He underwent quadruple valve replacement. The aortic and mitral valves were replaced by metallic valve and the tricuspid and pulmonary by tissue valve.

  7. Legionella cardiaca sp. nov., isolated from a case of native valve endocarditis in a human heart.

    Science.gov (United States)

    Pearce, Meghan M; Theodoropoulos, Nicole; Mandel, Mark J; Brown, Ellen; Reed, Kurt D; Cianciotto, Nicholas P

    2012-12-01

    A Gram-negative, rod-shaped bacterium, designated H63(T), was isolated from aortic valve tissue of a patient with native valve endocarditis. 16S rRNA gene sequencing revealed that H63(T) belongs to the genus Legionella, with its closest neighbours being the type strains of Legionella brunensis (98.8% similarity), L. londiniensis (97.0%), L. jordanis (96.8%), L. erythra (96.2%), L. dresdenensis (96.0%) and L. rubrilucens, L. feeleii, L. pneumophila and L. birminghamensis (95.7%). DNA-DNA hybridization studies yielded values of cardiaca sp. nov. is proposed. The type strain is H63(T) ( = ATCC BAA-2315(T)  = DSM 25049(T)  = JCM 17854(T)).

  8. 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

  9. 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

  10. Heart valve replacement in the elderly patient%老年心脏瓣膜置换术

    Institute of Scientific and Technical Information of China (English)

    郑知非; 李颖则; 龚宝生; 任书南; 邱兆昆

    2000-01-01

    Objective To review over the heart valve replacement in the elderly patients, including those oper-ated secondarily and tertiarily. Methods From August 1994 to August 1998, 57 consecutive elderly cardiac patients(age 60 to 75 years, mean 65.8 years) were operated in our hospital. There were 38 mitral valve replacement, 7 aorticvalve replacement and 12 multiple valvular replacement, including 13 (22.8 % ) re-stenotic mitral valve after left-routeclosed mitral commissurotomy and 6 (10.5%) re-re-stenotic mitral valve after reoperative dual-route closed mitral com-missurotomy. Results Four patients (7.01%) died, including 1 re-stenotic and 2 re-re-stenotic patients. The follow-up period was 3 months to 4 years. There were 4 late deaths, 3(5.8%) related to heart failure and myocardial infarc-tion. Valve replacement related complications were thromboembolism in three (5.8%) cardiac failure, in two (3.9%)infective endocarditis and myocardial infarction in one (1.9%) each. 95.7% of the survived patients were in NYHAfunction grade 1~2. Conclusions Valvular replacement surgery in the elderly can be performed safely and effectivelywith improved myocardial protection, intraoperative strategies and postoperative care. And for those re-and re-re-stenotic patients, the details of pulmonary and renal functions should be carefully evaluated preoperatively. (ShanghaiMed J, 2000,23:603-605)%目的 观察首次和多次心脏手术的老年心脏瓣膜病施行瓣膜置换术的疗效。方法 从1994年8月到1998年8月,共对57例老年患者(60~75岁)施行瓣膜置换术,包括13例(22.8%)二尖瓣行"闭式分离术"后再狭窄患者和6例(10.5%)二尖瓣再狭窄行"双径闭式分离术"后再-再狭窄患者。结果 手术死亡4例(7.01%),其中有1例再狭窄和2例再-再狭窄患者。随访3个月到4年,晚期死亡4例,3例(5.8%)死于顽固性心力衰竭和急性心梗;瓣膜相关的并发症有:3例(5.8

  11. Bioprinting a cardiac valve.

    Science.gov (United States)

    Jana, Soumen; Lerman, Amir

    2015-12-01

    Heart valve tissue engineering could be a possible solution for the limitations of mechanical and biological prostheses, which are commonly used for heart valve replacement. In tissue engineering, cells are seeded into a 3-dimensional platform, termed the scaffold, to make the engineered tissue construct. However, mimicking the mechanical and spatial heterogeneity of a heart valve structure in a fabricated scaffold with uniform cell distribution is daunting when approached conventionally. Bioprinting is an emerging technique that can produce biological products containing matrix and cells, together or separately with morphological, structural and mechanical diversity. This advance increases the possibility of fabricating the structure of a heart valve in vitro and using it as a functional tissue construct for implantation. This review describes the use of bioprinting technology in heart valve tissue engineering.

  12. 38例心脏瓣膜病合并冠心病的外科手术治疗效果分析%Effect of Surgical Treatment for 38 Cases of Heart Valve Disease With Coronary Heart Disease

    Institute of Scientific and Technical Information of China (English)

    陈惠锋

    2015-01-01

    目的:分析心脏瓣膜病合并冠心病的手术治疗效果。方法随机选取38例心脏瓣膜病合并冠心病患者行瓣膜置换或成形术,同期行冠状动脉旁路移植术的临床资料展开回顾性分析。结果38例心脏瓣膜病合并冠心病患者中3例患者因术后心脏破裂出血死亡,2例因多器官功能衰竭死亡,死亡率为13.15%;其余33例患者心功能均得到改善。结论对心脏瓣膜病合并冠心病患者实施瓣膜置换或成形术,并同期进行冠脉血运重建,可及时改善患者心功能,降低死亡率。%Objective To analyze the effect of surgical treatment of valvular heart disease with coronary artery disease. Methods The clinical data of 38 patients with valvular heart disease complicated with coronary heart disease underwent valve replacement or angioplasty, and the clinical data were analyzed retrospectively. Results In 38 patients with heart valve disease complicated with coronary heart disease, 3 patients died of cardiac rupture, 2 patients died of multiple organ failure, the mortality rate was 13.15%, and the other 33 patients were improved. Conclusion Valve replacement or angioplasty in patients with heart valve disease combined with coronary heart disease, and the same period of coronary revascularization, can improve the heart function, reduce mortality.

  13. Reliability and construct validity of the Instrument to Measure the Impact of Valve Heart Disease on the Patient's Daily Life.

    Science.gov (United States)

    Anjos, Daniela Brianne Martins Dos; Rodrigues, Roberta Cunha Matheus; Padilha, Kátia Melissa; Pedrosa, Rafaela Batista Dos Santos; Gallani, Maria Cecília Bueno Jayme

    2016-12-19

    evaluate the practicality, acceptability and the floor and ceiling effects, estimate the reliability and verify the convergent construct's validity with the instrument called the Heart Valve Disease Impact on daily life (IDCV) of the valve disease in patients with mitral and or aortic heart valve disease. data was obtained from 86 heart valve disease patients through 3 phases: a face to face interview for a socio-demographic and clinic characterization and then other two done through phone calls of the interviewed patients for application of the instrument (test and repeat test). as for the practicality and acceptability, the instrument was applied with an average time of 9,9 minutes and with 110% of responses, respectively. Ceiling and floor effects observed for all domains, especially floor effect. Reliability was tested using the test - repeating pattern to give evidence of temporal stability of the measurement. Significant negative correlations with moderate to strong magnitude were found between the score of the generic question about the impact of the disease and the scores of IDCV, which points to the validity of the instrument convergent construct. the instrument to measure the impact of valve heart disease on the patient's daily life showed evidence of reliability and validity when applied to patients with heart valve disease. avaliar a praticabilidade, aceitabilidade e os efeitos teto e chão, estimar a confiabilidade e verificar a validade de construto convergente do Instrumento para Mensuração do Impacto da Doença no Cotidiano do Valvopata em pacientes com valvopatia mitral e/ou aórtica. dados foram obtidos junto a 86 pacientes valvopatas por meio de três etapas: uma entrevista presencial para caracterização sociodemográfica e clínica e as duas outras realizadas por meio de contato telefônico para as aplicações do instrumento (Teste e teste de repetição). quanto à praticabilidade e aceitabilidade, o instrumento foi aplicado com tempo m

  14. Dynamic and fluid-structure interaction simulations of bioprosthetic heart valves using parametric design with T-splines and Fung-type material models

    Science.gov (United States)

    Hsu, Ming-Chen; Kamensky, David; Xu, Fei; Kiendl, Josef; Wang, Chenglong; Wu, Michael C. H.; Mineroff, Joshua; Reali, Alessandro; Bazilevs, Yuri; Sacks, Michael S.

    2015-06-01

    This paper builds on a recently developed immersogeometric fluid-structure interaction (FSI) methodology for bioprosthetic heart valve (BHV) modeling and simulation. It enhances the proposed framework in the areas of geometry design and constitutive modeling. With these enhancements, BHV FSI simulations may be performed with greater levels of automation, robustness and physical realism. In addition, the paper presents a comparison between FSI analysis and standalone structural dynamics simulation driven by prescribed transvalvular pressure, the latter being a more common modeling choice for this class of problems. The FSI computation achieved better physiological realism in predicting the valve leaflet deformation than its standalone structural dynamics counterpart.

  15. Limited dose warfarin throughout pregnancy in patients with mechanical heart valve prosthesis: a meta-analysis.

    Science.gov (United States)

    Hassouna, Ahmed; Allam, Hemat

    2014-06-01

    The continuation of warfarin throughout pregnancy in patients with a mechanical valve prosthesis is a valid anticoagulation regimen, provided that warfarin dose does not exceed 5 mg/day. Two decades after being introduced, the efficacy and safety of this regimen merit evaluation. We performed a systematic review for cases published between January 1991 and January 2013. We compiled our prospective data on 55 pregnancies and calculated pooled estimates (95% confidence interval) of adverse foetal and maternal outcomes. Events were expressed as proportions of total pregnancies, except embryopathy and maternal death, which were related to the number of live births and number of patients, respectively. There were 494 eligible pregnancies reported in 11 studies. The rate of embryopathy was 0.9% (0.4-2.4%) and most of the 13.4% (8.4-24.7%) foetal losses were due to the 12.8% (7.7-22.7%) rate of spontaneous abortion. No maternal mortality was encountered (0-1.3%) but 0.6% (0.3-2%) prosthetic valve thrombosis, 1.8% (1.1-3.6%) total thromboembolic events and 3.4% (2-5.1%) major maternal bleeding events were recorded. Foetal loss, spontaneous abortions and foetal embryopathy dropped to 8.1% (2.9-13.7%), 7.3% (3.1-11.8%) and 0.6% (0.1-2.1%) among the 344 pregnancies (69.6%) observed in the 6 prospective studies (54.5%). Prosthetic valve thrombosis (0.6%; 01-2%), total thromboembolic (2.3%; 1.2-4.6%) and major bleeding events (2.9%; 1.8-6%) remained comparable with overall results. Foetal embryopathy and prosthetic valve thrombosis were not robust on sensitivity analysis, regardless of the study design. A prospective subgroup of 96 patients (19.4%) received smaller warfarin dose, through targeting a lower international normalized ratio (INR) between 1.5 and 2.5. The associated rate of foetal loss (2.1%; 0.5-6.9%) was significantly lower than that observed in the remaining patients targeting a higher INR between 2.5 and 3.5 (16.1%; 13.1-34.4%). Adverse maternal outcomes were

  16. Fluid-Structure Interactions of the Mitral Valve and Left Heart: Comprehensive Strategies, Past, Present and Future

    Science.gov (United States)

    Einstein, Daniel R.; Del Pin, Facundo; Jiao, Xiangmin; Kuprat, Andrew P.; Carson, James P.; Kunzelman, Karyn S.; Cochran, Richard P.; Guccione, Julius M.; Ratcliffe, Mark B.

    2009-01-01

    SUMMARY The remodeling that occurs after a posterolateral myocardial infarction can alter mitral valve function by creating conformational abnormalities in the mitral annulus and in the posteromedial papillary muscle, leading to mitral regurgitation (MR). It is generally assumed that this remodeling is caused by a volume load and is mediated by an increase in diastolic wall stress. Thus, mitral regurgitation can be both the cause and effect of an abnormal cardiac stress environment. Computational modeling of ischemic MR and its surgical correction is attractive because it enables an examination of whether a given intervention addresses the correction of regurgitation (fluid-flow) at the cost of abnormal tissue stress. This is significant because the negative effects of an increased wall stress due to the intervention will only be evident over time. However, a meaningful fluid-structure interaction model of the left heart is not trivial; it requires a careful characterization of the in-vivo cardiac geometry, tissue parameterization though inverse analysis, a robust coupled solver that handles collapsing Lagrangian interfaces, automatic grid-generation algorithms that are capable of accurately discretizing the cardiac geometry, innovations in image analysis, competent and efficient constitutive models and an understanding of the spatial organization of tissue microstructure. In this manuscript, we profile our work toward a comprehensive fluid-structure interaction model of the left heart by reviewing our early work, presenting our current work and laying out our future work in four broad categories: data collection, geometry, fluid-structure interaction and validation. PMID:20454531

  17. [Post-operative management for 86 cases of heart valve replacement surgery patients undergoing transcutaneous electrical acupoint stimulation combined with general anesthesia].

    Science.gov (United States)

    Zhou, Wen-Xiong; Xu, Jian-Jun; Wu, Yao-Yao; Chi, Hao; Chen, Tong-Yu; Ge, Wen; Zhou, Jia

    2014-02-01

    To summarize post-operative management strategy for heart valve replacement surgery under transcutaneous electrical acupoint stimulation (TEAS) combined with general anesthesia. From July 2006 to June 2012, a total of 86 cases of open-heart surgery patients experiencing TEAS plus general anesthesia with cardiopulmonary bypass (heart valve replacement surgery without intubation) were recruited in the present summary. Post-operative managements in the Intensive Care Unit (ICU) were administrated with strict hemodynamic monitoring for volume infusion, routine administration of vasoactive drugs (including dopamine and nitroglycerin), oxygen inhalation, and analgesics and monitoring of central nervous system and renal function. All the 86 patients under TEAS + general anesthesia and cardiopulmonary bypass and without intubation experienced successful heart valve replacement surgery. The post-operative pulmonary infection was found in 8 cases (9.30%), the average stay duration in ICU was (28.6 +/- 6.2) hours, and the average draining volume of the interpleural space was (291 +/- 73)mL. The cardia insufficiency was found in 5 cases (5.81%), hypoxia occurred in 8 cases (9.30%), nausea in 8 cases (9.30%), vomiting 5 cases (5.81%) and post-operative gastrointestinal distension 13 cases (15.12%), mild renal insufficiency 3 cases (3.49%), fever (> 38.5 degrees C) 1 case(1. 16%) and severe post-operative pain 7 cases (8.14%). TEAS combined with general anesthesia is safe for patients undergoing heart valve replacement surgery under cardiopulmonary bypass. The key points of treatment in ICU are volume infusion, body temperature maintenance, and pain control.

  18. 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.

  19. The current clinical application of percutaneous heart valve replacement%经皮心脏瓣膜置换技术临床应用现状

    Institute of Scientific and Technical Information of China (English)

    丁仲如; 秦永文

    2006-01-01

    经皮心脏瓣膜置换技术(percutaneous heart valve replacement, PHVR )是近年介入心脏病学积极研究的又一新领域,包括经皮主动脉瓣置换percutaneous aortic valve replacement, PAVR )和经皮肺动脉瓣置换 ( percutaneous pulmonary valve replacement ,PPVR),目前已处于临床前期或初步临床应用中,由于其微创的特点具有广泛的应用前景。本研究简要介绍其研究应用现状,存在的问题及发展前景。

  20. Myocardial Oxygen Consumption and Efficiency in Aortic Valve Stenosis Patients With and Without Heart Failure

    DEFF Research Database (Denmark)

    Hansson, Nils Henrik Stubkjær; Sörensen, Jens; Harms, Hendrik Johannes;

    2017-01-01

    .61, respectively; Pnormal MVO2 and MEE (ie, the ability to convert energy into stroke work); however, patients with left ventricular ejection fraction strain greater than -12%; or paradoxical low-flow, low......BACKGROUND: Myocardial oxygen consumption (MVO2) and its coupling to contractile work are fundamentals of cardiac function and may be involved causally in the transition from compensated left ventricular hypertrophy to failure. Nevertheless, these processes have not been studied previously...... in patients with aortic valve stenosis (AS). METHODS AND RESULTS: Participants underwent (11)C-acetate positron emission tomography, cardiovascular magnetic resonance, and echocardiography to measure MVO2 and myocardial external efficiency (MEE) defined as the ratio of left ventricular stroke work...

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

    NARCIS (Netherlands)

    Bouma, Wobbe; Brugemann, Johan; Wijdh-den Hamer, Inez J.; Klinkenberg, Theo J.; Koene, Bart M.; Kuijpers, Michiel; Erasmus, Michiel E.; van der Horst, Iwan C. C.; Mariani, Massimo A.

    2012-01-01

    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 du

  2. Mitral valve surgery - minimally invasive

    Science.gov (United States)

    ... Saunders; 2012:chap 61. Otto CM, Bonow RO. Valvular heart disease. In: Mann DL, Zipes DP, Libby P, Bonow ... Editorial team. Related MedlinePlus Health Topics Heart Surgery Heart Valve Diseases Mitral Valve Prolapse Browse the Encyclopedia A.D. ...

  3. Effects of percutaneous mitral valve repair with Mitraclip on clinical status, ventricular remodeling and neurohormonal profile in patients with advanced heart failure and significant functional mitral regurgitation

    OpenAIRE

    Berardini, Alessandra

    2016-01-01

    The role of percutaneous mitral valve repair (PMVR) in patients with advanced heart failure (HF) and functional mitral regurgitation (FMR) is unclear. The aim of this study was to assess the effects (PMVR) therapy on clinical outcomes , left ventricular (LV) remodeling and neurohormonal changes in inoperable critical patients with chronically symptomatic FMR despite optical medical /electrical therapy and severe LV dysfunction. We analyzed the clinical and echocardiographic data of twenty-fiv...

  4. 瓣膜类型对主动脉瓣置换术后早期心功能影响的分析%Analysis of Valve Type Impact on Early Heart Function after Aortic Valve Replacement

    Institute of Scientific and Technical Information of China (English)

    闫成雷; 高长青; 李伯君; 叶卫华

    2012-01-01

    目的 分析主动脉瓣置换术后瓣膜类型对患者术后早期心功能的影响.方法 回顾性分析在我科行主动脉瓣置换手术的68例患者,年龄23 ~73(48.9±11.2)岁,其中男54例,女14例.病变类型:单纯主动脉瓣狭窄5例,主动脉瓣狭窄伴关闭不全21例,单纯主动脉瓣关闭不全42例.其中53例植入机械瓣,15例植入生物瓣.结果 无死亡及其他严重并发症.术后超声心动图示升主动脉内径[(37.9±5.3) vs (40.5±5.7) mm,P<0.05]较术前明显减小,术后左心室舒张末内径[(46.2±9.1) vs (58.9±11.6) mm,P<0.05]较术前明显减小,生物瓣及机械瓣两组患者术前及术后左心室舒张末内径、左心室射血分数、升主动脉直径等比较,差异无统计学意义,左心室舒张末内径和升主动脉直径的术前及术后的变化值比较,差异无统计学意义.结论 主动脉瓣置换术可改善患者心功能,瓣膜的类型在主动脉瓣置换术中对心功能的改善无影响.%Objective To analyze the impact of valve type on early heart function after aortic valve replacement. Methods We retrospectively analyzed 68 patients who underwent aortic valve replacement. Patients were aged (48.9±11.2) years on average ( range ,23 to 73 years ), including 54 males and 14 females. 5 patients had pure aortic stenosis,21 patients pure aortic insufficiency,and 42 patients aortic stenosis with insufficiency. Among them,53 underwent mechanical valve replacement,and 15 underwent bioprosthetic valve replacement. Results No death or other serious complications. The postoperative ascending aortic di-ametei{(37.9±5.3)vs(40. 5 ±5. 7 )mm,P <0. 05 land LVEDD[ ( 46. 2 ±9. 1 )vs(58.9 ±11.6)mm, P <0.05 Jwere both less than the preoperative data. Between bioprosthetic valve group and mechanical valve group,postoperative and preoperative ascending aortic diameter,LVEDD and LVEF were similar. Conclusion Aortic valve replacement can improve heart function, and valve type has

  5. Modeling the Mitral Valve

    Science.gov (United States)

    Kaiser, Alexander

    2016-11-01

    The mitral valve is one of four valves in the human heart. The valve opens to allow oxygenated blood from the lungs to fill the left ventricle, and closes when the ventricle contracts to prevent backflow. The valve is composed of two fibrous leaflets which hang from a ring. These leaflets are supported like a parachute by a system of strings called chordae tendineae. In this talk, I will describe a new computational model of the mitral valve. To generate geometry, general information comes from classical anatomy texts and the author's dissection of porcine hearts. An MRI image of a human heart is used to locate the tips of the papillary muscles, which anchor the chordae tendineae, in relation to the mitral ring. The initial configurations of the valve leaflets and chordae tendineae are found by solving solving an equilibrium elasticity problem. The valve is then simulated in fluid (blood) using the immersed boundary method over multiple heart cycles in a model valve tester. We aim to identify features and mechanisms that influence or control valve function. Support from National Science Foundation, Graduate Research Fellowship Program, Grant DGE 1342536.

  6. Cyclic stress-strain behavior of polymeric nonwoven structures for the use as artificial leaflet material for transcatheter heart valve prostheses

    Directory of Open Access Journals (Sweden)

    Arbeiter Daniela

    2017-09-01

    Full Text Available Xenogenic leaflet material, bovine and porcine pericardium, is widely used for the fabrication of surgically implanted and transcatheter heart valve prostheses. As a biological material, long term durability of pericardium is limited due to calcification, degeneration and homogeneity. Therefore, polymeric materials represent a promising approach for a next generation of artificial heart valve leaflets with improved durability. Within the current study we analyzed the mechanical performance of polymeric structures based on elastomeric materials. Polymeric cast films were prepared and nonwovens were manufactured in an electrospinning process. Analysis of cyclic stress-strain behavior was performed, using a universal testing machine. The uniaxial cyclic tensile experiments of the elastomeric samples yielded a non-linear elastic response due to viscoelastic behavior with hysteresis. Equilibrium of stress-strain curves was found after a specific number of cycles, for cast films and nonwovens, respectively. In conclusion, preconditioning was found obligatory for the evaluation of the mechanical performance of polymeric materials for the use as artificial leaflet material for heart valve prostheses.

  7. Surgical double valve replacement after transcatheter aortic valve implantation and interventional mitral valve repair.

    Science.gov (United States)

    Wendeborn, Jens; Donndorf, Peter; Westphal, Bernd; Steinhoff, Gustav

    2013-11-01

    Transcatheter aortic valve implantation, as well as interventional mitral valve repair, offer reasonable therapeutic options for high-risk surgical patients. We report a rare case of early post-interventional aortic valve prosthesis migration to the left ventricular outflow tract, with paravalvular leakage and causing severe mitral valve regurgitation. Initial successful interventional mitral valve repair using a clipped edge-to-edge technique revealed, in a subsequent procedure, the recurrence of mitral valve regurgitation leading to progressive heart failure and necessitating subsequent surgical aortic and mitral valve replacement.

  8. How the Heart Works

    Science.gov (United States)

    ... Works Explore How the Heart Works What Is... Anatomy Contraction Circulation Electrical System Heart Disease Related Topics Arrhythmia Congenital Heart Defects Coronary Heart Disease Heart Valve Disease How the Lungs Work Send a link to NHLBI to someone ...

  9. 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.

  10. Aortic valve surgery - open

    Science.gov (United States)

    ... Saunders; 2012:chap 61. Otton CM, Bowow RO. Valvular heart disease. In: Mann DL, Zipes DP, Libby P, Bonow ... Editorial team. Related MedlinePlus Health Topics Heart Surgery Heart Valve Diseases Browse the Encyclopedia A.D.A.M., Inc. ...

  11. Clinical information has low sensitivity for postmortem diagnosis of heart valve disease.

    Science.gov (United States)

    Coffey, Sean; Harper, Andrew R; Cairns, Benjamin J; Roberts, Ian Sd; Prendergast, Bernard D

    2017-07-01

    Accuracy of routinely collected information concerning cause of death is essential for public health and health systems planning. Since clinical examination has relatively low sensitivity for detection of valvular heart disease (VHD), mortality data based on clinical information alone might routinely underestimate the number of deaths due to VHD. We compared autopsy findings against premortem clinical information for 8198 consecutive adult postmortems (mean age 69.1 years, 61.3% men), performed in a single UK tertiary referral centre with on-site cardiac surgical facilities over a 10-year period (2004-2013) during which 21% of the adult population underwent postmortem examination. Following postmortem, VHD was the principal cause of death in 165 individuals (2.0%), a principal or contributory cause ('any cause') of death in 326 (4.0%) and an incidental (ie, non-causal) finding in a further 346 (4.2%). Clinical documentation of VHD before death was highly specific but relatively insensitive for postmortem identification of VHD as the principal (specificity 96.8%; 95% CI 96.4% to 97.2%; sensitivity 69.7%, 95% CI 62.1% to 76.6%) or any (specificity 98.1%; 95% CI 97.8% to 98.4%; sensitivity 68.4%, 95% CI 63.1% to 73.4%) cause of death. VHD (principally aortic stenosis, endocarditis and rheumatic heart disease) was newly noted at postmortem and listed as a cause of death in 142 individuals (1.7%). Clinical information recorded premortem is highly specific but relatively insensitive for the cause of death established at autopsy. Population-based mortality statistics that depend on premortem clinical information are likely to routinely underestimate the mortality burden of VHD. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  12. Design of a Fast Reversing Valve for Artificial Heart%一种用于人工心脏的快速换向阀的设计

    Institute of Scientific and Technical Information of China (English)

    金恒林; 胡晓兵

    2015-01-01

    To automatic reversing valve, high frequency, fast response speed and no hydraulic impact for the commutation, low noise are contradictory. In order to improve automatic reversing valve reversing frequency and reduce commutation delay time, and to ensure the stable reliable reversing without hydraulic clamping and hydraulic impact phenomena, a quick reversing electric valve for artificial heart was designed and made. The theoretical analysis shows that by changing the hole size, this quick reversing electric valve can be applied in many occasions. Experiments show that when the commutation frequencies are 24 and 82 times/min, using the fast reversing valve, the artificial heart blood pressure waveform is stable. It is shown that the stable and reliable fast directional valve can apply to high frequency occasions such as artificial heart.%自动换向阀的换向频率高、 换向响应速度快与换向平稳无液压冲击、 噪声低是互相矛盾的. 为了提升自动换向阀的换向频率和减少换向延迟时间, 并保证换向可靠无液压卡紧现象、 稳定无液压冲击现象, 设计并制作了一种用于人工心脏的快速换向电动阀. 理论分析表明: 通过改变阀通孔尺寸, 此快速换向电动阀在大、 小流量场合均能适用; 实验结果证明: 快速换向阀在换向频率为24次/min和82次/min时, 人工心脏血压波形稳定, 表明此快速换向阀能稳定可靠适用于高频的人工心脏等场合.

  13. Valve Repair or Replacement

    Science.gov (United States)

    ... valve surgery can be done using a robot. Robotic surgery does not require a large incision in the ... The Texas Heart Institute has a robot. With robotic surgery, the surgeon has a control console, a side ...

  14. Pulmonary valve replacement with a mechanical prosthesis. Promising results of 28 procedures in patients with congenital heart disease

    NARCIS (Netherlands)

    Hoendermis, Elke S.; den Hamer, Inez J.; Ebels, Tjark; Waterbolk, T

    2006-01-01

    Objective: Pulmonary valve replacement is performed increasingly late after correction of Tetralogy of Fallot. Most reports deal with pulmonary allografts as the valvar substitute of choice, although late deterioration and reoperation(s) are the rule. Mechanical valves are scarcely reported and if s

  15. Pulmonary valve replacement with a mechanical prosthesis. Promising results of 28 procedures in patients with congenital heart disease

    NARCIS (Netherlands)

    Hoendermis, Elke S.; den Hamer, Inez J.; Ebels, Tjark; Waterbolk, T

    Objective: Pulmonary valve replacement is performed increasingly late after correction of Tetralogy of Fallot. Most reports deal with pulmonary allografts as the valvar substitute of choice, although late deterioration and reoperation(s) are the rule. Mechanical valves are scarcely reported and if

  16. Transcatheter heart valve selection and permanent pacemaker implantation in patients with pre-existent right bundle branch block

    NARCIS (Netherlands)

    van Gils, Lennart; Tchetche, Didier; Lhermusier, Thibault; Abawi, Masieh; Dumonteil, Nicolas; Rodriguez Olivares, R; de Nicolas, Javier Molina Martin; Stella, Pieter R.|info:eu-repo/dai/nl/304814717; Carrié, Didier; De Jaegere, Peter P.; Van Mieghem, Nicolas M.

    2017-01-01

    Background-Right bundle branch block is an established predictor for new conduction disturbances and need for a permanent pacemaker (PPM) after transcatheter aortic valve replacement. The aim of the study was to evaluate the absolute rates of transcatheter aortic valve replacement related PPM implan

  17. Valvular interstitial cell seeded poly(glycerol sebacate) scaffolds: toward a biomimetic in vitro model for heart valve tissue engineering.

    Science.gov (United States)

    Masoumi, Nafiseh; Johnson, Katherine L; Howell, M Christian; Engelmayr, George C

    2013-04-01

    Tissue engineered replacement heart valves may be capable of overcoming the lack of growth potential intrinsic to current non-viable prosthetics, and thus could potentially serve as permanent replacements in the surgical repair of pediatric valvular lesions. However, the evaluation of candidate combinations of cells and scaffolds lacks a biomimetic in vitro model with broadly tunable, anisotropic and elastomeric structural-mechanical properties. Toward establishing such an in vitro model, in the current study, porcine aortic and pulmonary valvular interstitial cells (i.e. biomimetic cells) were cultivated on anisotropic, micromolded poly(glycerol sebacate) scaffolds (i.e. biomimetic scaffolds). Following 14 and 28 days of static culture, cell-seeded scaffolds and unseeded controls were assessed for their mechanical properties, and cell-seeded scaffolds were further characterized by confocal fluorescence and scanning electron microscopy, and by collagen and DNA assays. Poly(glycerol sebacate) micromolding yielded scaffolds with anisotropic stiffnesses resembling those of native valvular tissues in the low stress-strain ranges characteristic of physiologic valvular function. Scaffold anisotropy was largely retained upon cultivation with valvular interstitial cells; while the mechanical properties of unseeded scaffolds progressively diminished, cell-seeded scaffolds either retained or exceeded initial mechanical properties. Retention of mechanical properties in cell-seeded scaffolds paralleled the accretion of collagen, which increased significantly from 14 to 28 days. This study demonstrates that valvular interstitial cells can be cultivated on anisotropic poly(glycerol sebacate) scaffolds to yield biomimetic in vitro models with which clinically relevant cells and future scaffold designs can be evaluated.

  18. 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.

  19. A finite element model on effects of impact load and cavitation on fatigue crack propagation in mechanical bileaflet aortic heart valve.

    Science.gov (United States)

    Mohammadi, H; Klassen, R J; Wan, W-K

    2008-10-01

    Pyrolytic carbon mechanical heart valves (MHVs) are widely used to replace dysfunctional and failed heart valves. As the human heart beats around 40 million times per year, fatigue is the prime mechanism of mechanical failure. In this study, a finite element approach is implemented to develop a model for fatigue analysis of MHVs due to the impact force between the leaflet and the stent and cavitation in the aortic position. A two-step method to predict crack propagation in the leaflets of MHVs has been developed. Stress intensity factors (SIFs) are computed at a small initiated crack located on the leaflet edge (the worst case) using the boundary element method (BEM). Static analysis of the crack is performed to analyse the stress distribution around the front crack zone when the crack is opened; this is followed by a dynamic crack analysis to consider crack propagation using the finite element approach. Two factors are taken into account in the calculation of the SIFs: first, the effect of microjet formation due to cavitation in the vicinity of leaflets, resulting in water hammer pressure; second, the effect of the impact force between the leaflet and the stent of the MHVs, both in the closing phase. The critical initial crack length, the SIFs, the water hammer pressure, and the maximum jet velocity due to cavitation have been calculated. With an initial crack length of 35 microm, the fatigue life of the heart valve is greater than 60 years (i.e. about 2.2 x 10(9) cycles) and, with an initial crack length of 170 microm, the fatigue life of the heart valve would be around 2.5 years (i.e. about 9.1 x 10(7) cycles). For an initial crack length greater than 170 microm, there is catastrophic failure and fatigue cracking no longer occurs. A finite element model of fatigue analysis using Patran command language (PCL custom code) in MSC software can be used to evaluate the useful lifespan of MHVs. Similar methodologies can be extended to other medical devices under cyclic

  20. 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.

  1. Dental procedures, antibiotic prophylaxis, and endocarditis among people with prosthetic heart valves: nationwide population based cohort and a case crossover study.

    Science.gov (United States)

    Tubiana, Sarah; Blotière, Pierre-Olivier; Hoen, Bruno; Lesclous, Philippe; Millot, Sarah; Rudant, Jérémie; Weill, Alain; Coste, Joel; Alla, François; Duval, Xavier

    2017-09-07

    Objective To assess the relation between invasive dental procedures and infective endocarditis associated with oral streptococci among people with prosthetic heart valves.Design Nationwide population based cohort and a case crossover study.Setting French national health insurance administrative data linked with the national hospital discharge database.Participants All adults aged more than 18 years, living in France, with medical procedure codes for positioning or replacement of prosthetic heart valves between July 2008 and July 2014.Main outcome measures Oral streptococcal infective endocarditis was identified using primary discharge diagnosis codes. In the cohort study, Poisson regression models were performed to estimate the rate of oral streptococcal infective endocarditis during the three month period after invasive dental procedures compared with non-exposure periods. In the case crossover study, conditional logistic regression models calculated the odds ratio and 95% confidence intervals comparing exposure to invasive dental procedures during the three month period preceding oral streptococcal infective endocarditis (case period) with three earlier control periods.Results The cohort included 138 876 adults with prosthetic heart valves (285 034 person years); 69 303 (49.9%) underwent at least one dental procedure. Among the 396 615 dental procedures performed, 103 463 (26.0%) were invasive and therefore presented an indication for antibiotic prophylaxis, which was performed in 52 280 (50.1%). With a median follow-up of 1.7 years, 267 people developed infective endocarditis associated with oral streptococci (incidence rate 93.7 per 100 000 person years, 95% confidence interval 82.4 to 104.9). Compared with non-exposure periods, no statistically significant increased rate of oral streptococcal infective endocarditis was observed during the three months after an invasive dental procedure (relative rate 1.25, 95% confidence interval 0.82 to 1

  2. Task Force on Catastrophic Antiphospholipid Syndrome (APS) and Non-criteria APS Manifestations (I): catastrophic APS, APS nephropathy and heart valve lesions.

    Science.gov (United States)

    Cervera, R; Tektonidou, M G; Espinosa, G; Cabral, A R; González, E B; Erkan, D; Vadya, S; Adrogué, H E; Solomon, M; Zandman-Goddard, G; Shoenfeld, Y

    2011-02-01

    The objectives of the 'Task Force on Catastrophic Antiphospholipid Syndrome (APS) and Non-criteria APS Manifestations' were to assess the clinical utility of the international consensus statement on classification criteria and treatment guidelines for the catastrophic APS, to identify and grade the studies that analyse the relationship between the antiphospholipid antibodies and the non-criteria APS manifestations and to present the current evidence regarding the accuracy of these non-criteria APS manifestations for the detection of patients with APS. This article summarizes the studies analysed on the catastrophic APS, APS nephropathy and heart valve lesions, and presents the recommendations elaborated by the Task Force after this analysis.

  3. Pediatric heart surgery

    Science.gov (United States)

    Heart surgery - pediatric; Heart surgery for children; Acquired heart disease; Heart valve surgery - children ... the type of defect, and the type of surgery that was done. Many children recover completely and lead normal, active lives.

  4. 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

  5. 2349例心脏瓣膜置换术早期死亡原因分析%Early death causes in 2349 patients who receiving heart valve replacement

    Institute of Scientific and Technical Information of China (English)

    陈海生; 刘盛华; 钟志敏; 谢翠贤; 林秋伟

    2010-01-01

    目的 分析2349例心脏瓣膜置换术病人的死亡原因,以期进一步提高治疗水平.方法 1995年1月至2007年12月,2349例心脏瓣膜病病人接受人工心脏瓣膜置换手术.其中二尖瓣置换术(MVR)1333例,主动脉瓣置换术(AVR)271例,二尖瓣、主动脉瓣同期置换术(DVR)736例,三尖瓣置换术(TVR)9例.结果 早期病死率1995年至1999年6.81%,2000年至2004年3.22%,2005年至2007年2.82%.全组总早期病死率3.40%.结论 心脏瓣膜置换术早期死亡的原因主要是低心排血量综合征、肾功能衰竭、心律失常、肺部感染、脑血管意外、左室破裂和多器官系统功能衰竭等.%Objective The early causes of death were analyze in 2349 patients who had undergone heart valve replacement.Methods Methods From January 1995 to December 2007,2349 patients with heart valve diseases received heart valve replacement.1109 cases were male and 1240 were female.The mean age of the patients was(41±19)years old.1962 cases had rheumatic heart valve disease,308 had congenital heart valve disease,39 had infective endocarditis,29 underwent reintervention by heart valve replacement,11 had Marfan syndrome.34 cases with coronary heart disease underwent heart valve prosthesis implantation and coronary artery bypass grafting.Mitral valve replacement(MVR)was performed in 1333 patients,aortic valve replacement(AVR)in 271,double valves replacement(DVR)in 736 and tricuspid valve replacement(TVR)in 9.There were 3075 mechanical valves and 10 bioprosthetic valves.Results From 1995 to 1999,death occurred in 16 of the 235 cases,early mortality rate was 6.81%.From 2000 to 2004,death occurred in 35 of the 1087 cases,early mortality rate was 3.22%.From 2005 to 2007,there were 29 deaths among 1027 cases,with an early mortality rate of 2.82%.Overall early mortality rate was 3.40%.The early mortality rate was 2.32%(31 in 1333 cases)in patients who underwent MVR,3.32% (9 in 271)in patients who underwent AVR,5.24%(40 in 736)in

  6. D-dimer to guide the intensity of anticoagulation in Chinese patients after mechanical heart valve replacement: a randomized controlled trial.

    Science.gov (United States)

    Zhang, L; Zheng, X; Long, Y; Wu, M; Chen, Y; Yang, J; Liu, Z; Zhang, Z

    2017-08-01

    Essentials Low anticoagulation intensity reduces bleeding but increases thrombosis during warfarin therapy. Elevated D-dimer level is associated with increased thrombosis events. D-dimer can be used to find potential thrombosis in those receiving low intensity therapy. D-dimer-guided therapy may be the optimal strategy for those with mechanical heart valve replacement. Background Controversies remain regarding the optimal anticoagulation intensity for Chinese patients after mechanical heart valve replacement despite guidelines having recommended a standard anticoagulation intensity. Objectives To investigate whether D-dimer could be used to determine the optimal anticoagulation intensity in Chinese patients after mechanical heart valve replacement. Patients/Methods This was a prospective, randomized controlled clinical study. A total of 748 patients following mechanical heart valve replacement in Wuhan Asia Heart Hospital were randomized to three groups at a ratio of 1 : 1 : 1. Patients in two control groups received warfarin therapy based on constant standard intensity (international normalized ratio [INR], 2.5-3.5; n = 250) and low intensity (INR, 1.8-2.6; n = 248), respectively. In the experimental group (n = 250), warfarin therapy was initiated at low intensity, then those with elevated D-dimer levels were adjusted to standard intensity. All patients were followed-up for 24 months until the occurrence of endpoints, including bleeding events, thrombotic events and all-cause mortality. Results A total of 718 patients were included in the analysis. Fifty-three events occurred during follow-up. There was less hemorrhage (3/240 vs. 16/241; hazard ratio [HR], 0.18; 95% confidence interval [CI], 0.07-0.45) and all-cause mortality (4/240 vs. 12/241; HR, 0.33; 95% CI, 0.12-0.87) observed in the D-dimer-guided group than in the standard-intensity group. A lower incidence of thrombotic events was also observed in the D-dimer-guided group when compared with the

  7. 100 Cases of Artificial Heart Valve Replacements%心脏人工机械瓣膜置换术100例报告

    Institute of Scientific and Technical Information of China (English)

    孔维生; 郑秀木; 杨谦; 郭水源; 张健然

    2001-01-01

    Objective:To review the experience of the heart valve replacements.Methods:All patients underwent general anesthesia under middle hypothermic cardiopulmonary bypass(CBP).Operations included MVR in 65 cases,AVR in 19 cases,MAVR in 16 cases.Second operations had 14 patients of restenosis after mitral valve stenosis dilatation.Additional procedures included tricuspid valve De Vegas annuloplasty in 15 cases.Results:93 patients recovered uneventfully and returned to normal life.There were 7 cases of postoperative death with a mortalily of 7%.Conclusion:Main factor of heart valve diseases suffered from RHD.Infective endocarditis and degenerate heart diseases were often seen in the clinic.The study suggests that the surgical early diagnosis and effective treatment can achieve excellent outcome with low complications and high cure rates.%目的 总结100例心脏瓣膜置换术。方法 全组均在全麻体外循环中低温下手术,行二尖瓣置换(MVR)65例,主动脉瓣置换(AVR)19例,二尖瓣和主动脉瓣置换(MAVR)16例,其中14例是二尖瓣狭窄术后再狭窄行置换术,同时行三尖瓣De Vegas环缩术15例。结果 术后93例痊愈出院,围手术期死亡7例,均为风心病患者。结论 风湿性心脏病(RHD)是导致心脏瓣膜损毁的主要病因,感染性心内膜炎(IE)和退行性变也是较常见的因素,而早期诊断、及时手术是提高治愈率、降低并发症的关键。

  8. 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 ...

  9. Transvalvular mitral regurgitation following mitral valve replacement a diagnostic dilemma

    OpenAIRE

    U S Dinesh Kumar; Umesh Nareppa; Shyam Prasad Shetty; Murugesh Wali

    2015-01-01

    After mitral valve replacement with a prosthetic valve, the valve should be competent and there should not be any residual prosthetic valve regurgitation. Transvalvular residual prosthetic valve regurgitation are difficult to diagnose and quantify. we are reporting interesting TEE images as a diagnostic dilemma in a case of transvalvular mitral regurgitation following mitral valve replacement secondary to entrapment of sub-valvular apparatus in a Chitra mechanical heart valve.

  10. Heart valve surgery: EuroSCORE vs. EuroSCORE II vs. Society of Thoracic Surgeons score

    Directory of Open Access Journals (Sweden)

    Muhammad Sharoz Rabbani

    2014-12-01

    Full Text Available Background This is a validation study comparing the European System for Cardiac Operative Risk Evaluation (EuroSCORE II with the previous additive (AES and logistic EuroSCORE (LES and the Society of Thoracic Surgeons’ (STS risk prediction algorithm, for patients undergoing valve replacement with or without bypass in Pakistan. Patients and Methods Clinical data of 576 patients undergoing valve replacement surgery between 2006 and 2013 were retrospectively collected and individual expected risks of death were calculated by all four risk prediction algorithms. Performance of these risk algorithms was evaluated in terms of discrimination and calibration. Results There were 28 deaths (4.8% among 576 patients, which was lower than the predicted mortality of 5.16%, 6.96% and 4.94% by AES, LES and EuroSCORE II but was higher than 2.13% predicted by STS scoring system. For single and double valve replacement procedures, EuroSCORE II was the best predictor of mortality with highest Hosmer and Lemmeshow test (H-L p value (0.346 to 0.689 and area under the receiver operating characteristic (ROC curve (0.637 to 0.898. For valve plus concomitant coronary artery bypass grafting (CABG patients actual mortality was 1.88%. STS calculator came out to be the best predictor of mortality for this subgroup with H-L p value (0.480 to 0.884 and ROC (0.657 to 0.775. Conclusions For Pakistani population EuroSCORE II is an accurate predictor for individual operative risk in patients undergoing isolated valve surgery, whereas STS performs better in the valve plus CABG group.

  11. 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...

  12. 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

    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...... 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...

  13. Single-center comparative outcomes of the Edwards SAPIEN and Medtronic Melody transcatheter heart valves in the pulmonary position.

    Science.gov (United States)

    Faza, Nadeen; Kenny, Damien; Kavinsky, Clifford; Amin, Zahid; Heitschmidt, Mary; Hijazi, Ziyad M

    2013-10-01

    Two transcatheter pulmonary valve replacement (tPVR) systems (Edwards SAPIEN and Medtronic Melody) are available; however, comparative studies evaluating outcome data are lacking. The aim of this study was to compare short- with medium-term outcome data of these valves in the pulmonary position from a single institution. Retrospective data analysis of all patients undergoing tPVR from April 2008 until April 2012. Pre-procedural investigations, patient demographics, procedural hemodynamics, and clinical and echocardiographic follow-up data were included. Data are presented as mean ± standard deviation. Thirty-three patients underwent successful tPVR (SAPIEN (S) n = 20, Melody (M) n = 13). Patient age and weight were similar between the two groups. Primary indication included regurgitation (S (n = 2), M (n = 3)), stenosis (S (n = 13), M (n = 7)), or mixed (S (n = 5), M (n = 3)). There was no difference in pre-procedural peak Doppler gradients across the pulmonary outflow (S = 47.73 ± 21.14 mm Hg, M = 42.62 ± 15.59 mm Hg, P = 0.46). All but one patient underwent pre-stenting prior to valve implantation. Immediately following valve deployment, the transvalvar gradient was not statistically different between the two groups (S = 11.5 ± 8.07 mm Hg, M = 8.15 ± 4.56 mm Hg, P = 0.18). There were no procedural deaths. Follow-up mean pulmonary Doppler gradients were higher with the SAPIEN cohort (18.43 ± 9.06 mm Hg (S) and 11.17 ± 5.24 mm Hg (M), P = 0.016); however, no differences were seen when similar procedural epochs were assessed. All but one patient remained with PR grade = 2. In a single-center series, the SAPIEN and Melody valves demonstrated comparable medium-term valve function. Greater residual gradients with the SAPIEN valve may represent a more conservative early pre-stenting approach with this valve. Copyright © 2012 Wiley Periodicals, Inc.

  14. 心脏人工瓣膜的超声心动图评估%Evaluation for artificial heart valve echocardiographic

    Institute of Scientific and Technical Information of China (English)

    王秀娟

    2015-01-01

    超声心动图是目前最有价值的无创检查技术。本文就人工瓣膜的超声评估作一简单综述。%Echocardiography is the most valuable noninvasive examination technology. In this paper, the ultrasound assessment of artificial valve were reviewed simply.

  15. 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...

  16. Role of vortices in cavitation formation in the flow at the closure of a bileaflet mitral mechanical heart valve.

    Science.gov (United States)

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

    2012-03-01

    Bubble cavitation occurs in the flow field when local pressure drops below vapor pressure. One hypothesis states that low-pressure regions in vortices created by instantaneous valve closure and occluder rebound promote bubble formation. To quantitatively analyze the role of vortices in cavitation, we applied particle image velocimetry (PIV) to reduce the instantaneous fields into plane flow that contains information about vortex core radius, maximum tangential velocity, circulation strength, and pressure drop. Assuming symmetrical flow along the center of the St. Jude Medical 25-mm valve, flow fields downstream of the closing valve were measured using PIV in the mitral position of a circulatory mock loop. Flow measurements were made during successive time phases immediately following the impact of the occluder with the housing (O/H impact) at valve closing. The velocity profile near the vortex core clearly shows a typical Rankine vortex. The vortex strength reaches maximum immediately after closure and rapidly decreases at about 10 ms, indicating viscous dissipation; vortex strength also intensifies with rising pulse rate. The maximum pressure drop at the vortex center is approximately 20 mmHg, an insignificant drop relative to atmospheric vapor pressures, which implies vortices play a minor role in cavitation formation.

  17. 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.

  18. 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

  19. 人工心脏瓣膜再次置换手术的体外循环管理%MANAGEMENT OF CARDIOPULMONARY BYPASS IN THE SECOND HEART VALVE REPLACEMENT

    Institute of Scientific and Technical Information of China (English)

    李美霞; 田毅; 符白嫩; 侯春燕

    2011-01-01

    [目的]回顾总结30例再次心脏瓣膜置换手术的体外循环(CPB)管理和方法.[方法]对2005年1月-2010年1月的30例再次心脏瓣膜置换手术患者,术前进行全面评估,充分准备,术中采用适宜的插管部位,自体血液回收.中一高流量,维持平均动脉压(MAP) 50-80 mmHg,[结果]二尖瓣或主动脉瓣单瓣置换16例;二尖瓣+主动脉瓣置换7例;二尖瓣+主动脉瓣+三尖瓣置换4例;三尖瓣置换3例,无手术死亡,术后死亡2例.[结论]再次心脏瓣膜置换手术中,术前充分准备,选择适当插管部位,术中加强血液保护、心肌保护,采取综合措施是保证CPB成功的关键.%[Objective] To conclude the management experience of cardiopulmonaiy bypass in the surgery of second heart valve replacement [Methods] Collected 30 patients undergoing the second heart valve replacement from January 2005 to January 2010, we took overall evaluation and thoroughly preparation before the operation, catheter at suitable site, autotrans-fusion, middle-high rate of flow and maintained MAP between 50-80mmHg. [Results] There was no death cases during operation of all the patients, of which 16 patients undergoing single initial valve or aortic valve replacement, 7 patients undergoing both mitral valve and aortic valve replacement, 4 patients undergoing mitral valve, aortic valve and tricuspid valve replacement, 3 patients undergoing tricuspid valve replacement, but 2 deaths after operation. [Conclusion] During the second heart valve replacement surgery, the preparation before operation, suitable catheter site, intensive blood protection and myocardium protection and taking combined intervention are the keys to guarantee the success of cardiopulmonary bypass.

  20. 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.

  1. Analysis of 427 cases of heart valve replacement%心脏瓣膜置换术427例疗效分析

    Institute of Scientific and Technical Information of China (English)

    刘宁; 刘伟; 李鹏; 何茂鑫

    2008-01-01

    目的 总结心脏瓣膜置换术的手术效果,探讨影响手术疗效的主要因素及手术适应证的选择.方法 回顾性分析1985年2月至2006年12月427例心脏瓣膜置换术的资料.427例中男196例,女231例;平均年龄(45±3)岁.风湿性瓣膜病403例(94.3%),非风湿性瓣膜病24例(5.7%).其中二尖瓣置换术302例,主动脉瓣置换术46例,主动脉辩与二尖瓣置换术65例,再次二尖瓣置换术14例;同期行三尖瓣成形术231例.结果 术后早期并发症46例(10.8%),手术死亡11例(2.58%).主要死亡原因为心力衰竭和多脏器功能衰竭.影响瓣膜置换术后早期疗效的主要危险因素是术前巨大左室,收缩功能减弱,心功能Ⅳ级,肾功能衰竭,严重感染,术后低心排综合征和多脏器功能衰竭.结论 合理选择手术时机,保留瓣下结构,积极纠正三尖瓣病变和心律失常,术中良好的心肌保护是提高手术疗效的关键.%Objective To summarize the experience of valve replacements and the operative indication. Methods The follow-up data of 427 patients were analyzed retrespectively between Feb. 1985 and Dec. 2006,196 males ,231 females, mean age was(45±3) years. Rheumatic valvular disease presented in 403 (94.3%)patients and non-rheumatic valvular disease in 24 patients (5.7%). 302 patients had mitral valve replacement (MVR), 46 had aortic valve replacement(AVR), 65 had MVR AVR, 14 had second MVR. Tricuspid valve annuloplasty in 231 patients. Results The early postoperative complication and mortality rote were 10.8% and 2. 58%. The major cause of early death was heart failure or multiple organ function failure. The main factors influencing the early surgical results were preoperative severe left ventricular enlargement and systolic dysfunction. Included leart function class Ⅳ(NYHA), renal failure, severe infection, postoperative low cardiac output and multiple organs function incompetence. Conclusion Timely decision of the operation for heart valve

  2. 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.

  3. COMPARATIVE EFFECTS OF MONOTHERAPY WITH MAGNESIUM AND COMBINED THERAPY WITH MAGNESIUM AND Β-BLOCKER ON PRIMARY MITRAL VALVE PROLAPSE WITH HEART RHYTHM DISORDERS

    Directory of Open Access Journals (Sweden)

    E. G. Nurtdinova

    2007-01-01

    Full Text Available Aim. To compare effects of monotherapy with magnesium and combined therapy with magnesium and β-blocker on primary mitral valve prolapse (MVP with heart rhythm disorders.Material and methods. 71 patients with primary MVP 1-2 degree and heart rhythm disorders were involved in the study. The patients were split into three groups. Group I (25 persons received monotherapy with magnesium orotate at a dose of 1-3 g per day; group II (28 persons received combined therapy with magnesium orotate and betaxolol. The control group (18 persons received no therapy. Initially and after 12 weeks of observation all the patients underwent electrocardiography (ECG, ECG-Holter monitoring, echocardiography and autonomic balance assessment by A.M. Vein’s questionnaire.Results. In 12 weeks of treatment groups I and II showed positive dynamics in the MVP manifestations, including significant reduction in severity of the autonomic dysfunction syndrome, ECG positive dynamics, antiarrhythmic effect, decrease in the degree of prolapse, diminution of mitral regurgitation and left auricle volumes. More substantial hemodynamic effects were found in the group of patients who received combination therapy.Conclusion. Combined therapy has proven advantages in comparison with magnesium monotherapy in terms of daily quantity of extrasystoles, reduction in heart rate, decrease in autonomic disfunction and normalization of intracardiac hemodynamics.

  4. 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.

  5. 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

    -benefit will be assessed. A mixed-method design will be used to evaluate qualitative and quantitative findings, encompassing a survey-based study before the trial and a qualitative pre- and post-intervention study. CONCLUSION: This randomized clinical trial will contribute with evidence of whether cardiac rehabilitation...... (VO2 peak) measured by cardiopulmonary exercise testing with ventilatory gas analysis. The secondary outcome is self-assessed mental health measured by the standardized questionnaire Short Form-36. Long-term healthcare utilization and mortality as well as biochemistry, echocardiography and cost...... should be provided after heart valve surgery. The study is approved by the local regional Research Ethics Committee (H-1-2011-157), and the Danish Data Protection Agency (j.nr. 2007-58-0015). TRIAL REGISTRATION: Trial registered 16 March 2012; ClinicalTrials.gov ( NCT01558765 )....

  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. Testing of RPMI-1640 as a Nutrient Medium for Fresh Semilunar Valve Storage.

    Science.gov (United States)

    1979-01-01

    Antibiotics. Many different media formulas for heart valve storage are currently on the market . Since Medium 199 was the medium most widely used at the...NUTRIENT MEDIUM FOR FRESH SEMILUNAR VALVE STORAGE By James Beverly Nichols V RPMI 1640 medium was evaluated for heart valve storage. Valves from 16 dogs...the RPtI 1640 did not cause appreciable tissue death. All valves remained viable. The histopatholoqical estimates of heart valve viability ranged

  8. Combined treatment of ulinastatin and tranexamic acid provides beneficial effects by inhibiting inflammatory and fibrinolytic response in patients undergoing heart valve replacement surgery.

    Science.gov (United States)

    Chen, Ting-Ting; Jiandong-Liu; Wang, Gang; Jiang, Sheng-Li; Li, Li-Bing; Gao, Chang-Qing

    2013-02-01

    To investigate the effect of ulinastatin and tranexamic acid administered alone or in combination on inflammatory cytokines and fibrinolytic system in patients undergoing heart valve replacement surgery during cardiopulmonary bypass (CPB). CPB-induced fibrinolytic hyperfunction and systemic inflammatory response syndrome (SIRS) are the leading causes responsible for the occurrence of postsurgical complications such as postsurgical cardiac insufficiency and lung injury, which may lead to an increase in postsurgical bleeding, prolongation of hospital stay, and increased costs. One hundred twenty patients undergoing heart valve replacement surgery during CPB were randomly assigned into 4 groups of 30 patients each: blank control group (Group C), tranexamic acid group (Group T), ulinastatin group (Group U), and tranexamic acid-ulinastatin combination group (Group D). Physiological saline, tranexamic acid, ulinastatin, and a combination of tranexamic acid and ulinastatin were given to each group, respectively. Arterial blood was collected from the radial artery at 4 time points: after induction of anesthesia (T1), unclamping the ascending aorta (T2), and at 1 hour (T3) and 24 hours (T4) after CPB. The levels of plasma tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), neutrophil elastase (NE), and the concentrations of tissue plasminogen activator (t-PA) and α2-antiplasmin (α2-AP) were detected. The changes in the volume of pericardial mediastinal drainage after surgery were observed and recorded. The plasma TNF-α, IL-6, and NE levels significantly increased in patients from all 4 groups at time points of T2, T3, and T4 in comparison to those before CPB (P surgery (P surgery.

  9. Pediatric heart surgery - discharge

    Science.gov (United States)

    ... discharge; Heart valve surgery - children - discharge; Heart surgery - pediatric - discharge; Heart transplant - pediatric - discharge ... Geme JW, Schor NF, eds. Nelson Textbook of Pediatrics . 20th ed. Philadelphia, PA: Elsevier; 2016:chap 434. ...

  10. Selection and application of scaffold materials for tissue engineered heart valves%组织工程心脏瓣膜支架材料的选择与应用

    Institute of Scientific and Technical Information of China (English)

    哈里木·克里木; 王磊; 齐海

    2011-01-01

    背景:支架材料的选择在组织工程心脏瓣膜中起着至关重要的作用,支架材料的选择也就影响着组织工程心脏瓣膜的构建效果.目的:评价组织工程心脏瓣膜支架材料的的优缺点,并对其选择进行总结.方法:以 "组织工程,心脏瓣膜,支架材料,生物相容性",为中文关键词;以:"tissue engineering,heart valves,scaffold material,biocompatibility" 为英文关键词,采用计算机检索1993-01/2009-10相关文章.纳入与有关生物材料与组织工程心脏瓣膜的相关的文章;排除重复研究及Meta分析类文章.结果与结论:人工合成高分子材料有更大的可控性,可预先塑性,大量制备,孔径和孔隙率较容易控制,成本低廉;天然生物材料和合成高分子材料都存在一定不足,将人工可降解材料与天然材料相结合构建瓣膜支架,发挥两者各自的优势构建出性能良好的组织工程心脏瓣膜.组织工程心脏瓣膜的研究前景广阔.但距离临床应用还有很长的路要走,相信随着研究的不断深入以及支架材料的不断优化对组织工程心脏瓣膜构建方法的改进,在不远的将来造福于广大心脏瓣膜病患者.%BACKGROUND: The choice of scaffold materials in heart valve tissue engineering plays a vital role, which affects the constructionof tissue-engineered heart valve.OBJECTIVE: To review the advantages and disadvantages of tissue engineered heart valve scaffold materials.METHODS: A computer based search was performed for articles about biomaterials and tissue engineered heart valve publishedfrom January 1993 to October 2009 with the keywords of “tissue engineering, heart valves, scaffold material, biocompatibility” inChinese and English. Repetitive studies and Meta analysis were excluded.RESULTS AND CONCLUSION: Synthetic polymer materials with greater controllability can be pre -plastic. The pore size andporosity of the synthetic polymer materials is easy to control, and the cost

  11. 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.

  12. Arterial pulse wave dynamics after percutaneous aortic valve replacement: fall in coronary diastolic suction with increasing heart rate as a basis for angina symptoms in aortic stenosis.

    Science.gov (United States)

    Davies, Justin E; Sen, Sayan; Broyd, Chris; Hadjiloizou, Nearchos; Baksi, John; Francis, Darrel P; Foale, Rodney A; Parker, Kim H; Hughes, Alun D; Chukwuemeka, Andrew; Casula, Roberto; Malik, Iqbal S; Mikhail, Ghada W; Mayet, Jamil

    2011-10-04

    Aortic stenosis causes angina despite unobstructed arteries. Measurement of conventional coronary hemodynamic parameters in patients undergoing valvular surgery has failed to explain these symptoms. With the advent of percutaneous aortic valve replacement (PAVR) and developments in coronary pulse wave analysis, it is now possible to instantaneously abolish the valvular stenosis and to measure the resulting changes in waves that direct coronary flow. Intracoronary pressure and flow velocity were measured immediately before and after PAVR in 11 patients with unobstructed coronary arteries. Using coronary pulse wave analysis, we calculated the intracoronary diastolic suction wave (the principal accelerator of coronary blood flow). To test physiological reserve to increased myocardial demand, we measured at resting heart rate and during pacing at 90 and 120 bpm. Before PAVR, the basal myocardial suction wave intensity was 1.9±0.3×10(-5) W · m(-2) · s(-2), and this increased in magnitude with increasing severity of aortic stenosis (r=0.59, P=0.05). This wave decreased markedly with increasing heart rate (β coefficient=-0.16×10(-4) W · m(-2) · s(-2); Pcoronary physiological reserve with increasing heart rate (β coefficient=0.9×10(-3) W · m(-2) · s(-2); P=0.014). In aortic stenosis, the coronary physiological reserve is impaired. Instead of increasing when heart rate rises, the coronary diastolic suction wave decreases. Immediately after PAVR, physiological reserve returns to a normal positive pattern. This may explain how aortic stenosis can induce anginal symptoms and their prompt relief after PAVR. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT01118442.

  13. Porcine Tricuspid Valve Anatomy and Human Compatibility

    DEFF Research Database (Denmark)

    Waziri, Farhad; Lyager Nielsen, Sten; Hasenkam, J. Michael

    2016-01-01

    before clinical use. The study aim was to evaluate and compare the tricuspid valve anatomy of porcine and human hearts. METHODS: The anatomy of the tricuspid valve and the surrounding structures that affect the valve during a cardiac cycle were examined in detail in 100 fresh and 19 formalin...

  14. 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.

  15. 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......, stroke, and New York Heart Association functional class. RESULTS: Modes of bioprosthesis failure were stenosis (n = 181 [39.4%]), regurgitation (n = 139 [30.3%]), and combined (n = 139 [30.3%]). The stenosis group had a higher percentage of small valves (37% vs 20.9% and 26.6% in the regurgitation...

  16. Minimally Invasive Mitral Valve Replacement and Transfemoral Aortic Valve Implantation.

    Science.gov (United States)

    Rustenbach, Christian; Baumbach, Hardy; Hill, Stephan; Franke, Ulrich F W

    2015-01-01

    The case is reported of a symptomatic elderly patient with severe mitral regurgitation, severe aortic valve stenosis, and coronary heart disease. The coronary artery disease had been interventionally treated four years previously with stent implantation into the right coronary artery. Published studies have shown that a combination of mitral and aortic valve surgery is associated with a significantly increased risk of mortality and morbidity, particularly in elderly patients. In the present patient, both valvular malformations were successfully treated with a single-step interdisciplinary approach, namely an initial surgical mitral valve replacement followed by transfemoral transcatheter aortic valve replacement.

  17. Heart valve papillary fibroelastoma associated with cardioembolic cerebral events Fibroelastoma papilífero de valva cardíaca associado a eventos cerebrais cardioembólicos

    Directory of Open Access Journals (Sweden)

    Luciano Cabral Albuquerque

    2011-12-01

    Full Text Available Papillary fibroelastomas of the heart valves are benign, slow-growing, rare tumors of the heart. This tumor represents a potential cause of systemic embolism, stroke, myocardial infarction and sudden death. Early diagnosis is very important, as surgical excision of these tumors can prevent cerebrovascular and cardiovascular complications. Diagnosis is usually made by transesophageal echocardiogram. We describe two cases of patients with papillary fibroelastomas causing cardioembolic cerebral events, which underwent successful surgical treatment. The authors present a brief review of the literature.Fibroelastoma papilífero é um tumor benigno, raro e de crescimento lento, que geralmente tem origem no endocárdio das valvas cardíacas. Este tumor representa uma causa potencial de embolia sistêmica, infarto agudo do miocárdio, acidente vascular cerebral e morte súbita. O diagnóstico precoce é fundamental, já que a excisão cirúrgica pode evitar complicações cerebrovasculares e cardiovasculares. O diagnóstico geralmente é feito pelo ecocardiograma transesofágico. Neste trabalho, são descritos dois casos de pacientes com fibroelastoma papilífero de valva aórtica, causando eventos cerebrais cardioembólicos, que foram submetidos com sucesso a tratamento cirúrgico. Apresenta-se, ainda, uma sucinta revisão da literatura.

  18. Cardiac troponin-I concentration, myocardial arteriosclerosis, and fibrosis in dogs with congestive heart failure because of myxomatous mitral valve disease.

    Science.gov (United States)

    Falk, T; Ljungvall, I; Zois, N E; Höglund, K; Olsen, L H; Pedersen, H D; Häggström, J

    2013-01-01

    Few previous studies have investigated the association between biomarkers and cardiac disease findings in dogs with naturally occurring myxomatous mitral valve disease (MMVD). To investigate if histopathological changes at necropsy could be reflected by in vivo circulating concentrations of cTnI and aldosterone, and renin activity, in dogs with naturally occurring congestive heart failure because of MMVD. Fifty privately owned dogs with MMVD and heart failure. Longitudinal Study. Dogs were prospectively recruited and examined by clinical and echocardiographical examination twice yearly until time of death. Blood was stored for batched analysis of concentrations of cTnI and aldosterone, and renin activity. All dogs underwent a standardized necropsy protocol. cTnI were associated with echocardiographic left ventricular end-diastolic dimension (P fibrosis (P fibrosis in the papillary muscles (P disease variables investigated. Cardiac fibrosis and arteriosclerosis in dogs with MMVD are reflected by circulating cTnI concentration, but not by aldosterone concentration or renin activity. Cardiac troponin I could be a valuable biomarker for myocardial fibrosis in dogs with chronic cardiac diseases. Copyright © 2013 by the American College of Veterinary Internal Medicine.

  19. 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.)

  20. Computed tomography assessment for transcatheter aortic valve in valve implantation: The vancouver approach to predict anatomical risk for coronary obstruction and other considerations.

    Science.gov (United States)

    Blanke, Philipp; Soon, Jeanette; Dvir, Danny; Park, Jong K; Naoum, Christopher; Kueh, Shaw-Hua; Wood, David A; Norgaard, Bjarne L; Selvakumar, Kapilan; Ye, Jian; Cheung, Anson; Webb, John G; Leipsic, Jonathon

    Valve-in-valve implantation of a transcatheter heart valve into a failed bioprosthetic heart valve has emerged as a treatment alternative to repeat conventional surgery. This requires careful pre-procedural assessment using non-invasive imaging to identify patients at risk for procedure related adverse events, such as ostial coronary occlusion. Herein we report how to comprehensively assess aortic root anatomy using computed tomography prior to transcatheter valve implantation for failed bioprosthetic aortic valves.

  1. Telemedicine-guided, very low-dose international normalized ratio self-control in patients with mechanical heart valve implants.

    Science.gov (United States)

    Koertke, Heinrich; Zittermann, Armin; Wagner, Otto; Secer, Songuel; Sciangula, Alfonso; Saggau, Werner; Sack, Falk-Udo; Ennker, Jürgen; Cremer, Jochen; Musumeci, Francesco; Gummert, Jan F

    2015-06-01

    To study in patients performing international normalized ratio (INR) self-control the efficacy and safety of an INR target range of 1.6-2.1 for aortic valve replacement (AVR) and 2.0-2.5 for mitral valve replacement (MVR) or double valve replacement (DVR). In total, 1304 patients undergoing AVR, 189 undergoing MVR and 78 undergoing DVR were randomly assigned to low-dose INR self-control (LOW group) (INR target range, AVR: 1.8-2.8; MVR/DVR: 2.5-3.5) or very low-dose INR self-control once a week (VLO group) and twice a week (VLT group) (INR target range, AVR: 1.6-2.1; MVR/DVR: 2.0-2.5), with electronically guided transfer of INR values. We compared grade III complications (major bleeding and thrombotic events; primary end-points) and overall mortality (secondary end-point) across the three treatment groups. Two-year freedom from bleedings in the LOW, VLO, and VLT groups was 96.3, 98.6, and 99.1%, respectively (P = 0.008). The corresponding values for thrombotic events were 99.0, 99.8, and 98.9%, respectively (P = 0.258). The risk-adjusted composite of grade III complications was in the per-protocol population (reference: LOW-dose group) as follows: hazard ratio = 0.307 (95% CI: 0.102-0.926; P = 0.036) for the VLO group and = 0.241 (95% CI: 0.070-0.836; P = 0.025) for the VLT group. The corresponding values of 2-year mortality were = 1.685 (95% CI: 0.473-5.996; P = 0.421) for the VLO group and = 4.70 (95% CI: 1.62-13.60; P = 0.004) for the VLT group. Telemedicine-guided very low-dose INR self-control is comparable with low-dose INR in thrombotic risk, and is superior in bleeding risk. Weekly testing is sufficient. Given the small number of MVR and DVR patients, results are only valid for AVR patients. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

  2. The Analysis of Early-Term Surgical Complications Following Mechanical Heart Valve Replacement%人工机械瓣膜替换术后早期并发症分析

    Institute of Scientific and Technical Information of China (English)

    杜心灵; 孙宗全; 张宏超; 苏伟; 蓝鸿均

    2001-01-01

    1987年1月至2000年4月,共施行人工机械瓣膜替换手术700例,其中二尖瓣替换术398例,主动脉瓣替换术81例,二尖瓣和主动脉瓣替换术213例,三尖瓣替换术8例.158例患者术中和术后早期发生并发症,发生率为22.6%,死亡44例,死亡率6.3%.死亡原因主要为低心排出量综合征、严重感染和心律失常等.%From Jan. 1987 to Apr. 2000, 700 patients received mechanical heart valve insertion in our hospital. Among them 398 underwent mitral valve replacement, 81 aortic valve replacement, 213 mitral and aortic valve replacement, and 8 tricuspid valve replacement. Surgical complications occurred in 158 cases (22.6 %) during or after operation. Forty-four patients died with a mortality rate of 6.3 %. Low cardiac output syndrome, serious infection and arrhythmia were the main causes of death.

  3. 超声心动图评价心脏机械瓣功能的长期变化趋势%Long term change trend of echocardiographic evaluation of mechanical heart valve function

    Institute of Scientific and Technical Information of China (English)

    陈文斌; 蔡震宇

    2015-01-01

    Objective To explore the long term change trend of echocardiographic evaluation of mechanical heart valve function after mechanical heart valve replacement. Methods 186 patients after mechanical heart valve replacement from June 2012 to June 2014 in our hospital were selected as the research object,the echocardiography data was ana-lyzed,the mechanical valve function of different replacement times,different types in aortic valve replacement and mitral valve replacement patients was compared according to the mechanical valve. Results The Pmax and MGP in the 10-15 years group was higher than that in the 5-10 years group and less than 5 years group,with significant difference (P<0.05). The EOA of each time point of different types of aortic mechanical valve was compared,with statistical differ-ence(P<0.05).The PR,MR,PG,MGP in the 5-10 years group was higher than that in less than 5 years group,with signifi-cant difference (P<0.05).The PR,MR,PG,MGP in the 10-15 years group was higher than that in the 5-10 years group, with significant difference (P<0.05). Conclusion Echocardiographic evaluation can reflect the recessionary situation of mechanical prosthetic valve function,the mechanical valve function in the aortic valve and mitral valve replacement in 5-10 years is gradually declined,so patients should be given regular echocardiographic assessment.%目的:探讨超声心动图评价心脏机械瓣膜置换术后瓣叶功能的长期变化趋势。方法选取2012年6月~2014年6月本院收治的186例心脏机械瓣置换术后患者作为研究对象,分析其超声心动图检查资料,根据置换时间、机械瓣类型等因素比较主动脉瓣置换与二尖瓣置换患者不同置换时间、不同型号的机械瓣功能。结果10~15年组的Pmax、MGP显著高于5~10年组和<5年组,差异有统计学意义(P<0.05)。各时间点不同类型主动脉瓣位机械瓣间EOA比较,差异有统计学意义(P<0.05)。5~10

  4. Valor de la grasaepicárdica en el diagnóstico de aterosclerosiscoronariaprevio a cirugíavalvular/ Significance of epicardial fat in the diagnosis of coronary atherosclerosis before heart valve surgery

    OpenAIRE

    2015-01-01

    Introduction: Epicardial fat has been shown to be related not only with clinical atherosclerosis, but also with subclinical atherosclerosis. Objective: To determine the significance of epicardial fat in the diagnosis of coronary atherosclerosis in patients with valvular heart disease. Method: The study included 62 patients scheduled for valve replacement surgery who had previously undergone invasive coronary angiography. Before surgery, epicardial fat measurement was performed by echo...

  5. Detergent decellularization of heart valves for tissue engineering: toxicological effects of residual detergents on human endothelial cells.

    Science.gov (United States)

    Cebotari, Serghei; Tudorache, Igor; Jaekel, Thomas; Hilfiker, Andres; Dorfman, Suzanne; Ternes, Waldemar; Haverich, Axel; Lichtenberg, Artur

    2010-03-01

    Detergents are powerful agents for tissue decellularization. Despite this, the high toxicity of detergent residua can be a major limitation. This study evaluated the efficacy of detergent removal from decellularized pulmonary valves (PVs) and the consequences of repopulation with human endothelial cells (HECs). Porcine PVs were treated with 1% sodium deoxycholate (SDC), group A; 1% sodium dodecyl sulfate (SDS), group B; and a mixture of 0.5% SDC/0.5% SDS, group C (n = 5 each). After each of 10 succeeding wash cycles (WCs), samples of the washing solution (WS) were analyzed by solid phase extraction and high performance liquid chromatography for the presence of detergents. Metabolic activity of HEC was also assessed in the WS samples (cytotoxicity and MTS assays). Decellularized and washed PVs were reseeded with HEC. Histological analysis demonstrated efficient tissue decellularization in all groups. Detergents' concentration in all WSs decreased exponentially and was below 50 mg/L after 6, 8, and 4 WCs in groups A, B, and C, respectively. This concentration resulted in no significant toxic influence on cell cultures, and scaffolds could be efficiently reseeded with HEC. In conclusion, intensive washing of detergent decellularized valvular scaffolds lowers the residual contamination below a hazardous threshold and allows their successful repopulation with HEC for tissue engineering purposes.

  6. Optimal C-arm angulation during transcatheter aortic valve replacement: Accuracy of a rotational C-arm computed tomography based three dimensional heart model.

    Science.gov (United States)

    Veulemans, Verena; Mollus, Sabine; Saalbach, Axel; Pietsch, Max; Hellhammer, Katharina; Zeus, Tobias; Westenfeld, Ralf; Weese, Jürgen; Kelm, Malte; Balzer, Jan

    2016-10-26

    To investigate the accuracy of a rotational C-arm CT-based 3D heart model to predict an optimal C-arm configuration during transcatheter aortic valve replacement (TAVR). Rotational C-arm CT (RCT) under rapid ventricular pacing was performed in 57 consecutive patients with severe aortic stenosis as part of the pre-procedural cardiac catheterization. With prototype software each RCT data set was segmented using a 3D heart model. From that the line of perpendicularity curve was obtained that generates a perpendicular view of the aortic annulus according to the right-cusp rule. To evaluate the accuracy of a model-based overlay we compared model- and expert-derived aortic root diameters. For all 57 patients in the RCT cohort diameter measurements were obtained from two independent operators and were compared to the model-based measurements. The inter-observer variability was measured to be in the range of 0°-12.96° of angular C-arm displacement for two independent operators. The model-to-operator agreement was 0°-13.82°. The model-based and expert measurements of aortic root diameters evaluated at the aortic annulus (r = 0.79, P r = 0.93, P r = 0.92, P < 0.01) correlated on a high level and the Bland-Altman analysis showed good agreement. The interobserver measurements did not show a significant bias. Automatic segmentation of the aortic root using an anatomical model can accurately predict an optimal C-arm configuration, potentially simplifying current clinical workflows before and during TAVR.

  7. Aortic valve surgery - minimally invasive

    Science.gov (United States)

    ... Saunders; 2012:chap 61. Otto CM, Bonow RO. Valvular heart disease. In: Mann DL, Zipes DP, Libby P, Bonow ... A.M. Editorial team. Related MedlinePlus Health Topics Heart Valve Diseases Browse the Encyclopedia A.D.A.M., Inc. ...

  8. 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.

  9. 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.

  10. 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.

  11. Surface engineering of artificial heart valve disks using nanostructured thin films deposited by chemical vapour deposition and sol-gel methods.

    Science.gov (United States)

    Jackson, M J; Robinson, G M; Ali, N; Kousar, Y; Mei, S; Gracio, J; Taylor, H; Ahmed, W

    2006-01-01

    Pyrolytic carbon (PyC) is widely used in manufacturing commercial artificial heart valve disks (HVD). Although PyC is commonly used in HVD, it is not the best material for this application since its blood compatibility is not ideal for prolonged clinical use. As a result thrombosis often occurs and the patients are required to take anti-coagulation drugs on a regular basis in order to minimize the formation of thrombosis. However, anti-coagulation therapy gives rise to some detrimental side effects in patients. Therefore, it is extremely urgent that newer and more technically advanced materials with better surface and bulk properties are developed. In this paper, we report the mechanical properties of PyC-HVD, i.e. strength, wear resistance and coefficient of friction. The strength of the material was assessed using Brinell indentation tests. Furthermore, wear resistance and coefficient of friction values were obtained from pin-on-disk testing. The micro-structural properties of PyC were characterized using XRD, Raman spectroscopy and SEM analysis. Also in this paper we report the preparation of freestanding nanocrystalline diamond films (FSND) using the time-modulated chemical vapour deposition (TMCVD) process. Furthermore, the sol-gel technique was used to uniformly coat PyC-HVD with dense, nanocrystalline-titanium oxide (nc-TiO2) coatings. The as-grown nc-TiO2 coatings were characterized for microstructure using SEM and XRD analysis.

  12. Indentation hardness: A simple test that correlates with the dissipated-energy predictor for fatigue-life in bovine pericardium membranes for bioprosthetic heart valves.

    Science.gov (United States)

    Tobaruela, Almudena; Rojo, Francisco Javier; García Paez, José María; Bourges, Jean Yves; Herrero, Eduardo Jorge; Millán, Isabel; Alvarez, Lourdes; Cordon, Ángeles; Guinea, Gustavo V

    2016-08-01

    The aim of this study was to evaluate the variation of hardness with fatigue in calf pericardium, a biomaterial commonly used in bioprosthetic heart valves, and its relationship with the energy dissipated during the first fatigue cycle that has been shown to be a predictor of fatigue-life (García Páez et al., 2006, 2007; Rojo et al., 2010). Fatigue tests were performed in vitro on 24 pericardium specimens cut in a root-to-apex direction. The specimens were subjected to a maximum stress of 1MPa in blocks of 10, 25, 50, 100, 250, 500, 1000 and 1500 cycles. By means of a modified Shore A hardness test procedure, the hardness of the specimen was measured before and after fatigue tests. Results showed a significant correlation of such hardness with fatigue performance and with the energy dissipated in the first cycle of fatigue, a predictor of pericardium durability. The study showed indentation hardness as a simple and reliable indicator of mechanical performance, one which could be easily implemented in improving tissue selection.

  13. The Analysis of Fetal Heart Valve Regurgitation among Fetuses without Intracardiac Defect%心内结构无异常胎儿的心脏瓣膜返流超声检查分析

    Institute of Scientific and Technical Information of China (English)

    仉晓红; 宫玉玲; 王海燕; 孙洪军; 刘传玺

    2012-01-01

    Objective Observing the situation of fetal heart valve regurgitation, to analysis the differences and causes in different gestational weeks. Methods Summarizing 296 fetal hearts which were screened in our department, except those with intracardiac defect and arterial duct contraction or advanced closure, to analysis the differences of detection ratio of different fetal valves regurgitation in different gestational weeks. Results Among fetuses of 20~24 gestational weeks, the detection ratio of tricuspid valve regurgitation was 10%, one was moderate, the rest were mild. The detection ratio of pulmonary valve regurgitation was 3.4%, all were mild. None of mitral valve and aortic valve regurgitation was detected. Among fetuses of 25-29 gestational weeks, the detection ratio of tricuspid valve regurgitation was 53.36%, 18 cases were moderate regurgitation. The detection ratio of mitral valve regurgitation was 7.92%, pulmonary valve regurgitation 7.03%, aortic valve regurgitation 0.014%, which all the degree of regurgitation was mild. Among fetuses of 30~34 gestational weeks, the detection ratio of tricuspid valve regurgitation was 59%, 4 cases were moderate. The detection ratio of mitral valve regurgitation was 13%, pulmonary valve regurgitation 14%, which all the degree of regurgitation was mild. None of aortic valve regurgitation was detected in this group. Among fetuses of 35-38 gestational weeks, the detection ratio of trieuspid valve regurgitation was 58.79%, with all were mild. The detection ratio of mitral valve regurgitation was 0.17%, pulmonary valve regurgitation 0.07%, which all the degree of regurgitation was mild. None of aortic valve regurgitation was detected in this group. Conclusions The detection of valve regurgitaion among fetuses without intracardiac defect is common. The tricuspid valve regurgitation has the highest detection ratio. The detection ratio of valve regurgitation is closely related to gestational weeks.%目的 观察心内结构无

  14. Time to achieving therapeutic international normalized ratio increases hospital length of stay after heart valve replacement surgery.

    Science.gov (United States)

    Arendt, Christopher J; Hong, Joon Hwa; Daly, Richard C; Scott, Christopher; Mehta, Ramila A; Bailey, Kent; Pathak, Jyotishman; Pereira, Naveen L

    2017-05-01

    Achieving a therapeutic international normalized ratio (INR) before hospital discharge is an important inpatient goal for patients undergoing mechanical cardiac valve replacement (MCVR). The use of clinical algorithms has reduced the time to achieve therapeutic INR (TTI) with warfarin therapy. Whether TTI prolongs length of stay (LOS) is unknown. Patients who underwent MCVR over a consecutive 42-month period were included. Clinical data were obtained from the Society of Thoracic Surgeons Adult Cardiac Surgery database and electronic medical records. Therapeutic INR was defined as per standard guidelines. Warfarin dose was prescribed using an inpatient pharmacy-managed algorithm and computer-based dosing tool. International normalized ratio trajectory, procedural needs, and drug interactions were included in warfarin dose determination. There were 708 patients who underwent MCVR, of which 159 were excluded for reasons that would preclude or interrupt warfarin use. Among the remainder of 549 patients, the average LOS was 6.4days and mean TTI was 3.5days. Landmark analysis showed that subjects in hospital on day 4 (n=542) who achieved therapeutic INR were more likely to be discharged by day 6 compared with those who did not achieve therapeutic INR (75% vs 59%, P<.001). Multivariable proportional hazards regression with TTI as a time-dependent effect showed a strong association with discharge (P=.0096, hazard ratio1.3) after adjustment for other significant clinical covariates. Time to achieve therapeutic INR is an independent predictor of LOS in patients requiring anticoagulation with warfarin after MCVR surgery. Alternative dosing and anticoagulation strategies will need to be adopted to reduce LOS in these patients. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Mitral Valve Prolapse in Pregnancy

    Directory of Open Access Journals (Sweden)

    Shi-Min Yuan

    Full Text Available Abstract Mitral valve prolapse is a benign condition. Mitral regurgitation is only complicated in patients with severe mitral valve prolapse. Women with mitral valve prolapse in the absence of other cardiovascular disorders tolerate pregnancy well and do not develop remarkable cardiac complications. Nevertheless, serious complications of mitral valve prolapse, including arrhythmia, infective endocarditis and cerebral ischemic events, can be present in pregnancy. Debates remain with regard to the use of prophylactic antibiotics and β-blockers in the pregnant women with mitral valve prolapse. The prognosis of the pregnant patients might be closely related to the pathological and (or functional changes of the mitral valve. Non-myxomatous mitral valve prolapse poses no or little obstetric risks in terms of pregnancy, labor and neonatal complications; whereas myxomatous mitral valve prolapse is a major etiology of valvular heart disease in women of childbearing age. In the pregnant patients with mitral valve prolapse progressing into major complications, surgical interventions are considered. Medicinal treatment of such patients with β-blockers should be a concern for the fetal safety.

  16. 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

  17. Transcatheter Aortic Valve Replacement in a Patient With a Previous Bioprosthetic Mitral Valve Replacement: Report of a Delayed Fatal Interaction.

    Science.gov (United States)

    Poulin, Frédéric; Lamarche, Yoan; Le, Van Hoai Viet; Doucet, Michel; Roméo, Philippe; Généreux, Philippe

    2016-02-01

    We report on a man with bioprosthetic mitral valve perforation who presented late after transcatheter aortic valve replacement with a balloon-expandable transcatheter heart valve (THV). The protrusion of the commissural strut of the bioprosthetic mitral valve coupled with the low implanted THV resulted in repetitive trauma leading to rupture of a mitral leaflet. Potential preventive strategies are discussed. This case illustrates the importance of preprocedural imaging screening and cautious THV deployment in patients with a bioprosthetic mitral valve.

  18. Re-operation of tricuspid regurgitation after mitral valve replacement with rheumatic heart disease%风湿性心脏病二尖瓣置换术后三尖瓣返流的再手术治疗

    Institute of Scientific and Technical Information of China (English)

    罗又桥; 方海宁; 谭伟; 李树松; 曹辉庆; 赖纪昌

    2014-01-01

    Objective To analyze clinical manifestation and investigate therapy effect of re-operation of tricuspid regurgitation (TR) after mitral valve replacement with rheumatic heart disease.Methods Seventeen cases with rheumatic heart disease recurred TR after mitral valve replacement surgery,underwent tricuspid valve surgery again in the Third People's Hospital of Nanchang from January 2000 to December 2011.Of 17 cases,10cases underwent tricuspid valve annuloplasty including 1 case for pure De Vega plasty,9 cases for the valve leaflets forming + artificial valve ring forming.Another 7 cases underwent tricuspid valve replacement surgery including 4 cases for biological valve replacement and 3 cases for mechanical valve.Retrospective analyzed the clinical manifestations,treatment process and condition of prognosis.Results One case was with early postoperative deaths (5.88%,1717),and died of postoperative left ventricular failure.Three cases were postoperative low cardiac output syndrome,2 cases were renal insufficiency,and 2 cases were respiratory insufficiency,all those cases were successfully cured.Sixteen cases were followed up from 3 months to 9 years and 2 cases were lost.Of 14,2 cases were NYHA class Ⅰ,8 cases for grade Ⅱ,4 cases for grade Ⅲ.Conclusion After mitral valve replacement in patients with rheumatic heart disease,TR in patients with reoperation is a suitable choice.Reasonable surgical indications,timing of surgery and good perioperative management are the keys to improve the success rate of surgery.%目的 分析风湿性心脏病二尖瓣置换术后再发三尖瓣返流(TR)患者的临床特点、外科手术方法和疗效,总结围手术期处理经验.方法 2000年1月至2011年12月,17例风湿性心脏病二尖瓣置换术后再发三尖瓣返流的患者在我院接受单纯再次三尖瓣手术,行三尖瓣成形术10例,包括单纯DeVega成形术1例、瓣叶成形+人工瓣环成形9例;行三尖瓣置换术7例,其中置换生物瓣4

  19. 心脏瓣膜置换术后围术期并发症的多因素分析%The Multivariate Analysis of the Perioperative Complications about the Patients with Heart Valve Replacement

    Institute of Scientific and Technical Information of China (English)

    吴小永; 李全民; 张满堂

    2013-01-01

      目的探讨手术前情况、手术方式及围手术期处理等对心脏瓣膜置换手术后围术期并发症的影响.方法收集216例行心脏瓣膜置换术患者的病历资料,详细统计围术期发生的并发症,对术前及围术期可能与并发症有关的相关因素进行统计学分析.结果①216例瓣膜置换手术中,二尖瓣和主动脉瓣双瓣置换术围术期并发症发生率明显高于二尖瓣置换组和主动脉瓣置换组.②Logistic回归分析结果显示:二尖瓣与主动脉瓣联合置换,术前心功能Ⅳ级,术中心脏阻断时间≥110min,体外循环时间≥150min,术后呼吸机支持时间过长≥24h等是影响心脏瓣膜置换术患者围手术期并发症的危险因素.结论双瓣膜置换术,术前心功能差,术中阻断主动脉时间过长,体外循环时间过长,术后呼吸机支持时间过长等是影响心脏瓣膜置换术后围术期并发症的危险因素.%Objective To study the effects of preoperative condition, operative methods and perioperative management on the complications of the patients with heart valve replacement in perioperative period.Methods To collect the 216 cases data of the patient with heart val