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

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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.

Design and efficacy of a single-use bioreactor for heart valve tissue engineering.

Science.gov (United States)

Converse, Gabriel L; Buse, Eric E; Neill, Kari R; McFall, Christopher R; Lewis, Holley N; VeDepo, Mitchell C; Quinn, Rachael W; Hopkins, Richard A

2017-02-01

Heart valve tissue engineering offers the promise of improved treatments for congenital heart disorders; however, widespread clinical availability of a tissue engineered heart valve (TEHV) has been hindered by scientific and regulatory concerns, including the lack of a disposable, bioreactor system for nondestructive valve seeding and mechanical conditioning. Here we report the design for manufacture and the production of full scale, functional prototypes of such a system. To evaluate the efficacy of this bioreactor as a tool for seeding, ovine aortic valves were decellularized and subjected to seeding with human mesenchymal stem cells (hMSC). The effects of pulsatile conditioning using cyclic waveforms tuned to various negative and positive chamber pressures were evaluated, with respect to the seeding of cells on the decellularized leaflet and the infiltration of seeded cells into the interstitium of the leaflet. Infiltration of hMSCs into the aortic valve leaflet was observed following 72 h of conditioning under negative chamber pressure. Additional conditioning under positive pressure improved cellular infiltration, while retaining gene expression within the MSC-valve interstitial cell phenotype lineage. This protocol resulted in a subsurface pilot population of cells, not full tissue recellularization. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 249-259, 2017. © 2015 Wiley Periodicals, Inc.

Leaflet escape in a new bileaflet mechanical valve: TRI technologies.

Science.gov (United States)

Bottio, Tomaso; Casarotto, Dino; Thiene, Gaetano; Caprili, Luca; Angelini, Annalisa; Gerosa, Gino

2003-05-13

Leaflet escape is a mode of structural valve failure for mechanical prostheses. This complication previously has been reported for both monoleaflet and bileaflet valve models. We report 2 leaflet escape occurrences observed in 2 patients who underwent valve replacement with a TRI Technologies valve prosthesis. At the University of Padua, between November 2000 and February 2002, 36 TRI Technologies valve prostheses (26 aortic and 10 mitral) were implanted in 34 patients (12 women and 22 men) with a mean age of 59.9+/-10.3 years (range, 30 to 75 years). There were 5 deaths: 3 in hospital, 1 early after discharge, and 1 late. Two patients experienced a catastrophic prosthetic leaflet escape; the first patient was a 52-year-old man who died 10 days after aortic valve and ascending aorta replacement, and the second was a 58-year-old man who underwent a successful emergency reoperation 20 months after mitral valve replacement. Examination of the explanted prostheses showed in both cases a leaflet escape caused by a leaflet's pivoting system fracture. Prophylactic replacement was then successfully accomplished so far in 12 patients, without evidence of structural valve failure in any of them. Among other significant postoperative complications, we observed 3 major thromboembolisms, 1 hemorrhage, and 1 paravalvular leak. These catastrophes prompted us to interrupt the implantation program, and they cast a shadow on the durability of the TRI Technologies valve prosthesis because of its high risk of structural failure.

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.

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

Effect of the Mitral Valve's Anterior Leaflet on Axisymmetry of Transmitral Vortex Ring.

Science.gov (United States)

Falahatpisheh, Ahmad; Pahlevan, Niema M; Kheradvar, Arash

2015-10-01

The shape and formation of transmitral vortex ring are shown to be associated with diastolic function of the left ventricle (LV). Transmitral vortex ring is a flow feature that is observed to be non-axisymmetric in a healthy heart and its inherent asymmetry in the LV assists in efficient ejection of the blood during systole. This study is a first step towards understanding the effects of the mitral valve's anterior leaflet on transmitral flow. We experimentally study a single-leaflet model of the mitral valve to investigate the effect of the anterior leaflet on the axisymmetry of the generated vortex ring based on the three-dimensional data acquired using defocusing digital particle image velocimetry. Vortex rings form downstream of a D-shaped orifice in presence or absence of the anterior leaflet in various physiological stroke ratios. The results of the statistical analysis indicate that the formed vortex ring downstream of a D-shaped orifice is markedly non-axisymmetric, and presence of the anterior leaflet improves the ring's axisymmetry. This study suggests that the improvement of axisymmetry in presence of the anterior leaflet might be due to coupled dynamic interaction between rolling-up of the shear layer at the edges of the D-shaped orifice and the borders of the anterior leaflet. This interaction can reduce the non-uniformity in vorticity generation, which results in more axisymmetric behavior compared to the D-shaped orifice without the anterior leaflet.

Restoration of Tricuspid Valve Mechanism at the Level of Displaced Septal and Posterior Leaflets in Ebstein's Anomaly.

Science.gov (United States)

Im, Yu-Mi; Park, Chun Soo; Park, Jeong-Jun; Yun, Tae-Jin

2016-03-01

Surgical techniques currently used for the repair of Ebstein's anomaly comprise reconstruction of the tricuspid valve mechanism at the level of the true annulus with or without plication of the atrialized right ventricle. However, performing this procedure for patients with a dysmorphic anterior leaflet (i.e., insufficient leaflet tissue and decreased mobility due to tethering) may necessitate technical modifications. A retrospective review was performed of 31 patients (seven males and 24 females, median age at operation 31 years) with Ebstein's anomaly, who underwent tricuspid valve repair between March 2002 and December 2014. The original Hetzer technique (annulus to annulus approximation) was employed for six patients with a well-formed anterior leaflet. In 25 patients, the tricuspid valve mechanism was restored at the displaced septal leaflet by approximating the anterior leaflet attachment in the true annulus to the displaced septal leaflet attachment in the mid-septum. A bidirectional superior cavopulmonary anastomosis was added in 27 of 31 (87%) patients. No early or late death occurred during the median follow-up of 66 months (1-138 months). Immediate postoperative tricuspid regurgitation was trivial to mild in 22 patients, and the median preoperative, immediate postoperative, and last follow-up tricuspid regurgitation jet areas in 21 adult patients were 23.3 cm2, 10.4 cm2, and 7.0 cm2, respectively. Two patients underwent reoperation at 81 and 119 months postoperatively. Five-year freedom from severe tricuspid regurgitation or reoperation was 93.2%. Restoration of the tricuspid valve mechanism at the level of displaced septal leaflet leads to excellent long-term outcomes. The addition of the bidirectional superior cavopulmonary anastomosis has contributed to the success of this technique. © 2016 Wiley Periodicals, Inc.

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.

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

Science.gov (United States)

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

2006-11-01

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

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.

Mitral valve stenosis caused by abnormal pannus extension over the prosthetic ring and leaflets after Duran ring mitral annuloplasty.

Science.gov (United States)

Yunoki, Junji; Minato, Naoki; Katayama, Yuji; Sato, Hisashi

2009-01-01

We treated a 61-year-old woman with mitral stenosis caused by pannus formation after Duran ring annuloplasty. Pannus overgrowth on the ring with extension onto both leaflets narrowed the mitral orifice and severely restricted the mobility of the valve leaflets. Mitral valve replacement with a St. Jude Medical mechanical heart valve prosthesis was successfully performed, and the postoperative course was uneventful. Patients undergoing Duran ring annuloplasty should be followed up with the consideration of possible mitral stenosis caused by pannus extension, as the cause for pannus formation remains unclear.

Randomised trial of mitral valve repair with leaflet resection versus leaflet preservation on functional mitral stenosis (The CAMRA CardioLink-2 Trial).

Science.gov (United States)

Chan, Vincent; Chu, Michael W A; Leong-Poi, Howard; Latter, David A; Hall, Judith; Thorpe, Kevin E; de Varennes, Benoit E; Quan, Adrian; Tsang, Wendy; Dhingra, Natasha; Yared, Kibar; Teoh, Hwee; Chu, F Victor; Chan, Kwan-Leung; Mesana, Thierry G; Connelly, Kim A; Ruel, Marc; Jüni, Peter; Mazer, C David; Verma, Subodh

2017-05-30

The gold-standard treatment of severe mitral regurgitation (MR) due to degenerative disease is valve repair, which is surgically performed with either a leaflet resection or leaflet preservation approach. Recent data suggest that functional mitral stenosis (MS) may occur following valve repair using a leaflet resection strategy, which adversely affects patient prognosis. A randomised comparison of these two approaches to mitral repair on functional MS has not been conducted. This is a prospective, multicentre randomised controlled trial designed to test the hypothesis that leaflet preservation leads to better preservation of mitral valve geometry, and therefore, will be superior to leaflet resection for the primary outcome of functional MS as assessed by 12-month mean mitral valve gradient at peak exercise. Eighty-eight patients with posterior leaflet prolapse will be randomised intraoperatively once deemed by the operating surgeon to feasibly undergo mitral repair using either a leaflet resection or leaflet preservation approach. Secondary end points include comparison of repair strategies with regard to mitral valve orifice area, leaflet coaptation height, 6 min walk test and a composite major adverse event end point consisting of recurrent MR ≥2+, death or hospital readmission for congestive heart failure within 12 months of surgery. Institutional ethics approval has been obtained from all enrolling sites. Overall, there remains clinical equipoise regarding the mitral valve repair strategy that is associated with the least likelihood of functional MS. This trial hopes to introduce high-quality evidence to help surgical decision making in this context. NCT02552771. © 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.

Morphological and mechanical properties of the posterior leaflet chordae tendineae in the mitral valve

NARCIS (Netherlands)

Lodder, J.; Verkerke, Gijsbertus Jacob; Delemarre, B.J.M.; Dodou, D.

2016-01-01

A number of studies have investigated the morphological and mechanical properties of the chordae tendineae of the mitral valve, providing comparisons between basal, marginal, and strut chordae and between chordae at the anterior and posterior leaflets. This study contributes to the literature by

Morphological and mechanical properties of the posterior leaflet chordae tendineae in the mitral valve

NARCIS (Netherlands)

Lodder, Joost; Verkerke, Gijsbertus J.; Delemarre, Ben J. M.; Dodou, Dimitra

A number of studies have investigated the morphological and mechanical properties of the chordae tendineae of the mitral valve, providing comparisons between basal, marginal, and strut chordae and between chordae at the anterior and posterior leaflets. This study contributes to the literature by

A study of the pulsatile flow and its interaction with rectangular leaflets

Science.gov (United States)

Ledesma, Rene; Zenit, Roberto; Pulos, Guillermo

2009-11-01

To avoid the complexity and limited understanding of the 3D pulsatile flow field through heart valves, a cardiac-like flow circuit and a test channel were designed to study the behavior of bidimensional leaflets made of hyperelastic materials. We study a simple 2D arrangement to understand the basic physics of the flow-leaflet interaction. Creating a periodic pressure gradient, measurements of leaflet deflection were obtained for different flow conditions, geometries and materials. Using PIV and Phase Locking techniques, we have obtained the leaflet motion and the time-dependent flow velocity fields. The results show that two dimensionless parameters determine the performance of a simple bi-dimensional valve, in accordance with the flow conditions applied: π1=f(sw)^1/2(E/ρ)^1/2 and π2=V/(2slw), where f is the pulsation frequency, V is the stroke volume, s, w and l are the dimensions on the leaftlet and E and ρ are the elastic modulus and density of the material, respectively. Furthermore, we have identified the conditions for which the fluid stresses can be minimized. With these results we propose a new set of parameters to improve the performance of prosthetic heart valves and, in consequence, to reduce blood damage.

Activation delay-induced mechanical dyssynchrony in single-ventricle heart disease

DEFF Research Database (Denmark)

Forsha, Daniel; Risum, Niels; Barker, Piers

2017-01-01

We present the case of an infant with a single functional ventricle who developed ventricular dysfunction and heart failure due to an electrical activation delay and dyssynchrony. Earlier recognition of this potentially reversible aetiology may have changed her poor outcome.......We present the case of an infant with a single functional ventricle who developed ventricular dysfunction and heart failure due to an electrical activation delay and dyssynchrony. Earlier recognition of this potentially reversible aetiology may have changed her poor outcome....

Subclinical leaflet thrombosis in surgical and transcatheter bioprosthetic aortic valves

DEFF Research Database (Denmark)

Chakravarty, Tarun; Søndergaard, Lars; Friedman, John

2017-01-01

rates of transient ischaemic attacks (TIAs; 4·18 TIAs per 100 person-years vs 0·60 TIAs per 100 person-years; p=0·0005) and all strokes or TIAs (7·85 vs 2·36 per 100 person-years; p=0·001). INTERPRETATION: Subclinical leaflet thrombosis occurred frequently in bioprosthetic aortic valves, more commonly...... outcomes after TAVR with the new-generation valves, prevention and treatment of subclinical leaflet thrombosis might offer a potential opportunity for further improvement in valve haemodynamics and clinical outcomes. FUNDING: RESOLVE (Cedars-Sinai Heart Institute) and SAVORY (Rigshospitalet)....

Lipid diffusion in the distal and proximal leaflets of supported lipid bilayer membranes studied by single particle tracking

Science.gov (United States)

Schoch, Rafael L.; Barel, Itay; Brown, Frank L. H.; Haran, Gilad

2018-03-01

Supported lipid bilayers (SLBs) have been studied extensively as simple but powerful models for cellular membranes. Yet, potential differences in the dynamics of the two leaflets of a SLB remain poorly understood. Here, using single particle tracking, we obtain a detailed picture of bilayer dynamics. We observe two clearly separate diffusing populations, fast and slow, that we associate with motion in the distal and proximal leaflets of the SLB, respectively, based on fluorescence quenching experiments. We estimate diffusion coefficients using standard techniques as well as a new method based on the blur of images due to motion. Fitting the observed diffusion coefficients to a two-leaflet membrane hydrodynamic model allows for the simultaneous determination of the intermonolayer friction coefficient and the substrate-membrane friction coefficient, without any prior assumptions on the strengths of the relevant interactions. Remarkably, our calculations suggest that the viscosity of the interfacial water confined between the membrane and the substrate is elevated by ˜104 as compared to bulk water. Using hidden Markov model analysis, we then obtain insight into the transbilayer movement of lipids. We find that lipid flip-flop dynamics are very fast, with half times in the range of seconds. Importantly, we find little evidence for membrane defect mediated lipid flip-flop for SLBs at temperatures well above the solid-to-liquid transition, though defects seem to be involved when the SLBs are cooled down. Our work thus shows that the combination of single particle tracking and advanced hydrodynamic modeling provides a powerful means to obtain insight into membrane dynamics.

Numerical investigation of the performance of three hinge designs of bileaflet mechanical heart valves.

Science.gov (United States)

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

2010-11-01

Thromboembolic complications (TECs) of bileaflet mechanical heart valves (BMHVs) are believed to be due to the nonphysiologic mechanical stresses imposed on blood elements by the hinge flows. Relating hinge flow features to design features is, therefore, essential to ultimately design BMHVs with lower TEC rates. This study aims at simulating the pulsatile three-dimensional hinge flows of three BMHVs and estimating the TEC potential associated with each hinge design. Hinge geometries are constructed from micro-computed tomography scans of BMHVs. Simulations are conducted using a Cartesian sharp-interface immersed-boundary methodology combined with a second-order accurate fractional-step method. Leaflet motion and flow boundary conditions are extracted from fluid-structure-interaction simulations of BMHV bulk flow. The numerical results are analyzed using a particle-tracking approach coupled with existing blood damage models. The gap width and, more importantly, the shape of the recess and leaflet are found to impact the flow distribution and TEC potential. Smooth, streamlined surfaces appear to be more favorable than sharp corners or sudden shape transitions. The developed framework will enable pragmatic and cost-efficient preclinical evaluation of BMHV prototypes prior to valve manufacturing. Application to a wide range of hinges with varying design parameters will eventually help in determining the optimal hinge design.

The Impact of Fluid Inertia on In Vivo Estimation of Mitral Valve Leaflet Constitutive Properties and Mechanics.

Science.gov (United States)

Bark, David L; Dasi, Lakshmi P

2016-05-01

We examine the influence of the added mass effect (fluid inertia) on mitral valve leaflet stress during isovolumetric phases. To study this effect, oscillating flow is applied to a flexible membrane at various frequencies to control inertia. Resulting membrane strain is calculated through a three-dimensional reconstruction of markers from stereo images. To investigate the effect in vivo, the analysis is repeated on a published dataset for an ovine mitral valve (Journal of Biomechanics 42(16): 2697-2701). The membrane experiment demonstrates that the relationship between pressure and strain must be corrected with a fluid inertia term if the ratio of inertia to pressure differential approaches 1. In the mitral valve, this ratio reaches 0.7 during isovolumetric contraction for an acceleration of 6 m/s(2). Acceleration is reduced by 72% during isovolumetric relaxation. Fluid acceleration also varies along the leaflet during isovolumetric phases, resulting in spatial variations in stress. These results demonstrate that fluid inertia may be the source of the temporally and spatially varying stiffness measurements previously seen through inverse finite element analysis of in vivo data during isovolumetric phases. This study demonstrates that there is a need to account for added mass effects when analyzing in vivo constitutive relationships of heart valves.

A new self-expandable aortic valved stent deployed above native leaflets for aortic insufficiency: an in vitro study.

Science.gov (United States)

Huang, H; Zhou, Y; Shao, J; Cai, J; Mei, Y; Wang, Y

2012-12-01

The aim of this paper was to develop a new self-expandable aortic valved stent following the shape of the sinus of Valsalva, which can be deployed above native leaflets for aortic regurgitation, and study it's effect on coronary artery flow when orthotopic implantation in and above native leaflets. New self-expandable aortic valved stent consist of nitinol stent and bovine pericardium, and was designed following the shape of the sinus of Valsalva, the bovine pericardium was tailed as native leaflet. Thirty-six swine hearts were divided into three equal groups of twelve. In Group A (N.=12), the new self-expandable aortic valved stents deployed in native leaflets. In Group B (N.=12), the new self-expandable aortic valved stents deployed above native leaflets. In Group C (N.=12), the cylinder-like valved stents deployed only in native leaflets. The measurements of each coronary flow rate and endoscopic inspections were repeated post-implantation. In Group A and C, valve implantation in native leaflets resulted in a significant decrease in both left and right coronary flows. In Group B, no significant change in either right or left coronary flow was found after new self-expandable aortic valved stent placement. Endoscopic inspections showed that in group A and C the native leaflets sandwiched between valved stent and aortic wall, whereas, in group B the native leaflets were under the artificial leaflets. Two kinds of stents deployed in native leaflets affect left and right coronary flows significantly. No significant effect was found when the new self-expandable aortic valved stent deployed above native leaflets. This new self-expandable aortic valved stent can be deployed above the native leaflets, which avoids the obstruction of native leaflets on coronary flow.

[Evaluation of a self-care leaflet].

Science.gov (United States)

Lystad, N; Heian, F

1989-01-20

A self care leaflet of 50 pages was distributed in Tingvoll, a municipality with 3,500 inhabitants. The leaflet gives advice about self treatment and prevention of common health problems, and guidelines for contacting the health services. In surveys conducted just before and 10 months after the distribution, we documented -- how the leaflet was accepted and used --changes in knowledge about the health problems mentioned in the leaflet. The leaflet was well accepted. It was characterized as easy to read and to use. 10 months after distribution to read and to use. 10 months after distribution 90% found it within five minutes. 63% used the leaflet when they had a health problem. 90% of those using the leaflet felt more sure that they acted correctly after consulting it, and 60% changed their mind about consulting a general practitioner. We consider the level of knowledge about health problems to be low. The evaluation showed increased knowledge in all groups, except for persons "responsible for caring for elderly relatives". The increase was most marked for "men" and for "persons with health education".

The contribution of matrix and cells to leaflet retraction in heart valve tissue engineering

NARCIS (Netherlands)

Vlimmeren, van M.A.A.

2011-01-01

Heart valve tissue engineering is a promising technique to overcome the drawbacks of currently used mechanical and prosthetic heart valve replacements. Tissue engineered (TE) heart valves are viable and autologous implants that have the capacity to grow, remodel and repair throughout a patient’s

A novel polymeric prosthetic heart valve: design, manufacture, and testing

OpenAIRE

Brubert, Jacob

2016-01-01

In this thesis a flexible leaflet polymeric prosthetic aortic heart valve was designed, manufactured, and tested. The prosthesis was designed with the aim of overcoming the need for anticoagulant therapy, which is required for current mechanical prostheses; while also having lifelong durability, which current bioprosthetic heart valves are not able to achieve. Inspired by the anisotropic architecture of collagen in the natural valve, a shortlist of polystyrene based block copolymers (BCPs), w...

Patients’ views on electronic patient information leaflets

Directory of Open Access Journals (Sweden)

Hammar T

2016-06-01

Full Text Available Background: Information in society and in health care is currently undergoing a transition from paper to digital formats, and the main source of information will probably be electronic in the future. Objective: To explore patients’ use and perceptions of the patient information leaflet included in the medication package, and their attitude towards a transition to an electronic version. Methods: The data was collected during October to November 2014 among individuals in South-Eastern Sweden, using a questionnaire (n=406, response rate 78% and interviews (n=15. Results: The questionnaire showed that the majority of the respondents (52% occasionally read the patient information leaflet, 37% always read it, and 11% never read it. Almost half of the patients (41% were positive towards reading the patient information leaflet electronically while 32% were hesitant and 26% neutral. A majority of the patients would request to get the patient information leaflet printed at the pharmacy if it was not included in the package. There were differences in attitude related to age and gender. The interviews showed that patients had mixed views on a transition to an electronic patient information leaflet. The patients perceived several positive aspects with an electronic patient information leaflet but were concerned about elderly patients. Conclusion: Although many were positive towards reading the patient information leaflet electronically, the majority prefer the patient information leaflet in paper form. Providing appropriate and useful eHealth services for patients to access the patient information leaflet electronically, along with education, could prepare patients for a transition to electronic patient information leaflet.

Triple leaflet perforation due to endocarditis in aortic valve complicated by pneumonia and exacerbation of chronic obstructive pulmonary disease

Directory of Open Access Journals (Sweden)

Elton Soydan

2015-09-01

Full Text Available Valve perforation complicating infective endocarditis has been for decades a bad sign leading to severe valve destruction, intractable heart failure and even death if surgical therapy is not administered in time. Here we present a 57 years old male patient inadvertently diagnosed with pneumonia and chronic obstructive pulmonary disease exacerbation in another hospital. After 20 days of broad spectrum antibiotics and bronchodilator therapy no improvement was achieved. During examination a severe aortic regurgitation was recognized. Immediately after, patient was transferred to our hospital for aortic valve surgery evaluation. Transthorasic echocardiography (TTE showed a severe aortic regurgitation and vegetation like echogenicity over the noncoronary leaflet. An aortic valve replacement surgical therapy was decided. During the aortic valve excision underneath the vegetations, multiple small perforations in all the three leaflets were noticed. The destructed valve was excised and a mechanical aortic prosthesis (St Jude No: 23, MN, USA was successfully replaced. After 14 days of treatment patient was healthily discharged.

Mechanisms of mechanical heart valve cavitation: investigation using a tilting disk valve model.

Science.gov (United States)

He, Z; Xi, B; Zhu, K; Hwang, N H

2001-09-01

The induction of mechanical heart valve (MHV) cavitation was investigated using a 27 mm Medtronic Hall (MH27) tilting disk valve. The MH27 valve was mounted in the mitral position of a simulating pulse flow system, and stroboscopic lighting used to visualize cavitation bubbles on the occluder inflow surface at the instant of valve closure. MHV cavitation was monitored using a digital camera with 0.04 mm/pixel resolution sufficient to render the tiny bubbles clearly visible on the computer monitor screen. Cavitation on MH27 valve was classified as five types according to the time, site and shape of the cavitation bubbles. Valve cavitation occurred at the instant of occluder impact with the valve seat at closing. The impact motion was subdivided into three temporal phases: (i) squeezing flow; (ii) elastic collision; and (iii) leaflet rebound. MHV cavitation caused by vortices was found to be initiated by the squeezing jet and/or by the transvalvular leakage jets. By using a tension wave which swept across the occluder surface immediately upon elastic impact, nuclei in the vortex core were expanded to form cavitation bubbles. Analysis of the shape and location of the cavitation bubbles permitted a better understanding of MHV cavitation mechanisms, based on the fluid dynamics of jet vortex and tension wave propagations.

Consent information leaflets - readable or unreadable?

Science.gov (United States)

Graham, Caroline; Reynard, John M; Turney, Benjamin W

2015-05-01

The objective of this article is to assess the readability of leaflets about urological procedures provided by the British Association of Urological Surgeons (BAUS) to evaluate their suitability for providing information. Information leaflets were assessed using three measures of readability: Flesch Reading Ease, Flesch-Kincaid and Simple Measure of Gobbledygook (SMOG) grade formulae. The scores were compared with national literacy statistics. Relatively good readability was demonstrated using the Flesch Reading Ease (53.4-60.1) and Flesch-Kincaid Grade Level (6.5-7.6) methods. However, the average SMOG index (14.0-15.0) for each category suggests that the majority of the leaflets are written above the reading level of an 18-year-old. Using national literacy statistics, at least 43% of the population will have significant difficultly understanding the majority of these leaflets. The results suggest that comprehension of the leaflets provided by the BAUS is likely to be poor. These leaflets may be used as an adjunct to discussion but it is essential to ensure that all the information necessary to make an informed decision has been conveyed in a way that can be understood by the patient.

Prediction of the ischemic origin of functional mitral regurgitation in patients with systolic heart failure through posterior mitral leaflet angle

Directory of Open Access Journals (Sweden)

Fereshteh Ghaderi

2018-01-01

Full Text Available BACKGROUND: Differentiating ischemic from non-ischemic functional mitral regurgitation‎ (FMR in patients with cardiomyopathy is important in terms of the therapeutic decision-making and prognosis, but might be clinically challenging. In this study, the deformation of mitral valve (MV indices in the prediction of the etiology of FMR was assessed using 2D transthoracic and tissue Doppler echocardiography.METHODS: This case-control study was conducted from April 2015 to January 2016 in Imam Reza Hospital in Mashhad, Iran. The participants consisted of 40 patients with ischemic cardiomyopathy (ICM and 22 with non-ischemic dilated cardiomyopathy (DCM who referred to the heart failure clinic. Transthoracic echocardiography was performed using the conventional 2D and tissue Doppler imaging (TDI. MV tenting area (TA, coaptation distance (CD, anterior and posterior mitral leaflet angles (AMLA and PMLA, and regional systolic myocardial velocity (Sm were measured.RESULTS: There were no significant differences in echocardiographic indices between the two groups, besides Sm and PMLA which were significantly lower and higher, respectively, in ICM subjects in comparison with DCM patients (P = 0.002. PMLA ≥ 40 degrees and Sm ≤ 4 cm/second have a relatively high value for discriminating the ischemic from non-ischemic origin of functional MR in subjects with systolic heart failure (sensitivity: 80.0% and 70.0%, specificity: 73.0% and 77.3%; P = 0.001 and P < 0.001; respectively. Multivariable logistic regression identified PMLA and anterior Sm as major determinants for ischemic MR {Odds ratio (OR [95% confidence interval (CI] = 0.89 (0.82-0.96, P = 0.003, OR (95% CI = 0.29 (0.14-0.60, P = 0.001, respectively}.CONCLUSION: The present study showed that PMLA and Sm had an independent significant association with the mechanism of FMR. These findings are suggestive of the predictive role of mitral deformation echocardiographic indices in the determination of the

Document of the Month: German Propaganda Leaflets

Science.gov (United States)

Byers, CeCe; Alexander, Mary

1978-01-01

Excerpts from two propaganda leaflets distributed by Germany during World War I to demoralize American soldiers. Teaching suggestions encourage students to examine the leaflets' tone, guess who the authors might have been, and analyze the leaflets as examples of a propaganda technique. (AV)

Differentiation of thrombus from pannus as the cause of acquired mechanical prosthetic heart valve obstruction by non-invasive imaging: a review of the literature.

Science.gov (United States)

Tanis, Wilco; Habets, Jesse; van den Brink, Renee B A; Symersky, Petr; Budde, Ricardo P J; Chamuleau, Steven A J

2014-02-01

For acquired mechanical prosthetic heart valve (PHV) obstruction and suspicion on thrombosis, recently updated European Society of Cardiology guidelines advocate the confirmation of thrombus by transthoracic echocardiography, transesophageal echocardiography (TEE), and fluoroscopy. However, no evidence-based diagnostic algorithm is available for correct thrombus detection, although this is clinically important as fibrinolysis is contraindicated in non-thrombotic obstruction (isolated pannus). Here, we performed a review of the literature in order to propose a diagnostic algorithm. We performed a systematic search in Pubmed and Embase. Included publications were assessed on methodological quality based on the validated Quality Assessment of Diagnostic Accuracy Studies (QUADAS) II checklist. Studies were scarce (n = 15) and the majority were of moderate methodological quality. In total, 238 mechanical PHV's with acquired obstruction and a reliable reference standard were included for the evaluation of the role of fluoroscopy, echocardiography, or multidetector-row computed tomography (MDCT). In acquired PHV obstruction caused by thrombosis, mass detection by TEE and leaflet restriction detected by fluoroscopy were observed in the majority of cases (96 and 100%, respectively). In contrast, in acquired PHV obstruction free of thrombosis (pannus), leaflet restriction detected by fluoroscopy was absent in some cases (17%) and mass detection by TEE was absent in the majority of cases (66%). In case of mass detection by TEE, predictors for obstructive thrombus masses (compared with pannus masses) were leaflet restriction, soft echo density, and increased mass length. In situations of inconclusive echocardiography, MDCT may correctly detect pannus/thrombus based on the morphological aspects and localization. In acquired mechanical PHV obstruction without leaflet restriction and absent mass on TEE, obstructive PHV thrombosis cannot be confirmed and consequently, fibrinolysis

The readability and suitability of sexual health promotion leaflets.

Science.gov (United States)

Corcoran, Nova; Ahmad, Fatuma

2016-02-01

To investigate the readability and suitability of sexual health promotion leaflets. Application of SMOG, FRY and SAM tests to assess the readability and suitability of a selection of sexual health leaflets. SMOG and FRY scores illustrate an average reading level of grade 9. SAM scores indicate that 59% of leaflets are superior in design and 41% are average in design. Leaflets generally perform well in the categories of content, literacy demand, typography and layout. They perform poorly in use of graphics, learning stimulation/motivation and cultural appropriateness. Sexual health leaflets have a reading level that is too high. Leaflets perform well on the suitability scores indicating they are reasonably suitable. There are a number of areas where sexual health leaflets could improve their design. Numerous practical techniques are suggested for improving the readability and suitability of sexual health leaflets. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

[Micromorphology of pejibaye leaflets Bactris gasipaes (Arecaceae) var. diamonds-10].

Science.gov (United States)

Sánchez-Chacón, Ethel; Alvarado-Rodríguez, Olman; Rodríguez-Arrieta, Alexander; Gómez-Alpízar, Luis

2016-09-01

Bactris gasipaes is widely cultivated for the consumption of palm hearts and fruits. The present work describes the micro morphological characteristics of leaflets from adult plants of B. gasipaes, thornless variety Diamantes-10, collected in the Diamantes Experimental Station in Guápiles, Costa Rica. We collected 25 leaflets and analyses were performed with a combination of microscopy techniques: light microscopy, scanning electron microscopy and transmission electron microscopy to study their structure. Our results showed that leaflets have abundant epicuticular wax on adaxial and abaxial surfaces. Analyses from the epidermis indicated that it is composed of isodiametric cells, and it is also evident that hypodermis cells have rectangular shape and are larger than the other epidermal cells. We observed stomata on both surfaces, but they were more abundant in the abaxial surface. On the other hand, the epidermis showed the presence of trichomes with three different morphologies. In the parenchyma, cells are large and not well defined, and we observed the presence of astroesclereids, and compact groups of fiber bundles between parenchyma cells. The central vein has several vascular bundles, arranged in a continuous manner, and they are surrounded by sclerotic tissue; some of these fibers presented live protoplasts. All minor veins showed the same anatomy as the central vein. In these veins, the vessel elements of protoxylem and metaxylem showed scalariform ornaments on their walls. Phloem is located towards the adaxial surface of the vein and we observed sieve and companion cells surrounded by fibers and parenchyma cells. The companion cells presented branched plasmodesmata attached to a sieve element, and in these elements we found protein bodies called P-protein. The main anatomical difference in the leaflets of the var. Diamantes-10, compared to the other varieties of B. gasipaes K, is the lack of thorns; the other morphological features seem to be conserved.

Stress Analysis of Transcatheter Aortic Valve Leaflets Under Dynamic Loading: Effect of Reduced Tissue Thickness.

Science.gov (United States)

Abbasi, Mostafa; Azadani, Ali N

2017-07-01

In order to accommodate transcatheter valves to miniaturized catheters, the leaflet thickness must be reduced to a value which is typically less than that of surgical bioprostheses. The study aim was to use finite-element simulations to determine the impact of the thickness reduction on stress and strain distribution. A 23 mm transcatheter aortic valve (TAV) was modelled based on the Edwards SAPIEN XT (Edwards Lifesciences, Irvine, CA, USA). Finite-element (FE) analysis was performed using the ABAQUS/Explicit solver. An ensemble-averaged transvalvular pressure waveform measured from in-vitro tests conducted in a pulse duplicator was applied to the leaflets. Through a parametric study, uniform TAV leaflet thickness was reduced from 0.5 to 0.18 mm. By reducing leaflet thickness, significantly higher stress values were found in the leaflet's fixed edge during systole, and in the commissures during diastole. Through dynamic FE simulations, the highest stress values were found during systole in the leaflet fixed edge. In contrast, at the peak of diastole high-stress regions were mainly observed in the commissures. The peak stress was increased by 178% and 507% within the leaflets after reducing the thickness of 0.5 mm to 0.18 mm at the peak of systole and diastole, respectively. The study results indicated that, the smaller the leaflet thickness, the higher the maximum principal stress. Increased mechanical stress on TAV leaflets may lead to accelerated tissue degeneration. By using a thinner leaflet, TAV durability may not atch with that of surgical bioprostheses.

Promotion of family planning services in practice leaflets.

Science.gov (United States)

Marshall, M N; Gray, D J; Pearson, V; Phillips, D R; Owen, M

1994-10-08

Providing 75% of family planning services in the United Kingdom, general practitioners are required to produce leaflets which describe the contraceptive services they provide. The authors analyzed information about family planning provided to clients through practice leaflets. 88% of practice leaflets from the 198 practices in Devon were available from the Devon Family Health Services Authority for analysis. It was determined that the leaflets are not being best used to advertise the range and potential of family planning services. Although all practices in Devon offer contraceptive services, only 90% of leaflets mentioned that the services are available. Reference to postcoital contraception and information about services outside the practice for people who might not want to see their family doctor are also sorely lacking. A clear need exists to provide patients with more information. Finally, the authors found that group practices and those with female partners are most likely to give high priority to family planning issues in their leaflets.

Consent information leaflets – readable or unreadable?

Science.gov (United States)

Graham, Caroline; Reynard, John M; Turney, Benjamin W

2016-01-01

Objective The objective of this article is to assess the readability of leaflets about urological procedures provided by the British Association of Urological Surgeons (BAUS) to evaluate their suitability for providing information. Methods Information leaflets were assessed using three measures of readability: Flesch Reading Ease, Flesch-Kincaid and Simple Measure of Gobbledygook (SMOG) grade formulae. The scores were compared with national literacy statistics. Results Relatively good readability was demonstrated using the Flesch Reading Ease (53.4–60.1) and Flesch-Kincaid Grade Level (6.5–7.6) methods. However, the average SMOG index (14.0–15.0) for each category suggests that the majority of the leaflets are written above the reading level of an 18-year-old. Using national literacy statistics, at least 43% of the population will have significant difficultly understanding the majority of these leaflets. Conclusions The results suggest that comprehension of the leaflets provided by the BAUS is likely to be poor. These leaflets may be used as an adjunct to discussion but it is essential to ensure that all the information necessary to make an informed decision has been conveyed in a way that can be understood by the patient. PMID:27867520

Fibrosis-Related Gene Expression in Single Ventricle Heart Disease.

Science.gov (United States)

Nakano, Stephanie J; Siomos, Austine K; Garcia, Anastacia M; Nguyen, Hieu; SooHoo, Megan; Galambos, Csaba; Nunley, Karin; Stauffer, Brian L; Sucharov, Carmen C; Miyamoto, Shelley D

2017-12-01

To evaluate fibrosis and fibrosis-related gene expression in the myocardium of pediatric subjects with single ventricle with right ventricular failure. Real-time quantitative polymerase chain reaction was performed on explanted right ventricular myocardium of pediatric subjects with single ventricle disease and controls with nonfailing heart disease. Subjects were divided into 3 groups: single ventricle failing (right ventricular failure before or after stage I palliation), single ventricle nonfailing (infants listed for primary transplantation with normal right ventricular function), and stage III (Fontan or right ventricular failure after stage III). To evaluate subjects of similar age and right ventricular volume loading, single ventricle disease with failure was compared with single ventricle without failure and stage III was compared with nonfailing right ventricular disease. Histologic fibrosis was assessed in all hearts. Mann-Whitney tests were performed to identify differences in gene expression. Collagen (Col1α, Col3) expression is decreased in single ventricle congenital heart disease with failure compared with nonfailing single ventricle congenital heart disease (P = .019 and P = .035, respectively), and is equivalent in stage III compared with nonfailing right ventricular heart disease. Tissue inhibitors of metalloproteinase (TIMP-1, TIMP-3, and TIMP-4) are downregulated in stage III compared with nonfailing right ventricular heart disease (P = .0047, P = .013 and P = .013, respectively). Matrix metalloproteinases (MMP-2, MMP-9) are similar between nonfailing single ventricular heart disease and failing single ventricular heart disease, and between stage III heart disease and nonfailing right ventricular heart disease. There is no difference in the prevalence of right ventricular fibrosis by histology in subjects with single ventricular failure heart disease with right ventricular failure (18%) compared with those with normal right

Fluid mechanics of heart valves.

Science.gov (United States)

Yoganathan, Ajit P; He, Zhaoming; Casey Jones, S

2004-01-01

Valvular heart disease is a life-threatening disease that afflicts millions of people worldwide and leads to approximately 250,000 valve repairs and/or replacements each year. Malfunction of a native valve impairs its efficient fluid mechanic/hemodynamic performance. Artificial heart valves have been used since 1960 to replace diseased native valves and have saved millions of lives. Unfortunately, despite four decades of use, these devices are less than ideal and lead to many complications. Many of these complications/problems are directly related to the fluid mechanics associated with the various mechanical and bioprosthetic valve designs. This review focuses on the state-of-the-art experimental and computational fluid mechanics of native and prosthetic heart valves in current clinical use. The fluid dynamic performance characteristics of caged-ball, tilting-disc, bileaflet mechanical valves and porcine and pericardial stented and nonstented bioprostheic valves are reviewed. Other issues related to heart valve performance, such as biomaterials, solid mechanics, tissue mechanics, and durability, are not addressed in this review.

Usefulness of Tricuspid Annular Diameter to Predict Late Right Sided Heart Failure in Patients With Left Ventricular Assist Device.

Science.gov (United States)

Nakanishi, Koki; Homma, Shunichi; Han, Jiho; Takayama, Hiroo; Colombo, Paolo C; Yuzefpolskaya, Melana; Garan, Arthur R; Farr, Maryjane A; Kurlansky, Paul; Di Tullio, Marco R; Naka, Yoshifumi; Takeda, Koji

2018-07-01

Although late-onset right-sided heart failure is recognized as a clinical problem in the treatment of patients with left ventricular assist devices (LVADs), the mechanism and predictors are unknown. Tricuspid valve (TV) deformation leads to the restriction of the leaflet motion and decreased coaptation, resulting in a functional tricuspid regurgitation that may act as a surrogate marker of late right-sided heart failure. This study aimed to investigate the association of preoperative TV deformation (annulus dilatation and leaflet tethering) with late right-sided heart failure development after continuous-flow LVAD implantation. The study cohort consisted of 274 patients who underwent 2-dimensional echocardiography before LVAD implantation. TV annulus diameter and tethering distance were measured in an apical 4-chamber view. Late right-sided heart failure was defined as right-sided heart failure requiring readmission and medical and/or surgical treatment after initial LVAD implantation. During a mean follow-up of 25.1 ± 19.0 months after LVAD implantation, late right-sided heart failure occurred in 33 patients (12.0%). Multivariate Cox proportional hazard analysis demonstrated that TV annulus diameter (hazard ratio 1.221 per 1 mm, p right-sided heart failure development, whereas leaflet tethering distance was not. The best cut-off value of the TV annular diameter was 41 mm (area under the curve 0.787). Kaplan-Meier analysis showed that patients with dilated TV annulus (TV annular diameter ≥41 mm) exhibited a significantly higher late right-sided heart failure occurrence than those without TV annular enlargement (log-rank p right-sided heart failure after LVAD implantation. Copyright © 2018 Elsevier Inc. All rights reserved.

Movement influences carambola leaflet chlorophyll fluorescence and temperature under sunny conditions

International Nuclear Information System (INIS)

Marler, T.E.; Lawton, P.D.

1995-01-01

Leaflets of 'Arkin', 'B-10', 'Kary', and 'Sri Kembangan' carambola (Averrhoa carambola L.) trees were restrained in a horizontal position for 3.5 h during midday under full sun conditions to determine the influence of overriding natural leaflet movement on adaxial chlorophyll fluorescence and temperature. Induced chlorophyll fluorescence obtained after 30 minutes of dark adaptation following the period of full sun exposure was affected by leaflet movement. Restrained leaflets exhibited a variable fluorescence (Fv)/peak fluorescence (Fm) of 0.48, while that of unrestrained leaflets was 0.65. Adaxial leaflet temperature of restrained leaflets was 6C higher than that of leaflets that were allowed to move. The influence of leaflet movement on temperature or chlorophyll fluorescence was not different among the four cultivars. However, mean Fv/Fm of 'Kary' and 'Sri Kembangan' was lower than that of 'B-10'. Our results indicate that the ability of carambola to change leaflet angle leads to lower temperature and higher photochemical efficiency than occurs when leaflets are not allowed to move naturally (vertically orient) under full sun conditions

Serotonin receptor 2B signaling with interstitial cell activation and leaflet remodeling in degenerative mitral regurgitation.

Science.gov (United States)

Driesbaugh, Kathryn H; Branchetti, Emanuela; Grau, Juan B; Keeney, Samuel J; Glass, Kimberly; Oyama, Mark A; Rioux, Nancy; Ayoub, Salma; Sacks, Michael S; Quackenbush, John; Levy, Robert J; Ferrari, Giovanni

2018-02-01

Mitral valve interstitial cells (MVIC) play an important role in the pathogenesis of degenerative mitral regurgitation (MR) due to mitral valve prolapse (MVP). Numerous clinical studies have observed serotonin (5HT) dysregulation in cardiac valvulopathies; however, the impact of 5HT-mediated signaling on MVIC activation and leaflet remodeling in MVP have been investigated to a limited extent. Here we test the hypothesis that 5HT receptors (5HTRs) signaling contributes to MVP pathophysiology. Diseased human MV leaflets were obtained during cardiac surgery for MVP; normal MV leaflets were obtained from heart transplants. MV RNA was used for microarray analysis of MVP patients versus control, highlighting genes that indicate the involvement of 5HTR pathways and extracellular matrix remodeling in MVP. Human MV leaflets were also studied in vitro and ex vivo with biomechanical testing to assess remodeling in the presence of a 5HTR2B antagonist (LY272015). MVP leaflets from Cavalier King Charles Spaniels were used as a naturally acquired in vivo model of MVP. These canine MVP leaflets (N=5/group) showed 5HTR2B upregulation. This study also utilized CB57.1ML/6 mice in order to determine the effect of Angiotensin II infusion on MV remodeling. Histological analysis showed that MV thickening due to chronic Angiotensin II remodeling is mitigated by a 5HTR2B antagonist (LY272015) but not by 5HTR2A inhibitors. In humans, MVP is associated with an upregulation in 5HTR2B expression and increased 5HT receptor signaling in the leaflets. Antagonism of 5HTR2B mitigates MVIC activation in vitro and MV remodeling in vivo. These observations support the view that 5HTR signaling is involved not only in previously reported 5HT-related valvulopathies, but it is also involved in the pathological remodeling of MVP. Copyright © 2018 Elsevier Ltd. All rights reserved.

Are anticoagulant independent mechanical valves within reach-fast prototype fabrication and in vitro testing of innovative bi-leaflet valve models.

Science.gov (United States)

Scotten, Lawrence N; Siegel, Rolland

2015-08-01

Exploration for causes of prosthetic valve thrombogenicity has frequently focused on forward or post-closure flow detail. In prior laboratory studies, we uncovered high amplitude flow velocities of short duration close to valve closure implying potential for substantial shear stress with subsequent initiation of blood coagulation pathways. This may be relevant to widely accepted clinical disparity between mechanical and tissue valves vis-à-vis thrombogenicity. With a series of prototype bi-leaflet mechanical valves, we attempt reduction of closure related velocities with the objective of identifying a prototype valve with thrombogenic potential similar to our tissue valve control. This iterative design approach may find application in preclinical assessment of valves for anticoagulation independence. Tested valves included: prototype mechanical bi-leaflet BVs (n=56), controls (n=2) and patented early prototype mechanicals (n=2) from other investigators. Pulsatile and quasi-steady flow systems were used for testing. Projected dynamic valve area (PDVA) was measured using previously described novel technology. Flow velocity over the open and closing periods was determined by volumetric flow rate/PDVA. For the closed valve interval, use was made of data obtained from quasi-steady back pressure/flow tests. Performance was ranked by a proposed thrombogenicity potential index (TPI) relative to tissue and mechanical control valves. Optimization of the prototype valve designs lead to a 3-D printed model (BV3D). For the mitral/aortic site, BV3D has lower TPI (1.10/1.47) relative to the control mechanical valve (3.44/3.93) and similar to the control tissue valve (ideal TPI ≤1.0). Using unique technology, rapid prototyping and thrombogenicity ranking, optimization of experimental valves for reduced thrombogenic potential was expedited and simplified. Innovative mechanical valve configurations were identified that merit consideration for further development which may bring

Exergames versus self-regulated exercises with instruction leaflets to improve adherence during geriatric rehabilitation: a randomized controlled trial

OpenAIRE

Oesch, Peter; Kool, Jan; Fernandez-Luque, Luis; Brox, Ellen; Evertsen, Gunn; Civit, Anton; Hilfiker, Roger; Bachmann, Stefan

2017-01-01

Background Improving mobility in elderly persons is a primary goal in geriatric rehabilitation. Self-regulated exercises with instruction leaflets are used to increase training volume but adherence is often low. Exergames may improve adherence. This study therefore compared exergames with self-regulated exercise using instruction leaflets. The primary outcome was adherence. Secondary outcomes were enjoyment, motivation and balance during walking. Methods Design: single center parallel group n...

Exergames versus self-regulated exercises with instruction leaflets to improve adherence during geriatric rehabilitation: a randomized controlled trial.

OpenAIRE

Oesch, Peter; Kool, Jan; Fernandez-Luque, Luis; Brox, Ellen; Evertsen, Gunn; Civit, Anton; Hilfiker, Roger; Bachmann, Stefan

2017-01-01

BACKGROUND Improving mobility in elderly persons is a primary goal in geriatric rehabilitation. Self-regulated exercises with instruction leaflets are used to increase training volume but adherence is often low. Exergames may improve adherence. This study therefore compared exergames with self-regulated exercise using instruction leaflets. The primary outcome was adherence. Secondary outcomes were enjoyment, motivation and balance during walking. METHODS Design: single center para...

Dysfunction of an On-X Heart Valve by Pannus.

Science.gov (United States)

Abad, Cipriano; Urso, Stefano; Gomez, Elsa; De la Vega, Maria

2016-09-01

A 68-year-old woman with a history of previous double-valve replacement with On-X mechanical heart valves presented with clinical, echocardiographic and cardiac catheterization signs of obstruction of the On-X tricuspid heart valve prosthesis. The patient was successfully reoperated, but at surgery the valve was seen to be invaded by an abnormal overgrowth of pannus that blocked one of the leaflets. A small amount of non-obstructive fresh thrombus was also observed. The valve was successfully replaced with a biological heart valve prosthesis. The patient was discharged home, and is doing well four months after the operation, when echocardiography demonstrated normal function in the tricuspid valve. The present case represents the first ever report of pannus formation and subsequent dysfunction in an On-X heart valve, and also the first case of tricuspid valve malfunction and obstruction using this type of heart valve substitute.

Iodine leaflets in chapter D5 'Distribution of iodine pills'

International Nuclear Information System (INIS)

1981-01-01

Jodine leaflet A will be distributed together with iodine pills in a nuclear disaster. Iodine leaflet B is suitable for informing the public in advance. Iodine leaflet C informs physicians in a scientific way on the benefits and risk of iodine pills. (orig./HP) [de

Possible Subclinical Leaflet Thrombosis in Bioprosthetic Aortic Valves

DEFF Research Database (Denmark)

Makkar, Raj R; Fontana, Gregory; Jilaihawi, Hasan

2015-01-01

BACKGROUND: A finding of reduced aortic-valve leaflet motion was noted on computed tomography (CT) in a patient who had a stroke after transcatheter aortic-valve replacement (TAVR) during an ongoing clinical trial. This finding raised a concern about possible subclinical leaflet thrombosis...... patients and 1 of 115 patients, respectively; P=0.007). CONCLUSIONS: Reduced aortic-valve leaflet motion was shown in patients with bioprosthetic aortic valves. The condition resolved with therapeutic anticoagulation. The effect of this finding on clinical outcomes including stroke needs further...

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.

Advertising, expectations and informed consent: the contents and functions of acupuncture leaflets.

Science.gov (United States)

Bishop, Felicity L; Salmon, Cathy

2013-12-01

To evaluate the content of patient information leaflets about acupuncture. 401 patient information leaflets were obtained from practising UK acupuncturists and subjected to content and thematic analysis. 59% of included leaflets were from NHS physiotherapists. Almost all the leaflets defined acupuncture and the majority explained how it might work, described the treatment process and placed it in a historical context. Most described possible benefits and risks of acupuncture and discussed contraindications and safety. Just under a third of leaflets (120, 30%) suggested conditions that might be helped by acupuncture, most commonly musculoskeletal pain, arthritis and injuries. By emphasising differences between individuals in acupuncture treatments and responsiveness, the leaflets fostered hope for positive effects without making any guarantees. Information leaflets are broadly consistent with the evidence for acupuncture, but some claims are inconsistent with official advice from advertising regulators. An ethically sound, scientifically grounded and psychologically effective leaflet should accurately convey both benefits and risks of treatment, optimise patients' expectations and allay concerns about needling. This study suggests that acupuncture leaflets might achieve these multiple functions but care should be taken to ensure adequate coverage of risks.

Readability of Malaria Medicine Information Leaflets in Nigeria ...

African Journals Online (AJOL)

Purpose: To assess the readability of malaria medicines information leaflets available in Nigeria. Methods: Fourty five leaflets were assessed using the Simplified Measure of Gobbledygook (SMOG) readability test and by examining them for paper type, font size type, use of symbols and pictograms, and bilingual information ...

Comprehensive 4-stage categorization of bicuspid aortic valve leaflet morphology by cardiac MRI in 386 patients.

Science.gov (United States)

Murphy, I G; Collins, J; Powell, A; Markl, M; McCarthy, P; Malaisrie, S C; Carr, J C; Barker, A J

2017-08-01

Bicuspid aortic valve (BAV) disease is heterogeneous and related to valve dysfunction and aortopathy. Appropriate follow up and surveillance of patients with BAV may depend on correct phenotypic categorization. There are multiple classification schemes, however a need exists to comprehensively capture commissure fusion, leaflet asymmetry, and valve orifice orientation. Our aim was to develop a BAV classification scheme for use at MRI to ascertain the frequency of different phenotypes and the consistency of BAV classification. The BAV classification scheme builds on the Sievers surgical BAV classification, adding valve orifice orientation, partial leaflet fusion and leaflet asymmetry. A single observer successfully applied this classification to 386 of 398 Cardiac MRI studies. Repeatability of categorization was ascertained with intraobserver and interobserver kappa scores. Sensitivity and specificity of MRI findings was determined from operative reports, where available. Fusion of the right and left leaflets accounted for over half of all cases. Partial leaflet fusion was seen in 46% of patients. Good interobserver agreement was seen for orientation of the valve opening (κ = 0.90), type (κ = 0.72) and presence of partial fusion (κ = 0.83, p < 0.0001). Retrospective review of operative notes showed sensitivity and specificity for orientation (90, 93%) and for Sievers type (73, 87%). The proposed BAV classification schema was assessed by MRI for its reliability to classify valve morphology in addition to illustrating the wide heterogeneity of leaflet size, orifice orientation, and commissural fusion. The classification may be helpful in further understanding the relationship between valve morphology, flow derangement and aortopathy.

Diet and Colorectal Cancer Risk: Evaluation of a Nutrition Education Leaflet

Science.gov (United States)

Dyer, K. J.; Fearon, K. C. H.; Buckner, K.; Richardson, R. A.

2005-01-01

Objective: To evaluate the effect of a needs-based, nutrition education leaflet on nutritional knowledge. Design: Comparison of nutritional knowledge levels before and after exposure to a nutrition education leaflet. Setting: A regional colorectal out-patient clinic in Edinburgh. Method: A nutrition education leaflet, based on an earlier…

Ex vivo stretch reveals altered mechanical properties of isolated dystrophin-deficient hearts.

Directory of Open Access Journals (Sweden)

Matthew S Barnabei

Full Text Available Duchenne muscular dystrophy (DMD is a progressive and fatal disease of muscle wasting caused by loss of the cytoskeletal protein dystrophin. In the heart, DMD results in progressive cardiomyopathy and dilation of the left ventricle through mechanisms that are not fully understood. Previous reports have shown that loss of dystrophin causes sarcolemmal instability and reduced mechanical compliance of isolated cardiac myocytes. To expand upon these findings, here we have subjected the left ventricles of dystrophin-deficient mdx hearts to mechanical stretch. Unexpectedly, isolated mdx hearts showed increased left ventricular (LV compliance compared to controls during stretch as LV volume was increased above normal end diastolic volume. During LV chamber distention, sarcomere lengths increased similarly in mdx and WT hearts despite greater excursions in volume of mdx hearts. This suggests that the mechanical properties of the intact heart cannot be modeled as a simple extrapolation of findings in single cardiac myocytes. To explain these findings, a model is proposed in which disruption of the dystrophin-glycoprotein complex perturbs cell-extracellular matrix contacts and promotes the apparent slippage of myocytes past each other during LV distension. In comparison, similar increases in LV compliance were obtained in isolated hearts from β-sarcoglycan-null and laminin-α(2 mutant mice, but not in dysferlin-null mice, suggesting that increased whole-organ compliance in mdx mice is a specific effect of disrupted cell-extracellular matrix contacts and not a general consequence of cardiomyopathy via membrane defect processes. Collectively, these findings suggest a novel and cell-death independent mechanism for the progressive pathological LV dilation that occurs in DMD.

Quality assessment of patient leaflets on misoprostol-induced labour

DEFF Research Database (Denmark)

Clausen, Jette Aaroe; Juhl, Mette; Rydahl, Eva

2016-01-01

=13). Design: Patient leaflets were evaluated according to a validated scoring tool (International Patient Decision Aid Standards instrument, IPDAS), core elements in the Danish Health Act, and items regarding off-label use and non-registered medication. Two of the authors scored all leaflets...

Dysfunction of mechanical heart valve prosthesis: experience with surgical management in 48 patients

Science.gov (United States)

Ma, Wei-Guo; Hou, Bin; Abdurusul, Adiljan; Gong, Ding-Xu; Tang, Yue; Chang, Qian; Xu, Jian-Ping

2015-01-01

Background Dysfunction of mechanical heart valve prostheses is an unusual but potentially lethal complication after mechanical prosthetic valve replacement. We seek to report our experience with mechanical valve dysfunction regarding etiology, surgical techniques and early outcomes. Methods Clinical data of 48 patients with mechanical valve dysfunction surgically treated between October 1996 and June 2011 were analyzed. Results Mean age was 43.7±10.9 years and 34 were female (70.8%). The median interval from primary valve implantation to dysfunction was 44.5 months (range, 1 hour to 20 years). There were 21 emergent and 27 elective reoperations. The etiology was thrombosis in 19 cases (39.6%), pannus in 12 (25%), thrombosis and pannus in 11 (22.9%), improper disc orientation in 2 (4.1%), missing leaflet in 1 (2.1%), excessively long knot end in 1 (2.1%), endogenous factor in 1 (2.1%) and unidentified in 1 (2.1%). Surgical procedure was mechanical valve replacement in 37 cases (77.1%), bioprosthetic valve replacement in 7 (14.9%), disc rotation in 2 (4.2%) and excision of excessive knot end in 1 (2.1%). Early deaths occurred in 7 patients (14.6%), due to low cardiac output in 3 (6.3%), multi-organ failure in 2 (4.2%) and refractory ventricular fibrillation in 2 (4.2%). Complications occurred in 10 patients (20.8%). Conclusions Surgical management of mechanical valve dysfunction is associated with significant mortality and morbidity. Earlier identification and prompt reoperation are vital to achieving better clinical outcomes. The high incidence of thrombosis in this series highlights the need for adequate anticoagulation and regular follow-up after mechanical valve replacement. PMID:26793354

Developments in mechanical heart valve prosthesis

Indian Academy of Sciences (India)

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 ...

Crutches, confetti or useful tools? Professionals' views on and use of health education leaflets.

Science.gov (United States)

Murphy, S; Smith, C

1993-06-01

This paper examines the views on and use of health education leaflets by a number of professional groups: health visitors, midwives, occupational health workers, pharmacists and school health education co-ordinators. Eighty nine percent currently obtain leaflets from health promotion units, with the exception of health visitors, professionals are largely satisfied with the units' service. Seventy six percent use commercial or sponsored leaflets primarily because of the large numbers and topics that are available. The numbers and type of leaflets used were found to vary across the professions. All professionals see an increasingly important role for leaflets in their work. A number of them, pharmacists and occupational health workers in particular, saw the numbers they use rising. These views were accompanied by lower levels of belief in a leaflets ability to increase knowledge and behaviour as well as lower levels of satisfaction with current leaflet use and a concern over the public's reception of leaflets. Methods of leaflet distribution to the public largely reflect the professionals' work contexts. Most popular were handing out leaflets with advice, leaving them in a public place and using them as a back-up to a meeting. A number of contradictions emerge between distribution practices and perceived effectiveness. Few professionals thought leaving leaflets in a public place was effective, and few health visitors and midwives believed giving leaflets to the family of a client was effective despite large numbers doing so. The implications of these findings for health promotion policy and practice are discussed.

Natural history of subclinical leaflet thrombosis affecting motion in bioprosthetic aortic valves

DEFF Research Database (Denmark)

Sondergaard, Lars; De Backer, Ole; Kofoed, Klaus F

2017-01-01

. No patients developed symptoms of valve dysfunction and leaflet thickening was not clearly associated with any clinical events. Conclusions: Subclinical leaflet thrombosis is a common finding after TAVI and SAVR, and may progress from normal leaflet over HALT to the more severe HAM. The phenomenon can develop...

Fluence of Product Leaflets on Purchasing Behaviour in Times of Crisis

Directory of Open Access Journals (Sweden)

Halina Starzyczná

2015-01-01

Full Text Available This paper presents partial results of primary research on consumer purchasing behaviour with regards to the utilization of product leaflets. It deals with the consumer reaction on the use of these leaflets. The main goal is to assess the impulse to purchase goods on the basis of promotional leaflets in mailboxes, depending on the personal characteristics of the consumer. Partial goals are a brief theoretical basis of the examined issues and selected results of secondary research on consumer behaviour based on available statistical data and information. Consumer behaviour changes drastically in times of crisis. Czech consumer is addressed daily by a specific communication media of store chains – the leaflets. These appear daily in mailboxes and are generally positively accepted. There are also negative opinions, both from consumers as well as the EU. Respondents were asked about their financial situation, to what extent they change their buying behaviour with respect to the income level of households. It turned out that the impulse to purchase goods on the basis of promotional leaflets in mailboxes does not depend on the age and sex of respondents, but depends on the income level and education. The largest proportion of respondents considers leaflets because of promotional discounts.

Readability of medicinal package leaflets: a systematic review.

Science.gov (United States)

Pires, Carla; Vigário, Marina; Cavaco, Afonso

2015-01-01

OBJECTIVE To review studies on the readability of package leaflets of medicinal products for human use. METHODS We conducted a systematic literature review between 2008 and 2013 using the keywords "Readability and Package Leaflet" and "Readability and Package Insert" in the academic search engine Biblioteca do Conhecimento Online, comprising different bibliographic resources/databases. The preferred reporting items for systematic reviews and meta-analyses criteria were applied to prepare the draft of the report. Quantitative and qualitative original studies were included. Opinion or review studies not written in English, Portuguese, Italian, French, or Spanish were excluded. RESULTS We identified 202 studies, of which 180 were excluded and 22 were enrolled [two enrolling healthcare professionals, 10 enrolling other type of participants (including patients), three focused on adverse reactions, and 7 descriptive studies]. The package leaflets presented various readability problems, such as complex and difficult to understand texts, small font size, or few illustrations. The main methods to assess the readability of the package leaflet were usability tests or legibility formulae. Limitations with these methods included reduced number of participants; lack of readability formulas specifically validated for specific languages (e.g., Portuguese); and absence of an assessment on patients literacy, health knowledge, cognitive skills, levels of satisfaction, and opinions. CONCLUSIONS Overall, the package leaflets presented various readability problems. In this review, some methodological limitations were identified, including the participation of a limited number of patients and healthcare professionals, the absence of prior assessments of participant literacy, humor or sense of satisfaction, or the predominance of studies not based on role-plays about the use of medicines. These limitations should be avoided in future studies and be considered when interpreting the results.

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.

Imaging diagnosis of congenital heart disease with single coronary artery

International Nuclear Information System (INIS)

Zhu Ming; Li Yuhua; Zhong Yumin; Sun Aimin

2003-01-01

Objective: To report 56 cases of congenital heart disease with congenital single coronary artery and to evaluate the imaging diagnostic techniques. Methods: All 56 patients with congenital single coronary artery underwent angiocardiography. Contrast enhancement magnetic resonance angiography (CE MRA) was performed in 4 cases. 48 cases were confirmed by operation. Results: In these 56 cases, single left coronary artery was found in 44 cases and single right coronary artery was found in 12. Conclusion: Congenital heart disease with congenital single coronary artery is not rare and correct diagnosis is very important for surgery

Mitral valve m-mode echo in complete heart block with atrial tachycardia

Directory of Open Access Journals (Sweden)

Kalathingathodika Sajeer

2013-01-01

Full Text Available We report a 48-year-old man who presented with history of syncope. Electrocardiogram on admission showed infrahisian complete heart block with a ventricular rate of 36 beats per min with wide QRS junctional escape and atrial rate was 188 beats per min. Transthoracic echocardiogram showed fine vibratory movement of both mitral leaflet tips. M-mode evaluation of mitral leaflets showed multiple ′a′ waves corresponding to atrial tachycardia rate.

Preparation, validation and user-testing of pictogram-based patient information leaflets for hemodialysis patients.

Science.gov (United States)

Mateti, Uday Venkat; Nagappa, Anantha Naik; Attur, Ravindra Prabhu; Bairy, Manohar; Nagaraju, Shankar Prasad; Mallayasamy, Surulivelrajan; Vilakkathala, Rajesh; Guddattu, Vasudev; Balkrishnan, Rajesh

2015-11-01

Patient information leaflets are universally-accepted resources to educate the patients/users about their medications, disease and lifestyle modification. The objective of the study was to prepare, validate and perform user-testing of pictogram-based patient information leaflets (P-PILs) among hemodialysis (HD) patients. The P-PILs are prepared by referring to the primary, secondary and tertiary resources. The content and pictograms of the leaflet have been validated by an expert committee consisting of three nephrologists and two academic pharmacists. The Baker Able Leaflet Design has been applied to develop the layout and design of the P-PILs. Quasi-experimental pre- and post-test design without control group was conducted on 81 HD patients for user-testing of P-PILs. The mean Baker Able Leaflet Design assessment score for English version of the leaflet was 28, and 26 for Kannada version. The overall user-testing knowledge assessment mean scores were observed to have significantly improved from 44.25 to 69.62 with p value information leaflets can be considered an effective educational tool for HD patients.

Mechanical circulatory treatment of advanced heart failure

DEFF Research Database (Denmark)

Løgstrup, Brian B; Vase, Henrik; Gjedsted, Jakob

2016-01-01

Heart failure is one of the most common causes of morbidity and mortality worldwide. When patients cease to respond adequately to optimal medical therapy mechanical circulatory support has been promising. The advent of mechanical circulatory support devices has allowed significant improvements...... in patient survival and quality of life for those with advanced or end-stage heart failure. We provide a general overview of current mechanical circulatory support devices encompassing options for both short- and long-term ventricular support....

Characterization of mechanical properties of pericardium tissue using planar biaxial tension and flexural deformation.

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Murdock, Kyle; Martin, Caitlin; Sun, Wei

2018-01-01

Flexure is an important mode of deformation for native and bioprosthetic heart valves. However, mechanical characterization of bioprosthetic leaflet materials has been done primarily through planar tensile testing. In this study, an integrated experimental and computational cantilever beam bending test was performed to characterize the flexural properties of glutaraldehyde-treated bovine and porcine pericardium of different thicknesses. A strain-invariant based structural constitutive model was used to model the pericardial mechanical behavior quantified through the bending tests of this study and the planar biaxial tests previously performed. The model parameters were optimized through an inverse finite element (FE) procedure in order to describe both sets of experimental data. The optimized material properties were implemented in FE simulations of transcatheter aortic valve (TAV) deformation. It was observed that porcine pericardium TAV leaflets experienced significantly more flexure than bovine when subjected to opening pressurization, and that the flexure may be overestimated using a constitutive model derived from purely planar tensile experimental data. Thus, modeling of a combination of flexural and biaxial tensile testing data may be necessary to more accurately describe the mechanical properties of pericardium, and to computationally investigate bioprosthetic leaflet function and design. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

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

2015-03-01

The development of advanced scaffolds that recapitulate the anisotropic mechanical behavior and biological functions of the extracellular matrix in leaflets would be transformative for heart valve tissue engineering. In this study, anisotropic mechanical properties were established in poly(ethylene glycol) (PEG) hydrogels by crosslinking stripes of 3.4 kDa PEG diacrylate (PEGDA) within 20 kDa PEGDA base hydrogels using a photolithographic patterning method. Varying the stripe width and spacing resulted in a tensile elastic modulus parallel to the stripes that was 4.1-6.8 times greater than that in the perpendicular direction, comparable to the degree of anisotropy between the circumferential and radial orientations in native valve leaflets. Biomimetic PEG-peptide hydrogels were prepared by tethering the cell-adhesive peptide RGDS and incorporating the collagenase-degradable peptide PQ (GGGPQG↓IWGQGK) into the polymer network. The specific amounts of RGDS and PEG-PQ within the resulting hydrogels influenced the elongation, de novo extracellular matrix deposition and hydrogel degradation behavior of encapsulated valvular interstitial cells (VICs). In addition, the morphology and activation of VICs grown atop PEG hydrogels could be modulated by controlling the concentration or micro-patterning profile of PEG-RGDS. These results are promising for the fabrication of PEG-based hydrogels using anatomically and biologically inspired scaffold design features for heart valve tissue engineering. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Ventricular assist device use in single ventricle congenital heart disease.

Science.gov (United States)

Carlo, Waldemar F; Villa, Chet R; Lal, Ashwin K; Morales, David L

2017-11-01

As VAD have become an effective therapy for end-stage heart failure, their application in congenital heart disease has increased. Single ventricle congenital heart disease introduces unique physiologic challenges for VAD use. However, with regard to the mixed clinical results presented within this review, we suggest that patient selection, timing of implant, and center experience are all important contributors to outcome. This review focuses on the published experience of VAD use in single ventricle patients and details physiologic challenges and novel approaches in this growing pediatric and adult population. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Contribution of ankyrin-band 3 complexes to the organization and mechanical properties of the membrane skeleton of human erythrocyte

Energy Technology Data Exchange (ETDEWEB)

Shen, B.W. [Argonne National Lab., IL (United States). Biological and Medical Research Div.

1995-02-01

To understand the role of ankyrin-band 3 complexes in the organization of the spectrin-based membrane skeleton and its contribution to the mechanical properties of human erythrocytes, intact skeletons and single-layered skeleton leaflets were prepared from intact and physically sheared membrane ghosts, expanded in low salt buffer, and examined by transmission electron microscopy. While the structures of intact skeletons and single-layered skeleton leaflets shared many common features, including rigid junctional complexes of spectrin, actin, and band 4.1; short stretches ({approximately}50 {angstrom}) of flexible spectrin filaments; and globular masses of ankyrin-band 3 complexes situated close to the middle of the spectrin filaments, the definition of structural units in the intact skeleton is obscured by the superposition of the two layers. However, the spatial disposition of structural elements can be clearly defined in the images of the single-layered skeleton leaflets. Partially expanded skeletal leaflets contain conglomerates of ankyrin-band 3 complexes arranged in a circular or clove-leaf configuration that straddles multiple strands of thick spectrin cables, presumably reflecting the association of ankyrin-band 3 complexes on neighboring spectrin tetramers as well as the lateral association of the spectrin filaments. Hyperexpansion of the skeleton leaflets led to dissociation of the conglomerates of ankyrin-band 3 complexes, full-extension of the spectrin tetramers, and separation of the individual strands of spectrin tetramers. Clearly defined stands of spectrin tetramers in the hyperexpanded single-layered skeletal leaflets often contained two sets of globular protein masses that divided the spectrin tetramers into three segments of approximately equal length.

Getting to the Outer Leaflet: Physiology of Phosphatidylserine Exposure at the Plasma Membrane.

Science.gov (United States)

Bevers, Edouard M; Williamson, Patrick L

2016-04-01

Phosphatidylserine (PS) is a major component of membrane bilayers whose change in distribution between inner and outer leaflets is an important physiological signal. Normally, members of the type IV P-type ATPases spend metabolic energy to create an asymmetric distribution of phospholipids between the two leaflets, with PS confined to the cytoplasmic membrane leaflet. On occasion, membrane enzymes, known as scramblases, are activated to facilitate transbilayer migration of lipids, including PS. Recently, two proteins required for such randomization have been identified: TMEM16F, a scramblase regulated by elevated intracellular Ca(2+), and XKR8, a caspase-sensitive protein required for PS exposure in apoptotic cells. Once exposed at the cell surface, PS regulates biochemical reactions involved in blood coagulation, and bone mineralization, and also regulates a variety of cell-cell interactions. Exposed on the surface of apoptotic cells, PS controls their recognition and engulfment by other cells. This process is exploited by parasites to invade their host, and in specialized form is used to maintain photoreceptors in the eye and modify synaptic connections in the brain. This review discusses what is known about the mechanism of PS exposure at the surface of the plasma membrane of cells, how actors in the extracellular milieu sense surface exposed PS, and how this recognition is translated to downstream consequences of PS exposure. Copyright © 2016 the American Physiological Society.

Promoting chlamydia screening with posters and leaflets in general practice--a qualitative study.

Science.gov (United States)

Freeman, Elaine; Howell-Jones, Rebecca; Oliver, Isabel; Randall, Sarah; Ford-Young, William; Beckwith, Philippa; McNulty, Cliodna

2009-10-12

General practice staff are reluctant to discuss sexual health opportunistically in all consultations. Health promotion materials may help alleviate this barrier. Chlamydia screening promotion posters and leaflets, produced by the English National Chlamydia Screening Programme (NCSP), have been available to general practices, through local chlamydia screening offices, since its launch. In this study we explored the attitudes of general practice staff to these screening promotional materials, how they used them, and explored other promotional strategies to encourage chlamydia screening. Twenty-five general practices with a range of screening rates, were purposively selected from six NCSP areas in England. In focus groups doctors, nurses, administrative staff and receptionists were encouraged to discuss candidly their experiences about their use and opinions of posters, leaflets and advertising to promote chlamydia screening. Researchers observed whether posters and leaflets were on display in reception and/or waiting areas. Data were collected and analysed concurrently using a stepwise framework analytical approach. Although two-thirds of screening practices reported that they displayed posters and leaflets, they were not prominently displayed in most practices. Only a minority of practices reported actively using screening promotional materials on an ongoing basis. Most staff in all practices were not following up the advertising in posters and leaflets by routinely offering opportunistic screening to their target population. Some staff in many practices thought posters and leaflets would cause offence or embarrassment to their patients. Distribution of chlamydia leaflets by receptionists was thought to be inappropriate by some practices, as they thought patients would be offended when being offered a leaflet in a public area. Practice staff suggested the development of pocket-sized leaflets. The NCSP should consider developing a range of more discrete but eye

Promoting chlamydia screening with posters and leaflets in general practice - a qualitative study

Science.gov (United States)

Freeman, Elaine; Howell-Jones, Rebecca; Oliver, Isabel; Randall, Sarah; Ford-Young, William; Beckwith, Philippa; McNulty, Cliodna

2009-01-01

Background General practice staff are reluctant to discuss sexual health opportunistically in all consultations. Health promotion materials may help alleviate this barrier. Chlamydia screening promotion posters and leaflets, produced by the English National Chlamydia Screening Programme (NCSP), have been available to general practices, through local chlamydia screening offices, since its launch. In this study we explored the attitudes of general practice staff to these screening promotional materials, how they used them, and explored other promotional strategies to encourage chlamydia screening. Methods Twenty-five general practices with a range of screening rates, were purposively selected from six NCSP areas in England. In focus groups doctors, nurses, administrative staff and receptionists were encouraged to discuss candidly their experiences about their use and opinions of posters, leaflets and advertising to promote chlamydia screening. Researchers observed whether posters and leaflets were on display in reception and/or waiting areas. Data were collected and analysed concurrently using a stepwise framework analytical approach. Results Although two-thirds of screening practices reported that they displayed posters and leaflets, they were not prominently displayed in most practices. Only a minority of practices reported actively using screening promotional materials on an ongoing basis. Most staff in all practices were not following up the advertising in posters and leaflets by routinely offering opportunistic screening to their target population. Some staff in many practices thought posters and leaflets would cause offence or embarrassment to their patients. Distribution of chlamydia leaflets by receptionists was thought to be inappropriate by some practices, as they thought patients would be offended when being offered a leaflet in a public area. Practice staff suggested the development of pocket-sized leaflets. Conclusion The NCSP should consider developing

Promoting chlamydia screening with posters and leaflets in general practice - a qualitative study

Directory of Open Access Journals (Sweden)

Ford-Young William

2009-10-01

Full Text Available Abstract Background General practice staff are reluctant to discuss sexual health opportunistically in all consultations. Health promotion materials may help alleviate this barrier. Chlamydia screening promotion posters and leaflets, produced by the English National Chlamydia Screening Programme (NCSP, have been available to general practices, through local chlamydia screening offices, since its launch. In this study we explored the attitudes of general practice staff to these screening promotional materials, how they used them, and explored other promotional strategies to encourage chlamydia screening. Methods Twenty-five general practices with a range of screening rates, were purposively selected from six NCSP areas in England. In focus groups doctors, nurses, administrative staff and receptionists were encouraged to discuss candidly their experiences about their use and opinions of posters, leaflets and advertising to promote chlamydia screening. Researchers observed whether posters and leaflets were on display in reception and/or waiting areas. Data were collected and analysed concurrently using a stepwise framework analytical approach. Results Although two-thirds of screening practices reported that they displayed posters and leaflets, they were not prominently displayed in most practices. Only a minority of practices reported actively using screening promotional materials on an ongoing basis. Most staff in all practices were not following up the advertising in posters and leaflets by routinely offering opportunistic screening to their target population. Some staff in many practices thought posters and leaflets would cause offence or embarrassment to their patients. Distribution of chlamydia leaflets by receptionists was thought to be inappropriate by some practices, as they thought patients would be offended when being offered a leaflet in a public area. Practice staff suggested the development of pocket-sized leaflets. Conclusion The NCSP

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

Science.gov (United States)

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

2007-05-01

Heart valve structures derived from mesenchymal cells of the endocardial cushions (ECs) are composed of highly organized cell lineages and extracellular matrix. Sox9 is a transcription factor required for both early and late stages of cartilage formation that is also expressed in the developing valves of the heart. The requirements for Sox9 function during valvulogenesis and adult valve homeostasis in mice were examined by conditional inactivation of Sox9 using Tie2-cre and Col2a1-cre transgenes. Sox9(flox/flox);Tie2-cre mice die before E14.5 with hypoplastic ECs, reduced cell proliferation and altered extracellular matrix protein (ECM) deposition. Sox9(flox/flox);Col2a1-cre mice die at birth with thickened heart valve leaflets, reduced expression of cartilage-associated proteins and abnormal ECM patterning. Thickened valve leaflets and calcium deposits, characteristic of valve disease, are observed in heterozygous adult Sox9(flox/+);Col2a1-cre mice. Therefore, Sox9 is required early in valve development for expansion of the precursor cell population and later is required for normal expression and distribution of valvular ECM proteins. These data indicate that Sox9 is required for early and late stages of valvulogenesis and identify a potential role for Sox9 in valve disease mechanisms.

Heart Transplant and Mechanical Circulatory Support in Patients With Advanced Heart Failure.

Science.gov (United States)

Sánchez-Enrique, Cristina; Jorde, Ulrich P; González-Costello, José

2017-05-01

Patients with advanced heart failure have a poor prognosis and heart transplant is still the best treatment option. However, the scarcity of donors, long waiting times, and an increasing number of unstable patients have favored the development of mechanical circulatory support. This review summarizes the indications for heart transplant, candidate evaluation, current immunosuppression strategies, the evaluation and treatment of rejection, infectious prophylaxis, and short and long-term outcomes. Regarding mechanical circulatory support, we distinguish between short- and long-term support and the distinct strategies that can be used: bridge to decision, recovery, candidacy, transplant, and destination therapy. We then discuss indications, risk assessment, management of complications, especially with long-term support, and outcomes. Finally, we discuss future challenges and how the widespread use of long-term support for patients with advanced heart failure will only be viable if their complications and costs are reduced. Copyright © 2017 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

Determination of correlation between backflow volume and mitral valve leaflet young modulus from two dimensional echocardiogram images

Science.gov (United States)

Jong, Rudiyanto P.; Osman, Kahar; Adib, M. Azrul Hisham M.

2012-06-01

Mitral valve prolapse without proper monitoring might lead to a severe mitral valve failure which eventually leads to a sudden death. Additional information on the mitral valve leaflet condition against the backflow volume would be an added advantage to the medical practitioner for their decision on the patients' treatment. A study on two dimensional echocardiography images has been conducted and the correlations between the backflow volume of the mitral regurgitation and mitral valve leaflet Young modulus have been obtained. Echocardiogram images were analyzed on the aspect of backflow volume percentage and mitral valve leaflet dimensions on different rates of backflow volume. Young modulus values for the mitral valve leaflet were obtained by using the principle of elastic deflection and deformation on the mitral valve leaflet. The results show that the backflow volume increased with the decrease of the mitral valve leaflet Young modulus which also indicate the condition of the mitral valve leaflet approaching failure at high backflow volumes. Mitral valve leaflet Young modulus values obtained in this study agreed with the healthy mitral valve leaflet Young modulus from the literature. This is an initial overview of the trend on the prediction of the behaviour between the fluid and the structure of the blood and the mitral valve which is extendable to a larger system of prediction on the mitral valve leaflet condition based on the available echocardiogram images.

Mechanism of artificial heart

CERN Document Server

Yamane, Takashi

2016-01-01

This book first describes medical devices in relation to regenerative medicine before turning to a more specific topic: artificial heart technologies. Not only the pump mechanisms but also the bearing, motor mechanisms, and materials are described, including expert information. Design methods are described to enhance hemocompatibility: main concerns are reduction of blood cell damage and protein break, as well as prevention of blood clotting. Regulatory science from R&D to clinical trials is also discussed to verify the safety and efficacy of the devices.

Infective Endocarditis of the Aortic Valve with Anterior Mitral Valve Leaflet Aneurysm

NARCIS (Netherlands)

Tomsic, Anton; Li, Wilson W. L.; van Paridon, Marieke; Bindraban, Navin R.; de Mol, Bas A. J. M.

2016-01-01

Mitral valve leaflet aneurysm is a rare and potentially devastating complication of aortic valve endocarditis. We report the case of a 48-year-old man who had endocarditis of the native aortic valve and a concomitant aneurysm of the anterior mitral valve leaflet. Severe mitral regurgitation occurred

Mitral valve-sparing procedures and prosthetic heart valve failure: A case report

Science.gov (United States)

Khan, Nasir A; Butany, Jagdish; Leong, Shaun W; Rao, Vivek; Cusimano, Robert J; Ross, Heather J

2009-01-01

Prosthetic heart valve dysfunction due to thrombus or pannus formation can be a life-threatening complication. The present report describes a 47-year-old woman who developed valvular cardiomyopathy after chorda-sparing mitral valve replacement, and subsequently underwent heart transplantation for progressive heart failure. The explanted mitral valve prosthesis showed significant thrombus and pannus leading to reduced leaflet mobility and valvular stenosis. The present report illustrates the role of the subvalvular apparatus and pannus in prosthesis dysfunction. PMID:19279993

Supra-annular Valve-in-Valve implantation reduces blood stasis on the transcatheter aortic valve leaflets.

Science.gov (United States)

Vahidkhah, Koohyar; Azadani, Ali N

2017-06-14

Leaflet thrombosis following transcatheter aortic valve replacement (TAVR) and Valve-in-Valve (ViV) procedures has been increasingly recognized. This study aimed to investigate the effect of positioning of the transcatheter aortic valve (TAV) in ViV setting on the flow dynamics aspect of post-ViV thrombosis by quantifying the blood stasis in the intra-annular and supra-annular settings. To that end, two idealized computational models, representing ViV intra-annular and supra-annular positioning of a TAV were developed in a patient-specific geometry. Three-dimensional flow fields were then obtained via fluid-solid interaction modeling to study the difference in blood residence time (BRT) on the TAV leaflets in the two settings. At the end of diastole, a strip of high BRT (⩾1.2s) region was observed on the TAV leaflets in the ViV intra-annular positioning at the fixed boundary where the leaflets are attached to the frame. Such a high BRT region was absent on the TAV leaflets in the supra-annular positioning. The maximum value of BRT on the surface of non-, right, and left coronary leaflets of the TAV in the supra-annular positioning were 53%, 11%, and 27% smaller compared to the intra-annular positioning, respectively. It was concluded that the geometric confinement of TAV by the leaflets of the failed bioprosthetic valve in ViV intra-annular positioning increases the BRT on the leaflets and may act as a permissive factor in valvular thrombosis. The absence of such a geometric confinement in the ViV supra-annular positioning leads to smaller BRT and subsequently less likelihood of leaflet thrombosis. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of the sinus of valsalva on the closing motion of bileaflet prosthetic heart valves.

Science.gov (United States)

Ohta, Y; Kikuta, Y; Shimooka, T; Mitamura, Y; Yuhta, T; Dohi, T

2000-04-01

Conventional bileaflet prosthetic mechanical heart valves close passively with backflow. Naturally, the valve has problems associated with closure, such as backflow, water hammer effect, and fracture of the leaflet. On the other hand, in the case of the natural aortic valve, the vortex flow in the sinus of Valsalva pushes the leaflet to close, and the valve starts the closing motion earlier than the prosthetic valve as the forward flow decelerates. This closing mechanism is thought to decrease backflow at valve closure. In this study, we propose a new bileaflet mechanical valve resembling a drawbridge in shape, and the prototype valve was designed so that the leaflet closes with the help of the vortex flow in the sinus. The test valve was made of aluminum alloy, and its closing motion was compared to that of the CarboMedics (CM) valve. Both valves were driven by a computer controlled hydraulic mock circulator and were photographed at 648 frames/s by a high speed charge-coupled device (CCD) camera. Each frame of the valve motion image was analyzed with a personal computer, and the opening angles were measured. The flow rate was set as 5.0 L/min. The system was pulsed with 70 bpm, and the systolic/diastolic ratio was 0.3. Glycerin water was used as the circulation fluid at room temperature, and polystyrene particles were used to visualize the streamline. The model of the sinus of Valsalva was made of transparent silicone rubber. As a result, high speed video analysis showed that the test valve started the closing motion 41 ms earlier than the CM valve, and streamline analysis showed that the test valve had a closing mechanism similar to the natural one with the effect of vortex flow. The structure of the test valve was thought to be effective for soft closure and could solve problems associated with closure.

Automated control of the laser welding process of heart valve scaffolds

Directory of Open Access Journals (Sweden)

Weber Moritz

2016-09-01

Full Text Available Using the electrospinning process the geometry of a heart valve is not replicable by just one manufacturing process. To produce heart valve scaffolds the heart valve leaflets and the vessel have to be produced in separated spinning processes. For the final product of a heart valve they have to be mated afterwards. In this work an already existing three-axes laser was enhanced to laser weld those scaffolds. The automation control software is based on the robot operating system (ROS. The mechatronically control is done by an Arduino Mega. A graphical user interface (GUI is written with Python and Kivy.

Rapid pannus formation after few months of obstructing aortic mechanical prosthesis.

Science.gov (United States)

Al-Alao, Bassel; Simoniuk, Urszula; Heron, Brian; Parissis, Haralabos

2015-11-01

We report a rare case of a prosthetic aortic valve obstruction due to pannus formation only 3 months following aortic and mitral valve replacement. Fragments of asymmetrical pannus formation affected one of the leaflets of the bi-leaflet mechanical valve; the leaflet appeared immobile due to pannus ingrowth into the mechanical skeleton resulting in encroachment of the leaflet, which in turn became immobile. The patient successfully underwent emergency redo-aortic valve replacement.

A Nodal-independent and tissue-intrinsic mechanism controls heart-looping chirality

Science.gov (United States)

Noël, Emily S.; Verhoeven, Manon; Lagendijk, Anne Karine; Tessadori, Federico; Smith, Kelly; Choorapoikayil, Suma; den Hertog, Jeroen; Bakkers, Jeroen

2013-11-01

Breaking left-right symmetry in bilateria is a major event during embryo development that is required for asymmetric organ position, directional organ looping and lateralized organ function in the adult. Asymmetric expression of Nodal-related genes is hypothesized to be the driving force behind regulation of organ laterality. Here we identify a Nodal-independent mechanism that drives asymmetric heart looping in zebrafish embryos. In a unique mutant defective for the Nodal-related southpaw gene, preferential dextral looping in the heart is maintained, whereas gut and brain asymmetries are randomized. As genetic and pharmacological inhibition of Nodal signalling does not abolish heart asymmetry, a yet undiscovered mechanism controls heart chirality. This mechanism is tissue intrinsic, as explanted hearts maintain ex vivo retain chiral looping behaviour and require actin polymerization and myosin II activity. We find that Nodal signalling regulates actin gene expression, supporting a model in which Nodal signalling amplifies this tissue-intrinsic mechanism of heart looping.

Transmembrane protein diffusion in gel-supported dual-leaflet membranes.

Science.gov (United States)

Wang, Chih-Ying; Hill, Reghan J

2014-11-18

Tools to measure transmembrane-protein diffusion in lipid bilayer membranes have advanced in recent decades, providing a need for predictive theoretical models that account for interleaflet leaflet friction on tracer mobility. Here we address the fully three-dimensional flows driven by a (nonprotruding) transmembrane protein embedded in a dual-leaflet membrane that is supported above and below by soft porous supports (e.g., hydrogel or extracellular matrix), each of which has a prescribed permeability and solvent viscosity. For asymmetric configurations, i.e., supports with contrasting permeability, as realized for cells in contact with hydrogel scaffolds or culture media, the diffusion coefficient can reflect interleaflet friction. Reasonable approximations, for sufficiently large tracers on low-permeability supports, are furnished by a recent phenomenological theory from the literature. Interpreting literature data, albeit for hard-supported membranes, provides a theoretical basis for the phenomenological Stokes drag law as well as strengthening assertions that nonhydrodynamic interactions are important in supported bilayer systems, possibly leading to overestimates of the membrane/leaflet viscosity. Our theory provides a theoretical foundation for future experimental studies of tracer diffusion in gel-supported membranes.

Management of single-ventricle patients with Berlin Heart EXCOR Ventricular Assist Device: single-center experience.

Science.gov (United States)

Mackling, Tracey; Shah, Tejas; Dimas, Vivian; Guleserian, Kristine; Sharma, Mahesh; Forbess, Joseph; Ardura, Monica; Gross-Toalson, Jami; Lee, Ying; Journeycake, Janna; Barnes, Aliessa

2012-06-01

There are minimal data regarding chronic management of single-ventricle ventricular assist device (VAD) patients. This study aims to describe our center's multidisciplinary team management of single-ventricle patients supported long term with the Berlin Heart EXCOR Pediatric VAD. Patient #1 was a 4-year-old with double-outlet right ventricle with aortic atresia, L-looped ventricles, and heart block who developed heart failure 1 year after Fontan. She initially required extracorporeal membrane oxygenation support and was transitioned to Berlin Heart systemic VAD. She was supported for 363 days (cardiac intensive care unit [CICU] 335 days, floor 28 days). The postoperative course was complicated by intermittent infection including methicillin-resistant Staphylococcus aureus, intermittent hepatic and renal insufficiencies, and transient antithrombin, protein C, and protein S deficiencies resulting in multiple thrombi. She had a total of five pump changes over 10 months. Long-term medical management included anticoagulation with enoxaparin, platelet inhibition with aspirin and dipyridamole, and antibiotic prophylaxis using trimethoprim/sulfamethoxazole. She developed sepsis of unknown etiology and subsequently died from multiorgan failure. Patient #2 was a 4-year-old with hypoplastic left heart syndrome who developed heart failure 2 years after bidirectional Glenn shunt. At systemic VAD implantation, he was intubated with renal insufficiency. Post-VAD implantation, his renal insufficiency resolved, and he was successfully extubated to daytime nasal cannula and biphasic positive airway pressure at night. He was supported for 270 days (CICU 143 days, floor 127 days). The pump was upsized to a 50-mL pump in May 2011 for increased central venous pressures (29 mm Hg). Long-term medical management included anticoagulation with warfarin and single-agent platelet inhibition using dipyridamole due to aspirin resistance. He developed increased work of breathing requiring

Mechanical stimulation in the engineering of heart muscle.

Science.gov (United States)

Liaw, Norman Yu; Zimmermann, Wolfram-Hubertus

2016-01-15

Recreating the beating heart in the laboratory continues to be a formidable bioengineering challenge. The fundamental feature of the heart is its pumping action, requiring considerable mechanical forces to compress a blood filled chamber with a defined in- and outlet. Ventricular output crucially depends on venous loading of the ventricles (preload) and on the force generated by the preloaded ventricles to overcome arterial blood pressure (afterload). The rate of contraction is controlled by the spontaneously active sinus node and transmission of its electrical impulses into the ventricles. The underlying principles for these physiological processes are described by the Frank-Starling mechanism and Bowditch phenomenon. It is essential to consider these principles in the design and evaluation of tissue engineered myocardium. This review focuses on current strategies to evoke mechanical loading in hydrogel-based heart muscle engineering. Copyright © 2015. Published by Elsevier B.V.

Package leaflets of the most consumed medicines in Portugal: safety and regulatory compliance issues. A descriptive study

Directory of Open Access Journals (Sweden)

Carla Pires

Full Text Available CONTEXT AND OBJECTIVES: Package leaflets are necessary for safe use of medicines. The aims of the present study were: 1 to assess the compliance between the content of the package leaflets and the specifications of the pharmaceutical regulations; and 2 to identify potential safety issues for patients. DESIGN AND SETTING: Qualitative descriptive study, involving all the package leaflets of branded medicines from the three most consumed therapeutic groups in Portugal, analyzed in the Department of Pharmacoepidemiology, School of Pharmacy, University of Lisbon. METHODS: A checklist validated through an expert consensus process was used to gather the data. The content of each package leaflet in the sample was classified as compliant or non-compliant with compulsory regulatory issues (i.e. stated dosage and descriptions of adverse reactions and optional regulatory issues (i.e. adverse reaction frequency, symptoms and procedures in cases of overdose. RESULTS: A total of 651 package leaflets were identified. Overall, the package leaflets were found to be compliant with the compulsory regulatory issues. However, the optional regulatory issues were only addressed in around half of the sample of package leaflets, which made it possible to identify some situations of potentially compromised drug safety. CONCLUSION: Ideally, the methodologies for package leaflet approval should be reviewed and optimized as a way of ensuring the inclusion of the minimum essential information for safe use of medicines.

Outlet strut fracture and leaflet escape of Bjork-Shiley convexo-concave valve.

Science.gov (United States)

Uchino, Gaku; Yoshida, Hideo; Sakoda, Naoya; Hattori, Shigeru; Kawabata, Takuya; Saiki, Munehiro; Fujita, Yasufumi; Yunoki, Keiji; Hisamochi, Kunikazu; Mine, Yoshinari

2017-06-01

Prosthetic valve fracture is a serious complication and may arise in patient post-valve replacement. We experienced an outlet strut fracture and leaflet escape of a Bjork-Shiley convexo-concave valve. We performed an emergency redo mitral valve replacement and successfully retrieved the fractured strut and escaped leaflet from superficial femoral artery and the abdominal aorta. The patient showed an uneventful postoperative recovery.

The usefulness and scientific accuracy of private sector Arabic language patient drug information leaflets.

Science.gov (United States)

Sukkari, Sana R; Al Humaidan, Abdullah S; Sasich, Larry D

2012-07-01

Inadequate access to useful scientifically accurate patient information is a major cause of the inappropriate use of drugs resulting in serious personal injury and related costs to the health care system. The definition of useful scientifically accurate patient information for prescription drugs was accepted by the US Secretary of the Department of Health and Human Services in 1996 as that derived from or consistent with the US FDA approved professional product label for a drug. Previous quality content studies found that English language patient drug information leaflets distributed by US pharmacies failed to meet minimum criteria defining useful and scientifically accurate information. Evaluation forms containing the explicit elements that define useful scientifically accurate information for three drugs with known serious adverse drug reactions were created based on the current US FDA approved professional product labels. The Arabic language patient drug information leaflets for celecoxib, paroxetine, and lamotrigine were obtained locally and evaluated using a methodology similar to that used in previous quality content patient drug information studies in the US. The Arabic leaflets failed to meet the definition of useful scientifically accurate information. The celecoxib leaflet contained 30% of the required information and the paroxetine and lamotrigine leaflets contained 24% and 20%, respectively. There are several limitations to this study. The Arabic leaflets from only one commercial North American vendor were evaluated and the evaluation included a limited number of drugs. A larger study is necessary to be able to generalize these results. The study results are consistent with those of previous quality content studies of commercially available English patient drug information leaflets. The results have important implications for patients as access to a reliable source of drug information may prevent harm or limit the suffering from serious adverse drug

Danglers in Patient Information Leaflets and Technical Manuals

DEFF Research Database (Denmark)

Køhler Simonsen, Henrik

2014-01-01

in fact been proved. The analysis and the discussion showed that dangling participles are not very frequent in PILs, but much more common in technical manuals. The data showed that there were no “ludicrous” danglers,(see Matthews and Matthews 2008:146), in PILcorp. However, the analysis showed that both......Dangling participles and other types of ambiguous or unclear sentence constructions in directive and informative medical and technical texts, such as patient information leaflets (PILs) and technical manuals, render instructions unclear and potentially dangerous for the layman reader, i......, and readability on the basis of two corpora: a corpus of PILs (PILcorp) and a corpus of technical manuals (TECHcorp). The hypothesis is that patient information leaflets will contain fewer dangling constructions than technical manuals because of the strict regulations on product information texts including PILs...

The enigmatic fast leaflet rotation in Desmodium motorium

Science.gov (United States)

Lev-Yadun, Simcha

2013-01-01

I propose that the enigmatic leaflet movements in elliptical circles every few minutes of the Indian telegraph (semaphore) plant Desmodium motorium ( = D. gyrans = Hedysarum gyrans = Codariocalyx motorius), which has intrigued scientists for centuries, is a new type of butterfly or general winged arthropod mimicry by this plant. Such leaflet movement may deceive a passing butterfly searching for an un-occupied site suitable to deposit its eggs, that the plant is already occupied. It may also attract insectivorous birds, reptiles or arthropods to the plant because it looks as if it is harboring a potential prey and while they patrol there, they can find insects or other invertebrates that indeed attack the plant. The possibility that diurnal mammalian herbivores may also be deterred by these movements should not be dismissed. PMID:23603964

Posterior leaflet preservation during mitral valve replacement for rheumatic mitral stenosis.

Science.gov (United States)

Djukić, P L; Obrenović-Kirćanski, B B; Vranes, M R; Kocica, M J; Mikić, A Dj; Velinović, M M; Kacar, S M; Kovacević, N S; Parapid, B J

2006-01-01

Mitral valve replacement with posterior leaflet preservation was shown beneficial for postoperative left vetricular (LV) performance in patients with mitral regurgitation. Some authors find it beneficial even for the long term LV function. We investigated a long term effect of this technique in patients with rheumatic mitral stenosis. We studied 20 patents with mitral valve replacement due to rheumatic mitral stenosis, in the period from January 1988 to December 1989. In group A (10 patients) both leaflets and coresponding chordal excision was performed, while in group B (10 patients) the posterior leaflet was preserved. In all patients a Carbomedics valve was inserted. We compared clinical pre and postoperative status, as well as hemodynamic characteristics of the valve and left ventricle in both groups. Control echocardiographyc analysis included: maximal (PG) and mean (MG) gradients; effective valve area (AREA); telediastolic (TDV) and telesystolic (TSV) LV volume; stroke volume (SV); ejection fraction (EF); fractional shortening (FS) and segmental LV motion. The mean size of inserted valve was 26.6 in group A and 27.2 in group B. Hemodynamic data: PG (10.12 vs 11.1); MG (3.57 vs 3.87); AREA (2.35 vs 2.30); TDV 126.0 vs 114.5); TSV (42.2 vs 36.62); SV (83.7 vs 77.75); EF (63.66 vs 67.12); FS (32.66 vs 38.25). Diaphragmal segmental hypokinesis was evident in one patient from group A and in two patients from group B. In patients with rheumatic stenosis, posterior leaflet preservation did not have increased beneficial effect on left ventricular performance during long-term follow-up. An adequate posterior leaflet preservation does not change hemodynamic valvular characteristics even after long-term follow-up.

Readability Statistics of Patient Information Leaflets in a Speech and Language Therapy Department

Science.gov (United States)

Pothier, Louise; Day, Rachael; Harris, Catherine; Pothier, David D.

2008-01-01

Background: Information leaflets are commonly used in Speech and Language Therapy Departments. Despite widespread use, they can be of variable quality. Aims: To revise current departmental leaflets using the National Health Service (NHS) Toolkit for Producing Patient Information and to test the effect that this has on the readability scores of the…

Mechanical analysis of congestive heart failure caused by bundle branch block based on an electromechanical canine heart model

Energy Technology Data Exchange (ETDEWEB)

Dou Jianhong; Xia Ling; Zhang Yu; Shou Guofa [Department of Biomedical Engineering, Zhejiang University, Hangzhou 310027 (China); Wei Qing; Liu Feng; Crozier, Stuart [School of Information Technology and Electrical Engineering, University of Queensland, St Lucia, Brisbane, Queensland 4072 (Australia)], E-mail: xialing@zju.edu.cn

2009-01-21

Asynchronous electrical activation, induced by bundle branch block (BBB), can cause reduced ventricular function. However, the effects of BBB on the mechanical function of heart are difficult to assess experimentally. Many heart models have been developed to investigate cardiac properties during BBB but have mainly focused on the electrophysiological properties. To date, the mechanical function of BBB has not been well investigated. Based on a three-dimensional electromechanical canine heart model, the mechanical properties of complete left and right bundle branch block (LBBB and RBBB) were simulated. The anatomical model as well as the fiber orientations of a dog heart was reconstructed from magnetic resonance imaging (MRI) and diffusion tensor MRI (DT-MRI). Using the solutions of reaction-diffusion equations and with a strategy of parallel computation, the asynchronous excitation propagation and intraventricular conduction in BBB was simulated. The mechanics of myocardial tissues were computed with time-, sarcomere length-dependent uniaxial active stress initiated at the time of depolarization. The quantification of mechanical intra- and interventricular asynchrony of BBB was then investigated using the finite-element method with an eight-node isoparametric element. The simulation results show that (1) there exists inter- and intraventricular systolic dyssynchrony during BBB; (2) RBBB may have more mechanical synchrony and better systolic function of the left ventricle (LV) than LBBB; (3) the ventricles always move toward the early-activated ventricle; and (4) the septum experiences higher stress than left and right ventricular free walls in BBB. The simulation results validate clinical and experimental recordings of heart deformation and provide regional quantitative estimates of ventricular wall strain and stress. The present work suggests that an electromechanical heart model, incorporating real geometry and fiber orientations, may be helpful for better

Practitioner and lay perspectives of the service provision of nutrition information leaflets in primary care.

Science.gov (United States)

McClinchy, Jane; Dickinson, Angela; Barron, Duncan; Thomas, Hilary

2011-12-01

In primary care, leaflets are often used to communicate health information. Increasingly, primary healthcare practitioners need to provide dietary advice. There is limited research exploring how nutrition information leaflets are used in primary care. The present study explored practitioner and lay experiences with respect to providing and receiving nutrition information in primary care, focusing in particular on the use of leaflets for nutrition information. A qualitative design was used incorporating focus groups with 57 practitioners based at seven general practitioner practices and a purposive sample of 30 lay participants attending six Consumer Health Organisations within one primary care trust. Focus groups were taped and transcribed verbatim and data were analysed thematically, assisted by computer software n6® (QSR International Pty Ltd, Melbourne, Australia). Practitioners discussed barriers to giving nutritional advice, access to leaflets, lay receptiveness to advice and their perceptions about the value of leaflets to lay people. Food was not considered in terms of its nutritional components by lay participants and the need for nutritional information was not perceived to be relevant until they had received a medical diagnosis. Lay participants discussed the importance of receiving nutritional advice relating to their medical diagnosis and the altered status of written information that was delivered personally. Practitioner and lay groups suggested improvements to ensure that nutritional advice be supported by relevant and appropriate written information. This research has underlined the continuing importance of nutrition information leaflets and concludes that there is particular value in involving lay participants in the development of nutrition information leaflets. © 2011 The Authors. Journal of Human Nutrition and Dietetics © 2011 The British Dietetic Association Ltd.

A Coarse Grained Model for a Lipid Membrane with Physiological Composition and Leaflet Asymmetry.

Directory of Open Access Journals (Sweden)

Satyan Sharma

Full Text Available The resemblance of lipid membrane models to physiological membranes determines how well molecular dynamics (MD simulations imitate the dynamic behavior of cell membranes and membrane proteins. Physiological lipid membranes are composed of multiple types of phospholipids, and the leaflet compositions are generally asymmetric. Here we describe an approach for self-assembly of a Coarse-Grained (CG membrane model with physiological composition and leaflet asymmetry using the MARTINI force field. An initial set-up of two boxes with different types of lipids according to the leaflet asymmetry of mammalian cell membranes stacked with 0.5 nm overlap, reliably resulted in the self-assembly of bilayer membranes with leaflet asymmetry resembling that of physiological mammalian cell membranes. Self-assembly in the presence of a fragment of the plasma membrane protein syntaxin 1A led to spontaneous specific positioning of phosphatidylionositol(4,5bisphosphate at a positively charged stretch of syntaxin consistent with experimental data. An analogous approach choosing an initial set-up with two concentric shells filled with different lipid types results in successful assembly of a spherical vesicle with asymmetric leaflet composition. Self-assembly of the vesicle in the presence of the synaptic vesicle protein synaptobrevin 2 revealed the correct position of the synaptobrevin transmembrane domain. This is the first CG MD method to form a membrane with physiological lipid composition as well as leaflet asymmetry by self-assembly and will enable unbiased studies of the incorporation and dynamics of membrane proteins in more realistic CG membrane models.

Readability of Malaria Medicine Information Leaflets in Nigeria

African Journals Online (AJOL)

Erah

2010-12-18

Dec 18, 2010 ... for malaria medicines information leaflets available in Nigeria was 13.69 ± 1.70. This value is equivalent ... Health promotion and behaviour change communication ... their rational use at the community level. Readability is the ...

Creation New Patient Information Leaflets with Diabetes by Pharmacists and Assesment Conducted by Patients.

Science.gov (United States)

Arai, Motoharu; Maeda, Kazuto; Satoh, Hiroki; Miki, Akiko; Sawada, Yasufumi

2016-10-01

We created a draft of new patient information leaflets to ensure patients' proper use of drugs and to highlight safety issues and improvement plans extracted and proposed by small group discussions (SGD) with pharmacists. A total of 3 SGDs (participants: 15 pharmacists) were conducted with the aim of improving patient information leaflets for oral diabetes drugs. First, the disadvantages and advantages of the current instructions as well as requests for ideal patient information leaflets were obtained from participants. Conventional patient information leaflets that could be improved were useful to understand drug efficacy, adverse effects, and instructions for daily consumption of medicines, and to encourage patients to re-check drugs at home and inform their family of the measures to be taken in the case of adverse effects from the standpoint of patients. However, some disadvantages arose; for example, the instructions were difficult to read because of small lettering and illustrations and too much text. It was not tailored for individual patients, and descriptions about serious adverse effects caused patients much anxiety. Therefore, we have created a draft of new patient information leaflets with diabetes that are simpler and easier to understand and use concise wording and illustrations that are impactful.

Statistical characteristics of mechanical heart valve cavitation in accelerated testing.

Science.gov (United States)

Wu, Changfu; Hwang, Ned H C; Lin, Yu-Kweng M

2004-07-01

Cavitation damage has been observed on mechanical heart valves (MHVs) undergoing accelerated testing. Cavitation itself can be modeled as a stochastic process, as it varies from beat to beat of the testing machine. This in-vitro study was undertaken to investigate the statistical characteristics of MHV cavitation. A 25-mm St. Jude Medical bileaflet MHV (SJM 25) was tested in an accelerated tester at various pulse rates, ranging from 300 to 1,000 bpm, with stepwise increments of 100 bpm. A miniature pressure transducer was placed near a leaflet tip on the inflow side of the valve, to monitor regional transient pressure fluctuations at instants of valve closure. The pressure trace associated with each beat was passed through a 70 kHz high-pass digital filter to extract the high-frequency oscillation (HFO) components resulting from the collapse of cavitation bubbles. Three intensity-related measures were calculated for each HFO burst: its time span; its local root-mean-square (LRMS) value; and the area enveloped by the absolute value of the HFO pressure trace and the time axis, referred to as cavitation impulse. These were treated as stochastic processes, of which the first-order probability density functions (PDFs) were estimated for each test rate. Both the LRMS value and cavitation impulse were log-normal distributed, and the time span was normal distributed. These distribution laws were consistent at different test rates. The present investigation was directed at understanding MHV cavitation as a stochastic process. The results provide a basis for establishing further the statistical relationship between cavitation intensity and time-evolving cavitation damage on MHV surfaces. These data are required to assess and compare the performance of MHVs of different designs.

Myocardial Response to Milrinone in Single Right Ventricle Heart Disease.

Science.gov (United States)

Nakano, Stephanie J; Nelson, Penny; Sucharov, Carmen C; Miyamoto, Shelley D

2016-07-01

Empiric treatment with milrinone, a phosphodiesterase (PDE) 3 inhibitor, has become increasingly common in patients with single ventricle heart disease of right ventricular (RV) morphology (SRV); our objective was to characterize the myocardial response to PDE3 inhibition (PDE3i) in the pediatric population with SRV. Cyclic adenosine monophosphate levels, PDE activity, and phosphorylated phospholamban (PLN) were determined in explanted human ventricular myocardium from nonfailing pediatric donors (n = 10) and pediatric patients transplanted secondary to SRV. Subjects with SRV were further classified by PDE3i treatment (n = 13 with PDE3i and n = 12 without PDE3i). In comparison with nonfailing RV myocardium (n = 8), cyclic adenosine monophosphate levels are lower in patients with SRV treated with PDE3i (n = 12, P = .021). Chronic PDE3i does not alter total PDE or PDE3 activity in SRV myocardium. Compared with nonfailing RV myocardium, SRV myocardium (both with and without PDE3i) demonstrates equivalent phosphorylated PLN at the protein kinase A phosphorylation site. As evidenced by preserved phosphorylated PLN, the molecular adaptation associated with SRV differs significantly from that demonstrated in pediatric heart failure because of dilated cardiomyopathy. These alterations support a pathophysiologically distinct mechanism of heart failure in pediatric patients with SRV, which has direct implications regarding the presumed response to PDE3i treatment in this population. Copyright © 2016 Elsevier Inc. All rights reserved.

Comparative study between CardiaMed valves (freely floating valve leaflets versus St. Jude Medical (fixed valve leaflets in mitral valve replacement surgery

Directory of Open Access Journals (Sweden)

Mostafa Ahmed

2017-09-01

Conclusions: CardiaMed freely floating leaflet prostheses showed good hemodynamic characteristics. The prosthesis adequately corrects hemodynamics and is safe and no worse than the St. Jude Medical valve in the mitral valve position.

Constructing osteoarthritis through discourse – a qualitative analysis of six patient information leaflets on osteoarthritis

Directory of Open Access Journals (Sweden)

Ong Bie

2007-04-01

Full Text Available Abstract Background Health service policy in the United Kingdom emphasises the importance of self-care by patients with chronic conditions. Written information for patients about their condition is seen as an important aid to help patients look after themselves. From a discourse analysis perspective written texts such as patient information leaflets do not simply describe the reality of a medical condition and its management but by drawing on some sorts of knowledge and evidence rather than others help construct the reality of that condition. This study explored patient information leaflets on osteoarthritis (OA to see how OA was constructed and to consider the implications for self-care. Methods Systematic and repeated readings of six patient information leaflets on osteoarthritis to look for similarities and differences across leaflets, contradictions within leaflets and the resources called on to make claims about the nature of OA and its management. Results Biomedical discourse of OA as a joint disease dominated. Only one leaflet included an illness discourse albeit limited, and was also the only one to feature patient experiences of living with OA. The leaflets had different views on the causes of OA including the role of lifestyle and ageing. Most emphasised patient responsibility for preventing the progression of OA. Advice about changing behaviour such as diet and exercise was not grounded in lived experience. There were inconsistent messages about using painkillers, exercise and the need to involve professionals when making changes to lifestyle. Conclusion The nature of the discourse impacted on how OA and the respective roles of patients and professionals were depicted. Limited discourse on illness meant that the complexity of living with OA and its consequences was underestimated. Written information needs to shift from joint biology to helping patients live with osteoarthritis. Written information should incorporate patient

Low literacy and written drug information: information-seeking, leaflet evaluation and preferences, and roles for images.

Science.gov (United States)

van Beusekom, Mara M; Grootens-Wiegers, Petronella; Bos, Mark J W; Guchelaar, Henk-Jan; van den Broek, Jos M

2016-12-01

Background Low-literate patients are at risk to misinterpret written drug information. For the (co-) design of targeted patient information, it is key to involve this group in determining their communication barriers and information needs. Objective To gain insight into how people with low literacy use and evaluate written drug information, and to identify ways in which they feel the patient leaflet can be improved, and in particular how images could be used. Setting Food banks and an education institution for Dutch language training in the Netherlands. Method Semi-structured focus groups and individual interviews were held with low-literate participants (n = 45). The thematic framework approach was used for analysis to identify themes in the data. Main outcome measure Low-literate people's experience with patient information leaflets, ideas for improvements, and perceptions on possible uses for visuals. Results Patient information leaflets were considered discouraging to use, and information difficult to find and understand. Many rely on alternative information sources. The leaflet should be shorter, and improved in terms of organisation, legibility and readability. Participants thought images could increase the leaflet's appeal, help ask questions, provide an overview, help understand textual information, aid recall, reassure, and even lead to increased confidence, empowerment and feeling of safety. Conclusion Already at the stages of paying attention to the leaflet and maintaining interest in the message, low-literate patients experience barriers in the communication process through written drug information. Short, structured, visual/textual explanations can lower the motivational threshold to use the leaflet, improve understanding, and empower the low-literate target group.

Developments in mechanical heart valve prosthesis

Indian Academy of Sciences (India)

M. Senthilkumar (Newgen Imaging) 1461 1996 Oct 15 13:05:22

BHUVANESHWAR. Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences. & Technology ... affect the performance of mechanical heart valves. The clinical performance of ... those who cannot be put under anticoagulant therapy, like women who may still wish to bear children, or hemolytic patients.

Cardiovascular mechanisms of SSRI drugs and their benefits and risks in ischemic heart disease and heart failure.

Science.gov (United States)

Andrade, Chittaranjan; Kumar, Chethan B; Surya, Sandarsh

2013-05-01

Depression and heart disease are commonly comorbid. Selective serotonin reuptake inhibitors (SSRIs) are commonly used to treat depression. In March 2011, we carried out a 15-year search of PubMed for preclinical and clinical publications related to SSRIs and ischemic heart disease (IHD) or congestive heart failure (CHF). We identify and discuss a number of mechanisms by which SSRIs may influence cardiovascular functioning and health outcomes in patients with heart disease; many of the mechanisms that we present have received little attention in previous reviews. We examine studies with positive, neutral, and negative outcomes in IHD and CHF patients treated with SSRIs. SSRIs influence cardiovascular functioning and health through several different mechanisms; for example, they inhibit serotonin-mediated and collagen-mediated platelet aggregation, reduce inflammatory mediator levels, and improve endothelial function. SSRIs improve indices of ventricular functioning in IHD and heart failure without adversely affecting electrocardiographic parameters. SSRIs may also be involved in favorable or unfavorable drug interactions with medications that influence cardiovascular functions. The clinical evidence suggests that, in general, SSRIs are safe in patients with IHD and may, in fact, exert a cardioprotective effect. The clinical data are less clear in patients with heart failure, and the evidence for benefits with SSRIs is weak.

Overcoming the knowledge-behavior gap: The effect of evidence-based HPV vaccination leaflets on understanding, intention, and actual vaccination decision.

Science.gov (United States)

Wegwarth, O; Kurzenhäuser-Carstens, S; Gigerenzer, G

2014-03-10

Informed decision making requires transparent and evidence-based (=balanced) information on the potential benefit and harms of medical preventions. An analysis of German HPV vaccination leaflets revealed, however, that none met the standards of balanced risk communication. We surveyed a sample of 225 girl-parent pairs in a before-after design on the effects of balanced and unbalanced risk communication on participants' knowledge about cervical cancer and the HPV vaccination, their perceived risk, their intention to have the vaccine, and their actual vaccination decision. The balanced leaflet increased the number of participants who were correctly informed about cervical cancer and the HPV vaccine by 33 to 66 absolute percentage points. In contrast, the unbalanced leaflet decreased the number of participants who were correctly informed about these facts by 0 to 18 absolute percentage points. Whereas the actual uptake of the HPV vaccination 14 months after the initial study did not differ between the two groups (22% balanced leaflet vs. 23% unbalanced leaflet; p=.93, r=.01), the originally stated intention to have the vaccine reliably predicted the actual vaccination decision for the balanced leaflet group only (concordance between intention and actual uptake: 97% in the balanced leaflet group, rs=.92, p=.00; 60% in the unbalanced leaflet group, rs=.37, p=.08). In contrast to a unbalanced leaflet, a balanced leaflet increased people's knowledge of the HPV vaccination, improved perceived risk judgments, and led to an actual vaccination uptake, which first was robustly predicted by people's intention and second did not differ from the uptake in the unbalanced leaflet group. These findings suggest that balanced reporting about HPV vaccination increases informed decisions about whether to be vaccinated and does not undermine actual uptake. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

A global perspective on mechanical prosthetic heart valve thrombosis: Diagnostic and therapeutic challenges

Science.gov (United States)

Gürsoy, Mustafa Ozan; Kalçık, Macit; Yesin, Mahmut; Karakoyun, Süleyman; Bayam, Emrah; Gündüz, Sabahattin; Özkan, Mehmet

2016-01-01

Prosthetic valve thrombosis is one of the major causes of primary valve failure, which can be life-threatening. Multimodality imaging is necessary for determination of leaflet immobilization, cause of underlying pathology (thrombus versus pannus or both), and whether thrombolytic therapy attempt in the patient would be successful or surgery is needed. Current guidelines for the management of prosthetic valve thrombosis lack definitive class I recommendations due to lack of randomized controlled trials, and usually leave the choice of treatment to the clinician’s experience. In this review, we aimed to summarize the pathogenesis, diagnosis, and management of mechanical prosthetic valve thrombosis. PMID:28005024

PENGGUNAAN LEAFLET DALAM PENDIDIKAN GIZI DAN PENGARUHNYA TERHADAP TINGKAT PENGETAHUAN IBU

Directory of Open Access Journals (Sweden)

Susilowati Herman

2012-11-01

Full Text Available Selama ini pendidikan gizi umumnya belum memanfaatkan alat bantu pendidikan gizi secara optimal. Selain itu pesan-pesan pendidikan gizi terkadang belum dirancang dengan seksama, sesuai dengan kebutuhan sasaran. Tidak jarang dijumpai pesan yang terlalu banyak, umum atau tidak terarah. Penyampaian pesan-pesan pendidikan gizi yang dilakukan secara berulang dan disertai penggunaan alat bantu pendidikan yang dirancang dengan baik, dapat mempermudah sasaran pendidikan menangkap dan mengerti isi pesan pendidikan. Penelitian ini bertujuan menilai perubahan tingkat pengetahuan gizi sebagai hasil dari paket pendidikan gizi yang terarah dengan menggunakan alat bantu pendidikan berupa leaflet yana dibawa pulang oleh sasaran pendidikan. Sasaran pendidikan adalah ibu-ibu dari anak Balita penderita gizi buruk (KKP berat pengunjung Klinik Gizi, Puslitbang Gizi, Bogor. Kelompok pembanding adalah juga ibu-ibu dari anak Balita penderita gizi buruk pengunjung Klinik Gizi yang sama dan kepadanya juga diberikan pendidikan gizi dengan isi pesan sama, tetapi tidak diberi alat bantu pendidikan berupa leaflet. Hasil penelitian menunjukkan babwa perubahan tingkat pengetahuan gizi ibu-ibu yang diberi leaflet, lebih baik daripada pengetahuan gizi ibu-ibu kelompok pembanding.

Combined heart-kidney transplantation after total artificial heart insertion.

Science.gov (United States)

Ruzza, A; Czer, L S C; Ihnken, K A; Sasevich, M; Trento, A; Ramzy, D; Esmailian, F; Moriguchi, J; Kobashigawa, J; Arabia, F

2015-01-01

We present the first single-center report of 2 consecutive cases of combined heart and kidney transplantation after insertion of a total artificial heart (TAH). Both patients had advanced heart failure and developed dialysis-dependent renal failure after implantation of the TAH. The 2 patients underwent successful heart and kidney transplantation, with restoration of normal heart and kidney function. On the basis of this limited experience, we consider TAH a safe and feasible option for bridging carefully selected patients with heart and kidney failure to combined heart and kidney transplantation. Recent FDA approval of the Freedom driver may allow outpatient management at substantial cost savings. The TAH, by virtue of its capability of providing pulsatile flow at 6 to 10 L/min, may be the mechanical circulatory support device most likely to recover patients with marginal renal function and advanced heart failure. Copyright © 2015 Elsevier Inc. All rights reserved.

How Heart Valves Evolve to Adapt to an Extreme-Pressure System

DEFF Research Database (Denmark)

Amstrup Funder, Jonas; Christian Danielsen, Carl; Baandrup, Ulrik

2017-01-01

BACKGROUND: Heart valves which exist naturally in an extreme-pressure system must have evolved in a way to resist the stresses of high pressure. Giraffes are interesting as they naturally have a blood pressure twice that of humans. Thus, knowledge regarding giraffe heart valves may aid...... in developing techniques to design improved pressure-resistant biological heart valves. METHODS: Heart valves from 12 giraffes and 10 calves were explanted and subjected to either biomechanical or morphological examinations. Strips from the heart valves were subjected to cyclic loading tests, followed...... in giraffes than in calves, which would make giraffe valves more resistant to the high-pressure forces. However, collagen also stiffens and thickens the valves. The mitral leaflets showed similar (but mostly insignificant) trends in strength, stiffness, and collagen content....

Catheter Entrapment During Posterior Mitral Leaflet Pushing Maneuver for MitraClip Implantation.

Science.gov (United States)

Castrodeza, Javier; Amat-Santos, Ignacio J; Tobar, Javier; Varela-Falcón, Luis H

2016-06-01

MitraClip (Abbott Vascular) therapy has been reported to be an effective procedure for mitral regurgitation, especially in high-risk patients. Recently, the novel pushing maneuver technique has been described for approaching restricted and short posterior leaflets with a pigtail catheter in order to facilitate grasping of the clip. However, complications or unexpected situations may occur. We report the case of an 84-year-old patient who underwent MitraClip implantation wherein the pushing maneuver was complicated by the clip accidentally gripping the pigtail catheter along with the two leaflets.

CERN Heart Days

CERN Multimedia

2003-01-01

14 & 15 OCTOBER 2003 The Medical Service and the Fire Brigade invite everyone working at CERN to participate in the above event. INFIRMARY 9 am to 16.30 pm Building 57, ground floor HEALTHY HEART? ♥ Evaluation of personal cardiac risks through the monitoring of: • Blood pressure • Cholesterol and sugar levels • Body Mass Index ... and more ♥ Leaflets, information and advice concerning cardiac issues FIRE BRIGADE 9 to 12am Building 65 FIRST AID COURSES ♥ What to do in a Cardiac Emergency (3 h duration) Places are limited and on reservation only (15 people / day) To book, E-mail the Medical Services on: service.medical@cern.ch

Efficient replacement of plasma membrane outer leaflet phospholipids and sphingolipids in cells with exogenous lipids.

Science.gov (United States)

Li, Guangtao; Kim, JiHyun; Huang, Zhen; St Clair, Johnna R; Brown, Deborah A; London, Erwin

2016-12-06

Our understanding of membranes and membrane lipid function has lagged far behind that of nucleic acids and proteins, largely because it is difficult to manipulate cellular membrane lipid composition. To help solve this problem, we show that methyl-α-cyclodextrin (MαCD)-catalyzed lipid exchange can be used to maximally replace the sphingolipids and phospholipids in the outer leaflet of the plasma membrane of living mammalian cells with exogenous lipids, including unnatural lipids. In addition, lipid exchange experiments revealed that 70-80% of cell sphingomyelin resided in the plasma membrane outer leaflet; the asymmetry of metabolically active cells was similar to that previously defined for erythrocytes, as judged by outer leaflet lipid composition; and plasma membrane outer leaflet phosphatidylcholine had a significantly lower level of unsaturation than phosphatidylcholine in the remainder of the cell. The data also provided a rough estimate for the total cellular lipids residing in the plasma membrane (about half). In addition to such lipidomics applications, the exchange method should have wide potential for investigations of lipid function and modification of cellular behavior by modification of lipids.

Antithrombin III is associated with acute liver failure in patients with end-stage heart failure undergoing mechanical circulatory support.

Science.gov (United States)

Hoefer, Judith; Ulmer, Hanno; Kilo, Juliane; Margreiter, Raimund; Grimm, Michael; Mair, Peter; Ruttmann, Elfriede

2017-06-01

There are few data on the role of liver dysfunction in patients with end-stage heart failure supported by mechanical circulatory support. The aim of our study was to investigate predictors for acute liver failure in patients with end-stage heart failure undergoing mechanical circulatory support. A consecutive 164 patients with heart failure with New York Heart Association class IV undergoing mechanical circulatory support were investigated for acute liver failure using the King's College criteria. Clinical characteristics of heart failure together with hemodynamic and laboratory values were analyzed by logistic regression. A total of 45 patients (27.4%) with heart failure developed subsequent acute liver failure with a hospital mortality of 88.9%. Duration of heart failure, cause, cardiopulmonary resuscitation, use of vasopressors, central venous pressure, pulmonary capillary wedge pressure, pulmonary pulsatility index, cardiac index, and transaminases were not significantly associated with acute liver failure. Repeated decompensation, atrial fibrillation (P failure in univariate analysis only. In multivariable analysis, decreased antithrombin III was the strongest single measurement indicating acute liver failure (relative risk per %, 0.84; 95% confidence interval, 0.77-0.93; P = .001) and remained an independent predictor when adjustment for the Model for End-Stage Liver Disease score was performed (relative risk per %, 0.89; 95% confidence interval, 0.80-0.99; P = .031). Antithrombin III less than 59.5% was identified as a cutoff value to predict acute liver failure with a corresponding sensitivity of 81% and specificity of 87%. In addition to the Model for End-Stage Liver Disease score, decreased antithrombin III activity tends to be superior in predicting acute liver failure compared with traditionally thought predictors. Antithrombin III measurement may help to identify patients more precisely who are developing acute liver failure during mechanical

[Communication prostheses and behavioral alignment in hospital leaflets].

Science.gov (United States)

Vasconcellos-Silva, Paulo Roberto; Rivera, Francisco Javier Uribe; Rozemberg, Brani

2003-08-01

Review was made of publications that describe experience with printed material distributed to the lay public in hospital institutions. From the 146 leaflets examined, those aimed at professionals or disabled people, thus leaving 75 papers that illustrate the present pattern for the rationality behind the production, use and evaluation of this type of resource. In a general manner, such leaflets invest in the power of "ideal printed information" to align behavior with the hospital's biomedical agenda. The underlying rationality that permeates them perceives the "perfect information package" as one that efficiently describes its technical content for the purpose of unidirectional persuasion, is up-to-date in relation to readability scales and embellished by graphic design, and emphasizes the priorities defined by the professionals. Such "communication prostheses" should be capable of electronic validation by means of software suitable for proportioning the "doses" to the subject matter. Information as a drug, cognitivism, the lack of research on message reception and the need for communicative action for the deconstruction of systems of closed thinking within the hospital environment have been discussed.

A scanning electron microscopy study of the invasion of leaflets of a bloat-safe and a bloat-causing legume by rumen microorganisms.

Science.gov (United States)

Fay, J P; Cheng, K J; Hanna, M R; Howarth, R E; Costerton, J W

1981-04-01

A newly developed technique using ruthenium red to detect foci of bacterial digestion in mounts of whole leaflets that had been incubated with rumen bacteria was used to compare the digestion of alfalfa, a bloat-causing legume, and sainfoin, a bloat-safe legume. When whole leaflets were suspended in an artificial rumen medium and inoculated with rumen bacteria, massive bacterial adhesion and proliferation were noted at the stomata of alfalfa leaflets after 6 h of incubation, whereas only a few isolated bacteria adhered near the stomata of sainfoin leaflets After 22 h of incubation, the epidermal layers of alfalfa leaflets had peeled away in many areas, revealing an extensive bacterial invasion of the underlying mesophyll tissue in which large bacterial microcolonies had formed in intercellular spaces, and in intracellular spaces in several areas where plant cell walls had broken down. After 22 h of incubation, the surface of sainfoin leaflets resembled that of alfalfa leaflets at 6 h, with bacterial microcolonies adhering to the area surrounding the stomata, but without sloughing of the epidermis. Uninoculated control leaflets of both species showed no surface alteration but part of their normal bacterial flora had proliferated to form microcolonies on the surface after 22 h incubation. Dry matter loss due to leaching or bacterial digestion when whole leaflets of legumes were suspended in an artificial rumen medium, alone or with rumen bacteria, was significantly higher in the bloat-causing group. Values of leaching and of bacterial digestion were positively correlated. We conclude that reported differences in plant anatomy, and in cell wall chemistry, produce distinct rates or organic nutrient release from legume leaflets, and that these same differences produce an equally distinct susceptibility of leaflets to bacterial invasion, plant cell rupture, and the consequent release of intracellular plant components. The rate of release of organic nutrients from legume

Mechanisms for altered carnitine content in hypertrophied rat hearts

International Nuclear Information System (INIS)

Reibel, D.K.; O'Rourke, B.; Foster, K.A.

1987-01-01

Carnitine levels are reduced in hypertrophied hearts of rats subjected to aortic constriction (banding) and evaluated in hypertrophied hearts of spontaneously hypertensive rats (SHR). In an attempt to determine the mechanisms for these alterations, L-[ 14 C]carnitine transport was examined in isolated perfused hearts. Total carnitine uptake was significantly reduced by ∼20% in hypertrophied hearts of banded rats at all perfusate carnitine concentrations employed. The reduction in total uptake was due to a 40% reduction in carrier-mediated carnitine uptake with no difference in uptake by diffusion. In contrast, carnitine uptake was not altered in isolated hypertrophied hearts of SHR. However, serum carnitine levels were elevated in SHR, which could result in increased myocardial carnitine uptake in vivo. The data suggest that altered carnitine content in hypertrophied hearts of aortic-banded rats is due to an alteration in the carrier-mediated carnitine transport system in the myocardium. However, altered carnitine content in hypertrophied hearts of SHR is not due to a change in the carnitine transport system per se but may rather be due to a change in serum carnitine levels

Hydrothermal Pretreatment of Date Palm (Phoenix dactylifera L. Leaflets and Rachis to Enhance Enzymatic Digestibility and Bioethanol Potential

Directory of Open Access Journals (Sweden)

Chuanji Fang

2015-01-01

Full Text Available Date palm residues are one of the most promising lignocellulosic biomass for bioethanol production in the Middle East. In this study, leaflets and rachis were subjected to hydrothermal pretreatment to overcome the recalcitrance of the biomass for enzymatic conversion. Evident morphological, structural, and chemical changes were observed by scanning electron microscopy, X-ray diffraction, and infrared spectroscopy after pretreatment. High glucan (>90% for both leaflets and rachis and xylan (>75% for leaflets and >79% for rachis recovery were achieved. Under the optimal condition of hydrothermal pretreatment (210°C/10 min highly digestible (glucan convertibility, 100% to leaflets, 78% to rachis and fermentable (ethanol yield, 96% to leaflets, 80% to rachis solid fractions were obtained. Fermentability test of the liquid fractions proved that no considerable inhibitors to Saccharomyces cerevisiae were produced in hydrothermal pretreatment. Given the high sugar recovery, enzymatic digestibility, and ethanol yield, production of bioethanol by hydrothermal pretreatment could be a promising way of valorization of date palm residues in this region.

Evolution of Mitral Valve Prolapse: Insights From the Framingham Heart Study.

Science.gov (United States)

Delling, Francesca N; Rong, Jian; Larson, Martin G; Lehman, Birgitta; Fuller, Deborah; Osypiuk, Ewa; Stantchev, Plamen; Hackman, Brianne; Manning, Warren J; Benjamin, Emelia J; Levine, Robert A; Vasan, Ramachandran S

2016-04-26

Longitudinal studies of mitral valve prolapse (MVP) progression among unselected individuals in the community, including those with nondiagnostic MVP morphologies (NDMs), are lacking. We measured longitudinal changes in annular diameter, leaflet displacement, thickness, anterior/posterior leaflet projections onto the annulus, coaptation height, and mitral regurgitation jet height in 261 Framingham Offspring participants at examination 5 who had available follow-up imaging 3 to 16 years later. Study participants included MVP (n=63); NDMs, minimal systolic displacement (n=50) and the abnormal anterior coaptation phenotype (n=10, with coaptation height >40% of the annulus similar to posterior MVP); plus 138 healthy referents without MVP or NDMs. At follow-up, individuals with MVP (52% women, 57±11 years) had greater increases of leaflet displacement, thickness, and jet height than referents (all PMVP (17%) had moderate or more severe mitral regurgitation (jet height ≥5 mm) and 5 others (8%) underwent mitral valve repair. Of the individuals with NDM, 8 (80%) participants with abnormal anterior coaptation progressed to posterior MVP; 17 (34%) subjects with minimal systolic displacement were reclassified as either posterior MVP (12) or abnormal anterior coaptation (5). In comparison with the 33 participants with minimal systolic displacement who did not progress, the 17 who progressed had greater leaflet displacement, thickness, coaptation height, and mitral regurgitation jet height (all PMVP, highlighting the clinical significance of mild MVP expression. MVP progresses to significant mitral regurgitation over a period of 3 to 16 years in one-fourth of individuals in the community. Changes in mitral leaflet morphology are associated with both NDM and MVP progression. © 2016 American Heart Association, Inc.

Readability Analysis of the Package Leaflets for Biological Medicines Available on the Internet Between 2007 and 2013: An Analytical Longitudinal Study.

Science.gov (United States)

Piñero-López, María Ángeles; Modamio, Pilar; Lastra, Cecilia F; Mariño, Eduardo L

2016-05-25

The package leaflet included in the packaging of all medicinal products plays an important role in the transmission of medicine-related information to patients. Therefore, in 2009, the European Commission published readability guidelines to try to ensure that the information contained in the package leaflet is understood by patients. The main objective of this study was to calculate and compare the readability levels and length (number of words) of the package leaflets for biological medicines in 2007, 2010, and 2013. The sample of this study included 36 biological medicine package leaflets that were downloaded from the European Medicines Agency website in three different years: 2007, 2010, and 2013. The readability of the selected package leaflets was obtained using the following readability formulas: SMOG grade, Flesch-Kincaid grade level, and Szigriszt's perspicuity index. The length (number of words) of the package leaflets was also measured. Afterwards, the relationship between these quantitative variables (three readability indexes and length) and categorical (or qualitative) variables were analyzed. The categorical variables were the year when the package leaflet was downloaded, the package leaflet section, type of medicine, year of authorization of biological medicine, and marketing authorization holder. The readability values of all the package leaflets exceeded the sixth-grade reading level, which is the recommended value for health-related written materials. No statistically significant differences were found between the three years of study in the readability indexes, although differences were observed in the case of the length (P=.002), which increased over the study period. When the relationship between readability indexes and length and the other variables was analyzed, statistically significant differences were found between package leaflet sections (Preadability indexes (SMOG grade and Flesch-Kincaid grade level: r(2)=.92; SMOG grade and Szigriszt

Consumer's Perception on Design and Layout of Consumer Medical Information Leaflets on Obesity and Lipid Lowering Drugs.

Science.gov (United States)

Mathew, Elizabeth M; Rajiah, Kingston; Sharma, Krishana Kumar

2013-12-01

Printed education materials are often used to augment healthcare professional's verbal information to consumers so it serves as an important component of symptom management. They also enhance the teaching process and can be used by consumers as a home reference. This study was aimed to interpret consumers' perception on Consumer Medical Information Leaflets (CMILs) on obesity and lipid lowering drugs, on design and layout using the standard method such as Baker Able Leaflet Design (BALD). Convenience sampling was done. The study was conducted over a period of 3 years in community pharmacy settings in Tamil Nadu, India. The Consumer Medical Information Leaflets (CMILs) were randomly collected from different community pharmacies. Total of 19 CMILs which are commonly used by the consumers were collected and CMILs were assessed using BALD assessment tool Results: According to BALD assessment (46.28%) leaflets were rated as 'above standard' and (53.72) leaflets were rated as 'standard or poor' in layout and design since their scores were less than 25. This shows that this issue may be important from the patient's perspective, which may discourage patient from actually reading the CMILs. In India, generally CMILs are continued to be prepared in English and with higher proportion of consumers with English illiteracy. CMILs, which are prepared without taking consideration of reading level of consumers and proper layout and design, may not achieve the intended purpose. This is an important aspect that any company has to reckon while preparing leaflets and at least in some major local languages in which CMILs have to be prepared.

PERAN PENYULUHAN DENGAN MENGGUNAKAN LEAFLET TERHADAP PERUBAHAN PENGETAHUAN DAN SIKAP IBU BALITA GIZI KURANG

Directory of Open Access Journals (Sweden)

Salimar Salimar

2012-11-01

Full Text Available ABSTRACT Background: Nutrition extension is one of the approach efforts to increase knowledge in order to gain good behavior. Through this extension, we expected mother of under five years child would understood and comprehended as well as had a willing and could implement what she was advised, so that she could took care of under five years child with underweight nutrition to become better nutrition. Purpose: To study about the changing of knowledge and attitude of mother with undernourished of under-five years child after got intervention of extension for 3 months of between two groups got leaflet and didn't get leaflet. Methods: This applied research applied quasi experiment research design. Population is mother having undernourished of under five years child and mother age ranges from 18-45 years, totally 176 samples. Group of treatment got extension package for 3 months and given leaflet to be studied in house. Group of control was participated extension package for 3 months, but they weren’t given leaflet, and leaflet was given after this research completed. Results: After followed extension package during 3 months, samples showed improvement for mother’s knowledge as 11.4% in group of treatment and 10.4% in group of control. Statististically by using Chi quadrate test, there were a significance difference (p=0.00 for mother’s knowledge before and after research in both group of research. There is a changing for mother’s attitude in group of treatment as 28.1% and 16.1% in group of control. By using chi square test we found significance difference (p=0,021 on mother’s attitude in group of treatment before and after extension for 3 month, while in group of control there was no significance difference ( p=0.187. Conclusions: Leaflet is one of the supporting facilities which applicable to change knowledge and attitude of mother. There is no difference of mother’s motivation in participating this research. The role of husband and

Radiation-induced heart disease due to intrathonacic tumor radiotherapy of a single dose to the rabbits' heart

International Nuclear Information System (INIS)

Zhou Weibing; Feng Yan; Chen Jiayi; Luo Quanyong

2007-01-01

Objective: To observe the changes of radiation-induced heart disease (RIHD) in the rabbits irradiated in clinical related dose, and to evaluate the apoptosis and hypoxia in the irradiated heart by the new scintigraphic agents of 99 Tc m -HL91 and 99 Tc m -Annexin V of heart SPECT. Methods: Tenty-four New Zealand white rabbits 4-month old and 2-3 kg by weight were divided into two groups. Group 1 (clinical related dose group): 16 irradiated by a single close from 0 to 18 Gy. Group 2 (high dose group): 8 irradiated dose from 22 to 80 Gy. The serum cTnI/CKMB, ECG, and heart SPECT(using 99 Tc m -MIBI, 99 Tc m -HL91 and 99 Tc m -Annexin V as agents) were detected before and after irradiation. The animals were followed for 5 months. Then biopsy of rabbit heart was performed and pathologic examination was made by H.E. stain. Results: In the 16 rabbits of clinical related dose group, none died of RIHD. Whereas 2 rabbits died of RIHD in the high dose group. One died of myocardial infarction and the other of congestive heart failure. According to the Stewart introduced heart lesion grading system, of the clinical close ann, there were moderate in 1 rabbit, minimal in 14; and of the high dose ann, it was severe in 2, marked in 1, moderate in 5. The parallel relation was observed between the ECG results and the pathological changes (χ 2 =0.08, P=0.771). Serum value of cTnI, was elevated at the 12th hour after irradiation reaching the peak and maintained for 4 months. However, it came down in the 5th month. The difference of serum cTnI value before and after radiation was statistically significant. Myocardial perfusion scintigraphy tested by heart SPECT ( 99 Tc m -MIBI) showed defects was present in all irradiated rabbits. The relationship between the defects and radiation dose or between the defects and the real RIHD was uncertain. The SPECT images displayed that 99 Tc m -HL91 and 99m Tc-Annexin V did not accumulate in the irradiated heart. Conclusions: No serious damage is

CERN Heart Days

CERN Multimedia

2003-01-01

14 & 15 OCTOBER 2003 The Medical Service and the Fire Brigade invite everyone working at CERN to participate in the above event. INFIRMARY 9 am to 16.30 pm Building 57, ground floor No need to book HEALTHY HEART? Evaluation of personal cardiac risks through the monitoring of: Blood pressure Cholesterol and sugar levels Body Mass Index ... and more Leaflets, information and advice concerning cardiac issues FIRE BRIGADE 9 to 12am - Building 65 Please book (limited to 15 people/day) FIRST AID COURSES What to do in a Cardiac Emergency (3 h. duration) Places are limited and on reservation only (15 people/day). To book, e-mail the Medical Services on: service.medical@cern.ch

CERN Heart Days

CERN Multimedia

2003-01-01

14 & 15 OCTOBER 2003 The Medical Service and the Fire Brigade invite everyone working at CERN to participate in the above event. INFIRMARY 9 am to 16.30 pm Building 57, ground floor no need to book HEALTHY HEART? • Evaluation of personal cardiac risks through the monitoring of: Blood pressure Cholesterol and sugar levels Body Mass Index ... and more • Leaflets, information and advice concerning cardiac issues FIRE BRIGADE 9 to 12 am - Building 65 Please book (limited to 15 people/day) FIRST AID COURSES • What to do in a Cardiac Emergency (3 h. duration) Places are limited and on reservation only (15 people/day). To book, e-mail the Medical Services on: service.medical@cern.ch

Effects of suture position on left ventricular fluid mechanics under mitral valve edge-to-edge repair.

Science.gov (United States)

Du, Dongxing; Jiang, Song; Wang, Ze; Hu, Yingying; He, Zhaoming

2014-01-01

Mitral valve (MV) edge-to-edge repair (ETER) is a surgical procedure for the correction of mitral valve regurgitation by suturing the free edge of the leaflets. The leaflets are often sutured at three different positions: central, lateral and commissural portions. To study the effects of position of suture on left ventricular (LV) fluid mechanics under mitral valve ETER, a parametric model of MV-LV system during diastole was developed. The distribution and development of vortex and atrio-ventricular pressure under different suture position were investigated. Results show that the MV sutured at central and lateral in ETER creates two vortex rings around two jets, compared with single vortex ring around one jet of the MV sutured at commissure. Smaller total orifices lead to a higher pressure difference across the atrio-ventricular leaflets in diastole. The central suture generates smaller wall shear stresses than the lateral suture, while the commissural suture generated the minimum wall shear stresses in ETER.

A New Animal Model for Investigation of Mechanical Unloading in Hypertrophic and Failing Hearts: Combination of Transverse Aortic Constriction and Heterotopic Heart Transplantation.

Directory of Open Access Journals (Sweden)

Andreas Schaefer

Full Text Available Previous small animal models for simulation of mechanical unloading are solely performed in healthy or infarcted hearts, not representing the pathophysiology of hypertrophic and dilated hearts emerging in heart failure patients. In this article, we present a new and economic small animal model to investigate mechanical unloading in hypertrophic and failing hearts: the combination of transverse aortic constriction (TAC and heterotopic heart transplantation (hHTx in rats.To induce cardiac hypertrophy and failure in rat hearts, three-week old rats underwent TAC procedure. Three and six weeks after TAC, hHTx with hypertrophic and failing hearts in Lewis rats was performed to induce mechanical unloading. After 14 days of mechanical unloading animals were euthanatized and grafts were explanted for further investigations.50 TAC procedures were performed with a survival of 92% (46/50. When compared to healthy rats left ventricular surface decreased to 5.8±1.0 mm² (vs. 9.6± 2.4 mm² (p = 0.001 after three weeks with a fractional shortening (FS of 23.7± 4.3% vs. 28.2± 1.5% (p = 0.01. Six weeks later, systolic function decreased to 17.1± 3.2% vs. 28.2± 1.5% (p = 0.0001 and left ventricular inner surface increased to 19.9±1.1 mm² (p = 0.0001. Intraoperative graft survival during hHTx was 80% with 46 performed procedures (37/46. All transplanted organs survived two weeks of mechanical unloading.Combination of TAC and hHTx in rats offers an economic and reproducible small animal model enabling serial examination of mechanical unloading in a truly hypertrophic and failing heart, representing the typical pressure overloaded and dilated LV, occurring in patients with moderate to severe heart failure.

The effectiveness of a pregnancy leaflet to promote health in ...

African Journals Online (AJOL)

2014-11-21

Nov 21, 2014 ... Method: The research design used was a pre-test post-test design. Two samples of 30 ... Self-report data were gathered with a questionnaire based on the leaflet. ..... scenarios for young adults, whether or not they are infected.

Information meeting on the AD leaflets of the HP series

International Nuclear Information System (INIS)

1976-05-01

The present brochure contains discussions and summaries of papers from an information meeting on new leaflets issued by the Arbeitsgemeinschaft Druckbehaelter, Reihe Herstellung und Pruefung (task group pressure vessels, production and testing section), organized by the TUEV of Bavaria. (RW) [de

Development of Prescription Drug Information Leaflets: Impact of Cognitive Effort and Patient Involvement on Prescription Medication Information Processing.

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Patel, Harshali K; Bapat, Shweta S; Bhansali, Archita H; Sansgiry, Sujit S

2018-01-01

The objective of this study was to develop a one-page (1-page) prescription drug information leaflet (PILs) and assess their impact on the information processing variables, across 2 levels of patient involvement. One-page PILs were developed using cognitive principles to lower mental effort and improve comprehension. An experimental, 3 × 2 repeated measures study was conducted to determine the impact of cognitive effort, manipulated using leaflet type on comprehension across 2 levels (high/low) of patient involvement. Adults (≥18 years) in a university setting in Houston were recruited for the study. Each participant was exposed to 3 different types of prescription drug information leaflet (the current practice, preexisting 1-page text-only, and 1-page PILs) for the 3 drugs (Celebrex, Ventolin HFA, Prezista) for a given involvement scenario. A prevalidated survey instrument was used to measure product knowledge, attitude toward leaflet, and intention to read. Multivariate analysis of variance indicated significant positive effect of cognitive effort, involvement, and their interaction effect across all measured variables. Mean scores for product knowledge, attitude toward leaflet, and intention to read were highest for PILs ( P information processing for consumers by reducing their cognitive effort.

A model of mechanical interactions between heart and lungs.

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Fontecave Jallon, Julie; Abdulhay, Enas; Calabrese, Pascale; Baconnier, Pierre; Gumery, Pierre-Yves

2009-12-13

To study the mechanical interactions between heart, lungs and thorax, we propose a mathematical model combining a ventilatory neuromuscular model and a model of the cardiovascular system, as described by Smith et al. (Smith, Chase, Nokes, Shaw & Wake 2004 Med. Eng. Phys.26, 131-139. (doi:10.1016/j.medengphy.2003.10.001)). The respiratory model has been adapted from Thibault et al. (Thibault, Heyer, Benchetrit & Baconnier 2002 Acta Biotheor. 50, 269-279. (doi:10.1023/A:1022616701863)); using a Liénard oscillator, it allows the activity of the respiratory centres, the respiratory muscles and rib cage internal mechanics to be simulated. The minimal haemodynamic system model of Smith includes the heart, as well as the pulmonary and systemic circulation systems. These two modules interact mechanically by means of the pleural pressure, calculated in the mechanical respiratory system, and the intrathoracic blood volume, calculated in the cardiovascular model. The simulation by the proposed model provides results, first, close to experimental data, second, in agreement with the literature results and, finally, highlighting the presence of mechanical cardiorespiratory interactions.

Management of Mechanical Ventilation in Decompensated Heart Failure

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Brooks T. Kuhn

2016-12-01

Full Text Available Mechanical ventilation (MV is a life-saving intervention for respiratory failure, including decompensated congestive heart failure. MV can reduce ventricular preload and afterload, decrease extra-vascular lung water, and decrease the work of breathing in heart failure. The advantages of positive pressure ventilation must be balanced with potential harm from MV: volutrauma, hyperoxia-induced injury, and difficulty assessing readiness for liberation. In this review, we will focus on cardiac, pulmonary, and broader effects of MV on patients with decompensated HF, focusing on practical considerations for management and supporting evidence.

Single living predicts a higher mortality in both women and men with chronic heart failure

DEFF Research Database (Denmark)

Mard, Shan; Nielsen, Finn Erland

2016-01-01

INTRODUCTION: We examined the impact of single living on all-cause mortality in patients with chronic heart failure and determined if this association was modified by gender. METHODS: This historical cohort study included 637 patients who were admitted to the Department of Cardiology, Herlev Hosp......, the risk of death did not differ among single-living women and men. CONCLUSION: Single living is a prognostic determinant of all-cause mortality in men and women with chronic heart failure. FUNDING: none. TRIAL REGISTRATION: not relevant.......INTRODUCTION: We examined the impact of single living on all-cause mortality in patients with chronic heart failure and determined if this association was modified by gender. METHODS: This historical cohort study included 637 patients who were admitted to the Department of Cardiology, Herlev...... for confounding factors. RESULTS: The median follow-up time was 2.8 years. A total of 323 (50.7%) patients died during the follow-up period. After adjustment for confounding factors, risk of death was associated with being single (HR = 1.53 (95% confidence interval: 1.19-1.96)). In a gender-stratified analysis...

Mechanical performance of pyrolytic carbon in prosthetic heart valve applications.

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Cao, H

1996-06-01

An experimental procedure has been developed for rigorous characterization of the fracture resistance and fatigue crack extension in pyrolytic carbon for prosthetic heart valve application. Experiments were conducted under sustained and cyclic loading in a simulated biological environment using Carbomedics Pyrolite carbon. While the material was shown to have modest fracture toughness, it exhibited excellent resistance to subcritical crack growth. The crack growth kinetics in pyrolytic carbon were formulated using a phenomenological description. A fatigue threshold was observed below which the crack growth rate diminishes. A damage tolerance concept based on fracture mechanics was used to develop an engineering design approach for mechanical heart valve prostheses. In particular, a new quantity, referred to as the safe-life index, was introduced to assess the design adequacy against subcritical crack growth in brittle materials. In addition, a weakest-link statistical description of the fracture strength is provided and used in the design of component proof-tests. It is shown that the structural reliability of mechanical heart valves can be assured by combining effective flaw detection and manufacturing quality control with adequate damage tolerance design.

Including patients’ perspectives in patient information leaflets: A polyocular approach

DEFF Research Database (Denmark)

Fage-Butler, Antoinette Mary

2013-01-01

Existing research reveals that patients’ perspectives are missing from mandatory patient information leaflets (PILs). At the same time, there is overwhelming consensus that they should be included in this genre, and a corresponding need for potential approaches to tackle this problem. This paper ...

Home delivery of medication - the role of a patient information leaflet on maximising service uptake.

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Watson, L; Ahmed, N; Mccall, H; Minton, J; Benn, P; Edwards, S; Waters, L

2014-12-01

There are currently over 30,000 HIV-positive individuals in London and over 25,000 on anti-retroviral therapy. In 2009/2010, this equated to £170m spent by London's NHS on anti-retroviral drugs. Ways employed to reduce this cost include standardising the drugs patients are on and delivering medication to patients at home. Home delivery (HD) medication is exempt from value-added tax. The savings made from 10 patients using the home delivery service would free up resources to provide anti-retroviral therapy to one further patient. Studies have shown that concerns surrounding potential breaches of confidentiality are a potential barrier to some people using the home delivery service. In order to challenge these concerns, a leaflet was devised highlighting the major benefits to both the patient and the NHS of home delivery and addressing concerns over confidentiality. The leaflet was handed out to patients at the Mortimer Market Centre who were currently on anti-retroviral medication but not on home delivery. They were asked to complete a survey on their views of the service before and after reading the leaflet, whether they had been previously aware of the service and whether their concerns had been addressed. Some 79% felt that the patient information leaflet addressed all of their concerns, and it helped 11% decide whether to consider using home delivery. However, as more patients were opposed to the service after reading the patient information leaflet than those considering it, more work needs to be done to explore patients' concerns and other factors influencing home delivery service uptake. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Haemodynamic improvement of older, previously replaced mechanical mitral valves by removal of the subvalvular pannus in redo cardiac surgery.

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Kim, Jong Hun; Kim, Tae Youn; Choi, Jong Bum; Kuh, Ja Hong

2017-01-01

Patients requiring redo cardiac surgery for diseased heart valves other than mitral valves may show increased pressure gradients and reduced valve areas of previously placed mechanical mitral valves due to subvalvular pannus formation. We treated four women who had mechanical mitral valves inserted greater than or equal to 20 years earlier and who presented with circular pannus that protruded into the lower margin of the valve ring but did not impede leaflet motion. Pannus removal improved the haemodynamic function of the mitral valve. © The Author 2016. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Draft forces prediction model for standard single tines by using principles of soil mechanics and soil profile evaluation

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Amer Khalid Ahmed Al-Neama

2017-06-01

Full Text Available This paper explains a model to predict the draft force acting on varying standard single tines by using principles of soil mechanics and soil profile evaluation. Draft force (Fd measurements were made with four standard single tines comprising Heavy Duty, Double Heart, Double Heart with Wings and Duck Foot. Tine widths were 6.5, 13.5, 45 and 40 cm, respectively. The test was conducted in a soil bin with sandy loam soil. The effects of forward speeds and working depths on draft forces were investigated under controlled lab conditions. Results were evaluated based on a prediction model. A good correlation between measured and predicted Fd values for all tines with an average absolute variation less than 15 % was found.

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

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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

E-learning or educational leaflet: does it make a difference in oral health promotion? A clustered randomized trial.

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Al Bardaweel, Susan; Dashash, Mayssoon

2018-05-10

The early recognition of technology together with great ability to use computers and smart systems have promoted researchers to investigate the possibilities of utilizing technology for improving health care in children. The aim of this study was to compare between the traditional educational leaflets and E-applications in improving oral health knowledge, oral hygiene and gingival health in schoolchildren of Damascus city, Syria. A clustered randomized controlled trial at two public primary schools was performed. About 220 schoolchildren aged 10-11 years were included in this study and grouped into two clusters. Children in Leaflet cluster received oral health education through leaflets, while children in E-learning cluster received oral health education through an E-learning program. A questionnaire was designed to register information related to oral health knowledge and to record Plaque and Gingival indices. Questionnaire administration and clinical assessment were undertaken at baseline, 6 and at 12 weeks of oral health education. Data was analysed using one way repeated measures ANOVA, post hoc Bonferroni test and independent samples t-test. Leaflet cluster (107 participants) had statistically significant better oral health knowledge than E-learning cluster (104 participants) at 6 weeks (P E-learning cluster:100 participants). The mean knowledge gain compared to baseline was higher in Leaflet cluster than in E-learning cluster. A significant reduction in the PI means at 6 weeks and 12 weeks was observed in both clusters (P E-learning cluster at 6 weeks (P E-learning cluster at 6 weeks (P < 0.05) and 12 weeks (P < 0.05). Traditional educational leaflets are an effective tool in the improvement of both oral health knowledge as well as clinical indices of oral hygiene and care among Syrian children. Leaflets can be used in school-based oral health education for a positive outcome. Australian New Zealand Clinical Trials Registry ( ACTRN

Participants' preference for type of leaflet used to feed back the results of a randomised trial: a survey

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Houston Helen

2010-12-01

Full Text Available Abstract Background Hundreds of thousands of volunteers take part in medical research, but many will never hear from researchers about what the study revealed. There is a growing demand for the results of randomised trials to be fed back to research participants both for ethical research practice and for ensuring their co-operation in a trial. This study aims to determine participants' preferences for type of leaflet (short versus long used to summarise the findings of a randomised trial; and to test whether certain characteristics explained participants' preferences. Methods 553 participants in a randomised trial about General Practitioners' access to Magnetic Resonance Imaging for patients presenting with suspected internal derangement of the knee were asked in the final follow-up questionnaire whether they would like to be fed back the results of the trial. Participants who agreed to this were included in a postal questionnaire survey asking about their preference, if any, between a short and a long leaflet and what it was about the leaflet that they preferred. Multinomial logistic regression was used to test whether certain demographics of responding participants along with treatment group explained whether a participant had a preference for type of leaflet or no preference. Results Of the participants who returned the final follow-up questionnaire, 416 (88% agreed to receive the results of the trial. Subsequently 132 (32% participants responded to the survey. Most participants preferred the longer leaflet (55% and the main reasons for this were the use of technical information (94% and diagrams (89%. There was weak evidence to suggest that gender might explain whether participants have a preference for type of leaflet or not (P = 0.084. Conclusions Trial participants want to receive feed back about the results and appear to prefer a longer leaflet. Males and females might require information to be communicated to them differently and should

Participants' preference for type of leaflet used to feed back the results of a randomised trial: a survey.

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Brealey, Stephen; Andronis, Lazaros; Dennis, Laura; Atwell, Christine; Bryan, Stirling; Coulton, Simon; Cox, Helen; Cross, Ben; Fylan, Fiona; Garratt, Andrew; Gilbert, Fiona; Gillan, Maureen; Hendry, Maggie; Hood, Kerenza; Houston, Helen; King, David; Morton, Veronica; Robling, Michael; Russell, Ian; Wilkinson, Clare

2010-12-01

Hundreds of thousands of volunteers take part in medical research, but many will never hear from researchers about what the study revealed. There is a growing demand for the results of randomised trials to be fed back to research participants both for ethical research practice and for ensuring their co-operation in a trial. This study aims to determine participants' preferences for type of leaflet (short versus long) used to summarise the findings of a randomised trial; and to test whether certain characteristics explained participants' preferences. 553 participants in a randomised trial about General Practitioners' access to Magnetic Resonance Imaging for patients presenting with suspected internal derangement of the knee were asked in the final follow-up questionnaire whether they would like to be fed back the results of the trial. Participants who agreed to this were included in a postal questionnaire survey asking about their preference, if any, between a short and a long leaflet and what it was about the leaflet that they preferred. Multinomial logistic regression was used to test whether certain demographics of responding participants along with treatment group explained whether a participant had a preference for type of leaflet or no preference. Of the participants who returned the final follow-up questionnaire, 416 (88%) agreed to receive the results of the trial. Subsequently 132 (32%) participants responded to the survey. Most participants preferred the longer leaflet (55%) and the main reasons for this were the use of technical information (94%) and diagrams (89%). There was weak evidence to suggest that gender might explain whether participants have a preference for type of leaflet or not (P = 0.084). Trial participants want to receive feed back about the results and appear to prefer a longer leaflet. Males and females might require information to be communicated to them differently and should be the focus of further research. The trial is registered

Consumer’s Perception on Design and Layout of Consumer Medical Information Leaflets on Obesity and Lipid Lowering Drugs

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Mathew, Elizabeth M.; Rajiah, Kingston; Sharma, Krishana Kumar

2013-01-01

Background: Printed education materials are often used to augment healthcare professional’s verbal information to consumers so it serves as an important component of symptom management. They also enhance the teaching process and can be used by consumers as a home reference. Objective: This study was aimed to interpret consumers’ perception on Consumer Medical Information Leaflets (CMILs) on obesity and lipid lowering drugs, on design and layout using the standard method such as Baker Able Leaflet Design (BALD). Material and Methods: Convenience sampling was done. The study was conducted over a period of 3 years in community pharmacy settings in Tamil Nadu, India. The Consumer Medical Information Leaflets (CMILs) were randomly collected from different community pharmacies. Total of 19 CMILs which are commonly used by the consumers were collected and CMILs were assessed using BALD assessment tool Results: According to BALD assessment (46.28%) leaflets were rated as ‘above standard’ and (53.72) leaflets were rated as ‘standard or poor’ in layout and design since their scores were less than 25. This shows that this issue may be important from the patient’s perspective, which may discourage patient from actually reading the CMILs. Conclusion: In India, generally CMILs are continued to be prepared in English and with higher proportion of consumers with English illiteracy. CMILs, which are prepared without taking consideration of reading level of consumers and proper layout and design, may not achieve the intended purpose. This is an important aspect that any company has to reckon while preparing leaflets and at least in some major local languages in which CMILs have to be prepared. PMID:24551641

Direct type gerbode defect with cleft in anterior mitral leaflet: A rarest of rare combination

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Rakesh Jain

2016-01-01

Full Text Available A 15-year-old boy was evaluated for the new onset of dyspnea. He had no significant medical or surgical history. On echocardiography, he was found to have a direct communication between the left ventricle and the right atrium through the atrioventricular (AV septum (a rare type of Gerbode defect with an associated cleft in the anterior mitral leaflet. The combination of direct type Gerbode defect with the cleft of the anterior mitral leaflet is extremely rare.

Wikis to facilitate patient participation in developing information leaflets: first experiences

NARCIS (Netherlands)

Belt, T.H. van de; Faber, M.J.; Knijnenburg, J.M.; Duijnhoven, N.T.L. van; Nelen, W.L.D.M.; Kremer, J.A.M.

2014-01-01

OBJECTIVE: Although patients have gained a wealth of experienced based knowledge they are usually not involved in the development of patient information. We sought to determine the technical feasibility of wikis in generating dynamic patient information leaflets with participation from patients and

[Present status and trend of heart fluid mechanics research based on medical image analysis].

Science.gov (United States)

Gan, Jianhong; Yin, Lixue; Xie, Shenghua; Li, Wenhua; Lu, Jing; Luo, Anguo

2014-06-01

With introduction of current main methods for heart fluid mechanics researches, we studied the characteristics and weakness for three primary analysis methods based on magnetic resonance imaging, color Doppler ultrasound and grayscale ultrasound image, respectively. It is pointed out that particle image velocity (PIV), speckle tracking and block match have the same nature, and three algorithms all adopt block correlation. The further analysis shows that, with the development of information technology and sensor, the research for cardiac function and fluid mechanics will focus on energy transfer process of heart fluid, characteristics of Chamber wall related to blood fluid and Fluid-structure interaction in the future heart fluid mechanics fields.

The enigmatic fast leaflet rotation in Desmodium motorium: butterfly mimicry for defense?

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Lev-Yadun, Simcha

2013-06-01

I propose that the enigmatic leaflet movements in elliptical circles every few minutes of the Indian telegraph (semaphore) plant Desmodium motorium ( = D. gyrans = Hedysarum gyrans = Codariocalyx motorius), which has intrigued scientists for centuries, is a new type of butterfly or general winged arthropod mimicry by this plant. Such leaflet movement may deceive a passing butterfly searching for an un-occupied site suitable to deposit its eggs, that the plant is already occupied. It may also attract insectivorous birds, reptiles or arthropods to the plant because it looks as if it is harboring a potential prey and while they patrol there, they can find insects or other invertebrates that indeed attack the plant. The possibility that diurnal mammalian herbivores may also be deterred by these movements should not be dismissed.

A single dose of dark chocolate increases parasympathetic modulation and heart rate variability in healthy subjects

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Ana Amélia Machado DUARTE

Full Text Available ABSTRACT Objective: The aim of this study was to investigate the acute effect of a single dose of dark chocolate (70% cocoa on blood pressure and heart rate variability. Methods: Thirty-one healthy subjects (aged 18-25 years; both sexes were divided into two groups: 10 subjects in the white chocolate (7.4 g group and 21 in the dark chocolate (10 g group; measurements were performed at the university's physiology lab. An electrocardiogram measured the sympathovagal balance by spectral and symbolic analysis. Results: A single dose of dark chocolate significantly reduced systolic blood pressure and heart rate. After consuming 10 g of dark chocolate, significant increases were observed for heart rate variability, standard deviation of RR intervals standard deviation of all NN intervals, square root of the mean squared differences between adjacent normal RR intervals root mean square of successive differences, and an increase in the high frequency component in absolute values, representing the parasympathetic modulation. Conclusion: In conclusion the importance of our results lies in the magnitude of the response provoked by a single dose of cocoa. Just 10 g of cocoa triggered a significant increase in parasympathetic modulation and heart rate variability. These combined effects can potentially increase life expectancy because a reduction in heart rate variability is associated with several cardiovascular diseases and higher mortality.

A single-item self-report medication adherence question predicts hospitalisation and death in patients with heart failure.

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Wu, Jia-Rong; DeWalt, Darren A; Baker, David W; Schillinger, Dean; Ruo, Bernice; Bibbins-Domingo, Kristen; Macabasco-O'Connell, Aurelia; Holmes, George M; Broucksou, Kimberly A; Erman, Brian; Hawk, Victoria; Cene, Crystal W; Jones, Christine DeLong; Pignone, Michael

2014-09-01

To determine whether a single-item self-report medication adherence question predicts hospitalisation and death in patients with heart failure. Poor medication adherence is associated with increased morbidity and mortality. Having a simple means of identifying suboptimal medication adherence could help identify at-risk patients for interventions. We performed a prospective cohort study in 592 participants with heart failure within a four-site randomised trial. Self-report medication adherence was assessed at baseline using a single-item question: 'Over the past seven days, how many times did you miss a dose of any of your heart medication?' Participants who reported no missing doses were defined as fully adherent, and those missing more than one dose were considered less than fully adherent. The primary outcome was combined all-cause hospitalisation or death over one year and the secondary endpoint was heart failure hospitalisation. Outcomes were assessed with blinded chart reviews, and heart failure outcomes were determined by a blinded adjudication committee. We used negative binomial regression to examine the relationship between medication adherence and outcomes. Fifty-two percent of participants were 52% male, mean age was 61 years, and 31% were of New York Heart Association class III/IV at enrolment; 72% of participants reported full adherence to their heart medicine at baseline. Participants with full medication adherence had a lower rate of all-cause hospitalisation and death (0·71 events/year) compared with those with any nonadherence (0·86 events/year): adjusted-for-site incidence rate ratio was 0·83, fully adjusted incidence rate ratio 0·68. Incidence rate ratios were similar for heart failure hospitalisations. A single medication adherence question at baseline predicts hospitalisation and death over one year in heart failure patients. Medication adherence is associated with all-cause and heart failure-related hospitalisation and death in heart

Heart failure with preserved ejection fraction: mechanisms, clinical features, and therapies.

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Sharma, Kavita; Kass, David A

2014-06-20

The clinical syndrome comprising heart failure (HF) symptoms but with a left ventricular ejection fraction (EF) that is not diminished, eg, HF with preserved EF, is increasingly the predominant form of HF in the developed world, and soon to reach epidemic proportions. It remains among the most challenging of clinical syndromes for the practicing clinician and scientist alike, with a multitude of proposed mechanisms involving the heart and other organs and complex interplay with common comorbidities. Importantly, its morbidity and mortality are on par with HF with reduced EF, and as the list of failed treatments continues to grow, HF with preserved EF clearly represents a major unmet medical need. The field is greatly in need of a more unified approach to its definition and view of the syndrome that engages integrative and reserve pathophysiology beyond that related to the heart alone. We need to reflect on prior treatment failures and the message this is providing, and redirect our approaches likely with a paradigm shift in how the disease is viewed. Success will require interactions between clinicians, translational researchers, and basic physiologists. Here, we review recent translational and clinical research into HF with preserved EF and give perspectives on its evolving demographics and epidemiology, the role of multiorgan deficiencies, potential mechanisms that involve the heart and other organs, clinical trials, and future directions. © 2014 American Heart Association, Inc.

Evaluation of single right atrial volume and function with magnetic resonance imaging in children with hypoplastic left heart

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Vijarnsorn, Chodchanok [University of Alberta, Faculty of Medicine and Dentistry, Stollery Children' s Hospital, Edmonton, AB (Canada); Mahidol University, Siriraj Hospital, Bangkok (Thailand); Myers, Kimberley; Patton, David J. [Alberta Children' s Hospital, Section of Pediatric Cardiology, Department of Pediatrics, Department of Pediatrics, Calgary, AB (Canada); Noga, Michelle; Crawley, Cinzia; Tham, Edythe [University of Alberta, Faculty of Medicine and Dentistry, Stollery Children' s Hospital, Edmonton, AB (Canada)

2016-06-15

Standardized methods to evaluate atrial properties in single ventricles are lacking. To determine the feasibility of quantifying right atrial volumes and function in hypoplastic left heart using MRI. We studied 15 infants with hypoplastic left heart prior to Glenn surgery (mean age 4.2 months [standard deviation 0.3]) who underwent cardiac MRI with evaluation of atrial volumes and emptying fraction using monoplane two-chamber, monoplane four-chamber, and biplane methods, all of which were compared to the atrial short-axial oblique stack method. We compared atrial end-diastolic volume, end-systolic volume and emptying fraction among these methods. We analyzed reproducibility of the methods using Bland-Altman plots. Both four-chamber and biplane methods showed high correlations for atrial end-diastolic volume (r = 0.7 and r = 0.8, respectively; P < 0.01) and end-systolic volume (r = 0.8 and r = 0.9, respectively; P < 0.01) with small mean differences (-0.2 ± 2.9 standard deviation [SD] ml and -0.8 ± 1.6 ml, respectively, for atrial end-diastolic volume and -0.8 ± 1.5 ml and -0.9 ± 0.9 ml, respectively, for atrial end-systolic volume). The short-axial oblique method was the most reproducible, followed by the four-chamber method. MRI assessment of atrial volume and function is feasible in hypoplastic left heart and might provide further insight into single-ventricle mechanics. (orig.)

The heart as a self-regulating system: integration of homeodynamic mechanisms.

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Kresh, J Y; Armour, J A

1997-04-01

In the past the study of mechanical and electrical properties of the heart has been disjointed with minimal overlap and unification. The fact remains that these features are tightly coupled and central to the functioning heart. The maintenance of adequate cardiac output relies upon the highly integrated autoregulatory mechanisms and modulation of cardiac myocyte function. Regional ventricular mechanics and energetics are dependent upon muscle fiber stress-strain rate, the passive properties of myocardial collagen matrix, adequate vascular perfusion, transcapillary transport and electrical activation pattern. Intramural hydraulic "loading" is regulated by coronary arterial and venous dynamics. All of these components are under the constant influence of intrinsic cardiac and extracardiac autonomic neurons, as well as circulating hormones. A brief overview of the putative regulation of these various components is presented in this paper.

Impact of T-cell-mediated immune response on xenogeneic heart valve transplantation: short-term success and mid-term failure.

Science.gov (United States)

Biermann, Anna C; Marzi, Julia; Brauchle, Eva; Schneider, Maria; Kornberger, Angela; Abdelaziz, Sherif; Wichmann, Julian L; Arendt, Christophe T; Nagel, Eike; Brockbank, Kelvin G M; Seifert, Martina; Schenke-Layland, Katja; Stock, Ulrich A

2018-04-01

Allogeneic frozen cryopreserved heart valves (allografts or homografts) are commonly used in clinical practice. A major obstacle for their application is the limited availability in particular for paediatrics. Allogeneic large animal studies revealed that alternative ice-free cryopreservation (IFC) results in better matrix preservation and reduced immunogenicity. The objective of this study was to evaluate xenogeneic (porcine) compared with allogeneic (ovine) IFC heart valves in a large animal study. IFC xenografts and allografts were transplanted in 12 juvenile merino sheep for 1-12 weeks. Immunohistochemistry, ex vivo computed tomography scans and transforming growth factor-β release profiles were analysed to evaluate postimplantation immunopathology. In addition, near-infrared multiphoton imaging and Raman spectroscopy were employed to evaluate matrix integrity of the leaflets. Acellular leaflets were observed in both groups 1 week after implantation. Allogeneic leaflets remained acellular throughout the entire study. In contrast, xenogeneic valves were infiltrated with abundant T-cells and severely thickened over time. No collagen or elastin changes could be detected in either group using multiphoton imaging. Raman spectroscopy with principal component analysis focusing on matrix-specific peaks confirmed no significant differences for explanted allografts. However, xenografts demonstrated clear matrix changes, enabling detection of distinct inflammatory-driven changes but without variations in the level of transforming growth factor-β. Despite short-term success, mid-term failure of xenogeneic IFC grafts due to a T-cell-mediated extracellular matrix-triggered immune response was shown.

Penggunaan VCD dan Leaflet untuk Peningkatan Pengetahuan, Sikap, dan Perilaku Siswa dalam Pencegahan Kecelakaan Sepeda Motor

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Mulyono Notosiswoyo

2014-04-01

Full Text Available Indonesia belum mempunyai kebijakan penyuluhan pencegahan kecelakaan sepeda motor yang efektif. Tujuan penelitian ini adalah menilai efektivitas penggunaan visual compact disk (VCD dan leaflet terhadap peningkatan pengetahuan, sikap dan perilaku siswa SLTA dalam pencegahan kecelakaan sepeda motor di Kota Bekasi pada tahun 2010. Desain penelitian yang digunakan quasi experiment dengan rancangan equivalent pretest and post-test with control group, dengan intervensi pemutaran VCD dan pemberian leaflet. Sampel dihitung berdasarkan uji 2 proporsi, diperoleh sampel minimal 211 untuk yang di intervensi dan 211 untuk kontrol. Mereka diambil dari siswa SLTA kelas I dan kelas II yang sering mengendarai sepeda motor. Evaluasi hasil intervensi dilakukan setelah tiga bulan. Alat pengumpul data adalah kuesioner yang telah diuji coba. Analisis data menggunakan uji Kolmogorov-Smirnov, uji-t berpasangan dan uji-t independen. Hasil penelitian menunjukan uji-t berpasangan pada kelompok yang di intervensi meningkatkan rerata skor pengetahuan, sikap, dan perilaku siswa SLTA sebelum dibandingkan sesudah pemutaran VCD dan pemberian leaflet bermakna (nilai p < 0,05, tetapi pada kelompok kontrol hanya terjadi peningkatan rerata skor perilaku sebelum dibandingkan sesudah adanya perlakukan. Sedangkan, hasil uji-t independen menunjukan hanya pada rerata skor variabel pengetahuan terdapat perbedaan peningkatan skor antara kelompok intervensi dan kelompok kontrol yang bermakna (nilai p < 0,05. Kesimpulannya, penyuluhan menggunakan VCD dan leaflet dapat meningkatkan pengetahuan siswa SLTA dalam pencegahan kecelakaan sepeda motor. Indonesia does not have a policy of promotion motorcycle accident prevention. The purpose of this study was to assess the effectiveness of the Visual Compact Disks and leaflets to increase in knowledge, attitudes and behavior of the motorcycle accident prevention on high school students in Bekasi City. The method used a non-randomized quasi

Exergames versus self-regulated exercises with instruction leaflets to improve adherence during geriatric rehabilitation: a randomized controlled trial.

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Oesch, Peter; Kool, Jan; Fernandez-Luque, Luis; Brox, Ellen; Evertsen, Gunn; Civit, Anton; Hilfiker, Roger; Bachmann, Stefan

2017-03-23

Improving mobility in elderly persons is a primary goal in geriatric rehabilitation. Self-regulated exercises with instruction leaflets are used to increase training volume but adherence is often low. Exergames may improve adherence. This study therefore compared exergames with self-regulated exercise using instruction leaflets. The primary outcome was adherence. Secondary outcomes were enjoyment, motivation and balance during walking. Design: single center parallel group non-blinded randomized controlled trial with central stratified randomization. center for geriatric inpatient rehabilitation. Included were patients over 65 with mobility restrictions who were able to perform self-regulated exercise. Patients were assigned to self-regulated exercise using a) exergames on Windows Kinect® (exergame group EG) or b) instruction leaflets (conventional group CG). During two 30 min sessions physical therapists instructed self-regulated exercise to be conducted twice daily during thirty minutes during ten working days. Patients reported adherence (primary outcome), enjoyment and motivation daily. Balance during walking was measured blind before and after the treatment phase with an accelerometer. Analysis was by intention to treat. Repeated measures mixed models and Cohen's d effect sizes (ES, moderate if >0.5, large if > 0.8) with 95% CIs were used to evaluate between-group effects over time. Alpha was set at 0.05. From June 2014 to December 2015 217 patients were evaluated and 54 included, 26 in the EG and 28 in the CG. Adverse effects were observed in two patients in the EG who stopped because of pain during exercising. Adherence was comparable at day one (38 min. in the EG and 42 min. in the CG) and significantly higher in the CG at day 10 (54 min. in the CG while decreasing to 28 min. in the EG, p = 0.007, ES 0.94, 0.39-0.151). Benefits favoring the CG were also observed for enjoyment (p = 0.001, ES 0.88, 0.32 - 1.44) and motivation (p = 0

Sharp incision of the anterior mitral leaflet due to penetrating trauma - Report of a case and long-term follow-up

NARCIS (Netherlands)

de Boer, HD; Hamer, HPM; Ebels, T

A case is described of sharp incision of the anterior leaflet of the mitral valve, due to penetrating trauma to the chest with a knife. The lesion of the mitral leaflet was diagnosed with echocardiography and successfully repaired with autologous pericardial tissue. Follow up after 15 years showed

Septal Leaflet versus Chordal Detachment in Closure of Hard-To-Expose Ventricular Septal Defects.

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Pourmoghadam, Kamal K; Boron, Agnieszka; Ruzmetov, Mark; Narasimhulu, Sukumar Suguna; Kube, Alicia; O'Brien, Michael C; DeCampli, William M

2018-04-04

Different techniques have been used for exposure of ventricular septal defect (VSD) margins when there is crowding of the VSD anatomy by tricuspid valve (TV) subvalvar apparatus. The aim of this study was to compare surgical outcomes, for the two techniques of TV leaflet detachment and the rarely described TV chordal detachment for hard-to-expose VSDs. Patients undergoing transatrial VSD repair were identified from our institutional database. Follow-up echocardiography and patient data were obtained from medical records. Between 1/2005-8/2016, 130 isolated conoventricular VSDs were repaired. Among these, 26patients had leaflet detachment, while 15 underwent chordal detachment, and 89 had regular VSD repair (reference group). There was no significant difference between the groups in age, weight, postoperative length-of-stay, genetic/syndromic abnormalities, time-to-extubation, and left and right ventricular systolic function. The cardiopulmonary bypass and cross-clamp time were significantly higher in leaflet detachment group, when compared with reference group (118+28vs102+32, p=0.02; and 73+20vs61+23, p=0.01, respectively). Echocardiographic follow-up were available for 87patients at a mean of 2.6years (1month-11years). Tricuspid regurgitation was rated as none or trivial in 66(76%), mild in 20(23%) and moderate in one reference group patient. There was no difference in presence of residual VSD, or degree of tricuspid regurgitation amongst the three groups. There was no reoperation for tricuspid regurgitation. Tricuspid valve leaflet and chordal detachment techniques provide equally viable and safe alternative to closure of hard-to-expose VSDs while maintaining appropriate TV function. Their use in our series did not lead to increased TV dysfunction at early-to-midterm echocardiographic assessment. Copyright © 2018. Published by Elsevier Inc.

MECHANICAL HEART-VALVE PROSTHESES - SOUND LEVEL AND RELATED COMPLAINTS

NARCIS (Netherlands)

LAURENS, RRP; WIT, HP; EBELS, T

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

Obstructed bi-leaflet prosthetic mitral valve imaging with real-time three-dimensional transesophageal echocardiography.

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Shimbo, Mai; Watanabe, Hiroyuki; Kimura, Shunsuke; Terada, Mai; Iino, Takako; Iino, Kenji; Ito, Hiroshi

2015-01-01

Real-time three-dimensional transesophageal echocardiography (RT3D-TEE) can provide unique visualization and better understanding of the relationship among cardiac structures. Here, we report the case of an 85-year-old woman with an obstructed mitral prosthetic valve diagnosed promptly by RT3D-TEE, which clearly showed a leaflet stuck in the closed position. The opening and closing angles of the valve leaflets measured by RT3D-TEE were compatible with those measured by fluoroscopy. Moreover, RT3D-TEE revealed, in the ring of the prosthetic valve, thrombi that were not visible on fluoroscopy. RT3D-TEE might be a valuable diagnostic technique for prosthetic mitral valve thrombosis. © 2014 Wiley Periodicals, Inc.

Preliminary study of single contrast enhanced dual energy heart imaging using dual-source CT

International Nuclear Information System (INIS)

Peng Jin; Zhang Longjiang; Zhou Changsheng; Lu Guangming; Ma Yan; Gu Haifeng

2009-01-01

Objective: To evaluate the feasibility and preliminary applications of single contrast enhanced dual energy heart imaging using dual-source CT (DSCT). Methods: Thirty patients underwent dual energy heart imaging with DSCT, of which 6 cases underwent SPECT or DSA within one week. Two experienced radiologists assessed image quality of coronary arteries and iodine map of myocardium. and correlated the coronary artery stenosis with the perfusion distribution of iodine map. Results: l00% (300/300) segments reached diagnostic standards. The mean score of image for all patients was 4.68±0.57. Mural coronary artery was present in 10 segments in S cases, atherosclerotic plaques in 32 segments in 12 cases, of which 20 segments having ≥50% stenosis, 12 segments ≤50% stenosis; dual energy CT coronary angiography was consistent with the DSA in 3 patients. 37 segmental perfusion abnormalities on iodine map were found in 15 cases, including 28 coronary blood supply segment narrow segment and 9 no coronary stenosis (including three negative segments in SPECD. Conclusion: Single contrast enhanced dual energy heart imaging can provide good coronary artery and myocardium perfusion images in the patients with appropriate heart rate, which has a potential to be used in the clinic and further studies are needed. (authors)

Embolization of Collateral Vessels Using Mechanically Detachable Coils in Young Children with Congenital Heart Disease

International Nuclear Information System (INIS)

Sato, Y.; Ogino, H.; Hara, M.; Satake, M.; Oshima, H.; Banno, T.; Mizuno, K.; Mishima, A.; Shibamoto, Y.

2003-01-01

Our objective was to evaluate the usefulness of embolizing collateral vessels using mechanically detachable coils (MDCs) in children aged 3 years or younger with congenital heart disease. The subjects were 8 children with congenital heart disease featuring collateral vessels (age 18 days-3 years): 3 with a single ventricle, 2 with the tetralogy of Fallot, 2 with pulmonary atresia, and 1 with a ventricular septal defect. The embolized vessels were the major aortopulmonary collateral artery (MAPCA) in 5 patients, the persistent left superior vena cava in 2, and the coronary arteriovenous fistula in 1. A 4 or a 5 F catheter was used as the guiding device, and embolization was performed using MDCs and other conventional coils introduced through the microcatheter. One patient had growth of new MAPCAs after embolization, and these MAPCAs were also embolized with MDCs. Thus, a total of 9 embolization procedures were performed in 8 patients. Complete occlusion of the collateral vessels was achieved in 8 of 9 procedures (89%). Seven of 8 patients (88%) had uneventful courses after embolization, and MDC procedures appeared to play important roles in avoiding coil migration and achievement of safe coil embolization. One patient who underwent MAPCA embolization showed no improvement in heart function and died 2 months and 19 days later. Embolization of collateral vessels using MDCs in young children with congenital heart disease can be an effective procedure and a valuable adjunct to surgical management

Mechanical analysis of single myocyte contraction in a 3-D elastic matrix.

Directory of Open Access Journals (Sweden)

John Shaw

Full Text Available Cardiac myocytes experience mechanical stress during each heartbeat. Excessive mechanical stresses under pathological conditions cause functional and structural remodeling that lead to heart diseases, yet the precise mechanisms are still incompletely understood. To study the cellular and molecular level mechanotransduction mechanisms, we developed a new 'cell-in-gel' experimental system to exert multiaxial (3-D stresses on a single myocyte during active contraction.Isolated myocytes are embedded in an elastic hydrogel to simulate the mechanical environment in myocardium (afterload. When electrically stimulated, the in-gel myocyte contracts while the matrix resists shortening and broadening of the cell, exerting normal and shear stresses on the cell. Here we provide a mechanical analysis, based on the Eshelby inclusion problem, of the 3-D strain and stress inside and outside the single myocyte during contraction in an elastic matrix.(1 The fractional shortening of the myocyte depends on the cell's geometric dimensions and the relative stiffness of the cell to the gel. A slender or softer cell has less fractional shortening. A myocyte of typical dimensions embedded in a gel of similar elastic stiffness can contract only 20% of its load-free value. (2 The longitudinal stress inside the cell is about 15 times the transverse stress level. (3 The traction on the cell surface is highly non-uniform, with a maximum near its ends, showing 'hot spots' at the location of intercalated disks. (4 The mechanical energy expenditure of the myocyte increases with the matrix stiffness in a monotonic and nonlinear manner.Our mechanical analyses provide analytic solutions that readily lend themselves to parametric studies. The resulting 3-D mapping of the strain and stress states serve to analyze and interpret ongoing cell-in-gel experiments, and the mathematical model provides an essential tool to decipher and quantify mechanotransduction mechanisms in cardiac

Effect of pretreatment with epoxy compounds on the mechanical properties of bovine pericardial bioprosthetic materials.

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Xi, T; Liu, F; Xi, B

1992-07-01

Early failures of bovine pericardial heart valves are due to leaflet perforation, tearing and calcification. Since glutaraldehyde fixation has been shown to produce marked changes in leaflet mechanics and has been linked to development of calcification, bovine pericardium fixed with the four hydrophilic epoxy formulations and their mechanical properties are studied in this paper. We measured the thicknesses, shrinkage temperatures, stress relaxations and stress-strain curves of bovine pericardiums after different treatments with (1) non-treatment (fresh), (2) glutaraldehyde (GA), (3) epoxy compounds followed by the posttreatment with GA (EP 1#, EP 2#), and (4) epoxy compounds (EP 3# and EP 4#). Results of this study showed that the hydrophilic epoxy compounds are good crosslinking agents. There are no significant differences of shrinkage temperature and ultimate tensile stress among all tissue samples pretreated with GA, EP 1# and EP 2#. However, the stress relaxations of tissue-samples pretreated with epoxy compounds followed by the posttreatment with GA (EP 1# and EP 2#) are significantly slower than that pretreated with GA, and the strains at fracture of EP 1# and EP 2# are also significantly larger than that of GA or epoxy compounds. These facts show that the bovine pericardium pretreated with the epoxy compound followed by the posttreatment with GA (EP 1# and EP 2#) possesses greater tenacity and potential durability in dynamic stress.

The value of an information leaflet for patients having nuclear medicine investigations

International Nuclear Information System (INIS)

Ahmed, Susan Mohamed; Mohammed, Nada Yousif; Elhasseen, Amna Elnour

2001-01-01

This research aimed at design an information leaflet about nuclear medicine investigations usually done at the radiation and isotopes centre of Khartoum (RICK). The objectives are: to confirm lack of knowledge among patients attending hospital, to find out kind of information required and to improve service quality

Detection of cholesterol-rich microdomains in the inner leaflet of the plasma membrane

International Nuclear Information System (INIS)

Hayashi, Masami; Shimada, Yukiko; Inomata, Mitsushi; Ohno-Iwashita, Yoshiko

2006-01-01

The C-terminal domain (D4) of perfringolysin O binds selectively to cholesterol in cholesterol-rich microdomains. To address the issue of whether cholesterol-rich microdomains exist in the inner leaflet of the plasma membrane, we expressed D4 as a fusion protein with EGFP in MEF cells. More than half of the EGFP-D4 expressed in stable cell clones was bound to membranes in raft fractions. Depletion of membrane cholesterol with β-cyclodextrin reduced the amount of EGFP-D4 localized in raft fractions, confirming EGFP-D4 binding to cholesterol-rich microdomains. Subfractionation of the raft fractions showed most of the EGFP-D4 bound to the plasma membrane rather than to intracellular membranes. Taken together, these results strongly suggest the existence of cholesterol-rich microdomains in the inner leaflet of the plasma membrane

Emerging Research Directions in Adult Congenital Heart Disease: A Report from a National Heart, Lung, and Blood Institute/Adult Congenital Heart Association Working Group

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Gurvitz, Michelle; Burns, Kristin M.; Brindis, Ralph; Broberg, Craig S.; Daniels, Curt J.; Fuller, Stephanie M.P.N.; Honein, Margaret A.; Khairy, Paul; Kuehl, Karen S.; Landzberg, Michael J.; Mahle, William T.; Mann, Douglas L.; Marelli, Ariane; Newburger, Jane W.; Pearson, Gail D.; Starling, Randall C.; Tringali, Glenn R.; Valente, Anne Marie; Wu, Joseph C.; Califf, Robert M.

2016-01-01

Congenital heart disease (CHD) is the most common birth defect, affecting about 0.8% of live births. Advances in recent decades have allowed >85% of children with CHD to survive to adulthood, creating a growing population of adults with CHD. Little information exists regarding survival, demographics, late outcomes, and comorbidities in this emerging group, and multiple barriers impede research in adult CHD (ACHD). The National Heart, Lung, and Blood Institute and the Adult Congenital Heart Association convened a multidisciplinary Working Group to identify high-impact research questions in ACHD. This report summarizes the meeting discussions in the broad areas of CHD-related heart failure, vascular disease and multisystem complications. High-priority subtopics identified included heart failure in tetralogy of Fallot, mechanical circulatory support/transplantation, sudden cardiac death, vascular outcomes in coarctation of the aorta, late outcomes in single ventricle disease, cognitive and psychiatric issues, and pregnancy. PMID:27102511

Role of Information Anxiety and Information Load on Processing of Prescription Drug Information Leaflets.

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Bapat, Shweta S; Patel, Harshali K; Sansgiry, Sujit S

2017-10-16

In this study, we evaluate the role of information anxiety and information load on the intention to read information from prescription drug information leaflets (PILs). These PILs were developed based on the principals of information load and consumer information processing. This was an experimental prospective repeated measures study conducted in the United States where 360 (62% response rate) university students (>18 years old) participated. Participants were presented with a scenario followed by exposure to the three drug product information sources used to operationalize information load. The three sources were: (i) current practice; (ii) pre-existing one-page text only; and (iii) interventional one-page prototype PILs designed for the study. Information anxiety was measured as anxiety experienced by the individual when encountering information. The outcome variable of intention to read PILs was defined as the likelihood that the patient will read the information provided in the leaflets. A survey questionnaire was used to capture the data and the objectives were analyzed by performing a repeated measures MANOVA using SAS version 9.3. When compared to current practice and one-page text only leaflets, one-page PILs had significantly lower scores on information anxiety ( p information load ( p Information anxiety and information load significantly impacted intention to read ( p < 0.001). Newly developed PILs increased patient's intention to read and can help in improving the counseling services provided by pharmacists.

Low-dose copper infusion into the coronary circulation induces acute heart failure in diabetic rats: New mechanism of heart disease.

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Cheung, Carlos Chun Ho; Soon, Choong Yee; Chuang, Chia-Lin; Phillips, Anthony R J; Zhang, Shaoping; Cooper, Garth J S

2015-09-01

Diabetes impairs copper (Cu) regulation, causing elevated serum Cu and urinary Cu excretion in patients with established cardiovascular disease; it also causes cardiomyopathy and chronic cardiac impairment linked to defective Cu homeostasis in rats. However, the mechanisms that link impaired Cu regulation to cardiac dysfunction in diabetes are incompletely understood. Chronic treatment with triethylenetetramine (TETA), a Cu²⁺-selective chelator, improves cardiac function in diabetic patients, and in rats with heart disease; the latter displayed ∼3-fold elevations in free Cu²⁺ in the coronary effluent when TETA was infused into their coronary arteries. To further study the nature of defective cardiac Cu regulation in diabetes, we employed an isolated-perfused, working-heart model in which we infused micromolar doses of Cu²⁺ into the coronary arteries and measured acute effects on cardiac function in diabetic and non-diabetic-control rats. Infusion of CuCl₂ solutions caused acute dose-dependent cardiac dysfunction in normal hearts. Several measures of baseline cardiac function were impaired in diabetic hearts, and these defects were exacerbated by low-micromolar Cu²⁺ infusion. The response to infused Cu²⁺ was augmented in diabetic hearts, which became defective at lower infusion levels and underwent complete pump failure (cardiac output = 0 ml/min) more often (P acute effects on cardiac function of pathophysiological elevations in coronary Cu²⁺. The effects of Cu²⁺ infusion occur within minutes in both control and diabetic hearts, which suggests that they are not due to remodelling. Heightened sensitivity to the acute effects of small elevations in Cu²⁺ could contribute substantively to impaired cardiac function in patients with diabetes and is thus identified as a new mechanism of heart disease. Copyright © 2015 Elsevier Inc. All rights reserved.

Meta-analysis of the relationship between single nucleotide polymorphism of IL-10-1082G/A and rheumatic heart disease.

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Dai, Weiran; Ye, Ziliang; Lu, Haili; Su, Qiang; Li, Hui; Li, Lang

2018-02-23

The results showed that there was a certain correlation between the single nucleotide polymorphism of IL-10-1082G/A and rheumatic heart disease, but there was no systematic study to verify this conclusion. Systematic review of the association between single nucleotide polymorphism of IL-10-1082G/A locus and rheumatic heart disease. Computer retrieval PubMed, EMbase, Cochrane Library, CBM, CNKI, VIP and Data WanFang, the retrieval time limit from inception to June 2017. A case control study of single nucleotide polymorphisms and rheumatic heart disease in patients with rheumatic heart disease in the IL-10-1082G/A was collected. Two researchers independently screened the literature, extracted data and evaluated the risk of bias in the study, and using RevMan5.3 software for data analysis. A total of 3 case control studies were included, including 318 patients with rheumatic heart disease and 502 controls. Meta-analysis showed that there was no correlation between IL-10-1082G/A gene polymorphism and rheumatic heart disease [AA+AG VS GG: OR = 0.62, 95% CI (0.28, 1.39), P = 0.25; AA VS AG+GG: OR = 0.73, 95% CI (0.54, 1.00), P = 0.05; AA VS GG: OR = 0.70, 95% CI(0.47, 1.05), P = 0.08; AG VS GG: OR = 0.65, 95% CI (0.22, 1.92), P = 0.43; A VS G: OR = 0.87, 95% CI (0.71, 1.06), P = 0.17]. When AA is a recessive gene, the single nucleotide polymorphism of IL-10-1082G/A is associated with the presence of rheumatic heart disease. Due to the limitations of the quantity and quality of the included literatures, the further research results were still needed.

Genetics of Congenital Heart Disease: Past and Present.

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Muntean, Iolanda; Togănel, Rodica; Benedek, Theodora

2017-04-01

Congenital heart disease is the most common congenital anomaly, representing an important cause of infant morbidity and mortality. Congenital heart disease represents a group of heart anomalies that include septal defects, valve defects, and outflow tract anomalies. The exact genetic, epigenetic, or environmental basis of congenital heart disease remains poorly understood, although the exact mechanism is likely multifactorial. However, the development of new technologies including copy number variants, single-nucleotide polymorphism, next-generation sequencing are accelerating the detection of genetic causes of heart anomalies. Recent studies suggest a role of small non-coding RNAs, micro RNA, in congenital heart disease. The recently described epigenetic factors have also been found to contribute to cardiac morphogenesis. In this review, we present past and recent genetic discoveries in congenital heart disease.

Single living predicts a higher mortality in both women and men with chronic heart failure.

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Mard, Shan; Nielsen, Finn Erland

2016-09-01

We examined the impact of single living on all-cause mortality in patients with chronic heart failure and determined if this association was modified by gender. This historical cohort study included 637 patients who were admitted to the Department of Cardiology, Herlev Hospital, Denmark, between 1 July 2005 and 30 June 2007. Baseline clinical data were obtained from patient records. Data on survival rates were obtained from the Danish Civil Registration System. Cox proportional hazard analysis was used to compute the hazard ratio (HR) of all-cause mortality, controlling for confounding factors. The median follow-up time was 2.8 years. A total of 323 (50.7%) patients died during the follow-up period. After adjustment for confounding factors, risk of death was associated with being single (HR = 1.53 (95% confidence interval: 1.19-1.96)). In a gender-stratified analysis, the risk of death did not differ among single-living women and men. Single living is a prognostic determinant of all-cause mortality in men and women with chronic heart failure. none. not relevant.

Neurodevelopmental Outcome and Health-related Quality of Life in Children With Single-ventricle Heart Disease Before Fontan Procedure.

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Reich, Bettina; Heye, Kristina; Tuura, Ruth; Beck, Ingrid; Wetterling, Kristina; Hahn, Andreas; Hofmann, Karoline; Schranz, Dietmar; Akintürk, Hakan; Latal, Beatrice; Knirsch, Walter

2017-12-05

Neurodevelopmental impairment and impaired quality of life constitute a major source of morbidity among children with complex congenital heart disease, in particular for single-ventricle (SV) morphologies. Risk factors and quality of life determining clinical and neurodevelopmental outcome at 2 years of age are examined. In a 2-center cohort study, 48 patients with SV morphology (26 hypoplastic left heart syndrome and 22 other types of univentricular heart defect) have been examined before Fontan procedure between 2010 and 2015. Patients were assessed with the Bayley Scales of Infant and Toddler Development, Third Version (Bayley-III), and the Preschool Children Quality of Life (TAPQOL) questionnaire. A total of 44 patients underwent hybrid procedure (n = 25), Norwood procedure (n = 7), or shunt or banding procedure (n = 12) as first surgery before subsequent bidirectional cavopulmonary anastomosis (n = 48). Median cognitive, language, and motor composite scores on the Bayley-III were 100 (range 65-120), 97 (68-124), and 97 (55-124), respectively. The language composite score was significantly below the norm (P = 0.025). Risk factors for poorer neurodevelopmental outcome were prolonged mechanical ventilation, longer days of hospital stay, and more reinterventions (all P neurodevelopmental outcome of this high-risk patient population. Copyright © 2017 Elsevier Inc. All rights reserved.

Role of LLD, a new locus for leaflet/pinna morphogenesis in Pisum ...

Indian Academy of Sciences (India)

Opposite pinnae of rachis nodes often formed fused incompletely developed leaflets. The lld mutation was observed to abort pinna development at almost all morphogenetic stages. The lld mutation demonstrated high penetrance and low expressivity. The phenotypes of lld plants in tl, tac, tl tac, tl af and tl af tac backgrounds ...

Single banking supervision and the single supervisory mechanism

Directory of Open Access Journals (Sweden)

Gheorghe, C. A.

2013-06-01

Full Text Available A resolution seems to have been found for the banking crisis. The first steps have been made towards the construction of the Economic and Monetary Union, steps involving the single supervision of banks, in order to avoid the discount of a new financial crisis on the expense of the EU state members. The Single Supervisory Mechanism – SSM is to become effective as of March 1, 2014, at the earliest.

Heart rate detection from single-foot plantar bioimpedance measurements in a weighing scale.

Science.gov (United States)

Diaz, Delia H; Casas, Oscar; Pallas-Areny, Ramon

2010-01-01

Electronic bathroom scales are an easy-to-use, affordable mean to measure physiological parameters in addition to body weight. They have been proposed to obtain the ballistocardiogram (BCG) and derive from it the heart rate, cardiac output and systolic blood pressure. Therefore, weighing scales may suit intermittent monitoring in e-health and patient screening. Scales intended for bioelectrical impedance analysis (BIA) have also been proposed to estimate the heart rate by amplifying the pulsatile impedance component superimposed on the basal impedance. However, electronic weighing scales cannot easily obtain the BCG from people that have a single leg neither are bioimpedance measurements between both feet recommended for people wearing a pacemaker or other electronic implants, neither for pregnant women. We propose a method to detect the heart rate (HR) from bioimpedance measured in a single foot while standing on an bathroom weighting scale intended for BIA. The electrodes built in the weighing scale are used to apply a 50 kHz voltage between the outer electrode pair and to measure the drop in voltage across the inner electrode pair. The agreement with the HR simultaneously obtained from the ECG is excellent. We have also compared the drop in voltage across the waist and the thorax with that obtained when measuring bioimpedance between both feet to compare the possible risk of the proposed method to that of existing BIA scales.

Heart Failure With Preserved Ejection Fraction in Diabetes: Mechanisms and Management.

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Meagher, Patrick; Adam, Mohamed; Civitarese, Robert; Bugyei-Twum, Antoinette; Connelly, Kim A

2018-05-01

Diabetes mellitus (DM) is a major cause of heart failure in the Western world, either secondary to coronary artery disease or from a distinct entity known as "diabetic cardiomyopathy." Furthermore, heart failure with preserved ejection fraction (HFpEF) is emerging as a significant clinical problem for patients with DM. Current clinical data suggest that between 30% and 40% of patients with HFpEF suffer from DM. The typical structural phenotype of the HFpEF heart consists of endothelial dysfunction, increased interstitial and perivascular fibrosis, cardiomyocyte stiffness, and hypertrophy along with advanced glycation end products deposition. There is a myriad of mechanisms that result in the phenotypical HFpEF heart including impaired cardiac metabolism and substrate utilization, altered insulin signalling leading to protein kinase C activation, advanced glycated end products deposition, prosclerotic cytokine activation (eg, transforming growth factor-β activation), along with impaired nitric oxide production from the endothelium. Moreover, recent investigations have focused on the role of endothelial-myocyte interactions. Despite intense research, current therapeutic strategies have had little effect on improving morbidity and mortality in patients with DM and HFpEF. Possible explanations for this include a limited understanding of the role that direct cell-cell communication or indirect cell-cell paracrine signalling plays in the pathogenesis of DM and HFpEF. Additionally, integrins remain another important mediator of signals from the extracellular matrix to cells within the failing heart and might play a significant role in cell-cell cross-talk. In this review we discuss the characteristics and mechanisms of DM and HFpEF to stimulate potential future research for patients with this common, and morbid condition. Copyright © 2018 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

Congenital heart defects: the 10-year experience at a single center.

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Aydin, Emine; Aypar, Ebru; Oktem, Ahmet; Ozyuncu, Ozgur; Yurdakok, Murat; Guvener, Murat; Demircin, Metin; Beksac, M Sinan

2018-06-18

We aimed to evaluate congenital heart disease (CHD) cases according to EUROCAT subgroup classification that were diagnosed during the prenatal period in our center. CHDs that were prenatally diagnosed using ultrasonography and confirmed by fetal echocardiography were reviewed over a 10-year period. Subgroup classification was finalized at the post-partum period in terms of the EUROCAT guide 1.3. Congenital heart defect subtypes and obstetric outcomes (gestational week at delivery, birth weight, gender, extracardiac structural abnormalities, karyotype results if performed) were analyzed. The data of 180 cases with CHD was examined. Left ventricular outflow tract obstruction (LVOT) was the most common CHD subtype (57/180; 31.6%), which included 48, five, and four cases of hypoplastic left heart syndrome (HLHS), coarctation of the aorta, and aortic valve atresia/stenosis, respectively. Eighteen pregnancies were terminated; the most common CHD subtype among patients of terminated pregnancies was hypoplastic left heart syndrome (HLHS) (n = 7, 38.8%). The most common extracardiac malformations were a single umbilical artery, esophageal atresia, and situs inversus in our study group. Eighteen of the 96 (18.75%) neonates with CHD died during the neonatal period. The most common CHD subtype was HLHS (7/18; 38%) among the newborns who died after birth. Prenatal diagnosis of a CHD and subgroup classification is very important for clinical decision making, including prenatal management, recommendations for termination of the pregnancy, postnatal management of the patient, and for early referral to pediatric cardiology and cardiovascular surgery centers.

Single-Parent and Working-Parent Heart Health

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... Check Recipe Certification Program Nutrition Requirements Heart-Check Professional Resources Contact the Heart-Check Certification Program Simple Cooking and Recipes Dining Out Choosing a Restaurant Deciphering ...

Dynamic 123I-BMIPP single-photon emission computed tomography in patients with congestive heart failure: effect of angiotensin II type-1 receptor blockade.

Science.gov (United States)

Takeishi, Yasuchika; Minamihaba, Osamu; Yamauchi, Sou; Arimoto, Takanori; Hirono, Osamu; Takahashi, Hiroki; Akiyama, Hideyuki; Miyamoto, Takuya; Nitobe, Joji; Nozaki, Naoki; Tachibana, Hidetada; Okuyama, Masaki; Fukui, Akio; Kubota, Isao; Okada, Akio; Takahashi, Kazuei

2004-04-01

Heart failure is a major and growing public health problem with a high mortality rate. Although recent studies have demonstrated that a variety of metabolic and/or neurohumoral factors are involved in the progression of this syndrome, the precise mechanisms responsible for this complex condition are poorly understood. To examine 123I-beta-methyl-iodophenylpentadecanoic acid (BMIPP) kinetics in the early phase soon after tracer injection in patients with congestive heart failure (CHF), we performed dynamic single-photon emission computed tomography (SPECT). Twenty-six patients with CHF and eight control subjects were examined. The consecutive 15 images of 2-min dynamic SPECT were acquired for 30 min after injection. In the early phase after injection (0-4 min), a significant amount of radioactivity existed in the blood pool. After 6 min, the myocardial 123I-BMIPP image was clear and thus the washout rate of 123I-BMIPP from 6 to 30 min was calculated. The washout rate of 123I-BMIPP from the myocardium was faster in patients with CHF than in the controls (8 +/- 4 vs. -5 +/- 3%, p acid metabolism may represent a new mechanism for beneficial effects of angiotensin II receptor blockade on cardiac function and survival in patients with heart failure. 123I-BMIPP washout in the early phase obtained from dynamic SPECT may be a new marker for evaluating the severity of heart failure and the effects of medical treatment.

[Mechanism of "treating heart and brain with same methods" based on data science].

Science.gov (United States)

Chen, Di; Tang, Shi-huan; Lu, Peng; Yang, Hong-jun

2015-11-01

The traditional Chinese medicine (TCM) theory of "treating heart and brain diseases with same methods (Nao Xin Tong Zhi: NXTZ)" has great significance to the treatment of cardiovascular and cerebrovascular diseases. It has been proven effective by a great deal of clinical researches. However, the underlying mechanism for this theory is still unclear. To provide insights into the potential mechanism of "NXTZ", this study attempts to deeply investigate the mechanism from two representative cardiovascular and cerebrovascular diseases, coronary heart disease (CHD) and cerebral apoplexy. First, various data resources were integrated to obtain different types of biomedical entities including drugs, targets, pathways and diseases. Then, three different approaches including text mining, biological network and enrichment analysis were utilized to recognize the potential common features between CHD and cerebral apoplexy, and the corresponding functions of drugs which could treat both diseases, thus unveiling the mechanism of NXTZ.

Recommendations for the anticoagulation of pregnant patients with mechanical heart valves

NARCIS (Netherlands)

Schapkaitz, Elise; Jacobson, Barry Frank; Manga, Pravin; Chitsike, Rufaro Saeed; Benade, Estee; Haas, Sylvia; Buller, Harry R.

2015-01-01

The management of pregnant patients with mechanical heart valves remains challenging because there are no large randomised studies to provide guidelines for effective anticoagulant therapy. Both vitamin K antagonists and heparins may be associated with maternal and foetal adverse events. The

Preparation, validation and user-testing of pictogram-based patient information leaflets for tuberculosis.

Science.gov (United States)

Shrestha, Anmol; Rajesh, V; Dessai, Sneha Shamrao; Stanly, Sharon Mary; Mateti, Uday Venkat

2018-05-25

Patient education is of paramount importance with regard to the condition of the disease and the treatment given besides lifestyle remodelling in order to get the desired therapeutic outcome. When verbal information is provided to the patients, they often tend to forget it. Pictorial aids or pictograms, as they are commonly known, are tools that are widely used for imparting knowledge to the patients. The aim of the study is to prepare and validate a Pictogram-based Patient Information Leaflet (P-PILs) on Tuberculosis (TB). P-PILs have been prepared from tertiary, secondary and primary sources. The knowledge-based questions are prepared with respect to the P-PILs. The baseline knowledge of the volunteers and patients have been analyzed before administering the P-PILs by using the validated questionnaire. The post-knowledge of the volunteers and patients has been analyzed after administering the P-PILs (20 min) by using the same questionnaire and the user-opinion has also been obtained at the end. The study results show that the mean scores of the overall user-testing knowledge assessment are found to have improved significantly from the pre-P-PILs administration score of 62.67 to the post-P-PILs administration score of 91. The overall user-opinion about the P-PILs has been found to be good (75%) followed by average (25%). The present study shows that there is significant improvement in the knowledge levels of the patients and volunteers after reading the validated leaflets. The Pictogram-based Patient Information Leaflets are found to be an effective educational tool for TB patients. Copyright © 2018. Published by Elsevier Ltd.

Glutamate transporter type 3 knockout leads to decreased heart rate possibly via parasympathetic mechanism

OpenAIRE

Deng, Jiao; Li, Jiejie; Li, Liaoliao; Feng, Chenzhuo; Xiong, Lize; Zuo, Zhiyi

2013-01-01

Parasympathetic tone is a dominant neural regulator for basal heart rate. Glutamate transporters (EAAT) via their glutamate uptake functions regulate glutamate neurotransmission in the central nervous system. We showed that EAAT type 3 (EAAT3) knockout mice had a slower heart rate than wild-type mice when they were anesthetized. We design this study to determine whether non-anesthetized EAAT3 knockout mice have a slower heart rate and, if so, what may be the mechanism for this effect. Young a...

Cardioscopic tricuspid valve repair in a beating ovine heart.

Science.gov (United States)

Umakanthan, Ramanan; Ghanta, Ravi K; Rangaraj, Aravind T; Lee, Lawrence S; Laurence, Rita G; Fox, John A; Mihaljevic, Tomislav; Bolman, Ralph M; Cohn, Lawrence H; Chen, Frederick Y

2009-04-01

Open heart surgery is commonly associated with cardiopulmonary bypass and cardioplegic arrest. The attendant risks of cardiopulmonary bypass may be prohibitive in high-risk patients. We present a novel endoscopic technique of performing tricuspid valve repair without cardiopulmonary bypass in a beating ovine heart. Six sheep underwent sternotomy and creation of a right heart shunt to eliminate right atrial and right ventricular blood for clear visualization. The superior vena cava, inferior vena cava, pulmonary artery, and coronary sinus were cannulated, and the blood flow from these vessels was shunted into the pulmonary artery via a roller pump. The posterior leaflet of the tricuspid valve was partially excised to create tricuspid regurgitation, which was confirmed by Doppler echocardiography. A 7.0-mm fiberoptic videoscope was inserted into the right atrium to visualize the tricuspid valve. Under cardioscopic vision, an endoscopic needle driver was inserted into the right atrium, and a concentric stitch was placed along the posterior annulus to bicuspidize the tricuspid valve. Doppler echocardiography confirmed reduction of tricuspid regurgitation. All animals successfully underwent and tolerated the surgical procedure. The right heart shunt generated a bloodless field, facilitating cardioscopic tricuspid valve visualization. The endoscopic stitch resulted in annular plication and functional tricuspid valve bicuspidization, significantly reducing the degree of tricuspid regurgitation. Cardioscopy enables less invasive, beating-heart tricuspid valve surgery in an ovine model. This technique may be useful in performing right heart surgery without cardiopulmonary bypass in high-risk patients.

[EFFECT OF EDUCATIONAL LEAFLETS ON KNOWLEDGE AND ATTITUDE TO TUBERCULOSIS AMONG HOMELESS PERSONS IN TOKYO, JAPAN].

Science.gov (United States)

Kawatsu, Lisa; Uchimura, Kazuhiro; Watabe, Hiroyuki; Kaguraoka, Sumi; Kubota, Yuka; Sakakibara, Marie; Ishikawa, Nobukatsu

2015-08-01

Delay in seeking care is one of the critical issues in tuberculosis (TB) control among homeless persons in Japan. Yet knowledge of and attitude towards TB among homeless persons have remained unclear and limited efforts have been made to disseminate information related to TB among homeless persons. To evaluate the effect of TB leaflets, produced and distributed to homeless persons by a group of ex-homeless TB patients, and to understand what homeless persons know about TB. Self-administered questionnaire was conducted among homeless persons before and after distribution of the TB leaflets. Changes in the responses to each question were also subjected to principal component analysis to group questions into types according to response patterns and identify constructs of TB-related knowledge. Results of 88 participants were analyzed. TB knowledge score related to risks and symptoms significantly improved after the intervention (from 54.3% to 70.6%, p < 0.05), while knowledge on treatment cost did not. Two components were identified, namely, the "improvement in TB impression" and "improvement in TB knowledge". TB leaflets were effective in improving certain aspects of TB knowledge. However, its effect on knowledge regarding treatment cost, which may be crucial in improving delay, was limited and thus the messages need to be revised.

Continuum mechanics of single-substance bodies

CERN Document Server

Eringen, A Cemal

1975-01-01

Continuum Physics, Volume II: Continuum Mechanics of Single-Substance Bodies discusses the continuum mechanics of bodies constituted by a single substance, providing a thorough and precise presentation of exact theories that have evolved during the past years. This book consists of three parts-basic principles, constitutive equations for simple materials, and methods of solution. Part I of this publication is devoted to a discussion of basic principles irrespective of material geometry and constitution that are valid for all kinds of substances, including composites. The geometrical notions, k

Pannus-Related Mechanical Valve Dysfunction Leading to Hemodynamic Shock

Directory of Open Access Journals (Sweden)

Manabu Shiraishi

2012-02-01

Full Text Available Mechanical prosthetic valve dysfunction caused by pannus formation is rare. Pannus restricts movement of prosthetic valve leaflets, resulting in severe aortic regurgitation. We describe the case of a 77-year-old woman who presented to the emergency room with increasing dyspnea, ischemia, and shock secondary to mechanical aortic valve dysfunction. Transesophageal echocardiography showed a blockade of the leaflets of the mechanical aortic valve, with severe aortic regurgitation. She underwent emergent cardiac surgery for aortic valve replacement. Pannus formation should be considered as a potential cause of acute severe aortic regurgitation in a patient with a small-sized mechanical aortic prosthesis in the supra-annular position. On a pathological exam, extensive pannus was found on the ventricular side of the prosthetic valve, extending from the ring into the central orifice. [Arch Clin Exp Surg 2012; 1(1.000: 50-53

High prevalence of rheumatic heart disease detected by echocardiography in school children.

Science.gov (United States)

Bhaya, Maneesha; Panwar, Sadik; Beniwal, Rajesh; Panwar, Raja Babu

2010-04-01

It is fairly easy to detect advanced valve lesions of established rheumatic heart disease by echocardiography in the clinically identified cases of rheumatic heart disease. However, to diagnose a subclinical case of rheumatic heart disease, no uniform set of echocardiographic criteria exist. Moderate thickening of valve leaflets is considered an indicator of established rheumatic heart disease. World Health Organization criteria for diagnosing probable rheumatic heart disease are more sensitive and are based on the detection of significant regurgitation of mitral and/or aortic valves by color Doppler. We attempted diagnosing RHD in school children in Bikaner city by cardiac ultrasound. The stratified cluster sampling technique was employed to identify 31 random clusters in the coeducational schools of Bikaner city. We selected 1059 school children aged 6-15 years from these schools. An experienced operator did careful cardiac auscultation and echocardiographic study. A second expert confirmed the echocardiographic findings. The prevalence of lesions suggestive of rheumatic heart disease by echocardiography was 51 per 1,000 (denominator = 1059; 95% CI: 38-64 per 1,000). We were able to clinically diagnose RHD in one child. None of these children or their parents having echocardiographic evidence of RHD could provide a positive history of acute rheumatic fever. By echocardiographic screening, we found a high prevalence of rheumatic heart disease in the surveyed population. Clinical auscultation had much lower diagnostic efficacy.

Energy consumption of small refrigerators - Information leaflet; Merkblatt Kleinkuehlschrank

Energy Technology Data Exchange (ETDEWEB)

NONE

2009-07-01

In this leaflet published by the Swiss Federal Office of Energy (SFOE), the energy consumption of small refrigerators with a capacity of less than 100 litres is reported on. Such small refrigerators are often used in hotel rooms or in campers. It is noted that, in comparison, a typical, 150 litre class A++ domestic refrigerator uses only a fraction of the amount of energy used by such small refrigerators. The results of measurements made according to EN 153 and ISO 15502 norms are discussed. Recommendations are made on the purchase and operation of these small refrigerators.

Tetralogy of Fallot with restrictive ventricular septal defect by accessory tricuspid leaflet tissue

OpenAIRE

Mahipat Raj Soni; Deepak A. Bohara; Ajay U. Mahajan; Pratap J. Nathani

2012-01-01

In tetralogy of Fallot septal defect is usually large because of malalignment of outlet septum, restrictive defect has been reported rarely. We present a case of tetralogy of Fallot with accessory tricuspid leaflet tissue restricting ventricular septal defect. The report includes echocardiographic and catheter images of this rare presentation of tetralogy of Fallot.

Mitochondrial damage: An important mechanism of ambient PM2.5 exposure-induced acute heart injury in rats

International Nuclear Information System (INIS)

Li, Ruijin; Kou, Xiaojing; Geng, Hong; Xie, Jingfang; Tian, Jingjing; Cai, Zongwei; Dong, Chuan

2015-01-01

Highlights: • PM 2.5 induces heart mitochondrial morphological damage of rats. • Mitochondrial fission/fusion gene expression is important regulation mechanism. • Proinflammatoy cytokine level changes are accompanied with mitochondrial damage. • Alterations in oxidative stress and calcium homeostasis are focused on. - Abstract: Epidemiological studies suggested that ambient fine particulate matter (PM 2.5 ) exposure was associated with cardiovascular disease. However, the underlying mechanism, especially the mitochondrial damage mechanism, of PM 2.5 -induced heart acute injury is still unclear. In this study, the alterations of mitochondrial morphology and mitochondrial fission/fusion gene expression, oxidative stress, calcium homeostasis and inflammation in hearts of rats exposed to PM 2.5 with different dosages (0.375, 1.5, 6.0 and 24.0 mg/kg body weight) were investigated. The results indicated that the PM 2.5 exposure induced pathological changes and ultra-structural damage in hearts such as mitochondrial swell and cristae disorder. Furthermore, PM 2.5 exposure significantly increased specific mitochondrial fission/fusion gene (Fis1, Mfn1, Mfn2, Drp1 and OPA1) expression in rat hearts. These changes were accompanied by decreases of activities of superoxide dismutase (SOD), Na + K + -ATPase and Ca 2+ -ATPase and increases of levels of malondialdehyde (MDA), inducible nitric oxide synthase (iNOS) and nitric oxide (NO) as well as levels of pro-inflammatory mediators including TNF-α, IL-6 and IL-1β in rat hearts. The results implicate that mitochondrial damage, oxidative stress, cellular homeostasis imbalance and inflammation are potentially important mechanisms for the PM 2.5 -induced heart injury, and may have relations with cardiovascular disease

Introduction to forest diseases -- revised edition. Pest leaflet No. FPL 54

Energy Technology Data Exchange (ETDEWEB)

Callan, B.E.

1994-12-31

This leaflet provides a basic introduction to forest pathology. It includes descriptions of the common types of forest diseases and their causes as well as an outline of modern principles of disease control and investigation. It describes fungus classes associated with tree diseases, fungus anatomy, and examples of diseases caused by fungi; viruses, bacteria, and mycoplasma-like organisms; diseases caused by dwarf mistletoe; and non-infectious agents of disease. A glossary is included.

Imaging of pannus formation in patients with mechanical heart valves.

Science.gov (United States)

Gündüz, Sabahattin; Özkan, Mehmet; Yesin, Mahmut

2015-11-26

Patient-prosthesis mismatch (PPM) should be recognized in patients with elevated transprosthetic gradients but without leaflet immobility, since the treatment strategy may differ in either etiology. However, thrombus and/or pannus formation should be excluded before a diagnosis of PPM is made. Particularly, pannus formation may not be diagnosed with 2-dimensional transesophageal echocardiography. Electrocardiographically gated 64-section multidetector computed tomography (MDCT) may be a promising tool in diagnosing or excluding pannus formation. Our report underlines the utility of MDCT in this regard and also emphasizes the importance of recognition of PPM as a differential diagnosis in such patients.

Mechanism of the superior mechanical strength of nanometer-sized metal single crystals revealed

KAUST Repository

Afify, N. D.

2013-10-01

Clear understanding of the superior mechanical strength of nanometer-sized metal single crystals is required to derive advanced mechanical components retaining such superiority. Although high quality studies have been reported on nano-crystalline metals, the superiority of small single crystals has neither been fundamentally explained nor quantified to this date. Here we present a molecular dynamics study of aluminum single crystals in the size range from 4.1 nm to 40.5 nm. We show that the ultimate mechanical strength deteriorates exponentially as the single crystal size increases. The small crystals superiority is explained by their ability to continuously form vacancies and to recover them. © 2013 Published by Elsevier B.V.

Introduction of a paediatric anaesthesia comic information leaflet reduced preoperative anxiety in children.

Science.gov (United States)

Kassai, B; Rabilloud, M; Dantony, E; Grousson, S; Revol, O; Malik, S; Ginhoux, T; Touil, N; Chassard, D; Pereira de Souza Neto, E

2016-07-01

The aim of the study was to determine whether the introduction of a paediatric anaesthesia comic information leaflet reduced preoperative anxiety levels of children undergoing major surgery. Secondary objectives were to determine whether the level of understanding of participants and other risk factors influence STAIC-S (State-Trait Anxiety Inventory for Children-State subscale) score in children. We performed a randomized controlled parallel-group trial comparing preoperative anxiety between two groups of children aged >6 and comic information leaflet at home in addition to routine information given by the anaesthetist at least 1 day before surgery. The control group received the routine information only. The outcome measure was the difference between STAIC-S scores measured before any intervention and after the anaesthetist's visit. A multiple regression analysis was performed to explore the influence of the level of education, the anxiety of parents, and the childrens' intelligence quotient on STAIC-S scores. One hundred and fifteen children were randomized between April 2009 and April 2013. An intention-to-treat analysis on data from 111 patients showed a significant reduction (P=0.002) in STAIC-S in the intervention group (n=54, mean=-2.2) compared with the control group (n=57, mean=0.90). The multiple regression analysis did not show any influence on STAIC-S scores of the level of education, parental anxiety, or the intelligence quotient of the children. A paediatric anaesthesia comic information leaflet was a cheap and effective means of reducing preoperative anxiety, measured by STAIC-S, in children. NCT 00841022. © The Author 2016. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Tissue engineering of heart valves: in vitro experiences.

Science.gov (United States)

Sodian, R; Hoerstrup, S P; Sperling, J S; Daebritz, S H; Martin, D P; Schoen, F J; Vacanti, J P; Mayer, J E

2000-07-01

Tissue engineering is a new approach, whereby techniques are being developed to transplant autologous cells onto biodegradable scaffolds to ultimately form new functional tissue in vitro and in vivo. Our laboratory has focused on the tissue engineering of heart valves, and we have fabricated a trileaflet heart valve scaffold from a biodegradable polymer, a polyhydroxyalkanoate. In this experiment we evaluated the suitability of this scaffold material as well as in vitro conditioning to create viable tissue for tissue engineering of a trileaflet heart valve. We constructed a biodegradable and biocompatible trileaflet heart valve scaffold from a porous polyhydroxyalkanoate (Meatabolix Inc, Cambridge, MA). The scaffold consisted of a cylindrical stent (1 x 15 x 20 mm inner diameter) and leaflets (0.3 mm thick), which were attached to the stent by thermal processing techniques. The porous heart valve scaffold (pore size 100 to 240 microm) was seeded with vascular cells grown and expanded from an ovine carotid artery and placed into a pulsatile flow bioreactor for 1, 4, and 8 days. Analysis of the engineered tissue included biochemical examination, enviromental scanning electron microscopy, and histology. It was possible to create a trileaflet heart valve scaffold from polyhydroxyalkanoate, which opened and closed synchronously in a pulsatile flow bioreactor. The cells grew into the pores and formed a confluent layer after incubation and pulsatile flow exposure. The cells were mostly viable and formed connective tissue between the inside and the outside of the porous heart valve scaffold. Additionally, we demonstrated cell proliferation (DNA assay) and the capacity to generate collagen as measured by hydroxyproline assay and movat-stained glycosaminoglycans under in vitro pulsatile flow conditions. Polyhydroxyalkanoates can be used to fabricate a porous, biodegradable heart valve scaffold. The cells appear to be viable and extracellular matrix formation was induced

Validation of a numerical FSI simulation of an aortic BMHV by in vitro PIV experiments.

Science.gov (United States)

Annerel, S; Claessens, T; Degroote, J; Segers, P; Vierendeels, J

2014-08-01

In this paper, a validation of a recently developed fluid-structure interaction (FSI) coupling algorithm to simulate numerically the dynamics of an aortic bileaflet mechanical heart valve (BMHV) is performed. This validation is done by comparing the numerical simulation results with in vitro experiments. For the in vitro experiments, the leaflet kinematics and flow fields are obtained via the particle image velocimetry (PIV) technique. Subsequently, the same case is numerically simulated by the coupling algorithm and the resulting leaflet kinematics and flow fields are obtained. Finally, the results are compared, revealing great similarity in leaflet motion and flow fields between the numerical simulation and the experimental test. Therefore, it is concluded that the developed algorithm is able to capture very accurately all the major leaflet kinematics and dynamics and can be used to study and optimize the design of BMHVs. Copyright © 2014 IPEM. Published by Elsevier Ltd. All rights reserved.

Increased expression of the auxiliary beta(2-subunit of ventricular L-type Ca(2+ channels leads to single-channel activity characteristic of heart failure.

Directory of Open Access Journals (Sweden)

Roger Hullin

2007-03-01

Full Text Available Increased activity of single ventricular L-type Ca(2+-channels (L-VDCC is a hallmark in human heart failure. Recent findings suggest differential modulation by several auxiliary beta-subunits as a possible explanation.By molecular and functional analyses of human and murine ventricles, we find that enhanced L-VDCC activity is accompanied by altered expression pattern of auxiliary L-VDCC beta-subunit gene products. In HEK293-cells we show differential modulation of single L-VDCC activity by coexpression of several human cardiac beta-subunits: Unlike beta(1 or beta(3 isoforms, beta(2a and beta(2b induce a high-activity channel behavior typical of failing myocytes. In accordance, beta(2-subunit mRNA and protein are up-regulated in failing human myocardium. In a model of heart failure we find that mice overexpressing the human cardiac Ca(V1.2 also reveal increased single-channel activity and sarcolemmal beta(2 expression when entering into the maladaptive stage of heart failure. Interestingly, these animals, when still young and non-failing ("Adaptive Phase", reveal the opposite phenotype, viz: reduced single-channel activity accompanied by lowered beta(2 expression. Additional evidence for the cause-effect relationship between beta(2-subunit expression and single L-VDCC activity is provided by newly engineered, double-transgenic mice bearing both constitutive Ca(V1.2 and inducible beta(2 cardiac overexpression. Here in non-failing hearts induction of beta(2-subunit overexpression mimicked the increase of single L-VDCC activity observed in murine and human chronic heart failure.Our study presents evidence of the pathobiochemical relevance of beta(2-subunits for the electrophysiological phenotype of cardiac L-VDCC and thus provides an explanation for the single L-VDCC gating observed in human and murine heart failure.

Mitochondrial damage: An important mechanism of ambient PM{sub 2.5} exposure-induced acute heart injury in rats

Energy Technology Data Exchange (ETDEWEB)

Li, Ruijin; Kou, Xiaojing; Geng, Hong; Xie, Jingfang; Tian, Jingjing [Institute of Environmental Science, College of Environmental & Resource Sciences, Shanxi University, Taiyuan (China); Cai, Zongwei, E-mail: zwcai@hkbu.edu.hk [State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Hong Kong SAR (China); Dong, Chuan, E-mail: dc@sxu.edu.cn [Institute of Environmental Science, College of Environmental & Resource Sciences, Shanxi University, Taiyuan (China)

2015-04-28

Highlights: • PM{sub 2.5} induces heart mitochondrial morphological damage of rats. • Mitochondrial fission/fusion gene expression is important regulation mechanism. • Proinflammatoy cytokine level changes are accompanied with mitochondrial damage. • Alterations in oxidative stress and calcium homeostasis are focused on. - Abstract: Epidemiological studies suggested that ambient fine particulate matter (PM{sub 2.5}) exposure was associated with cardiovascular disease. However, the underlying mechanism, especially the mitochondrial damage mechanism, of PM{sub 2.5}-induced heart acute injury is still unclear. In this study, the alterations of mitochondrial morphology and mitochondrial fission/fusion gene expression, oxidative stress, calcium homeostasis and inflammation in hearts of rats exposed to PM{sub 2.5} with different dosages (0.375, 1.5, 6.0 and 24.0 mg/kg body weight) were investigated. The results indicated that the PM{sub 2.5} exposure induced pathological changes and ultra-structural damage in hearts such as mitochondrial swell and cristae disorder. Furthermore, PM{sub 2.5} exposure significantly increased specific mitochondrial fission/fusion gene (Fis1, Mfn1, Mfn2, Drp1 and OPA1) expression in rat hearts. These changes were accompanied by decreases of activities of superoxide dismutase (SOD), Na{sup +}K{sup +}-ATPase and Ca{sup 2+}-ATPase and increases of levels of malondialdehyde (MDA), inducible nitric oxide synthase (iNOS) and nitric oxide (NO) as well as levels of pro-inflammatory mediators including TNF-α, IL-6 and IL-1β in rat hearts. The results implicate that mitochondrial damage, oxidative stress, cellular homeostasis imbalance and inflammation are potentially important mechanisms for the PM{sub 2.5}-induced heart injury, and may have relations with cardiovascular disease.

Estimation of mechanical properties of single wall carbon nanotubes ...

Indian Academy of Sciences (India)

Molecular mechanics; single wall carbon nanotube; mechanical proper- ... Fracture Mechanics); Rossi & Meo 2009). Furthermore, the work carried out by Natsuki & Endo. (2004), Xiao et al (2005) and Sun & Zhao (2005) in the direction of ..... Jin Y and Yuan F G 2003 Simulation of elastic properties of single walled carbon ...

Functional requirements of a mathematical model of the heart.

Science.gov (United States)

Palladino, Joseph L; Noordergraaf, Abraham

2009-01-01

Functional descriptions of the heart, especially the left ventricle, are often based on the measured variables pressure and ventricular outflow, embodied as a time-varying elastance. The fundamental difficulty of describing the mechanical properties of the heart with a time-varying elastance function that is set a priori is described. As an alternative, a new functional model of the heart is presented, which characterizes the ventricle's contractile state with parameters, rather than variables. Each chamber is treated as a pressure generator that is time and volume dependent. The heart's complex dynamics develop from a single equation based on the formation and relaxation of crossbridge bonds. This equation permits the calculation of ventricular elastance via E(v) = partial differentialp(v)/ partial differentialV(v). This heart model is defined independently from load properties, and ventricular elastance is dynamic and reflects changing numbers of crossbridge bonds. In this paper, the functionality of this new heart model is presented via computed work loops that demonstrate the Frank-Starling mechanism and the effects of preload, the effects of afterload, inotropic changes, and varied heart rate, as well as the interdependence of these effects. Results suggest the origin of the equivalent of Hill's force-velocity relation in the ventricle.

Nondestructive and noninvasive assessment of mechanical properties in heart valve tissue engineering

NARCIS (Netherlands)

Kortsmit, J.; Driessen, N.J.B.; Rutten, M.C.M.; Baaijens, F.P.T.

2009-01-01

Despite recent progress, mechanical behavior of tissue-engineered heart valves still needs improvement when native aortic valves are considered as a benchmark. Although it is known that cyclic straining enhances tissue formation, optimal loading protocols have not been defined yet. To obtain a

Lay-friendliness in translated Patient Information Leaflets

DEFF Research Database (Denmark)

Jensen, Matilde Nisbeth; Zethsen, Karen Korning

This paper seeks to empirically explore the claim that translated Danish Patient Information Leaflets (PILs) are less lay-friendly than their English source texts. The last two decades have seen an increased focus on providing patients with lay-friendly, easily understood information, enabling them...... to make informed decisions concerning their health. For this purpose, many new genres have been created, one such genre being the PIL, a mandatory text which in an EU context has to accompany all medication informing patients about dosage, side effects etc. Legally, the PIL genre is required to ensure lay......-friendly information as it must be “written and designed to be clear and understandable, enabling the users to act appropriately” (Article 63(2) of EU Directive 2001/83/EC). Despite the legal requirements and the intensified focus on lay-friendly health communication, many studies have shown that PILs are often...

Interdigitation of long-chain sphingomyelin induces coupling of membrane leaflets in a cholesterol dependent manner

DEFF Research Database (Denmark)

Róg, Tomasz; Orłowski, Adam; Llorente, Alicia

2016-01-01

It has been a long-standing question how the two leaflets in a lipid bilayer modulate each others' physical properties. In this paper, we discuss how this interaction may take place through interdigitation. We use atomistic molecular dynamics simulations to consider asymmetric lipid membrane mode...

Treatment of severe mitral regurgitation caused by lesions in both leaflets using multiple mitral valve plasty techniques in a small dog

Directory of Open Access Journals (Sweden)

Satoko Yokoyama

2017-11-01

Full Text Available Mitral valve plasty (MVP is preferred over mitral valve replacement (MVR for mitral regurgitation in humans because of its favorable effect on quality of life. In small dogs, it is difficult to repair multiple lesions in both leaflets using MVP. Herein, we report a case of severe mitral regurgitation caused by multiple severe lesions in the posterior leaflet (PL in a mixed Chihuahua. Initially, we had planned MVR with an artificial valve. However, MVP combined with artificial chordal reconstruction of both leaflets, semicircular suture annuloplasty, and valvuloplasty using a newly devised direct scallop suture for the PL was attempted in this dog. The dog recovered well and showed no adverse cardiac signs, surviving two major operations. The dog died 4 years and 10 months after the MVP due to non-cardiovascular disease. Our additional technique of using a direct scallop suture seemed useful for PL repair involving multiple scallops in a small dog.

Relief of mitral leaflet tethering following chronic myocardial infarction by chordal cutting diminishes left ventricular remodeling.

Science.gov (United States)

Messas, Emmanuel; Bel, Alain; Szymanski, Catherine; Cohen, Iris; Touchot, Bernard; Handschumacher, Mark D; Desnos, Michel; Carpentier, Alain; Menasché, Philippe; Hagège, Albert A; Levine, Robert A

2010-11-01

one of the key targets in treating mitral regurgitation (MR) is reducing the otherwise progressive left ventricular (LV) remodeling that exacerbates MR and conveys adverse prognosis. We have previously demonstrated that severing 2 second-order chordae to the anterior mitral leaflet relieves tethering and ischemic MR acutely. The purpose of this study was to test whether this technique reduces the progression of LV remodeling in the chronic ischemic MR setting. a posterolateral MI was created in 18 sheep by obtuse marginal branch ligation. After chronic remodeling and MR development at 3 months, 6 sheep were randomized to sham surgery (control group) and 12 to second-order chordal cutting (6 each to anterior leaflet [AntL] and bileaflet [BiL] chordal cutting, techniques that are in clinical application). At baseline, chronic infarction (3 months), and follow-up at a mean of 6.6 months post-myocardial infarction (MI) (euthanasia), we measured LV end-diastolic (EDV) and end-systolic volume (ESV), ejection fraction, wall motion score index, and posterior leaflet (PL) restriction angle relative to the annulus by 2D and 3D echocardiography. All measurements were comparable among groups at baseline and chronic MI. At euthanasia, AntL and BiL chordal cutting limited the progressive remodeling seen in controls. LVESV increased relative to chronic MI by 109±8.7% in controls versus 30.5±6.1% with chordal cutting (Pbenefits have the potential to improve clinical outcomes.

Mechanism of action of ethanol on heart contractility

International Nuclear Information System (INIS)

Oquendo-Muriente, I.; De Mello, W.C.

1986-01-01

Ethanol depresses heart contractility. To investigate the mechanism of the negative inotropic action of ethanol, rat ventricular strips were dissected and mounted vertically in a transparent chamber. The preparation was superfused initially with normal oxygenated Tyrode solution (32.5 0 C) and electrically stimulated (1 Hz). After 1 hour of equilibration, contractures were elicited by exposing the muscle strips to high K + (100 mM) solution. Studies on the influence of (Ca 2+ ) 0 on K + contractures showed that the first rapid component of the contracture (58 mg/sec - S.E. +/- 8; n = 8) was greatly dependent upon (Ca 2+ ) 0 while the second slow component (20 mg/sec - S.E. +/- 5; n = 8) was slightly altered. The addition of ethanol (400 mg/100 ml) to high K solution abolished the fast component and reduced the amplitude of the second phase of K contractures. Similar results were obtained with verapamil (10 -5 M). These results, as well as studies on the effect of the drug on 45 Ca fluxes support the view that ethanol decreases the permeability of the heart cell membrane to Ca

Mechanism of action of ethanol on heart contractility

Energy Technology Data Exchange (ETDEWEB)

Oquendo-Muriente, I.; De Mello, W.C.

1986-03-05

Ethanol depresses heart contractility. To investigate the mechanism of the negative inotropic action of ethanol, rat ventricular strips were dissected and mounted vertically in a transparent chamber. The preparation was superfused initially with normal oxygenated Tyrode solution (32.5/sup 0/C) and electrically stimulated (1 Hz). After 1 hour of equilibration, contractures were elicited by exposing the muscle strips to high K/sup +/ (100 mM) solution. Studies on the influence of (Ca/sup 2 +/)/sub 0/ on K/sup +/ contractures showed that the first rapid component of the contracture (58 mg/sec - S.E. +/- 8; n = 8) was greatly dependent upon (Ca/sup 2 +/)/sub 0/ while the second slow component (20 mg/sec - S.E. +/- 5; n = 8) was slightly altered. The addition of ethanol (400 mg/100 ml) to high K solution abolished the fast component and reduced the amplitude of the second phase of K contractures. Similar results were obtained with verapamil (10/sup -5/ M). These results, as well as studies on the effect of the drug on /sup 45/Ca fluxes support the view that ethanol decreases the permeability of the heart cell membrane to Ca.

Radiation-induced changes in the ultrastructure and mechanical function of the rat heart

International Nuclear Information System (INIS)

Cilliers, G.D.; Lochner, A.

1989-01-01

A time sequence study was performed to study the early effects of radiation on the ultrastructure of the rat heart. Wistar rats were exposed to 20 Gy electron irradiation to a field including the heart and a third of the lung. The hearts were excised at varying time intervals (1 h-180 days), and the ultrastructure of perfusion-fixed subepicardium and subendocardium studied. Changes were observed in both myocytes and interstitium at all time intervals. The most pronounced change observed in the myocyte was that of intercalated disc damage which reached a peak at 30 days post-irradiation. Mitochondrial damage, characterized by swelling and fenstration in areas of myofibrillar contracture, was focal and relatively scarce. Swelling of the capillary endothelial cells and ollapse of the capillaries were marked up to 60 days. Of significance was the observation that the damage to both myocytes and interstitium receded after 60 days and the hearts exhibited an almost normal ultrastructure from 100 to 180 days post-irradiation. Mechanical function of these hearts followed a similar pattern: maximal depression was observed 60 days after irradiation. Thereafter the work performance of these hearts improved significantly, almost reaching control level after 180 days. (author). 34 refs.; 21 figs.; 1 tab

Interleaflet Coupling, Pinning, and Leaflet Asymmetry—Major Players in Plasma Membrane Nanodomain Formation

Science.gov (United States)

Fujimoto, Toyoshi; Parmryd, Ingela

2017-01-01

The plasma membrane has a highly asymmetric distribution of lipids and contains dynamic nanodomains many of which are liquid entities surrounded by a second, slightly different, liquid environment. Contributing to the dynamics is a continuous repartitioning of components between the two types of liquids and transient links between lipids and proteins, both to extracellular matrix and cytoplasmic components, that temporarily pin membrane constituents. This make plasma membrane nanodomains exceptionally challenging to study and much of what is known about membrane domains has been deduced from studies on model membranes at equilibrium. However, living cells are by definition not at equilibrium and lipids are distributed asymmetrically with inositol phospholipids, phosphatidylethanolamines and phosphatidylserines confined mostly to the inner leaflet and glyco- and sphingolipids to the outer leaflet. Moreover, each phospholipid group encompasses a wealth of species with different acyl chain combinations whose lateral distribution is heterogeneous. It is becoming increasingly clear that asymmetry and pinning play important roles in plasma membrane nanodomain formation and coupling between the two lipid monolayers. How asymmetry, pinning, and interdigitation contribute to the plasma membrane organization is only beginning to be unraveled and here we discuss their roles and interdependence. PMID:28119914

Contribution of mitral valve leaflet length and septal wall thickness to outflow tract obstruction in patients with hypertrophic cardiomyopathy.

Science.gov (United States)

Morant, Kareem; Mikami, Yoko; Nevis, Immaculate; McCarty, David; Stirrat, John; Scholl, David; Rajchl, Martin; Giannoccaro, Peter; Kolman, Louis; Heydari, Bobby; Lydell, Carmen; Howarth, Andrew; Grant, Andrew; White, James A

2017-08-01

We sought to examine whether elongation of the mitral valve leaflets in patients with hypertrophic cardiomyopathy (HCM) is synergistic to septal wall thickness (SWT) in the development of left ventricular outflow tract obstruction (LVOTO). HCM is a common genetic cardiac disease characterized by asymmetric septal hypertrophy and predisposition towards LVOTO. It has been reported that elongation of the mitral valve leaflets may be a primary phenotypic feature and contribute to LVOTO. However, the relative contribution of this finding versus SWT has not been studied. 152 patients (76 with HCM and 76 non-diseased age, race and BSA-matched controls) and 18 young, healthy volunteers were studied. SWT and the anterior mitral valve leaflet length (AMVLL) were measured using cine MRI. The combined contribution of these variables (SWT × AMVLL) was described as the Septal Anterior Leaflet Product (SALP). Peak LVOT pressure gradient was determined by Doppler interrogation and defined as "obstructive" if ≥ 30 mmHg. Patients with HCM were confirmed to have increased AMVLL compared with controls and volunteers (p SALP were significantly higher in patients with LVOTO (N = 17) versus without. SALP showed modest improvement in predictive accuracy for LVOTO (AUC = 0.81) among the HCM population versus SWT alone (AUC = 0.77). However, in isolated patients this variable identified patients with LVOTO despite modest SWT. Elongation of the AMVLL is a primary phenotypic feature of HCM. While incremental contributions to LVOTO appear modest at a population level, specific patients may have dominant contribution to LVOTO. The combined marker of SALP allows for maintained identification of such patients despite modest increases in SWT.

Shelf-life of bioprosthetic heart valves: a structural and mechanical study.

Science.gov (United States)

Julien, M; Létouneau, D R; Marois, Y; Cardou, A; King, M W; Guidoin, R; Chachra, D; Lee, J M

1997-04-01

This study was undertaken to evaluate the influence of storage conditions on the shelf-life of porcine bioprosthetic valves. Fifty-five unimplanted porcine bioprostheses have been evaluated. The valves were stored in 0.5% buffered glutaraldehyde solution for different periods of time (7, 23 and 32 months). Twenty-eight valves were refrigerated while the remaining valves were stored at room temperature. The pH of the glutaraldehyde solution at room temperature decreased with time of storage, while that kept in the refrigerator remained stable over the course of the study. Macroscopic observations showed that the valve tissues kept at room temperature, especially for the periods of 23 and 32 months, became darker and more yellow in colour, whereas the refrigerated specimens exhibited no such changes in appearance. Scanning electron microscopy analysis revealed no noticeable differences on the surfaces of the leaflets stored under different conditions. Mechanical tests, including stress-strain response, stress relaxation and fracture behaviour, were carried out. Analysis of variance showed that the storage temperature, but not the length of storage, had a significant effect on some mechanical properties. The stress relaxation at 1000 s (P = 0.05), the ultimate tensile strength (P = 0.01) and the strain at fracture (P = 0.04) were all higher after storage at room temperature compared to the results after refrigeration. No statistically significant changes in the denaturation temperature of the collagen were observed between the different storage conditions. In conclusion, the storage temperature appears to have some influence on the bioprosthetic tissue. The bioprostheses stored under ambient conditions experience changes which may influence their longterm in vivo performance.

Initial results of combined anterior mitral leaflet extension and myectomy in patients with obstructive hypertrophic cardiomyopathy

NARCIS (Netherlands)

M.J.M. Kofflard (Marcel); L.A. van Herwerden (Lex); D.J. Waldstein; P.N. Ruygrok (Peter); H. Boersma (Eric); M.A. Taams (Meindert); F.J. ten Cate (Folkert)

1996-01-01

textabstractObjectives. The purpose of this study was to describe the clinical and functional results of combined anterior mitral leaflet extension and myectomy in patients with hypertrophic obstructive cardiomyopathy. Background. Septal myectomy is the most commonly performed surgical procedure in

Pathophysiology of Degenerative Mitral Regurgitation: New 3-Dimensional Imaging Insights.

Science.gov (United States)

Antoine, Clemence; Mantovani, Francesca; Benfari, Giovanni; Mankad, Sunil V; Maalouf, Joseph F; Michelena, Hector I; Enriquez-Sarano, Maurice

2018-01-01

Despite its high prevalence, little is known about mechanisms of mitral regurgitation in degenerative mitral valve disease apart from the leaflet prolapse itself. Mitral valve is a complex structure, including mitral annulus, mitral leaflets, papillary muscles, chords, and left ventricular walls. All these structures are involved in physiological and pathological functioning of this valvuloventricular complex but up to now were difficult to analyze because of inherent limitations of 2-dimensional imaging. The advent of 3-dimensional echocardiography, computed tomography, and cardiac magnetic resonance imaging overcoming these limitations provides new insights into mechanistic analysis of degenerative mitral regurgitation. This review will detail the contribution of quantitative and qualitative dynamic analysis of mitral annulus and mitral leaflets by new imaging methods in the understanding of degenerative mitral regurgitation pathophysiology. © 2018 American Heart Association, Inc.

Engineering a 3D-Bioprinted Model of Human Heart Valve Disease Using Nanoindentation-Based Biomechanics

Directory of Open Access Journals (Sweden)

Dewy C. van der Valk

2018-05-01

Full Text Available In calcific aortic valve disease (CAVD, microcalcifications originating from nanoscale calcifying vesicles disrupt the aortic valve (AV leaflets, which consist of three (biomechanically distinct layers: the fibrosa, spongiosa, and ventricularis. CAVD has no pharmacotherapy and lacks in vitro models as a result of complex valvular biomechanical features surrounding resident mechanosensitive valvular interstitial cells (VICs. We measured layer-specific mechanical properties of the human AV and engineered a three-dimensional (3D-bioprinted CAVD model that recapitulates leaflet layer biomechanics for the first time. Human AV leaflet layers were separated by microdissection, and nanoindentation determined layer-specific Young’s moduli. Methacrylated gelatin (GelMA/methacrylated hyaluronic acid (HAMA hydrogels were tuned to duplicate layer-specific mechanical characteristics, followed by 3D-printing with encapsulated human VICs. Hydrogels were exposed to osteogenic media (OM to induce microcalcification, and VIC pathogenesis was assessed by near infrared or immunofluorescence microscopy. Median Young’s moduli of the AV layers were 37.1, 15.4, and 26.9 kPa (fibrosa/spongiosa/ventricularis, respectively. The fibrosa and spongiosa Young’s moduli matched the 3D 5% GelMa/1% HAMA UV-crosslinked hydrogels. OM stimulation of VIC-laden bioprinted hydrogels induced microcalcification without apoptosis. We report the first layer-specific measurements of human AV moduli and a novel 3D-bioprinted CAVD model that potentiates microcalcification by mimicking the native AV mechanical environment. This work sheds light on valvular mechanobiology and could facilitate high-throughput drug-screening in CAVD.

Mechanical transduction via a single soft polymer

Science.gov (United States)

Hou, Ruizheng; Wang, Nan; Bao, Weizhu; Wang, Zhisong

2018-04-01

Molecular machines from biology and nanotechnology often depend on soft structures to perform mechanical functions, but the underlying mechanisms and advantages or disadvantages over rigid structures are not fully understood. We report here a rigorous study of mechanical transduction along a single soft polymer based on exact solutions to the realistic three-dimensional wormlike-chain model and augmented with analytical relations derived from simpler polymer models. The results reveal surprisingly that a soft polymer with vanishingly small persistence length below a single chemical bond still transduces biased displacement and mechanical work up to practically significant amounts. This "soft" approach possesses unique advantages over the conventional wisdom of rigidity-based transduction, and potentially leads to a unified mechanism for effective allosterylike transduction and relay of mechanical actions, information, control, and molecules from one position to another in molecular devices and motors. This study also identifies an entropy limit unique to the soft transduction, and thereby suggests a possibility of detecting higher efficiency for kinesin motor and mutants in future experiments.

Chamber identity programs drive early functional partitioning of the heart.

Science.gov (United States)

Mosimann, Christian; Panáková, Daniela; Werdich, Andreas A; Musso, Gabriel; Burger, Alexa; Lawson, Katy L; Carr, Logan A; Nevis, Kathleen R; Sabeh, M Khaled; Zhou, Yi; Davidson, Alan J; DiBiase, Anthony; Burns, Caroline E; Burns, C Geoffrey; MacRae, Calum A; Zon, Leonard I

2015-08-26

The vertebrate heart muscle (myocardium) develops from the first heart field (FHF) and expands by adding second heart field (SHF) cells. While both lineages exist already in teleosts, the primordial contributions of FHF and SHF to heart structure and function remain incompletely understood. Here we delineate the functional contribution of the FHF and SHF to the zebrafish heart using the cis-regulatory elements of the draculin (drl) gene. The drl reporters initially delineate the lateral plate mesoderm, including heart progenitors. Subsequent myocardial drl reporter expression restricts to FHF descendants. We harnessed this unique feature to uncover that loss of tbx5a and pitx2 affect relative FHF versus SHF contributions to the heart. High-resolution physiology reveals distinctive electrical properties of each heart field territory that define a functional boundary within the single zebrafish ventricle. Our data establish that the transcriptional program driving cardiac septation regulates physiologic ventricle partitioning, which successively provides mechanical advantages of sequential contraction.

Muscle-Specific Mis-Splicing and Heart Disease Exemplified by RBM20.

Science.gov (United States)

Rexiati, Maimaiti; Sun, Mingming; Guo, Wei

2018-01-05

Alternative splicing is an essential post-transcriptional process to generate multiple functional RNAs or proteins from a single transcript. Progress in RNA biology has led to a better understanding of muscle-specific RNA splicing in heart disease. The recent discovery of the muscle-specific splicing factor RNA-binding motif 20 (RBM20) not only provided great insights into the general alternative splicing mechanism but also demonstrated molecular mechanism of how this splicing factor is associated with dilated cardiomyopathy. Here, we review our current knowledge of muscle-specific splicing factors and heart disease, with an emphasis on RBM20 and its targets, RBM20-dependent alternative splicing mechanism, RBM20 disease origin in induced Pluripotent Stem Cells (iPSCs), and RBM20 mutations in dilated cardiomyopathy. In the end, we will discuss the multifunctional role of RBM20 and manipulation of RBM20 as a potential therapeutic target for heart disease.

Evidence that BDNF regulates heart rate by a mechanism involving increased brainstem parasympathetic neuron excitability

OpenAIRE

Wan, Ruiqian; Weigand, Letitia A.; Bateman, Ryan; Griffioen, Kathleen; Mendelowitz, David; Mattson, Mark P.

2014-01-01

Autonomic control of heart rate is mediated by cardioinhibitory parasympathetic cholinergic neurons located in the brainstem and stimulatory sympathetic noradrenergic neurons. During embryonic development the survival and cholinergic phenotype of brainstem autonomic neurons is promoted by brain-derived neurotrophic factor (BDNF). We now provide evidence that BDNF regulates heart rate by a mechanism involving increased brainstem cardioinhibitory parasympathetic activity. Mice with a BDNF haplo...

Single-hit mechanism of tumour cell killing by radiation.

Science.gov (United States)

Chapman, J D

2003-02-01

To review the relative importance of the single-hit mechanism of radiation killing for tumour response to 1.8-2.0 Gy day(-1) fractions and to low dose-rate brachytherapy. Tumour cell killing by ionizing radiation is well described by the linear-quadratic equation that contains two independent components distinguished by dose kinetics. Analyses of tumour cell survival curves that contain six or more dose points usually provide good estimates of the alpha- and beta-inactivation coefficients. Superior estimates of tumour cell intrinsic radiosensitivity are obtained when synchronized populations are employed. The characteristics of single-hit inactivation of tumour cells are reviewed and compared with the characteristics of beta-inactivation. Potential molecular targets associated with single-hit inactivation are discussed along with strategies for potentiating cell killing by this mechanism. The single-hit mechanism of tumour cell killing shows no dependence on dose-rate and, consequently, no evidence of sublethal damage repair. It is uniquely potentiated by high linear-energy-transfer radiation, exhibits a smaller oxygen enhancement ratio and exhibits a larger indirect effect by hydroxyl radicals than the beta-mechanism. alpha-inactivation coefficients vary slightly throughout interphase but mitotic cells exhibit extremely high alpha-coefficients in the range of those observed for lymphocytes and some repair-deficient cells. Evidence is accumulating to suggest that chromatin in compacted form could be a radiation-hypersensitive target associated with single-hit radiation killing. Analyses of tumour cell survival curves demonstrate that it is the single-hit mechanism (alpha) that determines the majority of cell killing after doses of 2Gy and that this mechanism is highly variable between tumour cell lines. The characteristics of single-hit inactivation are qualitatively and quantitatively distinct from those of beta-inactivation. Compacted chromatin in tumour cells

Heart valve surgery

Science.gov (United States)

... replacement; Valve repair; Heart valve prosthesis; Mechanical valves; Prosthetic valves ... surgery. Your heart valve has been damaged by infection ( endocarditis ). You have received a new heart valve ...

Role of vortices in cavitation formation in the flow across a mechanical heart valve.

Science.gov (United States)

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

2008-07-01

Cavitation occurs during mechanical heart valve closure when the local pressure drops below vapor pressure. The formation of stable gas bubbles may result in gaseous emboli, and secondarily cause transient ischemic attacks or strokes. It is noted that instantaneous valve closure, occluder rebound and high-speed leakage flow generate vortices that promote low-pressure regions in favor of stable bubble formation; however, to date no studies have been conducted for the quantitative measurement and analysis of these vortices. A Björk-Shiley Monostrut (BSM) monoleaflet valve was placed in the mitral position of a pulsatile mock circulatory loop. Particle image velocimetry (PIV) and pico coulomb (PCB) pressure measurements were applied. Flow field measurements were carried out at t = -5, -3, -1, -0.5, 0 (valve closure), 0.3, 0.5, 0.75, 1.19, 1.44, 1.69, 1.94, 2, 2.19, 2.54, 2.79, 3.04, 3.29, 3.54, 5 and 10 ms. The vortices were quantitatively analyzed using the Rankine vortex model. A single counter-clockwise vortex was The instantaneous formation of cavitation bubbles at mechanical heart valve (MHV) closure, which subsequently damage blood cells and valve integrity, is a well-known and widely studied phenomenon (1-4). Contributing factors seem to include the water-hammer, squeeze flow and Venturi effects, all of which are short-lived. Both, Dauzat et al. (5) and Sliwka et al. (6) have detected high-intensity transient signals (HITS) with transcranial Doppler ultrasound in the carotid and cerebral arteries of MHV recipients, while Deklunder (7) observed clinical occurrences of cerebral gas emboli that were not seen with bioprosthetic valves. These detected over the major orifice, while a pair of counter-rotating vortices was found over the minor orifice. Velocity profiles were consistent with Rankine vortices. The vortex strength and magnitude of the pressure drop peaked shortly after initial occluder-housing impact and rapidly decreased after 0.5 ms, indicating viscous

Influence of Printed Leaflets on Consumer Purchase Behavior

Directory of Open Access Journals (Sweden)

Jan Huml

2015-01-01

Full Text Available This article deals with the way customers perceive individual non-direct response printed leaflets and it is simultaneously focused on the question whether this material has any importance in general for customers during their purchase realization. The research is further concerned with the issue of the differences between customers living in family built-up areas and those who are living in residential housing. The research explores the differences related to preferences of various target groups. It identifies whether customers wish to receive printed advertising material into their letter boxes, what sort of media they read and what kinds of assortment are most frequently requested to appear in this form of promotion by customers. Preferences are aggregated by means of data classification based on different criteria and they provide a clue for better orientation in customer thinking.

Evaluation of the Readability of Dermatological Postoperative Patient Information Leaflets Across England.

Science.gov (United States)

Hunt, William T N; McGrath, Emily J

2016-06-01

Postoperative patient information leaflets (PILs) provide important guidance to patients after skin surgery. Readability is a method of evaluating information for text comprehension. The recommended level for PIL readability is US grade ≤6. To evaluate the readability of public English dermatological postoperative PILs. All dermatology departments in England were requested to provide their postoperative PILs. Patient information leaflets were evaluated using Readability Studio (Oleander Software, Vandalia, OH). Two preselected parameters were also noted: whether the PIL was doctor or nurse-written, and whether the PIL was Information Standard hallmarked. Eighty-five of one hundred thirty (65.4%) of PILs were evaluated. Only 29.4% of the PILs were grade level ≤6 with Flesch-Kincaid. The mean readability levels were 7.8 for Flesch-Kincaid, 67 for Flesch reading ease, 10.5 for Simple Measure of Gobbledygook (SMOG), 9.4 for Gunning-Fog, 8 for Fry, and 9.8 for FORCAST. No instruments demonstrated a significant difference between doctor (6) and nurse-written (7) PILs. Two instruments found that the 3 Information Standard hallmarked PILs had a higher (harder) readability than ordinary PILs (n = 82) (Gunning-Fog, p = .029*; SMOG p = .049*). Most English postoperative dermatological PILs' readability levels exceed recommendations (US grade ≤6). Departmental PILs should be reviewed to ensure that they are comprehensible to their patients.

Role of long-term mechanical circulatory support in patients with advanced heart failure.

Science.gov (United States)

Stokes, M B; Bergin, P; McGiffin, D

2016-05-01

Advanced heart failure represents a small proportion of patients with heart failure that possess high-risk features associated with high hospital readmission rates, significant functional impairment and mortality. Identification of those who have progressed to, or are near a state of advanced heart failure should prompt referral to a service that offers therapies in mechanical circulatory support (MCS) and cardiac transplantation. MCS has grown as a management strategy in the care of these patients, most commonly as a bridge to cardiac transplantation. The predominant utilisation of MCS is implantation of left ventricular assist devices (LVAD), which have evolved significantly in their technology and application over the past 15-20 years. The technology has evolved to such an extent that Destination Therapy is now being utilised as a strategy in management of advanced heart failure in appropriately selected patients. Complication rates have decreased with VAD implantation, but remain a significant consideration in the decision to implant a device, and in the follow up of these patients. © 2016 Royal Australasian College of Physicians.

ENDURANCE TRAINING AND GLUTATHIONE-DEPENDENT ANTIOXIDANT DEFENSE MECHANISM IN HEART OF THE DIABETIC RATS

Directory of Open Access Journals (Sweden)

Mustafa Atalay

2003-06-01

Full Text Available Regular physical exercise beneficially influences cardiac antioxidant defenses in normal rats. The aim of this study was to test whether endurance training can strengthen glutathione-dependent antioxidant defense mechanism and decrease lipid peroxidation in heart of the streptozotocin-induced diabetic rats. Redox status of glutathione in blood of diabetic rats in response to training and acute exercise was also examined. Eight weeks of treadmill training increased the endurance in streptozotocin-induced diabetic rats. It did not affect glutathione level in heart tissue at rest and also after exercise. On the other hand, endurance training decreased glutathione peroxidase activity in heart, while glutathione reductase and glutathione S-transferase activities were not affected either by acute exhaustive exercise or endurance training. Reduced and oxidized glutathione levels in blood were not affected by either training or acute exercise. Conjugated dienes levels in heart tissue were increased by acute exhaustive exercise and also 8 weeks treadmill training. Longer duration of exhaustion in trained group may have contributed to the increased conjugated dienes levels in heart after acute exercise. Our results suggest that endurance type exercise may make heart more susceptible to oxidative stress. Therefore it may be wise to combine aerobic exercise with insulin treatment to prevent its adverse effects on antioxidant defense in heart in patients with diabetes mellitus

Chronic heat improves mechanical and metabolic response of trained rat heart on ischemia and reperfusion.

Science.gov (United States)

Levy, E; Hasin, Y; Navon, G; Horowitz, M

1997-05-01

Cardiac mechanics and metabolic performance were studied in isolated perfused hearts of rats subjected to a combined chronic stress of heat acclimation and swimming training (EXAC) or swimming training alone (EX). Diastolic (DP) and systolic pressures (SP), coronary flow (CF), and oxygen consumption were measured during normoperfusion (80 mmHg), and the appearance of ischemic contracture (IC), DP, and SP were measured during progressive graded ischemia, total ischemia (TI), and reperfusion insults. ATP, phosphocreatine, and intracellular pH were measured during TI and reperfusion with 31P nuclear magnetic resonance spectroscopy. During normoperfusion, SP and cardiac efficiency (derived from rate-pressure product-oxygen consumption relationships) were the highest in the 2-mo EXAC hearts (P pool and there was a delayed decline in intracellular pH. On reperfusion, these hearts also displayed improved ATP and phosphocreatine recovery, the 2-mo EXAC heart demonstrating significantly faster high-energy phosphate salvage, improved diastolic function, and pulse pressure recovery. The data attest to the beneficial effects of heat acclimation on cardiac mechanics of trained rats during normoperfusion and cardiac protection on ischemia and reperfusion. Possibly, energy sparing, lesser acidosis, and shorter duration of IC on ischemia and improved energy salvage on reperfusion contribute synergistically to this potent beneficial effect.

[Ginseng prescription rules and molecular mechanism in treating coronary heart disease based on data mining and integrative pharmacology].

Science.gov (United States)

Li, Sen; Tang, Shi-Huan; Liu, Jin-Ling; Su, Jin; He, Fu-Yuan

2018-04-01

The ancient dragon Materia Medica, Compendium of Materia Medica and other works recorded that the main effect of ginseng is tonifying qi. It is reported that the main active ingredient of ginseng is ginsenoside. Modern studies have found that ginseng mono saponins are effective for cardiovascular related diseases. This paper preliminary clarified the efficacy of traditional ginseng-nourishing qi and cardiovascular disease through the traditional Chinese medicine (TCM) inheritance auxiliary platform and integration platform of association of pharmacology. With the help of TCM inheritance auxiliary platform-analysis of "Chinese medicine database", Chinese medicine treatment of modern diseases that ginseng rules, so the traditional effect associated with modern medicine and pharmacology; application integration platform enrichment analysis on the target of drug and gene function, metabolic pathway, to further explore the molecular mechanism of ginseng in the treatment of coronary heart disease, aimed at mining the molecular mechanism of ginseng in the treatment of coronary heart disease. Chinese medicine containing ginseng 307 prescriptions, 87 kinds of disease indications, western medicine disease Chinese medicine therapy for ginseng main coronary heart disease; analysis of molecular mechanism of ginseng pharmacology integration platform for the treatment of coronary heart disease. Ginsenosides（Ra₁, Ra₂, Rb₁, Rb₂, Rg₁, Ro) bind these targets, PRKAA1, PRKAA2, NDUFA4, COX5B, UQCRC1, affect chemokines, non-alcoholic fatty liver, gonadotropin, carbon metabolism, glucose metabolism and other pathways to treat coronary heart disease indirectly. The molecular mechanism of Panax ginseng's multi-component, multi-target and synergistic action is preliminarily elucidated in this paper. Copyright© by the Chinese Pharmaceutical Association.

A new construction technique for tissue-engineered heart valves using the self-assembly method.

Science.gov (United States)

Tremblay, Catherine; Ruel, Jean; Bourget, Jean-Michel; Laterreur, Véronique; Vallières, Karine; Tondreau, Maxime Y; Lacroix, Dan; Germain, Lucie; Auger, François A

2014-11-01

Tissue engineering appears as a promising option to create new heart valve substitutes able to overcome the serious drawbacks encountered with mechanical substitutes or tissue valves. The objective of this article is to present the construction method of a new entirely biological stentless aortic valve using the self-assembly method and also a first assessment of its behavior in a bioreactor when exposed to a pulsatile flow. A thick tissue was created by stacking several fibroblast sheets produced with the self-assembly technique. Different sets of custom-made templates were designed to confer to the thick tissue a three-dimensional (3D) shape similar to that of a native aortic valve. The construction of the valve was divided in two sequential steps. The first step was the installation of the thick tissue in a flat preshaping template followed by a 4-week maturation period. The second step was the actual cylindrical 3D forming of the valve. The microscopic tissue structure was assessed using histological cross sections stained with Masson's Trichrome and Picrosirius Red. The thick tissue remained uniformly populated with cells throughout the construction steps and the dense extracellular matrix presented corrugated fibers of collagen. This first prototype of tissue-engineered heart valve was installed in a bioreactor to assess its capacity to sustain a light pulsatile flow at a frequency of 0.5 Hz. Under the light pulsed flow, it was observed that the leaflets opened and closed according to the flow variations. This study demonstrates that the self-assembly method is a viable option for the construction of complex 3D shapes, such as heart valves, with an entirely biological material.

Prognostic importance of left ventricular mechanical dyssynchrony in heart failure with preserved ejection fraction

DEFF Research Database (Denmark)

Biering-Sørensen, Tor; Shah, Sanjiv J; Anand, Inder

2017-01-01

AIMS: Left ventricular mechanical dyssynchrony has been described in heart failure with preserved ejection fraction (HFpEF), but its prognostic significance is not known. METHODS AND RESULTS: Of 3445 patients with HFpEF enrolled in the Treatment of Preserved Cardiac Function Heart Failure...... models assessed the association of dyssynchrony with the composite outcome of cardiovascular death or heart failure hospitalization. Mean age was 70 ± 10 years, LVEF was 60 ± 8%, and QRS duration was 101 ± 27 ms. Worse dyssynchrony, reflected in SD T2P LS, was associated with wider QRS, prior myocardial...... with the composite outcome in unadjusted analysis [hazard ratio (HR) 1.04, 95% confidence interval (CI) 1.01-1.07; P = 0.021, per 10 ms increase], but not after adjusting for clinical characteristics, or after further adjustment for LVEF, AF, NYHA class, stroke, heart rate, creatinine, haematocrit, and QRS duration...

TRPA1 mediates changes in heart rate variability and cardiac mechanical function in mice exposed to acrolein

Energy Technology Data Exchange (ETDEWEB)

Kurhanewicz, Nicole [Curriculum in Toxicology, School of Medicine, University of North Carolina, Chapel Hill, NC 27599 (United States); McIntosh-Kastrinsky, Rachel [Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC 27599 (United States); Tong, Haiyan; Ledbetter, Allen; Walsh, Leon; Farraj, Aimen [Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, US Environmental Protection Agency, Research Triangle Park, NC 27711 (United States); Hazari, Mehdi, E-mail: hazari.mehdi@epa.gov [Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, US Environmental Protection Agency, Research Triangle Park, NC 27711 (United States)

2017-06-01

Short-term exposure to ambient air pollution is linked with adverse cardiovascular effects. While previous research focused primarily on particulate matter-induced responses, gaseous air pollutants also contribute to cause short-term cardiovascular effects. Mechanisms underlying such effects have not been adequately described, however the immediate nature of the response suggests involvement of irritant neural activation and downstream autonomic dysfunction. Thus, this study examines the role of TRPA1, an irritant sensory receptor found in the airways, in the cardiac response of mice to acrolein and ozone. Conscious unrestrained wild-type C57BL/6 (WT) and TRPA1 knockout (KO) mice implanted with radiotelemeters were exposed once to 3 ppm acrolein, 0.3 ppm ozone, or filtered air. Heart rate (HR) and electrocardiogram (ECG) were recorded continuously before, during and after exposure. Analysis of ECG morphology, incidence of arrhythmia and heart rate variability (HRV) were performed. Cardiac mechanical function was assessed using a Langendorff perfusion preparation 24 h post-exposure. Acrolein exposure increased HRV independent of HR, as well as incidence of arrhythmia. Acrolein also increased left ventricular developed pressure in WT mice at 24 h post-exposure. Ozone did not produce any changes in cardiac function. Neither gas produced ECG effects, changes in HRV, arrhythmogenesis, or mechanical function in KO mice. These data demonstrate that a single exposure to acrolein causes cardiac dysfunction through TRPA1 activation and autonomic imbalance characterized by a shift toward parasympathetic modulation. Furthermore, it is clear from the lack of ozone effects that although gaseous irritants are capable of eliciting immediate cardiac changes, gas concentration and properties play important roles. - Highlights: • Acute acrolein exposure causes autonomic imbalance and altered CV function in mice. • TRPA1 mediates acrolein-induced autonomic nervous system cardiac

TRPA1 mediates changes in heart rate variability and cardiac mechanical function in mice exposed to acrolein

International Nuclear Information System (INIS)

Kurhanewicz, Nicole; McIntosh-Kastrinsky, Rachel; Tong, Haiyan; Ledbetter, Allen; Walsh, Leon; Farraj, Aimen; Hazari, Mehdi

2017-01-01

Short-term exposure to ambient air pollution is linked with adverse cardiovascular effects. While previous research focused primarily on particulate matter-induced responses, gaseous air pollutants also contribute to cause short-term cardiovascular effects. Mechanisms underlying such effects have not been adequately described, however the immediate nature of the response suggests involvement of irritant neural activation and downstream autonomic dysfunction. Thus, this study examines the role of TRPA1, an irritant sensory receptor found in the airways, in the cardiac response of mice to acrolein and ozone. Conscious unrestrained wild-type C57BL/6 (WT) and TRPA1 knockout (KO) mice implanted with radiotelemeters were exposed once to 3 ppm acrolein, 0.3 ppm ozone, or filtered air. Heart rate (HR) and electrocardiogram (ECG) were recorded continuously before, during and after exposure. Analysis of ECG morphology, incidence of arrhythmia and heart rate variability (HRV) were performed. Cardiac mechanical function was assessed using a Langendorff perfusion preparation 24 h post-exposure. Acrolein exposure increased HRV independent of HR, as well as incidence of arrhythmia. Acrolein also increased left ventricular developed pressure in WT mice at 24 h post-exposure. Ozone did not produce any changes in cardiac function. Neither gas produced ECG effects, changes in HRV, arrhythmogenesis, or mechanical function in KO mice. These data demonstrate that a single exposure to acrolein causes cardiac dysfunction through TRPA1 activation and autonomic imbalance characterized by a shift toward parasympathetic modulation. Furthermore, it is clear from the lack of ozone effects that although gaseous irritants are capable of eliciting immediate cardiac changes, gas concentration and properties play important roles. - Highlights: • Acute acrolein exposure causes autonomic imbalance and altered CV function in mice. • TRPA1 mediates acrolein-induced autonomic nervous system cardiac

The total artificial heart.

Science.gov (United States)

Cook, Jason A; Shah, Keyur B; Quader, Mohammed A; Cooke, Richard H; Kasirajan, Vigneshwar; Rao, Kris K; Smallfield, Melissa C; Tchoukina, Inna; Tang, Daniel G

2015-12-01

The total artificial heart (TAH) is a form of mechanical circulatory support in which the patient's native ventricles and valves are explanted and replaced by a pneumatically powered artificial heart. Currently, the TAH is approved for use in end-stage biventricular heart failure as a bridge to heart transplantation. However, with an increasing global burden of cardiovascular disease and congestive heart failure, the number of patients with end-stage heart failure awaiting heart transplantation now far exceeds the number of available hearts. As a result, the use of mechanical circulatory support, including the TAH and left ventricular assist device (LVAD), is growing exponentially. The LVAD is already widely used as destination therapy, and destination therapy for the TAH is under investigation. While most patients requiring mechanical circulatory support are effectively treated with LVADs, there is a subset of patients with concurrent right ventricular failure or major structural barriers to LVAD placement in whom TAH may be more appropriate. The history, indications, surgical implantation, post device management, outcomes, complications, and future direction of the TAH are discussed in this review.

Action potential-evoked calcium release is impaired in single skeletal muscle fibers from heart failure patients.

Directory of Open Access Journals (Sweden)

Marino DiFranco

Full Text Available Exercise intolerance in chronic heart failure (HF has been attributed to abnormalities of the skeletal muscles. Muscle function depends on intact excitation-contraction coupling (ECC, but ECC studies in HF models have been inconclusive, due to deficiencies in the animal models and tools used to measure calcium (Ca2+ release, mandating investigations in skeletal muscle from HF patients. The purpose of this study was to test the hypothesis that Ca2+ release is significantly impaired in the skeletal muscle of HF patients in whom exercise capacity is severely diminished compared to age-matched healthy volunteers.Using state-of-the-art electrophysiological and optical techniques in single muscle fibers from biopsies of the locomotive vastus lateralis muscle, we measured the action potential (AP-evoked Ca2+ release in 4 HF patients and 4 age-matched healthy controls. The mean peak Ca2+ release flux in fibers obtained from HF patients (10±1.2 µM/ms was markedly (2.6-fold and significantly (p<0.05 smaller than in fibers from healthy volunteers (28±3.3 µM/ms. This impairment in AP-evoked Ca2+ release was ubiquitous and was not explained by differences in the excitability mechanisms since single APs were indistinguishable between HF patients and healthy volunteers.These findings prove the feasibility of performing electrophysiological experiments in single fibers from human skeletal muscle, and offer a new approach for investigations of myopathies due to HF and other diseases. Importantly, we have demonstrated that one step in the ECC process, AP-evoked Ca2+ release, is impaired in single muscle fibers in HF patients.

Posters y trípticos (Brochures) en LATEX con Beamer y Leaflet

OpenAIRE

Borbón, Alexánder

2013-01-01

Resumen. En este artículo se muestra la manera en que se puede realizar posters y trípticos (panfletos o brochures) con LATEX. Para realizar los posters se utiliza la clase beamer que usualmente se utiliza para hacer presentaciones, se utiliza el paquete beamerposter para poder utilizarla para posters. Los trípticos se realizan de dos formas, la primera utilizando la clase beamer con el paquete geometry y la segunda utilizando la clase leaflet que es una clase especializada para hacer este ti...

Calcium-dependent arrhythmias in transgenic mice with heart failure.

Science.gov (United States)

London, Barry; Baker, Linda C; Lee, Joon S; Shusterman, Vladimir; Choi, Bum-Rak; Kubota, Toru; McTiernan, Charles F; Feldman, Arthur M; Salama, Guy

2003-02-01

Transgenic mice overexpressing the inflammatory cytokine tumor necrosis factor (TNF)-alpha (TNF-alpha mice) in the heart develop a progressive heart failure syndrome characterized by biventricular dilatation, decreased ejection fraction, atrial and ventricular arrhythmias on ambulatory telemetry monitoring, and decreased survival compared with nontransgenic littermates. Programmed stimulation in vitro with single extra beats elicits reentrant ventricular arrhythmias in TNF-alpha (n = 12 of 13 hearts) but not in control hearts. We performed optical mapping of voltage and Ca(2+) in isolated perfused ventricles of TNF-alpha mice to study the mechanisms that lead to the initiation and maintenance of the arrhythmias. When compared with controls, hearts from TNF-alpha mice have prolonged of action potential durations (action potential duration at 90% repolarization: 23 +/- 2 ms, n = 7, vs. 18 +/- 1 ms, n = 5; P < 0.05), no increased dispersion of refractoriness between apex and base, elevated diastolic and depressed systolic [Ca(2+)], and prolonged Ca(2+) transients (72 +/- 6 ms, n = 10, vs. 54 +/- 5 ms, n = 8; P < 0.01). Premature beats have diminished action potential amplitudes and conduct in a slow, heterogeneous manner. Lowering extracellular [Ca(2+)] normalizes conduction and prevents inducible arrhythmias. Thus both action potential prolongation and abnormal Ca(2+) handling may contribute to the initiation of reentrant arrhythmias in this heart failure model by mechanisms distinct from enhanced dispersion of refractoriness or triggered activity.

Mechanism of the superior mechanical strength of nanometer-sized metal single crystals revealed

KAUST Repository

Afify, N. D.; Salem, H. G.; Yavari, A.; El Sayed, Tamer S.

2013-01-01

Clear understanding of the superior mechanical strength of nanometer-sized metal single crystals is required to derive advanced mechanical components retaining such superiority. Although high quality studies have been reported on nano

Atherosclerotic Cardiovascular Disease and Heart Failure in Type 2 Diabetes – Mechanisms, Management, and Clinical Considerations

Science.gov (United States)

Low Wang, Cecilia C.; Hess, Connie N.; Hiatt, William R.; Goldfine, Allison B.

2016-01-01

Cardiovascular disease remains the principal cause of death and disability among patients with diabetes mellitus. Diabetes exacerbates mechanisms underlying atherosclerosis and heart failure. Unfortunately, these mechanisms are not adequately modulated by therapeutic strategies focusing solely on optimal glycemic control with currently available drugs or approaches. In the setting of multi-factorial risk reduction with statins and other lipid lowering agents, anti-hypertensive therapies, and anti-hyperglycemic treatment strategies, cardiovascular complication rates are falling, yet remain higher for patients with diabetes than for those without. This review considers the mechanisms, history, controversies, new pharmacologic agents, and recent evidence for current guidelines for cardiovascular management in the patient with diabetes mellitus to support evidence-based care in the patient with diabetes and heart disease outside of the acute care setting. PMID:27297342

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

Science.gov (United States)

Mart, Christopher Robin; Eckhauser, Aaron Wesley; Murri, Michael; Su, Jason Thomas

2014-09-01

With surgical palliation of hypoplastic left heart syndrome (HLHS), the tricuspid valve (TV) becomes the systemic atrioventricular valve and moderate/severe TV insufficiency (TVI), an adverse risk factor for survival to Fontan, has been reported in up to 35% of patients prior to stage I palliation. Precise echocardiographic identification of the mechanism of TVI cannot be determined by two-dimensional echocardiography. Three-dimensional echocardiography (3DE) can provide significant insight into the mechanisms of TVI. It is the intent of this report to propose a systematic method on how to evaluate and display 3DE images of the TV in HLHS which has not been done previously. TV anatomy, function, and the known mechanisms of insufficiency are reviewed. We defined three regions of the TV (anterior, posterior, septal) that can help define valve "leaflets" that incorporates the many variations of TV anatomy. To determine how the surgeon views the TV, a picture of a pathologic specimen of the TV was placed on a computer screen and rotated until it was oriented as it appears during surgery, the "surgeons view." 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.

Mechanical circulatory assist device development at the Texas Heart Institute: a personal perspective.

Science.gov (United States)

Frazier, O H

2014-01-01

In December 2013, we performed our 1000th ventricular assist device implantation at the Texas Heart Institute. In my professional career, I have been fortunate to see the development of numerous mechanical circulatory support devices for the treatment of patients with advanced heart failure. In fact, most of the cardiac pumps in wide use today were developed in the Texas Heart Institute research laboratories in cooperation with the National Heart, Lung and Blood Institute or device innovators and manufacturers and implanted clinically at our partner St. Luke's Episcopal Hospital. My early involvement in this field was guided by my mentors, Dr Michael E. DeBakey and, especially, Dr Denton A. Cooley. Also, many of the advances are directly attributable to my ongoing clinical experience. What I learned daily in my surgical practice allowed me to bring insights to the development of this technology that a laboratory researcher alone might not have had. Young academic surgeons interested in this field might be well served to be active not only in laboratory research but also in clinical practice. Copyright © 2014 Elsevier Inc. All rights reserved.

Congenital heart disease and genetic syndromes: new insights into molecular mechanisms.

Science.gov (United States)

Calcagni, Giulio; Unolt, Marta; Digilio, Maria Cristina; Baban, Anwar; Versacci, Paolo; Tartaglia, Marco; Baldini, Antonio; Marino, Bruno

2017-09-01

Advances in genetics allowed a better definition of the role of specific genetic background in the etiology of syndromic congenital heart defects (CHDs). The identification of a number of disease genes responsible for different syndromes have led to the identification of several transcriptional regulators and signaling transducers and modulators that are critical for heart morphogenesis. Understanding the genetic background of syndromic CHDs allowed a better characterization of the genetic basis of non-syndromic CHDs. In this sense, the well-known association of typical CHDs in Down syndrome, 22q11.2 microdeletion and Noonan syndrome represent paradigms as chromosomal aneuploidy, chromosomal microdeletion and intragenic mutation, respectively. Area covered: For each syndrome the anatomical features, distinctive cardiac phenotype and molecular mechanisms are discussed. Moreover, the authors include recent genetic findings that may shed light on some aspects of still unclear molecular mechanisms of these syndromes. Expert commentary: Further investigations are needed to enhance the translational approach in the field of genetics of CHDs. When there is a well-established definition of genotype-phenotype (reverse medicine) and genotype-prognosis (predictive and personalized medicine) correlations, hopefully preventive medicine will make its way in this field. Subsequently a reduction will be achieved in the morbidity and mortality of children with CHDs.

Communicating the benefits and harms of colorectal cancer screening needed for an informed choice: a systematic evaluation of leaflets and booklets.

Science.gov (United States)

Dreier, Maren; Borutta, Birgit; Seidel, Gabriele; Münch, Inga; Kramer, Silke; Töppich, Jürgen; Dierks, Marie-Luise; Walter, Ulla

2014-01-01

Evidence-based health information (EBHI) can support informed choice regarding whether or not to attend colorectal cancer (CRC) screening. The present study aimed to assess if German leaflets and booklets appropriately inform consumers on the benefits and harms of CRC screening. A systematic search for print media on CRC screening was performed via email enquiry and internet search. The identified documents were assessed for the presence and correctness of information on benefits and harms by two reviewers independently using a comprehensive list of criteria. Many of the 28 leaflets and 13 booklets identified presented unbalanced information on the benefits and harms of CRC screening: one-third did not provide any information on harms. Numeracy information was often lacking. Ten cross-language examples of common misinterpretations or basically false and misleading information were identified. Most of the CRC screening leaflets and booklets in Germany do not meet current EBHI standards. After the study, the publishers of the information materials were provided feedback, including a discussion of our findings. The results can be used to revise existing information materials or to develop new materials that provide correct, balanced, quantified, understandable and unbiased information on CRC screening.

Communicating the benefits and harms of colorectal cancer screening needed for an informed choice: a systematic evaluation of leaflets and booklets.

Directory of Open Access Journals (Sweden)

Maren Dreier

Full Text Available Evidence-based health information (EBHI can support informed choice regarding whether or not to attend colorectal cancer (CRC screening. The present study aimed to assess if German leaflets and booklets appropriately inform consumers on the benefits and harms of CRC screening.A systematic search for print media on CRC screening was performed via email enquiry and internet search. The identified documents were assessed for the presence and correctness of information on benefits and harms by two reviewers independently using a comprehensive list of criteria.Many of the 28 leaflets and 13 booklets identified presented unbalanced information on the benefits and harms of CRC screening: one-third did not provide any information on harms. Numeracy information was often lacking. Ten cross-language examples of common misinterpretations or basically false and misleading information were identified.Most of the CRC screening leaflets and booklets in Germany do not meet current EBHI standards. After the study, the publishers of the information materials were provided feedback, including a discussion of our findings. The results can be used to revise existing information materials or to develop new materials that provide correct, balanced, quantified, understandable and unbiased information on CRC screening.

Incidental finding of single coronary artery in a patient with alcoholic cardiomyopathy presenting as acute heart failure.

Science.gov (United States)

McNair, Patrick; Jones, Erica; Truong, Quynh; Singh, Harsimran

Single coronary artery is a rare clinical finding. Diagnosis is typically made incidentally after the patient presents with symptoms and undergoes coronary angiography, coronary computed tomography angiography (CTA), or post-mortem during autopsy. Several high-risk features of anomalous coronary arteries have been described in the literature. Our paper describes a case of dilated alcoholic cardiomyopathy presenting as heart failure with diagnostic workup incidentally revealing single coronary artery. Copyright © 2017 Elsevier Inc. All rights reserved.

Heart Rate Variability: New Perspectives on Physiological Mechanisms, Assessment of Self-regulatory Capacity, and Health risk.

Science.gov (United States)

McCraty, Rollin; Shaffer, Fred

2015-01-01

Heart rate variability, the change in the time intervals between adjacent heartbeats, is an emergent property of interdependent regulatory systems that operates on different time scales to adapt to environmental and psychological challenges. This article briefly reviews neural regulation of the heart and offers some new perspectives on mechanisms underlying the very low frequency rhythm of heart rate variability. Interpretation of heart rate variability rhythms in the context of health risk and physiological and psychological self-regulatory capacity assessment is discussed. The cardiovascular regulatory centers in the spinal cord and medulla integrate inputs from higher brain centers with afferent cardiovascular system inputs to adjust heart rate and blood pressure via sympathetic and parasympathetic efferent pathways. We also discuss the intrinsic cardiac nervous system and the heart-brain connection pathways, through which afferent information can influence activity in the subcortical, frontocortical, and motor cortex areas. In addition, the use of real-time HRV feedback to increase self-regulatory capacity is reviewed. We conclude that the heart's rhythms are characterized by both complexity and stability over longer time scales that reflect both physiological and psychological functional status of these internal self-regulatory systems.

Validation and potential mechanisms of red cell distribution width as a prognostic marker in heart failure.

Science.gov (United States)

Allen, Larry A; Felker, G Michael; Mehra, Mandeep R; Chiong, Jun R; Dunlap, Stephanie H; Ghali, Jalal K; Lenihan, Daniel J; Oren, Ron M; Wagoner, Lynne E; Schwartz, Todd A; Adams, Kirkwood F

2010-03-01

Adverse outcomes have recently been linked to elevated red cell distribution width (RDW) in heart failure. Our study sought to validate the prognostic value of RDW in heart failure and to explore the potential mechanisms underlying this association. Data from the Study of Anemia in a Heart Failure Population (STAMINA-HFP) registry, a prospective, multicenter cohort of ambulatory patients with heart failure supported multivariable modeling to assess relationships between RDW and outcomes. The association between RDW and iron metabolism, inflammation, and neurohormonal activation was studied in a separate cohort of heart failure patients from the United Investigators to Evaluate Heart Failure (UNITE-HF) Biomarker registry. RDW was independently predictive of outcome (for each 1% increase in RDW, hazard ratio for mortality 1.06, 95% CI 1.01-1.12; hazard ratio for hospitalization or mortality 1.06; 95% CI 1.02-1.10) after adjustment for other covariates. Increasing RDW correlated with decreasing hemoglobin, increasing interleukin-6, and impaired iron mobilization. Our results confirm previous observations that RDW is a strong, independent predictor of adverse outcome in chronic heart failure and suggest elevated RDW may indicate inflammatory stress and impaired iron mobilization. These findings encourage further research into the relationship between heart failure and the hematologic system. Copyright (c) 2010 Elsevier Inc. All rights reserved.

The mechanism distinguishability problem in biochemical kinetics: the single-enzyme, single-substrate reaction as a case study.

Science.gov (United States)

Schnell, Santiago; Chappell, Michael J; Evans, Neil D; Roussel, Marc R

2006-01-01

A theoretical analysis of the distinguishability problem of two rival models of the single enzyme-single substrate reaction, the Michaelis-Menten and Henri mechanisms, is presented. We also outline a general approach for analysing the structural indistinguishability between two mechanisms. The approach involves constructing, if possible, a smooth mapping between the two candidate models. Evans et al. [N.D. Evans, M.J. Chappell, M.J. Chapman, K.R. Godfrey, Structural indistinguishability between uncontrolled (autonomous) nonlinear analytic systems, Automatica 40 (2004) 1947-1953] have shown that if, in addition, either of the mechanisms satisfies a particular criterion then such a transformation always exists when the models are indistinguishable from their experimentally observable outputs. The approach is applied to the single enzyme-single substrate reaction mechanism. In principle, mechanisms can be distinguished using this analysis, but we show that our ability to distinguish mechanistic models depends both on the precise measurements made, and on our knowledge of the system prior to performing the kinetics experiments.

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

Science.gov (United States)

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

2016-02-01

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

Late radiation-induced heart disease after radiotherapy. Clinical importance, radiobiological mechanisms and strategies of prevention

International Nuclear Information System (INIS)

Andratschke, Nicolaus; Maurer, Jean; Molls, Michael; Trott, Klaus-Ruediger

2011-01-01

The clinical importance of radiation-induced heart disease, in particular in post-operative radiotherapy of breast cancer patients, has been recognised only recently. There is general agreement, that a co-ordinated research effort would be needed to explore all the potential strategies of how to reduce the late risk of radiation-induced heart disease in radiotherapy. This approach would be based, on one hand, on a comprehensive understanding of the radiobiological mechanisms of radiation-induced heart disease after radiotherapy which would require large-scale long-term animal experiments with high precision local heart irradiation. On the other hand - in close co-operation with mechanistic in vivo research studies - clinical studies in patients need to determine the influence of dose distribution in the heart on the risk of radiation-induced heart disease. The aim of these clinical studies would be to identify the critical structures within the organ which need to be spared and their radiation sensitivity as well as a potential volume and dose effect. The results of the mechanistic studies might also provide concepts of how to modify the gradual progression of radiation damage in the heart by drugs or biological molecules. The results of the studies in patients would need to also incorporate detailed dosimetric and imaging studies in order to develop early indicators of impending radiation-induced heart disease which would be a pre-condition to develop sound criteria for treatment plan optimisation.

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.

A genome resource to address mechanisms of developmental programming: determination of the fetal sheep heart transcriptome.

Science.gov (United States)

Cox, Laura A; Glenn, Jeremy P; Spradling, Kimberly D; Nijland, Mark J; Garcia, Roy; Nathanielsz, Peter W; Ford, Stephen P

2012-06-15

The pregnant sheep has provided seminal insights into reproduction related to animal and human development (ovarian function, fertility, implantation, fetal growth, parturition and lactation). Fetal sheep physiology has been extensively studied since 1950, contributing significantly to the basis for our understanding of many aspects of fetal development and behaviour that remain in use in clinical practice today. Understanding mechanisms requires the combination of systems approaches uniquely available in fetal sheep with the power of genomic studies. Absence of the full range of sheep genomic resources has limited the full realization of the power of this model, impeding progress in emerging areas of pregnancy biology such as developmental programming. We have examined the expressed fetal sheep heart transcriptome using high-throughput sequencing technologies. In so doing we identified 36,737 novel transcripts and describe genes, gene variants and pathways relevant to fundamental developmental mechanisms. Genes with the highest expression levels and with novel exons in the fetal heart transcriptome are known to play central roles in muscle development. We show that high-throughput sequencing methods can generate extensive transcriptome information in the absence of an assembled and annotated genome for that species. The gene sequence data obtained provide a unique genomic resource for sheep specific genetic technology development and, combined with the polymorphism data, augment annotation and assembly of the sheep genome. In addition, identification and pathway analysis of novel fetal sheep heart transcriptome splice variants is a first step towards revealing mechanisms of genetic variation and gene environment interactions during fetal heart development.

False Heart Rate Feedback and the Perception of Heart Symptoms in Patients with Congenital Heart Disease and Anxiety

NARCIS (Netherlands)

Karsdorp, Petra A.; Kindt, Merel; Rietveld, Simon; Everaerd, Walter; Mulder, Barbara J. M.

2009-01-01

Background Little is known about the mechanisms explaining an increased perception of heart symptoms in congenital heart disease (ConHD). In the present study, it was suggested that a combination of high trait anxiety and disease history increases the perception of heart symptoms. Purpose It was

False heart rate feedback and the perception of heart symptoms in patients with congenital heart disease and anxiety

NARCIS (Netherlands)

Karsdorp, P.A.; Kindt, M.; Rietveld, S.; Everaerd, W.; Mulder, B.J.M.

2009-01-01

Background: Little is known about the mechanisms explaining an increased perception of heart symptoms in congenital heart disease (ConHD). In the present study, it was suggested that a combination of high trait anxiety and disease history increases the perception of heart symptoms. Purpose: It was

Air Quality and Heart Health: An Emerging Topic for Heart Month

Science.gov (United States)

Air Quality and Heart Health: An Emerging Topic for Heart Month: Ambient air particle pollution increases short- and long-term cardiovascular morbidity and mortality. Older-people, those with pre-existing heart disease and lung disease and diabetes are at higher risk. Mechanism...

The pathophysiology of heart failure.

Science.gov (United States)

Kemp, Clinton D; Conte, John V

2012-01-01

Heart failure is a clinical syndrome that results when the heart is unable to provide sufficient blood flow to meet metabolic requirements or accommodate systemic venous return. This common condition affects over 5 million people in the United States at a cost of $10-38 billion per year. Heart failure results from injury to the myocardium from a variety of causes including ischemic heart disease, hypertension, and diabetes. Less common etiologies include cardiomyopathies, valvular disease, myocarditis, infections, systemic toxins, and cardiotoxic drugs. As the heart fails, patients develop symptoms which include dyspnea from pulmonary congestion, and peripheral edema and ascites from impaired venous return. Constitutional symptoms such as nausea, lack of appetite, and fatigue are also common. There are several compensatory mechanisms that occur as the failing heart attempts to maintain adequate function. These include increasing cardiac output via the Frank-Starling mechanism, increasing ventricular volume and wall thickness through ventricular remodeling, and maintaining tissue perfusion with augmented mean arterial pressure through activation of neurohormonal systems. Although initially beneficial in the early stages of heart failure, all of these compensatory mechanisms eventually lead to a vicious cycle of worsening heart failure. Treatment strategies have been developed based upon the understanding of these compensatory mechanisms. Medical therapy includes diuresis, suppression of the overactive neurohormonal systems, and augmentation of contractility. Surgical options include ventricular resynchronization therapy, surgical ventricular remodeling, ventricular assist device implantation, and heart transplantation. Despite significant understanding of the underlying pathophysiological mechanisms in heart failure, this disease causes significant morbidity and carries a 50% 5-year mortality. Copyright © 2012 Elsevier Inc. All rights reserved.

Pre-mRNA mis-splicing of sarcomeric genes in heart failure.

Science.gov (United States)

Zhu, Chaoqun; Chen, Zhilong; Guo, Wei

2017-08-01

Pre-mRNA splicing is an important biological process that allows production of multiple proteins from a single gene in the genome, and mainly contributes to protein diversity in eukaryotic organisms. Alternative splicing is commonly governed by RNA binding proteins to meet the ever-changing demands of the cell. However, the mis-splicing may lead to human diseases. In the heart of human, mis-regulation of alternative splicing has been associated with heart failure. In this short review, we focus on alternative splicing of sarcomeric genes and review mis-splicing related heart failure with relatively well studied Sarcomeric genes and splicing mechanisms with identified regulatory factors. The perspective of alternative splicing based therapeutic strategies in heart failure has also been discussed. Copyright © 2016 Elsevier B.V. All rights reserved.

Anticoagulation in pregnant females with mechanical heart valves

International Nuclear Information System (INIS)

Shafique, H.; Chaudhry, A.; Ayyub, M.

2006-01-01

To evaluate the complications and outcome of anticoagulation therapy in pregnant females with valvular heart diseases. All pregnant females with prosthetic heart valves admitted in Armed Forces Institute of Cardiology from Jan 2004 to Dec 2004 were included in this study Basic demographic data including age, duration of pregnancy and complications observed were recorded. Warfarin was replaced with un-fractionated heparin (UFH) in first trimester and after that warfarin was continued with a targeted INR between 2.0-3.0. At 36 weeks warfarin was stopped and UFH was added; however, if patient went into spontaneous labour before this then immediate caesarian section was performed and UFH was restarted 4-6 hours after delivery along with oral warfarin. Out of 21 patients, sixteen (76.1%) had mitral valve diseases and five (23.9%) had both mitral and atrial. Majority (42.3%)of patients were in age group 26-30 years. Eleven (52.2%) reported in 9th month of gestation. Complications observed were hypertension (1), transient ischaemic attacks (1), pulmonary embolism (1), haemoptysis (1) and abortion (1). All patients, except one had successful completion of pregnancy. No case of foetal abnormality was seen. In 76% patients, daily dose of warfarin was <5 mg. Thrombo-prophylaxis in pregnancy with warfarin and UFH with an INR of 2.0-3.0 is effective in preventing thrombotic complications in females with mechanical valves without resulting in increase hemorrhagic complications. (author)

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 conventionally managed heart valve patients (control group) was used as reference. Results: The median observation time was 1175 days (range: 174–1428 days). The self-managed patients were within therapeutic INR target range for a mean of 78.0% (range: 36.1%–93.9%) of the time compared with 61.0% (range 37...

The renal nerves in chronic heart failure: efferent and afferent mechanisms

Science.gov (United States)

Schiller, Alicia M.; Pellegrino, Peter R.; Zucker, Irving H.

2015-01-01

The function of the renal nerves has been an area of scientific and medical interest for many years. The recent advent of a minimally invasive catheter-based method of renal denervation has renewed excitement in understanding the afferent and efferent actions of the renal nerves in multiple diseases. While hypertension has been the focus of much this work, less attention has been given to the role of the renal nerves in the development of chronic heart failure (CHF). Recent studies from our laboratory and those of others implicate an essential role for the renal nerves in the development and progression of CHF. Using a rabbit tachycardia model of CHF and surgical unilateral renal denervation, we provide evidence for both renal efferent and afferent mechanisms in the pathogenesis of CHF. Renal denervation prevented the decrease in renal blood flow observed in CHF while also preventing increases in Angiotensin-II receptor protein in the microvasculature of the renal cortex. Renal denervation in CHF also reduced physiological markers of autonomic dysfunction including an improvement in arterial baroreflex function, heart rate variability, and decreased resting cardiac sympathetic tone. Taken together, the renal sympathetic nerves are necessary in the pathogenesis of CHF via both efferent and afferent mechanisms. Additional investigation is warranted to fully understand the role of these nerves and their role as a therapeutic target in CHF. PMID:26300788

Surgical repair of tricuspid valve leaflet tear following percutaneous closure of perimembranous ventricular septal defect using Amplatzer duct occluder I: Report of two cases

Directory of Open Access Journals (Sweden)

Saatchi Mahesh Kuwelker

2017-01-01

Full Text Available Tricuspid valve (TV injury following transcatheter closure of perimembranous ventricular septal defect (PMVSD with Amplatzer ductal occluder I (ADO I, requiring surgical repair, is rare. We report two cases of TV tear involving the anterior and septal leaflets following PMVSD closure using ADO I. In both the patients, the subvalvular apparatus remained unaffected. The patients presented with severe tricuspid regurgitation (TR 6 weeks and 3 months following the device closure. They underwent surgical repair with patch augmentation of the TV leaflets. Postoperatively, both are asymptomatic with a mild residual TR.

A new generation of high flex life polyurethane urea for polymer heart valve--studies on in vivo biocompatibility and biodurability.

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Thomas, Vinoy; Jayabalan, Muthu

2009-04-01

Development of new generation high flex life polyurethane urea (HFL18-PU) with appropriate elastic modulus, biocompatibility, blood compatibility, resistant to calcification, and biodurability for the long-term use as cardiac device is still a challenge. This study reports the development of a fully aliphatic, ether-free physically cross-linked and low elastic modulus (6.841 +/- 0.27 MPa) polyurethane urea having in vivo biostability, in vivo biocompatibility and high flex-life (721 +/- 30 million cycles) that can satisfy the requirements for the fabrication of tri-leaflet heart valve. Copyright 2008 Wiley Periodicals, Inc.

Women-specific risk factors for heart failure: A genetic approach.

Science.gov (United States)

van der Kemp, Jet; van der Schouw, Yvonne T; Asselbergs, Folkert W; Onland-Moret, N Charlotte

2018-03-01

Heart failure is a complex disease, which is presented differently by men and women. Several studies have shown that reproductive factors, such as age at natural menopause, parity and polycystic ovarian syndrome (PCOS), may play a role in the development of heart failure. Shared genetics may provide clues to underlying mechanisms; however, this has never been examined. Therefore, the aim of the current study was to explore whether any reproductive factor is potentially related to heart failure in women, based on genetic similarities. Conducting a systematic literature review, single nucleotide polymorphisms (SNPs) associated with reproductive factors, heart failure and its risk factors were extracted from recent genome-wide association studies. We tested whether there was any overlap between the SNPs and their proxies of reproductive risk factors with those known for heart failure or its risk factors. In total, 520 genetic variants were found that are associated with reproductive factors, namely age at menarche, age at natural menopause, menstrual cycle length, PCOS, preeclampsia, preterm delivery and spontaneous dizygotic twinning. For heart failure and associated phenotypes, 25 variants were found. Genetic variants for reproductive factors did not overlap with those for heart failure. However, age at menarche, gestational diabetes and PCOS were found to be genetically linked to risk factors for heart failure, such as atrial fibrillation, diabetes and smoking. Corresponding implicated genes, such as TNNI3K, ErbB3, MKL2, MTNR1B and PRKD1, may explain the associations between reproductive factors and heart failure. Exact effector mechanisms of these genes remain to be investigated further. Copyright © 2017. Published by Elsevier B.V.

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

Influence of three mechanical bileaflet prosthetic valve designs on the three-dimensional flow field inside a simulated aorta.

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Akutsu, Toshinosuke; Matsumoto, Akira

2010-12-01

The current design of the bileaflet valve, the leaflets of which open outside first, differs significantly from the natural valve whose leaflets open center first. This difference generates a completely different flow field in the bileaflet valve compared to that in the natural heart valve. In a previous study, it was demonstrated that the valve design greatly affects the aortic flow field as well as the circulatory flow inside sinuses of Valsalva, using saline solution as a working fluid. A limited discussion on the turbulence flow field that could be generated by the valve was provided. In this continuation of that study, therefore, a dynamic PIV study was conducted to analyze the influence of the heart valve design on the aortic flow field, and particularly on the turbulent profile. This study also aimed to determine the influence of the viscosity of the testing fluid. Three bileaflet prostheses-the St. Jude Medical (SJM), the On-X, and the MIRA valves-were tested under pulsatile flow conditions. Flow through the central orifice of the SJM valve was slower than that through the newer designs. The newer designs tend to show strong flow through all orifices. The On-X valve generates simple jet-type flow while the MIRA valve with circumferentially curved leaflets generates a strong but three-dimensionally diffuse flow, resulting in a more complex flow field downstream of the aortic valve with higher turbulence. A 180° orientation that is more popular clinically seems to provide a less diffuse flow than a 90° orientation. The effect of increasing the viscosity was found to be an increase in the flow velocity through the central orifice and a more organized flow field for all of the valves tested.

Is thrombosis a contributor to heart failure pathophysiology? Possible mechanisms, therapeutic opportunities, and clinical investigation challenges

NARCIS (Netherlands)

Zannad, F.; Stough, W.G.; Regnault, V.; Gheorghiade, M.; Deliargyris, E.; Gibson, C.M.; Agewall, S.; Berkowitz, S.D.; Burton, P.; Calvo, G.; Goldstein, S.; Verheugt, F.W.A.; Koglin, J.; O'Connor, C.M.

2013-01-01

Thrombotic events (coronary thrombosis, venous thromboembolism, intraventricular thrombosis, intracranial and systemic thromboembolism) occur frequently in patients with heart failure. These events may be precipitated by several mechanisms including hypercoagulability through enhancement of

Left ventricular remodeling in the post-infarction heart: a review of cellular, molecular mechanisms, and therapeutic modalities.

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Gajarsa, Jason J; Kloner, Robert A

2011-01-01

As more patients survive myocardial infarctions, the incidence of heart failure increases. After an infarction, the human heart undergoes a series of structural changes, which are governed by cellular and molecular mechanisms in a pathological metamorphosis termed "remodeling." This review will discuss the current developments in our understanding of these molecular and cellular events in remodeling and the various pharmacological, cellular and device therapies used to treat, and potentially retard, this condition. Specifically, this paper will examine the neurohormonal activity of the renin-angiotensin-aldosterone axis and its molecular effects on the heart. The emerging understanding of the extra-cellular matrix and the various active molecules within it, such as the matrix metalloproteinases, elicits new appreciation for their role in cardiac remodeling and as possible future therapeutic targets. Cell therapy with stem cells is another recent therapy with great potential in improving post-infarcted hearts. Lastly, the cellular and molecular effects of left ventricular assist devices on remodeling will be reviewed. Our increasing knowledge of the cellular and molecular mechanisms underlying cardiac remodeling enables us not only to better understand how our more successful therapies, like angiotensin-converting enzyme inhibitors, work, but also to explore new therapies of the future.

Atrial Fibrillation Following Surgical Management of Ischemic Heart Disease; One Year, Single Center, Single Surgeon Results

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Ahmet Barış Durukan

2012-08-01

Full Text Available Introduction: Postoperative atrial fibrillation is the most common arrhythmia following bypasssurgery with significant morbidity, mortality and increased healthcare costs. The aim of this studyis to determine the incidence and timing of atrial fibrillation, identify the risk factors coveringpreoperative and intraoperative periods, evaluate rate of return to sinus rhythm by disharge, andexplore the impact on postoperative outcomes in a large group of patients operated in a singlecenter by a single surgeon.Patients and Methods: Between January 2011 and January 2012, 418 patients on preoperativesinus rhythm were operated for ischemic heart disease and associated complications (left ventricleaneurysm repair and ischemic mitral insufficiency in a single center, by a single surgeon.The preoperative, intraoperative and postoperative variables were studied.Results: The mean age of the patients were 61.92 ± 10.05, and 77.5% were male. Atrial fibrillationdeveloped in 68 (16.3% patients. The incidence peaked at second day. Patients with atrialfibrillation were older (p< 0.001. Gender, preoperative comorbidities, ejection fraction, left atrialdiameter, preoperative beta-blocker use, leukocyte count, type of operation and intraoperativevariables did not affect its occurence. Intensive care unit and hospital length of stay were longer(p< 0.05. 95.5% (n= 65 of patients were in normal sinus rhythm at discharge.Conclusion: Postoperative atrial fibrillation is a popular subject with unknowns and controversialresults which may lead to wrong interpretations. We believe that every center has its own risk factors related with the population of that region. Discussion will last, but simple precautions and close monitoring will help to minimizeadverse outcomes.

[Total artificial heart].

Science.gov (United States)

Antretter, H; Dumfarth, J; Höfer, D

2015-09-01

To date the CardioWest™ total artificial heart is the only clinically available implantable biventricular mechanical replacement for irreversible cardiac failure. This article presents the indications, contraindications, implantation procedere and postoperative treatment. In addition to a overview of the applications of the total artificial heart this article gives a brief presentation of the two patients treated in our department with the CardioWest™. The clinical course, postoperative rehabilitation, device-related complications and control mechanisms are presented. The total artificial heart is a reliable implant for treating critically ill patients with irreversible cardiogenic shock. A bridge to transplantation is feasible with excellent results.

[Instrumental, directive, and affective communication in hospital leaflets].

Science.gov (United States)

Vasconcellos-Silva, Paulo Roberto; Uribe Rivera, Francisco Javier; Castiel, Luis David

2003-01-01

This study focuses on the typical semantic systems extracted from hospital staff communicative resources which attempt to validate information as an "object" to be transferred to patients. We describe the models of textual communication in 58 patient information leaflets from five hospital units in Brazil, gathered from 1996 to 2002. Three categories were identified, based on the theory of speech acts (Austin, Searle, and Habermas): 1) cognitive-instrumental utterances: descriptions by means of technical terms validated by self-referred, incomplete, or inaccessible argumentation, with an implicit educational function; 2) technical-directive utterances: self-referred (to the context of the source domains), with a shifting of everyday acts to a technical terrain with a disciplinary function and impersonal features; and 3) expressive modulations: need for inter-subjective connections to strengthen bonds of trust and a tendency to use childish arguments. We conclude that the three categories displayed: fragmentary sources; assumption of univocal messages and invariable use of information (idealized motivations and interests, apart from individualized perspectives); and assumption of universal interests as generators of knowledge.

Catheter Ablation of Atrial Fibrillation in Patients with Hardware in the Heart - Septal Closure Devices, Mechanical Valves and More.

Science.gov (United States)

Bartoletti, Stefano; Santangeli, Pasquale; DI Biase, Luigi; Natale, Andrea

2013-01-01

Patients with mechanical "hardware" in the heart, such as those with mechanical cardiac valves or atrial septal closure devices, represent a population at high risk of developing AF. Catheter ablation of AF in these subjects might represent a challenge, due to the perceived higher risk of complications associated with the presence of intracardiac mechanical devices. Accordingly, such patients were excluded or poorly represented in major trials proving the benefit of catheter ablation for the rhythm-control of AF. However, recent evidence supports the concept that catheter ablation procedures might be equally effective in these patients, without a significant increase in the risk of procedural complications. This review will summarize the current state-of-the-art on catheter ablation of AF in patients with mechanical "hardware" in the heart.

Cone beam tomography of the heart using single-photon emission-computed tomography

International Nuclear Information System (INIS)

Gullberg, G.T.; Christian, P.E.; Zeng, G.L.; Datz, F.L.; Morgan, H.T.

1991-01-01

The authors evaluated cone beam single-photon emission-computed tomography (SPECT) of the heart. A new cone beam reconstruction algorithm was used to reconstruct data collected from short scan acquisitions (of slightly more than 180 degrees) of a detector anteriorally traversing a noncircular orbit. The less than 360 degrees acquisition was used to minimize the attenuation artifacts that result from reconstructing posterior projections of 201T1 emissions from the heart. The algorithm includes a new method for reconstructing truncated projections of background tissue activity that eliminates reconstruction ring artifacts. Phantom and patient results are presented which compare a high-resolution cone beam collimator (50-cm focal length; 6.0-mm full width at half maximum [FWHM] at 10 cm) to a low-energy general purpose (LEGP) parallel hole collimator (8.2-mm FWHM at 10 cm) which is 1.33 times more sensitive. The cone beam tomographic results are free of reconstruction artifacts and show improved spatial and contrast resolution over that obtained with the LEGP parallel hole collimator. The limited angular sampling restrictions and truncation problems associated with cone beam tomography do not deter from obtaining diagnostic information. However, even though these preliminary results are encouraging, a thorough clinical study is still needed to investigate the specificity and sensitivity of cone beam tomography

Congenital heart defects in newborns with apparently isolated single gastrointestinal malformation: A retrospective study.

Science.gov (United States)

Schierz, Ingrid Anne Mandy; Pinello, Giuseppa; Giuffrè, Mario; La Placa, Simona; Piro, Ettore; Corsello, Giovanni

2016-12-01

Congenital gastrointestinal system malformations/abdominal wall defects (GISM) may appear as isolated defects (single or complex), or in association with multiple malformations. The high incidence of association of GISM and congenital heart defects (CHD) in patients with syndromes and malformative sequences is known, but less expected is the association of apparently isolated single GISM and CHD. The aim of this study was to investigate the frequency of CHD in newborns with isolated GISM, and the possibility to modify the diagnostic-therapeutic approach just before the onset of cardiac symptoms or complications. Anamnestic, clinical, and imaging data of newborns requiring abdominal surgery for GISM, between 2009 and 2014, were compared with a control group of healthy newborns. Distribution of GISM and cardiovascular abnormalities were analyzed, and risk factors for adverse outcomes were identified. Seventy-one newborns with isolated GISM were included in this study. More frequent GISM were intestinal rotation and fixation disorders. CHD were observed in 15.5% of patients, augmenting their risk for morbidity. Risk factors for morbidity related to sepsis were identified in central venous catheter, intestinal stoma, and H2-inhibitor-drugs. Moreover, 28.2% of newborns presented only functional cardiac disorders but an unexpectedly higher mortality. The high incidence of congenital heart disease in infants with apparently isolated GISM confirms the need to perform an echocardiographic study before surgery to improve perioperative management and prevent complications such as sepsis and endocarditis. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Evaluation of regional pulmonary blood flow in mitral valvular heart disease using single-pass radionuclide angiocardiography

International Nuclear Information System (INIS)

Chang-Soon Koh; Byung Tae Kim; Myung Chul Lee; Bo Yeon Cho

1982-01-01

Pulmonary hypertension in mitral valvular cardiac disease has been evaluated in 122 patients by a modified upper lung/lower count ratio using single-pass radionuclide angiocardiography. The mean upper lung/lower lung radio correlates well with pulmonary artery mean (r=0.483) and wedge pressure (r=0.804). After correction surgery of the cardiac valve, the ratio decreases and returns to normal range in patients judged clinically to have good surgical benifit. This modified method using single-pass technique provides additional simple, reproducible and nontraumatic results of regional pulmonary blood flow and appears to be correlated with the degree of pulmonary hypertension in mitral heart disease

Mechanics of biopolymer materials: Single chains to bulk properties

NARCIS (Netherlands)

Amuasi, H.E.; Storm, C.

2010-01-01

We outline the first stages in the multiscale modeling of biopolymer materials, starting with the statistical mechanics of single stiff chains. In the first coarse graining step, we demonstrate how to integrate out the single polymer degrees of freedom in supramolecular assemblies of such

Assessment of Cardiovascular Apoptosis in the Isolated Rat Heart by Magnetic Resonance Molecular Imaging

Directory of Open Access Journals (Sweden)

Karl-Heinz Hiller

2006-04-01

Full Text Available Apoptosis, an active process of cell self-destruction, is associated with myocardial ischemia. The redistribution of phosphatidylserine (PS from the inner to the outer leaflet of the cell membrane is an early event in apoptosis. Annexin V, a protein with high specificity and tight binding to PS, was used to identify and localize apoptosis in the ischemic heart. Fluorescein-labeled annexin V has been used routinely for the assessment of apoptosis in vitro. For the detection of apoptosis in vivo, positron emission tomography and single-photon emission computed tomography have been shown to be suitable tools. In view of the relatively low spatial resolution of nuclear imaging techniques, we developed a high-resolution contrast-enhanced magnetic resonance imaging (MRI method that allows rapid and noninvasive monitoring of apoptosis in intact organs. Instead of employing superparamagnetic iron oxide particles linked to annexin V, a new T1 contrast agent was used. To this effect, annexin V was linked to gadolinium diethylenetriamine pentaacetate (Gd-DTPA-coated liposomes. The left coronary artery of perfused isolated rat hearts was ligated for 30 min followed by reperfusion. T1 and T2* images were acquired by using an 11.7-T magnet before and after intracoronary injection of Gd-DTP-labeled annexin V to visualize apoptotic cells. A significant increase in signal intensity was visible in those regions containing cardiomyocytes in the early stage of apoptosis. Because labeling of early apoptotic cell death in intact organs by histological and immunohistochemical methods remains challenging, the use of Gd-DTPA-labeled annexin V in MRI is clearly an improvement in rapid targeting of apoptotic cells in the ischemic and reperfused myocardium.

Histone methylations in heart development, congenital and adult heart diseases.

Science.gov (United States)

Zhang, Qing-Jun; Liu, Zhi-Ping

2015-01-01

Heart development comprises myocyte specification, differentiation and cardiac morphogenesis. These processes are regulated by a group of core cardiac transcription factors in a coordinated temporal and spatial manner. Histone methylation is an emerging epigenetic mechanism for regulating gene transcription. Interplay among cardiac transcription factors and histone lysine modifiers plays important role in heart development. Aberrant expression and mutation of the histone lysine modifiers during development and in adult life can cause either embryonic lethality or congenital heart diseases, and influences the response of adult hearts to pathological stresses. In this review, we describe current body of literature on the role of several common histone methylations and their modifying enzymes in heart development, congenital and adult heart diseases.

The Optimal Timing of Stage 2 Palliation for Hypoplastic Left Heart Syndrome: An Analysis of the Pediatric Heart Network Single Ventricle Reconstruction Trial Public Data Set.

Science.gov (United States)

Meza, James M; Hickey, Edward J; Blackstone, Eugene H; Jaquiss, Robert D B; Anderson, Brett R; Williams, William G; Cai, Sally; Van Arsdell, Glen S; Karamlou, Tara; McCrindle, Brian W

2017-10-31

In infants requiring 3-stage single-ventricle palliation for hypoplastic left heart syndrome, attrition after the Norwood procedure remains significant. The effect of the timing of stage 2 palliation (S2P), a physician-modifiable factor, on long-term survival is not well understood. We hypothesized that an optimal interval between the Norwood and S2P that both minimizes pre-S2P attrition and maximizes post-S2P survival exists and is associated with individual patient characteristics. The National Institutes of Health/National Heart, Lung, and Blood Institute Pediatric Heart Network Single Ventricle Reconstruction Trial public data set was used. Transplant-free survival (TFS) was modeled from (1) Norwood to S2P and (2) S2P to 3 years by using parametric hazard analysis. Factors associated with death or heart transplantation were determined for each interval. To account for staged procedures, risk-adjusted, 3-year, post-Norwood TFS (the probability of TFS at 3 years given survival to S2P) was calculated using parametric conditional survival analysis. TFS from the Norwood to S2P was first predicted. TFS after S2P to 3 years was then predicted and adjusted for attrition before S2P by multiplying by the estimate of TFS to S2P. The optimal timing of S2P was determined by generating nomograms of risk-adjusted, 3-year, post-Norwood, TFS versus the interval from the Norwood to S2P. Of 547 included patients, 399 survived to S2P (73%). Of the survivors to S2P, 349 (87%) survived to 3-year follow-up. The median interval from the Norwood to S2P was 5.1 (interquartile range, 4.1-6.0) months. The risk-adjusted, 3-year, TFS was 68±7%. A Norwood-S2P interval of 3 to 6 months was associated with greatest 3-year TFS overall and in patients with few risk factors. In patients with multiple risk factors, TFS was severely compromised, regardless of the timing of S2P and most severely when S2P was performed early. No difference in the optimal timing of S2P existed when stratified by

Cardiac Rotational Mechanics As a Predictor of Myocardial Recovery in Heart Failure Patients Undergoing Chronic Mechanical Circulatory Support: A Pilot Study.

Science.gov (United States)

Bonios, Michael J; Koliopoulou, Antigone; Wever-Pinzon, Omar; Taleb, Iosif; Stehlik, Josef; Xu, Weining; Wever-Pinzon, James; Catino, Anna; Kfoury, Abdallah G; Horne, Benjamin D; Nativi-Nicolau, Jose; Adamopoulos, Stamatis N; Fang, James C; Selzman, Craig H; Bax, Jeroen J; Drakos, Stavros G

2018-04-01

Impaired qualitative and quantitative left ventricular (LV) rotational mechanics predict cardiac remodeling progression and prognosis after myocardial infarction. We investigated whether cardiac rotational mechanics can predict cardiac recovery in chronic advanced cardiomyopathy patients. Sixty-three patients with advanced and chronic dilated cardiomyopathy undergoing implantation of LV assist device (LVAD) were prospectively investigated using speckle tracking echocardiography. Acute heart failure patients were prospectively excluded. We evaluated LV rotational mechanics (apical and basal LV twist, LV torsion) and deformational mechanics (circumferential and longitudinal strain) before LVAD implantation. Cardiac recovery post-LVAD implantation was defined as (1) final resulting LV ejection fraction ≥40%, (2) relative LV ejection fraction increase ≥50%, (iii) relative LV end-systolic volume decrease ≥50% (all 3 required). Twelve patients fulfilled the criteria for cardiac recovery (Rec Group). The Rec Group had significantly less impaired pre-LVAD peak LV torsion compared with the Non-Rec Group. Notably, both groups had similarly reduced pre-LVAD LV ejection fraction. By receiver operating characteristic curve analysis, pre-LVAD peak LV torsion of 0.35 degrees/cm had a 92% sensitivity and a 73% specificity in predicting cardiac recovery. Peak LV torsion before LVAD implantation was found to be an independent predictor of cardiac recovery after LVAD implantation (odds ratio, 0.65 per 0.1 degrees/cm [0.49-0.87]; P =0.014). LV rotational mechanics seem to be useful in selecting patients prone to cardiac recovery after mechanical unloading induced by LVADs. Future studies should investigate the utility of these markers in predicting durable cardiac recovery after the explantation of the cardiac assist device. © 2018 American Heart Association, Inc.

Phonon number measurements using single photon opto-mechanics

International Nuclear Information System (INIS)

Basiri-Esfahani, S; Akram, U; Milburn, G J

2012-01-01

We describe a system composed of two coupled optical cavity modes with a coupling modulated by a bulk mechanical resonator. In addition, one of the cavity modes is irreversibly coupled to a single photon source. Our scheme is an opto-mechanical realization of the Jaynes–Cummings model where the qubit is a dual rail optical qubit while the bosonic degree of freedom is a matter degree of freedom realized as the bulk mechanical excitation. We show the possibility of engineering phonon number states of the mechanical oscillator in such a system by computing the conditional state of the mechanics after successive photon counting measurements. (paper)

Interagency registry for mechanically assisted circulatory support report on the total artificial heart.

Science.gov (United States)

Arabía, Francisco A; Cantor, Ryan S; Koehl, Devin A; Kasirajan, Vigneshwar; Gregoric, Igor; Moriguchi, Jaime D; Esmailian, Fardad; Ramzy, Danny; Chung, Joshua S; Czer, Lawrence S; Kobashigawa, Jon A; Smith, Richard G; Kirklin, James K

2018-04-26

We sought to better understand the patient population who receive a temporary total artificial heart (TAH) as bridge to transplant or as bridge to decision by evaluating data from the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) database. We examined data related to survival, adverse events, and competing outcomes from patients who received TAHs between June 2006 and April 2017 and used hazard function analysis to explore risk factors for mortality. Data from 450 patients (87% men; mean age, 50 years) were available in the INTERMACS database. The 2 most common diagnoses were dilated cardiomyopathy (50%) and ischemic cardiomyopathy (20%). Risk factors for right heart failure were present in 82% of patients. Most patients were INTERMACS Profile 1 (43%) or 2 (37%) at implantation. There were 266 patients who eventually underwent transplantation, and 162 died. Overall 3-, 6-, and 12-month actuarial survival rates were 73%, 62%, and 53%, respectively. Risk factors for death included older age (p = 0.001), need for pre-implantation dialysis (p = 0.006), higher creatinine (p = 0.008) and lower albumin (p Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

Ergosterol is mainly located in the cytoplasmic leaflet of the yeast plasma membrane.

Science.gov (United States)

Solanko, Lukasz M; Sullivan, David P; Sere, Yves Y; Szomek, Maria; Lunding, Anita; Solanko, Katarzyna A; Pizovic, Azra; Stanchev, Lyubomir D; Pomorski, Thomas Günther; Menon, Anant K; Wüstner, Daniel

2018-03-01

Transbilayer lipid asymmetry is a fundamental characteristic of the eukaryotic cell plasma membrane (PM). While PM phospholipid asymmetry is well documented, the transbilayer distribution of PM sterols such as mammalian cholesterol and yeast ergosterol is not reliably known. We now report that sterols are asymmetrically distributed across the yeast PM, with the majority (~80%) located in the cytoplasmic leaflet. By exploiting the sterol-auxotrophic hem1Δ yeast strain we obtained cells in which endogenous ergosterol was quantitatively replaced with dehydroergosterol (DHE), a closely related fluorescent sterol that functionally and accurately substitutes for ergosterol in vivo. Using fluorescence spectrophotometry and microscopy we found that membrane-impermeant collisional quenchers (spin-labeled phosphatidylcholine and trinitrobenzene sulfonic acid). Efficient quenching was seen only after the cells were disrupted by glass-bead lysis or repeated freeze-thaw to allow quenchers access to the cell interior. The extent of quenching was unaffected by treatments that deplete cellular ATP levels, collapse the PM electrochemical gradient or affect the actin cytoskeleton. However, alterations in PM phospholipid asymmetry in cells lacking phospholipid flippases resulted in a more symmetric transbilayer distribution of sterol. Similarly, an increase in the quenchable pool of DHE was observed when PM sphingolipid levels were reduced by treating cells with myriocin. We deduce that sterols comprise up to ~45% of all inner leaflet lipids in the PM, a result that necessitates revision of current models of the architecture of the PM lipid bilayer. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Airway Complications of Total Artificial Heart.

Science.gov (United States)

Pathak, Vikas; Donovan, Colin; Malhotra, Rajiv

2017-02-01

The total artificial heart is the mechanical device which is used as a bridge to the heart transplant in patients with biventricular failure. Due to the mechanical nature of the device, patients receiving total artificial heart (TAH) require to be on anticoagulation therapy. Hemorrhage and coagulopathy are few of the known complications of TAH.

Fast Simulation of Mechanical Heterogeneity in the Electrically Asynchronous Heart Using the MultiPatch Module.

Directory of Open Access Journals (Sweden)

John Walmsley

2015-07-01

Full Text Available Cardiac electrical asynchrony occurs as a result of cardiac pacing or conduction disorders such as left bundle-branch block (LBBB. Electrically asynchronous activation causes myocardial contraction heterogeneity that can be detrimental for cardiac function. Computational models provide a tool for understanding pathological consequences of dyssynchronous contraction. Simulations of mechanical dyssynchrony within the heart are typically performed using the finite element method, whose computational intensity may present an obstacle to clinical deployment of patient-specific models. We present an alternative based on the CircAdapt lumped-parameter model of the heart and circulatory system, called the MultiPatch module. Cardiac walls are subdivided into an arbitrary number of patches of homogeneous tissue. Tissue properties and activation time can differ between patches. All patches within a wall share a common wall tension and curvature. Consequently, spatial location within the wall is not required to calculate deformation in a patch. We test the hypothesis that activation time is more important than tissue location for determining mechanical deformation in asynchronous hearts. We perform simulations representing an experimental study of myocardial deformation induced by ventricular pacing, and a patient with LBBB and heart failure using endocardial recordings of electrical activation, wall volumes, and end-diastolic volumes. Direct comparison between simulated and experimental strain patterns shows both qualitative and quantitative agreement between model fibre strain and experimental circumferential strain in terms of shortening and rebound stretch during ejection. Local myofibre strain in the patient simulation shows qualitative agreement with circumferential strain patterns observed in the patient using tagged MRI. We conclude that the MultiPatch module produces realistic regional deformation patterns in the asynchronous heart and that

Single-ion nonlinear mechanical oscillator

International Nuclear Information System (INIS)

Akerman, N.; Kotler, S.; Glickman, Y.; Dallal, Y.; Keselman, A.; Ozeri, R.

2010-01-01

We study the steady-state motion of a single trapped ion oscillator driven to the nonlinear regime. Damping is achieved via Doppler laser cooling. The ion motion is found to be well described by the Duffing oscillator model with an additional nonlinear damping term. We demonstrate here the unique ability of tuning both the linear as well as the nonlinear damping coefficients by controlling the laser-cooling parameters. Our observations pave the way for the investigation of nonlinear dynamics on the quantum-to-classical interface as well as mechanical noise squeezing in laser-cooling dynamics.

Heart transplantation for adults with congenital heart disease: current status and future prospects.

Science.gov (United States)

Matsuda, Hikaru; Ichikawa, Hajime; Ueno, Takayoshi; Sawa, Yoshiki

2017-06-01

Increased survival rates after corrective or palliative surgery for complex congenital heart disease (CHD) in infancy and childhood are now being coupled with increased numbers of patients who survive to adulthood with various residual lesions or sequelae. These patients are likely to deteriorate in cardiac function or end-organ function, eventually requiring lifesaving treatment including heart transplantation. Although early and late outcomes of heart transplantation have been improving for adult survivors of CHD, outcomes and pretransplant management could still be improved. Survivors of Fontan procedures are a vulnerable cohort, particularly when single ventricle physiology fails, mostly with protein-losing enteropathy and hepatic dysfunction. Therefore, we reviewed single-institution and larger database analyses of adults who underwent heart transplantation for CHD, to enable risk stratification by identifying the indications and outcomes. As the results, despite relatively high early mortality, long-term results were encouraging after heart transplantation. However, further investigations are needed to improve the indication criteria for complex CHD, especially for failed Fontan. In addition, the current system of status criteria and donor heart allocation system in heart transplantation should be arranged as suitable for adults with complex CHD. Furthermore, there is a strong need to develop ventricular assist devices as a bridge to transplantation or destination therapy, especially where right-sided circulatory support is needed.

TIPSS Procedure in the Treatment of a Single Patient After Recent Heart Transplantation Because of Refractory Ascites Due to Cardiac Cirrhosis

International Nuclear Information System (INIS)

Fava, Mario; Meneses, Luis; Loyola, Soledad; Castro, Pablo; Barahona, Fernando

2008-01-01

We present the case of a female patient with arrhythmogenic dysplasia of the right ventricle who evolved to refractory heart failure, ascites, and peripheral edema. As a result, heart transplantation was performed. Subsequently, refractory ascites impaired the patient's respiratory function, resulting in prolonged mechanical ventilation. She was successfully treated with transjugular intrahepatic portosystemic shunt (TIPSS) placement, which allowed satisfactory weaning of ventilatory support.

CD133 antibody conjugation to decellularized human heart valves intended for circulating cell capture.

Science.gov (United States)

Vossler, John D; Min Ju, Young; Williams, J Koudy; Goldstein, Steven; Hamlin, James; Lee, Sang Jin; Yoo, James J; Atala, Anthony

2015-09-03

The long term efficacy of tissue based heart valve grafts may be limited by progressive degeneration characterized by immune mediated inflammation and calcification. To avoid this degeneration, decellularized heart valves with functionalized surfaces capable of rapid in vivo endothelialization have been developed. The aim of this study is to examine the capacity of CD133 antibody-conjugated valve tissue to capture circulating endothelial progenitor cells (EPCs). Decellularized human pulmonary valve tissue was conjugated with CD133 antibody at varying concentrations and exposed to CD133 expressing NTERA-2 cl.D1 (NT2) cells in a microflow chamber. The amount of CD133 antibody conjugated on the valve tissue surface and the number of NT2 cells captured in the presence of shear stress was measured. Both the amount of CD133 antibody conjugated to the valve leaflet surface and the number of adherent NT2 cells increased as the concentration of CD133 antibody present in the surface immobilization procedure increased. The data presented in this study support the hypothesis that the rate of CD133(+) cell adhesion in the presence of shear stress to decellularized heart valve tissue functionalized by CD133 antibody conjugation increases as the quantity of CD133 antibody conjugated to the tissue surface increases.

Chronic heart failure modifies respiratory mechanics in rats: a randomized controlled trial

Directory of Open Access Journals (Sweden)

Deise M. Pacheco

2016-01-01

Full Text Available ABSTRACT Objective To analyze respiratory mechanics and hemodynamic alterations in an experimental model of chronic heart failure (CHF following myocardial infarction. Method Twenty-seven male adult Wistar rats were randomized to CHF group (n=12 or Sham group (n=15. Ten weeks after coronary ligation or sham surgery, the animals were anesthetized and submitted to respiratory mechanics and hemodynamic measurements. Pulmonary edema as well as cardiac remodeling were measured. Results The CHF rats showed pulmonary edema 26% higher than the Sham group. The respiratory system compliance (Crs and the total lung capacity (TLC were lower (40% and 27%, respectively in the CHF rats when compared to the Sham group (P<0.01. There was also an increase in tissue resistance (Gti and elastance (Hti (28% and 45%, respectively in the CHF group. Moreover, left ventricular end-diastolic pressure was higher (32 mmHg vs 4 mmHg, P<0.01, while the left ventricular systolic pressure was lower (118 mmHg vs 130 mmHg, P=0.02 in the CHF group when compared to the control. Pearson’s correlation coefficient showed a negative association between pulmonary edema and Crs (r=–0.70, P=0.0001 and between pulmonary edema and TLC (r=–0.67,P=0.0034. Pulmonary edema correlated positively with Gti (r=0.68, P=0.001 and Hti (r=0.68, P=0.001. Finally, there was a strong positive relationship between pulmonary edema and heart weight (r=0.80, P=0.001. Conclusion Rats with CHF present important changes in hemodynamic and respiratory mechanics, which may be associated with alterations in cardiopulmonary interactions.

High-mechanical-strength single-pulse draw tower gratings

Science.gov (United States)

Rothhardt, Manfred W.; Chojetzki, Christoph; Mueller, Hans Rainer

2004-11-01

The inscription of fiber Bragg gratings during the drawing process is a very useful method to realize sensor arrays with high numbers of gratings and excellent mechanical strength and also type II gratings with high temperature stability. Results of single pulse grating arrays with numbers up to 100 and definite wavelengths and positions for sensor applications were achieved at 1550 nm and 830 nm using new photosensitive fibers developed in IPHT. Single pulse type I gratings at 1550 nm with more than 30% reflectivity were shown first time to our knowledge. The mechanical strength of this fiber with an Ormocer coating with those single pulse gratings is the same like standard telecom fibers. Weibull plots of fiber tests will be shown. At 830 nm we reached more than 10% reflectivity with single pulse writing during the fiber drawing in photosensitive fibers with less than 16 dB/km transmission loss. These gratings are useful for stress and vibration sensing applications. Type II gratings with reflectivity near 100% and smooth spectral shape and spectral width of about 1 nm are temperature stable up to 1200 K for short time. They are also realized in the fiber drawing process. These gratings are useful for temperature sensor applications.

Mechanical perturbation control of cardiac alternans

Science.gov (United States)

Hazim, Azzam; Belhamadia, Youssef; Dubljevic, Stevan

2018-05-01

Cardiac alternans is a disturbance in heart rhythm that is linked to the onset of lethal cardiac arrhythmias. Mechanical perturbation control has been recently used to suppress alternans in cardiac tissue of relevant size. In this control strategy, cardiac tissue mechanics are perturbed via active tension generated by the heart's electrical activity, which alters the tissue's electric wave profile through mechanoelectric coupling. We analyze the effects of mechanical perturbation on the dynamics of a map model that couples the membrane voltage and active tension systems at the cellular level. Therefore, a two-dimensional iterative map of the heart beat-to-beat dynamics is introduced, and a stability analysis of the system of coupled maps is performed in the presence of a mechanical perturbation algorithm. To this end, a bidirectional coupling between the membrane voltage and active tension systems in a single cardiac cell is provided, and a discrete form of the proposed control algorithm, that can be incorporated in the coupled maps, is derived. In addition, a realistic electromechanical model of cardiac tissue is employed to explore the feasibility of suppressing alternans at cellular and tissue levels. Electrical activity is represented in two detailed ionic models, the Luo-Rudy 1 and the Fox models, while two active contractile tension models, namely a smooth variant of the Nash-Panfilov model and the Niederer-Hunter-Smith model, are used to represent mechanical activity in the heart. The Mooney-Rivlin passive elasticity model is employed to describe passive mechanical behavior of the myocardium.

Single-institution effectiveness assessment of open-heart surgery in octogenarians

NARCIS (Netherlands)

de Mol, B. A.; Kallewaard, M.; Lewin, F.; van Gaalen, G. L.; van den Brink, R. B.

1997-01-01

To determine short- and long-term outcome of open-heart surgery in octogenarians. We reviewed the medical charts of 130 consecutive octogenarians undergoing open-heart surgery. Patients with significant comorbidity were excluded from the study. The effect of cardiac and operative risk factors on

Deep RNA sequencing reveals dynamic regulation of myocardial noncoding RNAs in failing human heart and remodeling with mechanical circulatory support.

Science.gov (United States)

Yang, Kai-Chien; Yamada, Kathryn A; Patel, Akshar Y; Topkara, Veli K; George, Isaac; Cheema, Faisal H; Ewald, Gregory A; Mann, Douglas L; Nerbonne, Jeanne M

2014-03-04

Microarrays have been used extensively to profile transcriptome remodeling in failing human heart, although the genomic coverage provided is limited and fails to provide a detailed picture of the myocardial transcriptome landscape. Here, we describe sequencing-based transcriptome profiling, providing comprehensive analysis of myocardial mRNA, microRNA (miRNA), and long noncoding RNA (lncRNA) expression in failing human heart before and after mechanical support with a left ventricular (LV) assist device (LVAD). Deep sequencing of RNA isolated from paired nonischemic (NICM; n=8) and ischemic (ICM; n=8) human failing LV samples collected before and after LVAD and from nonfailing human LV (n=8) was conducted. These analyses revealed high abundance of mRNA (37%) and lncRNA (71%) of mitochondrial origin. miRNASeq revealed 160 and 147 differentially expressed miRNAs in ICM and NICM, respectively, compared with nonfailing LV. Among these, only 2 (ICM) and 5 (NICM) miRNAs are normalized with LVAD. RNASeq detected 18 480, including 113 novel, lncRNAs in human LV. Among the 679 (ICM) and 570 (NICM) lncRNAs differentially expressed with heart failure, ≈10% are improved or normalized with LVAD. In addition, the expression signature of lncRNAs, but not miRNAs or mRNAs, distinguishes ICM from NICM. Further analysis suggests that cis-gene regulation represents a major mechanism of action of human cardiac lncRNAs. The myocardial transcriptome is dynamically regulated in advanced heart failure and after LVAD support. The expression profiles of lncRNAs, but not mRNAs or miRNAs, can discriminate failing hearts of different pathologies and are markedly altered in response to LVAD support. These results suggest an important role for lncRNAs in the pathogenesis of heart failure and in reverse remodeling observed with mechanical support.

Aggressiveness of Phytophthora infestans on detached potato leaflets in four Nordic countries

DEFF Research Database (Denmark)

Lehtinen, A; Andersson, B; Le, V H

2009-01-01

differences between the test laboratories for infection efficiency, lesion growth rate and sporulation capacity on detached leaflets. When the laboratory effect was taken into account, the differences in aggressiveness between the countries were generally small or inconsistent between the test cultivars...... and epidemiologically insignificant. By contrast, variation among isolates within countries was substantial. The magnitude of the variation depended on country and cultivar. Maximal variation for the means of the isolates was between 89 and 185 h for latent period, between 100 and 1297 sporangia mm-2 for sporulation...

Activation and Inhibition of Sodium-Hydrogen Exchanger Is a Mechanism That Links the Pathophysiology and Treatment of Diabetes Mellitus With That of Heart Failure.

Science.gov (United States)

Packer, Milton

2017-10-17

The mechanisms underlying the progression of diabetes mellitus and heart failure are closely intertwined, such that worsening of one condition is frequently accompanied by worsening of the other; the degree of clinical acceleration is marked when the 2 coexist. Activation of the sodium-hydrogen exchanger in the heart and vasculature (NHE1 isoform) and the kidneys (NHE3 isoform) may serve as a common mechanism that links both disorders and may underlie their interplay. Insulin insensitivity and adipokine abnormalities (the hallmarks of type 2 diabetes mellitus) are characteristic features of heart failure; conversely, neurohormonal systems activated in heart failure (norepinephrine, angiotensin II, aldosterone, and neprilysin) impair insulin sensitivity and contribute to microvascular disease in diabetes mellitus. Each of these neurohormonal derangements may act through increased activity of both NHE1 and NHE3. Drugs used to treat diabetes mellitus may favorably affect the pathophysiological mechanisms of heart failure by inhibiting either or both NHE isoforms, and drugs used to treat heart failure may have beneficial effects on glucose tolerance and the complications of diabetes mellitus by interfering with the actions of NHE1 and NHE3. The efficacy of NHE inhibitors on the risk of cardiovascular events may be enhanced when heart failure and glucose intolerance coexist and may be attenuated when drugs with NHE inhibitory actions are given concomitantly. Therefore, the sodium-hydrogen exchanger may play a central role in the interplay of diabetes mellitus and heart failure, contribute to the physiological and clinical progression of both diseases, and explain certain drug-drug and drug-disease interactions that have been reported in large-scale randomized clinical trials. © 2017 American Heart Association, Inc.

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.

Mechanical dispersion is associated with poor outcome in heart failure with a severely depressed left ventricular function and bundle branch blocks.

Science.gov (United States)

Stankovic, Ivan; Janicijevic, Aleksandra; Dimic, Aleksandra; Stefanovic, Milica; Vidakovic, Radosav; Putnikovic, Biljana; Neskovic, Aleksandar N

2018-03-01

Bundle branch blocks (BBB)-related mechanical dyssynchrony and dispersion may improve patient selection for device therapy, but their effect on the natural history of this patient population is unknown. A total of 155 patients with LVEF ≤ 35% and BBB, not treated with device therapy, were included. Mechanical dyssynchrony was defined as the presence of either septal flash or apical rocking. Contraction duration was assessed as time interval from the electrocardiographic R-(Q-)wave to peak longitudinal strain in each of 17 left ventricular segments. Mechanical dispersion was defined as either the standard deviation of all time intervals (dispersion SD ) or as the difference between the longest and shortest time intervals (dispersion delta ). Patients were followed for cardiac mortality during a median period of 33 months. Mechanical dyssynchrony was not associated with survival. More pronounced mechanical dispersion delta was found in patients with dyssynchrony than in those without. In the multivariate regression analysis, patients' functional class, diabetes mellitus and dispersion delta were independently associated with mortality. Mechanical dispersion, but not dyssynchrony, was independently associated with mortality and it may be useful for risk stratification of patients with heart failure (HF) and BBB. Key Messages Mechanical dispersion, measured by strain echocardiography, is associated with poor outcome in heart failure with a severely depressed left ventricular function and bundle branch blocks. Mechanical dispersion may be useful for risk stratification of patients with heart failure and bundle branch blocks.

Thyroid and the Heart

Directory of Open Access Journals (Sweden)

A Karas

2009-09-01

Full Text Available The cardiovascular signs and symptoms of thyroid disease are some of the most clinically relevant findings that accompany both hyperthyroidism and hypothyroidism. On the basis of the understanding of the mechanisms of thyroid hormone action on the heart and cardiovascular system, it is possible to explain the changes in cardiac output, cardiac contractility, blood pressure and rhythm disturbances that result from thyroid dysfunction. In the present review will integrate what is known about the mechanisms of thyroid hormone action on the heart and the alterations in thyroid hormone metabolism that accompany chronic congestive heart failure.

Coupling of single quantum emitters to plasmons propagating on mechanically etched wires

DEFF Research Database (Denmark)

Kumar, Shailesh; Huck, Alexander; Lu, Ying-Wei

2013-01-01

We demonstrate the coupling of a single nitrogen vacancy center in a nanodiamond to propagating plasmonic modes of mechanically etched silver nanowires. The mechanical etch is performed on single crystalline silver nanoplates by the tip of an atomic force microscope cantilever to produce wires...

Heart and Cardiovascular Involvement in Patients with Mucopolysaccharidosis Type IVA (Morquio-A Syndrome.

Directory of Open Access Journals (Sweden)

Christoph Kampmann

Full Text Available Mucopolysaccharidosis (MPS IVA is a rare lysosomal storage disorder with multiple skeletal and non-skeletal abnormalities requiring multiple surgical interventions. It is well known that patients with MPS IVA suffer from tachycardia, but cardiac and hemodynamic alterations have not been reported to date. We investigated the cardiovascular and hemodynamic alterations in patients with MPS IVA and developed a possible patho-mechanism for cardiovascular deterioration during anesthesia.In this observational study, serial cardiac examinations were performed in 54 patients with MPS IVA who were followed at the Children's Hospital of the Mainz Medical University (Mainz, Germany between 1991 and 2014 (follow-up 1-24 years; median 5.8 years. Results were compared with data from a large central European cohort of more than 2000 healthy infants and children.None of the patients had arterial hypertension, but 4% had evidence of increased pulmonary artery pressure. Patients developed aortic root extension up to 6.9 standard deviations above normal. Left-sided valve leaflet thickening occurred in 26 patients (five with valve disease. Patients had lower left ventricular dimensions (z: -1.02±0.1, lower stroke volumes (z: -2.3±0.17, lower left ventricular mass (z: -1.5±0.21, but higher wall thickness (z: +0.8±0.16, and higher work index (z: +2.5±0.2 compared to healthy control subjects. Cardiac output was preserved by an increase in heart rate of 21%. Sixty % of patients showed impaired diastolic filling; heart rate (99.0±1.8 vs. 92.0±2.1 bpm, age (18.0±1.8 vs. 14.2±1 years, and cardiothoracic ratio (61.6±3.6% vs. 55±4.2% of these patients were higher compared to those with normal filling.The results of this study suggest an age-progressive disproportion of the intra-thoracic organs of patients with MPS IVA, which is accompanied by aortic root extension and thickened left ventricles, with reduced stroke volumes, impaired diastolic filling patterns, and

Nerves Regulate Cardiomyocyte Proliferation and Heart Regeneration.

Science.gov (United States)

Mahmoud, Ahmed I; O'Meara, Caitlin C; Gemberling, Matthew; Zhao, Long; Bryant, Donald M; Zheng, Ruimao; Gannon, Joseph B; Cai, Lei; Choi, Wen-Yee; Egnaczyk, Gregory F; Burns, Caroline E; Burns, C Geoffrey; MacRae, Calum A; Poss, Kenneth D; Lee, Richard T

2015-08-24

Some organisms, such as adult zebrafish and newborn mice, have the capacity to regenerate heart tissue following injury. Unraveling the mechanisms of heart regeneration is fundamental to understanding why regeneration fails in adult humans. Numerous studies have revealed that nerves are crucial for organ regeneration, thus we aimed to determine whether nerves guide heart regeneration. Here, we show using transgenic zebrafish that inhibition of cardiac innervation leads to reduction of myocyte proliferation following injury. Specifically, pharmacological inhibition of cholinergic nerve function reduces cardiomyocyte proliferation in the injured hearts of both zebrafish and neonatal mice. Direct mechanical denervation impairs heart regeneration in neonatal mice, which was rescued by the administration of neuregulin 1 (NRG1) and nerve growth factor (NGF) recombinant proteins. Transcriptional analysis of mechanically denervated hearts revealed a blunted inflammatory and immune response following injury. These findings demonstrate that nerve function is required for both zebrafish and mouse heart regeneration. Copyright © 2015 Elsevier Inc. All rights reserved.

Metaiodobenzylguanidine [131I] scintigraphy detects impaired myocardial sympathetic neuronal transport function of canine mechanical-overload heart failure

International Nuclear Information System (INIS)

Rabinovitch, M.A.; Rose, C.P.; Rouleau, J.L.

1987-01-01

In heart failure secondary to chronic mechanical overload, cardiac sympathetic neurons demonstrate depressed catecholamine synthetic and transport function. To assess the potential of sympathetic neuronal imaging for detection of depressed transport function, serial scintigrams were acquired after the intravenous administration of metaiodobenzylguanidine [ 131 I] to 13 normal dogs, 3 autotransplanted (denervated) dogs, 5 dogs with left ventricular failure, and 5 dogs with compensated left ventricular hypertrophy due to a surgical arteriovenous shunt. Nine dogs were killed at 14 hours postinjection for determination of metaiodobenzylguanidine [ 131 I] and endogenous norepinephrine content in left atrium, left ventricle, liver, and spleen. By 4 hours postinjection, autotransplanted dogs had a 39% reduction in mean left ventricular tracer accumulation, reflecting an absent intraneuronal tracer pool. Failure dogs demonstrated an accelerated early mean left ventricular tracer efflux rate (26.0%/hour versus 13.7%/hour in normals), reflecting a disproportionately increased extraneuronal tracer pool. They also showed reduced late left ventricular and left atrial concentrations of tracer, consistent with a reduced intraneuronal tracer pool. By contrast, compensated hypertrophy dogs demonstrated a normal early mean left ventricular tracer efflux rate (16.4%/hour) and essentially normal late left ventricular and left atrial concentrations of tracer. Metaiodobenzylguanidine [ 131 I] scintigraphic findings reflect the integrity of the cardiac sympathetic neuronal transport system in canine mechanical-overload heart failure. Metaiodobenzylguanidine [ 123 I] scintigraphy should be explored as a means of early detection of mechanical-overload heart failure in patients

Characterization of a bioprosthetic bicuspid venous valve hemodynamics: implications for mechanism of valve dynamics.

Science.gov (United States)

Tien, W-H; Chen, H Y; Berwick, Z C; Krieger, J; Chambers, S; Dabiri, D; Kassab, G S

2014-10-01

Chronic venous insufficiency (CVI) of the lower extremities is a common clinical problem. Although bioprosthetic valves have been proposed to treat severe reflux, clinical success has been limited due to thrombosis and neointima overgrowth of the leaflets that is, in part, related to the hemodynamics of the valve. A bioprosthetic valve that mimics native valve hemodynamics is essential. A computational model of the prosthetic valve based on realistic geometry and mechanical properties was developed to simulate the interaction of valve structure (fluid-structure interaction, FSI) with the surrounding flow. The simulation results were validated by experiments of a bioprosthetic bicuspid venous valve using particle image velocimetry (PIV) with high spatial and temporal resolution in a pulse duplicator (PD). Flow velocity fields surrounding the valve leaflets were calculated from PIV measurements and comparisons to the FSI simulation results were made. Both the spatial and temporal results of the simulations and experiments were in agreement. The FSI prediction of the transition point from equilibrium phase to valve-closing phase had a 7% delay compared to the PD measurements, while the PIV measurements matched the PD exactly. FSI predictions of reversed flow were within 10% compared to PD measurements. Stagnation or stasis regions were observed in both simulations and experiments. The pressure differential across the valve and associated forces on the leaflets from simulations showed the valve mechanism to be pressure driven. The flow velocity simulations were highly consistent with the experimental results. The FSI simulation and force analysis showed that the valve closure mechanism is pressure driven under the test conditions. FSI simulation and PIV measurements demonstrated that the flow behind the leaflet was mostly stagnant and a potential source for thrombosis. The validated FSI simulations should enable future valve design optimizations that are needed for

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.)

[Consensus on the legibility criteria of health education leaflets].

Science.gov (United States)

Barrio-Cantalejo, I; Simón-Lorda, P; Jiménez, M Melguizo; Ruiz, A Molina

2011-01-01

To identify the most relevant aspects that guarantee the readability, clarity and simplicity of written health education materials. Delphi methodology in order to reach a state of consensus among health education experts on criteria of legibility in the design and publication of informative material and literature. Seventeen experts reached agreement on the principal recommendations for ensuring the legibility of health education materials. They were as follows: a) text content and layout: to structure the text using a title or subtitle, message explanation and conclusion; b) text construction: to use simple and concise sentences, diagrams and examples, and graphically highlighting the principal ideas; c) lexical comprehension: to use simple words and avoid technical language and abbreviations; d) typography: to use an easy-to-read font. There is a high degree of consensus regarding the way health education materials should be drawn up. This list of recommendations could be used as an instrument for reviewing and improving the design of health education materials. In general, it is recommended to identify the users of the leaflets and involve them in the writing and design.

Mechanisms of right heart disease in pulmonary hypertension (2017 Grover Conference Series).

Science.gov (United States)

Asosingh, Kewal; Erzurum, Serpil

2018-01-01

Current dogma is that pathological hypertrophy of the right ventricle is a direct consequence of pulmonary vascular remodeling. However, progression of right ventricle dysfunction is not always lung-dependent. Increased afterload caused by pulmonary vascular remodeling initiates the right ventricle hypertrophy, but determinants leading to adaptive or maladaptive hypertrophy and failure remain unknown. Ischemia in a hypertrophic right ventricle may directly contribute to right heart failure. Rapidly enlarging cardiomyocytes switch from aerobic to anaerobic energy generation resulting in cell growth under relatively hypoxic conditions. Cardiac muscle reacts to an increased afterload by over-activation of the sympathetic system and uncoupling and downregulation of β-adrenergic receptors. Recent studies suggest that β blocker therapy in PH is safe, well tolerated, and preserves right ventricle function and cardiac output by reducing right ventricular glycolysis. Fibrosis, an evolutionary conserved process in host defense and wound healing, is dysregulated in maladaptive cardiac tissue contributing directly to right ventricle failure. Despite several mechanisms having been suggested in right heart disease, the causes of maladaptive cardiac remodeling remain unknown and require further research.

Successful cardiac transplantation outcomes in patients with adult congenital heart disease.

Science.gov (United States)

Menachem, Jonathan N; Golbus, Jessica R; Molina, Maria; Mazurek, Jeremy A; Hornsby, Nicole; Atluri, Pavan; Fuller, Stephanie; Birati, Edo Y; Kim, Yuli Y; Goldberg, Lee R; Wald, Joyce W

2017-09-01

The purpose of our study is (1) to characterise patients with congenital heart disease undergoing heart transplantation by adult cardiac surgeons in a large academic medical centre and (2) to describe successful outcomes associated with our multidisciplinary approach to the evaluation and treatment of adults with congenital heart disease (ACHD) undergoing orthotopic heart transplantation (OHT). Heart failure is the leading cause of death in patients with ACHD leading to increasing referrals for OHT. The Penn Congenital Transplant Database comprises a cohort of patients with ACHD who underwent OHT between March 2010 and April 2016. We performed a retrospective cohort study of the 20 consecutive patients. Original cardiac diagnoses include single ventricle palliated with Fontan (n=8), dextro-transposition of the great arteries after atrial switch (n=4), tetralogy of Fallot (n=4), pulmonary atresia (n=1), Ebstein anomaly (n=1), unrepaired ventricular septal defect (n=1) and Noonan syndrome with coarctation of the aorta (n=1). Eight patients required pretransplant inotropes and two required pretransplant mechanical support. Nine patients underwent heart-liver transplant and three underwent heart-lung transplant. Three patients required postoperative mechanical circulatory support. Patients were followed for an average of 38 months as of April 2016, with 100% survival at 30 days and 1 year and 94% overall survival (19/20 patients). ACHD-OHT patients require highly specialised, complex and multidisciplinary healthcare. The success of our programme is attributed to using team-based, patient-centred care including our multidisciplinary staff and specialists across programmes and departments. © 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.

Education and Coronary Heart Disease Risk: Potential Mechanisms Such as Literacy, Perceived Constraints, and Depressive Symptoms

Science.gov (United States)

Loucks, Eric B.; Gilman, Stephen E.; Howe, Chanelle J.; Kawachi, Ichiro; Kubzansky, Laura D.; Rudd, Rima E.; Martin, Laurie T.; Nandi, Arijit; Wilhelm, Aude; Buka, Stephen L.

2015-01-01

Objective: Education is inversely associated with coronary heart disease (CHD) risk; however the mechanisms are poorly understood. The study objectives were to evaluate the extent to which rarely measured factors (literacy, time preference, sense of control) and more commonly measured factors (income, depressive symptomatology, body mass index) in…

Arterial wall mechanics as a function of heart rate: role of vascular smooth muscle

International Nuclear Information System (INIS)

Salvucci, Fernando Pablo; Schiavone, Jonathan; Craiem, Damian; Barra, Juan Gabriel

2007-01-01

Vascular wall viscoelasticity can be evaluated using a first-order lumped model. This model consists of a spring with elastic constant E and a dashpot with viscous constant η. More importantly, this viscoelastic model can be fitted in-vivo measuring arterial pressure and diameter. The aim of this work is to analyze the influence of heart rate over E and η. In two anesthetized sheep, diameter in thoracic aorta and intravascular pressure has been registered. The right atrium was connected to a programmable stimulator through a pair of pace-maker wires to produce changes in stimulation heart rate (HR) from 80 to 160 bpm. Additionally, local activation of vascular smooth muscle was induced with phenylephrine. After converting pressure and diameter signals into stress and strain respectively, E y η were calculated in control state and during muscle activation. The elastic modulus E did not present significant changes with heart rate. The viscous modulus η decreased 49% with a two-fold acceleration in heart rate from 80 to 160 bpm. However, the product η HR remained stable. The viscous modulus η increased 39% with smooth muscle activation. No significant pressure changes were registered during the experiment. The contractile action of vascular smooth muscle could contribute to increasing arterial wall viscosity. The decrease of η when HR increased might be related to smooth muscle relaxation mediated by endothelium activity, which was stimulated by flow increase. We conclude that HR can modulate arterial wall viscoelasticity through endothelium-dependent mechanisms

Verification of pharmacogenetics-based warfarin dosing algorithms in Han-Chinese patients undertaking mechanic heart valve replacement.

Science.gov (United States)

Zhao, Li; Chen, Chunxia; Li, Bei; Dong, Li; Guo, Yingqiang; Xiao, Xijun; Zhang, Eryong; Qin, Li

2014-01-01

To study the performance of pharmacogenetics-based warfarin dosing algorithms in the initial and the stable warfarin treatment phases in a cohort of Han-Chinese patients undertaking mechanic heart valve replacement. We searched PubMed, Chinese National Knowledge Infrastructure and Wanfang databases for selecting pharmacogenetics-based warfarin dosing models. Patients with mechanic heart valve replacement were consecutively recruited between March 2012 and July 2012. The predicted warfarin dose of each patient was calculated and compared with the observed initial and stable warfarin doses. The percentage of patients whose predicted dose fell within 20% of their actual therapeutic dose (percentage within 20%), and the mean absolute error (MAE) were utilized to evaluate the predictive accuracy of all the selected algorithms. A total of 8 algorithms including Du, Huang, Miao, Wei, Zhang, Lou, Gage, and International Warfarin Pharmacogenetics Consortium (IWPC) model, were tested in 181 patients. The MAE of the Gage, IWPC and 6 Han-Chinese pharmacogenetics-based warfarin dosing algorithms was less than 0.6 mg/day in accuracy and the percentage within 20% exceeded 45% in all of the selected models in both the initial and the stable treatment stages. When patients were stratified according to the warfarin dose range, all of the equations demonstrated better performance in the ideal-dose range (1.88-4.38 mg/day) than the low-dose range (pharmacogenetics-based warfarin dosing regimens performed similarly in our cohort. However, the algorithms of Wei, Huang, and Miao showed a better potential for warfarin prediction in the initial and the stable treatment phases in Han-Chinese patients undertaking mechanic heart valve replacement.

Effect of in vivo heart irradiation on the development of antioxidant defenses and cardiac functions in the rat

International Nuclear Information System (INIS)

Benderitter, M.; Assem, M.; Maupoil, V.

1995-01-01

During radiotherapy of thoracic tumors, the heart is often included in the primary treatment volume, and chronic impairment of myocardial function occurs. The cellular biomolecules are altered directly by radiation or damaged indirectly by free radical production. The purpose of this investigation was to evaluate the biochemical and functional response of the rat heart to a single high dose of radiation. The effect of 20 Gy local X irradiation was determined in the heart of Wistar rats under general anesthesia. Mechanical performances were measured in vitro using an isolated perfused working heart model, and cardiac antioxidant defenses were also evaluated. Hearts were studied at 1 and 4 months after irradiation. This single dose of radiation induced a marked drop in the mechanical activity of the rat heart: aortic output was significantly reduced (18% less than control values) at 1 month postirradiation and remained depressed for the rest of the experimental period (21% less than control 4 months after treatment). This suggests the development of myocardial failure after irradiation. The decline of functional parameters was associated with changes in antioxidant defenses. The decrease in cardiac levels of vitamin E (-30%) was associated with an increase in the levels of Mn-SOD and glustathione peroxidase (+45.5% and +32%, respectively, at 4 months postirradiation). However, cardiac vitamin C and catalase levels remained constant. Since these antioxidant defenses were activated relatively long after irradiation, it is suggested that this was probable due to the production of free radical species associated with the development of inflammation. 49 refs., 8 figs., 1 tab

Charge collection and SEU (Single Event Upset) mechanisms

International Nuclear Information System (INIS)

Musseau, O.

1994-01-01

The purpose of this paper is to review the mechanisms of single event upset in microelectronic devices due to interaction with cosmic ions. Experimental and theoretical results are presented, and actual questions and problems are discussed. A brief introduction recalls the creation of the dense plasma of electron-hole pairs along the ion track. The basic processes for charge collection in a simple np junction (drift and diffusion) are presented. The funneling-field effect is discussed and experimental results are compared to numerical simulations and semi-empirical models. Charge collection in actual microelectronic structures is then presented. Single event upset of memory cells is discussed, based on numerical and experimental data. The main parameters for device characterization are presented. From the physical interpretation of charge collection mechanisms, the intrinsic sensitivity of various microelectronic technologies is determined and compared to experimental data. Scaling laws and future trends are discussed. (author)

Pulmonary artery dissection following balloon valvuloplasty in a dog with pulmonic stenosis.

Science.gov (United States)

Grint, K A; Kellihan, H B

2017-04-01

A 3-month-old, 9.9 kg, male pit bull cross was referred for evaluation of collapse. A left basilar systolic heart murmur graded V/VI and a grade IV/VI right basilar systolic heart murmur were ausculted. Echocardiography showed severe pulmonic stenosis characterized by annular hypoplasia, leaflet thickening, and leaflet fusion. After 1 month of atenolol therapy, a pulmonic valve balloon valvuloplasty procedure was performed, and the intra-operative right ventricular pressure was reduced by 43%. Echocardiography, performed the following day, showed apparent rupture of a pulmonary valve leaflet and a membranous structure within the pulmonary artery consistent with a dissecting membrane. Short-term follow-up has shown no apparent progression of the pulmonary artery dissection and the patient remains free of clinical signs. Copyright © 2016 Elsevier B.V. All rights reserved.

Mechanism of single-frequency operation of the hybrid-CO2 laser

International Nuclear Information System (INIS)

Gondhalekar, A.; Heckenberg, N.R.; Holzhauer, E.

1975-01-01

The mechanism of a new method of obtaining high-power single-frequency pulses from a TEA-CO 2 laser is discussed. Measurements of the shape and monochromaticity of pulses from the hybrid laser which has both a TEA and a low-pressure gain section inside one resonator are presented. The mechanism of single-frequency operation of the hybrid laser is discussed with reference to numerical solutions of simplified rate equations. The low-pressure section provides gain only over a narrow range of frequencies so that a mode lying in that band-width builds up faster than neighboring modes to give a single-frequency pulse resembling in overall shape the normal TEA laser pulse. If the system is already lasing when the TEA discharge begins, the single-mode radiation already present rapidly grows to give a single-frequency pulse lacking a gain-switched peak. (U.S.)

Single ventricle cardiac defect

International Nuclear Information System (INIS)

Eren, B.; Turkmen, N.; Fedakar, R.; Cetin, V.

2010-01-01

Single ventricle heart is defined as a rare cardiac abnormality with a single ventricle chamber involving diverse functional and physiological defects. Our case is of a ten month-old baby boy who died shortly after admission to the hospital due to vomiting and diarrhoea. Autopsy findings revealed cyanosis of finger nails and ears. Internal examination revealed; large heart, weighing 60 grams, single ventricle, without a septum and upper membranous part. Single ventricle is a rare pathology, hence, this paper aims to discuss this case from a medico-legal point of view. (author)

The Renal Nerves in Chronic Heart Failure: Afferent and Efferent Mechanisms

Directory of Open Access Journals (Sweden)

Alicia Marie Schiller

2015-08-01

Full Text Available The function of the renal nerves has been an area of scientific and medical interest for many years. The recent advent of a minimally invasive catheter-based method of renal denervation has renewed excitement in understanding the afferent and efferent actions of the renal nerves in multiple diseases. While hypertension has been the focus of much this work, less attention has been given to the role of the renal nerves in the development of chronic heart failure (CHF. Recent studies from our laboratory and those of others implicate an essential role for the renal nerves in the development and progression of CHF. Using a rabbit tachycardia model of CHF and surgical unilateral renal denervation, we provide evidence for both renal efferent and afferent mechanisms in the pathogenesis of CHF. Renal denervation prevented the decrease in renal blood flow observed in CHF while also preventing increases in Angiotensin-II receptor protein in the microvasculature of the renal cortex. Renal denervation in CHF also reduced physiological markers of autonomic dysfunction including an improvement in arterial baroreflex function, heart rate variability, and decreased resting cardiac sympathetic tone. Taken together, the renal sympathetic nerves are necessary in the pathogenesis of CHF via both efferent and afferent

Myocardial Architecture, Mechanics, and Fibrosis in Congenital Heart Disease

Directory of Open Access Journals (Sweden)

Sarah Ghonim

2017-05-01

Full Text Available Congenital heart disease (CHD is the most common category of birth defect, affecting 1% of the population and requiring cardiovascular surgery in the first months of life in many patients. Due to advances in congenital cardiovascular surgery and patient management, most children with CHD now survive into adulthood. However, residual and postoperative defects are common resulting in abnormal hemodynamics, which may interact further with scar formation related to surgical procedures. Cardiovascular magnetic resonance (CMR has become an important diagnostic imaging modality in the long-term management of CHD patients. It is the gold standard technique to assess ventricular volumes and systolic function. Besides this, advanced CMR techniques allow the acquisition of more detailed information about myocardial architecture, ventricular mechanics, and fibrosis. The left ventricle (LV and right ventricle have unique myocardial architecture that underpins their mechanics; however, this becomes disorganized under conditions of volume and pressure overload. CMR diffusion tensor imaging is able to interrogate non-invasively the principal alignments of microstructures in the left ventricular wall. Myocardial tissue tagging (displacement encoding using stimulated echoes and feature tracking are CMR techniques that can be used to examine the deformation and strain of the myocardium in CHD, whereas 3D feature tracking can assess the twisting motion of the LV chamber. Late gadolinium enhancement imaging and more recently T1 mapping can help in detecting fibrotic myocardial changes and evolve our understanding of the pathophysiology of CHD patients. This review not only gives an overview about available or emerging CMR techniques for assessing myocardial mechanics and fibrosis but it also describes their clinical value and how they can be used to detect abnormalities in myocardial architecture and mechanics in CHD patients.

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

2017-10-01

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

The effect of combined conventional and modified ultrafiltration on mechanical ventilation and hemodynamic changes in congenital heart surgery

Directory of Open Access Journals (Sweden)

Mohsen Ziyaeifard

2016-01-01

Full Text Available Background: Cardiopulmonary bypass is associated with increased fluid accumulation around the heart which influences pulmonary and cardiac diastolic function. The aim of this study was to compare the effects of modified ultrafiltration (MUF versus conventional ultrafiltration (CUF on duration of mechanical ventilation and hemodynamic status in children undergoing congenital heart surgery. Materials and Methods: A randomized clinical trial was conducted on 46 pediatric patients undergoing cardiopulmonary bypass throughout their congenital heart surgery. Arteriovenous MUF plus CUF was performed in 23 patients (intervention group and sole CUF was performed for other 23 patients (control group. In MUF group, arterial cannula was linked to the filter inlet through the arterial line, and for 10 min, 10 ml/kg/min of blood was filtered and returned via cardioplegia line to the right atrium. Different parameters including hemodynamic variables, length of mechanical ventilation, Intensive Care Unit (ICU stay, and inotrope requirement were compared between the two groups. Results: At immediate post-MUF phase, there was a statistically significant increase in the mean arterial pressure, systolic blood pressure, and diastolic blood pressure (P < 0.05 only in the study group. Furthermore, there was a significant difference in time of mechanical ventilation (P = 0.004 and ICU stay (P = 0.007 between the two groups. Inotropes including milrinone (P = 0.04, epinephrine (P = 0.001, and dobutamine (P = 0.002 were used significantly less frequently for patients in the intervention than the control group. Conclusion: Administration of MUF following surgery improves hemodynamic status of patients and also significantly decreases the duration of mechanical ventilation and inotrope requirement within 48 h after surgery.

Education on tick bite and Lyme borreliosis prevention, aimed at schoolchildren in the Netherlands: comparing the effects of an online educational video game versus a leaflet or no intervention.

Science.gov (United States)

Beaujean, D J M A; Gassner, F; Wong, A; Steenbergen, J E; Crutzen, R; Ruwaard, D

2016-11-16

Lyme disease or Lyme borreliosis (LB) is the most common tick-borne disease both in the United States and Europe. Children, in particular, are at high risk of contracting LB. Since child-specific educational tools on ticks, tick bites and LB are lacking, we developed an online educational video game. In this study, we compared the effectiveness of an online educational video game versus a newly developed leaflet aimed to improve prevention of tick bites and LB among Dutch schoolchildren. A total of 887 children, aged 9-13 years and attending the two final years of primary schooling, were recruited from 25 primary schools in June and July 2012. They were assigned through cluster randomization to one of three intervention groups: 'game' (22.4%), 'leaflet' (35.6%) or 'control' (41.9%). Prior to and directly following intervention, the children were asked to complete a short questionnaire. The main outcome measures were knowledge, perception (perceived susceptibility and importance) and preventive behavior in relation to tick bites and LB. Generalized linear mixed models were used to analyze the data. In the game group, the leaflet group and the control group, knowledge about ticks and tick bites improved significantly. The game was also an effective tool for improving preventive behavior; the frequency of checking for ticks increased significantly. However, there were no significant differences in knowledge improvement between the interventions. The game outperformed the leaflet in terms of improving preventive behavior, whereas the frequency of tick checks increased significantly. But this frequency didn't increase more than in the control group. The positive knowledge effects observed in the control group suggests the presence of a mere measurement effect related to completion of the questionnaire. The game did not outperform the leaflet or control group on all outcome measures. Therefore, the game may be of value as a complementary role, in addition to other media

Screening for coronary artery disease in respiratory patients: comparison of single- and dual-source CT in patients with a heart rate above 70 bpm

International Nuclear Information System (INIS)

Pansini, Vittorio; Remy-Jardin, Martine; Tacelli, Nunzia; Faivre, Jean-Baptiste; Remy, Jacques; Flohr, Thomas; Deken, Valerie; Duhamel, Alain

2008-01-01

To evaluate the assessibility of coronary arteries in respiratory patients with high heart rates. This study was based on the comparative analysis of two paired populations of 54 patients with a heart rate >70 bpm evaluated with dual-source (group 1) and single-source (group 2) CT. The mean heart rate was 89.1 bpm in group 1 and 86.7 bpm in group 2 (P=0.26). The mean number of assessable segments per patient was significantly higher in group 1 compared to group 2 (P≤0.0001). The proportions of patients in whom proximal and mid-coronary segments were assessable (i.e., the anatomical level enabling screening for asymptomatic coronary artery disease) were 35.3% for heart rates <110 bpm, 35.6% for heart rates <100 bpm, 40% for heart rates <90 bpm, and 60% for heart rates <80 bpm in group 1 and 11.3, 12.2, 8.8, and 10% for the corresponding thresholds in group 2 (P<0.05). In both groups of patients, coronary artery imaging was obtained from standard CT angiograms of the chest. The improvement in coronary imaging with dual-source CT suggests that high heart rates should no longer be considered as contraindications for ECG-gated CT angiograms of the chest whenever clinically relevant. (orig.)

Verification of Pharmacogenetics-Based Warfarin Dosing Algorithms in Han-Chinese Patients Undertaking Mechanic Heart Valve Replacement

Science.gov (United States)

Zhao, Li; Chen, Chunxia; Li, Bei; Dong, Li; Guo, Yingqiang; Xiao, Xijun; Zhang, Eryong; Qin, Li

2014-01-01

Objective To study the performance of pharmacogenetics-based warfarin dosing algorithms in the initial and the stable warfarin treatment phases in a cohort of Han-Chinese patients undertaking mechanic heart valve replacement. Methods We searched PubMed, Chinese National Knowledge Infrastructure and Wanfang databases for selecting pharmacogenetics-based warfarin dosing models. Patients with mechanic heart valve replacement were consecutively recruited between March 2012 and July 2012. The predicted warfarin dose of each patient was calculated and compared with the observed initial and stable warfarin doses. The percentage of patients whose predicted dose fell within 20% of their actual therapeutic dose (percentage within 20%), and the mean absolute error (MAE) were utilized to evaluate the predictive accuracy of all the selected algorithms. Results A total of 8 algorithms including Du, Huang, Miao, Wei, Zhang, Lou, Gage, and International Warfarin Pharmacogenetics Consortium (IWPC) model, were tested in 181 patients. The MAE of the Gage, IWPC and 6 Han-Chinese pharmacogenetics-based warfarin dosing algorithms was less than 0.6 mg/day in accuracy and the percentage within 20% exceeded 45% in all of the selected models in both the initial and the stable treatment stages. When patients were stratified according to the warfarin dose range, all of the equations demonstrated better performance in the ideal-dose range (1.88–4.38 mg/day) than the low-dose range (warfarin dose prediction and in the low-dose and the ideal-dose ranges. Conclusions All of the selected pharmacogenetics-based warfarin dosing regimens performed similarly in our cohort. However, the algorithms of Wei, Huang, and Miao showed a better potential for warfarin prediction in the initial and the stable treatment phases in Han-Chinese patients undertaking mechanic heart valve replacement. PMID:24728385

Effect of mibefradil on heart rate variability in patients with chronic heart failure

NARCIS (Netherlands)

Brouwer, J; de Kam, PJ; Haaksma, J; Crijns, HJGM; van Veldhuisen, DJ

2000-01-01

Background: Mibefradil was recently withdrawn from the market because of an unfavorable clinical profile in patients with chronic heart failure. Although drug interactions appear to play a role, other mechanisms such as proarrhythmia and autonomic deterioration could also be relevant. Chronic heart

Exploration of mechanisms underlying the strain-rate-dependent mechanical property of single chondrocytes

Energy Technology Data Exchange (ETDEWEB)

Nguyen, Trung Dung; Gu, YuanTong, E-mail: yuantong.gu@qut.edu.au [School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane, Queensland (Australia)

2014-05-05

Based on the characterization by Atomic Force Microscopy, we report that the mechanical property of single chondrocytes has dependency on the strain-rates. By comparing the mechanical deformation responses and the Young's moduli of living and fixed chondrocytes at four different strain-rates, we explore the deformation mechanisms underlying this dependency property. We found that the strain-rate-dependent mechanical property of living cells is governed by both of the cellular cytoskeleton and the intracellular fluid when the fixed chondrocytes are mainly governed by their intracellular fluid, which is called the consolidation-dependent deformation behavior. Finally, we report that the porohyperelastic constitutive material model which can capture the consolidation-dependent behavior of both living and fixed chondrocytes is a potential candidature to study living cell biomechanics.

The Total Artificial Heart in End-Stage Congenital Heart Disease.

Science.gov (United States)

Villa, Chet R; Morales, David L S

2017-01-01

The development of durable ventricular assist devices (VADs) has improved mortality rates and quality of life in patients with end stage heart failure. While the use of VADs has increased dramatically in recent years, there is limited experience with VAD implantation in patients with complex congenital heart disease (CHD), despite the fact that the number of patients with end stage CHD has grown due to improvements in surgical and medical care. VAD use has been limited in patients with CHD and end stage heart failure due to anatomic (systemic right ventricle, single ventricle, surgically altered anatomy, valve dysfunction, etc.) and physiologic constraints (diastolic dysfunction). The total artificial heart (TAH), which has right and left sided pumps that can be arranged in a variety of orientations, can accommodate the anatomic variation present in CHD patients. This review provides an overview of the potential use of the TAH in patients with CHD.

Use of Prothrombin Complex Concentrate in Patients during Heart Transplantation after Implantation of a Left Ventricular Mechanical Support System

Directory of Open Access Journals (Sweden)

V. V. Lomivorotov

2012-01-01

Full Text Available Heart transplantation in patients after implantation of mechanical cardiac support devices entails an extremely high risk for perioperative bleeding. Recombinant activated coagulation factor VII is presently used to reduce the volume of bleeding in this patient group. There are parallel data on its administration-induced thromboembolic events in the literature. This paper describes a case of using a prothrombin complex concentrate in a patient during explantation of a left ventricular bypass system and subsequent orthotopic heart transplantation in the presence of significant hypocoagulation. At the end of a surgery, 1200 IU of the agent was used at a remaining bleeding rate of more than 1000 ml/hour. Within the first 24 hours after surgery, the rate of discharge drainage was less than 100 ml/hour. A control plain chest X-ray study revealed massive left-sided hydrothorax on day 2 postsurgery. The left pleural cavity was revised under thoracoscopic guidance and 1000 ml of blood clots were evacuated. Although the administration of prothrombin complex concentrate did not guard against re-intervention, its use seems a promising strategy in life-threatening bleedings in patients after explantation of mechanical cardiac support devices. Further multicenter investigations are required to determine the efficacy and safety of prothrom-bin complex concentration in cardiac surgery. Key words: Recombinant activated coagulation factor VII, prothrombin complex concentration, mechanical cardiac support device, orthotopic heart transplantation.

Forkhead box transcription factors in embryonic heart development and congenital heart disease.

Science.gov (United States)

Zhu, Hong

2016-01-01

Embryonic heart development is a very complicated process regulated precisely by a network composed of many genes and signaling pathways in time and space. Forkhead box (Fox, FOX) proteins are a family of transcription factors characterized by the presence of an evolutionary conserved "forkhead"or "winged-helix" DNA-binding domain and able to organize temporal and spatial gene expression during development. They are involved in a wide variety of cellular processes, such as cell cycle progression, proliferation, differentiation, migration, metabolism and DNA damage response. An abundance of studies in model organisms and systems has established that Foxa2, Foxc1/c2, Foxh1 and Foxm1, Foxos and Foxps are important components of the signaling pathways that instruct cardiogenesis and embryonic heart development, playing paramount roles in heart development. The previous studies also have demonstrated that mutations in some of the forkhead box genes and the aberrant expression of forkhead box gene are heavily implicated in the congenital heart disease (CHD) of humans. This review primarily focuses on the current understanding of heart development regulated by forkhead box transcription factors and molecular genetic mechanisms by which forkhead box factors modulate heart development during embryogenesis and organogenesis. This review also summarizes human CHD related mutations in forkhead box genes as well as the abnormal expression of forkhead box gene, and discusses additional possible regulatory mechanisms of the forkhead box genes during embryonic heart development that warrant further investigation. Copyright © 2015 Elsevier Inc. All rights reserved.

Outcome of double vs. single valve replacement for rheumatic heart disease

International Nuclear Information System (INIS)

Akhtar, R.P.; Abid, A.R.

2010-01-01

To compare the follow-up results of double valve replacement (DVR) i.e. mitral valve replacement (MVR) and aortic valve replacement (AVR) vs. isolated MVR or AVR for rheumatic heart disease. Study Design: An interventional qausi-experimental study. Prospective follow-up of 493 patients with mechanical heart valves was carried out using clinical assessment, international normalized ratio and echocardiography. Patients were divided into three groups: group I having MVR, group II having AVR and group III having DVR. Survival, time and causes of mortality, and frequency of valve thrombosis, haemorrhage and cerebrovascular haemorrhage was noted in the three groups and described as proportions. Actuarial survival was analyzed by Kaplan-Meier method. There were 493 with 287 (58.3%) in group I, 87 (17.6%) in group II and 119 (24.1%) in group III. Total follow-up was 2429.2 patient (pt)-years. Of 77 (15.6%) deaths, 19 (3.8%) were in-hospital and 58 (11.8%) were late. In-hospital mortality was highest 4 (4.6%) in group II followed by 5 (4.2%) group III and 10 (3.5%) group I. Late deaths were 39 (13.4%) in group I, 9 (10.2%) in group II and 10 (8.3%) in group III. The total actuarial survival was 84.4% with survival of 83%, 85.1%, 87.4% in groups I, II and III respectively. On follow-up valve thrombosis occurred in 12 (0.49%/pt-years) patients; 9 (0.67%/pt-years) group I, 1 (0.22%/pt-years) in group II and 2 (0.31%/pt-years) in group III. Severe haemorrhage occurred in 19 (0.78%/pt-years); 14 in (1.04%/pt-years) in group I, 3 (0.66%/pt-years) group II and 2 (0.31%/pt-years) in group III. Cerebrovascular accidents occurred in 34 (1.3%/pt-years); 26 (1.95%/pt-years) in group I and 4 in groups II (0.89%/pt-years) and III (0.62%/pt-years) each. In patients with rheumatic heart disease having combined mitral and aortic valve disease DVR should be performed whenever indicated as it has similar in-hospital mortality and better late survival as compared to isolated aortic or mitral

A quality assessment of patient leaflets on misoprostol induced labour – does written information adhere to international standards for patient involvement and informed consent?

DEFF Research Database (Denmark)

Clausen, Jette Aaroe; Juul, Mette; Rydahl, Eva

Objectives: The need for thorough patient information is increasing as maternity care becomes more medicalised. The aim was to assess the quality of written patient information on labour induction. In most Danish hospitals misoprostol is the first-choice drug for induction in low-risk pregnancies......). Design: Patient leaflets were evaluated according to a validated scoring tool (IPDAS), core elements in The Danish Health Act, and items regarding off-label use and non-registered medication. Two of the authors scored all leaflets independently. Outcome measures: Women’s involvement in decision making......, and information on benefits and harms associated with the treatment, other justifiable treatment options, and non-registered treatment. Results: Generally, the hospitals scored low on the IPDAS checklist. No hospitals encouraged women to consider their preferences. Information on side-effects and adverse outcomes...

Impact of Mediterranean diet education versus posted leaflet on dietary habits and serum cholesterol in a high risk population for cardiovascular disease

NARCIS (Netherlands)

Bemelmans, Wanda J. E.; Broer, Jan; de Vries, Jeanne H. M.; Hulshof, Karin F. A. M.; May, Jo F.; Meyboom-de Jong, Betty

Objective: To investigate the impact of intensive group education on the Mediterranean diet on dietary intake and serum total cholesterol after 16 and 52 weeks, compared to a posted leaflet with the Dutch nutritional guidelines, in the context of primary prevention of cardiovascular disease (CVD).

Comparison of platelet activation through hinge vs bulk flow in mechanical heart valves

Science.gov (United States)

Hedayat, Mohammadali; Borazjani, Iman

2017-11-01

Bileaflet mechanical heart valves increase the risk of thrombus formation in patients which is believed to be initiated by platelet activation. Platelets can be activated by the elevated shear stresses in the bulk flow during the systole phase or the flow through the hinge during the diastole. However, the importance of platelet activation by the bulk flow vs the hinge in MHVs has yet to be studied. Here, we investigate the contribution of each of the above mechanisms to the activation of platelets in MHs by performing simulation of the flow through a 25mm St. Jude Medical valve placed in a straight aorta. Two different gap sizes (250 and 150 micrometer) are used in this study. The simulations are done using a sharp interface curvilinear immersed boundary method along with a strong-coupling algorithm for FSI solver on overset grids. The platelet activation through the hinge for different gap sizes is compared to the activation in the bulk flow using two platelet activation models to ensure the consistency of the results. Our results for all gap sizes using different activation models show that the integration of platelet activation caused by the bulk flow is several times higher in comparison to the activation through the hinge. 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.

Examination of mitral regurgitation with a goat heart model for the development of intelligent artificial papillary muscle.

Science.gov (United States)

Shiraishi, Y; Yambe, T; Yoshizawa, M; Hashimoto, H; Yamada, A; Miura, H; Hashem, M; Kitano, T; Shiga, T; Homma, D

2012-01-01

Annuloplasty for functional mitral or tricuspid regurgitation has been made for surgical restoration of valvular diseases. However, these major techniques may sometimes be ineffective because of chamber dilation and valve tethering. We have been developing a sophisticated intelligent artificial papillary muscle (PM) by using an anisotropic shape memory alloy fiber for an alternative surgical reconstruction of the continuity of the mitral structural apparatus and the left ventricular myocardium. This study exhibited the mitral regurgitation with regard to the reduction in the PM tension quantitatively with an originally developed ventricular simulator using isolated goat hearts for the sophisticated artificial PM. Aortic and mitral valves with left ventricular free wall portions of isolated goat hearts (n=9) were secured on the elastic plastic membrane and statically pressurized, which led to valvular leaflet-papillary muscle positional change and central mitral regurgitation. PMs were connected to the load cell, and the relationship between the tension of regurgitation and PM tension were measured. Then we connected the left ventricular specimen model to our hydraulic ventricular simulator and achieved hemodynamic simulation with the controlled tension of PMs.

Pathological mechanisms underlying single large‐scale mitochondrial DNA deletions

Science.gov (United States)

Rocha, Mariana C.; Rosa, Hannah S.; Grady, John P.; Blakely, Emma L.; He, Langping; Romain, Nadine; Haller, Ronald G.; Newman, Jane; McFarland, Robert; Ng, Yi Shiau; Gorman, Grainne S.; Schaefer, Andrew M.; Tuppen, Helen A.; Taylor, Robert W.

2018-01-01

Objective Single, large‐scale deletions in mitochondrial DNA (mtDNA) are a common cause of mitochondrial disease. This study aimed to investigate the relationship between the genetic defect and molecular phenotype to improve understanding of pathogenic mechanisms associated with single, large‐scale mtDNA deletions in skeletal muscle. Methods We investigated 23 muscle biopsies taken from adult patients (6 males/17 females with a mean age of 43 years) with characterized single, large‐scale mtDNA deletions. Mitochondrial respiratory chain deficiency in skeletal muscle biopsies was quantified by immunoreactivity levels for complex I and complex IV proteins. Single muscle fibers with varying degrees of deficiency were selected from 6 patient biopsies for determination of mtDNA deletion level and copy number by quantitative polymerase chain reaction. Results We have defined 3 “classes” of single, large‐scale deletion with distinct patterns of mitochondrial deficiency, determined by the size and location of the deletion. Single fiber analyses showed that fibers with greater respiratory chain deficiency harbored higher levels of mtDNA deletion with an increase in total mtDNA copy number. For the first time, we have demonstrated that threshold levels for complex I and complex IV deficiency differ based on deletion class. Interpretation Combining genetic and immunofluorescent assays, we conclude that thresholds for complex I and complex IV deficiency are modulated by the deletion of complex‐specific protein‐encoding genes. Furthermore, removal of mt‐tRNA genes impacts specific complexes only at high deletion levels, when complex‐specific protein‐encoding genes remain. These novel findings provide valuable insight into the pathogenic mechanisms associated with these mutations. Ann Neurol 2018;83:115–130 PMID:29283441

Living with half a heart - experiences of young adults with single ventricle physiology

DEFF Research Database (Denmark)

Overgaard, Dorthe; King, Catriona; Christensen, Rie F

2013-01-01

Background and Research Objective: Approximately 3% of children with congenital heart disease born in Denmark have single ventricle physiology (SVP). In previous decades, these children did not survive into adulthood. However, because of new surgical techniques and improved medical care, they now...... have a 90% survival rate. Several studies have described the somatic status of SVP patients using clinical parameters; however, only a few studies have researched the life perspectives and coping skills in this patient group. The aim of this study was to investigate how young adults with an SVP...... diagnosis are coping with adulthood and the emotional experiences of daily life. Subjects and Methods: Semistructured, qualitative interviews were held with 11 SVP respondents, selected by physical and psychological parameters identified in an earlier quantitative study. Data from the interviews were...

Fully quantum-mechanical dynamic analysis of single-photon transport in a single-mode waveguide coupled to a traveling-wave resonator

International Nuclear Information System (INIS)

Hach, Edwin E. III; Elshaari, Ali W.; Preble, Stefan F.

2010-01-01

We analyze the dynamics of single-photon transport in a single-mode waveguide coupled to a micro-optical resonator by using a fully quantum-mechanical model. We examine the propagation of a single-photon Gaussian packet through the system under various coupling conditions. We review the theory of single-photon transport phenomena as applied to the system and we develop a discussion on the numerical technique we used to solve for dynamical behavior of the quantized field. To demonstrate our method and to establish robust single-photon results, we study the process of adiabatically lowering or raising the energy of a single photon trapped in an optical resonator under active tuning of the resonator. We show that our fully quantum-mechanical approach reproduces the semiclassical result in the appropriate limit and that the adiabatic invariant has the same form in each case. Finally, we explore the trapping of a single photon in a system of dynamically tuned, coupled optical cavities.

[Effects of using an information leaflet in reducing perioperative anxiety and pain in patients undergoing urological surgery].

Science.gov (United States)

Miguel Romeo, M Carmen; Sagardoy Muniesa, Lorena

2014-01-01

The preoperative anxiety state is mainly caused by the fear of the circumstances surrounding the intervention. Anxiety causes increased postoperative pain, and a prolonged length of stay in hospital, which directly affect the cost of care. To evaluate the effects of providing an anaesthesia information leaflet on postoperative anxiety and pain in patients undergoing urological surgery in the Miguel Servet Hospital. A prospective quasi-experimental study of 100 cases, 51 of whom made up the intervention group who received the information leaflet, with the remaining 49 cases being in the control group. The Hospital Anxiety and Depression Scale and the visual analogue scale for pain were assessed in both groups, before and after surgery. Of the 100 patients, 72% were male and 28% female, with an average age of 67.3 years (standard deviation, 9.7). In the intervention group, 21.6% showed anxiety before surgery and 0% in the postoperative period. In the control group 30.6% presented anxiety during the preoperative period and 4% in the postoperative period (χ(2) Pearson 5.20, P=.023). The study showed a direct relationship between preoperative anxiety and postoperative pain (χ(2) Pearson 10.519, P=.001). Good information about the surgical process reduces anxiety levels in the postoperative period. Copyright © 2013 Elsevier España, S.L. All rights reserved.

Radiation-induced damage of the Wistar Rat heart

International Nuclear Information System (INIS)

Cilliers, G.D.; Lochner, A.

1993-01-01

A time sequence study was performed on Wistar rats to investigate the early effects of radiation on the mechanical function and energy metabolism of the heart. Two series of rats were exposed to 20 Gy electron irradiation to a field including the heart and approximately a third of the lungs. The hearts were excised at varying time intervals (8-180 days) post irradiation. In one series of hearts the mechanical function was measured using the isolated perfused working rat heart model. At the end of the perfusion the hearts were freeze-clamped for analysis of the high energy phosphate contents (ATP, ADP, AMP and creatine phosphate). In the second series, mitochondria were isolated and the oxidative phosphorylation function measured polarographically (substrate: glutamate). Maximal depression of mechanical function was observed at 60 days post irradiation. Thereafter the work performance of these hearts improved significantly, almost reaching control levels after 180 days. The mitochondrial oxidative phosphorylation function (as measured on the total mitochondrial population) was significantly depressed 30-120 days post irradiation. As in the case of the mechanical changes, the depression was transient and after 180 days post irradiation, values similar to those of controls were obtained. Myocardial high energy phosphates remained unaltered throughout the experiment. (author)

Heart Failure in Women

Science.gov (United States)

Bozkurt, Biykem; Khalaf, Shaden

2017-01-01

Heart failure is an important cause of morbidity and mortality in women, and they tend to develop it at an older age compared to men. Heart failure with preserved ejection fraction is more common in women than in men and accounts for at least half the cases of heart failure in women. When comparing men and women who have heart failure and a low left ventricular ejection fraction, the women are more symptomatic and have a similarly poor outcome. Overall recommendations for guideline-directed medical therapies show no differences in treatment approaches between men and women. Overall, women are generally underrepresented in clinical trials for heart failure. Further studies are needed to shed light into different mechanisms, causes, and targeted therapies of heart failure in women. PMID:29744014

Usefulness of the myocardial performance index determined by tissue Doppler imaging m-mode for predicting mortality in the general population

DEFF Research Database (Denmark)

Biering-Sørensen, Tor; Møgelvang, Rasmus; Haahr-Pedersen, Sune Ammentorp

2011-01-01

The objective of this study was to evaluate the prognostic value of the myocardial performance index (MPI), assessed by color-coded tissue Doppler imaging (TDI) M-mode through the anterior mitral leaflet. Color TDI M-mode through the mitral leaflet is an easy, very fast, and precise method...... ventricular in- and outflow using standard procedures (MPI(conv)) and by color-coded TDI M-mode through the mitral leaflet in the apical 4-chamber view (MPI(TDI)). MPI(TDI) was increased in subjects with coronary heart disease (CHD) compared to controls, even after multivariable adjustment (p

Biosynthesis of the Essential Fatty Acid Oxidation Cofactor Carnitine Is Stimulated in Heart and Liver after a Single Bout of Exercise in Mice

Directory of Open Access Journals (Sweden)

Tom L. Broderick

2018-01-01

Full Text Available We determined whether one single bout of exercise stimulates carnitine biosynthesis and carnitine uptake in liver and heart. Free carnitine (FC in plasma was assayed using acetyltransferase and [14C]acetyl-CoA in Swiss Webster mice after 1 hour of moderate-intensity treadmill running or 4 hours and 8 hours into recovery. Liver and heart were removed under the same conditions for measurement of carnitine biosynthesis enzymes (liver butyrobetaine hydroxylase, γ-BBH; heart trimethyllysine dioxygenase, TMLD, organic cation transporter-2 (OCTN2, carnitine transporter, and liver peroxisome proliferator-activated receptor-alpha (PPARα, transcription factor for γ-BBH and OCTN2 synthesis. In exercised mice, FC levels in plasma decreased while heart and liver OCTN2 protein expressed increased, reflecting active uptake of FC. During recovery, the rise in FC to control levels was associated with increased liver γ-BBH expression. Protein expression of PPARα was stimulated in liver after exercise and during recovery. Interestingly, heart TMLD protein was also detected after exercise. Acute exercise stimulates carnitine uptake in liver and heart. The rapid return of FC levels in plasma after exercise indicates carnitine biosynthesis by liver is stimulated to establish carnitine homeostasis. Our results suggest that exercise may benefit patients with carnitine deficiency syndromes.

Decreased mechanical properties of heart valve tissue constructs cultured in platelet lysate as compared to fetal bovine serum

NARCIS (Netherlands)

Geemen, van D.; Riem Vis, P.W.; Soekhradj - Soechit, R.S.; Sluijter, J.P.G.; Liefde - van Beest, de M.; Kluin, J.; Bouten, C.V.C.

2011-01-01

In autologous heart valve tissue engineering, there is an ongoing search for alternatives of fetal bovine serum (FBS). Human platelet-lysate (PL) might be a promising substitute. In the present article, we aimed to examine the tissue formation, functionality, and mechanical properties of engineered

Excitation mechanisms in singly ionized krypton laser

International Nuclear Information System (INIS)

El-Sherbini, Th.M.

1982-01-01

Lifetimes for the low lying 4p 4 4d and 4p 4 5s levels of singly ionized krypton laser are calculated, taking into account configuration interaction effects. The results show that some of these levels are metastable. They also suggest a two step excitation from the ground state of the ion (or the atom) to the upper 4p 4 5p laser levels involving some intermediate metastable states as a possible excitation mechanism. (author)

In vivo evaluation of expression of TGFβ1 in the irradiated heart

International Nuclear Information System (INIS)

Affonso Junior, Renato Jose; Oshima, Celina Tizuko Fujiyama; Silva, Maria Regina Regis; Kimura, Edna Teruko; Egami, Mizue Imoto; Segreto, Roberto Araujo; Segreto, Helena Regina Comodo

2004-01-01

The objectives of this study were to assess the latent and active TGFβ1 localization in the heart, to evaluate whether or not radiation induces latent TGFβ1 activation, and to study the distribution of collagen fibers in the irradiated heart. Thirty-two C 57 BL mice were randomly assigned in two groups: GI (non irradiated animals) and GII (irradiated animals). The mice from G II received a single whole-body radiation dose of 7 Gy, using a 60 Co source at a dose rate of 0.97 Gy/min. The animals were sacrificed by cervical dislocation at 1, 14, 30 and 90 days after irradiation. The irradiated hearts showed: nuclear changes and muscle cells with decreased striations; significant increase in the collagen deposition 90 days after irradiation; latent TGFβ1 activation in the cardio myocytes and connective tissue cells after irradiation. Our results show the importance of TGFβ1 protein in the process of radiation-induced heart fibrosis and suggest that cardio myocytes and connective cells may play a role in this mechanism acting as cellular sources of active TGFβ1. (author)

Single-source mechanical loading system produces biaxial stresses in cylinders

Science.gov (United States)

Flower, J. F.; Stafford, R. L.

1967-01-01

Single-source mechanical loading system proportions axial-to-hoop tension loads applied to cylindrical specimens. The system consists of hydraulic, pneumatic, and lever arrangements which produce biaxial loading ratios.

Demikhov's "Mechanical Heart": The Circumstances Surrounding Creation of the World's First Implantable Total Artificial Heart in 1937.

Science.gov (United States)

Glyantsev, Sergey P; Tchantchaleishvili, Vakhtang; Bockeria, Leo A

2016-01-01

The world's first implantable total artificial heart was designed by Vladimir Demikhov as a fourth year biology student in Voronezh, Soviet Union, in 1937. As a prototype of his device, Demikhov must have used an apparatus for extracorporeal blood circulation invented by Sergei Bryukhonenko of Moscow. The device was the size of a dog's native heart and consisted of two diaphragm pumps brought into motion by an electric motor. A dog with an implanted device lived for 2.5 hours. In addition to having the prototype, the preconditions for Demikhov's artificial heart creation were his manual dexterity, expertise in animal physiology, and his mechanistic worldview.

The Evolution of Mitral Valve Prolapse: Insights from the Framingham Heart Study

Science.gov (United States)

Delling, Francesca N.; Rong, Jian; Larson, Martin G.; Lehman, Birgitta; Fuller, Deborah; Osypiuk, Ewa; Stantchev, Plamen; Hackman, Brianne; Manning, Warren J.; Benjamin, Emelia J.; Levine, Robert A.; Vasan, Ramachandran S.

2016-01-01

Background Longitudinal studies of mitral valve prolapse (MVP) progression among unselected individuals in the community, including those with non-diagnostic MVP morphologies (NDM), are lacking. Methods and Results We measured longitudinal changes in annular diameter, leaflet displacement, thickness, anterior/posterior leaflet projections onto the annulus, coaptation height, and mitral regurgitation (MR) jet height in 261 Framingham Offspring participants at Examination 5 who had available follow-up imaging 3 to 16 years later. Study participants included MVP (N=63), NDM - ‘minimal systolic displacement’ or MSD (N=50) and the ‘abnormal anterior coaptation’ (AAC) phenotype (N=10, with coaptation height >40% of the annulus similar to posterior MVP), plus 138 healthy referents without MVP or NDM. At follow-up, individuals with MVP (52% women, 57±11 years) had greater increases of leaflet displacement, thickness, and jet height compared with referents (all pMVP (17%) had ≥ moderate MR (jet height ≥5 mm) and 5 others (8%) underwent mitral valve repair. Of the individuals with NDM, 8 (80%) AACs progressed to posterior MVP; 17 (34%) MSDs were reclassified as either posterior MVP (12) or AAC (5). Compared with the 33 MSDs who did not progress, the 17 who progressed had greater leaflet displacement, thickness, coaptation height, and MR jet height (all pMVP, highlighting the clinical significance of mild MVP expression. MVP progresses to significant MR over a period of 3 to 16 years in a quarter of individuals in the community. Changes in mitral leaflet morphology are associated with both NDM and MVP progression. PMID:27006478

Respiratory induced heart rate variability during slow mechanical ventilation Marker to exclude brain death patients

Czech Academy of Sciences Publication Activity Database

Jurák, Pavel; Halámek, Josef; Vondra, Vlastimil; Kružliak, P.; Šrámek, V.; Cundrle, I.; Leinveber, P.; Adamek, M.; Zvoníček, V.

2017-01-01

Roč. 129, 7-8 (2017), s. 251-258 ISSN 0043-5325 R&D Projects: GA ČR GAP103/11/0933; GA MŠk(CZ) LO1212; GA MŠk ED0017/01/01; GA MZd NS10105 Institutional support: RVO:68081731 Keywords : critical illness * sedation * brain death * respiratory rate variability * heart rate variability * mechanical ventilation Subject RIV: FS - Medical Facilities ; Equipment OBOR OECD: Medical engineering Impact factor: 0.974, year: 2016

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.

Conjoined twins: morphogenesis of the heart and a review.

Science.gov (United States)

Gilbert-Barness, Enid; Debich-Spicer, Diane; Opitz, John M

2003-08-01

Five cases of conjoined twins have been studied. These included three thoracopagus twins, one monocephalus diprosopus (prosop = face), and one dicephalus dipus dibrachus. The thoracopagus twins were conjoined only from the upper thorax to the umbilicus with a normal foregut. These three cases shared a single complex multiventricular heart, one with a four chambered heart with one atrium and one ventricle belonging to each twin with complex venous and arterial connection; two had a seven chambered heart with four atria and three ventricles. The mono-cephalus diprosopus twins had a single heart with tetralogy of Fallot. The dicephalus twins had two separate axial skeletons to the sacrum, two separate hearts were connected between the right atria with a shared inferior vena cava. Thoracopagus twinning is associated with complex cardiac malformations. The cardiac anlagen in cephalopagus or diprosopus are diverted and divided along with the entire rostral end of the embryonic disc and result in two relatively normal shared hearts. However, in thoracopagus twins the single heart is multiventricular and suggests very early union with fusion of the cardiac anlagen before significant differentiation. Cardiac morphogenesis in conjoined twins therefore appears to depend on the site of the conjoined fusion and the temporal and spatial influence that determines morphogenesis as well as abnormally oriented embryonic axes. Copyright 2003 Wiley-Liss, Inc.

Strengthening mechanisms of Fe nanoparticles for single crystal Cu–Fe alloy

International Nuclear Information System (INIS)

Shi, Guodong; Chen, Xiaohua; Jiang, Han; Wang, Zidong; Tang, Hao; Fan, Yongquan

2015-01-01

A single crystal Cu–Fe alloy with finely dispersed precipitate Fe nanoparticles was fabricated in this study. The interface relationship of iron nanoparticle and copper matrix was analyzed with a high-resolution transmission electron microscope (HRTEM), and the effect of Fe nanoparticles on mechanical properties of single crystal Cu–Fe alloy was discussed. Results show that, the finely dispersed Fe nanoparticles can be obtained under the directional solidification condition, with the size of 5–50 nm and the coherent interface between the iron nanoparticle and the copper matrix. Single crystal Cu–Fe alloy possesses improved tensile strength of 194.64 MPa, and total elongation of 44.72%, respectively, at room temperature, in contrast to pure Cu sample. Nanoparticles which have coherent interface with matrix can improve the dislocation motion state. Some dislocations can slip through the nanoparticle along the coherent interface and some dislocations can enter into the nanoparticles. Thus to improve the tensile strength of single crystal Cu–Fe alloy without sacrificing the ductility simultaneously. Based on the above analyses, strengthening mechanisms of Fe nanoparticles for single crystal Cu–Fe alloy was described

Face Validity of the Single Work Ability Item: Comparison with Objectively Measured Heart Rate Reserve over Several Days

Science.gov (United States)

Gupta, Nidhi; Jensen, Bjørn Søvsø; Søgaard, Karen; Carneiro, Isabella Gomes; Christiansen, Caroline Stordal; Hanisch, Christiana; Holtermann, Andreas

2014-01-01

Purpose: The purpose of this study was to investigate the face validity of the self-reported single item work ability with objectively measured heart rate reserve (%HRR) among blue-collar workers. Methods: We utilized data from 127 blue-collar workers (Female = 53; Male = 74) aged 18–65 years from the cross-sectional “New method for Objective Measurements of physical Activity in Daily living (NOMAD)” study. The workers reported their single item work ability and completed an aerobic capacity cycling test and objective measurements of heart rate reserve monitored with Actiheart for 3–4 days with a total of 5,810 h, including 2,640 working hours. Results: A significant moderate correlation between work ability and %HRR was observed among males (R = −0.33, P = 0.005), but not among females (R = 0.11, P = 0.431). In a gender-stratified multi-adjusted logistic regression analysis, males with high %HRR were more likely to report a reduced work ability compared to males with low %HRR [OR = 4.75, 95% confidence interval (95% CI) = 1.31 to 17.25]. However, this association was not found among females (OR = 0.26, 95% CI 0.03 to 2.16), and a significant interaction between work ability, %HRR and gender was observed (P = 0.03). Conclusions: The observed association between work ability and objectively measured %HRR over several days among male blue-collar workers supports the face validity of the single work ability item. It is a useful and valid measure of the relation between physical work demands and resources among male blue-collar workers. The contrasting association among females needs to be further investigated. PMID:24840350

Face Validity of the Single Work Ability Item: Comparison with Objectively Measured Heart Rate Reserve over Several Days

Directory of Open Access Journals (Sweden)

Nidhi Gupta

2014-05-01

Full Text Available Purpose: The purpose of this study was to investigate the face validity of the self-reported single item work ability with objectively measured heart rate reserve (%HRR among blue-collar workers. Methods: We utilized data from 127 blue-collar workers (Female = 53; Male = 74 aged 18–65 years from the cross-sectional “New method for Objective Measurements of physical Activity in Daily living (NOMAD” study. The workers reported their single item work ability and completed an aerobic capacity cycling test and objective measurements of heart rate reserve monitored with Actiheart for 3–4 days with a total of 5,810 h, including 2,640 working hours. Results: A significant moderate correlation between work ability and %HRR was observed among males (R = −0.33, P = 0.005, but not among females (R = 0.11, P = 0.431. In a gender-stratified multi-adjusted logistic regression analysis, males with high %HRR were more likely to report a reduced work ability compared to males with low %HRR [OR = 4.75, 95% confidence interval (95% CI = 1.31 to 17.25]. However, this association was not found among females (OR = 0.26, 95% CI 0.03 to 2.16, and a significant interaction between work ability, %HRR and gender was observed (P = 0.03. Conclusions: The observed association between work ability and objectively measured %HRR over several days among male blue-collar workers supports the face validity of the single work ability item. It is a useful and valid measure of the relation between physical work demands and resources among male blue-collar workers. The contrasting association among females needs to be further investigated.

Single-molecule mechanics of protein-labelled DNA handles

Directory of Open Access Journals (Sweden)

Vivek S. Jadhav

2016-01-01

Full Text Available DNA handles are often used as spacers and linkers in single-molecule experiments to isolate and tether RNAs, proteins, enzymes and ribozymes, amongst other biomolecules, between surface-modified beads for nanomechanical investigations. Custom DNA handles with varying lengths and chemical end-modifications are readily and reliably synthesized en masse, enabling force spectroscopic measurements with well-defined and long-lasting mechanical characteristics under physiological conditions over a large range of applied forces. Although these chemically tagged DNA handles are widely used, their further individual modification with protein receptors is less common and would allow for additional flexibility in grabbing biomolecules for mechanical measurements. In-depth information on reliable protocols for the synthesis of these DNA–protein hybrids and on their mechanical characteristics under varying physiological conditions are lacking in literature. Here, optical tweezers are used to investigate different protein-labelled DNA handles in a microfluidic environment under different physiological conditions. Digoxigenin (DIG-dsDNA-biotin handles of varying sizes (1000, 3034 and 4056 bp were conjugated with streptavidin or neutravidin proteins. The DIG-modified ends of these hybrids were bound to surface-modified polystyrene (anti-DIG beads. Using different physiological buffers, optical force measurements showed consistent mechanical characteristics with long dissociation times. These protein-modified DNA hybrids were also interconnected in situ with other tethered biotinylated DNA molecules. Electron-multiplying CCD (EMCCD imaging control experiments revealed that quantum dot–streptavidin conjugates at the end of DNA handles remain freely accessible. The experiments presented here demonstrate that handles produced with our protein–DNA labelling procedure are excellent candidates for grasping single molecules exposing tags suitable for molecular

Mechanical properties of hydroxyapatite single crystals from nanoindentation data

Science.gov (United States)

Zamiri, A.; De, S.

2011-01-01

In this paper we compute elasto-plastic properties of hydroxyapatite single crystals from nanindentation data using a two-step algorithm. In the first step the yield stress is obtained using hardness and Young’s modulus data, followed by the computation of the flow parameters. The computational approach is first validated with data from existing literature. It is observed that hydroxyapatite single crystals exhibit anisotropic mechanical response with a lower yield stress along the [1010] crystallographic direction compared to the [0001] direction. Both work hardening rate and work hardening exponent are found to be higher for indentation along the [0001] crystallographic direction. The stress-strain curves extracted here could be used for developing constitutive models for hydroxyapatite single crystals. PMID:21262492

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

Science.gov (United States)

Albanna, Mohammad Zaki

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

Protein interactions at the heart of cardiac chamber formation

NARCIS (Netherlands)

Boogerd, Cornelis J. J.; Moorman, Antoon F. M.; Barnett, Phil

2009-01-01

The vertebrate heart is a muscular pump that contracts in a rhythmic fashion to propel the blood through the body. During evolution, the morphologically complex four-chambered heart of birds and mammals has evolved from a single-layered tube with peristaltic contractility. The heart of Drosophila,

Biomedical engineering support. Annual progress report, August 15, 1974--August 14, 1975. [/sup 238/PuO/sub 2/-powered mechanical heart

Energy Technology Data Exchange (ETDEWEB)

Kolff, W.J.; Smith, L.M.; Sandquist, G.M.

1975-01-01

The major responsibility of the Institute for Biomedical Engineering at the University of Utah under the ERDA Artificial Heart Program has been to provide in vitro and in vivo experimental data and evaluation of the anatomical fitting, accommodation, performance and adequacy of the artificial heart system and its components as they are developed in the ERDA Program and provided to the Institute for study. The Institute also has the responsibility of designing, constructing and testing the blood handling components of the Blood Pump and insuring reliability, durability and satisfactory performance of these system components. During the reporting period, nine total heart replacement experiments were performed in calves using the ERDA Blood Pump powered by an electric motor implanted in the abdomen. Results of the experiments are given. Ultimately the mechanical heart will be powered by a radioisotope heat source. (TFD)

Hydro-mechanical foundation for blood swirling vortex flows formation in the cardio-vascular system and the problem of artificial heart creation

Directory of Open Access Journals (Sweden)

Sergey G. Chefranov

2013-11-01

Full Text Available Leonardo da Vinci perhaps was the first who paid attention to the energetic efficiency of existence of vortices emerging near sines of Valsalva and defining normal functioning (opening of aortal valve. However up to now a fundamental problem of defining of mechanisms of mysterious energetic efficiency of functioning of cardio-vascular system (CVS of blood feeding of the organism is still remaining significantly not solved and this is, for example, one of the main restriction for the creation of artificial heart and corresponding valve systems. In the present paper, results witnessing possible important role of the very hydro-mechanical mechanism in the realization of the noted energetic efficiency of CVS due to formation in the CVS of spiral structural organization of the arterial blood flow observed by methods of MRT and color Doppler-measuring in the left ventricular of the heart and in aorta.

Heart Transplantation in Congenital Heart Disease: In Whom to Consider and When?

Science.gov (United States)

Attenhofer Jost, Christine H.; Schmidt, Dörthe; Huebler, Michael; Balmer, Christian; Noll, Georg; Caduff, Rosmarie; Greutmann, Matthias

2013-01-01

Due to impressive improvements in surgical repair options, even patients with complex congenital heart disease (CHD) may survive into adulthood and have a high risk of end-stage heart failure. Thus, the number of patients with CHD needing heart transplantation (HTx) has been increasing in the last decades. This paper summarizes the changing etiology of causes of death in heart failure in CHD. The main reasons, contraindications, and risks of heart transplantation in CHD are discussed and underlined with three case vignettes. Compared to HTx in acquired heart disease, HTx in CHD has an increased risk of perioperative death and rejection. However, outcome of HTx for complex CHD has improved over the past 20 years. Additionally, mechanical support options might decrease the waiting list mortality in the future. The number of patients needing heart-lung transplantation (especially for Eisenmenger's syndrome) has decreased in the last years. Lung transplantation with intracardiac repair of a cardiac defect is another possibility especially for patients with interatrial shunts. Overall, HTx will remain an important treatment option for CHD in the near future. PMID:23577237

Exercise Intolerance in Heart Failure

DEFF Research Database (Denmark)

Brassard, Patrice; Gustafsson, Finn

2016-01-01

Exercise tolerance is affected in patients with heart failure (HF). Although the inability of the heart to pump blood to the working muscle has been the conventional mechanism proposed to explain the lowered capacity of patients with HF to exercise, evidence suggests that the pathophysiological...

Hyperthyroidism and the Heart.

Science.gov (United States)

Osuna, Patricia Mejia; Udovcic, Maja; Sharma, Morali D

2017-01-01

Thyroid hormones have a significant impact on cardiac function and structure. Excess thyroid hormone affects cardiovascular hemodynamics, leading to high-output heart failure and, in late stages, dilated cardiomyopathy. In this review, we discuss how hyperthyroidism affects cardiovascular pathophysiology and molecular mechanisms and examine the complications caused by excess thyroid hormone, such as heart failure and atrial fibrillation.

Methods of estimation of mitral valve regurgitation for the cardiac surgeon

Directory of Open Access Journals (Sweden)

Baikoussis Nikolaos G

2009-07-01

Full Text Available Abstract Mitral valve regurgitation is a relatively common and important heart valve lesion in clinical practice and adequate assessment is fundamental to decision on management, repair or replacement. Disease localised to the posterior mitral valve leaflet or focal involvement of the anterior mitral valve leaflet is most amenable to mitral valve repair, whereas patients with extensive involvement of the anterior leaflet or incomplete closure of the valve are more suitable for valve replacement. Echocardiography is the recognized investigation of choice for heart valve disease evaluation and assessment. However, the technique is depended on operator experience and on patient's hemodynamic profile, and may not always give optimal diagnostic views of mitral valve dysfunction. Cardiac catheterization is related to common complications of an interventional procedure and needs a hemodynamic laboratory. Cardiac magnetic resonance (MRI seems to be a useful tool which gives details about mitral valve anatomy, precise point of valve damage, as well as the quantity of regurgitation. Finally, despite of its higher cost, cardiac MRI using cine images with optimized spatial and temporal resolution can also resolve mitral valve leaflet structural motion, and can reliably estimate the grade of regurgitation.

Calculation of lung-heart ratios for single-photon emission computed tomography

International Nuclear Information System (INIS)

Soares, E.J.; King, M.A.; Glick, S.J.; Villegas, B.J.

1996-01-01

The authors investigate the effectiveness of simple iterative reconstruction techniques in calculating lung-heart activity ratios (LHRs). The LHR has been shown to be an effective indicator of the severity of coronary artery disease in cardiac SPECT. A study was conducted with a mathematical cardiac torso phantom that modelled uptake of 201 Tl in the heart and lung regions. The projection data included only the effects of nonuniform photon attenuation. The data were first reconstructed with zeroth-order Chang and a variant of the Bellini method, both of which utilize information from the nonuniform attenuation map. This nonuniform (NU) Bellini method compensates exactly for attenuation in the heart region, but is incorrect for other regions in the medium. These reconstructions were then used as the initial estimates in the iterative Chang, variable step-size (VSS) Chang, and Morozumi methods,m for one and five iterations. The average heart count (AHC) and average lung count (ALC) were calculated using region-of-interest (ROI) templates derived from the true activity map. The population mean LHR was tabulated as the ratio of the ALC to AHC. Using the same reconstruction procedure, the authors also calculated the sample mean LHR and standard deviation from 21 noisy 3D reconstructions

Nuclear cardiology and heart failure

International Nuclear Information System (INIS)

Giubbini, Raffaele; Bertagna, Francesco; Milan, Elisa; Mut, Fernando; Dondi, Maurizio; Metra, Marco; Rodella, Carlo

2009-01-01

The prevalence of heart failure in the adult population is increasing. It varies between 1% and 2%, although it mainly affects elderly people (6-10% of people over the age of 65 years will develop heart failure). The syndrome of heart failure arises as a consequence of an abnormality in cardiac structure, function, rhythm, or conduction. Coronary artery disease is the leading cause of heart failure and it accounts for this disorder in 60-70% of all patients affected. Nuclear techniques provide unique information on left ventricular function and perfusion by gated-single photon emission tomography (SPECT). Myocardial viability can be assessed by both SPECT and PET imaging. Finally, autonomic dysfunction has been shown to increase the risk of death in patients with heart disease and this may be applicable to all patients with cardiac disease regardless of aetiology. MIBG scanning has a very promising prognostic value in patients with heart failure. (orig.)

Nuclear cardiology and heart failure

Energy Technology Data Exchange (ETDEWEB)

Giubbini, Raffaele; Bertagna, Francesco [University of Brescia, Department of Nuclear Medicine, Brescia (Italy); Milan, Elisa [Ospedale Di Castelfranco Veneto, Nuclear Medicine Unit, Castelfranco Veneto (Italy); Mut, Fernando; Dondi, Maurizio [International Atomic Energy Agency, Nuclear Medicine Section, Division of Human Health, Vienna (Austria); Metra, Marco [University of Brescia, Department of Cardiology, Brescia (Italy); Rodella, Carlo [Health Physics Department, Spedali Civili di Brescia, Brescia (Italy)

2009-12-15

The prevalence of heart failure in the adult population is increasing. It varies between 1% and 2%, although it mainly affects elderly people (6-10% of people over the age of 65 years will develop heart failure). The syndrome of heart failure arises as a consequence of an abnormality in cardiac structure, function, rhythm, or conduction. Coronary artery disease is the leading cause of heart failure and it accounts for this disorder in 60-70% of all patients affected. Nuclear techniques provide unique information on left ventricular function and perfusion by gated-single photon emission tomography (SPECT). Myocardial viability can be assessed by both SPECT and PET imaging. Finally, autonomic dysfunction has been shown to increase the risk of death in patients with heart disease and this may be applicable to all patients with cardiac disease regardless of aetiology. MIBG scanning has a very promising prognostic value in patients with heart failure. (orig.)

Cell migration during heart regeneration in zebrafish.

Science.gov (United States)

Tahara, Naoyuki; Brush, Michael; Kawakami, Yasuhiko

2016-07-01

Zebrafish possess the remarkable ability to regenerate injured hearts as adults, which contrasts the very limited ability in mammals. Although very limited, mammalian hearts do in fact have measurable levels of cardiomyocyte regeneration. Therefore, elucidating mechanisms of zebrafish heart regeneration would provide information of naturally occurring regeneration to potentially apply to mammalian studies, in addition to addressing this biologically interesting phenomenon in itself. Studies over the past 13 years have identified processes and mechanisms of heart regeneration in zebrafish. After heart injury, pre-existing cardiomyocytes dedifferentiate, enter the cell cycle, and repair the injured myocardium. This process requires interaction with epicardial cells, endocardial cells, and vascular endothelial cells. Epicardial cells envelope the heart, while endocardial cells make up the inner lining of the heart. They provide paracrine signals to cardiomyocytes to regenerate the injured myocardium, which is vascularized during heart regeneration. In addition, accumulating results suggest that local migration of these major cardiac cell types have roles in heart regeneration. In this review, we summarize the characteristics of various heart injury methods used in the research community and regeneration of the major cardiac cell types. Then, we discuss local migration of these cardiac cell types and immune cells during heart regeneration. Developmental Dynamics 245:774-787, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Connection forms for beating the heart

DEFF Research Database (Denmark)

Mensch, Arthur; Piuze, Emmanuel; Lehnert, Lucas

2014-01-01

We combine recent work on modeling cardiac mechanics using a finite volume method with the insight that heart wall myofiber orientations exhibit a particular volumetric geometry. In our finite vol- ume mechanical simulation we use Maurer-Cartan one-forms to add a geometrical consistency term...... to control the rate at which myofiber ori- entation changes in the direction perpendicular to the heart wall. This allows us to estimate material properties related to both the passive and active parameters in our model. We have obtained preliminary results on the 4 canine datasets of the 2014 mechanics...... challenge using the FEBio software suite. In ongoing work we are validating and improving the model using rat heart (ex-vivo DTI and in-vivo tagging) MRI datasets, from which we have estimated strain tensors....

Comprehension and acceptability of a patient information leaflet (pil for antiretroviral therapy

Directory of Open Access Journals (Sweden)

Betty Mwingira

2006-11-01

Full Text Available The patient information leaflet (PIL is recognised as playing a key role in informing patients about their medicines. The objectives of this research were to evaluate the readability and understanding of a PIL for the first-line ARV (antiretroviral regimen available in the South African public health sector, and investigate its acceptability in the target Xhosa population. Opsomming Daar word algemeen aanvaar dat die pasiëntinligtingsblaadjie (PIB ‘n sleutelrol speel in die oordra van inligting ten opsigte van medikasie aan pasiënte. Die doelwitte van hierdie navorsing was om die leesbaarheid en begrip van ‘n PIB vir die eerste-linie antiretrovirale (ARV regimen wat in die Suid-Afrikaanse openbare gesondheidsektor beskikbaar is, te evalueer, en om die aanvaarbaarheid daarvan in ‘n teiken-Xhosabevolking te ondersoek. *Please note: This is a reduced version of the abstract. Please refer to PDF for full text.

Single-walled carbon nanotubes based chemiresistive genosensor for label-free detection of human rheumatic heart disease

Science.gov (United States)

Singh, Swati; Kumar, Ashok; Khare, Shashi; Mulchandani, Ashok; Rajesh

2014-11-01

A specific and ultrasensitive, label free single-walled carbon nanotubes (SWNTs) based chemiresistive genosensor was fabricated for the early detection of Streptococcus pyogenes infection in human causing rheumatic heart disease. The mga gene of S. pyogenes specific 24 mer ssDNA probe was covalently immobilized on SWNT through a molecular bilinker, 1-pyrenemethylamine, using carbodiimide coupling reaction. The sensor was characterized by the current-voltage (I-V) characteristic curve and scanning electron microscopy. The sensing performance of the sensor was studied with respect to changes in conductance in SWNT channel based on hybridization of the target S. pyogenes single stranded genomic DNA (ssG-DNA) to its complementary 24 mer ssDNA probe. The sensor shows negligible response to non-complementary Staphylococcus aureus ssG-DNA, confirming the specificity of the sensor only with S. pyogenes. The genosensor exhibited a linear response to S. pyogenes G-DNA from 1 to1000 ng ml-1 with a limit of detection of 0.16 ng ml-1.

A new approach of quantum mechanics for neutron single-slit diffraction

International Nuclear Information System (INIS)

Wu Xiangyao; Yang Jinghai; Liu Xiaojing; Wang Li; Liu Bing; Fan Xihui; Guo Yiqing

2007-01-01

Phenomena of electron, neutron, atomic and molecular diffraction have been studied in many experiments, and these experiments are explained by many theoretical works. We study neutron single-slit diffraction with a quantum mechanical approach. It is found that the obvious diffraction patterns can be obtained when the single slit width a is in the range of 3λ-60λ. We also find a new quantum effect of the thickness of single-slit which can make a large impact on the diffraction pattern. The new quantum effect predicted in our work can be tested by the neutron single-slit diffraction experiment. (authors)

Quasi free mechanism in single photon double ionization of helium

Energy Technology Data Exchange (ETDEWEB)

Schoeffler, Markus; Stuck, Christian [Frankfurt Univ., Frankfurt am Main (Germany). Inst. fuer Kernphysik; Lawrence Berkeley National Lab, Berkeley, CA (United States); Jahnke, Till; Waitz, Markus; Trinter, Florian; Lenz, Ute; Schmidt-Boecking, Horst; Doerner, Reinhard [Frankfurt Univ., Frankfurt am Main (Germany). Inst. fuer Kernphysik; Jones, Mathew; Landers, Allen [Auburn University, Auburn, AL (United States); Belkacem, Ali; Weber, Thorsten [Lawrence Berkeley National Lab, Berkeley, CA (United States); Cocke, Lew [Kansas State University, Manhattan, KS (United States)

2012-07-01

Double ionization of Helium by a single photon is widely believed to proceed through two mechanisms: knock-off (TS1) or shake-off, with the last one dominating at high photon energies. A new mechanism, termed ''Quasi Free Mechanism'' (QFM) was predicted 35 years ago by Amusia and coworkers, but escaped experimental observation till today. Here we provide the first proof of this mechanism using 800 eV photons from the Advanced Light Source. Fragments (electrons and ions) were measured in coincidence using momentum spectroscopy (COLTRIMS). He{sup (}2+) ions with zero momentum were found - the fingerprint for the QFM.

System overview of the fully implantable destination therapy--ReinHeart-total artificial heart.

Science.gov (United States)

Pelletier, Benedikt; Spiliopoulos, Sotirios; Finocchiaro, Thomas; Graef, Felix; Kuipers, Kristin; Laumen, Marco; Guersoy, Dilek; Steinseifer, Ulrich; Koerfer, Reiner; Tenderich, Gero

2015-01-01

Owing to the lack of suitable allografts, the demand for long-term mechanical circulatory support in patients with biventricular end-stage heart failure is rising. Currently available Total Artificial Heart (TAH) systems consist of pump units with only limited durability, percutaneous tubes and bulky external equipment that limit the quality of life. Therefore we are focusing on the development of a fully implantable, highly durable destination therapy total artificial heart. The ReinHeart-TAH system consists of a passively filling pump unit driven by a low-wear linear drive between two artificial ventricles, an implantable control unit and a compliance chamber. The TAH is powered by a transcutaneous energy transmission system. The flow distribution inside the ventricles was analysed by fluid structure interaction simulation and particle image velocimetry measurements. Along with durability tests, the hydrodynamic performance and flow balance capability were evaluated in a mock circulation loop. Animal trials are ongoing. Based on fluid structure interaction simulation and particle image velocimetry, blood stagnation areas have been significantly reduced. In the mock circulation loop the ReinHeart-TAH generated a cardiac output of 5 l/min at an operating frequency of 120 bpm and an aortic pressure of 120/80 mmHg. The highly effective preload sensitivity of the passively filling ventricles allowed the sensorless integration of the Frank Starling mechanism. The ReinHeart-TAH effectively replaced the native heart's function in animals for up to 2 days. In vitro and in vivo testing showed a safe and effective function of the ReinHeart-TAH system. This has the potential to become an alternative to transplantation. However, before a first-in-man implant, chronic animal trials still have to be completed. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Evaluation of myocardial sympathetic nerve function in patients with mitral valve prolapse using iodine-123-metaiodobenzylguanidine myocardial scintigraphy

International Nuclear Information System (INIS)

Kishi, Fumiko; Nomura, Masahiro; Yukinaka, Michiko

1996-01-01

Mitral valve prolapse (MVP) is closely related to myocardial sympathetic nerve function. This study evaluated the presence of impaired myocardial sympathetic nerve function by Iodine-123-metaiodobenzylguanidine (MIBG) scintigraphy in nine patients with MVP. For comparison, 15 healthy subjects without heart disease were investigated (control group). Single photon emission computed tomography (SPECT) and anterior planar myocardial scintigraphy were performed 15 min (initial images) and 3 hours (delayed images) after injection of MIBG (111 MBq). The location and degrees of reduced tracer uptake were evaluated. Myocardial MIBG uptake was quantified by uptake ratio of the heart (H) to upper mediastinum (M) on the anterior planar images (H/M). Percentage washout of MIBG in nine sectors of all oblique slices along the short-axis was calculated. The washout rates were higher at the inferoposterior and septal segments in patients with anterior leaflet prolapse, and at inferoposterior and lateral segments in patients with posterior leaflet prolapse. The bull's eye map showed increased washout rate in the apical and posteroseptal basal segments. There was no significant difference in the H/M ratio between MVP patients and the control group. These results indicate that MIBG can be used to evaluate localized myocardial sympathetic nerve function in MVP. (author)

Mechanics of single-walled carbon nanotubes inside open single-walled carbon nanocones

International Nuclear Information System (INIS)

Ansari, R.; Hosseinzadeh, M.

2013-01-01

This study investigates the mechanical characteristics of single-walled carbon nanotubes (CNTs) inside open single-walled carbon nanocones (CNCs). New semi-analytical expressions are presented to evaluate van der Waals (vdW) interactions between CNTs and open CNCs. Continuum approximation, along with the the Lennard-Jones (LJ) potential function, is used in this study. The effects of geometrical parameters on alterations in vdW potential energy and the interaction force are extensively examined for the concentric CNT-open CNC configuration. The CNT is assumed to enter the nanocone either through the small end or the wide end of the cone. The preferred position of the CNT with respect to the nanocone axis is fully investigated for various geometrical parameters. The optimum nanotube radius minimizing the total potential energy of the concentric configuration is determined for different radii of the small end of the cone. The examined configuration generates asymmetric oscillation; thus, the system constitutes a nano-oscillator.

Vitamin D Biology in Heart Failure : Molecular Mechanisms and Systematic Review

NARCIS (Netherlands)

Meems, Laura M. G.; van der Harst, P.; van Gilst, W. H.; de Boer, R. A.

Vitamin D has recently been suggested as an important mediator of blood pressure and cardiovascular disease, including heart failure. In patients with heart failure, low vitamin D levels are associated with adverse outcome and correlate with established clinical correlates and biomarkers. Many

[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.

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.

Load dependency in force-length relations in isolated single cardiomyocytes.

Science.gov (United States)

Iribe, Gentaro; Kaneko, Toshiyuki; Yamaguchi, Yohei; Naruse, Keiji

2014-08-01

The previously reported pressure-volume (PV) relationship in frog hearts shows that end-systolic PV relation (ESPVR) is load dependent, whereas ESPVR in canine hearts is load independent. To study intrinsic cardiac mechanics in detail, it is desirable to study mechanics in a single isolated cardiomyocyte that is free from interstitial connective tissue. Previous single cell mechanics studies used a pair of carbon fibers (CF) attached to the upper surface of opposite cell ends to stretch cells. These studies showed that end-systolic force-length (FL) relation (ESFLR) is load independent. However, the range of applicable mechanical load using the conventional technique is limited because of weak cell-CF attachment. Therefore, the behavior of ESFLR in single cells under physiologically possible conditions of greater load is not yet well known. To cover wider loading range, we contrived a new method to hold cell-ends more firmly using two pairs of CF attached to both upper and bottom surfaces of cells. The new method allowed stretching cells to 2.2 μm or more in end-diastolic sarcomere length. ESFLR virtually behaves in a load independent manner only with end-diastolic sarcomere length less than 1.95 μm. It exhibited clear load dependency with higher preload, especially with low afterload conditions. Instantaneous cellular elastance curves showed that decreasing afterload enhanced relaxation and slowed time to peak elastance, as previously reported. A simulation study of a mathematical model with detailed description of thin filament activation suggested that velocity dependent thin filament inactivation is crucial for the observed load dependent behaviors and previously reported afterload dependent change in Ca(2+) transient shape. Copyright © 2014 Elsevier Ltd. All rights reserved.

Construct validity of the Heart Failure Screening Tool (Heart-FaST) to identify heart failure patients at risk of poor self-care: Rasch analysis.

Science.gov (United States)

Reynolds, Nicholas A; Ski, Chantal F; McEvedy, Samantha M; Thompson, David R; Cameron, Jan

2018-02-14

The aim of this study was to psychometrically evaluate the Heart Failure Screening Tool (Heart-FaST) via: (1) examination of internal construct validity; (2) testing of scale function in accordance with design; and (3) recommendation for change/s, if items are not well adjusted, to improve psychometric credential. Self-care is vital to the management of heart failure. The Heart-FaST may provide a prospective assessment of risk, regarding the likelihood that patients with heart failure will engage in self-care. Psychometric validation of the Heart-FaST using Rasch analysis. The Heart-FaST was administered to 135 patients (median age = 68, IQR = 59-78 years; 105 males) enrolled in a multidisciplinary heart failure management program. The Heart-FaST is a nurse-administered tool for screening patients with HF at risk of poor self-care. A Rasch analysis of responses was conducted which tested data against Rasch model expectations, including whether items serve as unbiased, non-redundant indicators of risk and measure a single construct and that rating scales operate as intended. The results showed that data met Rasch model expectations after rescoring or deleting items due to poor discrimination, disordered thresholds, differential item functioning, or response dependence. There was no evidence of multidimensionality which supports the use of total scores from Heart-FaST as indicators of risk. Aggregate scores from this modified screening tool rank heart failure patients according to their "risk of poor self-care" demonstrating that the Heart-FaST items constitute a meaningful scale to identify heart failure patients at risk of poor engagement in heart failure self-care. © 2018 John Wiley & Sons Ltd.

Operation analysis of a Chebyshev-Pantograph leg mechanism for a single DOF biped robot

Science.gov (United States)

Liang, Conghui; Ceccarelli, Marco; Takeda, Yukio

2012-12-01

In this paper, operation analysis of a Chebyshev-Pantograph leg mechanism is presented for a single degree of freedom (DOF) biped robot. The proposed leg mechanism is composed of a Chebyshev four-bar linkage and a pantograph mechanism. In contrast to general fully actuated anthropomorphic leg mechanisms, the proposed leg mechanism has peculiar features like compactness, low-cost, and easy-operation. Kinematic equations of the proposed leg mechanism are formulated for a computer oriented simulation. Simulation results show the operation performance of the proposed leg mechanism with suitable characteristics. A parametric study has been carried out to evaluate the operation performance as function of design parameters. A prototype of a single DOF biped robot equipped with two proposed leg mechanisms has been built at LARM (Laboratory of Robotics and Mechatronics). Experimental test shows practical feasible walking ability of the prototype, as well as drawbacks are discussed for the mechanical design.

Advanced Prop-fan Engine Technology (APET) single- and counter-rotation gearbox/pitch change mechanism

Science.gov (United States)

Reynolds, C. N.

1985-01-01

The preliminary design of advanced technology (1992) turboprop engines for single-rotation prop-fans and conceptual designs of pitch change mechanisms for single- and counter-rotation prop-fan application are discussed. The single-rotation gearbox is a split path, in-line configuration. The counter-rotation gearbox is an in-line, differential planetary design. The pitch change mechanisms for both the single- and counter-rotation arrangements are rotary/hydraulic. The advanced technology single-rotation gearbox yields a 2.4 percent improvement in aircraft fuel burn and a one percent improvement in operating cost relative to a current technology gearbox. The 1992 counter-rotation gearbox is 15 percent lighter, 15 percent more reliable, 5 percent lower in cost, and 45 percent lower in maintenance cost than the 1992 single-rotation gearbox. The pitch controls are modular, accessible, and external.

Influence of alloy elements on physical and mechanical properties of single crystalline austenitic stainless steels

International Nuclear Information System (INIS)

Okamoto, Kazutaka; Kaneda, Junya; Yoshinari, Akira; Aono, Yasuhisa

2000-01-01

The single crystalline austenitic stainless steels based on 316 L were developed to improve their resistance to intergranular corrosion and stress corrosion cracking. However the mechanical properties of the single crystals were lower than those of polycrystalline. The precipitation hardening methods were applied to the single crystal for the increase of their mechanical strength by addition of niobium and heat treatments. In this paper, the influences of niobium concentration on the several physical and mechanical properties of these single crystalline austenitic stainless steels were studied. The thermal conductivity, coefficients of thermal expansion and elastic constants of the single crystals were almost the same as those of polycrystalline independently of the niobium concentration. The mechanical properties of the single crystals strongly depended on the niobium concentration and the orientation. In the specimen which contains 1.0 mass% niobium, 0.2% proof stress were remarkably improved; 370 MPa, 337 MPa and 403 MPa were obtained in , and orientations at the room temperature. The creep rupture strength and the high cycle fatigue strength were also improved by addition of niobium. In the -orientated specimen which contains 1.0 mass% niobium, the creep rupture strength at 873 K for 103 hours, 245 MPa and the high cycle fatigue strength at 773 K for 107 cycles, 220 MPa were obtained. Furthermore, the single crystalline pipe, bolts and nuts were successfully manufactured for the application of these single crystals. (author)

Pulmonary Catherization Data Correlate Poorly with Renal Function in Heart Failure.

Science.gov (United States)

Masha, Luke; Stone, James; Stone, Danielle; Zhang, Jun; Sheng, Luo

2018-04-10

The mechanisms of renal dysfunction in heart failure are poorly understood. We chose to explore the relationship of cardiac filling pressures and cardiac index (CI) in relation to renal dysfunction in advanced heart failure. To determine the relationship between renal function and cardiac filling pressures using the United Network of Organ Sharing (UNOS) pulmonary artery catherization registry. Patients over the age of 18 years who were listed for single-organ heart transplantation were included. Exclusion criteria included a history of mechanical circulatory support, previous transplantation, any use of renal replacement therapy, prior history of malignancy, and cardiac surgery, amongst others. Correlations between serum creatinine (SCr) and CI, pulmonary capillary wedge pressure (PCWP), pulmonary artery systolic pressure (PASP), and pulmonary artery diastolic pressure (PADP) were assessed by Pearson correlation coefficients and simple linear regression coefficients. Pearson correlation coefficients between SCr and PCWP, PASP, and PADP were near zero with values of 0.1, 0.07, and 0.08, respectively (p < 0.0001). A weak negative correlation coefficient between SCr and CI was found (correlation coefficient, -0.045, p = 0.027). In a subgroup of young patients unlikely to have noncardiac etiologies, no significant correlations between these values were identified. These findings suggest that, as assessed by pulmonary artery catherization, none of the factors - PCWP, PASP, PADP, or CI - play a prominent role in cardiorenal syndromes. © 2018 S. Karger AG, Basel.

Using routinely collected data to evaluate a leaflet campaign to increase the presentation of people with memory problems to general practice: a locality based controlled study

Directory of Open Access Journals (Sweden)

Tom Chan

2010-09-01

Conclusions During a leaflet campaign the recording and management ofmemory problems increased. However, there was greater improvement in the control locality. This study demonstrates the importance of including a control group and the strengths of routine primary care data.

Load-dependent extracellular matrix organization in atrioventricular heart valves: differences and similarities.

Science.gov (United States)

Alavi, S Hamed; Sinha, Aditi; Steward, Earl; Milliken, Jeffrey C; Kheradvar, Arash

2015-07-15

The extracellular matrix of the atrioventricular (AV) valves' leaflets has a key role in the ability of these valves to properly remodel in response to constantly varying physiological loads. While the loading on mitral and tricuspid valves is significantly different, no information is available on how collagen fibers change their orientation in response to these loads. This study delineates the effect of physiological loading on AV valves' leaflets microstructures using Second Harmonic Generation (SHG) microscopy. Fresh natural porcine tricuspid and mitral valves' leaflets (n = 12/valve type) were cut and prepared for the experiments. Histology and immunohistochemistry were performed to compare the microstructural differences between the valves. The specimens were imaged live during the relaxed, loading, and unloading phases using SHG microscopy. The images were analyzed with Fourier decomposition to mathematically seek changes in collagen fiber orientation. Despite the similarities in both AV valves as seen in the histology and immunohistochemistry data, the microstructural arrangement, especially the collagen fiber distribution and orientation in the stress-free condition, were found to be different. Uniaxial loading was dependent on the arrangement of the fibers in their relaxed mode, which led the fibers to reorient in-line with the load throughout the depth of the mitral leaflet but only to reorient in-line with the load in deeper layers of the tricuspid leaflet. Biaxial loading arranged the fibers in between the two principal axes of the stresses independently from their relaxed states. Unlike previous findings, this study concludes that the AV valves' three-dimensional extracellular fiber arrangement is significantly different in their stress-free and uniaxially loaded states; however, fiber rearrangement in response to the biaxial loading remains similar. Copyright © 2015 the American Physiological Society.

Double-slit experiment with single wave-driven particles and its relation to quantum mechanics.

Science.gov (United States)

Andersen, Anders; Madsen, Jacob; Reichelt, Christian; Rosenlund Ahl, Sonja; Lautrup, Benny; Ellegaard, Clive; Levinsen, Mogens T; Bohr, Tomas

2015-07-01

In a thought-provoking paper, Couder and Fort [Phys. Rev. Lett. 97, 154101 (2006)] describe a version of the famous double-slit experiment performed with droplets bouncing on a vertically vibrated fluid surface. In the experiment, an interference pattern in the single-particle statistics is found even though it is possible to determine unambiguously which slit the walking droplet passes. Here we argue, however, that the single-particle statistics in such an experiment will be fundamentally different from the single-particle statistics of quantum mechanics. Quantum mechanical interference takes place between different classical paths with precise amplitude and phase relations. In the double-slit experiment with walking droplets, these relations are lost since one of the paths is singled out by the droplet. To support our conclusions, we have carried out our own double-slit experiment, and our results, in particular the long and variable slit passage times of the droplets, cast strong doubt on the feasibility of the interference claimed by Couder and Fort. To understand theoretically the limitations of wave-driven particle systems as analogs to quantum mechanics, we introduce a Schrödinger equation with a source term originating from a localized particle that generates a wave while being simultaneously guided by it. We show that the ensuing particle-wave dynamics can capture some characteristics of quantum mechanics such as orbital quantization. However, the particle-wave dynamics can not reproduce quantum mechanics in general, and we show that the single-particle statistics for our model in a double-slit experiment with an additional splitter plate differs qualitatively from that of quantum mechanics.

Double-slit experiment with single wave-driven particles and its relation to quantum mechanics

Science.gov (United States)

Andersen, Anders; Madsen, Jacob; Reichelt, Christian; Rosenlund Ahl, Sonja; Lautrup, Benny; Ellegaard, Clive; Levinsen, Mogens T.; Bohr, Tomas

2015-07-01

In a thought-provoking paper, Couder and Fort [Phys. Rev. Lett. 97, 154101 (2006), 10.1103/PhysRevLett.97.154101] describe a version of the famous double-slit experiment performed with droplets bouncing on a vertically vibrated fluid surface. In the experiment, an interference pattern in the single-particle statistics is found even though it is possible to determine unambiguously which slit the walking droplet passes. Here we argue, however, that the single-particle statistics in such an experiment will be fundamentally different from the single-particle statistics of quantum mechanics. Quantum mechanical interference takes place between different classical paths with precise amplitude and phase relations. In the double-slit experiment with walking droplets, these relations are lost since one of the paths is singled out by the droplet. To support our conclusions, we have carried out our own double-slit experiment, and our results, in particular the long and variable slit passage times of the droplets, cast strong doubt on the feasibility of the interference claimed by Couder and Fort. To understand theoretically the limitations of wave-driven particle systems as analogs to quantum mechanics, we introduce a Schrödinger equation with a source term originating from a localized particle that generates a wave while being simultaneously guided by it. We show that the ensuing particle-wave dynamics can capture some characteristics of quantum mechanics such as orbital quantization. However, the particle-wave dynamics can not reproduce quantum mechanics in general, and we show that the single-particle statistics for our model in a double-slit experiment with an additional splitter plate differs qualitatively from that of quantum mechanics.

Radiopharmaceuticals for diagnosis of ischemic heart disease

Energy Technology Data Exchange (ETDEWEB)

Komarek, P; Chalabala, M [Institut pro Dalsi Vzdelavani Lekaru a Farmaceutu, Prague (Czechoslovakia)

1982-01-01

Radiopharmaceuticals used for diagnosing ischemic heart disease in the experimental and clinical practice are reviewed. The mechanism of their retention by the heart muscle is briefly described. The respective radiopharmaceuticals are divided into preparations imaging disorders in the blood supply of the cardiac muscle, diagnosing the myocardial infarction, and evaluating the contractility of the heart.

Right ventricular strain in heart failure: Clinical perspective.

Science.gov (United States)

Tadic, Marijana; Pieske-Kraigher, Elisabeth; Cuspidi, Cesare; Morris, Daniel A; Burkhardt, Franziska; Baudisch, Ana; Haßfeld, Sabine; Tschöpe, Carsten; Pieske, Burket

2017-10-01

The number of studies demonstrating the importance of right ventricular remodelling in a wide range of cardiovascular diseases has increased in the past two decades. Speckle-tracking imaging provides new variables that give comprehensive information about right ventricular function and mechanics. In this review, we summarize current knowledge of right ventricular mechanics in heart failure with reduced ejection fraction and preserved ejection fraction. We searched PubMed, MEDLINE, Ovid and Embase databases for studies published from January 2000 to December 2016 in the English language using the following keywords: "right ventricle"; "strain"; "speckle tracking"; "heart failure with reduced ejection fraction"; and "heart failure with preserved ejection fraction". Investigations showed that right ventricular dysfunction is associated with higher cardiovascular and overall mortality in patients with heart failure, irrespective of ejection fraction. The number of studies investigating right ventricular strain in patients with heart failure with reduced ejection fraction is constantly increasing, whereas data on right ventricular mechanics in patients with heart failure with preserved ejection fraction are limited. Given the high feasibility, accuracy and clinical implications of right ventricular strain in the population with heart failure, it is of great importance to try to include the evaluation of right ventricular strain as a regular part of each echocardiographic examination in patients with heart failure. However, further investigations are necessary to establish right ventricular strain as a standard variable for decision-making. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Controlled switching of single-molecule junctions by mechanical motion of a phenyl ring

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Yuya Kitaguchi

2015-10-01

Full Text Available Mechanical methods for single-molecule control have potential for wide application in nanodevices and machines. Here we demonstrate the operation of a single-molecule switch made functional by the motion of a phenyl ring, analogous to the lever in a conventional toggle switch. The switch can be actuated by dual triggers, either by a voltage pulse or by displacement of the electrode, and electronic manipulation of the ring by chemical substitution enables rational control of the on-state conductance. Owing to its simple mechanics, structural robustness, and chemical accessibility, we propose that phenyl rings are promising components in mechanical molecular devices.

Results of open heart surgery in Jehovah's Witness patients. Single centre experience.

Science.gov (United States)

Juraszek, Andrzej; Kołsut, Piotr; Szymański, Jarosław; Kuriata, Jarosław; Kuśmierski, Krzysztof; Sitkowska-Rysiak, Ewa; Jasińska, Małgorzata; Kuśmierczyk, Mariusz

2017-09-01

Evaluation the results in patients from the religious community of Jehovah's Witness (JW) undergoing open heart surgery at our institution. Between September 2011 and March 2015, 21 patients with a religious background of the JW church underwent open heart surgery at our institution performed by the same surgical team. Mean age was 68.43 ±8.93 years. There were 13 (61.9%) female patients. Recombinant human erythropoietin was administered to every patient with a hemoglobin value open heart surgery in JW were very good, including combined procedures. The decrease of hematocrit serum levels significantly characterizing the postoperative period was highly acceptable in this series. Nevertheless, the number of sternum wound infections was a limiting factor for prompt postoperative recovery.

The Syncardia™ total artificial heart: in vivo, in vitro, and computational modeling studies

Science.gov (United States)

Slepian, Marvin J.; Alemu, Yared; Soares, João Silva; Smith, Richard G.; Einav, Shmuel; Bluestein, Danny

2014-01-01

) assessed of the degree of platelet reactivity induced by the present clinical 70 cc TAH using a closed loop platelet activity state assay, (2) modeled the motion of the TAH pulsatile mobile diaphragm, and (3) performed fluid-structure interactions and assessment of the flow behavior through inflow and outflow regions of the TAH fitted with modern bi-leaflet heart valves. Developing a range of TAH devices will afford biventricular replacement therapy to a wide range of patients, for both short and long-term therapy. PMID:23305813

Experimental evaluation of mechanical heart support system based on viscous friction disc pump

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A. M. Chernyavskiy

2017-01-01

Full Text Available Aim. Experimental evaluation of the viscous friction disk pump efficiency, studying the relationship between inter-disk clearance and sizes of input and output ports and pump performance parameters.Materials and methods. To assess the characteristics and to optimize the disk friction pump design the pump model and experimental stand were created. Pump dimensions were set on the basis of medical and biological requirements for mechanical heart support systems and with due consideration of the experimental studies of our colleagues from Pennsylvania. Flow volume of the working fluid was measured by float rotameter Krohne VA-40 with measurement error of not more than 1%. The pressure values in the hydrodynamic circuit were measured using a monitor manufactured by Biosoft-M. Expansion device allowed changing the flow resistance of the system simulating the total peripheral resistance of the circulatory system.Results. Linear direct correlation between the pump performance and the pressure drop of liquid being created at the inlet and outlet of the pump was obtained. The required flow rate (5–7 l/min and pressure (90–100 mmHg were reached when the rotor speed was in the range of 2500–3000 rev/min. It has been shown that the increase of the inlet diameter to 15 mm has not resulted in a significant increase in the pump performance, and that the highest efficiency values can be obtained for the magnitude of inter-disk gap of 0.4–0.5 mm.Conclusion. Designed and manufactured experimental disc pump model for pumping fluid has showed the fundamental possibility to use this model as a system for mechanical support of the heart.

Heart rate acceleration with GLP-1 receptor agonists in type 2 diabetes patients : an acute and 12-week randomised, double-blind, placebo-controlled trial

NARCIS (Netherlands)

Smits, Mark M; Tonneijck, Lennart; Muskiet, Marcel H A; Hoekstra, T.; Kramer, Mark H H; Diamant, Michaela; van Raalte, Daniël H

OBJECTIVE: To examine mechanisms underlying resting heart rate (RHR) increments of GLP-1 receptor agonists in type 2 diabetes patients. DESIGN: Acute and 12-week randomised, placebo-controlled, double-blind, single-centre, parallel-group trial. METHODS: In total, 57 type 2 diabetes patients

From developmental biology to heart repair

NARCIS (Netherlands)

Campione, M.; Moorman, A. F.; Kelly, R. G.

2007-01-01

Advances in our understanding of cardiac development have fuelled research into cellular approaches to myocardial repair of the damaged heart. In this collection of reviews we present recent advances into the basic mechanisms of heart development and the resident and non-resident progenitor cell

An in vitro investigation of the retrograde flow fields of two bileaflet mechanical heart valves.

Science.gov (United States)

Ellis, J T; Healy, T M; Fontaine, A A; Weston, M W; Jarret, C A; Saxena, R; Yoganathan, A P

1996-11-01

Fluid stresses occurring in retrograde flow fields during valve closure may play a significant role in thrombogenesis. The squeeze flow and regurgitant jets can cause damage to formed blood elements due to high levels of turbulent shear stress. The aim of this study was to characterize in detail the spatial structure and temporal behavior of the retrograde flow fields of the St. Jude Medical and Medtronic Parallel bileaflet mechanical heart valves. Three-component, coincident laser Doppler anemometry (LDA) velocity measurements were obtained facilitating the determination of the full Reynolds stress tensor and the principal stresses in the valve flow fields. The experiments were performed in the Georgia Tech aortic flow chamber under physiologic pulsatile flow conditions. Data were collected over several hundred cardiac cycles for subsequent phase window averaging and generation of mean velocity and turbulence statistics over 20 ms intervals. A region approximately 8 mm x 10 mm was mapped 1.0 mm upstream of one hinge of each valve with an incremental resolution of 0.13-0.25 mm. Animation of the data allowed the visualization of the flow fields and a quantitative display of mean velocity and turbulent stress values. In the St. Jude Medical squeeze flow, the peak turbulent shear stress was 800 dynes/cm2 and the peak reverse velocity was 0.60 m/s. In the Medtronic Parallel squeeze flow, the peak turbulent shear stress was 1,000 dynes/cm2 and the peak velocity 0.70 m/s. The leakage jet fields of the two valves were very different: in the case of the St. Jude Medical valve, turbulent shear stresses reached 1,800 dynes/cm2 and peak jet velocity was 0.80 m/s; in the case of the Medtronic Parallel valve, turbulent shear stresses reached 3,690 dynes/cm2 and the peak jet velocity was 1.9 m/s. The retrograde flow fields of these two bileaflet mechanical heart valves appear to be design-dependent. The elevated turbulent shear stresses generated by both valve designs may

Biomechanical regulation of in vitro cardiogenesis for tissue-engineered heart repair.

Science.gov (United States)

Zimmermann, Wolfram-Hubertus

2013-01-01

The heart is a continuously pumping organ with an average lifespan of eight decades. It develops from the onset of embryonic cardiogenesis under biomechanical load, performs optimally within a defined range of hemodynamic load, and fails if acutely or chronically overloaded. Unloading of the heart leads to defective cardiogenesis in utero, but can also lead to a desired therapeutic outcome (for example, in patients with heart failure under left ventricular assist device therapy). In light of the well-documented relevance of mechanical loading for cardiac physiology and pathology, it is plausible that tissue engineers have integrated mechanical stimulation regimens into protocols for heart muscle construction. To achieve optimal results, physiological principles of beat-to-beat myocardial loading and unloading should be simulated. In addition, heart muscle engineering, in particular if based on pluripotent stem cell-derived cardiomyocytes, may benefit from staggered tonic loading protocols to simulate viscoelastic properties of the prenatal and postnatal myocardial stroma. This review will provide an overview of heart muscle mechanics, summarize observations on the role of mechanical loading for heart development and postnatal performance, and discuss how physiological loading regimens can be exploited to advance myocardial tissue engineering towards a therapeutic application.

Binding energy and mechanical stability of single- and multi-walled carbon nanotube serpentines

International Nuclear Information System (INIS)

Zhao, Junhua; Lu, Lixin; Rabczuk, Timon

2014-01-01

Recently, Geblinger et al. [Nat. Nanotechnol. 3, 195 (2008)] and Machado et al. [Phys. Rev. Lett. 110, 105502 (2013)] reported the experimental and molecular dynamics realization of S-like shaped single-walled carbon nanotubes (CNTs), the so-called CNT serpentines. We reported here results from continuum modeling of the binding energy γ between different single- and multi-walled CNT serpentines and substrates as well as the mechanical stability of the CNT serpentine formation. The critical length for the mechanical stability and adhesion of different CNT serpentines are determined in dependence of E i I i , d, and γ, where E i I i and d are the CNT bending stiffness and distance of the CNT translation period. Our continuum model is validated by comparing its solution to full-atom molecular dynamics calculations. The derived analytical solutions are of great importance for understanding the interaction mechanism between different single- and multi-walled CNT serpentines and substrates

Single-walled carbon nanotubes based chemiresistive genosensor for label-free detection of human rheumatic heart disease

International Nuclear Information System (INIS)

Singh, Swati; Kumar, Ashok; Khare, Shashi; Mulchandani, Ashok; Rajesh

2014-01-01

A specific and ultrasensitive, label free single-walled carbon nanotubes (SWNTs) based chemiresistive genosensor was fabricated for the early detection of Streptococcus pyogenes infection in human causing rheumatic heart disease. The mga gene of S. pyogenes specific 24 mer ssDNA probe was covalently immobilized on SWNT through a molecular bilinker, 1-pyrenemethylamine, using carbodiimide coupling reaction. The sensor was characterized by the current-voltage (I-V) characteristic curve and scanning electron microscopy. The sensing performance of the sensor was studied with respect to changes in conductance in SWNT channel based on hybridization of the target S. pyogenes single stranded genomic DNA (ssG-DNA) to its complementary 24 mer ssDNA probe. The sensor shows negligible response to non-complementary Staphylococcus aureus ssG-DNA, confirming the specificity of the sensor only with S. pyogenes. The genosensor exhibited a linear response to S. pyogenes G-DNA from 1 to1000 ng ml −1 with a limit of detection of 0.16 ng ml −1

Single-walled carbon nanotubes based chemiresistive genosensor for label-free detection of human rheumatic heart disease

Energy Technology Data Exchange (ETDEWEB)

Singh, Swati; Kumar, Ashok, E-mail: rajesh-csir@yahoo.com, E-mail: ashokigib@rediffmail.com [CSIR-Institute of Genomics and Integrative Biology, Mall Road, Delhi 110007 (India); Academy of Scientific and Innovative Research (AcSIR), New Delhi (India); Khare, Shashi [National Centre for Disease Control, Sham Nath Marg, Delhi 110054 (India); Mulchandani, Ashok [Department of Chemical and Environmental Engineering, University of California, Riverside, California 92521 (United States); Rajesh, E-mail: rajesh-csir@yahoo.com, E-mail: ashokigib@rediffmail.com [CSIR-National Physical Laboratory, Dr. K. S. Krishnan Road, New Delhi 110012 (India)

2014-11-24

A specific and ultrasensitive, label free single-walled carbon nanotubes (SWNTs) based chemiresistive genosensor was fabricated for the early detection of Streptococcus pyogenes infection in human causing rheumatic heart disease. The mga gene of S. pyogenes specific 24 mer ssDNA probe was covalently immobilized on SWNT through a molecular bilinker, 1-pyrenemethylamine, using carbodiimide coupling reaction. The sensor was characterized by the current-voltage (I-V) characteristic curve and scanning electron microscopy. The sensing performance of the sensor was studied with respect to changes in conductance in SWNT channel based on hybridization of the target S. pyogenes single stranded genomic DNA (ssG-DNA) to its complementary 24 mer ssDNA probe. The sensor shows negligible response to non-complementary Staphylococcus aureus ssG-DNA, confirming the specificity of the sensor only with S. pyogenes. The genosensor exhibited a linear response to S. pyogenes G-DNA from 1 to1000 ng ml{sup −1} with a limit of detection of 0.16 ng ml{sup −1}.

Temperature shift experiments suggest that metabolic impairment and enhanced rates of photorespiration decrease organic acid levels in soybean leaflets exposed to supra-optimal growth temperatures

Science.gov (United States)

Citrate, malate, malonate, fumarate and succinate in soybean leaflets decreased 40 to 80% when plants were grown continuously in controlled environment chambers at 36/28 compared to 28/20 °C. Glycerate was not temperature responsive in this study. Temperature effects on the above mentioned organi...

HEART TRANSPLANTATION IN PATIENTS WITH PREVIOUS OPEN HEART SURGERY

Directory of Open Access Journals (Sweden)

R. Sh. Saitgareev

2016-01-01

Full Text Available Heart Transplantation (HTx to date remains the most effective and radical method of treatment of patients with end-stage heart failure. The defi cit of donor hearts is forcing to resort increasingly to the use of different longterm mechanical circulatory support systems, including as a «bridge» to the follow-up HTx. According to the ISHLT Registry the number of recipients underwent cardiopulmonary bypass surgery increased from 40% in the period from 2004 to 2008 to 49.6% for the period from 2009 to 2015. HTx performed in repeated patients, on the one hand, involves considerable technical diffi culties and high risks; on the other hand, there is often no alternative medical intervention to HTx, and if not dictated by absolute contradictions the denial of the surgery is equivalent to 100% mortality. This review summarizes the results of a number of published studies aimed at understanding the immediate and late results of HTx in patients, previously underwent open heart surgery. The effect of resternotomy during HTx and that of the specifi c features associated with its implementation in recipients previously operated on open heart, and its effects on the immediate and long-term survival were considered in this review. Results of studies analyzing the risk factors for perioperative complications in repeated recipients were also demonstrated. Separately, HTx risks after implantation of prolonged mechanical circulatory support systems were examined. The literature does not allow to clearly defi ning the impact factor of earlier performed open heart surgery on the course of perioperative period and on the prognosis of survival in recipients who underwent HTx. On the other hand, subject to the regular fl ow of HTx and the perioperative period the risks in this clinical situation are justifi ed as a long-term prognosis of recipients previously conducted open heart surgery and are comparable to those of patients who underwent primary HTx. Studies

How Does Subclinical Hyperthyroidism Affect Right Heart Function and Mechanics?

Science.gov (United States)

Tadic, Marijana; Celic, Vera; Cuspidi, Cesare; Ilic, Sanja; Zivanovic, Vladimir; Marjanovic, Tamara

2016-02-01

Right heart function and mechanics have not been investigated in patients with subclinical hyperthyroidism. Our aim was to investigate right ventricular (RV) and right atrial (RA) function and deformation as evaluated by 3-dimensional echocardiography (3DE) and speckle-tracking 2-dimensional echocardiography (2DE) in these individuals. We included 39 untreated women with endogenous subclinical hyperthyroidism and 39 healthy women matched by age. All participants underwent laboratory analyses that included thyroid hormone levels and comprehensive 2DE and 3DE examinations. Three-dimensional echocardiographic RV volumes were significantly elevated in the patients with subclinical hyperthyroidism (P < .05), whereas the 3DE RV ejection fraction was reduced in this group, but with borderline significance. Two-dimensional echocardiographic longitudinal RV and RA strain were significantly reduced in the patients with subclinical hyperthyroidism. Two-dimensional echocardiographic RV systolic and early diastolic strain rates were reduced, whereas late diastolic strain rates were increased in the patients with subclinical hyperthyroidism. The same changes were detected in RA mechanics among the patients with subclinical hyperthyroidism. The thyrotropin (TSH) level correlated with the left ventricular mass index, transmitral early diastolic peak flow velocity (E)/late diastolic flow velocity (A) ratio, tricuspid E/A ratio, 2DE RV global strain, 2DE RA, strain, and 3DE RV end-diastolic volume. A multivariate regression analysis showed that the mitral E/A ratio, 2DE RV global strain, and 3DE RV end-diastolic volume were independently associated with the TSH level. Right ventricular and RA function as evaluated by 3DE and speckle-tracking 2DE is significantly impaired in patients with subclinical hyperthyroidism. The TSH level correlated with parameters for RV function and mechanics in the whole study population. © 2016 by the American Institute of Ultrasound in Medicine.

Adjustable, physiological ventricular restraint improves left ventricular mechanics and reduces dilatation in an ovine model of chronic heart failure.

Science.gov (United States)

Ghanta, Ravi K; Rangaraj, Aravind; Umakanthan, Ramanan; Lee, Lawrence; Laurence, Rita G; Fox, John A; Bolman, R Morton; Cohn, Lawrence H; Chen, Frederick Y

2007-03-13

Ventricular restraint is a nontransplantation surgical treatment for heart failure. The effect of varying restraint level on left ventricular (LV) mechanics and remodeling is not known. We hypothesized that restraint level may affect therapy efficacy. We studied the immediate effect of varying restraint levels in an ovine heart failure model. We then studied the long-term effect of restraint applied over a 2-month period. Restraint level was quantified by use of fluid-filled epicardial balloons placed around the ventricles and measurement of balloon luminal pressure at end diastole. At 4 different restraint levels (0, 3, 5, and 8 mm Hg), transmural myocardial pressure (P(tm)) and indices of myocardial oxygen consumption (MVO2) were determined in control (n=5) and ovine heart failure (n=5). Ventricular restraint therapy decreased P(tm) and MVO2, and improved mechanical efficiency. An optimal physiological restraint level of 3 mm Hg was identified to maximize improvement without an adverse affect on systemic hemodynamics. At this optimal level, end-diastolic P(tm) and MVO2 indices decreased by 27% and 20%, respectively. The serial longitudinal effects of optimized ventricular restraint were then evaluated in ovine heart failure with (n=3) and without (n=3) restraint over 2 months. Optimized ventricular restraint prevented and reversed pathological LV dilatation (130+/-22 mL to 91+/-18 mL) and improved LV ejection fraction (27+/-3% to 43+/-5%). Measured restraint level decreased over time as the LV became smaller, and reverse remodeling slowed. Ventricular restraint level affects the degree of decrease in P(tm), the degree of decrease in MVO2, and the rate of LV reverse remodeling. Periodic physiological adjustments of restraint level may be required for optimal restraint therapy efficacy.

Fibrous composite material for textile heart valve design: in vitro assessment.

Science.gov (United States)

Amri, Amna; Laroche, Gaetan; Chakfe, Nabil; Heim, Frederic

2018-04-17

With over 150,000 implantations performed over the world, transcatheter aortic valve replacement (TAVR) has become a surgical technique, which largely competes with open surgery valve replacement for an increasing number of patients. The success of the procedure favors the research toward synthetic valve leaflet materials as an alternative to biological tissues, whose durability remains unknown. In particular, fibrous constructions have recently proven to be durable in vivo over a 6-month period of time in animal sheep models. Exaggerated fibrotic tissue formation remains, however, a critical issue to be addressed. This work investigates the design of a composite fibrous construction combining a woven polyethylene terephthalate (PET) layer and a non-woven PET mat, which are expected to provide, respectively, strength and appropriate topography toward limited fibrotic tissue ingrowth. For this purpose, a specific equipment has been developed to produce non-woven PET mats made from fibers with small diameter. These mats were assembled with woven PET substrates using various assembling techniques in order to obtain hybrid fibrous constructions. The physical and mechanical properties of the obtained materials were assessed and valve samples were manufactured to be tested in vitro for hydrodynamic performances. The results show that the composite fibrous construction is characterized by properties suitable for the valve leaflet function, but the durability of the assembling is however limited under accelerated cyclic loading.

The hippo pathway in heart development, regeneration, and diseases.

Science.gov (United States)

Zhou, Qi; Li, Li; Zhao, Bin; Guan, Kun-Liang

2015-04-10

The heart is the first organ formed during mammalian development. A properly sized and functional heart is vital throughout the entire lifespan. Loss of cardiomyocytes because of injury or diseases leads to heart failure, which is a major cause of human morbidity and mortality. Unfortunately, regenerative potential of the adult heart is limited. The Hippo pathway is a recently identified signaling cascade that plays an evolutionarily conserved role in organ size control by inhibiting cell proliferation, promoting apoptosis, regulating fates of stem/progenitor cells, and in some circumstances, limiting cell size. Interestingly, research indicates a key role of this pathway in regulation of cardiomyocyte proliferation and heart size. Inactivation of the Hippo pathway or activation of its downstream effector, the Yes-associated protein transcription coactivator, improves cardiac regeneration. Several known upstream signals of the Hippo pathway such as mechanical stress, G-protein-coupled receptor signaling, and oxidative stress are known to play critical roles in cardiac physiology. In addition, Yes-associated protein has been shown to regulate cardiomyocyte fate through multiple transcriptional mechanisms. In this review, we summarize and discuss current findings on the roles and mechanisms of the Hippo pathway in heart development, injury, and regeneration. © 2015 American Heart Association, Inc.

Effects of intravenous home dobutamine in palliative end-stage heart failure on quality of life, heart failure hospitalization, and cost expenditure.

Science.gov (United States)

Martens, Pieter; Vercammen, Jan; Ceyssens, Wendy; Jacobs, Linda; Luwel, Evert; Van Aerde, Herwig; Potargent, Peter; Renaers, Monique; Dupont, Matthias; Mullens, Wilfried

2018-01-17

In patients with palliative end-stage heart failure, interventions that could provide symptomatic relief and prevent hospital admissions are important. Ambulatory continuous intravenous inotropes have been advocated by guidelines for such a purpose. We sought to determine the effect of intravenous dobutamine on symptomatic status, hospital stay, mortality, and cost expenditure. All consecutive end-stage heart failure patients not amenable for advanced therapies and discharged with continuous intravenous home dobutamine from a single tertiary centre between April 2011 and January 2017 were retrospectively analysed. Dobutamine (fixed dose) was infused through a single-lumen central venous catheter with a small pump that was refilled by a nurse on a daily basis. Symptomatic status was longitudinally assessed as the change in New York Heart Association class and patient global assessment scale. Antecedent and incident heart failure hospitalizations were determined in a paired fashion, and cost impact was assessed. A total of 21 patients (age 77 ± 9 years) were followed up for 869 ± 647 days. At first follow-up (6 ± 1 weeks) after the initiation of dobutamine, patients had a significant improvement in New York Heart Association class (-1.29 ± 0.64; P heart failure hospitalizations assessed at 3, 6, and 12 months were significantly reduced (P heart failure hospitalizations over the same time period. Cost expenditure was significantly lower at 3 (P heart failure is feasible and associated with improved symptomatic status, heart failure hospitalizations, and health-care-related costs. Nevertheless, results should be interpreted in the context of the small and retrospective design. Larger studies are necessary to evaluate the effect of dobutamine in palliative end-stage heart failure. © 2018 The Authors. ESC Heart Failure published by John Wiley & Sons Ltd on behalf of the European Society of Cardiology.

Cardiac carcinoid: tricuspid delayed hyperenhancement on cardiac 64-slice multidetector CT and magnetic resonance imaging.

LENUS (Irish Health Repository)

Martos, R

2012-02-01

INTRODUCTION: Carcinoid heart disease is a rare condition in adults. Its diagnosis can be easily missed in a patient presenting to a primary care setting. We revised the advantages of using coronary multidetector computed tomography (MDCT) and cardiac magnetic resonance imaging (MRI) in diagnosing this condition. MATERIALS AND METHODS: We studied a 65-year-old patient with carcinoid heart disease and right heart failure using transthoracic Doppler-echocardiogram, cardiac MDCT and MRI. Cardiac echocardiogram revealed marked thickening and retraction of the tricuspid leaflets with dilated right atrium and ventricle. Cardiac MDCT and MRI demonstrated fixation and retraction of the tricuspid leaflets with delayed contrast hyperenhancement of the tricuspid annulus. CONCLUSION: This case demonstrates fascinating imaging findings of cardiac carcinoid disease and highlights the increasing utility of contrast-enhanced MRI and cardiac MDCT in the diagnosis of this interesting condition.

the Multitargets Pharmacological Mechanism of Qishenkeli Acting on the Coronary Heart Disease

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Yong Wang

2012-01-01

Full Text Available In this paper, we present a case study of Qishenkeli (QSKL to research TCM’s underlying molecular mechanism, based on drug target prediction and analyses of TCM chemical components and following experimental validation. First, after determining the compositive compounds of QSKL, we use drugCIPHER-CS to predict their potential drug targets. These potential targets are significantly enriched with known cardiovascular disease-related drug targets. Then we find these potential drug targets are significantly enriched in the biological processes of neuroactive ligand-receptor interaction, aminoacyl-tRNA biosynthesis, calcium signaling pathway, glycine, serine and threonine metabolism, and renin-angiotensin system (RAAS, and so on. Then, animal model of coronary heart disease (CHD induced by left anterior descending coronary artery ligation is applied to validate predicted pathway. RAAS pathway is selected as an example, and the results show that QSKL has effect on both rennin and angiotensin II receptor (AT1R, which eventually down regulates the angiotensin II (AngII. Bioinformatics combing with experiment verification can provide a credible and objective method to understand the complicated multitargets mechanism for Chinese herbal formula.

Machines versus medication for biventricular heart failure: focus on the total artificial heart.

Science.gov (United States)

Arabia, Francisco A; Moriguchi, Jaime D

2014-09-01

The medical/surgical management of advanced heart failure has evolved rapidly over the last few decades. With better understanding of heart failure pathophysiology, new pharmacological agents have been introduced that have resulted in improvements in survival. For those patients that fail to improve, mechanical circulatory support with left ventricular assist devices and total artificial hearts (TAHs) have served as a beneficial bridge to transplantation. The TAH has continued to play a significant role as a bridge to transplantation in patients with biventricular failure and more selected indications that could not be completely helped with left ventricular assist devices. Improved survival with the TAH has resulted in more patients benefiting from this technology. Improvements will eventually lead to a totally implantable device that will permanently replace the failing human heart.

Role of crystal orientation on chemical mechanical polishing of single crystal copper

Energy Technology Data Exchange (ETDEWEB)

Zhu, Aibin, E-mail: abzhu@mail.xjtu.edu.cn; He, Dayong; Luo, Wencheng; Liu, Yangyang

2016-11-15

Highlights: • The role of crystal orientation in cooper CMP by quasi-continuum was studied. • The atom displacement diagrams were obtained and analyzed. • The stress distribution diagrams and load-displacement curves were analyzed. • This research is helpful to revealing the material removal mechanism of CMP. - Abstract: The material removal mechanism of single crystal copper in chemical mechanical polishing (CMP) has not been intensively investigated. And the role of crystal orientation in CMP of single crystal cooper is not quite clear yet. Quasi-continuum method was adopted in this paper to simulate the process of nano-particles grinding on single crystal copper in CMP process. Three different crystal orientations, i.e. x[100]y[001], x[001]y[110] and x[–211]y[111], were chosen for analysis. The atom displacement diagrams, stress distribution diagrams and load-displacement curves were obtained. After analyzing the deformation mechanism, residual stress of the work piece material and cutting force, results showed that, the crystal orientation of work piece has great influence on the deformation characteristics and surface quality of work piece during polishing. In the A(001)[100] orientation, the residual stress distribution after polishing is deeper, and the stress is larger than that in the B(110)[001] and C(111)[–211] orientations. And the average tangential cutting force in the A(001)[100] orientation is much larger than those in the other two crystal orientation. This research is helpful to revealing the material removal mechanism of CMP process.

MRI in ischemic heart disease

International Nuclear Information System (INIS)

Hazirolan, T.

2012-01-01

Full text: The role of magnetic resonance imaging in the evaluation of ischemic heart disease has increased over the last years. Cardiac MRI is the only imaging modality that provides 'one stop shop' assessment. Information about ventricular function, myocardial ischemia and myocardial viability can be obtained in a single cardiac MRI session. Additionally, Cardiac MRI has become a gold standard method in evaluation of myocardial viability and in assessment of ventricular mass and function. As a result, cardiac MRI enable radiologist to comprehensively assess ischemic heart disease. The aim of this presentation is to provide the reader a state-of-the art on how the newest cardiac MRI techniques can be used to study ischemic heart disease patients.

Relationship between lung-to-heart uptake ratio of technetium-99m-tetrofosmin during exercise myocardial single photon emission computed tomographic imaging and the number of diseased coronary arteries in patients with effort angina pectoris without myocardial infarction

International Nuclear Information System (INIS)

Okajima, Toshiya; Ueshima, Kenji; Nishiyama, Osamu; Ogawa, Muneyoshi; Ohuchi, Mami; Saitoh, Masahiko; Hiramori, Katsuhiko

2004-01-01

Increased lung uptake of thallium-201 in exercise myocardial perfusion imaging is a reliable marker of multivessel disease in patients with ischemic heart disease. This study investigated whether the lung-to-heart uptake ratio with technetium-99m ( 99m Tc)-tetrofosmin also provides valuable information to detect patients with multivessel disease. Fifty-three consecutive patients (35 men, 18 women, mean age 66±11 years; single-vessel disease: 29, double-vessel disease: 16, triple-vessel disease: 8) with stable effort angina pectoris without prior myocardial infarction and 17 control subjects (12 men, 5 women, mean age 62±9 years) underwent exercise myocardial perfusion imaging with 99m Tc-tetrofosmin and coronary angiography in January 2000 to December 2002. The lung-to-heart uptake ratio was calculated on an anterior projection before reconstruction of the exercise single photon emission computed tomographic images. The mean lung-to-heart uptake ratio was 0.34±0.04, 0.38±0.07, 0.41±0.05, and 0.46±0.09, in patients with normal coronary, single-vessel disease, double-vessel disease, and triple-vessel disease, respectively. Significantly higher lung-to-heart uptake ratio was associated with more diseased vessels (p 99m Tc-tetrofosmin can provide clinically useful information to detect multivessel disease in patients with ischemic heart disease. (author)

Nano-Electromechanical Systems: Displacement Detection and the Mechanical Single Electron Shuttle

Science.gov (United States)

Blick, R. H.; Beil, F. W.; Höhberger, E.; Erbe, A.; Weiss, C.

For an introduction to nano-electromechanical systems we present measurements on nanomechanical resonators operating in the radio frequency range. We discuss in detail two different schemes of displacement detection for mechanical resonators, namely conventional reflection measurements of a probing signal and direct detection by capacitive coupling via a gate electrode. For capacitive detection we employ an on-chip preamplifier, which enables direct measurements of the resonator's disp lacement. We observe that the mechanical quality factor of the resonator depends on the detection technique applied, which is verified in model calculations and report on the detection of sub-harmonics. In the second part we extend our investigations to include transport of single electrons through an electron island on the tip of a nanomachined mechanical pendulum. The pendulum is operated by applying a modulating electromagnetic field in the range of 1 - 200 MHz, leading to mechanical oscillations between two laterally integrated source and drain contacts. Forming tunneling barriers the metallic tip shuttles single electrons from source to drain. The resulting tunneling current shows distinct features corresponding to the discrete mechanical eigenfrequencies of the pendulum. We report on measurements covering the temperature range from 300 K down to 4.2 K. The transport properties of the device are compared in detail to model calculations based on a Master-equation approach.

The lateral paragigantocellular nucleus modulates parasympathetic cardiac neurons: a mechanism for rapid eye movement sleep-dependent changes in heart rate.

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Dergacheva, Olga; Wang, Xin; Lovett-Barr, Mary R; Jameson, Heather; Mendelowitz, David

2010-08-01

Rapid eye movement (REM) sleep is generally associated with a withdrawal of parasympathetic activity and heart rate increases; however, episodic vagally mediated heart rate decelerations also occur during REM sleep. This alternating pattern of autonomic activation provides a physiological basis for REM sleep-induced cardiac arrhythmias. Medullary neurons within the lateral paragigantocellular nucleus (LPGi) are thought to be active after REM sleep recovery and play a role in REM sleep control. In proximity to the LPGi are parasympathetic cardiac vagal neurons (CVNs) within the nucleus ambiguus (NA), which are critical for controlling heart rate. This study examined brain stem pathways that may mediate REM sleep-related reductions in parasympathetic cardiac activity. Electrical stimulation of the LPGi evoked inhibitory GABAergic postsynaptic currents in CVNs in an in vitro brain stem slice preparation in rats. Because brain stem cholinergic mechanisms are involved in REM sleep regulation, we also studied the role of nicotinic neurotransmission in modulation of GABAergic pathway from the LGPi to CVNs. Application of nicotine diminished the GABAergic responses evoked by electrical stimulation. This inhibitory effect of nicotine was prevented by the alpha7 nicotinic receptor antagonist alpha-bungarotoxin. Moreover, hypoxia/hypercapnia (H/H) diminished LPGi-evoked GABAergic current in CVNs, and this inhibitory effect was also prevented by alpha-bungarotoxin. In conclusion, stimulation of the LPGi evokes an inhibitory pathway to CVNs, which may constitute a mechanism for the reduced parasympathetic cardiac activity and increase in heart rate during REM sleep. Inhibition of this pathway by nicotinic receptor activation and H/H may play a role in REM sleep-related and apnea-associated bradyarrhythmias.

Chemo-mechanical pushing of proteins along single-stranded DNA.

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Sokoloski, Joshua E; Kozlov, Alexander G; Galletto, Roberto; Lohman, Timothy M

2016-05-31

Single-stranded (ss)DNA binding (SSB) proteins bind with high affinity to ssDNA generated during DNA replication, recombination, and repair; however, these SSBs must eventually be displaced from or reorganized along the ssDNA. One potential mechanism for reorganization is for an ssDNA translocase (ATP-dependent motor) to push the SSB along ssDNA. Here we use single molecule total internal reflection fluorescence microscopy to detect such pushing events. When Cy5-labeled Escherichia coli (Ec) SSB is bound to surface-immobilized 3'-Cy3-labeled ssDNA, a fluctuating FRET signal is observed, consistent with random diffusion of SSB along the ssDNA. Addition of Saccharomyces cerevisiae Pif1, a 5' to 3' ssDNA translocase, results in the appearance of isolated, irregularly spaced saw-tooth FRET spikes only in the presence of ATP. These FRET spikes result from translocase-induced directional (5' to 3') pushing of the SSB toward the 3' ssDNA end, followed by displacement of the SSB from the DNA end. Similar ATP-dependent pushing events, but in the opposite (3' to 5') direction, are observed with EcRep and EcUvrD (both 3' to 5' ssDNA translocases). Simulations indicate that these events reflect active pushing by the translocase. The ability of translocases to chemo-mechanically push heterologous SSB proteins along ssDNA provides a potential mechanism for reorganization and clearance of tightly bound SSBs from ssDNA.

Force spectroscopy studies on protein-ligand interactions: a single protein mechanics perspective.

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Hu, Xiaotang; Li, Hongbin

2014-10-01

Protein-ligand interactions are ubiquitous and play important roles in almost every biological process. The direct elucidation of the thermodynamic, structural and functional consequences of protein-ligand interactions is thus of critical importance to decipher the mechanism underlying these biological processes. A toolbox containing a variety of powerful techniques has been developed to quantitatively study protein-ligand interactions in vitro as well as in living systems. The development of atomic force microscopy-based single molecule force spectroscopy techniques has expanded this toolbox and made it possible to directly probe the mechanical consequence of ligand binding on proteins. Many recent experiments have revealed how ligand binding affects the mechanical stability and mechanical unfolding dynamics of proteins, and provided mechanistic understanding on these effects. The enhancement effect of mechanical stability by ligand binding has been used to help tune the mechanical stability of proteins in a rational manner and develop novel functional binding assays for protein-ligand interactions. Single molecule force spectroscopy studies have started to shed new lights on the structural and functional consequence of ligand binding on proteins that bear force under their biological settings. Copyright © 2014 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Exploring consumer opinions on the presentation of side-effects information in Australian Consumer Medicine Information leaflets.

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