Effects of orientation and downward-facing convex curvature on pool-boiling critical heat flux
NASA Astrophysics Data System (ADS)
Howard, Alicia Ann Harris
Photographic studies of near-saturated pool boiling on both inclined flat surfaces and a downward-facing convex surface were conducted in order to determine the physical mechanisms that trigger critical heat flux (CHF). Based on the vapor behavior observed just prior to CHF, it is shown for the flat surfaces that the surface orientations can be divided into three regions: upward-facing (0-60°), near-vertical (60-165°), and downward-facing (165-180°) each region is associated with a unique CHIP trigger mechanism. In the upward-facing region, the buoyancy forces remove the vapor vertically off the heater surface. The near- vertical region is characterized by a wavy liquid-vapor interface which sweeps along the heater surface. In the downward-facing region, the vapor repeatedly stratifies on the heater surface, greatly decreasing CHF. The vapor behavior along the convex surface is cyclic in nature and similar to the nucleation/coalescence/stratification/release procedure observed for flat surfaces in the downward-facing region. The vapor stratification occurred at the bottom (downward-facing) heaters on the convex surface. CHF is always triggered on these downward-facing heaters and then propagates up the convex surface, and the orientations of these heaters are comparable with the orientation range of the flat surface downward-facing region. The vast differences between the observed vapor behavior within the three regions and on the convex surface indicate that a single overall pool boiling CHF model cannot possibly account for all the observed effects. Upward-facing surfaces have been examined and modeled extensively by many investigators and a few investigators have addressed downward-facing surfaces, so this investigation focuses on modeling the near-vertical region. The near-vertical CHF model incorporates classical two-dimensional interfacial instability theory, a separated flow model, an energy balance, and a criterion for separation of the wavy interface from the surface at CHF. The model was tested for different fluids and shows good agreement with CHF data. Additionally, the instability theory incorporated into this model accurately predicts the angle of transition between the near-vertical and downward-facing regions.
A comparison of critical heat flux in tubes and bilaterally heated annuli
DOE Office of Scientific and Technical Information (OSTI.GOV)
Doerffer, S.; Groeneveld, D.C.; Cheng, S.C.
1995-09-01
This paper examines the critical heat flux (CHF) behaviour for annular flow in bilaterally heated annuli and compares it to that in tubes and unilaterally heated annuli. It was found that the differences in CHF between bilaterally and unilaterally heated annuli or tubes strongly depend on pressure and quality. the CHF in bilaterally heated annuli can be predicted by tube CHF prediction methods for the simultaneous CHF occurrence at both surfaces, and the following flow conditions: pressure 7-10 MPa, mass flux 0.5-4.0 Mg/m{sup 2}s and critical quality 0.23-0.9. The effect on CHF of the outer-to-inner surface heat flux ratio, wasmore » also examined. The prediction of CHF for bilaterally heated annuli was based on the droplet-diffusion model proposed by Kirillov and Smogalev. While their model refers only to CHF occurrence at the inner surface, we extended it to cases where CHF occurs at the outer surface, and simultaneously at both surfaces, thus covering all cases of CHF occurrence in bilaterally heated annuli. From the annuli CHF data of Becker and Letzter, we derived empirical functions required by the model. the proposed equations provide good accuracy for the CHF data used in this study. Moreover, the equations can predict conditions at which CHF occurs simultaneously at both surfaces. Also, this method can be used for cases with only one heated surface.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Boyd, R.D.
Microconvective, instability, experimental, and correlational aspects of subcooled flow boiling critical heat flux (CHF) are summarized. The present understanding of CHF in subcooled flow boiling is reviewed and research directions that will permit the accommodation of higher heat fluxes are outlined. This survey (Parts I and II), which contains a representative coverage of the literature over the last 30 years, is concerned only with CHF in the subcooled flow boiling regime, and unless otherwise noted, all references to CHF are confined to that regime.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Corradini, Michael; Wu, Qiao
2015-04-30
This report is a preliminary document presenting an overview of the Critical Heat Flux (CHF) phenomenon, the High Pressure Critical Heat Flux facility (HPCHF), preliminary CHF data acquired, and the future direction of the research. The HPCHF facility has been designed and built to study CHF at high pressure and low mass flux ranges in a rod bundle prototypical of conceptual Small Modular Reactor (SMR) designs. The rod bundle is comprised of four electrically heated rods in a 2x2 square rod bundle with a prototypic chopped-cosine axial power profile and equipped with thermocouples at various axial and circumferential positions embeddedmore » in each rod for CHF detection. Experimental test parameters for CHF detection range from pressures of ~80 – 160 bar, mass fluxes of ~400 – 1500 kg/m2s, and inlet water subcooling from ~30 – 70°C. The preliminary data base established will be further extended in the future along with comparisons to existing CHF correlations, models, etc. whose application ranges may be applicable to the conditions of SMRs.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Boyd, R.D.
This paper reviews the present understanding of critical heat flux (CHF) in subcooled flow boiling and outlines research directions which will permit the accommodation of higher heat fluxes. This survey, which covers the last 30 years, is concerned only with CHF in the subcooled flow boiling regime and unless otherwise noted, all references to CHF will be confined to that regime. This paper (Part II) summarizes microconvective, instability, experimental and correlational aspects of CHF. Section II covers microconvection and instabilities, section III covers representative experimental work, and section IV summarizes and compares selected CHF correlations. Section V documents previous flowmore » visualization work and section VI contains conclusions and recommendations concerning problem areas and suggested research directions essential to the HHFCDP, which involves extending steady state and transient CHF towards 30 kW/cm/sup 2/.« less
On the look-up tables for the critical heat flux in tubes (history and problems)
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kirillov, P.L.; Smogalev, I.P.
1995-09-01
The complication of critical heat flux (CHF) problem for boiling in channels is caused by the large number of variable factors and the variety of two-phase flows. The existence of several hundreds of correlations for the prediction of CHF demonstrates the unsatisfactory state of this problem. The phenomenological CHF models can provide only the qualitative predictions of CHF primarily in annular-dispersed flow. The CHF look-up tables covered the results of numerous experiments received more recognition in the last 15 years. These tables are based on the statistical averaging of CHF values for each range of pressure, mass flux and quality.more » The CHF values for regions, where no experimental data is available, are obtained by extrapolation. The correction of these tables to account for the diameter effect is a complicated problem. There are ranges of conditions where the simple correlations cannot produce the reliable results. Therefore, diameter effect on CHF needs additional study. The modification of look-up table data for CHF in tubes to predict CHF in rod bundles must include a method which to take into account the nonuniformity of quality in a rod bundle cross section.« less
Investigation of Critical Heat Flux in Reduced Gravity Using Photomicrographic Techniques
NASA Technical Reports Server (NTRS)
Mudawar, Issam; Zhang, Hui
2003-01-01
Experiments were performed to examine the effects of body force on flow boiling critical heat flux (CHF). FC-72 was boiled along one wall of a transparent rectangular flow channel that permitted photographic study of the vapor-liquid interface just prior to CHF. High-speed video imaging techniques were used to identify dominant CHF mechanisms corresponding to different flow orientations and liquid velocities. Six different CHF regimes were identified: Wavy Vapor Layer, Pool Boiling, Stratification, Vapor Counterflow, Vapor Stagnation, and Separated Concurrent Vapor Flow. CHF showed significant sensitivity to orientation for flow velocities below 0.2 m/s, where extremely low CHF values where measured, especially with downward-facing heated wall and downflow orientations. High flow velocities dampened the effects of orientation considerably. The CHF data were used to assess the suitability of previous CHF models and correlations. It is shown the Interfacial Lift-off Model is very effective at predicting CHF for high velocities at all orientations. The flooding limit, on the other hand, is useful at estimating CHF at low velocities and for downflow orientations. A new method consisting of three dimensionless criteria is developed for determining the minimum flow velocity required to overcome body force effects on near-saturated flow boiling CHF. Vertical upflow boiling experiments were performed in pursuit of identifying the trigger mechanism for subcooled flow boiling CHF. While virtually all prior studies on flow boiling CHF concern the prediction or measurement of conditions that lead to CHF, this study was focused on events that take place during the CHF transient. High-speed video imaging and photomicrographic techniques were used to record the transient behavior of interfacial features from the last steady-state power level before CHF until the moment of power cut-off following CHF. The video records show the development of a wavy vapor layer which propagates along the heated wall, permitting cooling prior to CHF only in wetting fronts corresponding to the wave troughs. Image analysis software was developed to estimate void fraction from the individual video images. The void fraction records for subcooled flow boiling show the CHF transient is accompanied by gradual lift-off of wetting fronts culminating in some maximum vapor layer mean thickness, following which the vapor layer begins to thin down as the transition to film boiling ensues. This study proves the Interfacial Lift-off Model, which has been validated for near-saturated flow boiling CHF, is equally valid for subcooled conditions.
Reversal of OFI and CHF in Research Reactors Operating at 1 to 50 Bar. Version 1.0
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kalimullah, M.; Olson, A. P.; Dionne, B.
2014-02-28
The conditions at which the critical heat flux (CHF) and the heat flux at the onset of Ledinegg flow instability (OFI) are equal, are determined for a coolant channel with uniform heat flux as a function of five independent parameters: the channel exit pressure (P), heated length (Lh) , heated diameter (Dh), inlet temperature (Tin), and mass flux (G). A diagram is made by plotting the mass flux and heat flux at the OFI-CHF intersection (reversal from CHF > OFI to CHF < OFI as G increases) as a function of P (1 to 50 bar), for 36 combinations ofmore » the remaining three parameters (Lh , Dh , Tin): Lh = 0.28, 0.61, 1.18 m; Dh = 3, 4, 6, 8 mm; Tin = 30, 50, 70 °C. The use of the diagram to scope whether a research reactor is OFI-limited (below the curve) or CHF-limited based on the five parameters of its coolant channel is described. Justification for application of the diagram to research reactors with axially non-uniform heat flux is provided. Due to its limitations (uncertainties not included), the diagram cannot replace the detailed thermal-hydraulic analysis required for a reactor safety analysis. In order to make the OFI-CHF intersection diagram, two world-class CHF prediction methods (the Hall-Mudawar correlation and the extended Groeneveld 2006 table) are compared for 216 combinations of the five independent parameters. The two widely used OFI correlations (the Saha- Zuber and the Whittle-Forgan with η = 32.5) are also compared for the same combinations of the five parameters. The extended Groeneveld table and the Whittle-Forgan OFI correlation are selected for use in making the diagram. Using the above five design parameters, a research reactor can be represented by a point on the reversal diagram, and the diagram can be used to scope, without a thermal-hydraulic calculation, whether the OFI will occur before the CHF, or the CHF will occur before the OFI when the reactor power is increased keeping the five parameters fixed.« less
NASA Technical Reports Server (NTRS)
Kim, J. S.; Rao, M. V. V. S.; Cappelli, M. A.; Sharma, S. P.; Meyyappan, M.; Arnold, Jim (Technical Monitor)
2000-01-01
Absolute fluxes and energy distributions of ions in inductively coupled plasmas of Ar, CHF3/Ar, and CHF3/Ar/O2 have been measured. These plasmas were generated in a Gaseous Electronics Conference (GEC) cell modified for inductive coupling at pressures 10-50 mTorr and 100-300 W of 13.56 MHz radio frequency (RF) power in various feedgas mixtures. In pure Ar plasmas, the Ar(+) flux increases linearly with pressure as well as RF-power. Total ion flux in CHF3 mixtures decreases with increase in pressure and also CHF3 concentration. Relative ion fluxes observed in the present studies are analyzed with the help of available cross sections for electron impact ionization and charge-exchange ion-molecule reactions. Measurements of plasma potential, electron and ion number densities, electron energy distribution function, and mean electron energy have also been made in the center of the plasma with a RF compensated Langmuir probe. Plasma potential values are compared with the mean ion energies determined from the measured ion energy distributions and are consistent. Electron temperature, plasma potential, and mean ion energy vary inversely with pressure, but increase with CHF3 content in the mixture.
Critical heat flux (CHF) phenomenon on a downward facing curved surface
DOE Office of Scientific and Technical Information (OSTI.GOV)
Cheung, F.B.; Haddad, K.H.; Liu, Y.C.
1997-06-01
This report describes a theoretical and experimental study of the boundary layer boiling and critical heat flux phenomena on a downward facing curved heating surface, including both hemispherical and toroidal surfaces. A subscale boundary layer boiling (SBLB) test facility was developed to measure the spatial variation of the critical heat flux and observe the underlying mechanisms. Transient quenching and steady-state boiling experiments were performed in the SBLB facility under both saturated and subcooled conditions to obtain a complete database on the critical heat flux. To complement the experimental effort, an advanced hydrodynamic CHF model was developed from the conservation lawsmore » along with sound physical arguments. The model provides a clear physical explanation for the spatial variation of the CHF observed in the SBLB experiments and for the weak dependence of the CHF data on the physical size of the vessel. Based upon the CHF model, a scaling law was established for estimating the local critical heat flux on the outer surface of a heated hemispherical vessel that is fully submerged in water. The scaling law, which compares favorably with all the available local CHF data obtained for various vessel sizes, can be used to predict the local CHF limits on large commercial-size vessels. This technical information represents one of the essential elements that is needed in assessing the efficacy of external cooling of core melt by cavity flooding as a severe accident management strategy. 83 figs., 3 tabs.« less
Critical heat flux in subcooled flow boiling
NASA Astrophysics Data System (ADS)
Hall, David Douglas
The critical heat flux (CHF) phenomenon was investigated for water flow in tubes with particular emphasis on the development of methods for predicting CHF in the subcooled flow boiling regime. The Purdue University Boiling and Two-Phase Flow Laboratory (PU-BTPFL) CHF database for water flow in a uniformly heated tube was compiled from the world literature dating back to 1949 and represents the largest CHF database ever assembled with 32,544 data points from over 100 sources. The superiority of this database was proven via a detailed examination of previous databases. The PU-BTPFL CHF database is an invaluable tool for the development of CHF correlations and mechanistic models that are superior to existing ones developed with smaller, less comprehensive CHF databases. In response to the many inaccurate and inordinately complex correlations, two nondimensional, subcooled CHF correlations were formulated, containing only five adjustable constants and whose unique functional forms were determined without using a statistical analysis but rather using the parametric trends observed in less than 10% of the subcooled CHF data. The correlation based on inlet conditions (diameter, heated length, mass velocity, pressure, inlet quality) was by far the most accurate of all known subcooled CHF correlations, having mean absolute and root-mean-square (RMS) errors of 10.3% and 14.3%, respectively. The outlet (local) conditions correlation was the most accurate correlation based on local CHF conditions (diameter, mass velocity, pressure, outlet quality) and may be used with a nonuniform axial heat flux. Both correlations proved more accurate than a recent CHF look-up table commonly employed in nuclear reactor thermal hydraulic computer codes. An interfacial lift-off, subcooled CHF model was developed from a consideration of the instability of the vapor-liquid interface and the fraction of heat required for liquid-vapor conversion as opposed to that for bulk liquid heating. Severe vapor effusion in an upstream wetting front lifts the vapor-liquid interface off the surface, triggering CHF. Since the model is entirely based on physical observations, it has the potential to accurately predict CHF for other fluids and flow geometries which are beyond the conditions for which it was validated.
Enhancement of critical heat flux in nucleate boiling of nanofluids: a state-of-art review
2011-01-01
Nanofluids (suspensions of nanometer-sized particles in base fluids) have recently been shown to have nucleate boiling critical heat flux (CHF) far superior to that of the pure base fluid. Over the past decade, numerous experimental and analytical studies on the nucleate boiling CHF of nanofluids have been conducted. The purpose of this article is to provide an exhaustive review of these studies. The characteristics of CHF enhancement in nanofluids are systemically presented according to the effects of the primary boiling parameters. Research efforts to identify the effects of nanoparticles underlying irregular enhancement phenomena of CHF in nanofluids are then presented. Also, attempts to explain the physical mechanism based on available CHF theories are described. Finally, future research needs are identified. PMID:21711949
Experimental and analytical studies of high heat flux components for fusion experimental reactor
NASA Astrophysics Data System (ADS)
Araki, Masanori
1993-03-01
In this report, the experimental and analytical results concerning the development of plasma facing components of ITER are described. With respect to developing high heat removal structures for the divertor plates, an externally-finned swirl tube was developed based on the results of critical heat flux (CHF) experiments on various tube structures. As the result, the burnout heat flux, which also indicates incident CHF, of 41 (+/-) 1 MW/sq m was achieved in the externally-finned swirl tube. The applicability of existing CHF correlations based on uniform heating conditions was evaluated by comparing the CHF experimental data with the smooth and the externally-finned tubes under one-sided heating condition. As the results, experimentally determined CHF data for straight tube show good agreement, for the externally-finned tube, no existing correlations are available for prediction of the CHF. With respect to the evaluation of the bonds between carbon-based material and heat sink metal, results of brazing tests were compared with the analytical results by three dimensional model with temperature-dependent thermal and mechanical properties. Analytical results showed that residual stresses from brazing can be estimated by the analytical three directional stress values instead of the equivalent stress value applied. In the analytical study on the separatrix sweeping for effectively reducing surface heat fluxes on the divertor plate, thermal response of the divertor plate was analyzed under ITER relevant heat flux conditions and has been tested. As the result, it has been demonstrated that application of the sweeping technique is very effective for improvement in the power handling capability of the divertor plate and that the divertor mock-up has withstood a large number of additional cyclic heat loads.
Impact of Different Correlations on TRACEv4.160 Predicted Critical Heat Flux
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jasiulevicius, A.; Macian-Juan, R.
2006-07-01
This paper presents an independent assessment of the Critical Heat Flux (CHF) models implemented in TRACEv4.160 with data from the experiments carried out at the Royal Institute of Technology (RIT) in Stockholm, Sweden, with single vertical uniformly heated 7.0 m long tubes. In previous CHF assessment studies with TRACE, it was noted that, although the overall code predictions in long single tubes with inner diameters of 1.0 to 2.49 cm agreed rather well with the results of experiments (with r.m.s. error being 25.6%), several regions of pressure and coolant mass flux could be identified, in which the code strongly under-predictsmore » or over-predicts the CHF. In order to evaluate the possibility of improving the code performance, some of the most widely used and assessed CHF correlations were additionally implemented in TRACEv4.160, namely Bowring, Levitan - Lantsman, and Tong-W3. The results obtained for the CHF predictions in single tubes with uniform axial heat flux by using these correlations, were compared to the results produced with the standard TRACE correlations (Biasi and CISE-GE), and with the experimental data from RIT, which covered a broad range of pressures (3-20 MPa) and coolant mass fluxes (500-3000 kg/m{sup 2}s). Several hundreds of experimental points were calculated to cover the parameter range mentioned above for the evaluation of the newly implemented correlations in the TRACEv4.160 code. (author)« less
Critical heat flux maxima during boiling crisis on textured surfaces
Dhillon, Navdeep Singh; Buongiorno, Jacopo; Varanasi, Kripa K.
2015-01-01
Enhancing the critical heat flux (CHF) of industrial boilers by surface texturing can lead to substantial energy savings and global reduction in greenhouse gas emissions, but fundamentally this phenomenon is not well understood. Prior studies on boiling crisis indicate that CHF monotonically increases with increasing texture density. Here we report on the existence of maxima in CHF enhancement at intermediate texture density using measurements on parametrically designed plain and nano-textured micropillar surfaces. Using high-speed optical and infrared imaging, we study the dynamics of dry spot heating and rewetting phenomena and reveal that the dry spot heating timescale is of the same order as that of the gravity and liquid imbibition-induced dry spot rewetting timescale. Based on these insights, we develop a coupled thermal-hydraulic model that relates CHF enhancement to rewetting of a hot dry spot on the boiling surface, thereby revealing the mechanism governing the hitherto unknown CHF enhancement maxima. PMID:26346098
Flow regimes and mechanistic modeling of critical heat flux under subcooled flow boiling conditions
NASA Astrophysics Data System (ADS)
Le Corre, Jean-Marie
Thermal performance of heat flux controlled boiling heat exchangers are usually limited by the Critical Heat Flux (CHF) above which the heat transfer degrades quickly, possibly leading to heater overheating and destruction. In an effort to better understand the phenomena, a literature review of CHF experimental visualizations under subcooled flow boiling conditions was performed and systematically analyzed. Three major types of CHF flow regimes were identified (bubbly, vapor clot and slug flow regime) and a CHF flow regime map was developed, based on a dimensional analysis of the phenomena and available data. It was found that for similar geometric characteristics and pressure, a Weber number (We)/thermodynamic quality (x) map can be used to predict the CHF flow regime. Based on the experimental observations and the review of the available CHF mechanistic models under subcooled flow boiling conditions, hypothetical CHF mechanisms were selected for each CHF flow regime, all based on a concept of wall dry spot overheating, rewetting prevention and subsequent dry spot spreading. It is postulated that a high local wall superheat occurs locally in a dry area of the heated wall, due to a cyclical event inherent to the considered CHF two-phase flow regime, preventing rewetting (Leidenfrost effect). The selected modeling concept has the potential to span the CHF conditions from highly subcooled bubbly flow to early stage of annular flow. A numerical model using a two-dimensional transient thermal analysis of the heater undergoing nucleation was developed to mechanistically predict CHF in the case of a bubbly flow regime. In this type of CHF two-phase flow regime, the high local wall superheat occurs underneath a nucleating bubble at the time of bubble departure. The model simulates the spatial and temporal heater temperature variations during nucleation at the wall, accounting for the stochastic nature of the boiling phenomena. The model has also the potential to evaluate the post-DNB heater temperature up to the point of heater melting. Validation of the proposed model was performed using detailed measured wall boiling parameters near CHF, thereby bypassing most needed constitutive relations. It was found that under limiting nucleation conditions; a peak wall temperature at the time of bubble departure can be reached at CHF preventing wall cooling by quenching. The simulations show that the resulting dry patch can survive the surrounding quenching event, preventing further nucleation and leading to a fast heater temperature increase. For more practical applications, the model was applied at known CHF conditions in simple geometry coupled with one-dimensional and three-dimensional (CFD) codes. It was found that, in the case where CHF occurs under bubbly flow conditions, the local wall superheat underneath nucleating bubbles is predicted to reach the Leidenfrost temperature. However, a better knowledge of statistical variations in wall boiling parameters would be necessary to correctly capture the CHF trends with mass flux (or Weber number). In addition, consideration of relevant parameter influences on the Leidenfrost temperature and consideration of interfacial microphysics at the wall would allow improved simulation of the wall rewetting prevention and subsequent dry patch spreading.
Frey, Anna; Popp, Sandy; Post, Antonia; Langer, Simon; Lehmann, Marc; Hofmann, Ulrich; Sirén, Anna-Leena; Hommers, Leif; Schmitt, Angelika; Strekalova, Tatyana; Ertl, Georg; Lesch, Klaus-Peter; Frantz, Stefan
2014-01-01
Depression and anxiety are common and independent outcome predictors in patients with chronic heart failure (CHF). However, it is unclear whether CHF causes depression. Thus, we investigated whether mice develop anxiety- and depression-like behavior after induction of ischemic CHF by myocardial infarction (MI). In order to assess depression-like behavior, anhedonia was investigated by repeatedly testing sucrose preference for 8 weeks after coronary artery ligation or sham operation. Mice with large MI and increased left ventricular dimensions on echocardiography (termed CHF mice) showed reduced preference for sucrose, indicating depression-like behavior. 6 weeks after MI, mice were tested for exploratory activity, anxiety-like behavior and cognitive function using the elevated plus maze (EPM), light-dark box (LDB), open field (OF), and object recognition (OR) tests. In the EPM and OF, CHF mice exhibited diminished exploratory behavior and motivation despite similar movement capability. In the OR, CHF mice had reduced preference for novelty and impaired short-term memory. On histology, CHF mice had unaltered overall cerebral morphology. However, analysis of gene expression by RNA-sequencing in prefrontal cortical, hippocampal, and left ventricular tissue revealed changes in genes related to inflammation and cofactors of neuronal signal transduction in CHF mice, with Nr4a1 being dysregulated both in prefrontal cortex and myocardium after MI. After induction of ischemic CHF, mice exhibited anhedonic behavior, decreased exploratory activity and interest in novelty, and cognitive impairment. Thus, ischemic CHF leads to distinct behavioral changes in mice analogous to symptoms observed in humans with CHF and comorbid depression.
NASA Astrophysics Data System (ADS)
Bobkov, V. P.
2015-02-01
Some general matters concerned with description of burnout in channels are outlined. Data obtained from experimental investigations on critical heat fluxes (CHF) in different channels, CHF data banks, the main determining parameters, CHF basic dependences, and a system of correction functions are discussed. Two methods for estimating the CHF description errors are analyzed. The influence of operating parameters, transverse sizes of channels, and conditions at their inlet are analyzed. The effects of heat-transfer surface shape and heat supply arrangement are considered for concentric annular channels. The notions of a thermal boundary layer and an elementary thermal cell during burnout in channels with an intricate cross section are defined. New notions for describing CHF in rod assemblies are introduced: bundle effect, thermal misalignment, assembly-section-averaged and local parameters (for an elementary cell), cell-wise CHF analysis in bundles, and standard and nonstandard cells. Possible influence of wall thermophysical properties on CHF in dense assemblies and other effects are considered. Thermal interaction of nonequivalent cells and the effect of heat supply arrangement over the cell perimeter are analyzed. Special attention is paid to description of the effect the heat release nonuniformity along the channels has on CHF. Objectives to be pursued by studies of CHF in channels of different cross-section shapes are formulated.
Frey, Anna; Popp, Sandy; Post, Antonia; Langer, Simon; Lehmann, Marc; Hofmann, Ulrich; Sirén, Anna-Leena; Hommers, Leif; Schmitt, Angelika; Strekalova, Tatyana; Ertl, Georg; Lesch, Klaus-Peter; Frantz, Stefan
2014-01-01
Background: Depression and anxiety are common and independent outcome predictors in patients with chronic heart failure (CHF). However, it is unclear whether CHF causes depression. Thus, we investigated whether mice develop anxiety- and depression-like behavior after induction of ischemic CHF by myocardial infarction (MI). Methods and Results: In order to assess depression-like behavior, anhedonia was investigated by repeatedly testing sucrose preference for 8 weeks after coronary artery ligation or sham operation. Mice with large MI and increased left ventricular dimensions on echocardiography (termed CHF mice) showed reduced preference for sucrose, indicating depression-like behavior. 6 weeks after MI, mice were tested for exploratory activity, anxiety-like behavior and cognitive function using the elevated plus maze (EPM), light-dark box (LDB), open field (OF), and object recognition (OR) tests. In the EPM and OF, CHF mice exhibited diminished exploratory behavior and motivation despite similar movement capability. In the OR, CHF mice had reduced preference for novelty and impaired short-term memory. On histology, CHF mice had unaltered overall cerebral morphology. However, analysis of gene expression by RNA-sequencing in prefrontal cortical, hippocampal, and left ventricular tissue revealed changes in genes related to inflammation and cofactors of neuronal signal transduction in CHF mice, with Nr4a1 being dysregulated both in prefrontal cortex and myocardium after MI. Conclusions: After induction of ischemic CHF, mice exhibited anhedonic behavior, decreased exploratory activity and interest in novelty, and cognitive impairment. Thus, ischemic CHF leads to distinct behavioral changes in mice analogous to symptoms observed in humans with CHF and comorbid depression. PMID:25400562
Surface De-Wetting Based Critical Heat Flux Model Development and Validation
2013-02-05
the onset of CHF. When the process of dewetting occurs at contact line and micro region, the temperature of dry spots increases, hence dryout areas...increase and the CHF occurs. Finally, we proposed the CHF mechanism based on the surface dewetting and experimental data. 15. SUBJECT TERMS spray...determines the overall heat transfer, contact line heat transfer wall is critically important to trigger the onset of CHF. When the process of dewetting
NASA Astrophysics Data System (ADS)
Ha, Minseok; Graham, Samuel
2017-08-01
Experimental studies have shown that microporous surfaces induce one of the highest enhancements in critical heat flux (CHF) during pool boiling. However, microporous surfaces may also induce a very large surface superheat (>100 °C) which is not desirable for applications such as microelectronics cooling. While the understanding of the CHF mechanism is the key to enhancing boiling heat transfer, a comprehensive understanding is not yet available. So far, three different theories for the CHF of microporous surfaces have been suggested: viscous-capillary model, hydrodynamic instability model, and dryout of the porous coatings. In general, all three theories account for some aspects of boiling phenomena. In this study, the theories are examined through their correlations with experimental data on microporous surfaces during pool boiling using deionized (DI) water. It was found that the modulation of the vapor-jet through the pore network enables a higher CHF than that of a flat surface based on the hydrodynamic instability theory. In addition, it was found that as the heat flux increases, a vapor layer grows in the porous coatings described by a simple thermal resistance model which is responsible for the large surface superheat. Once the vapor layer grows to fill the microporous structure, transition to film boiling occurs and CHF is reached. By disrupting the formation of this vapor layer through the fabrication of channels to allow vapor escape, an enhancement in the CHF and heat transfer coefficient was observed, allowing CHF greater than 3500 kW/m2 at a superheat less than 50 °C.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Mudawar, I.; Galloway, J.E.; Gersey, C.O.
Pool boiling and flow boiling were examined for near-saturated bulk conditions in order to determine the critical heat flux (CHF) trigger mechanism for each. Photographic studies of the wall region revealed features common to both situations. At fluxes below CHF, the vapor coalesces into a wavy layer which permits wetting only in wetting fronts, the portions of the liquid-vapor interface which contact the wall as a result of the interfacial waviness. Close examination of the interfacial features revealed the waves are generated from the lower edge of the heater in pool boiling and the heater`s upstream region in flow boiling.more » Wavelengths follow predictions based upon the Kelvin-Helmholtz instability criterion. Critical heat flux in both cases occurs when the pressure force exerted upon the interface due to interfacial curvature, which tends to preserve interfacial contact with the wall prior to CHF, is overcome by the momentum of vapor at the site of the first wetting front, causing the interface to lift away from the wall. It is shown this interfacial lift-off criterion facilitates accurate theoretical modeling of CHF in pool boiling and in flow boiling in both straight and curved channels.« less
Flow-Boiling Critical Heat Flux Experiments Performed in Reduced Gravity
NASA Technical Reports Server (NTRS)
Hasan, Mohammad M.; Mudawar, Issam
2005-01-01
Poor understanding of flow boiling in microgravity has recently emerged as a key obstacle to the development of many types of power generation and advanced life support systems intended for space exploration. The critical heat flux (CHF) is perhaps the most important thermal design parameter for boiling systems involving both heatflux-controlled devices and intense heat removal. Exceeding the CHF limit can lead to permanent damage, including physical burnout of the heat-dissipating device. The importance of the CHF limit creates an urgent need to develop predictive design tools to ensure both the safe and reliable operation of a two-phase thermal management system under the reduced-gravity (like that on the Moon and Mars) and microgravity environments of space. At present, very limited information is available on flow-boiling heat transfer and the CHF under these conditions.
Bubble induced flow field modulation for pool boiling enhancement over a tubular surface
NASA Astrophysics Data System (ADS)
Raghupathi, P. A.; Joshi, I. M.; Jaikumar, A.; Emery, T. S.; Kandlikar, S. G.
2017-06-01
We demonstrate the efficacy of using a strategically placed enhancement feature to modify the trajectory of bubbles nucleating on a horizontal tubular surface to increase both the critical heat flux (CHF) and the heat transfer coefficient (HTC). The CHF on a plain tube is shown to be triggered by a local dryout at the bottom of the tube due to vapor agglomeration. To mitigate this effect and delay CHF, the nucleating bubble trajectory is modified by incorporating a bubble diverter placed axially at the bottom of the tube. The nucleating bubble at the base of the diverter experiences a tangential evaporation momentum force (EMF) which causes the bubble to grow sideways away from the tube and avoid localized bubble patches that are responsible for CHF initiation. High speed imaging confirmed the lateral displacement of the bubbles away from the diverter closely matched with the theoretical predictions using EMF and buoyancy forces. Since the EMF is stronger at higher heat fluxes, bubble displacement increases with heat flux and results in the formation of separate liquid-vapor pathways wherein the liquid enters almost unobstructed at the bottom and the vapor bubble leaves sideways. Experimental results yielded CHF and HTC enhancements of ˜60% and ˜75%, respectively, with the diverter configuration when compared to a plain tube. This work can be used for guidance in developing enhancement strategies to effectively modulate the liquid-vapor flow around the heater surface at various locations to enhance HTC and CHF.
Cooling of hot bubbles by surface texture during the boiling crisis
NASA Astrophysics Data System (ADS)
Dhillon, Navdeep; Buongiorno, Jacopo; Varanasi, Kripa
2015-11-01
We report the existence of maxima in critical heat flux (CHF) enhancement for pool boiling on textured hydrophilic surfaces and reveal the interaction mechanism between bubbles and surface texture that governs the boiling crisis phenomenon. Boiling is a process of fundamental importance in many engineering and industrial applications but the maximum heat flux that can be absorbed by the boiling liquid (or CHF) is limited by the boiling crisis. Enhancing the CHF of industrial boilers by surface texturing can lead to substantial energy savings and reduction in greenhouse gas emissions on a global scale. However, the fundamental mechanisms behind this enhancement are not well understood, with some previous studies indicating that CHF should increase monotonically with increasing texture density. However, using pool boiling experiments on a parametrically designed set of plain and nano-textured micropillar surfaces, we show that there is an optimum intermediate texture density that maximizes CHF and further that the length scale of this texture is of fundamental significance. Using imbibition experiments and high-speed optical and infrared imaging, we reveal the fundamental mechanisms governing the CHF enhancement maxima in boiling crisis. We acknowledge funding from the Chevron corporation.
The behavior of vapor bubbles during boiling enhanced with acoustics and open microchannels
NASA Astrophysics Data System (ADS)
Boziuk, Thomas; Smith, Marc K.; Glezer, Ari
2012-11-01
Boiling heat transfer on a submerged heated surface is enhanced by combining a grid of surface micromachined open channels and ultrasonic acoustic actuation to control the formation and evolution of vapor bubbles and to inhibit the instability that leads to film boiling at the critical heat flux (CHF). The microchannels provide nucleation sites for vapor bubble formation and enable the entrainment of bulk subcooled fluid to these sites for sustained evaporation. Acoustic actuation excites interfacial oscillations of the detached bubbles and leads to accelerated condensation in the bulk fluid, thereby limiting the formation of vapor columns that precede the CHF instability. The combined effects of microchannels and acoustic actuation are investigated experimentally with emphasis on bubble nucleation, growth, detachment, and condensation. It is shown that this hybrid approach leads to a significant increase in the critical heat flux, a reduction of the vapor mass above the surface, and the breakup of low-frequency vapor slug formation. A large-scale model of the microchannel grid reveals details of the flow near the nucleation site and shows that the presence of the microchannels decreases the surface superheat at a given heat flux. Supported by ONR.
Predictions of Critical Heat Flux in Annular Pipes with TRACEv4.160 code
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jasiulevicius, Audrius; Macian-Juan, Rafael
2006-07-01
This paper presents the assessment of TRACE (version v4.160) against the Critical Heat Flux (CHF) experiments in annular tubes performed at the Royal Institute of Technology (KTH) in Stockholm, Sweden. The experimental database includes data for coolant mass fluxes between 250 and 2500 kg/m{sup 2}s and inlet subcooling of 10 and 40 K at a pressure of 70 bar. The work presented in this paper supplements the calculations of single round tube experiments carried out earlier and provides a broader scope of validated geometries. In addition to the Biasi and CISE-GE CHF correlations available in the code, a number ofmore » experimental points at low flow conditions are available for the annular geometry experiments, which also permitted the assessment of the Biasi/Zuber CHF correlation used in TRACE v4.160 for low flow conditions. Experiments with different axial power distribution were simulated and the effects of the axial power profile and the coolant inlet subcooling on the TRACE predictions were investigated. The results of this work show that the Biasi/Zuber correlation provides good estimation of the CHF at 70 bar, and, for the same conditions, the simulation of the annular experiments resulted in the calculation of lower CHF values compared to single-tube experiments. The analysis of the performance of the standard TRACE CHF correlations shows that the CISE-GE correlation yields critical qualities (quality at CHF) closer to the experimental values at 70 bar than the Biasi correlation for annular flow conditions. Regarding the power profile, the results of the TRACE calculations seem to be very sensitive to its shape, since, depending on the profile, different accuracies in the predictions were noted while other system conditions remained constant. The inlet coolant subcooling was also an important factor in the accuracy of TRACE CHF predictions. Thus, an increase in the inlet subcooling led to a clear improvement in the estimation of the critical quality with both Biasi and CISE-GE correlations. To complement the work, three additional CHF correlations were implemented in TRACE v4.160, namely the Bowring, Tong W-3 and Levitan-Lantsman CHF models, in order to assess the applicability of these correlations to simulate the CHF in annular tubes. The improvement of CHF predictions for low coolant mass flows (up to 1500 kg/m{sup 2}s) is noted when applying Bowring CHF correlation. However, the increase in the inlet subcooling increases the error in predicted critical quality with the Bowring correlation. The Levitan-Lantsman and Tong-W-3 correlations provide results similar to the Biasi model. Therefore, the most correct CHF predictions among the investigated correlations were obtained using CISE-GE model in the standard TRAC v4.160 code. (authors)« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yu, Dong In; Kwak, Ho Jae; Noh, Hyunwoo
Over the past several decades, phenomena related to critical heat flux (CHF) on structured surfaces have received a large amount of attention from the research community. The purpose of such research has been to enhance the safety and efficiency of a variety of thermal systems. A number of theories have been put forward to explain the key CHF enhancement mechanisms on structured surfaces. However, these theories have not been confirmed experimentally due to limitations in the available visualization techniques and the complexity of the phenomena. To overcome the limitations of the previous visualization techniques and elucidate the CHF enhancement mechanismmore » on the structured surfaces, we introduce synchrotron X-ray imaging with high spatial (~2 μm) and time (~20,000 Hz) resolutions. Lastly, this technique has enabled us to confirm that capillary-induced flow is the key CHF enhancement mechanism on structured surfaces.« less
Yu, Dong In; Kwak, Ho Jae; Noh, Hyunwoo; ...
2018-02-23
Over the past several decades, phenomena related to critical heat flux (CHF) on structured surfaces have received a large amount of attention from the research community. The purpose of such research has been to enhance the safety and efficiency of a variety of thermal systems. A number of theories have been put forward to explain the key CHF enhancement mechanisms on structured surfaces. However, these theories have not been confirmed experimentally due to limitations in the available visualization techniques and the complexity of the phenomena. To overcome the limitations of the previous visualization techniques and elucidate the CHF enhancement mechanismmore » on the structured surfaces, we introduce synchrotron X-ray imaging with high spatial (~2 μm) and time (~20,000 Hz) resolutions. Lastly, this technique has enabled us to confirm that capillary-induced flow is the key CHF enhancement mechanism on structured surfaces.« less
Critical heat flux phenomena depending on pre-pressurization in transient heat input
NASA Astrophysics Data System (ADS)
Park, Jongdoc; Fukuda, Katsuya; Liu, Qiusheng
2017-07-01
The critical heat flux (CHF) levels that occurred due to exponential heat inputs for varying periods to a 1.0-mm diameter horizontal cylinder immersed in various liquids were measured to develop an extended database on the effect of various pressures and subcoolings by photographic study. Two main mechanisms of CHF were found. One mechanism is due to the time lag of the hydrodynamic instability (HI) which starts at steady-state CHF upon fully developed nucleate boiling, and the other mechanism is due to the explosive process of heterogeneous spontaneous nucleation (HSN) which occurs at a certain HSN superheat in originally flooded cavities on the cylinder surface. The incipience of boiling processes was completely different depending on pre-pressurization. Also, the dependence of pre-pressure in transient CHFs changed due to the wettability of boiling liquids. The objective of this work is to clarify the transient CHF phenomena due to HI or HSN by photographic.
Investigation of saturated critical heat flux in a single, uniformly heated microchannel
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wojtan, Leszek; Revellin, Remi; Thome, John R.
2006-08-15
A series of tests have been performed to determine the saturated critical heat flux (CHF) in 0.5 and 0.8mm internal diameter microchannel tubes as a function of refrigerant mass velocity, heated length, saturation temperature and inlet liquid subcooling. The tested refrigerants were R-134a and R-245fa and the heated length of microchannel was varied between 20 and 70mm. The results show a strong dependence of CHF on mass velocity, heated length and microchannel diameter but no influence of liquid subcooling (2-15{sup o}C) was observed. The experimental results have been compared to the well-known CHF single-channel correlation of Y. Katto and H.more » Ohno [An improved version of the generalized correlation of critical heat flux for the forced convective boiling in uniformly heated vertical tubes, Int. J. Heat and Mass Transfer 27 (9) (1984) 1641-1648] and the multichannel correlation of W. Qu and I. Mudawar [Measurement and correlation of critical heat flux in two-phase microchannel heat sinks, Int. J. Heat and Mass Transfer 47 (2004) 2045-2059]. The comparison shows that the correlation of Katto-Ohno predicts microchannel data with a mean absolute error of 32.8% with only 41.2% of the data falling within a +/-15% error band. The correlation of Qu and Mudawar shows the same trends as the CHF data but significantly overpredicts them. Based on the present experimental data, a new microscale version of the Katto-Ohno correlation for the prediction of CHF during saturated boiling in microchannels has been proposed. (author)« less
Effect of dynamic load on water flow boiling CHF in rectangular channels
NASA Astrophysics Data System (ADS)
Zhang, Zhao; Song, Baoyin; Li, Gang; Cao, Xi
2018-06-01
Experimental investigation into flow boiling critical heat flux (CHF) characteristics in narrow rectangular channels was performed under rotating state using distilled water as working fluids. The effects of mass velocity, inlet temperature and heating orientation on CHF under dynamic load were analyzed and discussed in this paper. The results show that the dynamic load obviously influences the CHF through enhancing two-phase mixing up and bubble separating. The greater the dynamic load, the higher the CHF values. The CHF values increase with the increase of mass velocity and inlet subcooling in the experimental range. The magnitude of CHF increase with the dynamic load for bottom heating is greater than that for up heating. The present study and its newly correlation may provide some technical supports in designing the airborne vapor cycle system.
A Study of Nucleate Boiling with Forced Convection in Microgravity
NASA Technical Reports Server (NTRS)
Merte, Herman, Jr.
1999-01-01
The ultimate objective of basic studies of flow boiling in microgravity is to improve the understanding of the processes involved, as manifested by the ability to predict its behavior. This is not yet the case for boiling heat transfer even in earth gravity, despite the considerable research activity over the past 30 years. The elements that constitute the nucleate boiling process - nucleation, growth, motion, and collapse of the vapor bubbles (if the bulk liquid is subcooled) - are common to both pool and flow boiling. It is well known that the imposition of bulk liquid motion affects the vapor bubble behavior relative to pool boiling, but does not appear to significantly influence the heat transfer. Indeed, it has been recommended in the past that empirical correlations or experimental data of pool boiling be used for design purposes with forced convection nucleate boiling. It is anticipated that such will most certainly not be possible for boiling in microgravity, based on observations made with pool boiling in microgravity. In earth gravity buoyancy will act to remove the vapor bubbles from the vicinity of the heater surface regardless of how much the imposed bulk velocity is reduced, depending, of course, on the geometry of the system. Vapor bubbles have been observed to dramatically increase in size in pool boiling in microgravity, and the heat flux at which dryout took place was reduced considerably below what is generally termed the critical heat flux (CHF) in earth gravity, depending on the bulk liquid subcooling. However, at heat flux levels below dryout, the nucleate pool boiling process was enhanced considerably over that in earth gravity, in spite of the large vapor bubbles formed in microgravity and perhaps as a consequence. These large vapor bubbles tended to remain in the vicinity of the heater surface, and the enhanced heat transfer appeared to be associated with the presence of what variously has been referred to as a liquid microlayer between the bubble and the heater surface. The enhancement of the boiling process with low velocities in earth gravity for those orientations producing the formation of a liquid macrolayer described above, accompanied by "sliding" vapor bubbles, has been demonstrated. The enhancement was presented as a function of orientation, subcooling, and heated length, while a criterion for the heat transfer for mixed natural/forced convection nucleate boiling was given previously. A major unknown in the prediction and application of flow boiling heat transfer in microgravity is the upper limit of the heat flux for the onset of dryout (or critical heat flux - CHF), for given conditions of fluid-heater surfaces, including geometry, system pressure and bulk liquid subcooling. It is clearly understood that the behavior in microgravity will be no different than on earth with sufficiently high flow velocities, and would require no space experimentation. However, the boundary at which this takes place is still an unknown. Previous results of CHF measurements were presented for low velocity flow boiling at various orientations in earth gravity as a function of flow velocity and bulk liquid subcooling, along with preliminary measurements of bubble residence times on a flat heater surface. This showed promise as a parameter to be used in modeling the CHF, both in earth gravity and in microgravity. The objective of the work here is to draw attention to and show results of current modeling efforts for the CHF, with low velocities in earth gravity at different orientations and subcoolings. Many geometrical possibilities for a heater surface exist in flowing boiling, with boiling on the inner and outer surfaces of tubes perhaps being the most common. If the vapor bubble residence time on and departure size from the heater surface bear a relationship to the CHF, as results to be given indicate, it is important that visualization of and access to vapor bubble growth be conveniently available for research purposes. In addition, it is desirable to reduce the number of variables as much as possible in a fundamental study. These considerations dictated the use of a flat heater surface, which is rectangular in shape, 1.91 cm by 3.81 cm (0.75 x 1.5 inches), consisting either of a 400 Angstrom thick semi-transparent gold film sputtered on a quartz substrate which serves simultaneously as a heater and a resistance thermometer, or a copper substrate of the same size. The heater substrate is a disc which can be rotated so that the heated length in the flow direction can be changed from 1.91 to 3.81 cm (0.75 to 1.5 inches). The fluid is R-113, and the velocities can be varied between 0.5 cm/s and 60 cm/s. For a sufficiently low velocity the CHF can be modeled reasonably well at various orientations by the correlation for pool boiling corrected for the influence of bulk liquid subcooling, multiplied by the square root of q, the angle relative to horizontal. This arises from equating buoyancy and drag forces in the inverted positions where the vapor bubbles are held against the heater surface as they slide. A distortion of the measurements relative to pool boiling occurs as the flow velocity increases. In modeling this effect at different levels of subcooling it appeared appropriate to estimate the volumetric rate of vapor generation, using measurements of bubble frequency (or residence time), void fraction and average bubble boundary layer thickness. These were determined with the use of a platinum hot wire probe 0.025 mm in diameter by 1.3 mm long, applying a constant current to distinguish between contact with liquid or vapor. Two-dimensional spatial variations are obtained with a special mechanism to resolve displacements in increments of 0.025 mm. From such measurements it was determined that the fraction of the surface heat transfer resulting in evaporation varies inversely with the subcooling correction factor for the CHF. The measured inverse bubble residence time is normalized relative to that predicted for an infinite horizontal flat plate at the CHF, and is correlated well with the CHF normalized relative to that for pool boiling, for various orientation angles and subcooling levels. This correspondence is then combined with a normalizing factor for the energy flux leaving the heater surface at the CHF and the computed bubble radius at departure, determined from the balance between the outward velocity of the interface due to evaporation and the buoyance induced velocity of the center of mass of the bubble. The product of the CHF and the corresponding residence time was determined to be a constant for all orientations at a given bulk flow velocity and liquid subcooling, and must be determined empirically for each velocity and subcooling at present. It then becomes possible to predict the CHF for the different orientations, velocities, and subcoolings. These are compared with normalized measurements of the CHF for velocities ranging from 4 cm/s to 55 cm/s, subcoolings from 2.8 to 22.2 K, over orientations angles of 360 degrees.
A Novel Role of Three Dimensional Graphene Foam to Prevent Heater Failure during Boiling
Ahn, Ho Seon; Kim, Ji Min; Park, Chibeom; Jang, Ji-Wook; Lee, Jae Sung; Kim, Hyungdae; Kaviany, Massoud; Kim, Moo Hwan
2013-01-01
We report a novel boiling heat transfer (NBHT) in reduced graphene oxide (RGO) suspended in water (RGO colloid) near critical heat flux (CHF), which is traditionally the dangerous limitation of nucleate boiling heat transfer because of heater failure. When the heat flux reaches the maximum value (CHF) in RGO colloid pool boiling, the wall temperature increases gradually and slowly with an almost constant heat flux, contrary to the rapid wall temperature increase found during water pool boiling. The gained time by NBHT would provide the safer margin of the heat transfer and the amazing impact on the thermal system as the first report of graphene application. In addition, the CHF and boiling heat transfer performance also increase. This novel boiling phenomenon can effectively prevent heater failure because of the role played by the self-assembled three-dimensional foam-like graphene network (SFG). PMID:23743619
Vapor bubble evolution on a heated surface containing open microchannels
NASA Astrophysics Data System (ADS)
Forster, Christopher J.; Glezer, Ari; Smith, Marc K.
2011-11-01
Power electronics require cooling technologies capable of high heat fluxes at or below the operating temperatures of these devices. Boiling heat transfer is an effective choice for such cooling, but it is limited by the critical heat flux (CHF), which is typically near 125 W/cm2 for pool boiling of water on a flat plate at standard pressure and gravity. One method of increasing CHF is to incorporate an array of microchannels into the heated surface. Microchannels have been experimentally shown to improve CHF, and the goal of this study is to determine the primary mechanisms associated with the microchannels that allow for the increased CHF. While the use of various microstructures is not new, the emphasis of previous work has been on heat transfer aspects, as opposed to the fluid dynamics inside and in the vicinity of the microchannels. This work considers the non-isothermal fluid motion during bubble growth and departure by varying channel geometry, spacing, and heat flux input using a level-set method including vaporization and condensation. These results and the study of the underlying mechanisms will aid in the design optimization of microchannel-based cooling devices. Supported by ONR.
A scaling law for the local CHF on the external bottom side of a fully submerged reactor vessel
DOE Office of Scientific and Technical Information (OSTI.GOV)
Cheung, F.B.; Haddad, K.H.; Liu, Y.C.
1997-02-01
A scaling law for estimating the local critical heat flux on the outer surface of a heated hemispherical vessel that is fully submerged in water has been developed from the results of an advanced hydrodynamic CHF model for pool boiling on a downward facing curved heating surface. The scaling law accounts for the effects of the size of the vessel, the level of liquid subcooling, the intrinsic properties of the fluid, and the spatial variation of the local critical heat flux along the heating surface. It is found that for vessels with diameters considerably larger than the characteristic size ofmore » the vapor masses, the size effect on the local critical heat flux is limited almost entirely to the effect of subcooling associated with the local liquid head. When the subcooling effect is accounted for separately, the local CHF limit is nearly independent of the vessel size. Based upon the scaling law developed in this work, it is possible to merge, within the experimental uncertainties, all the available local CHF data obtained for various vessel sizes under both saturated and subcooled boiling conditions into a single curve. Applications of the scaling law to commercial-size vessels have been made for various system pressures and water levels above the heated vessel. Over the range of conditions explored in this study, the local CHF limit is found to increase by a factor of two or more from the bottom center to the upper edge of the vessel. Meanwhile, the critical heat flux at a given angular position of the heated vessel is also found to increase appreciably with the system pressure and the water level.« less
Dunn, F. E.; Wilson, E. H.; Feldman, E. E.; ...
2017-03-23
The conversion of the Massachusetts Institute of Technology Reactor (MITR) from the use of highly-enriched uranium (HEU) fuel-plate assemblies to low-enriched uranium (LEU) by replacing the HEU fuel plates with specially designed General Atomics (GA) uranium zirconium hydride (UZrH) LEU fuel rods is evaluated in this paper. The margin to critical heat flux (CHF) in the core, which is cooled by light water at low pressure, is evaluated analytically for steady-state operation. A form of the Groeneveld CHF lookup table method is used and described in detail. A CHF ratio of 1.41 was found in the present analysis at 10more » MW with engineering hot channel factors included. Therefore, the nominal reactor core power, and neutron flux performance, would need to be reduced by at least 25% in order to meet the regulatory requirement of a minimum CHF ratio of 2.0.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dunn, F. E.; Wilson, E. H.; Feldman, E. E.
The conversion of the Massachusetts Institute of Technology Reactor (MITR) from the use of highly-enriched uranium (HEU) fuel-plate assemblies to low-enriched uranium (LEU) by replacing the HEU fuel plates with specially designed General Atomics (GA) uranium zirconium hydride (UZrH) LEU fuel rods is evaluated in this paper. The margin to critical heat flux (CHF) in the core, which is cooled by light water at low pressure, is evaluated analytically for steady-state operation. A form of the Groeneveld CHF lookup table method is used and described in detail. A CHF ratio of 1.41 was found in the present analysis at 10more » MW with engineering hot channel factors included. Therefore, the nominal reactor core power, and neutron flux performance, would need to be reduced by at least 25% in order to meet the regulatory requirement of a minimum CHF ratio of 2.0.« less
2002-12-01
surface temperature for a given heat flux [2]. Mudawar and Valentine conducted an experimental study of spray cooling to determine local quenching... Mudawar presented a CHF correlation with suitable dimensionless parameters that accurately predicted data for FC-72, FC-87 and water [5]. The 2...correlation by Estes and Mudawar had a strong dependence of CHF on volumetric flux and Sauter mean diameter. Sehmbey et al. developed a semiempirical
DOE Office of Scientific and Technical Information (OSTI.GOV)
Buongiorno, Jacopo; Hu, Lin-wen
2009-07-31
Nanofluids are colloidal dispersions of nanoparticles in water. Many studies have reported very significant enhancement (up to 200%) of the Critical Heat Flux (CHF) in pool boiling of nanofluids (You et al. 2003, Vassallo et al. 2004, Bang and Chang 2005, Kim et al. 2006, Kim et al. 2007). These observations have generated considerable interest in nanofluids as potential coolants for more compact and efficient thermal management systems. Potential Light Water Reactor applications include the primary coolant, safety systems and severe accident management strategies, as reported in other papers (Buongiorno et al. 2008 and 2009). However, the situation of interestmore » in reactor applications is often flow boiling, for which no nanofluid data have been reported so far. In this project we investigated the potential of nanofluids to enhance CHF in flow boiling. Subcooled flow boiling heat transfer and CHF experiments were performed with low concentrations of alumina, zinc oxide, and diamond nanoparticles in water (≤ 0.1 % by volume) at atmospheric pressure. It was found that for comparable test conditions the values of the nanofluid and water heat transfer coefficient (HTC) are similar (within ±20%). The HTC increased with mass flux and heat flux for water and nanofluids alike, as expected in flow boiling. The CHF tests were conducted at 0.1 MPa and at three different mass fluxes (1500, 2000, 2500 kg/m2s) under subcooled conditions. The maximum CHF enhancement was 53%, 53% and 38% for alumina, zinc oxide and diamond, respectively, always obtained at the highest mass flux. A post-mortem analysis of the boiling surface reveals that its morphology is altered by deposition of the particles during nanofluids boiling. A confocal-microscopy-based examination of the test section revealed that nanoparticles deposition not only changes the number of micro-cavities on the surface, but also the surface wettability. A simple model was used to estimate the ensuing nucleation site density changes, but no definitive correlation between the nucleation site density and the heat transfer coefficient data could be found. Wettability of the surface was substantially increased for heater coupons boiled in alumina and zinc oxide nanofluids, and such wettability increase seems to correlate reasonably well with the observed marked CHF enhancement for the respective nanofluids. Interpretation of the experimental data was conducted in light of the governing surface parameters (surface area, contact angle, roughness, thermal conductivity) and existing models. It was found that no single parameter could explain the observed HTC or CHF phenomena.« less
Spray cooling characteristics of nanofluids for electronic power devices.
Hsieh, Shou-Shing; Leu, Hsin-Yuan; Liu, Hao-Hsiang
2015-01-01
The performance of a single spray for electronic power devices using deionized (DI) water and pure silver (Ag) particles as well as multi-walled carbon nanotube (MCNT) particles, respectively, is studied herein. The tests are performed with a flat horizontal heated surface using a nozzle diameter of 0.5 mm with a definite nozzle-to-target surface distance of 25 mm. The effects of nanoparticle volume fraction and mass flow rate of the liquid on the surface heat flux, including critical heat flux (CHF), are explored. Both steady state and transient data are collected for the two-phase heat transfer coefficient, boiling curve/ cooling history, and the corresponding CHF. The heat transfer removal rate can reach up to 274 W/cm(2) with the corresponding CHF enhancement ratio of 2.4 for the Ag/water nanofluids present at a volume fraction of 0.0075% with a low mass flux of 11.9 × 10(-4) kg/cm(2)s.
Investigation of Body Force Effects on Flow Boiling Critical Heat Flux
NASA Technical Reports Server (NTRS)
Zhang, Hui; Mudawar, Issam; Hasan, Mohammad M.
2002-01-01
The bubble coalescence and interfacial instabilities that are important to modeling critical heat flux (CHF) in reduced-gravity systems can be sensitive to even minute body forces. Understanding these complex phenomena is vital to the design and safe implementation of two-phase thermal management loops proposed for space and planetary-based thermal systems. While reduced gravity conditions cannot be accurately simulated in 1g ground-based experiments, such experiments can help isolate the effects of the various forces (body force, surface tension force and inertia) which influence flow boiling CHF. In this project, the effects of the component of body force perpendicular to a heated wall were examined by conducting 1g flow boiling experiments at different orientations. FC-72 liquid was boiled along one wall of a transparent rectangular flow channel that permitted photographic study of the vapor-liquid interface at conditions approaching CHF. High-speed video imaging was employed to capture dominant CHF mechanisms. Six different CHF regimes were identified: Wavy Vapor Layer, Pool Boiling, Stratification, Vapor Counterflow, Vapor Stagnation, and Separated Concurrent Vapor Flow. CHF showed great sensitivity to orientation for flow velocities below 0.2 m/s, where very small CHF values where measured, especially with downflow and downward-facing heated wall orientations. High flow velocities dampened the effects of orientation considerably. Figure I shows representative images for the different CHF regimes. The Wavy Vapor Layer regime was dominant for all high velocities and most orientations, while all other regimes were encountered at low velocities, in the downflow and/or downward-facing heated wall orientations. The Interfacial Lift-off model was modified to predict the effects of orientation on CHF for the dominant Wavy Vapor Layer regime. The photographic study captured a fairly continuous wavy vapor layer travelling along the heated wall while permitting liquid contact only in wetting fronts, located in the troughs of the interfacial waves. CHF commenced when wetting fronts near the outlet were lifted off the wall. The Interfacial Lift-off model is shown to be an effective tool for predicting the effects of body force on CHF at high velocities.
Criticality in the slowed-down boiling crisis at zero gravity.
Charignon, T; Lloveras, P; Chatain, D; Truskinovsky, L; Vives, E; Beysens, D; Nikolayev, V S
2015-05-01
Boiling crisis is a transition between nucleate and film boiling. It occurs at a threshold value of the heat flux from the heater called CHF (critical heat flux). Usually, boiling crisis studies are hindered by the high CHF and short transition duration (below 1 ms). Here we report on experiments in hydrogen near its liquid-vapor critical point, in which the CHF is low and the dynamics slow enough to be resolved. As under such conditions the surface tension is very small, the experiments are carried out in the reduced gravity to preserve the conventional bubble geometry. Weightlessness is created artificially in two-phase hydrogen by compensating gravity with magnetic forces. We were able to reveal the fractal structure of the contour of the percolating cluster of the dry areas at the heater that precedes the boiling crisis. We provide a direct statistical analysis of dry spot areas that confirms the boiling crisis at zero gravity as a scale-free phenomenon. It was observed that, in agreement with theoretical predictions, saturated boiling CHF tends to zero (within the precision of our thermal control system) in zero gravity, which suggests that the boiling crisis may be observed at any heat flux provided the experiment lasts long enough.
NASA Astrophysics Data System (ADS)
Yang, Jun
Nucleate boiling is a well-recognized means for passively removing high heat loads (up to ˜106 W/m2) generated by a molten reactor core under severe accident conditions while maintaining relatively low reactor vessel temperature (<800 °C). With the upgrade and development of advanced power reactors, however, enhancing the nucleate boiling rate and its upper limit, Critical Heat Flux (CHF), becomes the key to the success of external passive cooling of reactor vessel undergoing core disrupture accidents. In the present study, two boiling heat transfer enhancement methods have been proposed, experimentally investigated and theoretically modelled. The first method involves the use of a suitable surface coating to enhance downward-facing boiling rate and CHF limit so as to substantially increase the possibility of reactor vessel surviving high thermal load attack. The second method involves the use of an enhanced vessel/insulation design to facilitate the process of steam venting through the annular channel formed between the reactor vessel and the insulation structure, which in turn would further enhance both the boiling rate and CHF limit. Among the various available surface coating techniques, metallic micro-porous layer surface coating has been identified as an appropriate coating material for use in External Reactor Vessel Cooling (ERVC) based on the overall consideration of enhanced performance, durability, the ease of manufacturing and application. Since no previous research work had explored the feasibility of applying such a metallic micro-porous layer surface coating on a large, downward facing and curved surface such as the bottom head of a reactor vessel, a series of characterization tests and experiments were performed in the present study to determine a suitable coating material composition and application method. Using the optimized metallic micro-porous surface coatings, quenching and steady-state boiling experiments were conducted in the Sub-scale Boundary Layer Boiling (SBLB) test facility at Penn State to investigate the nucleate boiling and CHF enhancement effects of the surface coatings by comparing the measurements with those for a plain vessel without coatings. An overall enhancement in nucleate boiling rates and CHF limits up to 100% were observed. Moreover, combination of data from quenching experiments and steady-state experiments produced new sets of boiling curves, which covered both the nucleate and transient boiling regimes with much greater accuracy. Beside the experimental work, a theoretical CHF model has also been developed by considering the vapor dynamics and the boiling-induced two-phase motions in three separate regions adjacent to the heating surface. The CHF model is capable of predicting the performance of micro-porous coatings with given particle diameter, porosity, media permeability and thickness. It is found that the present CHF model agrees favorably with the experimental data. Effects of an enhanced vessel/insulation structure on the local nucleate boiling rate and CHF limit have also been investigated experimentally. It is observed that the local two-phase flow quantities such as the local void fraction, quality, mean vapor velocity, mean liquid velocity, and mean vapor and liquid mass flow rates could have great impact on the local surface heat flux as boiling of water takes place on the vessel surface. An upward co-current two-phase flow model has been developed to predict the local two-phase flow behavior for different flow channel geometries, which are set by the design of insulation structures. It is found from the two-phase flow visualization experiments and the two-phase flow model calculations that the enhanced vessel/insulation structure greatly improved the steam venting process at the minimum gap location compared to the performance of thermal insulation structures without enhancement. Moveover, depending on the angular location, steady-state boiling experiments with the enhanced insulation design showed an enhancement of 1.8 to 3.0 times in the local critical heat flux. Finally, nucleate boiling and CHF correlations were developed based on the data obtained from various quenching and steady-state boiling experiments. Additionally, CHF enhancement factors were determined and examined to show the separate and integral effects of the two ERVC enhancement methods. When both vessel coating and insulation structure were used simultaneously, the integral effect on CHF enhancement was found much less than the product of the two separate effects, indicating possible competing mechanisms (i.e., interference) between the two enhancement methods.
NASA Astrophysics Data System (ADS)
Zhang, Yonghai; Liu, Bin; Zhao, Jianfu; Deng, Yueping; Wei, Jinjia
2018-06-01
The flow boiling heat transfer characteristics of subcooled air-dissolved FC-72 on a smooth surface (chip S) were studied in microgravity by utilizing the drop tower facility in Beijing. The heater, with dimensions of 40 × 10 × 0.5 mm3 (length × width × thickness), was combined with two silicon chips with the dimensions of 20 × 10 × 0.5 mm3. High-speed visualization was used to supplement observation in the heat transfer and vapor-liquid two-phase flow characteristics. In the low and moderate heat fluxes region, the flow boiling of chip S at inlet velocity V = 0.5 m/s shows almost the same regulations as that in pool boiling. All the wall temperatures at different positions along the heater in microgravity are slightly lower than that in normal gravity, which indicates slight heat transfer enhancement. However, in the high heat flux region, the pool boiling of chip S shows much evident deterioration of heat transfer compared with that of flow boiling in microgravity. Moreover, the bubbles of flow boiling in microgravity become larger than that in normal gravity due to the lack of buoyancy Although the difference of the void fraction in x-y plain becomes larger with increasing heat flux under different gravity levels, it shows nearly no effect on heat transfer performance except for critical heat flux (CHF). Once the void fraction in y-z plain at the end of the heater equals 1, the vapor blanket will be formed quickly and transmit from downstream to upstream along the heater, and CHF occurs. Thus, the height of channel is an important parameter to determine CHF in microgravity at a fixed velocity. The flow boiling of chip S at inlet velocity V = 0.5 m/s shows higher CHF than that of pool boiling because of the inertia force, and the CHF under microgravity is about 78-92% of that in normal gravity.
A formal approach for the prediction of the critical heat flux in subcooled water
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lombardi, C.
1995-09-01
The critical heat flux (CHF) in subcooled water at high mass fluxes are not yet satisfactory correlated. For this scope a formal approach is here followed, which is based on an extension of the parameters and the correlation used for the dryout prediction for medium high quality mixtures. The obtained correlation, in spite of its simplicity and its explicit form, yields satisfactory predictions, also when applied to more conventional CHF data at low-medium mass fluxes and high pressures. Further improvements are possible, if a more complete data bank will be available. The main and general open item is the definitionmore » of a criterion, depending only on independent parameters, such as mass flux, pressure, inlet subcooling and geometry, to predict whether the heat transfer crisis will result as a DNB or a dryout phenomenon.« less
Flow Boiling Critical Heat Flux in Reduced Gravity
NASA Technical Reports Server (NTRS)
Mudawar, Issam; Zhang, Hui; Hasan, Mohammad M.
2004-01-01
This study provides systematic method for reducing power consumption in reduced gravity systems by adopting minimum velocity required to provide adequate CHF and preclude detrimental effects of reduced gravity . This study proves it is possible to use existing 1 ge flow boiling and CHF correlations and models to design reduced gravity systems provided minimum velocity criteria are met
Ultrahigh Flux Thin Film Boiling Heat Transfer Through Nanoporous Membranes.
Wang, Qingyang; Chen, Renkun
2018-05-09
Phase change heat transfer is fundamentally important for thermal energy conversion and management, such as in electronics with power density over 1 kW/cm 2 . The critical heat flux (CHF) of phase change heat transfer, either evaporation or boiling, is limited by vapor flux from the liquid-vapor interface, known as the upper limit of heat flux. This limit could in theory be greater than 1 kW/cm 2 on a planar surface, but its experimental realization has remained elusive. Here, we utilized nanoporous membranes to realize a new "thin film boiling" regime that resulted in an unprecedentedly high CHF of over 1.2 kW/cm 2 on a planar surface, which is within a factor of 4 of the theoretical limit, and can be increased to a higher value if mechanical strength of the membranes can be improved (demonstrated with 1.85 kW/cm 2 CHF in this work). The liquid supply is achieved through a simple nanoporous membrane that supports the liquid film where its thickness automatically decreases as heat flux increases. The thin film configuration reduces the conductive thermal resistance, leads to high frequency bubble departure, and provides separate liquid-vapor pathways, therefore significantly enhances the heat transfer. Our work provides a new nanostructuring approach to achieve ultrahigh heat flux in phase change heat transfer and will benefit both theoretical understanding and application in thermal management of high power devices of boiling heat transfer.
New model for burnout prediction in channels of various cross-section
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bobkov, V.P.; Kozina, N.V.; Vinogrado, V.N.
1995-09-01
The model developed to predict a critical heat flux (CHF) in various channels is presented together with the results of data analysis. A model is the realization of relative method of CHF describing based on the data for round tube and on the system of correction factors. The results of data description presented here are for rectangular and triangular channels, annuli and rod bundles.
León, Laura A.; Castro-Gomes, Vitor; Zárate-Guerrero, Santiago; Corredor, Karen; Mello Cruz, Antonio P.; Brandão, Marcus L.; Cardenas, Fernando P.; Landeira-Fernandez, J.
2017-01-01
The role of serotonin (5-hydroxytryptamine [5-HT]) and 5-HT2A receptors in anxiety has been extensively studied, mostly without considering individual differences in trait anxiety. Our laboratory developed two lines of animals that are bred for high and low freezing responses to contextual cues that are previously associated with footshock (Carioca High-conditioned Freezing [CHF] and Carioca Low-conditioned Freezing [CLF]). The present study investigated whether ketanserin, a preferential 5-HT2A receptor blocker, exerts distinct anxiety-like profiles in these two lines of animals. In the first experiment, the animals received a systemic injection of ketanserin and were exposed to the elevated plus maze (EPM). In the second experiment, these two lines of animals received microinjections of ketanserin in the infralimbic (IL) and prelimbic (PL) cortices and were exposed to either the EPM or a contextual fear conditioning paradigm. The two rat lines exhibited bidirectional effects on anxiety-like behavior in the EPM and opposite responses to ketanserin. Both systemic and intra-IL cortex injections of ketanserin exerted anxiolytic-like effects in CHF rats but anxiogenic-like effects in CLF rats. Microinjections of ketanserin in the PL cortex also exerted anxiolytic-like effects in CHF rats but had no effect in CLF rats. These results suggest that the behavioral effects of 5-HT2A receptor antagonism might depend on genetic variability associated with baseline reactions to threatening situations and 5-HT2A receptor expression in the IL and PL cortices. Highlights -CHF and CLF rats are two bidirectional lines that are based on contextual fear conditioning.-CHF rats have a more “anxious” phenotype than CLF rats in the EPM.-The 5-HT2A receptor antagonist ketanserin had opposite behavioral effects in CHF and CLF rats.-Systemic and IL injections either decreased (CHF) or increased (CLF) anxiety-like behavior.-PL injections either decreased (CHF) anxiety-like behavior or had no effect (CLF). PMID:28736518
Ahn, Ho Seon; Kim, Jin Man; Kim, TaeJoo; Park, Su Cheong; Kim, Ji Min; Park, Youngjae; Yu, Dong In; Hwang, Kyoung Won; Jo, HangJin; Park, Hyun Sun; Kim, Hyungdae; Kim, Moo Hwan
2014-01-01
Boiling heat transfer (BHT) is a particularly efficient heat transport method because of the latent heat associated with the process. However, the efficiency of BHT decreases significantly with increasing wall temperature when the critical heat flux (CHF) is reached. Graphene has received much recent research attention for applications in thermal engineering due to its large thermal conductivity. In this study, graphene films of various thicknesses were deposited on a heated surface, and enhancements of BHT and CHF were investigated via pool-boiling experiments. In contrast to the well-known surface effects, including improved wettability and liquid spreading due to micron- and nanometer-scale structures, nanometer-scale folded edges of graphene films provided a clue of BHT improvement and only the thermal conductivity of the graphene layer could explain the dependence of the CHF on the thickness. The large thermal conductivity of the graphene films inhibited the formation of hot spots, thereby increasing the CHF. Finally, the provided empirical model could be suitable for prediction of CHF. PMID:25182076
Critical heat flux for free convection boiling in thin rectangular channels
DOE Office of Scientific and Technical Information (OSTI.GOV)
Cheng, Lap Y.; Tichler, P.R.
A review of the experimental data on free convection boiling critical heat flux (CHF) in vertical rectangular channels reveals three mechanisms of burnout. They are the pool boiling limit, the circulation limit, and the flooding limit associated with a transition in flow regime from churn to annular flow. The dominance of a particular mechanism depends on the dimensions of the channel. Analytical models were developed for each free convection boiling limit. Limited agreement with data is observed. A CHF correlation, which is valid for a wide range of gap sizes, was constructed from the CHFs calculated according to the threemore » mechanisms of burnout. 17 refs., 7 figs.« less
Self-care and depression in patients with chronic heart failure.
Holzapfel, Nicole; Löwe, Bernd; Wild, Beate; Schellberg, Dieter; Zugck, Christian; Remppis, Andrew; Katus, Hugo A; Haass, Markus; Rauch, Bernhard; Jünger, Jana; Herzog, Wolfgang; Müller-Tasch, Thomas
2009-01-01
Although chronic heart failure (CHF) is often complicated by comorbid depression and poor self-care, little is known about their specific association in patients with CHF. To investigate self-care behavior among patients with CHF with different degrees of depression severity. A total of 287 patients with documented CHF, New York Heart Association functional class II to IV, completed the European Heart Failure Self-Care Behavior Scale. The Structured Clinical Interview for DSM (SCID) IV served as the criterion standard for the presence of a depressive disorder. Analyses of covariance and linear regression analyses revealed that patients with CHF with minor depression reported significantly lower levels of self-care than patients with major depression (P = .003) and nondepressed patients (P = .014). In addition to minor depression, age (P < or = .001), multimorbidity (P = .01), left ventricular ejection fraction (P = .001), and family status (P = .01) were determinants of self-care. Our results demonstrate that patients with CHF with minor depression and not major depression are at higher risk for poor self-care and its resulting consequences, such as symptom deterioration and frequent hospitalization.
2013-09-01
heat transfer coefficients due to the high heat of vapor- ization. Many authors ([ Mudawar (2001)], [ Mudawar and Bowers (1999)] and [Kandlikar (2005...Letters, 95, (2005), 1. [Rosales and Meneveau (2006)] C. Rosales and C. Meneveau. Physics of Fluids, 18, (2006), 075104. [ Mudawar and Bowers (1999)] I... Mudawar and M.B. Bowers, Ultra-high crit- ical heat flux (CHF) for subcooled water flow boiling-I: CHF data and parametric effects for small
NASA Astrophysics Data System (ADS)
Shibahara, Makoto; Fukuda, Katsuya; Liu, Qiusheng; Hata, Koichi
2018-02-01
The heat transfer characteristics of forced convection for subcooled water in small tubes were clarified using the commercial computational fluid dynamic (CFD) code, PHENICS ver. 2013. The analytical model consists of a platinum tube (the heated section) and a stainless tube (the non-heated section). Since the platinum tube was heated by direct current in the authors' previous experiments, a uniform heat flux with the exponential function was given as a boundary condition in the numerical simulation. Two inner diameters of the tubes were considered: 1.0 and 2.0 mm. The upward flow velocities ranged from 2 to 16 m/s and the inlet temperature ranged from 298 to 343 K. The numerical results showed that the difference between the surface temperature and the bulk temperature was in good agreement with the experimental data at each heat flux. The numerical model was extended to the liquid sublayer analysis for the CHF prediction and was evaluated by comparing its results with the experimental data. It was postulated that the CHF occurs when the fluid temperature near the heated wall exceeds the saturated temperature, based on Celata et al.'s superheated layer vapor replenishment (SLVR) model. The suggested prediction method was in good agreement with the experimental data and with other CHF data in literature within ±25%.
Transient boiling in two-phase helium natural circulation loops
NASA Astrophysics Data System (ADS)
Furci, H.; Baudouy, B.; Four, A.; Meuris, C.
2014-01-01
Two-phase helium natural circulation loops are used for cooling large superconducting magnets, as CMS for LHC. During normal operation or in the case of incidents, transients are exerted on the cooling system. Here a cooling system of this type is studied experimentally. Sudden power changes are operated on a vertical-heated-section natural convection loop, simulating a fast increase of heat deposition on magnet cooling pipes. Mass flow rate, heated section wall temperature and pressure drop variations are measured as a function of time, to assess the time behavior concerning the boiling regime according to the values of power injected on the heated section. The boiling curves and critical heat flux (CHF) values have been obtained in steady state. Temperature evolution has been observed in order to explore the operating ranges where heat transfer is deteriorated. Premature film boiling has been observed during transients on the heated section in some power ranges, even at appreciably lower values than the CHF. A way of attenuating these undesired temperature excursions has been identified through the application of high enough initial heating power.
Spray Cooling Trajectory Angle Impact Upon Heat Flux Using a Straight Finned Enhanced Surface
NASA Technical Reports Server (NTRS)
Silk, Eric A.; Kim, Jungho; Kiger, Ken
2005-01-01
Experiments were conducted to study the effects of spray trajectory angles upon heat flux for flat and enhanced surface spray cooling. The surface enhancement consisted of straight fins machined on the top surface of a copper heater block. Spray cooling curves were obtained with the straight fin surface aligned both parallel (axial) and perpendicular (transverse) to the spray axis. Measurements were also obtained on a flat surface heater block for comparison purposes. Each copper block had a cross-sectional area of 2.0 sq cm. A 2x2 nozzle array was used with PF-5060 as the working fluid. Thermal performance data was obtained under nominally degassed (chamber pressure of 41.4 kPa) conditions. Results show that the maximum CHF in all cases was attained for a trajectory angle of 30' from the surface normal. Furthermore, trajectory angles applied to straight finned surfaces can have a critical heat flux (CHF) enhancement as much as 75% (heat flux value of 140 W/sq cm) relative to the vertical spray orientation for the analogous flat surface case under nominally degassed conditions.
Steady-State Thermal-Hydraulics Analyses for the Conversion of BR2 to Low Enriched Uranium Fuel
DOE Office of Scientific and Technical Information (OSTI.GOV)
Licht, J.; Bergeron, A.; Dionne, B.
The code PLTEMP/ANL version 4.2 was used to perform the steady-state thermal-hydraulic analyses of the BR2 research reactor for conversion from Highly-Enriched to Low Enriched Uranium fuel (HEU and LEU, respectively). Calculations were performed to evaluate different fuel assemblies with respect to the onset of nucleate boiling (ONB), flow instability (FI), critical heat flux (CHF) and fuel temperature at beginning of cycle conditions. The fuel assemblies were characteristic of fresh fuel (0% burnup), highest heat flux (16% burnup), highest power (32% burnup) and highest burnup (46% burnup). Results show that the high heat flux fuel element is limiting for ONB,more » FI, and CHF, for both HEU and LEU fuel, but that the high power fuel element produces similar margin in a few cases. The maximum fuel temperature similarly occurs in both the high heat flux and high power fuel assemblies for both HEU and LEU fuel. A sensitivity study was also performed to evaluate the variation in fuel temperature due to uncertainties in the thermal conductivity degradation associated with burnup.« less
High heat flux burnout in subcooled flow boiling
NASA Astrophysics Data System (ADS)
Celata, G. P.; Cumo, M.; Mariani, A.
1995-09-01
The paper reports the results of an experimental research carried out at the Heat Transfer Division of the Energy Department, C.R. Casaccia, on the thermal hydraulic characterization of subcooled flow boiling CHF under typical conditions of thermonuclear fusion reactors, i.e. high liquid velocity and subcooling. The experiment was carried out exploring the following parameters: channel diameter (from 2.5 to 8.0 mm), heated length (10 and 15 cm), liquid velocity (from 2 to 40 m/s), exit pressure (from atmospheric to 5.0 MPa), inlet temperature (from 30 to 80 °C), channel orientation (vertical and horizontal). A maximum CHF value of 60.6 MW/m2 has been obtained under the following conditions: T in=30°, p=2.5 MPa, u=40 m/s, D=2.5 mm (smooth channel) Turbulence promoters (helically coiled wires) have been employed to further enhance the CHF attainable with subcooled flow boiling. Helically coiled wires allow an increase of 50% of the maximum CHF obtained with smooth channels.
Critical Heat Flux in Pool Boiling on Metal-Graphite Composite Surfaces
NASA Technical Reports Server (NTRS)
Zhang, Nengli; Yang, Wen-Jei; Chao, David F.; Chao, David F. (Technical Monitor)
2000-01-01
A study is conducted on high heat-flux pool boiling of pentane on micro-configured composite surfaces. The boiling surfaces are copper-graphite (Cu-Gr) and aluminum-graphite (Al-Gr) composites with a fiber volume concentration of 50%. The micro-graphite fibers embedded in the matrix contribute to a substantial enhancement in boiling heat-transfer performance. Correlation equations are obtained for both the isolated and coalesced bubble regimes, utilizing a mathematical model based on a metal-graphite, two-tier configuration with the aid of experimental data. A new model to predict the critical heat flux (CHF) on the composites is proposed to explain the fundamental aspects of the boiling phenomena. Three different factors affecting the CHF are considered in the model. Two of them are expected to become the main agents driving vapor volume detachment under microgravity conditions, using the metal-graphite composite surfaces as the heating surface and using liquids with an unusual Marangoni effect as the working fluid.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Brown, Nicholas R.; Wysocki, Aaron J.; Terrani, Kurt A.
The U.S. Department of Energy Office of Nuclear Energy (DOE-NE) Advanced Fuels Campaign (AFC) is working closely with the nuclear industry to develop fuel and cladding candidates with potentially enhanced accident tolerance, also known as accident tolerant fuel (ATF). Thermal-fluids characteristics are a vital element of a holistic engineering evaluation of ATF concepts. One vital characteristic related to boiling heat transfer is the critical heat flux (CHF). CHF plays a vital role in determining safety margins during normal operation and also in the progression of potential transient or accident scenarios. This deliverable is a scoping survey of thermal-fluids evaluation andmore » confirmatory experimental validation requirements of accident tolerant cladding concepts with a focus on boiling heat transfer characteristics. The key takeaway messages of this report are: 1. CHF prediction accuracy is important and the correlations may have significant uncertainty. 2. Surface conditions are important factors for CHF, primarily the wettability that is characterized by contact angle. Smaller contact angle indicates greater wettability, which increases the CHF. Surface roughness also impacts wettability. Results in the literature for pool boiling experiments indicate changes in CHF by up to 60% for several ATF cladding candidates. 3. The measured wettability of FeCrAl (i.e., contact angle and roughness) indicates that CHF should be investigated further through pool boiling and flow boiling experiments. 4. Initial measurements of static advancing contact angle and surface roughness indicate that FeCrAl is expected to have a higher CHF than Zircaloy. The measured contact angle of different FeCrAl alloy samples depends on oxide layer thickness and composition. The static advancing contact angle tends to decrease as the oxide layer thickness increases.« less
Metzler, Dominik; Li, Chen; Engelmann, Sebastian; ...
2015-11-11
The need for atomic layer etching (ALE) is steadily increasing as smaller critical dimensions and pitches are required in device patterning. A flux-control based cyclic Ar/C 4F 8 ALE based on steady-state Ar plasma in conjunction with periodic, precise C 4F 8 injection and synchronized plasma-based low energy Ar + ion bombardment has been established for SiO 2. 1 In this work, the cyclic process is further characterized and extended to ALE of silicon under similar process conditions. The use of CHF 3 as a precursor is examined and compared to C 4F 8. CHF 3 is shown to enablemore » selective SiO 2/Si etching using a fluorocarbon (FC) film build up. Other critical process parameters investigated are the FC film thickness deposited per cycle, the ion energy, and the etch step length. Etching behavior and mechanisms are studied using in situ real time ellipsometry and X-ray photoelectron spectroscopy. Silicon ALE shows less self-limitation than silicon oxide due to higher physical sputtering rates for the maximum ion energies used in this work, ranged from 20 to 30 eV. The surface chemistry is found to contain fluorinated silicon oxide during the etching of silicon. As a result, plasma parameters during ALE are studied using a Langmuir probe and establish the impact of precursor addition on plasma properties.« less
Patron, Elisabetta; Messerotti Benvenuti, Simone; Lopriore, Vincenzo; Aratari, Jenny; Palomba, Daniela
Depression has been associated with poor health-related quality of life (HRQoL) in patients with congestive heart failure (CHF). However, to date, whether somatic-affective and cognitive-depressive symptoms differently contribute to poor HRQoL and behavioral functional capacity in patients with CHF has yet to be investigated. To examine the differential influence of somatic-affective vs cognitive-depressive symptoms on HRQoL and behavioral functional capacity in CHF patients. Overall, 55 patients with CHF completed a psychologic evaluation, including the Minnesota Living with Heart Failure Questionnaire, the Beck Depression Inventory-II, and the Beck Anxiety Inventory for HRQoL, depressive, and anxiety symptoms, respectively. The patients completed the Instrumental Activities of Daily Living Questionnaire and the 6-minute walk test for behavioral functional capacity. Hierarchical regression analyses were used to predict HRQoL and behavioral functional capacity from Beck Depression Inventory-II and Beck Anxiety Inventory scores. Somatic-affective depressive symptoms were associated with physical (β = 0.37, p = 0.005) and emotional (β = 0.39, p = 0.008) Minnesota Living with Heart Failure Questionnaire subscale scores. Likewise, somatic-affective depressive symptoms predicted Instrumental Activities of Daily Livings Scores (β = 0.43, p = 0.004) and distance ambulated during the 6-minute walk test (β = -0.36, p = 0.029). By contrast, cognitive-depressive symptoms and anxiety were unrelated to HRQoL and behavioral functional capacity (all p > 0.05). These findings showed that somatic-affective depressive symptoms, but not cognitive-depressive symptoms and anxiety, are associated with poor HRQoL and behavioral functional capacity independent of age, clinical functional status, and medical comorbidities. This study suggests that patients with CHF with somatic-affective rather than cognitive-depressive symptoms or anxiety may be at greater risk of poor HRQoL and behavioral functional capacity. Copyright © 2017 The Academy of Psychosomatic Medicine. Published by Elsevier Inc. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bucci, Matteo; Seong, Jee H.; Buongiorno, Jdacopo
Here we report on MIT’s THM work in Q4 2016 and Q1 2017. The goal of this project is to design, construct and execute tests of flow boiling critical heat flux (CHF) at high-pressure using high-resolution and high-speed video and infrared (IR) thermometry, to generate unique data to inform the development of and validate mechanistic boiling heat transfer and CHF models. In FY2016, a new test section was designed and fabricated. Data was collected at atmospheric conditions at 10, 25 and 50 K subcoolings, and three mass fluxes, i.e. 500, 750 and 1000 kg/m2/s. Starting in Q4 2016 and continuingmore » forward, new post-processing techniques have been developed to analyze the data collected. These new algorithms analyze the time-dependent temperature and heat flux distributions to calculate nucleation site density, nucleation frequency, growth and wait time, dry area fraction, and the complete heat flux partitioning. In Q1 2017 a new flow boiling loop was designed and constructed to support flow boiling tests up 10 bar pressure and 180 °C. Initial shakedown and testing has been completed. The flow loop and test section are now ready to begin high-pressure flow boiling testing.« less
Nolan, Robert P; Payne, Ada Ym; Ross, Heather; White, Michel; D'Antono, Bianca; Chan, Sammy; Barr, Susan I; Gwadry-Sridhar, Femida; Nigam, Anil; Perreault, Sylvie; Farkouh, Michael; McDonald, Michael; Goodman, Jack; Thomas, Scott; Zieroth, Shelley; Isaac, Debra; Oh, Paul; Rajda, Miroslaw; Chen, Maggie; Eysenbach, Gunther; Liu, Sam; Zbib, Ahmad
2014-01-30
Chronic heart failure (CHF) is a public health priority. Its age-standardized prevalence has increased over the past decade. A major challenge for the management of CHF is to promote long-term adherence to self-care behaviors without overtaxing available health care resources. Counseling by multidisciplinary health care teams helps to improve adherence to self-care behaviors and to reduce the rate of death and hospitalization. In the absence of intervention, adherence to self-care is below recommended standards. This trial aims to establish and evaluate a Canadian e-platform that will provide a core, standardized protocol of behavioral counseling and education to facilitate long-term adherence to self-care among patients with CHF. Canadian e-Platform to Promote Behavioral Self-Management in Chronic Heart Failure (CHF-CePPORT) is a multi-site, double blind, randomized controlled trial with a 2 parallel-group (e-Counseling + Usual Care vs e-Info Control + Usual Care) by 3 assessments (baseline, 4-, and 12-month) design. We will identify subjects with New York Heart Association Class II or III systolic heart failure from collaborating CHF clinics and then recruit them (n=278) by phone. Subjects will be randomized in blocks within each site (Toronto, Montreal, and Vancouver). The primary outcome will be improved quality of life, defined as an increased number of subjects with an improvement of ≥5 points on the summary score of the Kansas City Cardiomyopathy Questionnaire. We will also assess the following secondary outcomes: (1) diet habits, depression, anxiety, smoking history, stress level, and readiness for change using self-report questionnaires, (2) physical activity level, current smoking status, and vagal-heart rate modulation by physiological tests, and (3) exercise capacity, prognostic indicators of cardiovascular functioning, and medication adherence through medical chart review. The primary outcome will be analyzed using generalized estimation equations with repeated measures on an intention-to-treat basis. Secondary outcomes will be analyzed using repeated-measures linear mixed models with a random effects intercept. All significant main effects or interactions in the statistical models will be followed up with post hoc contrasts using a Bonferroni correction with a 2-sided statistical significance criterion of P<.05. This 3.5-year, proof-of-principle trial will establish the e-infrastructure for a pan-Canadian e-platform for CHF that is comprised of a standardized, evidence-based protocol of e-Counseling. CHF-CePPORT is designed to improve long-term adherence to self-care behaviors and quality of life among patients with CHF. It will demonstrate a distinct Canadian initiative to build capacity for preventive eHealth services for patients with CHF. ClinicalTrials.gov NCT01864369; http://clinicaltrials.gov/ct2/show/NCT01864369 (Archived by WebCite at http://www.webcitation.org/6Iiv6so7E).
A comparison of the CHF between tubes and annuli under PWR thermal-hydraulic conditions
DOE Office of Scientific and Technical Information (OSTI.GOV)
Herer, C.; Souyri, A.; Garnier, J.
1995-09-01
Critical Heat Flux (CHF) tests were carried out in three tubes with inside diameters of 8, 13, and 19.2 mm and in two annuli with an inner tube of 9.5 mm and an outer tube of 13 or 19.2 mm. All axial heat flux distributions in the test sections were uniform. The coolant fluid was Refrigerant 12 (Freon-12) under PWR thermal-hydraulic conditions (equivalent water conditions - Pressure: 7 to 20 MPa, Mass Velocity: 1000 to 6000 kg/m2/s, Local Quality: -75% to +45%). The effect of tube diameter is correlated for qualities under 15%. The change from the tube to themore » annulus configuration is correctly taken into account by the equivalent hydraulic diameter. Useful information is also provided concerning the effect of a cold wall in an annulus.« less
A study of nucleate boiling and critical heat flux with EHD enhancement
NASA Astrophysics Data System (ADS)
Hristov, Y.; Zhao, D.; Kenning, D. B. R.; Sefiane, K.; Karayiannis, T. G.
2009-05-01
The paper describes results from an experimental and theoretical study of the effect of an electric field on nucleate boiling and the critical heat flux (CHF) in pool boiling of R123 at atmospheric pressure on a horizontal wall with a smooth surface. Two designs of electrode (parallel rods and wire mesh) were used. The experimental data exhibit some differences from the data obtained by other researchers in similar experiments on a wall with a different surface finish and with a slightly different design of wire mesh electrode. The hydrodynamic model for EHD enhancement of CHF cannot reconcile the differences. A theoretical model has been developed for the growth of a single vapour bubble on a superheated wall in an electric field, leading to a numerical simulation based on the level-set method. The model includes matching of sub-models for the micro- and macro-regions, conduction in the wall, distortion of the electric field by the bubble, the temperature dependence of electrical properties and free-charge generation. In the present form of the model, some of these effects are realised in an approximate form. The capability to investigate dry-spot formation and wall temperature changes that might lead to CHF has been demonstrated.
Combining liquid inertia with pressure recovery from bubble expansion for enhanced flow boiling
NASA Astrophysics Data System (ADS)
Kalani, A.; Kandlikar, S. G.
2015-11-01
In this paper, we demonstrate using liquid inertia force in a taper gap microchannel geometry to provide a high level of heat dissipation capacity accompanied by a high heat transfer coefficient and low pressure drop during flow boiling. The high mass flux increases liquid inertia force and promotes vapor removal from the manifold, thereby increasing critical heat flux (CHF) and heat transfer coefficient. The tapered gap above the microchannels provides an increasing cross-sectional area in the flow direction. This gap allows bubbles to emerge from microchannels and expand within the gap along the flow direction. The bubble evaporation and expansion in tapered gap causes pressure recovery and reduces the total pressure drop. The pressure recovery increases with the increased evaporation rate at higher heat fluxes. Using a 6% taper and a moderately high inlet liquid flow Reynolds number of 1095, we have reached a CHF of 1.07 kW/cm2 with a heat transfer coefficient of 295 kW/m2 °C and a pressure drop of 30 kPa.
Experimental research and numerical simulation on cryogenic line chill-down process
NASA Astrophysics Data System (ADS)
Jin, Lingxue; Cho, Hyokjin; Lee, Cheonkyu; Jeong, Sangkwon
2018-01-01
The empirical heat transfer correlations are suggested for the fast cool down process of the cryogenic transfer line from room temperature to cryogenic temperature. The correlations include the heat transfer coefficient (HTC) correlations for single-phase gas convection and film boiling regimes, minimum heat flux (MHF) temperature, critical heat flux (CHF) temperature and CHF. The correlations are obtained from the experimental measurements. The experiments are conducted on a 12.7 mm outer diameter (OD), 1.25 mm wall thickness and 7 m long stainless steel horizontal pipe with liquid nitrogen (LN2). The effect of the lengthwise position is verified by measuring the temperature profiles in near the inlet and the outlet of the transfer line. The newly suggested heat transfer correlations are applied to the one-dimensional homogeneous transient model to simulate the cryogenic line chill-down process, and the chill-down time and the cryogen consumption are well predicted in the mass flux range from 26.0 kg/m2 s to 73.6 kg/m2 s through the correlations.
Heat Deposition and Heat Removal in the UCLA Continuous Current Tokamak
NASA Astrophysics Data System (ADS)
Brown, Michael Lee
1990-01-01
Energy transfer processes in a steady-state tokamak are examined both theoretically and experimentally in order to determine the patterns of plasma heat deposition to material surfaces and the methods of heat removal. Heat transfer experiments involving actively cooled limiters and heat flux probes were performed in the UCLA Continuous Current Tokamak (CCT). The simple exponential model of plasma power deposition was extended to describe the global heat deposition to the first wall of a steady-state tokamak. The heat flux distribution in CCT was determined from measurements of heat flow to 32 large-area water-cooled Faraday shield panels. Significant toroidal and poloidal asymmetries were observed, with the maximum heat fluxes tending to fall on the lower outside panels. Heat deposition to the water-cooled guard limiters of an ion Bernstein wave antenna in CCT was measured during steady-state operation. Very strong asymmetries were observed. The heat distribution varied greatly with magnetic field. Copper heat flux sensors incorporating internal thermocouples were developed to measure plasma power deposition to exterior probe surfaces and heat removal from water -cooled interior surfaces. The resulting inverse heat conduction problem was solved using the function specification method. Cooling by an impinging liquid jet was investigated. One end of a cylindrical copper heat flux sensor was heated by a DC electrical arc and the other end was cooled by a low velocity water jet at 1 atm. Critical heat flux (CHF) values for the 55-80 ^circC sub-cooled free jets were typically 2.5 times published values for saturated free jets. For constrained jets, CHF values were about 20% lower. Heat deposition and heat removal in thick (3/4 inch diameter) cylindrical metal probes (SS304 or copper) inserted into a steady-state tokamak plasma were measured for a broad range of heat loads. The probes were cooled internally by a constrained jet of either air or water. Steady -state heat removal rates of up to 400 W/cm^2 were attained at the water cooled surface, and conditions of CHF were experimentally identified. Heat transfer in a hemispherical limiter is discussed.
DiBona, G F; Jones, S Y; Sawin, L L
2000-09-01
Nonlinear dynamic analysis was used to examine the chaotic behavior of renal sympathetic nerve activity in conscious rats subjected to either complete baroreceptor denervation (sinoaortic and cardiac baroreceptor denervation) or induction of congestive heart failure (CHF). The peak interval sequence of synchronized renal sympathetic nerve discharge was extracted and used for analysis. In control rats, this yielded a system whose correlation dimension converged to a low value over the embedding dimension range of 10-15 and whose greatest Lyapunov exponent was positive. Complete baroreceptor denervation was associated with a decrease in the correlation dimension of the system (before 2.65 +/- 0.27, after 1.64 +/- 0.17; P < 0.01) and a reduction in chaotic behavior (greatest Lyapunov exponent: 0.201 +/- 0.008 bits/data point before, 0.177 +/- 0.004 bits/data point after, P < 0.02). CHF, a state characterized by impaired sinoaortic and cardiac baroreceptor regulation of renal sympathetic nerve activity, was associated with a similar decrease in the correlation dimension (control 3.41 +/- 0.23, CHF 2.62 +/- 0.26; P < 0.01) and a reduction in chaotic behavior (greatest Lyapunov exponent: 0.205 +/- 0.048 bits/data point control, 0.136 +/- 0.033 bits/data point CHF, P < 0.02). These results indicate that removal of sinoaortic and cardiac baroreceptor regulation of renal sympathetic nerve activity, occurring either physiologically or pathophysiologically, is associated with a decrease in the correlation dimensions of the system and a reduction in chaotic behavior.
CHF Enhancement by Vessel Coating for External Reactor Vessel Cooling
DOE Office of Scientific and Technical Information (OSTI.GOV)
Fan-Bill Cheung; Joy L. Rempe
2004-06-01
In-vessel retention (IVR) is a key severe accident management (SAM) strategy that has been adopted by some operating nuclear power plants and advanced light water reactors (ALWRs). One viable means for IVR is the method of external reactor vessel cooling (ERVC) by flooding of the reactor cavity during a severe accident. As part of a joint Korean – United States International Nuclear Energy Research Initiative (K-INERI), an experimental study has been conducted to investigate the viability of using an appropriate vessel coating to enhance the critical heat flux (CHF) limits during ERVC. Toward this end, transient quenching and steady-state boilingmore » experiments were performed in the SBLB (Subscale Boundary Layer Boiling) facility at Penn State using test vessels with micro-porous aluminum coatings. Local boiling curves and CHF limits were obtained in these experiments. When compared to the corresponding data without coatings, substantial enhancement in the local CHF limits for the case with surface coatings was observed. Results of the steady state boiling experiments showed that micro-porous aluminum coatings were very durable. Even after many cycles of steady state boiling, the vessel coatings remained rather intact, with no apparent changes in color or structure. Moreover, the heat transfer performance of the coatings was found to be highly desirable with an appreciable CHF enhancement in all locations on the vessel outer surface but with very little effect of aging.« less
CHF considerations for highly moderated 100% MOX fuels PWRs
DOE Office of Scientific and Technical Information (OSTI.GOV)
Saphier, D.; Raymond, P.
1995-09-01
A feasibility study on using 100% MOX fuel in a PWR with increased moderating ratio, RMA, was initiated. In the proposed design all the parameters were chosen identical to the French 1450MW PWR, except the fuel pin diameter which was reduced to achieve higher moderating ratios, V{sub M}/V{sub F}, where V{sub M} and V{sub F} are the moderator and fuel volume respectively. Moderating ratios from 2 to 4 were considered. In the present study the thermal-hydraulic feasibility of using fuel assemblies with smaller diameter fuel pins was investigated. The major design constrain in this study was the critical heat fluxmore » (CHF). In order to maintain the fuel pin integrity under nominal operating and transient conditions, the minimum DNBR, (Departure from Nucleate Boiling Ratio given by CHF/q{close_quotes}{sub local}, where q{close_quotes}{sub local} is the local heat flux), has to be above a given value. The limitations of the existing CHF correlations for the present study are outlined. Two designs based on the conventional 17x17 fuel assembly and on the advanced 19x19 assembly meeting the MDNBR criteria and satisfying the control margin requirements, are proposed.« less
Li, Calvin H.; Rioux, Russell P.
2016-01-01
Spherical Cu nanocavity surfaces are synthesized to examine the individual role of contact angles in connecting lateral Rayleigh-Taylor wavelength to vertical Kevin-Helmholtz wavelength on hydrodynamic instability for the onset of pool boiling Critical Heat Flux (CHF). Solid and porous Cu pillar surfaces are sintered to investigate the individual role of pillar structure pitch at millimeter scale, named as module wavelength, on hydrodynamic instability at CHF. Last, spherical Cu nanocavities are coated on the porous Cu pillars to create a multiscale Cu structure, which is studied to examine the collective role and relative significance of contact angles and module wavelength on hydrodynamic instability at CHF, and the results indicate that module wavelength plays the dominant role on hydrodynamic instability at CHF when the height of surface structures is equal or above ¼ Kelvin-Helmholtz wavelength. Pool boiling Heat Transfer Coefficient (HTC) enhancements on spherical Cu nanocavity surfaces, solid and porous Cu pillar surfaces, and the integrated multiscale structure have been investigated, too. The experimental results reveal that the nanostructures and porous pillar structures can be combined together to achieve even higher enhancement of HTC than that of individual structures. PMID:27841322
Boiling Visualization and Critical Heat Flux Phenomena In Narrow Rectangular Gap
DOE Office of Scientific and Technical Information (OSTI.GOV)
J. J. Kim; Y. H. Kim; S. J. Kim
2004-12-01
An experimental study was performed to investifate the pool boling critical hear flux (CHF) on one-dimensional inclined rectangular channels with narrow gaps by changing the orientation of a copper test heater assembly. In a pool of saturated water at atmospheric pressure, the test parameters include the gap sizes of 1,2,5, and 10 mm, andthe surface orientation angles from the downward facing position (180 degrees) to the vertical position (90 degress) respectively.
Multi-Nozzle Spray Cooling in a Closed Loop (POSTPRINT)
2011-03-01
characteristics and critical heat flux (CHF) at cooling surfaces (Sehmbey et al., 1992, Mudawar and Estes, 1996, Rini et al., 2002, Lin and Ponnappan, 2003...surface characteristics in evaporative spray cooling, Journal of Thermophysics and heat Transfer, 1992, Vol. 6, pp. 505-512. 3. Mudawar , I., and
Measurement of Key Pool BOiling Parameters in nanofluids for Nuclerar Applications
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bang, In C; Buongiorno, Jdacopo; Hu, Lin-wen
Nanofluids, colloidal dispersions of nanoparticles in a base fluid such as water, can afford very significant Critical Heat Flux (CHF) enhancement. Such engineered fluids potentially could be employed in reactors as advanced coolants in safety systems with significant safety and economic advantages. However, a satisfactory explanation of the CHF enhancement mechanism in nanofluids is lacking. To close this gap, we have identified the important boiling parameters to be measured. These are the properties (e.g., density, viscosity, thermal conductivity, specific heat, vaporization enthalpy, surface tension), hydrodynamic parameters (i.e., bubble size, bubble velocity, departure frequency, hot/dry spot dynamics) and surface conditions (i.e.,more » contact angle, nucleation site density). We have also deployed a pool boiling facility in which many such parameters can be measured. The facility is equipped with a thin indium-tin-oxide heater deposited over a sapphire substrate. An infra-red high-speed camera and an optical probe are used to measure the temperature distribution on the heater and the hydrodynamics above the heater, respectively. The first data generated with this facility already provide some clue on the CHF enhancement mechanism in nanofluids. Specifically, the progression to burnout in a pure fluid (ethanol in this case) is characterized by a smoothly-shaped and steadily-expanding hot spot. By contrast, in the ethanol-based nanofluid the hot spot pulsates and the progression to burnout lasts longer, although the nanofluid CHF is higher than the pure fluid CHF. The presence of a nanoparticle deposition layer on the heater surface seems to enhance wettability and aid hot spot dissipation, thus delaying burnout.« less
Impact of Cubic Pin Finned Surface Structure Geometry upon Spray Cooling Heat Transfer
NASA Technical Reports Server (NTRS)
Silk, Eric A.; Kim, Jungho; Kiger, Ken
2005-01-01
Experiments were conducted to study the effects of enhanced surface structures on heat flux using spray cooling. The surface enhancements consisted of cubic pin fins machined on the top surface of copper heater blocks. The structure height, pitch, and width were parametrically vaned. Each copper block had a projected cross-sectional area of 2.0 sq cm. Measurements were also obtained on a heater block with a flat surface for baseline comparison purposes. A 2 x 2 nozzle array was used with PF-5060 as the working fluid. Thermal performance data were obtained under nominally degassed (chamber pressure of 41.4 kPa) and gassy conditions (chamber with N2 gas at 100.7 kPa) with a bulk fluid temperature of 20.5 C. Results for both the degassed and gassy cases show that structure width and separation distance have a dominant effect upon the heat transfer for the size ranges used. Cubic pin fin height had little impact upon heat flux. The maximum critical heat flux (CHF) attained for any of the surfaces was 121 W/sq cm, giving an enhancement of 51% relative to the flat surface case under nominally degassed conditions. The gassy case had a maximum CHF of 149 W/sq cm, giving an enhancement of 38% relative to the flat surface case.
Nucleate boiling performance on nano/microstructures with different wetting surfaces
2012-01-01
A study of nucleate boiling phenomena on nano/microstructures is a very basic and useful study with a view to the potential application of modified surfaces as heating surfaces in a number of fields. We present a detailed study of boiling experiments on fabricated nano/microstructured surfaces used as heating surfaces under atmospheric conditions, employing identical nanostructures with two different wettabilities (silicon-oxidized and Teflon-coated). Consequently, enhancements of both boiling heat transfer (BHT) and critical heat flux (CHF) are demonstrated in the nano/microstructures, independent of their wettability. However, the increment of BHT and CHF on each of the different wetting surfaces depended on the wetting characteristics of heating surfaces. The effect of water penetration in the surface structures by capillary phenomena is suggested as a plausible mechanism for the enhanced CHF on the nano/microstructures regardless of the wettability of the surfaces in atmospheric condition. This is supported by comparing bubble shapes generated in actual boiling experiments and dynamic contact angles under atmospheric conditions on Teflon-coated nano/microstructured surfaces. PMID:22559173
DOE Office of Scientific and Technical Information (OSTI.GOV)
Metzler, Dominik; Li, Chen; Engelmann, Sebastian
The need for atomic layer etching (ALE) is steadily increasing as smaller critical dimensions and pitches are required in device patterning. A flux-control based cyclic Ar/C 4F 8 ALE based on steady-state Ar plasma in conjunction with periodic, precise C 4F 8 injection and synchronized plasma-based low energy Ar + ion bombardment has been established for SiO 2. 1 In this work, the cyclic process is further characterized and extended to ALE of silicon under similar process conditions. The use of CHF 3 as a precursor is examined and compared to C 4F 8. CHF 3 is shown to enablemore » selective SiO 2/Si etching using a fluorocarbon (FC) film build up. Other critical process parameters investigated are the FC film thickness deposited per cycle, the ion energy, and the etch step length. Etching behavior and mechanisms are studied using in situ real time ellipsometry and X-ray photoelectron spectroscopy. Silicon ALE shows less self-limitation than silicon oxide due to higher physical sputtering rates for the maximum ion energies used in this work, ranged from 20 to 30 eV. The surface chemistry is found to contain fluorinated silicon oxide during the etching of silicon. As a result, plasma parameters during ALE are studied using a Langmuir probe and establish the impact of precursor addition on plasma properties.« less
NASA Astrophysics Data System (ADS)
Kshirsagar, Jagdeep M.; Shrivastava, Ramakant
2018-06-01
In Present study, the critical heat flux (CHF) and boiling heat transfer coefficient of alumina nanoparticles with the base fluid as deionised water is measured. The selected concentrations of nanofluids for the experimentation are from 0.3, 0.6, 0.9, 1.2 and 1.5 wt%. The main objective to select higher concentration is that to study the surface morphology of heater surface at higher concentrations and its effect on critical heat flux and heat transfer coefficient. It is observed that the critical heat flux enhancement rate decreases as concentration increases and surface roughness of heater surface decreases after 1.2 wt% concentration of nanofluids.
Boiling on Microconfigured Composite Surfaces Enhanced
NASA Technical Reports Server (NTRS)
Chao, David F.
2000-01-01
Boiling heat transfer is one of the key technologies for the two-phase active thermal-control system used on space platforms, as well as for the dynamic power systems aboard the International Space Station. Because it is an effective heat transfer mode, boiling is integral to many space applications, such as heat exchangers and other cooling devices. Nucleate boiling near the critical heat flux (CHF) can transport very large thermal loads with a much smaller device and much lower pumping power than for single-phase heat exchangers. However, boiling performance sharply deteriorates in a reduced-gravity environment, and operation in the CHF regime is somewhat perilous because of the risk of burnout to the device surface. New materials called microconfigured metal-graphite composites can enhance boiling. The photomicrograph shows the microconfiguration (x3000) of the copper-graphite (Cu-Gr) surface as viewed by scanning electronic microscope. The graphite fiber tips appear as plateaus with rugged surfaces embedded in the copper matrix. It has been experimentally demonstrated that this type of material manifests excellent boiling heat transfer performance characteristics and an increased CHF. Nonisothermal surfaces were less sensitive to variations of wall superheat in the CHF regime. Because of the great difference in conductivity between the copper base and the graphite fiber, the composite surfaces have a nonisothermal surface characteristic and, therefore, will have a much larger "safe" operating region in the CHF regime. In addition, the thermocapillary forces induced by the temperature differences between the fiber tips and the metal matrix play an important role in bubble detachment, and may not be adversely affected in a reduced-gravity environment. All these factors indicate that microconfigured composites may improve the reliability and economy (dominant factors in all space applications) of various thermal components found on spacecraft during future missions.
Enhancement of Boiling Heat Transfer in Di-Electric Fluids
1991-09-01
working fluid of R-I13. Maddox and Mudawar [Ref. 8] studied the effect of subcooling and surface aug- mentation on values of Critical Heat Flux (CHF). They...Enhanced Surfaces to Dielectric Fluids," A SME Journal of Heat Transfer, v.104, pp.292-299, May 1982. 8. Maddox D.E., and Mudawar ,I., "Single and Two
The role of heater thermal response in reactor thermal limits during oscillartory two-phase flows
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ruggles, A.E.; Brown, N.W.; Vasil`ev, A.D.
1995-09-01
Analytical and numerical investigations of critical heat flux (CHF) and reactor thermal limits are conducted for oscillatory two-phase flows often associated with natural circulation conditions. It is shown that the CHF and associated thermal limits depend on the amplitude of the flow oscillations, the period of the flow oscillations, and the thermal properties and dimensions of the heater. The value of the thermal limit can be much lower in unsteady flow situations than would be expected using time average flow conditions. It is also shown that the properties of the heater strongly influence the thermal limit value in unsteady flowmore » situations, which is very important to the design of experiments to evaluate thermal limits for reactor fuel systems.« less
FILM-30: A Heat Transfer Properties Code for Water Coolant
DOE Office of Scientific and Technical Information (OSTI.GOV)
MARSHALL, THERON D.
2001-02-01
A FORTRAN computer code has been written to calculate the heat transfer properties at the wetted perimeter of a coolant channel when provided the bulk water conditions. This computer code is titled FILM-30 and the code calculates its heat transfer properties by using the following correlations: (1) Sieder-Tate: forced convection, (2) Bergles-Rohsenow: onset to nucleate boiling, (3) Bergles-Rohsenow: partially developed nucleate boiling, (4) Araki: fully developed nucleate boiling, (5) Tong-75: critical heat flux (CHF), and (6) Marshall-98: transition boiling. FILM-30 produces output files that provide the heat flux and heat transfer coefficient at the wetted perimeter as a function ofmore » temperature. To validate FILM-30, the calculated heat transfer properties were used in finite element analyses to predict internal temperatures for a water-cooled copper mockup under one-sided heating from a rastered electron beam. These predicted temperatures were compared with the measured temperatures from the author's 1994 and 1998 heat transfer experiments. There was excellent agreement between the predicted and experimentally measured temperatures, which confirmed the accuracy of FILM-30 within the experimental range of the tests. FILM-30 can accurately predict the CHF and transition boiling regimes, which is an important advantage over current heat transfer codes. Consequently, FILM-30 is ideal for predicting heat transfer properties for applications that feature high heat fluxes produced by one-sided heating.« less
Mahajan, Ruhi; Viangteeravat, Teeradache; Akbilgic, Oguz
2017-12-01
A timely diagnosis of congestive heart failure (CHF) is crucial to evade a life-threatening event. This paper presents a novel probabilistic symbol pattern recognition (PSPR) approach to detect CHF in subjects from their cardiac interbeat (R-R) intervals. PSPR discretizes each continuous R-R interval time series by mapping them onto an eight-symbol alphabet and then models the pattern transition behavior in the symbolic representation of the series. The PSPR-based analysis of the discretized series from 107 subjects (69 normal and 38 CHF subjects) yielded discernible features to distinguish normal subjects and subjects with CHF. In addition to PSPR features, we also extracted features using the time-domain heart rate variability measures such as average and standard deviation of R-R intervals. An ensemble of bagged decision trees was used to classify two groups resulting in a five-fold cross-validation accuracy, specificity, and sensitivity of 98.1%, 100%, and 94.7%, respectively. However, a 20% holdout validation yielded an accuracy, specificity, and sensitivity of 99.5%, 100%, and 98.57%, respectively. Results from this study suggest that features obtained with the combination of PSPR and long-term heart rate variability measures can be used in developing automated CHF diagnosis tools. Copyright © 2017 Elsevier B.V. All rights reserved.
Flow Boiling and Condensation Experiment (FBCE) for the International Space Station
NASA Technical Reports Server (NTRS)
Mudawar, Issam; O'Neill, Lucas; Hasan, Mohammad; Nahra, Henry; Hall, Nancy; Balasubramaniam, R.; Mackey, Jeffrey
2016-01-01
An effective means to reducing the size and weight of future space vehicles is to replace present mostly single-phase thermal management systems with two-phase counterparts. By capitalizing upon both latent and sensible heat of the coolant rather than sensible heat alone, two-phase thermal management systems can yield orders of magnitude enhancement in flow boiling and condensation heat transfer coefficients. Because the understanding of the influence of microgravity on two-phase flow and heat transfer is quite limited, there is an urgent need for a new experimental microgravity facility to enable investigators to perform long-duration flow boiling and condensation experiments in pursuit of reliable databases, correlations and models. This presentation will discuss recent progress in the development of the Flow Boiling and Condensation Experiment (FBCE) for the International Space Station (ISS) in collaboration between Purdue University and NASA Glenn Research Center. Emphasis will be placed on the design of the flow boiling module and on new flow boiling data that were measured in parabolic flight, along with extensive flow visualization of interfacial features at heat fluxes up to critical heat flux (CHF). Also discussed a theoretical model that will be shown to predict CHF with high accuracy.
Exercise training in chronic heart failure: improving skeletal muscle O2 transport and utilization
Hirai, Daniel M.; Musch, Timothy I.
2015-01-01
Chronic heart failure (CHF) impairs critical structural and functional components of the O2 transport pathway resulting in exercise intolerance and, consequently, reduced quality of life. In contrast, exercise training is capable of combating many of the CHF-induced impairments and enhancing the matching between skeletal muscle O2 delivery and utilization (Q̇mO2 and V̇mO2, respectively). The Q̇mO2/V̇mO2 ratio determines the microvascular O2 partial pressure (PmvO2), which represents the ultimate force driving blood-myocyte O2 flux (see Fig. 1). Improvements in perfusive and diffusive O2 conductances are essential to support faster rates of oxidative phosphorylation (reflected as faster V̇mO2 kinetics during transitions in metabolic demand) and reduce the reliance on anaerobic glycolysis and utilization of finite energy sources (thus lowering the magnitude of the O2 deficit) in trained CHF muscle. These adaptations contribute to attenuated muscle metabolic perturbations (e.g., changes in [PCr], [Cr], [ADP], and pH) and improved physical capacity (i.e., elevated critical power and maximal V̇mO2). Preservation of such plasticity in response to exercise training is crucial considering the dominant role of skeletal muscle dysfunction in the pathophysiology and increased morbidity/mortality of the CHF patient. This brief review focuses on the mechanistic bases for improved Q̇mO2/V̇mO2 matching (and enhanced PmvO2) with exercise training in CHF with both preserved and reduced ejection fraction (HFpEF and HFrEF, respectively). Specifically, O2 convection within the skeletal muscle microcirculation, O2 diffusion from the red blood cell to the mitochondria, and muscle metabolic control are particularly susceptive to exercise training adaptations in CHF. Alternatives to traditional whole body endurance exercise training programs such as small muscle mass and inspiratory muscle training, pharmacological treatment (e.g., sildenafil and pentoxifylline), and dietary nitrate supplementation are also presented in light of their therapeutic potential. Adaptations within the skeletal muscle O2 transport and utilization system underlie improvements in physical capacity and quality of life in CHF and thus take center stage in the therapeutic management of these patients. PMID:26320036
An adsorption model for the superheat at the critical heat flux
DOE Office of Scientific and Technical Information (OSTI.GOV)
Reyes, R.; Wayner, P.C. Jr.
1995-08-01
The evaluation of the superheat at the critical heat flux (CHF) is a problem of considerable importance to the field of change-of-phase heat transfer. As demonstrated in the recent reviews by Katto and Bergles and in a descriptive paper by Unal et al., there has been extensive prior research on the CHF. In these studies, the following descriptive modeling terms affirm the complex transport processes occurring at CHF: macrolayer, microlayer, apparent contact angle, real contact angle, spreading, dry patch, instability, vapor mushrooms, and interfacial conditions. In order to simplify the analyses of these phenomena, we focus herein on a moremore » tractable model, which emphasizes a characteristic thickness in the contact line region at the vapor-liquid-solid junction, which would be present in the thinnest portion of an evaporating microlayer. A schematic drawing of this region is presented in Fig. 1 for a nonisothermal completely wetting system. This is the region where the substrate dries out in the hot spot hypothesis. The solid substrate is modeled as having an adsorbed ultrathin layer of liquid with a thickness {delta}, which is a function of the superheat and the interfacial force field. The characteristic thickness, {delta}{sub 0}, can (but does not have to) be of the order of a monolayer or less. Therefore, in the region x < 0, the film can be discontinuous and fill in {open_quotes}depressions{close_quotes} on a {open_quotes}rough{close_quotes} surface. Herein, a model of the physically indistinct contact line region, which varies spatially and fluctuates at the molecular level, is used to develop a predictive equation for the average value of the superheat that can be evaluated macroscopically. 9 refs., 2 figs., 1 tab.« less
Study of Critical Heat Flux and Two-Phase Pressure Drop Under Reduced Gravity
NASA Technical Reports Server (NTRS)
Abdollahian, Davood; Quintal, Joseph; Barez, Fred; Zahm, Jennifer; Lohr, Victor
1996-01-01
The design of the two-phase flow systems which are anticipated to be utilized in future spacecraft thermal management systems requires a knowledge of two-phase flow and heat transfer phenomena in reduced gravities. This program was funded by NASA headquarters in response to NRA-91-OSSA-17 and was managed by Lewis Research Center. The main objective of this program was to design and construct a two-phase test loop, and perform a series of normal gravity and aircraft trajectory experiments to study the effect of gravity on the Critical Heat Flux (CHF) and onset of instability. The test loop was packaged on two aircraft racks and was also instrumented to generate data for two-phase pressure drop. The normal gravity tests were performed with vertical up and downflow configurations to bound the effect of gravity on the test parameters. One set of aircraft trajectory tests was performed aboard the NASA DC-9 aircraft. These tests were mainly intended to evaluate the test loop and its operational performance under actual reduced gravity conditions, and to produce preliminary data for the test parameters. The test results were used to demonstrate the applicability of the normal gravity models for prediction of the two-phase friction pressure drop. It was shown that the two-phase friction multipliers for vertical upflow and reduced gravity conditions can be successfully predicted by the appropriate normal gravity models. Limited critical heat flux data showed that the measured CHF under reduced gravities are of the same order of magnitude as the test results with vertical upflow configuration. A simplified correlation was only successful in predicting the measured CHF for low flow rates. Instability tests with vertical upflow showed that flow becomes unstable and critical heat flux occurs at smaller powers when a parallel flow path exists. However, downflow tests and a single reduced gravity instability experiment indicated that the system actually became more stable with a parallel single-phase flow path. Several design modifications have been identified which will improve the system performance for generating reduced gravity data. The modified test loop can provide two-phase flow data for a range of operating conditions and can serve as a test bed for component evaluation.
NASA Astrophysics Data System (ADS)
Ueno, Ichiro; Ando, Jun; Horiuchi, Kazuna; Saiki, Takahito; Kaneko, Toshihiro
2016-11-01
Microbubble emission boiling (MEB) produces a higher heat flux than critical heat flux (CHF) and therefore has been investigated in terms of its heat transfer characteristics as well as the conditions under which MEB occurs. Its physical mechanism, however, is not yet clearly understood. We carried out a series of experiments to examine boiling on horizontal circular heated surfaces of 5 mm and of 10 mm in diameter, in a subcooled pool, paying close attention to the transition process to MEB. High-speed observation results show that, in the MEB regime, the growth, condensation, and collapse of the vapor bubbles occur within a very short time. In addition, a number of fine bubbles are emitted from the collapse of the vapor bubbles. By tracking these tiny bubbles, we clearly visualize that the collapse of the vapor bubbles drives the liquid near the bubbles towards the heated surface, such that the convection field around the vapor bubbles under MEB significantly differs from that under nucleate boiling. Moreover, the axial temperature gradient in a heated block (quasi-heat flux) indicates a clear difference between nucleate boiling and MEB. A combination of quasi-heat flux and the measurement of the behavior of the vapor bubbles allows us to discuss the transition to MEB. This work was financially supported by the 45th Research Grant in Natural Sciences from The Mitsubishi Foundation (2014 - 2015), and by Research Grant for Boiler and Pressurized Vessels from The Japan Boiler Association (2016).
DOE Office of Scientific and Technical Information (OSTI.GOV)
Metzler, Dominik; Oehrlein, Gottlieb S., E-mail: oehrlein@umd.edu; Li, Chen
The need for atomic layer etching (ALE) is steadily increasing as smaller critical dimensions and pitches are required in device patterning. A flux-control based cyclic Ar/C{sub 4}F{sub 8} ALE based on steady-state Ar plasma in conjunction with periodic, precise C{sub 4}F{sub 8} injection and synchronized plasma-based low energy Ar{sup +} ion bombardment has been established for SiO{sub 2} [Metzler et al., J. Vac. Sci. Technol. A 32, 020603 (2014)]. In this work, the cyclic process is further characterized and extended to ALE of silicon under similar process conditions. The use of CHF{sub 3} as a precursor is examined and comparedmore » to C{sub 4}F{sub 8}. CHF{sub 3} is shown to enable selective SiO{sub 2}/Si etching using a fluorocarbon (FC) film build up. Other critical process parameters investigated are the FC film thickness deposited per cycle, the ion energy, and the etch step length. Etching behavior and mechanisms are studied using in situ real time ellipsometry and x-ray photoelectron spectroscopy. Silicon ALE shows less self-limitation than silicon oxide due to higher physical sputtering rates for the maximum ion energies used in this work, ranged from 20 to 30 eV. The surface chemistry is found to contain fluorinated silicon oxide during the etching of silicon. Plasma parameters during ALE are studied using a Langmuir probe and establish the impact of precursor addition on plasma properties.« less
Gamma scintigraphic analysis of albumin flux in patients with acute respiratory distress syndrome
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sugerman, H.J.; Tatum, J.L.; Burke, T.S.
1984-06-01
Computerized gamma-scintigraphy provides a new method for the analysis of albumin flux in patients with pulmonary permeability edema. In this technique, 10 mCi of /sup 99/mTc -tagged human serum albumin is administered and lung:heart radioactivity ratios are determined. This ratio remains constant unless there is a leak of albumin, when a rising ratio with time, called the ''slope index'' (SI), is seen. Thirty-five scintigraphic studies were obtained in 28 patients by means of a portable computerized gamma-camera. Thirteen of these patients had clinical evidence of the acute respiratory distress syndrome (ARDS) and six had or were recovering from left ventricularmore » induced congestive heart failure (CHF). Five of the patients with CHF and pulmonary capillary wedge pressure (PCWP) below 30 mm Hg had normal scintigraphic studies. The patients with ARDS were found to have significantly higher SIs than patients who did not have, or had recovered from, ARDS. Positive SIs were present from 1 to 8 days following the apparent onset of ARDS in seven studies in five patients. Recovery of gas exchange was associated with a return to a normal SI in four patients. In conclusion, computerized gamma-scintigraphy was a sensitive, noninvasive tool for the detection of a pathologic increase in pulmonary protein flux. Positive scintigraphic findings were associated with significantly impaired gas exchange. The method documented that the leak of albumin in patients with ARDS may last for days but resolves with recovery.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Thomas, D.G.; Baucum, W.E.; Bohanan, R.E.
1977-10-01
The Thermal-Hydraulic Test Facility (THTF) has completed 20 powered rod blowdowns through October 13, 1977. Of these blowdowns, 5 were completed with all 49 rods powered, 2 were completed with 2 inactive rods, and 13 were completed with 4 inactive rods. Initial system pressure was 15.5 MPa, test section inlet temperature was 559 K, and break area was equivalent to a 200% break with the total area usually split between inlet and outlet in the ratio 0.40 : 0.60. Heater rod power was 80, 100, or 122 kW/rod, and the test section temperature was 607 K, 598 K, or 589more » K. Mean time to critical heat flux (CHF) varied from 0.7 to 1.4 sec with delayed CHF of 2.5 sec occurring in the upper half of the bundle in some tests.« less
Assessment of correlations and models for the prediction of CHF in water subcooled flow boiling
NASA Astrophysics Data System (ADS)
Celata, G. P.; Cumo, M.; Mariani, A.
1994-01-01
The present paper provides an analysis of available correlations and models for the prediction of Critical Heat Flux (CHF) in subcooled flow boiling in the range of interest of fusion reactors thermal-hydraulic conditions, i.e. high inlet liquid subcooling and velocity and small channel diameter and length. The aim of the study was to establish the limits of validity of present predictive tools (most of them were proposed with reference to light water reactors (LWR) thermal-hydraulic studies) in the above conditions. The reference dataset represents almost all available data (1865 data points) covering wide ranges of operating conditions in the frame of present interest (0.1 less than p less than 8.4 MPa; 0.3 less than D less than 25.4 mm; 0.1 less than L less than 0.61 m; 2 less than G less than 90.0 Mg/sq m/s; 90 less than delta T(sub sub,in) less than 230 K). Among the tens of predictive tools available in literature four correlations (Levy, Westinghouse, modified-Tong and Tong-75) and three models (Weisman and Ileslamlou, Lee and Mudawar and Katto) were selected. The modified-Tong correlation and the Katto model seem to be reliable predictive tools for the calculation of the CHF in subcooled flow boiling.
Infrared thermometry study of nanofluid pool boiling phenomena
2011-01-01
Infrared thermometry was used to obtain first-of-a-kind, time- and space-resolved data for pool boiling phenomena in water-based nanofluids with diamond and silica nanoparticles at low concentration (<0.1 vol.%). In addition to macroscopic parameters like the average heat transfer coefficient and critical heat flux [CHF] value, more fundamental parameters such as the bubble departure diameter and frequency, growth and wait times, and nucleation site density [NSD] were directly measured for a thin, resistively heated, indium-tin-oxide surface deposited onto a sapphire substrate. Consistent with other nanofluid studies, the nanoparticles caused deterioration in the nucleate boiling heat transfer (by as much as 50%) and an increase in the CHF (by as much as 100%). The bubble departure frequency and NSD were found to be lower in nanofluids compared with water for the same wall superheat. Furthermore, it was found that a porous layer of nanoparticles built up on the heater surface during nucleate boiling, which improved surface wettability compared with the water-boiled surfaces. Using the prevalent nucleate boiling models, it was possible to correlate this improved surface wettability to the experimentally observed reductions in the bubble departure frequency, NSD, and ultimately to the deterioration in the nucleate boiling heat transfer and the CHF enhancement. PMID:21711754
Clark, Robyn A; Driscoll, Andrea; Nottage, Justin; McLennan, Skye; Coombe, David M; Bamford, Errol J; Wilkinson, David; Stewart, Simon
2007-02-19
To compare the location and accessibility of current Australian chronic heart failure (CHF) management programs and general practice services with the probable distribution of the population with CHF. Data on the prevalence and distribution of the CHF population throughout Australia, and the locations of CHF management programs and general practice services from 1 January 2004 to 31 December 2005 were analysed using geographic information systems (GIS) technology. Distance of populations with CHF to CHF management programs and general practice services. The highest prevalence of CHF (20.3-79.8 per 1000 population) occurred in areas with high concentrations of people over 65 years of age and in areas with higher proportions of Indigenous people. Five thousand CHF patients (8%) discharged from hospital in 2004-2005 were managed in one of the 62 identified CHF management programs. There were no CHF management programs in the Northern Territory or Tasmania. Only four CHF management programs were located outside major cities, with a total case load of 80 patients (0.7%). The mean distance from any Australian population centre to the nearest CHF management program was 332 km (median, 163 km; range, 0.15-3246 km). In rural areas, where the burden of CHF management falls upon general practitioners, the mean distance to general practice services was 37 km (median, 20 km; range, 0-656 km). There is an inequity in the provision of CHF management programs to rural Australians.
Ferguson, Scott K.; Holdsworth, Clark T.; Colburn, Trenton D.; Wright, Jennifer L.; Craig, Jesse C.; Fees, Alex; Jones, Andrew M.; Allen, Jason D.; Musch, Timothy I.
2016-01-01
Chronic heart failure (CHF) results in central and peripheral derangements that ultimately reduce skeletal muscle O2 delivery and impair exercise tolerance. Dietary nitrate (NO3−) supplementation improves skeletal muscle vascular function and tolerance to exercise. We tested the hypothesis that NO3− supplementation would elevate exercising skeletal muscle blood flow (BF) and vascular conductance (VC) in CHF rats. Myocardial infarction (MI) was induced (coronary artery ligation) in young adult male rats. After 21 days of recovery, rats randomly received 5 days of NO3−-rich beetroot juice (CHF + BR, n = 10) or a placebo (CHF, n = 10). Mean arterial pressure (carotid artery catheter) and skeletal muscle BF (radiolabeled microspheres) were measured during treadmill exercise (20 m/min, 5% grade). CHF-induced dysfunction, as determined by myocardial infarction size (29 ± 3% and 33 ± 4% in CHF and CHF + BR, respectively) and left ventricular end-diastolic pressure (18 ± 2 and 18 ± 2 mmHg in CHF and CHF + BR, respectively), and exercising mean arterial pressure (131 ± 3 and 128 ± 4 mmHg in CHF and CHF + BR, respectively) were not different (P > 0.05) between groups. Total exercising hindlimb skeletal muscle BF (95 ± 5 and 116 ± 9 ml·min−1·100 g−1 in CHF and CHF + BR, respectively) and VC (0.75 ± 0.05 and 0.90 ± 0.05 ml·min−1·100 g−1·mmHg−1 in CHF and CHF + BR, respectively) were 22% and 20% greater in BR-supplemented rats, respectively (P < 0.05). During exercise, BF in 9 and VC in 10 hindlimb muscles and muscle portions were significantly greater in the CHF + BR group. These results provide strong evidence that dietary NO3− supplementation improves skeletal muscle vascular function during exercise in rats with CHF and, thus, support the use of BR as a novel therapeutic modality for the treatment of CHF. PMID:27445296
Ferguson, Scott K; Holdsworth, Clark T; Colburn, Trenton D; Wright, Jennifer L; Craig, Jesse C; Fees, Alex; Jones, Andrew M; Allen, Jason D; Musch, Timothy I; Poole, David C
2016-09-01
Chronic heart failure (CHF) results in central and peripheral derangements that ultimately reduce skeletal muscle O2 delivery and impair exercise tolerance. Dietary nitrate (NO3 (-)) supplementation improves skeletal muscle vascular function and tolerance to exercise. We tested the hypothesis that NO3 (-) supplementation would elevate exercising skeletal muscle blood flow (BF) and vascular conductance (VC) in CHF rats. Myocardial infarction (MI) was induced (coronary artery ligation) in young adult male rats. After 21 days of recovery, rats randomly received 5 days of NO3 (-)-rich beetroot juice (CHF + BR, n = 10) or a placebo (CHF, n = 10). Mean arterial pressure (carotid artery catheter) and skeletal muscle BF (radiolabeled microspheres) were measured during treadmill exercise (20 m/min, 5% grade). CHF-induced dysfunction, as determined by myocardial infarction size (29 ± 3% and 33 ± 4% in CHF and CHF + BR, respectively) and left ventricular end-diastolic pressure (18 ± 2 and 18 ± 2 mmHg in CHF and CHF + BR, respectively), and exercising mean arterial pressure (131 ± 3 and 128 ± 4 mmHg in CHF and CHF + BR, respectively) were not different (P > 0.05) between groups. Total exercising hindlimb skeletal muscle BF (95 ± 5 and 116 ± 9 ml·min(-1)·100 g(-1) in CHF and CHF + BR, respectively) and VC (0.75 ± 0.05 and 0.90 ± 0.05 ml·min(-1)·100 g(-1)·mmHg(-1) in CHF and CHF + BR, respectively) were 22% and 20% greater in BR-supplemented rats, respectively (P < 0.05). During exercise, BF in 9 and VC in 10 hindlimb muscles and muscle portions were significantly greater in the CHF + BR group. These results provide strong evidence that dietary NO3 (-) supplementation improves skeletal muscle vascular function during exercise in rats with CHF and, thus, support the use of BR as a novel therapeutic modality for the treatment of CHF. Copyright © 2016 the American Physiological Society.
Exercise training attenuates chemoreflex-mediated reductions of renal blood flow in heart failure
Pügge, Carolin; Mediratta, Jai; Schiller, Alicia M.; Del Rio, Rodrigo; Zucker, Irving H.; Schultz, Harold D.
2015-01-01
In chronic heart failure (CHF), carotid body chemoreceptor (CBC) activity is increased and contributes to increased tonic and hypoxia-evoked elevation in renal sympathetic nerve activity (RSNA). Elevated RSNA and reduced renal perfusion may contribute to development of the cardio-renal syndrome in CHF. Exercise training (EXT) has been shown to abrogate CBC-mediated increases in RSNA in experimental heart failure; however, the effect of EXT on CBC control of renal blood flow (RBF) is undetermined. We hypothesized that CBCs contribute to tonic reductions in RBF in CHF, that stimulation of the CBC with hypoxia would result in exaggerated reductions in RBF, and that these responses would be attenuated with EXT. RBF was measured in CHF-sedentary (SED), CHF-EXT, CHF-carotid body denervation (CBD), and CHF-renal denervation (RDNX) groups. We measured RBF at rest and in response to hypoxia (FiO2 10%). All animals exhibited similar reductions in ejection fraction and fractional shortening as well as increases in ventricular systolic and diastolic volumes. Resting RBF was lower in CHF-SED (29 ± 2 ml/min) than in CHF-EXT animals (46 ± 2 ml/min, P < 0.05) or in CHF-CBD animals (42 ± 6 ml/min, P < 0.05). In CHF-SED, RBF decreased during hypoxia, and this was prevented in CHF-EXT animals. Both CBD and RDNX abolished the RBF response to hypoxia in CHF. Mean arterial pressure increased in response to hypoxia in CHF-SED, but was prevented by EXT, CBD, and RDNX. EXT is effective in attenuating chemoreflex-mediated tonic and hypoxia-evoked reductions in RBF in CHF. PMID:26001414
Exercise training attenuates chemoreflex-mediated reductions of renal blood flow in heart failure.
Marcus, Noah J; Pügge, Carolin; Mediratta, Jai; Schiller, Alicia M; Del Rio, Rodrigo; Zucker, Irving H; Schultz, Harold D
2015-07-15
In chronic heart failure (CHF), carotid body chemoreceptor (CBC) activity is increased and contributes to increased tonic and hypoxia-evoked elevation in renal sympathetic nerve activity (RSNA). Elevated RSNA and reduced renal perfusion may contribute to development of the cardio-renal syndrome in CHF. Exercise training (EXT) has been shown to abrogate CBC-mediated increases in RSNA in experimental heart failure; however, the effect of EXT on CBC control of renal blood flow (RBF) is undetermined. We hypothesized that CBCs contribute to tonic reductions in RBF in CHF, that stimulation of the CBC with hypoxia would result in exaggerated reductions in RBF, and that these responses would be attenuated with EXT. RBF was measured in CHF-sedentary (SED), CHF-EXT, CHF-carotid body denervation (CBD), and CHF-renal denervation (RDNX) groups. We measured RBF at rest and in response to hypoxia (FiO2 10%). All animals exhibited similar reductions in ejection fraction and fractional shortening as well as increases in ventricular systolic and diastolic volumes. Resting RBF was lower in CHF-SED (29 ± 2 ml/min) than in CHF-EXT animals (46 ± 2 ml/min, P < 0.05) or in CHF-CBD animals (42 ± 6 ml/min, P < 0.05). In CHF-SED, RBF decreased during hypoxia, and this was prevented in CHF-EXT animals. Both CBD and RDNX abolished the RBF response to hypoxia in CHF. Mean arterial pressure increased in response to hypoxia in CHF-SED, but was prevented by EXT, CBD, and RDNX. EXT is effective in attenuating chemoreflex-mediated tonic and hypoxia-evoked reductions in RBF in CHF. Copyright © 2015 the American Physiological Society.
Nano-inspired fluidic interactivity for boiling heat transfer: impact and criteria
Kim, Beom Seok; Choi, Geehong; Shin, Sangwoo; Gemming, Thomas; Cho, Hyung Hee
2016-01-01
The enhancement of boiling heat transfer, the most powerful energy-transferring technology, will lead to milestones in the development of high-efficiency, next-generation energy systems. Perceiving nano-inspired interface functionalities from their rough morphologies, we demonstrate interface-induced liquid refreshing is essential to improve heat transfer by intrinsically avoiding Leidenfrost phenomenon. High liquid accessibility of hemi-wicking and catalytic nucleation, triggered by the morphological and hydrodynamic peculiarities of nano-inspired interfaces, contribute to the critical heat flux (CHF) and the heat transfer coefficient (HTC). Our experiments show CHF is a function of universal hydrodynamic characteristics involving interfacial liquid accessibility and HTC is improved with a higher probability of smaller nuclei with less superheat. Considering the interface-induced and bulk liquid accessibility at boiling, we discuss functionalizing the interactivity between an interface and a counteracting fluid seeking to create a novel interface, a so-called smart interface, for a breakthrough in boiling and its pragmatic application in energy systems. PMID:27708341
Congestive heart failure in children with pneumonia and respiratory failure.
Nimdet, Kachaporn; Techakehakij, Win
2017-03-01
Congestive heart failure (CHF) is one of the most common cardiac complications of pneumonia in adulthood leading to increased risk of morbidity and mortality. Little is known, however, of CHF and pneumonia in children. The aim of this study was therefore to investigate the characteristics and factors associated with CHF in under-5 children with pneumonia and respiratory failure. A retrospective cohort was conducted in hospitalized patients aged 2-59 months with community-acquired pneumonia and respiratory failure from June 2011 to June 2014 at Suratthani Hospital, Thailand. The characteristics, therapeutic strategy, and clinical outcomes of CHF were reviewed. Baseline characteristics and basic laboratory investigations on admission were compared between the CHF and non-CHF groups. Of 135 patients, 14 (10%) had CHF. Compared with patients without CHF, the CHF group had prolonged intubation and hospital stay and high rates of associated complications such as ventilator-associated pneumonia, sepsis, shock, and 30 day mortality. CHF was significantly associated with certain characteristics, including male sex and bacterial pneumonia. Pneumonia with respiratory failure is associated with CHF even in healthy children without cardiac risks. The awareness and early recognition of CHF, particularly in male, and bacterial pneumonia, is important in order to provide immediate treatment to reduce complications. © 2016 Japan Pediatric Society.
Contribution of peripheral and central chemoreceptors to sympatho‐excitation in heart failure
Toledo, Camilo; Andrade, David C.; Lucero, Claudia; Schultz, Harold D.; Marcus, Noah; Retamal, Mauricio; Madrid, Carlos
2016-01-01
Abstract Chronic heart failure (CHF) is a major public health problem. Tonic hyper‐activation of sympathetic neural outflow is commonly observed in patients with CHF. Importantly, sympatho‐excitation in CHF exacerbates its progression and is strongly related to poor prognosis and high mortality risk. Increases in both peripheral and central chemoreflex drive are considered markers of the severity of CHF. The principal peripheral chemoreceptors are the carotid bodies (CBs) and alteration in their function has been described in CHF. Mainly, during CHF the CB chemosensitivity is enhanced leading to increases in ventilation and sympathetic outflow. In addition to peripheral control of breathing, central chemoreceptors (CCs) are considered a dominant mechanism in ventilatory regulation. Potentiation of the ventilatory and sympathetic drive in response to CC activation has been shown in patients with CHF as well as in animal models. Therefore, improving understanding of the contribution of the peripheral and central chemoreflexes to augmented sympathetic discharge in CHF could help in developing new therapeutic approaches intended to attenuate the progression of CHF. Accordingly, the main focus of this review is to discuss recent evidence that peripheral and central chemoreflex function are altered in CHF and that they contribute to autonomic imbalance and progression of CHF. PMID:27218485
Prevention of relapse in patients with congestive heart failure: the role of precipitating factors
Feenstra, J; Grobbee, D; Jonkman, F; Hoes, A; Stricker, B
1998-01-01
Relapse of congestive heart failure (CHF) frequently occurs and has serious consequences in terms of morbidity, mortality, and health care expenditure. Many studies have investigated the aetiological and prognostic factors of CHF, but there are only limited data on the role of precipitating factors that trigger relapse of CHF. Knowledge of potential precipitating factors may help to optimise treatment and provide guidance for patients with CHF. The literature was reviewed to identify factors that may influence haemodynamic homeostasis in CHF. Precipitating factors that may offer opportunities for preventing relapse of CHF were selected. Potential precipitating factors are discussed in relation to the pathophysiology of CHF: alcohol, smoking, psychological stress, uncontrolled hypertension, cardiac arrhythmias, myocardial ischaemia, poor treatment compliance, and inappropriate medical treatment. Poor treatment compliance in particular is frequently encountered in patients with CHF. Furthermore, studies of medical treatment under everyday circumstances indicate that some aspects of the management of CHF can be improved. In conclusion, the identification of precipitating factors for relapse of CHF may strongly contribute to optimal treatment. Improvement of treatment compliance and optimalisation of medical treatment may offer important possibilities to clinicians to reduce the number of relapses in patients with CHF. Keywords: congestive heart failure; precipitating factors; prevention PMID:9930039
Wang, Yue; Luo, Jin; Hao, Shiying; Xu, Haihua; Shin, Andrew Young; Jin, Bo; Liu, Rui; Deng, Xiaohong; Wang, Lijuan; Zheng, Le; Zhao, Yifan; Zhu, Chunqing; Hu, Zhongkai; Fu, Changlin; Hao, Yanpeng; Zhao, Yingzhen; Jiang, Yunliang; Dai, Dorothy; Culver, Devore S; Alfreds, Shaun T; Todd, Rogow; Stearns, Frank; Sylvester, Karl G; Widen, Eric; Ling, Xuefeng B
2015-12-01
In order to proactively manage congestive heart failure (CHF) patients, an effective CHF case finding algorithm is required to process both structured and unstructured electronic medical records (EMR) to allow complementary and cost-efficient identification of CHF patients. We set to identify CHF cases from both EMR codified and natural language processing (NLP) found cases. Using narrative clinical notes from all Maine Health Information Exchange (HIE) patients, the NLP case finding algorithm was retrospectively (July 1, 2012-June 30, 2013) developed with a random subset of HIE associated facilities, and blind-tested with the remaining facilities. The NLP based method was integrated into a live HIE population exploration system and validated prospectively (July 1, 2013-June 30, 2014). Total of 18,295 codified CHF patients were included in Maine HIE. Among the 253,803 subjects without CHF codings, our case finding algorithm prospectively identified 2411 uncodified CHF cases. The positive predictive value (PPV) is 0.914, and 70.1% of these 2411 cases were found to be with CHF histories in the clinical notes. A CHF case finding algorithm was developed, tested and prospectively validated. The successful integration of the CHF case findings algorithm into the Maine HIE live system is expected to improve the Maine CHF care. Copyright © 2015. Published by Elsevier Ireland Ltd.
Griffo, Raffaele; Spanevello, Antonio; Temporelli, Pier Luigi; Faggiano, Pompilio; Carone, Mauro; Magni, Giovanna; Ambrosino, Nicolino; Tavazzi, Luigi
2017-04-01
Background Chronic heart failure (CHF) and chronic obstructive pulmonary disease (COPD) frequently coexist but concurrent COPD + CHF has been little investigated. Design This multicentre survey (SUSPIRIUM) was designed to evaluate: the prevalence of COPD in stable CHF and CHF in stable COPD; diagnostic/therapeutic work-up for concurrent COPD + CHF; clinical profile of patients with COPD + CHF; predictors of COPD in CHF and CHF in COPD. Methods A 5-month-long cross-sectional prospective observational survey was conducted in 10 cardiac and 10 respiratory connected outpatient units. Results The prevalence of CHF in the 378 surveyed COPD patients was 11.9% (95% confidence interval 8.8-16.6) and the prevalence of COPD in 375 CHF patients was 31.5% (95% confidence interval 26.8-36.4). Diagnostic tests for suspected comorbidity were prescribed in 21.6% and 22.9% of COPD and CHF patients, respectively. Patients with coexisting CHF + COPD had a higher incidence of hypertension, physical inactivity and more frequently a GOLD score of 3 or greater. Compared to CHF only, CHF + COPD patients were significantly older, more frequently smokers, at worse respiratory risk and in a higher New York Heart Association class. Conversely, hypercholesterolaemia, a family history of ischaemic heart disease, fluid retention and comorbidities were more frequent in COPD + CHF than COPD-only patients. At multivariate analysis, a GOLD score of 3 or greater in CHF strongly predicted coexistent COPD (odds ratio 8.985, P < 0.0001) as did a history of other respiratory diseases (5.184, P < 0.0001). A history of ischaemic heart disease (4.868, P < 0.0001), atrial fibrillation (3.302, P < 0.0001) and sedentary lifestyle (2.814, P < 0.004) predicted coexistent CHF in COPD. Conclusion The high prevalence of COPD + CHF calls for integrated disease management between cardiologists and pulmonologists. SUSPIRIUM identifies which cardiac/pulmonary outpatients should be screened for the respective comorbidity.
Juillière, Yves; Suty-Selton, Christine; Riant, Elisabeth; Darracq, Jean-Pierre; Dellinger, Arnaud; Labarre, Jean-Philippe; Druelle, Justine; Mulak, Geneviève; Danchin, Nicolas; Jourdain, Patrick
2014-01-01
Chronic heart failure (CHF) is a frequent severe disease. Disease-management programmes, which contain a therapeutic patient education component, will play a central role in improving delivery of care and reducing mortality and hospitalizations for CHF. In order to have an up-to-date overview of medical treatment of CHF in France implemented by hospital and clinic cardiologists especially interested in CHF and therapeutic patient education, we described the prescription of cardiovascular drugs in the large ODIN cohort of CHF patients, according to age and type of CHF. From 2007 to 2010 (median follow-up 27.2 months), CHF patients were prospectively enrolled in a multicentre 'real-world' French cohort by centres previously trained in therapeutic patient education. Patients were grouped according to age (< 60 years, 60 to<70 years, 70 to<80 years and ≥ 80 years) and type of CHF (characterized by level of LVEF: reduced, borderline or preserved). Medical prescription was described and mortality was assessed at long-term follow-up. The cohort consisted of 3237 patients (67.6 years; 69.4% men). The oldest age group had the highest LVEF. Blockers of the angiotensin-aldosterone system were prescribed progressively and significantly less frequently as the population advanced in age or as LVEF was more preserved. The mean dosages of the main prescribed CHF drugs remained ≥ 50% lower than those recommended for most drugs in all age and LVEF groups. Drug prescriptions were related to aetiology of reduced or preserved CHF. A global decrease in CHF drug prescription was observed for all medication classes except calcium blockers, according to maintenance of relatively or totally preserved LVEF. Survival was related to age but not to type of CHF. In CHF, and despite management by cardiologists particularly interested in CHF and specifically trained to deliver therapeutic patient education, medical prescription differed substantially from guidelines. Age and type of CHF (reduced versus preserved) appeared to be important factors in lack of adherence to guidelines. However, only age influenced mortality; the type of CHF did not affect survival. Copyright © 2013 Elsevier Masson SAS. All rights reserved.
Effects of moderate heart failure and functional overload on rat plantaris muscle
NASA Technical Reports Server (NTRS)
Spangenburg, Espen E.; Lees, Simon J.; Otis, Jeff S.; Musch, Timothy I.; Talmadge, Robert J.; Williams, Jay H.
2002-01-01
It is thought that changes in sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA) of skeletal muscle contribute to alterations in skeletal muscle function during congestive heart failure (CHF). It is well established that exercise training can improve muscle function. However, it is unclear whether similar adaptations will result from exercise training in a CHF patient. Therefore, the purpose of this study was to determine whether skeletal muscle during moderate CHF adapts to increased activity, utilizing the functional overload (FO) model. Significant increases in plantaris mass of the CHF-FO and sham-FO groups compared with the CHF and control (sham) groups were observed. Ca(2+) uptake rates were significantly elevated in the CHF group compared with all other groups. No differences were detected in Ca(2+) uptake rates between the CHF-FO, sham, and sham-FO groups. Increases in Ca(2+) uptake rates in moderate-CHF rats were not due to changes in SERCA isoform proportions; however, FO may have attenuated the CHF-induced increases through alterations in SERCA isoform expression. Therefore, changes in skeletal muscle Ca(2+) handling during moderate CHF may be due to alterations in regulatory mechanisms, which exercise may override, by possibly altering SERCA isoform expression.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Koehler, W; Hein, D
1986-09-01
The influence of the wetting state of a heated surface on heat transfer and pressure loss in an evaporator tube was investigated for a parameter range occurring in fossil-fired steam generators. Included in the analysis are quantities which determine the wetting state in steady and transient flow. The experimental work consists of the following: Occurrence of critical heat flux (CHF) and post-CHF heat transfer in a vertical upflow evaporator tube; influence of pressure and enthalpy transients on heat transfer in the unwetted region; influence of pipe orientation on heat transfer; and two phase flow pressure loss in wetted and unwettedmore » region. Based on these experiments a method of predicting CHF for a vertical upflow evaporator tube was developed. The heat transfer in the unwetted region was newly formulated taking into account thermal nonequilibrium between the water and steam phases. Wall temperature excursions during pressure and enthalpy transients are interpreted with the help of the boiling curve and the Leidenfrost phenomenon. A method is developed by means of which it is possible to determine the influence of the pipe orientation on the location of the boiling crisis as well as on the heat transfer in the unwetted region. The influence of the wetting state of the heated surface on the two phase flow pressure loss is interpreted as ''Wall effect'' and is calculated using a simplified computer model. 68 refs., 83 figs.« less
Gomes-Santos, Igor Lucas; Fernandes, Tiago; Couto, Gisele Kruger; Ferreira-Filho, Julio César Ayres; Salemi, Vera Maria Cury; Fernandes, Fernanda Barrinha; Casarini, Dulce Elena; Brum, Patricia Chakur; Rossoni, Luciana Venturini; de Oliveira, Edilamar Menezes; Negrao, Carlos Eduardo
2014-01-01
Accumulated evidence shows that the ACE-AngII-AT1 axis of the renin-angiotensin system (RAS) is markedly activated in chronic heart failure (CHF). Recent studies provide information that Angiotensin (Ang)-(1-7), a metabolite of AngII, counteracts the effects of AngII. However, this balance between AngII and Ang-(1-7) is still little understood in CHF. We investigated the effects of exercise training on circulating and skeletal muscle RAS in the ischemic model of CHF. Male Wistar rats underwent left coronary artery ligation or a Sham operation. They were divided into four groups: 1) Sedentary Sham (Sham-S), 2) exercise-trained Sham (Sham-Ex), sedentary CHF (CHF-S), and exercise-trained CHF (CHF-Ex). Angiotensin concentrations and ACE and ACE2 activity in the circulation and skeletal muscle (soleus and plantaris) were quantified. Skeletal muscle ACE and ACE2 protein expression, and AT1, AT2, and Mas receptor gene expression were also evaluated. CHF reduced ACE2 serum activity. Exercise training restored ACE2 and reduced ACE activity in CHF. Exercise training reduced plasma AngII concentration in both Sham and CHF rats and increased the Ang-(1-7)/AngII ratio in CHF rats. CHF and exercise training did not change skeletal muscle ACE and ACE2 activity and protein expression. CHF increased AngII levels in both soleus and plantaris muscle, and exercise training normalized them. Exercise training increased Ang-(1-7) in the plantaris muscle of CHF rats. The AT1 receptor was only increased in the soleus muscle of CHF rats, and exercise training normalized it. Exercise training increased the expression of the Mas receptor in the soleus muscle of both exercise-trained groups, and normalized it in plantaris muscle. Exercise training causes a shift in RAS towards the Ang-(1-7)-Mas axis in skeletal muscle, which can be influenced by skeletal muscle metabolic characteristics. The changes in RAS circulation do not necessarily reflect the changes occurring in the RAS of skeletal muscle.
Detection of Chamber Conditioning Through Optical Emission and Impedance Measurements
NASA Technical Reports Server (NTRS)
Cruden, Brett A.; Rao, M. V. V. S.; Sharma, Surendra P.; Meyyappan, Meyya
2001-01-01
During oxide etch processes, buildup of fluorocarbon residues on reactor sidewalls can cause run-to-run drift and will necessitate some time for conditioning and seasoning of the reactor. Though diagnostics can be applied to study and understand these phenomena, many of them are not practical for use in an industrial reactor. For instance, measurements of ion fluxes and energy by mass spectrometry show that the buildup of insulating fluorocarbon films on the reactor surface will cause a shift in both ion energy and current in an argon plasma. However, such a device cannot be easily integrated into a processing system. The shift in ion energy and flux will be accompanied by an increase in the capacitance of the plasma sheath. The shift in sheath capacitance can be easily measured by a common commercially available impedance probe placed on the inductive coil. A buildup of film on the chamber wall is expected to affect the production of fluorocarbon radicals, and thus the presence of such species in the optical emission spectrum of the plasma can be monitored as well. These two techniques are employed on a GEC (Gaseous Electronics Conference) Reference Cell to assess the validity of optical emission and impedance monitoring as a metric of chamber conditioning. These techniques are applied to experimental runs with CHF3 and CHF3/O2/Ar plasmas, with intermediate monitoring of pure argon plasmas as a reference case for chamber conditions.
DiBona, G F; Sawin, L L
1999-07-06
Long-term metoprolol therapy improves cardiac performance and decreases mortality in patients with chronic congestive heart failure (CHF). This study examined the effect of long-term metoprolol therapy on renal sodium handling in an experimental rat model of CHF. Rats with left coronary ligation and myocardial infarction-induced CHF were treated with metoprolol (1.5 mg. kg-1. h-1) or vehicle for 3 weeks by osmotic minipump. They were then evaluated for their ability to excrete a short-term sodium load (5% body weight isotonic saline infusion over 30 minutes) and a long-term sodium load (change from low- to high-sodium diet over 8 days). All CHF rats had left ventricular end-diastolic pressure >10 mm Hg, and heart weight/body weight ratios averaged 0.68+/-0.02% (versus control of approximately 0.40%). Compared with vehicle CHF rats (n=19), metoprolol CHF rats (n=18) had lower basal values of mean arterial pressure (122+/-3 versus 112+/-3 mm Hg) and heart rate (373+/-14 versus 315+/-9 bpm) and decreased heart rate responses to intravenous doses of isoproterenol. During short-term isotonic saline volume loading, metoprolol CHF rats excreted 54+/-4% more of the sodium load than vehicle CHF rats. During long-term dietary sodium loading, metoprolol CHF rats retained 28+/-3% less sodium than vehicle CHF rats. Metoprolol treatment of rats with CHF results in an improved ability to excrete both short- and long-term sodium loads.
Dungan, Kathleen; Graessle, Kari; Sagrilla, Colleen
2013-10-01
Congestive heart failure (CHF) features disturbances in the interstitial environment that may affect the accuracy of subcutaneous continuous glucose monitoring (CGM). A pooled analysis of two studies of hospitalized patients with type 2 diabetes randomized to intravenous or subcutaneous insulin was conducted. One study enrolled patients with CHF exacerbation, whereas history of CHF was an exclusion criterion in the other. All patients wore a professional CGM device for at least 24 h. Intravenous insulin was administered according to the institution's nursing-run protocol (duration of 12 and 48 h in non-CHF and CHF protocols, respectively). Subcutaneous insulin was delivered similarly in both groups. Subjects with CHF (n=43) had higher admission glucose and hemoglobin A1c compared with non-CHF subjects (n=32), but the sensor glucose values were similar. Overall mean absolute relative difference (MARD) was similar between CHF and non-CHF subjects (0.11 vs. 0.08, respectively; P=0.12). MARD was higher in the 100-149 mg/dL (P=0.003) and >199 mg/dL (P = 0.02) strata among CHF subjects. Static glucose and continuous glucose error grid analyses favored the non-CHF group. In multivariable analyses, only glucose coefficient of variation and log sensor time were independent predictors of elevated overall MARD >0.10. After adjustment for other factors, only increasing log sensor time was a significant predictor of elevated MARD in the 100-149 mg/dL strata. Among hospitalized subjects with type 2 diabetes, CHF exacerbation is not associated with lower sensor accuracy after adjustment for other factors, but this requires confirmation over a wider glucose range.
Lin, Tien-Yu; Huang, Yaw-Bin; Chen, Chung-Yu
2017-01-01
Objective β-Blockers are safe and improve survival in patients with both congestive heart failure (CHF) and COPD. However, the superiority of different types of β-blockers is still unclear among patients with CHF and COPD. The association between β-blockers and CHF exacerbation as well as COPD exacerbation remains unclear. The objective of this study was to compare the outcome of different β-blockers in patients with concurrent CHF and COPD. Patients and methods We used the National Health Insurance Research Database in Taiwan to conduct a retrospective cohort study. The inclusion criteria for CHF were patients who were >20 years old and were diagnosed with CHF between January 1, 2005 and December 31, 2012. COPD patients included those who had outpatient visit claims ≥2 times within 365 days or 1 claim for hospitalization with a COPD diagnosis. A time-dependent Cox proportional hazards regression model was applied to evaluate the effectiveness of β-blockers in the study population. Results We identified 1,872 patients with concurrent CHF and COPD. Only high-dose bisoprolol significantly reduced the risk of death and slightly decreased the hospitalization rate due to CHF exacerbation (death: adjusted hazard ratio [aHR] =0.51, 95% confidence interval [CI] =0.29–0.89; hospitalization rate due to CHF exacerbation: aHR =0.48, 95% CI =0.23–1.00). No association was observed between β-blocker use and COPD exacerbation. Conclusion In patients with concurrent CHF and COPD, β-blockers reduced mortality, CHF exacerbation, and the need for hospitalization. Bisoprolol was found to reduce mortality and CHF exacerbation compared to carvedilol and metoprolol. PMID:28894360
GRACE score predicts heart failure admission following acute coronary syndrome.
McAllister, David A; Halbesma, Nynke; Carruthers, Kathryn; Denvir, Martin; Fox, Keith A
2015-04-01
Congestive heart failure (CHF) is a common and preventable complication of acute coronary syndrome (ACS). Nevertheless, ACS risk scores have not been shown to predict CHF risk. We investigated whether the at-discharge Global Registry of Acute Coronary Events (GRACE) score predicts heart failure admission following ACS. Five-year mortality and hospitalization data were obtained for patients admitted with ACS from June 1999 to September 2009 to a single centre of the GRACE registry. CHF was defined as any admission assigned WHO International Classification of Diseases 10 diagnostic code I50. The hazard ratio (HR) for CHF according to GRACE score was estimated in Cox models adjusting for age, gender and the presence of CHF on index admission. Among 1,956 patients, CHF was recorded on index admission in 141 patients (7%), and 243 (12%) were admitted with CHF over 3.8 median years of follow-up. Compared to the lowest quintile, patients in the highest GRACE score quintile had more CHF admissions (116 vs 17) and a shorter time to first admission (1.2 vs 2.0 years, HR 9.87, 95% CI 5.93-16.43). Per standard deviation increment in GRACE score, the instantaneous risk was more than two-fold higher (HR 2.28; 95% CI 2.02-2.57), including after adjustment for CHF on index admission, age and gender (HR 2.49; 95% CI 2.06-3.02). The C-statistic for CHF admission at 1-year was 0.74 (95% CI 0.70-0.79). The GRACE score predicts CHF admission, and may therefore be used to target ACS patients at high risk of CHF with clinical monitoring and therapies. © The European Society of Cardiology 2014.
Graessle, Kari; Sagrilla, Colleen
2013-01-01
Abstract Background Congestive heart failure (CHF) features disturbances in the interstitial environment that may affect the accuracy of subcutaneous continuous glucose monitoring (CGM). Subjects and Methods A pooled analysis of two studies of hospitalized patients with type 2 diabetes randomized to intravenous or subcutaneous insulin was conducted. One study enrolled patients with CHF exacerbation, whereas history of CHF was an exclusion criterion in the other. All patients wore a professional CGM device for at least 24 h. Intravenous insulin was administered according to the institution's nursing-run protocol (duration of 12 and 48 h in non-CHF and CHF protocols, respectively). Subcutaneous insulin was delivered similarly in both groups. Results Subjects with CHF (n=43) had higher admission glucose and hemoglobin A1c compared with non-CHF subjects (n=32), but the sensor glucose values were similar. Overall mean absolute relative difference (MARD) was similar between CHF and non-CHF subjects (0.11 vs. 0.08, respectively; P=0.12). MARD was higher in the 100–149 mg/dL (P=0.003) and >199 mg/dL (P=0.02) strata among CHF subjects. Static glucose and continuous glucose error grid analyses favored the non-CHF group. In multivariable analyses, only glucose coefficient of variation and log sensor time were independent predictors of elevated overall MARD >0.10. After adjustment for other factors, only increasing log sensor time was a significant predictor of elevated MARD in the 100–149 mg/dL strata. Conclusions Among hospitalized subjects with type 2 diabetes, CHF exacerbation is not associated with lower sensor accuracy after adjustment for other factors, but this requires confirmation over a wider glucose range. PMID:24050738
Chronic heart failure management in Australia -- time for general practice centred models of care?
Scott, Ian; Jackson, Claire
2013-05-01
Chronic heart failure (CHF) is an increasingly prevalent problem within ageing populations and accounts for thousands of hospitalisations and deaths annually in Australia. Disease management programs for CHF (CHF-DMPs) aim to optimise care, with the predominant model being cardiologist led, hospital based multidisciplinary clinics with cardiac nurse outreach. However, findings from contemporary observational studies and clinical trials raise uncertainty around the effectiveness and sustainability of traditional CHF-DMPs in real-world clinical practice. To suggest an alternative model of care that involves general practitioners with a special interest in CHF liaising with, and being up-skilled by, specialists within community based, multidisciplinary general practice settings. Preliminary data from trials evaluating primary care based CHF-DMPs are encouraging, and further studies are underway comparing this model of care with traditional hospital based, specialist led CHF-DMPs. Results of studies of similar primary care models targeting diabetes and other chronic diseases suggest potential for its application to CHF.
NASA Astrophysics Data System (ADS)
Rajabzadeh Dareh, F.; Haghshenasfard, M.; Nasr Esfahany, M.; Salimi Jazi, H.
2018-06-01
Pool boiling heat transfer of pure water and nanofluids on a copper block has been studied experimentally. Nanofluids with various concentrations of 0.0025, 0.005 and 0.01 vol.% are employed and two simple surfaces (polished and machined copper surface) are used as the heating surfaces. The results indicated that the critical heat flux (CHF) in boiling of fluids on the polished surface is 7% higher than CHF on the machined surface. In the case of machined surface, the heat transfer coefficient (HTC) of 0.01 vol.% nanofluid is about 37% higher than HTC of base fluid, while in the polished surface the average HTC of 0.01% nanofluid is about 19% lower than HTC of the pure water. The results also showed that the boiling time and boiling cycles on the polished surface changes the heat transfer performance. By increasing the boiling time from 5 to 10 min, the roughness enhances about 150%, but by increasing the boiling time to 15 min, the roughness enhancement is only 8%.
General correlation for prediction of critical heat flux ratio in water cooled channels
DOE Office of Scientific and Technical Information (OSTI.GOV)
Pernica, R.; Cizek, J.
1995-09-01
The paper present the general empirical Critical Heat Flux Ration (CHFR) correlation which is valid for vertical water upflow through tubes, internally heated concentric annuli and rod bundles geometries with both wide and very tight square and triangular rods lattices. The proposed general PG correlation directly predicts the CHFR, it comprises axial and radial non-uniform heating, and is valid in a wider range of thermal hydraulic conditions than previously published critical heat flux correlations. The PG correlation has been developed using the critical heat flux Czech data bank which includes more than 9500 experimental data on tubes, 7600 data onmore » rod bundles and 713 data on internally heated concentric annuli. Accuracy of the CHFR prediction, statistically assessed by the constant dryout conditions approach, is characterized by the mean value nearing 1.00 and the standard deviation less than 0.06. Moverover, a subchannel form of the PG correlations is statistically verified on Westinghouse and Combustion Engineering rod bundle data bases, i.e. more than 7000 experimental CHF points of Columbia University data bank were used.« less
Abassi, Zaid A; Barac, Yaron D; Kostin, Sawa; Roguin, Ariel; Ovcharenko, Elena; Awad, Hoda; Blank, Ayelet; Bar-Am, Orit; Amit, Tamar; Schaper, Jutta; Youdim, Moussa; Binah, Ofer
2011-07-01
Despite the availability of many pharmacological and mechanical therapies, the mortality rate among patients with congestive heart failure (CHF) remains high. We tested the hypothesis that TVP1022 (the S-isomer of rasagiline; Azilect), a neuroprotective and cytoprotective molecule, is also cardioprotective in the settings of experimental CHF in rats. In rats with volume overload-induced CHF, we investigated the therapeutic efficacy of TVP1022 (7.5 mg/kg) on cardiac function, structure, biomarkers, and kidney function. Treatment with TVP1022 for 7 days before CHF induction prevented the increase in left ventricular end-diastolic area and end-systolic area, and the decrease in fractional shortening measured 14 days after CHF induction. Additionally, TVP1022 pretreatment attenuated CHF-induced cardiomyocyte hypertrophy, fibrosis, plasma and ventricular B-type natriuretic peptide levels, and reactive oxygen species expression. Further, in CHF rats, TVP1022 decreased cytochrome c and caspase 3 expression, thereby contributing to the cardioprotective efficacy of the drug. TVP1022 also enhanced the urinary Na(+) excretion and improved the glomerular filtration rate. Similar cardioprotective effects were obtained when TVP1022 was given to rats after CHF induction. TVP1022 attenuated the adverse functional, structural, and molecular alterations in CHF, rendering this drug a promising candidate for improving cardiac and renal function in this disease state.
Incremental burden of congestive heart failure among elderly with Alzheimer's.
Chhatre, Sumedha; Weiner, Mark G; Jayadevappa, Ravishankar; Johnson, Jerry C
2009-07-01
A complex relationship exists between Alzheimer's disease (AD) and other co-existing co-morbidities such as congestive heart failure (CHF) with implications for health resource utilization (HRU) and cost of care. Study objective was to assess HRU and cost of care in elderly with AD and with or without concomitant CHF. All elderly (> or =65 years) from an academic healthcare system diagnosed with AD in 1999 (n = 904) and matched AD-free controls (n = 3616). Each group was subdivided into those with and without a CHF diagnosis. Costs and HRU were obtained from Medicare databases for 1999 and 2000. Costs and HRU were compared using ANOVA and Wilcoxon rank sum tests. Regressions were used to model the effect of AD and CHF on outcomes. Mean annual cost were 20,888 US dollars for AD + CHF group, 5,473 US dollars for only AD group, 17,700 US dollars for only CHF group and 4,578 US dollars for the control group (no-AD and no-CHF). After adjusting for covariates, AD + CHF group had an eight-fold increase in total cost, while only CHF group had five-fold increase in total cost, compared to the control group. Regressions for inpatient costs, outpatient costs and inpatient pharmacy costs exhibited comparable trends. For elderly AD patients, a co-occurring diagnosis of CHF can result in a substantial increase in cost and HRU. This necessitates additional considerations if health care expenditures are to be reduced, particularly inpatient expenditure.
Relation of vitamin D status to congestive heart failure and cardiovascular events in dogs.
Kraus, M S; Rassnick, K M; Wakshlag, J J; Gelzer, A R M; Waxman, A S; Struble, A M; Refsal, K
2014-01-01
Vitamin D plays a pivotal role in cardiac function, and there is increasing evidence that vitamin D deficiency is associated with the development of congestive heart failure (CHF) in people. Serum vitamin D concentration is lower in dogs with CHF compared with unaffected controls and serum vitamin D concentration is associated with clinical outcome in dogs with CHF. Eighty-two client-owned dogs. In this cross-sectional study, we examined the association between circulating 25-hydroxyvitamin D [25(OH)D], a measure of vitamin D status, and CHF in dogs. In the prospective cohort study, we examined whether 25(OH)D serum concentration was associated with clinical outcome in dogs with CHF. Mean 25(OH)D concentration (100 ± 44 nmol/L) in 31 dogs with CHF was significantly lower than that of 51 unaffected dogs (123 ± 42 nmol/L; P = .023). The mean calculated vitamin D intake per kg of metabolic body weight in dogs with CHF was no different from that of unaffected dogs (1.37 ± 0.90 μg/kg metabolic body weight versus 0.98 ± 0.59 μg/kg body weight, respectively, P = .097). There was a significant association of serum 25(OH)D concentration on time to clinical manifestation of CHF or sudden death (P = .02). These findings suggest that low concentrations of 25(OH)D may be a risk factor for CHF in dogs. Low serum 25(OH)D concentration was associated with poor outcome in dogs with CHF. Strategies to improve vitamin D status in some dogs with CHF may prove beneficial without causing toxicity. Copyright © 2013 by the American College of Veterinary Internal Medicine.
Hemodynamic and neurochemical determinates of renal function in chronic heart failure.
Gilbert, Cameron; Cherney, David Z I; Parker, Andrea B; Mak, Susanna; Floras, John S; Al-Hesayen, Abdul; Parker, John D
2016-01-15
Abnormal renal function is common in acute and chronic congestive heart failure (CHF) and is related to the severity of congestion. However, treatment of congestion often leads to worsening renal function. Our objective was to explore basal determinants of renal function and their response to hemodynamic interventions. Thirty-seven patients without CHF and 59 patients with chronic CHF (ejection fraction; 23 ± 8%) underwent right heart catheterization, measurements of glomerular filtration rate (GFR; inulin) and renal plasma flow (RPF; para-aminohippurate), and radiotracer estimates of renal sympathetic activity. A subset (26 without, 36 with CHF) underwent acute pharmacological intervention with dobutamine or nitroprusside. We explored the relationship between baseline and drug-induced hemodynamic changes and changes in renal function. In CHF, there was an inverse relationship among right atrial mean pressure (RAM) pressure, RPF, and GFR. By contrast, mean arterial pressure (MAP), cardiac index (CI), and measures of renal sympathetic activity were not significant predictors. In those with CHF there was also an inverse relationship among the drug-induced changes in RAM as well as pulmonary artery mean pressure and the change in GFR. Changes in MAP and CI did not predict the change in GFR in those with CHF. Baseline values and changes in RAM pressure did not correlate with GFR in those without CHF. In the CHF group there was a positive correlation between RAM pressure and renal sympathetic activity. There was also an inverse relationship among RAM pressure, GFR, and RPF in patients with chronic CHF. The observation that acute reductions in RAM pressure is associated with an increase in GFR in patients with CHF has important clinical implications. Copyright © 2016 the American Physiological Society.
Ziehm, Jeanette; Farin, Erik; Seibel, Katharina; Becker, Gerhild; Köberich, Stefan
2016-08-15
Even though struggling with similar symptom burden, patients with chronic heart failure (CHF) receive less palliative care than patients suffering from malignant diseases. Researchers have found that this might be related to lack of knowledge about palliative care, insufficient interprofessional communication as well as the cyclic course of disease which makes accurate prognosis difficult. However, research findings have shown that patients with CHF benefit from palliative care. As there are no studies for the German health care system this study aimed to assess health care professionals' attitudes regarding palliative care of CHF patients in order to identify barriers and facilitators for this patient group and hence to develop recommendations for improvement of CHF patients' access to palliative care in Germany. Problem-centered interviews with 23 health care professionals involved in care of CHF patients (nurses: hospital, outpatient, heart failure, PC; physicians: hospital and resident cardiologists, general practitioners) were conducted and analysed according to Mayring's qualitative content analysis. Most interviewees perceived a need for palliative care for CHF patients. Regarding barriers patients', public's, and professionals' lack of knowledge of palliative care and CHF; shortcomings in communication and cooperation of different professional groups; inability of cardiology to accept medical limits; difficult prognosis of course of disease; and patients' concerns regarding palliative care were described. Different attitudes regarding appropriate time of initiation of palliative care for CHF patients (late vs. early) were found. Furthermore, better communication and closer cooperation between different professional groups and medical disciplines as well as better education about palliative care and CHF for professionals, patients, and public were cited. Palliative care for CHF patients is a neglected topic in both practice and research and should receive more attention. Barriers to palliative care for CHF patients might be overcome by: better education for the public, patients, and professionals, closer cooperation between the different professional groups involved as well as development of a joint agreement regarding the appropriate time to administer palliative care to CHF patients. DRKS00007119 .
Urinary Proteolytic Activation of Renal Epithelial Na+ Channels in Chronic Heart Failure.
Zheng, Hong; Liu, Xuefei; Sharma, Neeru M; Li, Yulong; Pliquett, Rainer U; Patel, Kaushik P
2016-01-01
One of the key mechanisms involved in renal Na(+) retention in chronic heart failure (CHF) is activation of epithelial Na(+) channels (ENaC) in collecting tubules. Proteolytic cleavage has an important role in activating ENaC. We hypothesized that enhanced levels of proteases in renal tubular fluid activate ENaC, resulting in renal Na(+) retention in rats with CHF. CHF was produced by left coronary artery ligation in rats. By immunoblotting, we found that several urinary serine proteases were significantly increased in CHF rats compared with sham rats (fold increases: furin 6.7, prostasin 23.6, plasminogen 2.06, and plasmin 3.57 versus sham). Similar increases were observed in urinary samples from patients with CHF. Whole-cell patch clamp was conducted in cultured renal collecting duct M-1 cells to record Na(+) currents. Protease-rich urine (from rats and patients with CHF) significantly increased the Na(+) inward current in M-1 cells. Two weeks of protease inhibitor treatment significantly abrogated the enhanced diuretic and natriuretic responses to ENaC inhibitor benzamil in rats with CHF. Increased podocyte lesions were observed in the kidneys of rats with CHF by transmission electron microscopy. Consistent with these results, podocyte damage markers desmin and podocin expressions were also increased in rats with CHF (increased ≈2-folds). These findings suggest that podocyte damage may lead to increased proteases in the tubular fluid, which in turn contributes to the enhanced renal ENaC activity, providing a novel mechanistic insight for Na(+) retention commonly observed in CHF. © 2015 American Heart Association, Inc.
Urinary proteolytic activation of renal epithelial Na+ channels in chronic heart failure
Zheng, Hong; Liu, Xuefei; Sharma, Neeru M.; Li, Yulong; Pliquett, Rainer U; Patel, Kaushik P.
2015-01-01
One of the key mechanisms involved in renal Na+ retention in chronic heart failure (CHF) is activation of epithelial Na+ channels (ENaC) in collecting tubules. Proteolytic cleavage has an important role in activating ENaC. We hypothesized that enhanced levels of proteases in renal tubular fluid activate ENaC resulting in renal Na+ retention in rats with CHF. CHF was produced by left coronary artery ligation in rats. By immunoblotting, we found that several urinary serine proteases were significantly increased in CHF rats compared to sham rats (fold increases: furin 6.7, prostasin 23.6, plasminogen 2.06 and plasmin 3.57 vs. sham). Similar increases were observed in urinary samples from patients with CHF. Whole-cell patch-clamp was conducted in cultured renal collecting duct M-1 cells to record Na+ currents. Protease-rich urine (from rats and patients with CHF) significantly increased the Na+ inward current in M-1 cells. Two weeks of protease inhibitor treatment significantly abrogated the enhanced diuretic and natriuretic responses to ENaC inhibitor benzamil in rats with CHF. Increased podocyte lesions were observed in the kidneys of rats with CHF by transmission electron microscopy. Consistent with these results, podocyte damage markers desmin and podocin expressions were also increased in rats with CHF (increased ~2 folds). These findings suggest that podocyte damage may lead to increased proteases in the tubular fluid which in turn contributes to the enhanced renal ENaC activity, providing a novel mechanistic insight for Na+ retention commonly observed in CHF. PMID:26628676
Chen, Jiqiu; Yaniz-Galende, Elisa; Kagan, Heather J.; Liang, Lifan; Hekmaty, Saboor; Giannarelli, Chiara
2015-01-01
The aim of the present study is to explore the role of capillary disorder in coronary ischemic congestive heart failure (CHF). CHF was induced in rats by aortic banding plus ischemia-reperfusion followed by aortic debanding. Coronary arteries were perfused with plastic polymer containing fluorescent dye. Multiple fluorescent images of casted heart sections and scanning electric microscope of coronary vessels were obtained to characterize changes in the heart. Cardiac function was assessed by echocardiography and in vivo hemodynamics. Stenosis was found in all levels of the coronary arteries in CHF. Coronary vasculature volume and capillary density in remote myocardium were significantly increased in CHF compared with control. This occurred largely in microvessels with a diameter of ≤3 μm. Capillaries in CHF had a tortuous structure, while normal capillaries were linear. Capillaries in CHF had inconsistent diameters, with assortments of narrowed and bulged segments. Their surfaces appeared rough, potentially indicating endothelial dysfunction in CHF. Segments of main capillaries between bifurcations were significantly shorter in length in CHF than in control. Transiently increasing preload by injecting 50 μl of 30% NaCl demonstrated that the CHF heart had lower functional reserve; this may be associated with congestion in coronary microcirculation. Ischemic coronary vascular disorder is not limited to the main coronary arteries, as it occurs in arterioles and capillaries. Capillary disorder in CHF included stenosis, deformed structure, proliferation, and roughened surfaces. This disorder in the coronary artery architecture may contribute to the reduction in myocyte contractility in the setting of heart failure. PMID:25659485
Heat Transfer Performances of Pool Boiling on Metal-Graphite Composite Surfaces
NASA Technical Reports Server (NTRS)
Zhang, Nengli; Chao, David F.; Yang, Wen-Jei
2000-01-01
Nucleate boiling, especially near the critical heat flux (CHF), can provide excellent economy along with high efficiency of heat transfer. However, the performance of nucleate boiling may deteriorate in a reduced gravity environment and the nucleate boiling usually has a potentially dangerous characteristic in CHF regime. That is, any slight overload can result in burnout of the boiling surface because the heat transfer will suddenly move into the film-boiling regime. Therefore, enhancement of nucleate boiling heat transfer becomes more important in reduced gravity environments. Enhancing nucleate boiling and critical heat flux can be reached using micro-configured metal-graphite composites as the boiling surface. Thermocapillary force induced by temperature difference between the graphite-fiber tips and the metal matrix, which is independent of gravity, will play an important role in bubble detachment. Thus boiling heat transfer performance does not deteriorate in a reduced-gravity environment. Based on the existing experimental data, and a two-tier theoretical model, correlation formulas are derived for nucleate boiling on the copper-graphite and aluminum-graphite composite surfaces, in both the isolated and coalesced bubble regimes. Experimental studies were performed on nucleate pool boiling of pentane on cooper-graphite (Cu-Gr) and aluminum-graphite (Al-Gr) composite surfaces with various fiber volume concentrations for heat fluxes up to 35 W per square centimeter. It is revealed that a significant enhancement in boiling heat transfer performance on the composite surfaces is achieved, due to the presence of micro-graphite fibers embedded in the matrix. The onset of nucleate boiling (the isolated bubble regime) occurs at wall superheat of about 10 C for the Cu-Gr surface and 15 C for the Al-Gr surface, much lower than their respective pure metal surfaces. Transition from an isolated bubble regime to a coalesced bubble regime in boiling occurs at a superheat of about 14 C on Cu-Gr surface and 19 C on Al-Gr surface.
Bartlett, Yvonne K; Haywood, Annette; Bentley, Claire L; Parker, Jack; Hawley, Mark S; Mountain, Gail A; Mawson, Susan
2014-11-25
Technology has the potential to provide support for self-management to people with congestive heart failure (CHF). This paper describes the results of a realist evaluation of the SMART Personalised Self-Management System (PSMS) for CHF. The PSMS was used, at home, by seven people with CHF. Data describing system usage and usability as well as questionnaire and interview data were evaluated in terms of the context, mechanism and outcome hypotheses (CMOs) integral to realist evaluation. The CHF PSMS improved heart failure related knowledge in those with low levels of knowledge at baseline, through providing information and quizzes. Furthermore, participants perceived the self-regulatory aspects of the CHF PSMS as being useful in encouraging daily walking. The CMOs were revised to describe the context of use, and how this influences both the mechanisms and the outcomes. Participants with CHF engaged with the PSMS despite some technological problems. Some positive effects on knowledge were observed as well as the potential to assist with changing physical activity behaviour. Knowledge of CHF and physical activity behaviour change are important self-management targets for CHF, and this study provides evidence to direct the further development of a technology to support these targets.
Increase in atmospheric CHF2Cl (HCFC-22) over southern California from 1985 to 1990
NASA Technical Reports Server (NTRS)
Irion, Fredrick W.; Brown, Margaret; Toon, Geoffrey C.; Gunson, Michael R.
1994-01-01
Column densities of CHF2Cl (HCFC-22) have been measured over Table Mountain Facility (TMF), Wrightwood, California (34.4 deg N) using the Atmospheric Trace Molecule Spectroscopy (ATMOS) Fourier-transform infrared (FTIR) spectrometer. Between October 1985 and July 1990, the exponential column increase rate was (6.7 +/- 0.5)%/yr. Additionally, column measurements of CHF2Cl over McMurdo Sound, Antarctica (78 deg S) in September and October 1986 by the MarkIV FTIR spectrometer were used to derive a south-north interhemispheric ratio of (0.86 +/- 0.08). Model calculations investigated the feasibility of using CHF2Cl column measurements with a predicted global OH field to determine a globally averaged chemical lifetime for CHF2Cl, or equivalently, an estimate of the OH field using a predicted lifetime. The current uncertainty in historical CHF2Cl emissions is too large for CHF2Cl to be used to infer adequately either the lifetime or the OH field.
Plasma sRAGE and N-(carboxymethyl) lysine in patients with CHF and/or COPD.
Boschetto, Piera; Campo, Ilaria; Stendardo, Mariarita; Casimirri, Enrico; Tinelli, Carmine; Gorrini, Marina; Ceconi, Claudio; Fucili, Alessandro; Potena, Alfredo; Papi, Alberto; Ballerin, Licia; Fabbri, Leonardo M; Luisetti, Maurizio
2013-06-01
Knowledge of the role of the receptor for advanced glycation end products (RAGE), particularly its soluble form (sRAGE), and of its advanced glycation end product (AGE) ligand, N-(carboxymethyl)lysine adducts (CML), is limited in chronic heart failure (CHF) and in chronic obstructive pulmonary disease (COPD). We evaluated whether the AGE/RAGE system is activated in stable CHF and COPD, and whether plasma sRAGE and CML levels are affected by clinical and functional parameters. We measured plasma levels of sRAGE and CML using a sandwich enzyme-linked immunosorbent assay (ELISA) in 143 subjects, aged ≥ 65 years, divided into five groups: 58 with CHF, 23 with COPD, 27 with CHF+COPD and 35 controls (17 healthy smokers and 18 healthy nonsmokers). Individuals with diabetes were excluded from the study. Plasma levels of sRAGE and CML were higher in CHF patients than in controls [sRAGE: 0.48 (0.37-0.83) vs. 0.42 (0.29-0.52) ng/mL, P = 0.01; CML: 1.95 (1.58-2.38) vs. 1.68 (1.43-2.00) ng/mL, P = 0.01]. By contrast, sRAGE and CML were not different between both COPD and CHF+COPD patients and controls (P > 0.05). N-terminal pro-brain natriuretic peptide (Nt-pro BNP) correlated with sRAGE, but not with CML, in the patient groups: CHF (r = 0.43, P < 0.001), COPD (r = 0.77, P < 0.0001) and CHF/COPD (r = 0.43, P = 0.003). Plasma levels of sRAGE and CML are increased in CHF, but not in COPD patients. The robust association between NT-pro BNP, a diagnostic and prognostic marker in CHF, and sRAGE concentrations might suggest a possible BNP pathway of amplification of inflammation via the AGE/RAGE system. © 2013 Stichting European Society for Clinical Investigation Journal Foundation. Published by John Wiley & Sons Ltd.
SP-B and SP-C Containing New Synthetic Surfactant for Treatment of Extremely Immature Lamb Lung
Sato, Atsuyasu; Ikegami, Machiko
2012-01-01
Although superiority of synthetic surfactant over animal-driven surfactant has been known, there is no synthetic surfactant commercially available at present. Many trials have been made to develop synthetic surfactant comparable in function to animal-driven surfactant. The efficacy of treatment with a new synthetic surfactant (CHF5633) containing dipalmitoylphosphatidylcholine, phosphatidylglycerol, SP-B analog, and SP-C analog was evaluated using immature newborn lamb model and compared with animal lung tissue-based surfactant Survanta. Lambs were treated with a clinical dose of 200 mg/kg CHF5633, 100 mg/kg Survanta, or air after 15 min initial ventilation. All the lambs treated with air died of respiratory distress within 90 min of age. During a 5 h study period, Pco2 was maintained at 55 mmHg with 24 cmH2O peak inspiratory pressure for both groups. The preterm newborn lamb lung functions were dramatically improved by CHF5633 treatment. Slight, but significant superiority of CHF5633 over Survanta was demonstrated in tidal volume at 20 min and dynamic lung compliance at 20 and 300 min. The ultrastructure of CHF5633 was large with uniquely aggregated lipid particles. Increased uptake of CHF5633 by alveolar monocytes for catabolism was demonstrated by microphotograph, which might be associated with the higher treatment dose of CHF5633. The higher catabolism of CHF5633 was also suggested by the similar amount of surfactant lipid in bronchoalveolar lavage fluid (BALF) between CHF5633 and Survanta groups, despite the 2-fold higher treatment dose of CHF5633. Under the present ventilation protocol, lung inflammation was minimal for both groups, evaluated by inflammatory cell numbers in BALF and expression of IL-1β, IL-6, IL-8, and TNFα mRNA in the lung tissue. In conclusion, the new synthetic surfactant CHF5633 was effective in treating extremely immature newborn lambs with surfactant deficiency during the 5 h study period. PMID:22808033
[Treatment motivation in patients with chronic cardiorenal syndrome].
Efremova, E V; Shutov, A M; Borodulina, E O
2015-01-01
To study treatment motivation in patients with chronic heart failure (CHF) and in those with CHF concurrent with chronic kidney disease (CKD). A total of 203 patients (130 men and 73 women; mean age, 61.8±9.6 years) with CHF diagnosed and assessed in accordance with the National Guidelines of the All-Russian Research Society of Cardiology and the Heart Failure Society for the diagnosis and treatment of CHF (third edition, 2009) were examined. CKD was diagnosed according to the 2012 National Guidelines of the Research Nephrology Society of Russia. A group of patients with chronic cardiorenal syndrome (CRS) included those with CHF and CKD with a glomerular filtration rate (GFR) of <60 ml/min/1.73 m2. The clinical course of CHF, personality profile, and motivation for non-drug and drug treatments were assessed in patients with chronic CRS. CFR was 67.7±17.2 ml/min/1.73 m2; chronic CRS was observed in 89 (44%) patients. Psychological functioning assessment showed that the patients with chronic CRS as compared with those with CHF without CKD had high anxiety and maladaptive disease attitudes. CHF treatment motivation (compliance with lifestyle modification and medication) was proved inadequate and detected only in 31 (15.3%) patients with CHF regardless of the presence of CKD. The specific features of psychological functioning, which affected treatment motivation, were seen in patients with chronic CRS: those who were lowly motivated had a euphoric attitude towards their disease (p=0.03); those who were satisfactorily motivated showed an emotive accentuation of character (p=0.002). The presence of CKD aggravates the clinical course of CHF and negatively affects the psychological functioning of patients with CHF. The patients with chronic CRS are characterized by a low level of motivation for both drug and non-drug treatments, which should be taken into account when managing this cohort of patients.
Zhang, Dongze; Liu, Jinxu; Zheng, Hong; Tu, Huiyin; Muelleman, Robert L.; Li, Yu-Long
2016-01-01
Impairment of arterial baroreflex sensitivity is associated with mortality in patients with chronic heart failure (CHF). Elevation of plasma angiotension II (Ang II) contributes to arterial baroreflex dysfunction in CHF. A reduced number of voltage-gated sodium (Nav) channels in aortic baroreceptor neurons are involved in CHF-blunted arterial baroreflex. In this study, we investigated acute effect of Ang II on Nav currents in the aortic baroreceptor neuron and on arterial baroreflex in sham and coronary artery ligation-induced CHF rats. Using Ang II 125I radioimmunoassay, real-time RT-PCR and western blot, we found that Ang II levels, and mRNA and protein expression of angiotension II type 1 receptor (AT1R) in nodose ganglia (NG) from CHF rats were higher than that from sham rats. Local microinjection of Ang II (0.2 nmol) into the NG decreased the arterial baroreflex sensitivity in sham rats, whereas losartan (1 nmol, an AT1R antagonist) improved the arterial baroreflex sensitivity in CHF rats. Data from patch-clamp recording showed that Ang II (100 nM) acutely inhibited Nav currents in the aortic baroreceptor neurons from sham and CHF rats. In particular, inhibitory effect of Ang II on Nav currents in the aortic baroreceptor neurons was larger in CHF rats than that in sham rats. Losartan (1 μM) totally abolished the inhibitory effect of Ang II on Nav currents in sham and CHF aortic baroreceptor neurons. These results suggest that elevation of endogenous Ang II in the NG contributes to impairment of the arterial baroreflex function in CHF rats through inhibiting Nav channels. PMID:25827427
Assessment of respiratory flow cycle morphology in patients with chronic heart failure.
Garde, Ainara; Sörnmo, Leif; Laguna, Pablo; Jané, Raimon; Benito, Salvador; Bayés-Genís, Antoni; Giraldo, Beatriz F
2017-02-01
Breathing pattern as periodic breathing (PB) in chronic heart failure (CHF) is associated with poor prognosis and high mortality risk. This work investigates the significance of a number of time domain parameters for characterizing respiratory flow cycle morphology in patients with CHF. Thus, our primary goal is to detect PB pattern and identify patients at higher risk. In addition, differences in respiratory flow cycle morphology between CHF patients (with and without PB) and healthy subjects are studied. Differences between these parameters are assessed by investigating the following three classification issues: CHF patients with PB versus with non-periodic breathing (nPB), CHF patients (both PB and nPB) versus healthy subjects, and nPB patients versus healthy subjects. Twenty-six CHF patients (8/18 with PB/nPB) and 35 healthy subjects are studied. The results show that the maximal expiratory flow interval is shorter and with lower dispersion in CHF patients than in healthy subjects. The flow slopes are much steeper in CHF patients, especially for PB. Both inspiration and expiration durations are reduced in CHF patients, mostly for PB. Using the classification and regression tree technique, the most discriminant parameters are selected. For signals shorter than 1 min, the time domain parameters produce better results than the spectral parameters, with accuracies for each classification of 82/78, 89/85, and 91/89 %, respectively. It is concluded that morphologic analysis in the time domain is useful, especially when short signals are analyzed.
Organizational structure for chronic heart failure and chronic obstructive pulmonary disease.
Rinne, Seppo T; Liu, Chuan-Fen; Wong, Edwin S; Hebert, Paul L; Heidenreich, Paul; Bastian, Lori A; Au, David H
2016-03-01
In contrast to chronic heart failure (CHF), measures of quality of care for chronic obstructive pulmonary disease (COPD) are poor. Our objective was to examine differences in organizational structure available to support quality of care for patients with CHF and COPD. We performed 2 nationwide surveys exploring organizational structure for the management of CHF and COPD. We surveyed the chief of medicine and the chief of cardiology and pulmonary medicine at 120 Veterans Affairs facilities in the United States. Analogous questions about organizational structure that enhanced adherence to guideline-based care were compared between CHF and COPD surveys. We found large and notable differences in the organizational structure for disease management, with systematically less attention given to COPD than CHF. These differences were evident in multiple processes of care. Key differences included fewer facilities: having COPD clinics than CHF clinics (12.7% vs 50.8%; P < .01), relating performance measures with COPD providers than CHF providers (17.1% vs 70%; P < .01), and having home monitoring programs for COPD than for CHF (50.5% vs 87.4%; P < .01). Despite the growing burden of COPD, less organizational structure existed for COPD than CHF. Lack of organizational structure for COPD likely impedes an organization's abilities to encourage high-quality care and avoid recently implemented hospital readmission penalties. Our results suggest the need to develop a systematic approach for healthcare systems to provide essential organizational structure based on the burden of disease in the population.
Efficacy of community-based multidisciplinary disease management of chronic heart failure.
Omar, A R; Suppiah, N; Chai, P; Chan, Y H; Seow, Y H; Quek, L L; Poh, K K; Tan, H C
2007-06-01
A multidisciplinary disease management (DM) programme in chronic heart failure (CHF) improves clinical outcome. The efficacy of such a programme in a heterogeneous Asian community is not well established. Therefore, we undertook the evaluation of the efficacy of the multidisciplinary community-based DM CHF programme. This was a prospective study involving 154 patients (54 percent male) with a primary diagnosis of CHF, New York Heart Association functional class III/IV CHF, with left ventricular ejection fraction (LVEF) less than 40 percent. The mean age was 65 +/- 12 years and mean LVEF was 27 +/- 9 percent. We evaluated CHF hospitalisation, quality of life, activity status and quality of care (percentage of patients who received ACE inhibitors/angiotensin receptor blockers (ARB) and beta blockers after a period of six months. At six months, there was improvement in the quality of life and activity status (p < 0.001). ACE inhibitors/ARB were maintained in 97 percent of the patients and there was an increased usage of beta blockers (p-value equals 0.001). The rate of CHF hospitalisation was reduced by 68 percent (p-value is less than 0.001) and there was no mortality. The multidisciplinary DM of CHF in a heterogeneous Asian community showed significant improvement in quality of life, quality of care and reduction in CHF hospitalisation.
Chronic heart failure in Japan: implications of the CHART studies.
Shiba, Nobuyuki; Shimokawa, Hiroaki
2008-01-01
The prognosis of patients with chronic heart failure (CHF) still remains poor, despite the recent advances in medical and surgical treatment. Furthermore, CHF is a major public health problem in most industrialized countries where the elderly population is rapidly increasing. Although the prevalence and mortality of CHF used to be relatively low in Japan, the disorder has been markedly increasing due to the rapid aging of the society and the Westernization of lifestyle that facilitates the development of coronary artery disease. The Chronic Heart Failure Analysis and Registry in the Tohoku District (CHART)-1 study was one of the largest cohorts in Japan. The study has clarified the characteristics and prognosis of Japanese patients with CHF, demonstrating that their prognosis was similarly poor compared with those in Western countries. However, we still need evidence for the prevention and treatment of CHF based on the large cohort studies or randomized treatment trials in the Japanese population. Since the strategy for CHF management is now changing from treatment to prevention, a larger-size prospective cohort, called the CHART-2 study, has been initiated to evaluate the risk factors of CHF in Japan. This review summarizes the current status of CHF studies in Japan and discusses their future perspectives.
A Competitive Kinetics Study of the Reaction of Cl with CS2 in Air at 298 K
NASA Technical Reports Server (NTRS)
Wallington, Timothy J.; Andino, Jean M.; Potts, Alan R.; Wine, Paul H.
1997-01-01
The relative rate technique has been used to investigate the kinetics of the reaction of Cl atoms with carbon disulfide, CS2, at 700 Torr total pressure of air at 298 K. The decay rate of CS2 was measured relative to CH4, CH3Cl and CHF2CL. For experiments using CH4 and CH3Cl references, the decay rate of CS2 was dependent on the ratio of the concentration of the reference to that of CS2. We ascribe this behavior to the generation of OH radicals in the system leading to complicated secondary chemistry. From experiments using CHF2Cl we are able to assign an upper limit of 4 x 10(exp -15) cu cm/(molecule s) for the overall reaction, Cl + CS2 yields products.
Pelle, Aline J; Schiffer, Angélique A; Smith, Otto R; Widdershoven, Jos W; Denollet, Johan
2010-06-25
Psychological risk factors for impaired health outcomes have been acknowledged in chronic heart failure (CHF), with Type D personality being such a risk factor. Inadequate consultation behavior, a specific aspect of self-management, might be one mechanism in explaining the adverse effect of Type D on health outcomes. In this study we examined the relationship between Type D personality, impaired disease-specific health status, and inadequate consultation behavior. CHF outpatients (n=313) completed the Type D Scale (DS14) at baseline, and the European Heart Failure Self-care Behaviour Scale (EHFScBS) and the Minnesota Living with Heart Failure Questionnaire (MLWHFQ) at 6-month follow-up. Type D personality independently predicted inadequate consultation behavior (OR=1.80, 95%CI [1.03-3.16], p=.04) and impaired health status (OR=3.61, 95%CI [1.93-6.74], p<.001) at 6-month follow-up, adjusting for demographic and clinical variables. Inadequate consultation behavior (OR=1.80, 95%CI [1.11-2.94], p=.02) and NYHA-class (OR=2.83, 95%CI [1.17-4.71], p<.001) were associated with impaired health status, after controlling for demographics, clinical variables, and Type D personality. Post-hoc multivariable analysis pointed out that Type D patients who displayed inadequate consultation behavior were at a 6-fold increased risk of reporting impaired health status, compared to the reference group of non-Type D patients who displayed adequate consultation behavior (OR=6.06, 95%CI [2.53-14.52], p<.001). These findings provide evidence for inadequate behavior as a mechanism that may explain the link between Type D personality and impaired health status. Future studies are warranted to elaborate on these findings. Copyright 2008 Elsevier Ireland Ltd. All rights reserved.
Millucci, Lia; Paccagnini, Eugenio; Ghezzi, Lorenzo; Bernardini, Giulia; Braconi, Daniela; Laschi, Marcella; Consumi, Marco; Spreafico, Adriano; Tanganelli, Piero; Lupetti, Pietro; Magnani, Agnese; Santucci, Annalisa
2011-01-01
Aims Atrial Natriuretic Peptide (ANP)-containing amyloid is frequently found in the elderly heart. No data exist regarding ANP aggregation process and its link to pathologies. Our aims were: i) to experimentally prove the presumptive association of Congestive Heart Failure (CHF) and Isolated Atrial Amyloidosis (IAA); ii) to characterize ANP aggregation, thereby elucidating IAA implication in the CHF pathogenesis. Methods and Results A significant prevalence (85%) of IAA was immunohistochemically proven ex vivo in biopsies from CHF patients. We investigated in vitro (using Congo Red, Thioflavin T, SDS-PAGE, transmission electron microscopy, infrared spectroscopy) ANP fibrillogenesis, starting from α-ANP as well as the ability of dimeric β-ANP to promote amyloid formation. Different conditions were adopted, including those reproducing β-ANP prevalence in CHF. Our results defined the uncommon rapidity of α-ANP self-assembly at acidic pH supporting the hypothesis that such aggregates constitute the onset of a fibrillization process subsequently proceeding at physiological pH. Interestingly, CHF-like conditions induced the production of the most stable and time-resistant ANP fibrils suggesting that CHF affected people may be prone to develop IAA. Conclusions We established a link between IAA and CHF by ex vivo examination and assessed that β-ANP is, in vitro, the seed of ANP fibrils. Our results indicate that β-ANP plays a crucial role in ANP amyloid deposition under physiopathological CHF conditions. Overall, our findings indicate that early IAA-related ANP deposition may occur in CHF and suggest that these latter patients should be monitored for the development of cardiac amyloidosis. PMID:21814559
Yamaguchi, Fuminari; Kawana, Ken-ichiro; Tanonaka, Kouichi; Kamano, Isamu; Igarashi, Takahiro; Gen, Eigyoku; Fujimoto, Yoko; Maki, Toshiyuki; Sanbe, Atsushi; Nasa, Yoshihisa; Takeo, Satoshi
1999-01-01
The effects of long-term treatment with trandolapril, an angiotensin I-converting enzyme inhibitor, on exercise capacity of rats with chronic heart failure (CHF) following coronary artery ligation were examined. CHF was developed by 8 weeks after the coronary artery ligation. The running time of rats with CHF in the treadmill test was shortened to approximately 65% of that of sham-operated rats (16.3±1.2 vs 25.1±1.6 min, n=7; P<0.05). ATP, creatine phosphate (CP), and lactate contents of the gracilis muscle of rats with CHF were similar to those of sham-operated rats before running. After running, ATP and CP were decreased and lactate was increased in both rats with CHF and sham-operated rats. There were no significant differences in the levels of energy metabolites between rats with CHF and sham-operated rats. The rates of decrease in ATP and CP and rate of increase in lactate in the gracilis muscle of rats with CHF during exercise were greater than those of sham operated rats (2.5, 2.0 and 1.5 fold high, respectively), suggesting wastage of energy during exercise in the animals with CHF. Myofibrillar Ca2+-stimulated ATPase (Ca-ATPase) activity of skeletal muscle of rats with CHF was increased over that of the sham-operated control (62.03±1.88 vs 52.34±1.19 μmol Pi mg−1 protein h−1 n=7; P<0.05). The compositions of myosin heavy chain (MHC) isoforms of gracilis muscle were altered by CHF; decreases in MHC types I and IIb and an increase in MHC type IIa were found (P<0.05). Rats with CHF were treated with 1 mg kg−1 day−1 trandolapril from the 2nd to 8th week after surgery. Treatment with trandolapril prolonged the running time, reversed the rates of decrease in ATP and CP and the rate of increase in lactate, and restored the Ca-ATPase activity (51.11±0.56 μmol Pi mg−1 protein h−1, n=7; P<0.05) and composition ratio of MHC isoforms in the gracilis muscle. The results suggest that long-term trandolapril treatment of rats with CHF may restore their ability to utilize energy without wastage and thus improve exercise capacity. PMID:10323590
Ryanodine Receptor Calcium Leak in Circulating B-Lymphocytes as a Biomarker in Heart Failure.
Kushnir, Alexander; Santulli, Gaetano; Reiken, Steven R; Coromilas, Ellie; Godfrey, Sarah J; Brunjes, Danielle L; Colombo, Paolo C; Yuzefpolskaya, Melana; Sokol, Seth I; Kitsis, Richard N; Marks, Andrew R
2018-03-28
Background -Advances in congestive heart failure (CHF) management depend on biomarkers for monitoring disease progression and therapeutic response. During systole, intracellular Ca2 + is released from the sarcoplasmic reticulum (SR) into the cytoplasm through type 2 ryanodine receptor/Ca2 + release channels (RyR2). In CHF, chronically elevated circulating catecholamine levels cause pathologic remodeling of RyR2 resulting in diastolic SR Ca2 + leak, and decreased myocardial contractility. Similarly, skeletal muscle contraction requires SR Ca2 + release through type-1 ryanodine receptors (RyR1), and chronically elevated catecholamine levels in CHF cause RyR1 mediated SR Ca2 + leak, contributing to myopathy and weakness. Circulating B-lymphocytes express RyR1 and catecholamine responsive signaling cascades, making them a potential surrogate for defects in intracellular Ca2 + handling due to leaky RyR channels in CHF. Methods -Whole blood was collected from patients with CHF, CHF status-post left-ventricular assist devices (LVAD), and controls. Blood was also collected from mice with ischemic CHF, ischemic CHF + S107 (a drug that specifically reduces RyR channel Ca2 + leak), and WT controls. Channel macromolecular complex was assessed by immunostaining RyR1 immunoprecipitated from lymphocyte enriched preparations. RyR1 Ca2 + leak was assessed using flow cytometry to measure Ca2 + fluorescence in B-lymphocytes, in the absence and presence of RyR1 agonists that empty RyR1 Ca2 + stores within the endoplasmic reticulum (ER). Results -Circulating B-lymphocytes from humans and mice with CHF exhibited remodeled RyR1 and decreased ER Ca2 + stores, consistent with chronic intracellular Ca2 + leak. This Ca2 + leak correlated with circulating catecholamine levels. The intracellular Ca2 + leak was significantly reduced in mice treated with the Rycal S107. CHF patients treated with LVAD exhibited a heterogeneous response. Conclusions -In CHF, B-lymphocytes exhibit remodeled leaky RyR1 channels and decreased ER Ca2 + stores consistent with chronic intracellular Ca2 + leak. RyR1 mediated Ca2 + leak in B-lymphocytes assessed using flow cytometry provides a surrogate measure of intracellular Ca2 + handling and systemic sympathetic burden, presenting a novel biomarker for monitoring response to pharmacologic and mechanical CHF therapy.
Interaction of excited He and Ne rare gas metastable atoms with the CHF2Cl molecule
NASA Astrophysics Data System (ADS)
Chérid, M.; Ben Arfa, M.; Driss Khodja, M.
2005-06-01
We studied the Penning ionization of the CHF2Cl molecule with He and Ne metastable atoms (He* and Ne*). We measured the electron kinetic energy and the time-of-flight mass spectra; we also determined the branching ratio for the parent ion and charged CHF+2, CHFCl+, HCF+/CF+ and Cl+ fragments. These data led us to discuss the dissociation channels for all the energetically-accessible electronic states of the ionized molecule. We evidenced a marked contrast in the fragment ion proportions for Ne*-CHF2Cl and He*-CHF2Cl systems, and related it to the difference in polarizability and internal energy of the He* and Ne* atoms.
The renal nerves in chronic heart failure: efferent and afferent mechanisms
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
Effect of Running Parameters on Flow Boiling Instabilities in Microchannels.
Zong, Lu-Xiang; Xu, Jin-Liang; Liu, Guo-Hua
2015-04-01
Flow boiling instability (FBI) in microchannels is undesirable because they can induce the mechanical vibrations and disturb the heat transfer characteristics. In this study, the synchronous optical visualization experimental system was set up. The pure acetone liquid was used as the working fluid, and the parallel triangle silicon microchannel heat sink was designed as the experimental section. With the heat flux ranging from 0-450 kW/m2 the microchannel demand average pressure drop-heater length (Δp(ave)L) curve for constant low mass flux, and the demand pressure drop-mass flux (Δp(ave)G) curve for constant length on main heater surface were obtained and studied. The effect of heat flux (q = 188.28, 256.00, and 299.87 kW/m2), length of main heater surface (L = 4.5, 6.25, and 8.00 mm), and mass flux (G = 188.97, 283.45, and 377.94 kg/m2s) on pressure drops (Ap) and temperatures at the central point of the main heater surface (Twc) were experimentally studied. The results showed that, heat flux, length of the main heater surface, and mass flux were identified as the important parameters to the boiling instability process. The boiling incipience (TBI) and critical heat flux (CHF) were early induced for the lower mass flux or the main heater surface with longer length. With heat flux increasing, the pressure drops were linearly and slightly decreased in the single liquid region but increased sharply in the two phase flow region, in which the flow boiling instabilities with apparent amplitude and long period were more easily triggered at high heat flux. Moreover, the system pressure was increased with the increase of the heat flux.
Increased Rho kinase activity in congestive heart failure
Dong, Ming; Liao, James K.; Fang, Fang; Lee, Alex Pui-Wai; Yan, Bryan Ping-Yen; Liu, Ming; Yu, Cheuk-Man
2012-01-01
Aims Rho kinases (ROCKs) are the best characterized effectors of the small G-protein RhoA, and play a role in enhanced vasoconstriction in animal models of congestive heart failure (CHF). This study examined if ROCK activity is increased in CHF and how it is associated with the outcome in CHF. Methods and results Patients admitted with CHF (n =178), disease controls (n =31), and normal subjects (n =30) were studied. Baseline ROCK activity was measured by phosphorylation of themyosin-binding subunit in peripheral leucocytes. The patients were followed up for 14.4 ± 7.2 months (range 0.5–26 months) or until the occurrence of cardiac death. The ROCK activity in CHF patients (2.93 ± 0.87) was significantly higher than that of the disease control (2.06 ± 0.38, P < 0.001) and normal control (1.57 ± 0.43, P < 0.001) groups. Similarly, protein levels of ROCK1 and ROCK2 as well as the activity of RhoA in CHF were significantly higher than in disease controls and normal controls (all P < 0.05). Dyspnoea at rest (β =0.338, P < 0.001), low left ventricular ejection fraction (β = –0.277, P < 0.001), and high creatinine (β =0.202, P =0.006) were independent predictors of the baseline ROCK activity in CHF. Forty-five patients died within 2 years follow-up (25.3%). Combining ROCK activity and N-terminal pro brain natriuretic peptide (NT-proBNP) had an incremental value (log rank χ2 =11.62) in predicting long-term mortality when compared with only NT-proBNP (log rank χ2 =5.16, P < 0.05). Conclusion ROCK activity is increased in CHF and it might be associated with the mortality in CHF. ROCK activity might be a complementary biomarker to CHF risk stratification. PMID:22588320
The Occurrence of Cheyne–Stokes Respiration in Congestive Heart Failure: The Effect of Age
Peer, Avivit; Lorber, Abraham; Suraiya, Suheir; Malhotra, Atul; Pillar, Giora
2010-01-01
Introduction: Up to 50% of adults with congestive heart failure (CHF) and left ventricular dysfunction demonstrate Cheyne–Stokes respiration (CSR), although the mechanisms remain controversial. Because CSR has been minimally studied in children, we sought to assess the prevalence of CSR in children with low and high output cardiac failure. We hypothesized that the existence of CSR only in children with low output CHF would support the importance of circulatory delay as a CSR mechanism. Methods: Thirty patients participated: 10 children with CHF, 10 matched children with no heart disease, and 10 adults with CHF. All participants underwent an in-laboratory polysomnographic sleep study. Results: CHF children's average age (±SEM) was 3.6 ± 2.1 years vs. 3.7 ± 2 years in the age-matched control group. The average ejection fraction of three children with low output CHF was 22 ± 6.8%. The remaining seven had normal-high cardiac output. Compared to control children, CHF children were tachypneic and tachycardic during stable sleep (55.1 ± 6.7 vs. 26.9 ± 3 breath/min and 127.6 ± 8.7 vs. 97.6 ± 6.9 beats/min, respectively, p < 0.05 for both). They had shorter total sleep time (195 ± 49 vs. 373 ± 16 min, p < 0.05) with a low sleep efficiency of 65.6 ± 6%. None of the children had a pattern of CSR at any time during the studies while the adults with CHF had 40% prevalence of CSR. Conclusions: The complete absence of CSR in our sample of children with CHF compared to the 40% prevalence in the adults with CHF we studied, suggests that CSR may be an age-dependent phenomenon. Thus, we speculate that regardless of the exact mechanism which drives CSR, age is an over-riding factor. PMID:21423443
Bernatsky, S; Hudson, M; Suissa, S
2005-05-01
To assess the risk of hospitalization for congestive heart failure (CHF) associated with the use of disease-modifying anti-rheumatic drugs (DMARDs) and other medications used in RA. We used a case-control design nested within an administrative database cohort of patients with rheumatoid arthritis (RA) who were dispensed a DMARD between September 1998 and December 2001. Subjects identified with a prior history of CHF were excluded. For each hospitalized case of CHF identified during follow-up, 10 controls matched on age and time were randomly selected from the cohort. Conditional logistic regression was used to estimate the rate ratio (RR) of hospitalizations for CHF associated with the current use of specific drugs, adjusted for sex and co-morbidity. The cohort included 41 885 patients; 75% were women, with an average age at cohort entry of 51 yr. During follow-up, 520 hospitalizations for CHF occurred, for a rate of 10.1 per 1000 per year. The adjusted RR of CHF for current use of any DMARD was 0.7 (95% CI 0.6-0.9) relative to no current use. By DMARD category, there was evidence of a beneficial effect for both tumour necrosis factor-alpha antagonists (RR 0.5, 95% CI 0.2-0.9) and methotrexate monotherapy (RR 0.8, 95% CI 0.6-1.0). For non-DMARD medications, the rate of CHF was not clearly increased or decreased, except for COX-2 inhibitors. The data suggested an increased risk of CHF with rofecoxib (RR 1.3, 95% CI 1.0-3.1) and a decreased risk of CHF with celecoxib (RR 0.6, 95% CI 0.4, 1.0). The use of DMARDs was associated with a reduction in the risk of hospitalizations for CHF in this RA cohort. The increased risk with rofecoxib alongside a decreased risk with celecoxib suggests the absence of a class effect with respect to COX-II inhibitors for some types of cardiovascular morbidity.
Červenka, Luděk; Škaroupková, Petra; Kompanowska-Jezierska, Elzbieta; Sadowski, Janusz
2016-10-01
The role of hypertension and the renin-angiotensin system (RAS) in sex-related differences in the course of chronic kidney disease (CKD) and congestive heart failure (CHF) remain unclear, especially when the two diseases are combined. In male and female Ren-2 transgenic rats (TGR), a model of hypertension with activation of endogenous RAS, CKD was induced by 5/6 renal mass reduction (5/6 NX) and CHF was elicited by volume overload achieved by creation of an aorto-caval fistula (ACF). The primary aim of the study was to examine long-term CKD- and CHF-related mortality, especially in animals with CKD and CHF combined, with particular interest in the potential sex-related differences. The follow-up period was 23 weeks after the first intervention (5/6 NX). We found, first, that TGR did not exhibit sexual dimorphism in the course of 5/6 NX-induced CKD. Second, in contrast, TGR exhibited important sex-related differences in the course of ACF-induced CHF-related mortality: intact female TGR showed higher survival rate than male TGR. This situation is reversed in the course of combined 5/6 NX-induced CKD and ACF-induced CHF-related mortality: intact female TGR exhibited poorer survival than male TGR. Third, the survival rate in animals with combined 5/6 NX-induced CKD and ACF-induced CHF was significantly worsened as compared with rat groups that were exposed to 'single organ disease'. Collectively, our present results clearly show that CKD aggravates long-term mortality of animals with CHF. In addition, TGR exhibit remarkable sexual dimorphism with respect to CKD- and CHF-related mortality, especially in animals with combined CKD and CHF. © 2016 John Wiley & Sons Australia, Ltd.
So-Armah, Kaku A; Lim, Joseph K; Lo Re, Vincent; Tate, Janet P; Chang, Chung-Chou H; Butt, Adeel A; Gibert, Cynthia L; Rimland, David; Marconi, Vincent C; Goetz, Matthew B; Rodriguez-Barradas, Maria C; Budoff, Matthew J; Tindle, Hilary A; Samet, Jeffrey H; Justice, Amy C; Freiberg, Matthew S
2017-10-01
Liver fibrosis is common, particularly in individuals who are infected with human immunodeficiency virus (HIV). HIV-infected individuals have excess congestive heart failure (CHF) risk compared with uninfected people. It remains unknown whether liver fibrosis stage influences the CHF risk or if HIV or hepatitis C virus (HCV) infection modifies this association. Our objectives were to assess whether 1) stage of liver fibrosis is independently associated with incident CHF and 2) the association between stage of liver fibrosis and incident CHF is modified by HIV/HCV status. Participants alive on or after April 1, 2003, in the Veterans Aging Cohort Study were included. Those without prevalent cardiovascular disease were followed until their first CHF event, death, last follow-up date, or December 31, 2011. Liver fibrosis was measured using the fibrosis 4 index (FIB-4), which is calculated using age, aminotransferases, and platelets. Cox proportional hazards regression models were adjusted for cardiovascular disease risk factors. Among 96,373 participants over 6.9 years, 3844 incident CHF events occurred. FIB-4 between 1.45 and 3.25 (moderate fibrosis) and FIB-4 > 3.25 (advanced fibrosis/cirrhosis) were associated with CHF (hazard ratio [95% confidence interval], 1.17 [1.07-1.27] and 1.65 [1.43-1.92], respectively). The association of advanced fibrosis/cirrhosis and incident CHF persisted regardless of HIV/HCV status. Moderate and advanced liver fibrosis/cirrhosis are associated with an increased risk of CHF. The association for advanced fibrosis/cirrhosis persists even among participants without hepatitis C and/or HIV infection. Assessing liver health may be important for reducing the risk of future CHF events, particularly among HIV and hepatitis C infected people among whom cardiovascular disease risk is elevated and liver disease is common. (Hepatology 2017;66:1286-1295). © 2017 by the American Association for the Study of Liver Diseases.
Can home care for homebound patients with chronic heart failure reduce hospitalizations and costs?
Punchik, Boris; Komarov, Roman; Gavrikov, Dmitry; Semenov, Anna; Freud, Tamar; Kagan, Ella; Goldberg, Yury; Press, Yan
2017-01-01
Congestive heart failure (CHF), a common problem in adults, is associated with multiple hospitalizations, high mortality rates and high costs. To evaluate whether home care for homebound patients with CHF reduces healthcare service utilization and overall costs. A retrospective study of healthcare utilization among homebound patients who received home care for CHF from 2012-1015. The outcome measures were number of hospital admissions per month, total number of hospitalization days and days for CHF only, emergency room visits, and overall costs. A comparison was conducted between the 6-month period prior to entry into home care and the time in home care. Over the study period 196 patients were treated by home care for CHF with a mean age of 79.4±9.5 years. 113 (57.7%) were women. Compared to the six months prior to home care, there were statistically significant decreases in hospitalizations (46.3%), in the number of total in-hospital days (28.7%), in the number of in-hospital days for CHF (66.7%), in emergency room visits (47%), and in overall costs (23.9%). Home care for homebound adults with CHF can reduce healthcare utilization and healthcare costs.
Iskandar, Reinard; Liu, Shengchen; Xiang, Fei; Chen, Wen; Li, Liangpeng; Qin, Wei; Huang, Fuhua; Chen, Xin
2017-05-01
Pericardial fluid, as a biochemical indicator of heart status, directly indicates pathological alteration to the heart. The accumulation of pericardial fluid can be attributed to an underlying systemic or local inflammatory process. However, the pericardial fluid expression of cellular surface markers, as well as several cytokines in chronic heart failure (CHF), remain unclear. In order to evaluate these issues further the pericardial fluid expression of several cytokines and the surface expression of activity markers between CHF patients and non-heart failure (NHF) patients were analyzed. The pericardial fluid expression of cytokines was measured by immunofluorescence and biomarker of plasma N-terminal propeptide of B-type natriuretic peptide (NT-proBNP), while pericardial fluid levels of soluble glycoprotein 130 (sgp130) were analyzed by ELISA in 50 CHF and 24 NHF patients. In addition, the surface expression of activation markers for T-cells was measured by immunohistochemistry. Patients with CHF demonstrated increased levels of plasma NT-proBNP and pericardial fluid sgp130. Surface expression of cellular activation markers CD25 and Foxp3 in the pericardial fluid was increased in patients with CHF. Moreover, the pro- and anti-inflammatory cytokines interferon (IFN)-γ, interleukin (IL)-6 and IL-10 in patients with CHF also demonstrated an increased expression within its pericardial fluid. In addition, there was infiltration of inflammatory cells and enhanced expression of inflammatory cytokines in the pericardial fluid of patients with CHF, which may reflect T cell activation, suggesting that systemic inflammation is important in the progression of CHF. This evidence could indicate a possible novel target for future therapeutics and prevention of CHF.
AGXT2 rs37369 polymorphism predicts the renal function in patients with chronic heart failure.
Hu, Xiao-Lei; Zeng, Wen-Jing; Li, Mu-Peng; Yang, Yong-Long; Kuang, Da-Bin; Li, He; Zhang, Yan-Jiao; Jiang, Chun; Peng, Li-Ming; Qi, Hong; Zhang, Ke; Chen, Xiao-Ping
2017-12-30
Patients with chronic heart failure (CHF) are often accompanied with varying degrees of renal diseases. The purpose of this study was to identify rs37369 polymorphism of AGXT2 specific to the renal function of CHF patients. A total of 1012 southern Chinese participants, including 487 CHF patients without history of renal diseases and 525 healthy volunteers, were recruited for this study. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to determine the genotypes of AGXT2 rs37369 polymorphism. Levels of blood urea nitrogen (BUN) and serum creatinine (SCr) were detected to indicate the renal function of the participants. BUN level was significantly higher in CHF patients without history of renal diseases compared with healthy volunteers (p=0.000). And the similar result was also obtained for SCr (p=0.000). Besides, our results indicated that the level of BUN correlated significantly with SCr in both the CHF patients without renal diseases (r=0.4533, p<0.0001) and volunteers (r=0.2489, p<0.0001). Furthermore, we found that the AGXT2 rs37369 polymorphism could significantly affect the level of BUN in CHF patients without history of renal diseases (p=0.036, AA+AG vs GG). Patients with rs37369 GG genotype showed a significantly reduced level of BUN compared to those with the AA genotype (p=0.024), and the significant difference was still observed in the smokers of CHF patients without renal diseases (p=0.023). In conclusion, we found that CHF might induce the impairment of kidney and cause deterioration of renal function. AGXT2 rs37369 polymorphism might affect the renal function of CHF patients free from renal diseases, especially in patients with cigarette smoking. Copyright © 2017. Published by Elsevier B.V.
Ranasinghe, Isuru; Naoum, Chris; Aliprandi-Costa, Bernadette; Sindone, Andrew P; Steg, P Gabriel; Elliott, John; McGarity, Bruce; Lefkovits, Jeffrey; Brieger, David
2012-05-01
The outcome of patients with chronic heart failure (CHF) following an ischaemic event is poorly understood. We evaluated the management and outcomes of CHF patients presenting with an acute coronary syndrome (ACS) and explored changes in outcomes over time. A total of 5556 patients enrolled in the Australia-New Zealand population of the Global Registry of Acute Coronary Events (GRACE) between 1999 and 2007 were included. Patients with CHF (n = 609) were compared with those without CHF (n = 4947). Patients with CHF were on average 10 years older, were more likely to be female, had more co-morbidities and cardiac risk factors, and were more likely to have a prior history of angina, myocardial infarction, and revascularization by coronary artery bypass graft (CABG) when compared with those without CHF. CHF was associated with a substantial increase in in-hospital renal failure [odds ratio (OR) 1.76, 95% confidence interval (CI) 1.15-2.71], readmission post-discharge (OR 1.47, 95% CI 1.17-1.90), and 6-month mortality (OR 2.25, 95% CI 1.55-3.27). Over the 9 year study period, in-hospital and 6 month mortality in those with CHF declined by absolute rates of 7.5% and 14%, respectively. This was temporally associated with an increase in prescription of thienopyridines, beta-blockers, statins, and angiotensin II receptor blockers, increased rates of coronary angiography, and 31.8% absolute increase in referral rates for cardiac rehabilitation. Acute coronary syndrome patients with pre-existing CHF are a very high risk group and carry a disproportionate mortality burden. Encouragingly, there was a marked temporal improvement in outcomes over a 9 year period with an increase in evidence-based treatments and secondary preventative measures.
Choi, Jung Yoon; Cho, Eun Young; Choi, Yoon Ji; Lee, Jeong Hyeon; Jung, Seung Pil; Cho, Kyu Ran; Kim, Chul Yong; Kim, Yeul Hong; Park, Kyong Hwa
2018-05-08
We aimed to analyze the incidence, time to occurrence, and congestive heart failure (CHF) risk factors for early breast cancer patients treated with anthracycline (AC)-based chemotherapy and/or trastuzumab (T) therapy in Korea. We included female patients > 19 years old from the Health Insurance Review and Assessment Service database who had no prior CHF history and had been diagnosed with early breast cancer between January 2007 and October 2016. We included 83,544 patients in our analysis. In terms of crude incidence for CHF, AC followed by T showed the highest incidence (6.3%). However, 3.1 and 4.2% of the patients had CHF due to AC-based chemotherapy and non-AC followed by T, respectively. The median times to occurrence of CHF were different according to adjuvant treatments, approximately 2 years (701.0 days) in the AC-based chemotherapy group vs 1 year (377.5 days) AC followed by T group. T therapy was associated with earlier development of CHF irrespective of previous chemotherapy, but late risk of CHF 1.2 years after T therapy rapidly decreased in both chemotherapy groups. Multivariate Cox regression analysis revealed that the adjusted hazard ratio for CHF was increased in the group of older patients (≥ 65 years old) who underwent AC followed by T therapy, with Charlson comorbidity index scores of ≥ 2. Our study showed that neo-/adjuvant chemotherapy using T irrespective of previous chemotherapy (AC or non-AC) was associated with significantly increased risk of CHF compared with AC-based chemotherapy in Korean patients with early breast cancer.
A Remote Patient Monitoring System for Congestive Heart Failure
Suh, Myung-kyung; Chen, Chien-An; Woodbridge, Jonathan; Tu, Michael Kai; Kim, Jung In; Nahapetian, Ani; Evangelista, Lorraine S.; Sarrafzadeh, Majid
2011-01-01
Congestive heart failure (CHF) is a leading cause of death in the United States affecting approximately 670,000 individuals. Due to the prevalence of CHF related issues, it is prudent to seek out methodologies that would facilitate the prevention, monitoring, and treatment of heart disease on a daily basis. This paper describes WANDA (Weight and Activity with Blood Pressure Monitoring System); a study that leverages sensor technologies and wireless communications to monitor the health related measurements of patients with CHF. The WANDA system is a three-tier architecture consisting of sensors, web servers, and back-end databases. The system was developed in conjunction with the UCLA School of Nursing and the UCLA Wireless Health Institute to enable early detection of key clinical symptoms indicative of CHF-related decompensation. This study shows that CHF patients monitored by WANDA are less likely to have readings fall outside a healthy range. In addition, WANDA provides a useful feedback system for regulating readings of CHF patients. PMID:21611788
Liu, Hui; Tian, Yaohua; Song, Jing; Cao, Yaying; Xiang, Xiao; Huang, Chao; Li, Man; Hu, Yonghua
2018-03-01
There is growing interest in the association between ambient air pollution and congestive heart failure (CHF), but research data from developing countries are very limited. The primary aim of this study was to examine the association between short-term exposure to air pollution and hospital admission for CHF in China. A time-stratified case-crossover study was conducted between 2014 and 2015 in 26 large Chinese cities among 105,501 CHF hospitalizations. Conditional logistic regression models were applied to estimate the percentage changes in CHF admissions in relation to per interquartile range increases in air pollutant concentrations. Air pollution was positively associated with CHF hospitalizations. An interquartile range increase in fine particulate, particulate matter less than 10 µm in aerodynamic diameter, sulfur dioxide, nitrogen dioxide, carbon monoxide, and ozone concentrations on the current day corresponded to 1.2% (95% confidence interval [CI] 0.5%, 1.8%), 1.3% (95% CI 0.5%, 2.0%), 1.0% (95% CI 0.2%, 1.7%), 1.6% (95% CI 0.6%, 2.5%), 1.2% (95% CI 0.5%, 1.9%), and 0.4% (95% CI -0.9%, 1.7%) increases in CHF admissions, respectively. In conclusion, our findings contribute to the limited scientific literature concerning the effects of air pollution on CHF risk for high-exposure settings typical in developing countries, which may have significant public health implications for prevention of CHF in China. Copyright © 2017 Elsevier Inc. All rights reserved.
Nutritional and Anti-Inflammatory Interventions in Chronic Heart Failure
Kalantar-Zadeh, Kamyar; Anker, Stefan D; Horwich, Tamara B; Fonarow, Gregg C
2017-01-01
Summary Five million individuals with chronic heart failure (CHF) in the United States have poor clinical outcomes including high death rates. Observational studies have indicated a reverse epidemiology of traditional cardiovascular risk factors in CHF; in contrast to trends seen in the general population, obesity and hypercholesterolemia are associated with improved survival. The temporal discordance between the overnutrition (long-term killer) and undernutrition (short-term killer) not only can explain some of the observed paradoxes but also may indicate a role for malnutrition, inflammation and oxidative stress that result in cachexia contributing to poor survival in CHF. Diminished appetite or anorexia may be both a cause and a consequence of this so-called malnutrition-inflammation-cachexia (MIC) or wasting syndrome in CHF. Neurohumoral activation, insulin resistance, cytokine activation and survival selection resultant genetic polymorphisms may also contribute to the prominent inflammatory and oxidative characteristics of this population. In CHF patients with wasting, nutritional strategies may be a promising therapeutic approach in CHF, especially if the provision of additional protein and energy also includes nutrients with anti-inflammatory and anti-oxidant properties. Regardless of the etiology of anorexia, appetite stimulating agents especially with anti-inflammatory properties such as megesterol acetate or pentoxyphylline may be appropriate adjuncts to dietary supplementation. Understanding the factors that modulate the MIC and wasting and their associations with clinical outcomes in CHF may lead to the development of nutritional strategies that alter the pathophysiology of CHF and improve outcomes PMID:18514634
Cui, Jian; Boehmer, John P; Blaha, Cheryl; Lucking, Robert; Kunselman, Allen R; Sinoway, Lawrence I
2013-03-01
Previous studies show that the rise in skin blood flow and cutaneous vascular conductance during heat stress is substantially attenuated in chronic heart failure (CHF) patients. The mechanisms responsible for this finding are not clear. In particular, little is known regarding the responses of skin sympathetic nerve activity (SSNA) that control the skin blood flow during heat stress in CHF patients. We examined the effects of a modest heat stress to test the hypothesis that SSNA responses could be attenuated in CHF. We assessed SSNA (microneurography) from the peroneal nerve and skin blood flow (forearm laser Doppler) in 9 patients with stable class II-III CHF and in matched healthy subjects during passive whole-body heating with a water-perfused suit. Whole-body heating induced similar increases in internal temperature (≈0.6 °C) in both groups. Whole-body heat stress evoked similar SSNA activation in CHF patients (Δ891±110 U/min) and the control subjects (Δ787±84 U/min; P=0.66), whereas the elevation in forearm cutaneous vascular conductance in patients with CHF was significantly lower than that in healthy control subjects (Δ131±29% vs. Δ623±131%; P=0.001). The present data show that SSNA activation during a modest whole-body heat stress is not attenuated in CHF. Thus, the attenuated skin vasodilator response in CHF patients is not attributable to a reduction in total activity of sympathetic outflow to skin.
Mulder, Paul; Mellin, Virginie; Favre, Julie; Vercauteren, Magali; Remy-Jouet, Isabelle; Monteil, Christelle; Richard, Vincent; Renet, Sylvanie; Henry, Jean Paul; Jeng, Arco Y; Webb, Randy L; Thuillez, Christian
2008-09-01
Inhibition of aldosterone synthase, the key enzyme in aldosterone formation, could be an alternative strategy for mineralocorticoid-receptor antagonists in congestive heart failure (CHF), but its effect in CHF is unknown. We compared, in rats with CHF, the effects of a 7 day and a 12 week treatment with the aldosterone synthase inhibitor FAD286 (4 mg kg(-1) day(-1)) with those induced by spironolactone (80 mg kg(-1) day(-1)). FAD286/spironolactone increased cardiac output without modifying arterial pressure. Long-term FAD286 and spironolactone reduced left ventricular (LV) end-diastolic pressure, LV relaxation constant, and LV dilatation, and these effects were more marked with FAD286, whereas both drugs reduced LV hypertrophy and collagen accumulation to the same extent. Long-term FAD286/spironolactone prevented CHF-related enhancement in LV ACE and reduction in LV ACE-2, but only FAD286 prevented the reduction in LV AT(2) receptors. FAD286, but not long-term spironolactone, reduced the CHF-related enhancements in LV reactive oxygen species, reduced-oxidized glutathione ratio, and aortic nicotinamide adenine dinucleotide phosphate oxidase activity. FAD286 normalized the CHF-induced impairment of endothelium-dependent vasodilatation. In experimental CHF, FAD286 and spironolactone improve LV haemodynamics, remodelling, and function, but only FAD286 persistently normalizes LV 'redox status'. These results suggest that aldosterone synthase inhibition is a potential therapeutic strategy for the treatment of CHF.
Can home care for homebound patients with chronic heart failure reduce hospitalizations and costs?
Punchik, Boris; Komarov, Roman; Gavrikov, Dmitry; Semenov, Anna; Freud, Tamar; Kagan, Ella; Goldberg, Yury
2017-01-01
Background Congestive heart failure (CHF), a common problem in adults, is associated with multiple hospitalizations, high mortality rates and high costs. Purpose To evaluate whether home care for homebound patients with CHF reduces healthcare service utilization and overall costs. Methods A retrospective study of healthcare utilization among homebound patients who received home care for CHF from 2012–1015. The outcome measures were number of hospital admissions per month, total number of hospitalization days and days for CHF only, emergency room visits, and overall costs. A comparison was conducted between the 6-month period prior to entry into home care and the time in home care. Results Over the study period 196 patients were treated by home care for CHF with a mean age of 79.4±9.5 years. 113 (57.7%) were women. Compared to the six months prior to home care, there were statistically significant decreases in hospitalizations (46.3%), in the number of total in-hospital days (28.7%), in the number of in-hospital days for CHF (66.7%), in emergency room visits (47%), and in overall costs (23.9%). Conclusion Home care for homebound adults with CHF can reduce healthcare utilization and healthcare costs. PMID:28753675
Verma, Arun K.; Banerjee, Rituparna; Sharma, B. D.
2012-01-01
While attempting to develop low salt, low fat and high fibre chicken nuggets, the effect of partial (40%) common salt substitution and incorporation of chickpea hull flour (CHF) at three different levels viz., 5, 7.5 and 10% (Treatments) in pre-standardized low fat chicken nuggets (Control) were observed. Common salt replacement with salt substitute blend led to a significant decrease in pH, emulsion stability, moisture, ash, hardness, cohesiveness, gumminess and chewiness values while incorporation of CHF in low salt, low fat products resulted in decreased emulsion stability, cooking yield, moisture, protein, ash, color values, however dietary fibre and textural properties were increased (p<0.01). Lipid profile revealed a decrease in total cholesterol and glycolipid contents with the incorporation of CHF (p<0.01). All the sensory attributes except appearance and flavor, remained unaffected with salt replacement, while addition of CHF resulted in lower sensory scores (p<0.01). Among low salt, low fat chicken nuggets with CHF, incorporation CHF at 5% level was found optimum having sensory ratings close to very good. Thus most acceptable low salt, low fat and high fibre chicken nuggets could be developed by a salt replacement blend and addition of 5% CHF. PMID:25049565
Vyshedskiy, Andrey; Ishikawa, Sadamu; Murphy, Raymond L H
2011-06-01
To determine the variability of crackle pitch and crackle rate during a single automated-auscultation session with a computerized 16-channel lung-sound analyzer. Forty-nine patients with pneumonia, 52 with congestive heart failure (CHF), and 18 with interstitial pulmonary fibrosis (IPF) performed breathing maneuvers in the following sequence: normal breathing, deep breathing, cough several times; deep breathing, vital-capacity maneuver, and deep breathing. From the auscultation recordings we measured the crackle pitch and crackle rate. Crackle pitch variability, expressed as a percentage of the average crackle pitch, was small in all patients and in all maneuvers: pneumonia 11%, CHF 11%, pulmonary fibrosis 7%. Crackle rate variability was also small: pneumonia 31%, CHF 32%, IPF 24%. Compared to the first deep-breathing maneuver (100%), the average crackle pitch did not significantly change following coughing (pneumonia 100%, CHF 103%, IPF 100%), the vital-capacity maneuver (pneumonia 100%, CHF 92%, IPF 104%), or during quiet breathing (pneumonia 97%, CHF 100%, IPF 104%). Similarly, the average crackle rate did not change significantly following coughing (pneumonia 105%, CHF 110%, IPF 90%) or the vital-capacity maneuver (pneumonia 102%, CHF 101%, IPF 99%). However, during normal breathing the crackle rate was significantly lower in the patients with pneumonia (74%, P < .001) and significantly higher in the patients with IPF (147%, P < .05) than it was during deep breathing. In patients with CHF the average crackle rate during normal breathing was not significantly different from that during the first deep-breathing maneuver (108%). Crackle pitch and rate were surprisingly stable in all 3 conditions. Neither crackle pitch nor crackle rate changed significantly from breath to breath or from one deep-breathing maneuver to another, even when the maneuvers were separated by cough or the vital-capacity maneuver. The observation that crackle rate is a reproducible measurement during one automated-auscultation session suggests that crackle rate can be used to follow the course of cardiopulmonary illnesses such as pneumonia, IPF, and CHF.
Zhu, Yujie; Hanafy, Mohamed A; Killingsworth, Cheryl R; Walcott, Gregory P; Young, Martin E; Pogwizd, Steven M
2014-01-01
Patients with chronic heart failure (CHF) exhibit a morning surge in ventricular arrhythmias, but the underlying cause remains unknown. The aim of this study was to determine if heart rate dynamics, autonomic input (assessed by heart rate variability (HRV)) and nonlinear dynamics as well as their abnormal time-of-day-dependent oscillations in a newly developed arrhythmogenic canine heart failure model are associated with a morning surge in ventricular arrhythmias. CHF was induced in dogs by aortic insufficiency & aortic constriction, and assessed by echocardiography. Holter monitoring was performed to study time-of-day-dependent variation in ventricular arrhythmias (PVCs, VT), traditional HRV measures, and nonlinear dynamics (including detrended fluctuations analysis α1 and α2 (DFAα1 & DFAα2), correlation dimension (CD), and Shannon entropy (SE)) at baseline, as well as 240 days (240 d) and 720 days (720 d) following CHF induction. LV fractional shortening was decreased at both 240 d and 720 d. Both PVCs and VT increased with CHF duration and showed a morning rise (2.5-fold & 1.8-fold increase at 6 AM-noon vs midnight-6 AM) during CHF. The morning rise in HR at baseline was significantly attenuated by 52% with development of CHF (at both 240 d & 720 d). Morning rise in the ratio of low frequency to high frequency (LF/HF) HRV at baseline was markedly attenuated with CHF. DFAα1, DFAα2, CD and SE all decreased with CHF by 31, 17, 34 and 7%, respectively. Time-of-day-dependent variations in LF/HF, CD, DFA α1 and SE, observed at baseline, were lost during CHF. Thus in this new arrhythmogenic canine CHF model, attenuated morning HR rise, blunted autonomic oscillation, decreased cardiac chaos and complexity of heart rate, as well as aberrant time-of-day-dependent variations in many of these parameters were associated with a morning surge of ventricular arrhythmias.
Zhu, Yujie; Hanafy, Mohamed A.; Killingsworth, Cheryl R.; Walcott, Gregory P.; Young, Martin E.; Pogwizd, Steven M.
2014-01-01
Patients with chronic heart failure (CHF) exhibit a morning surge in ventricular arrhythmias, but the underlying cause remains unknown. The aim of this study was to determine if heart rate dynamics, autonomic input (assessed by heart rate variability (HRV)) and nonlinear dynamics as well as their abnormal time-of-day-dependent oscillations in a newly developed arrhythmogenic canine heart failure model are associated with a morning surge in ventricular arrhythmias. CHF was induced in dogs by aortic insufficiency & aortic constriction, and assessed by echocardiography. Holter monitoring was performed to study time-of-day-dependent variation in ventricular arrhythmias (PVCs, VT), traditional HRV measures, and nonlinear dynamics (including detrended fluctuations analysis α1 and α2 (DFAα1 & DFAα2), correlation dimension (CD), and Shannon entropy (SE)) at baseline, as well as 240 days (240d) and 720 days (720d) following CHF induction. LV fractional shortening was decreased at both 240d and 720d. Both PVCs and VT increased with CHF duration and showed a morning rise (2.5-fold & 1.8-fold increase at 6 AM-noon vs midnight-6 AM) during CHF. The morning rise in HR at baseline was significantly attenuated by 52% with development of CHF (at both 240d & 720d). Morning rise in the ratio of low frequency to high frequency (LF/HF) HRV at baseline was markedly attenuated with CHF. DFAα1, DFAα2, CD and SE all decreased with CHF by 31, 17, 34 and 7%, respectively. Time-of-day-dependent variations in LF/HF, CD, DFA α1 and SE, observed at baseline, were lost during CHF. Thus in this new arrhythmogenic canine CHF model, attenuated morning HR rise, blunted autonomic oscillation, decreased cardiac chaos and complexity of heart rate, as well as aberrant time-of-day-dependent variations in many of these parameters were associated with a morning surge of ventricular arrhythmias. PMID:25140699
Speicher, Paul J; Ganapathi, Asvin M; Englum, Brian R; Vaslef, Steven N
2014-08-01
Over the past 2 decades, laparoscopy has been established as a superior technique in many general surgery procedures. Few studies, however, have examined the impact of the use of a laparoscopic approach in patients with symptomatic congestive heart failure (CHF). Because pneumoperitoneum has known effects on cardiopulmonary physiology, patients with CHF may be at increased risk. This study examines current trends in approaches to patients with CHF and effects on perioperative outcomes. The 2005-2011 National Surgical Quality Improvement Program Participant User File was used to identify patients who underwent the following general surgery procedures: Appendectomy, segmental colectomy, small bowel resection, ventral hernia repair, and splenectomy. Included for analysis were those with newly diagnosed CHF or chronic CHF with new signs or symptoms. Trends of use of laparoscopy were assessed across procedure types. The primary endpoint was 30-day mortality. The independent effect of laparoscopy in CHF was estimated with a multiple logistic regression model. A total of 265,198 patients were included for analysis, of whom 2,219 were identified as having new or recently worsened CHF. Of these patients, there were 1,300 (58.6%) colectomies, 486 (21.9%) small bowel resections, 216 (9.7%) ventral hernia repairs, 141 (6.4%) appendectomies, and 76 (3.4%) splenectomies. Laparoscopy was used less frequently in patients with CHF compared with their non-CHF counterparts, particularly for nonelective procedures. Baseline characteristics were similar for laparoscopy versus open procedures with the notable exception of urgent/emergent case status (36.4% vs 71.3%; P < .001). After multivariable adjustment, laparoscopy seemed to have a protective effect against mortality (adjusted odds ratio, 0.45; P = .04), but no differences in other secondary endpoints. For patients with CHF, an open operative approach seems to be utilized more frequently in general surgery procedures, particularly in urgent/emergent cases. Despite these patterns and apparent preferences, laparoscopy seems to offer a safe alternative in appropriately selected patients. Because morbidity and mortality were considerable regardless of approach, further understanding of appropriate management in this population is necessary. Copyright © 2014 Mosby, Inc. All rights reserved.
Speicher, Paul J.; Ganapathi, Asvin M.; Englum, Brian R.; Vaslef, Steven N.
2015-01-01
Background Over the past 2 decades, laparoscopy has been established as a superior technique in many general surgery procedures. Few studies, however, have examined the impact of the use of a laparoscopic approach in patients with symptomatic congestive heart failure (CHF). Because pneumoperitoneum has known effects on cardiopulmonary physiology, patients with CHF may be at increased risk. This study examines current trends in approaches to patients with CHF and effects on perioperative outcomes. Methods The 2005–2011 National Surgical Quality Improvement Program Participant User File was used to identify patients who underwent the following general surgery procedures: Appendectomy, segmental colectomy, small bowel resection, ventral hernia repair, and splenectomy. Included for analysis were those with newly diagnosed CHF or chronic CHF with new signs or symptoms. Trends of use of laparoscopy were assessed across procedure types. The primary endpoint was 30-day mortality. The independent effect of laparoscopy in CHF was estimated with a multiple logistic regression model. Results A total of 265,198 patients were included for analysis, of whom 2,219 were identified as having new or recently worsened CHF. Of these patients, there were 1,300 (58.6%) colectomies, 486 (21.9%) small bowel resections, 216 (9.7%) ventral hernia repairs, 141 (6.4%) appendectomies, and 76 (3.4%) splenectomies. Laparoscopy was used less frequently in patients with CHF compared with their non-CHF counterparts, particularly for nonelective procedures. Baseline characteristics were similar for laparoscopy versus open procedures with the notable exception of urgent/emergent case status (36.4% vs 71.3%; P < .001). After multivariable adjustment, laparoscopy seemed to have a protective effect against mortality (adjusted odds ratio, 0.45; P = .04), but no differences in other secondary endpoints. Conclusion For patients with CHF, an open operative approach seems to be utilized more frequently in general surgery procedures, particularly in urgent/emergent cases. Despite these patterns and apparent preferences, laparoscopy seems to offer a safe alternative in appropriately selected patients. Because morbidity and mortality were considerable regardless of approach, further understanding of appropriate management in this population is necessary. PMID:24947641
Tsuji, Shuhei; Koyama, Satoshi; Taniguchi, Ryoji; Fujiwara, Takako; Fujiwara, Hisayoshi; Sato, Yukihito
2018-06-06
Loss of skeletal muscle mass and low nutritional status are major complications of severe chronic heart failure (CHF) and have been associated with poor prognosis. This study aimed to identify the nutritional status of outpatients with CHF based on their body composition, such as skeletal muscle index (SMI) and serum amino acid concentration. We compared the body composition data and results of blood samples, including the serum amino acid concentration, of patients with CHF and those of controls. No significant difference was found in total amino acid concentration between 105 patients with CHF (62% men, mean age: 71.0±11.0 years) and 106 controls (67% men, mean age: 69.1±9.4 years) (CHF: 3459.1±504.9nmol/ml, control: 3575.8±513.1nmol/ml; p=0.072). However, the concentration of essential amino acids (EAA) (CHF: 949.5±197.9nmol/ml, control: 1034.1±207.3nmol/ml; p=0.002) and branched-chain amino acid (BCAA) (CHF: 449.3±114.3nmol/ml, control: 503.9±118.2nmol/ml; p<0.001) and Fischer's ratio (CHF: 2.86±0.62, control: 3.17±0.50; p<0.001) were significantly lower in patients with CHF. Integrated analysis of these data revealed that SMI was negatively correlated with age [correlation coefficient (R), -0.313; 95% confidence interval (CI), -0.514 to -0.079; p=0.010], but positively correlated with EAA concentration (R, 0.256; 95% CI, 0.017-0.467; p=0.037), BCAA concentration (R, 0.362; 95% CI, 0.134-0.554; p=0.003), and Fischer's ratio (R, 0.573; 95% CI, 0.386-0.715; p<0.001). Serum concentrations of EAA and BCAA and Fischer's ratio were lower in patients with CHF than in controls, while SMI correlated with EAA, BCAA, and Fischer's ratio. Copyright © 2018 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.
Liao, Huai; Na, Moon Jun; Dikensoy, Oner; Lane, Kirk B; Randal, Barnette; Light, Richard W
2008-01-01
The diagnosis of the cause of pleural effusions caused by cardiovascular diseases such as congestive heart failure (CHF) and acute pulmonary embolism is sometimes difficult. The purpose of the present study was to evaluate the utility of pleural fluid levels of N-terminal pro-brain natriuretic peptide (NT-proBNP) in differentiating pleural effusions due to CHF, pulmonary embolism and post-coronary artery bypass graft (CABG) surgery. The levels of pleural fluid NT-proBNP were measured by ELISA in a total of 40 patients: 10 with CHF, 10 with pulmonary embolism, 10 post-CABG and 10 with carcinoma. The median level of NT-proBNP in the pleural fluid of patients with CHF was 5390 pg/mL (25th to 75th percentiles, 4566 to 8158 pg/mL), which was significantly higher than that in patients with post-CABG effusions (424 pg/mL, 352 to 873), with pulmonary embolism (311 pg/mL, 212 to 1159), or with carcinoma (302 pg/mL, 208 to 626) (P < 0.001, CHF group vs all other groups). In receiver-operating curve analysis, an NT-proBNP level of >or=2220 pg/mL demonstrated a sensitivity of 100% and a specificity of 96.7% for the identification of CHF. Measurement of the NT-proBNP level in pleural fluid is accurate in diagnosing the etiology of the effusion as CHF. Pleural fluid levels above 2220 pg/mL are essentially diagnostic that the pleural effusion is due to CHF.
Mehra, Tarun; Koljonen, Virve; Seifert, Burkhardt; Volbracht, Jörk; Giovanoli, Pietro; Plock, Jan; Moos, Rudolf Maria
2015-01-01
Reimbursement systems have difficulties depicting the actual cost of burn treatment, leaving care providers with a significant financial burden. Our aim was to establish a simple and accurate reimbursement model compatible with prospective payment systems. A total of 370 966 electronic medical records of patients discharged in 2012 to 2013 from Swiss university hospitals were reviewed. A total of 828 cases of burns including 109 cases of severe burns were retained. Costs, revenues and earnings for severe and nonsevere burns were analysed and a linear regression model predicting total inpatient treatment costs was established. The median total costs per case for severe burns was tenfold higher than for nonsevere burns (179 949 CHF [167 353 EUR] vs 11 312 CHF [10 520 EUR], interquartile ranges 96 782-328 618 CHF vs 4 874-27 783 CHF, p <0.001). The median of earnings per case for nonsevere burns was 588 CHF (547 EUR) (interquartile range -6 720 - 5 354 CHF) whereas severe burns incurred a large financial loss to care providers, with median earnings of -33 178 CHF (30 856 EUR) (interquartile range -95 533 - 23 662 CHF). Differences were highly significant (p <0.001). Our linear regression model predicting total costs per case with length of stay (LOS) as independent variable had an adjusted R2 of 0.67 (p <0.001 for LOS). Severe burns are systematically underfunded within the Swiss reimbursement system. Flat-rate DRG-based refunds poorly reflect the actual treatment costs. In conclusion, we suggest a reimbursement model based on a per diem rate for treatment of severe burns.
Increasing Healthcare Burden of Chronic Liver Disease Compared to Other Chronic Diseases, 2004-2013.
Asrani, Sumeet K; Kouznetsova, Maria; Ogola, Gerald; Taylor, Thomas; Masica, Andrew; Pope, Brandon; Trotter, James; Kamath, Patrick; Kanwal, Fasiha
2018-05-23
Chronic liver disease (CLD) is a common and expensive condition, and studies of CLD-related hospitalizations have underestimated the true burden of disease. We analyzed data from a large diverse healthcare system to compare time trends in CLD-related hospitalizations with those of congestive heart failure (CHF) or chronic obstructive pulmonary disease (COPD). We collected data from a large healthcare system in Texas on hospitalizations related to CLD (n=27,783), CHF (n=60,415), and COPD (n=34,199) from January 1, 2004 through December 31, 2013. We calculated annual hospitalization rates (per 100,000) and compared hospital course, inpatient mortality, ancillary services and re-admissions. Compared to patients with CHF (median age, 71 years) or COPD (median age 69 years), patients with CLD were significantly younger (median age 57 years; P<.01 vs CHF and COPD). Higher proportions of patients with CLD were uninsured (11.7% vs 5.4% for CHF and 5.4% for COPD; P<.01) and Hispanic (17% for CLD vs 9.3% for CHF and 5.0% for COPD; P<.01). A lower proportion of patients with CLD had Medicare (41.5% vs 68.6% with CHF and 70.1% with COPD; P<0.01). From 2004 through 2013, the rate of CLD-related hospitalization increased by 92% (from 1295/100,000 to 2490/100,000), compared to 6.7% for CHF (from 3843/100,000 to 4103/100,000) and 48.8% for COPD (from 1775/100,000 to 2642/100,000). During this time period, CLD-related hospitalizations covered by Medicare increased from 31.8% to 41.5%, whereas hospitalizations covered by Medicare did not change for CHF (remained at 70%) or COPD (remained at 70%). Patients with CLD had longer hospital stays (7.3 days vs 6.2 days for CHF or 5.9 days for COPD; P<.01). A higher proportion of patients with CLD died or were discharged to hospice (14.2% vs 11.5% of patients with CHF and 9.3% of patients with COPD P<.01), and a smaller proportion had access to post-acute care (13.2% vs 23.2% of patients with CHF and 27.4% of patients with COPD; P<.01). A higher proportion of patients with CLD were readmitted to the hospital within 30 days (25% vs 21.9% of patients with CHF and 20.6% with COPD; P<.01). Patients with chronic liver disease, compared to selected other chronic diseases, had increasing rates of hospitalization, longer hospital stays, more readmissions, and, despite these adverse outcomes, less access to post-acute care. Disease management models for chronic liver disease are greatly needed to manage the anticipated increase in hospitalizations for CLD. Copyright © 2018 AGA Institute. Published by Elsevier Inc. All rights reserved.
Heart Failure and Exercise: A Narrative Review of the Role of Self-Efficacy.
Ha, Francis J; Hare, David L; Cameron, James D; Toukhsati, Samia R
2018-01-01
Chronic heart failure (CHF) is a common, debilitating condition associated with significant health and economic burden. CHF management is multidisciplinary, however, achieving better health relies on a collaborative effort and patient engagement in self-care. Despite the importance of self-care in CHF, many patients have poor adherence to their medical and lifestyle regimens, in particular with regards to engaging in physical exercise. The patient's confidence in their ability, otherwise known as self-efficacy, is an important determinant of CHF health outcomes, most likely due to its effect on the uptake of CHF self-care activities especially exercise initiation and maintenance. Self-efficacy is responsive to experience such as exercise training, however the critical components of exercise interventions to improve self-efficacy have yet to be determined. This narrative review provides an overview of the role of self-efficacy in exercise adherence in CHF. Copyright © 2017 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.
GPCR-autoantibodies in chronic heart failure.
Boivin-Jahns, Valerie; Jahns, Roland
2018-06-01
Chronic heart failure (CHF) is a syndrome characterized by shortness of breath, fluid retention, and a progressive reduction in cardiac function. More than 60% of the cases are ischemic in origin (i.e., due to myo-cardial infarction) and about 30% are caused by non-ischemic myocardial damage (i.e., due to genetic or non-genetic causes like myocardial inflammation). Because of alterations in both cellular and humoral immunity patients with non-ischemic CHF often develop abnormal or misled immune responses, including cross-reacting antibodies and/or autoantibodies to various cardiac anti-gens. Non-ischemic myo-cardial damage was found to progress to CHF particularly, when associated (a) with the generation of autoantibodies directed against distinct myocyte membrane proteins critically involved in cardiac function - like G-protein coup-led membrane receptors (GPCRs), or (b) with virus persistence in the myocardium. This article will review current knowledge on the pathophysiological relevance of GPCR-autoreactivity in CHF by giving an overview on the so far available evidence from pre-clinical, clinical and epidemiological studies on the CHF-inducing potential of GPCR-autoantibodies and thereon based novel therapeutic approaches in GPCR autoantibody-associated CHF.
Treating anemia in heart failure patients: a review of erythropoiesis-stimulating agents.
Geisler, Benjamin P
2010-08-01
Prevalence of chronic heart failure (CHF) is increasing, and despite improvements in the past decade the prognosis in terms of mortality and health-related quality of life remains poor. Anemia is often found concomitantly in CHF patients. Erythropoiesis-stimulating agents (ESAs) are a new treatment option for these anemic CHF patients, promising to decrease mortality and hospitalizations, and increase health-related quality of life. CHF epidemiology is briefly discussed. Currently available clinical efficacy and safety data are critically appraised. Health care utilization by CHF patients, particularly hospitalizations, are reviewed in order predict cost-effectiveness of ESAs. The efficacy for the most pertinent endpoints has not been proven by a pivotal trial or a meta-analysis free of bias, and there might be increased cardiovascular events and cancer incidence rates above a currently unknown target value or with multiple doses. However, subgroups should be identified in which ESAs might prove to be more efficacious and as safe as usual care and either cost-saving or cost-effective. Nevertheless, depending on the subgroup, the budget effect for payors might be dramatic due to the large number of CHF patients.
Modeling and forecasting foreign exchange daily closing prices with normal inverse Gaussian
NASA Astrophysics Data System (ADS)
Teneng, Dean
2013-09-01
We fit the normal inverse Gaussian(NIG) distribution to foreign exchange closing prices using the open software package R and select best models by Käärik and Umbleja (2011) proposed strategy. We observe that daily closing prices (12/04/2008 - 07/08/2012) of CHF/JPY, AUD/JPY, GBP/JPY, NZD/USD, QAR/CHF, QAR/EUR, SAR/CHF, SAR/EUR, TND/CHF and TND/EUR are excellent fits while EGP/EUR and EUR/GBP are good fits with a Kolmogorov-Smirnov test p-value of 0.062 and 0.08 respectively. It was impossible to estimate normal inverse Gaussian parameters (by maximum likelihood; computational problem) for JPY/CHF but CHF/JPY was an excellent fit. Thus, while the stochastic properties of an exchange rate can be completely modeled with a probability distribution in one direction, it may be impossible the other way around. We also demonstrate that foreign exchange closing prices can be forecasted with the normal inverse Gaussian (NIG) Lévy process, both in cases where the daily closing prices can and cannot be modeled by NIG distribution.
Left lateral decubitus position on patients with atrial fibrillation and congestive heart failure
NASA Astrophysics Data System (ADS)
Varadan, Vijay K.; Kumar, Prashanth S.; Ramasamy, Mouli
2017-04-01
Congestive Heart Failure (CHF) is a cardiovascular disease that affects about 5.7 million people in the US. The most prevalent comorbidity to CHF is Atrial Fibrillation (AF). These two pathologies present in a mutually worsening manner in that patients diagnosed with CHF are more likely to develop AF and patients who are diagnosed with AF are more likely to develop CHF. The underlying pathophysiological mechanisms have been studied for several years and the most recent efforts are in the cellular and molecular basis. In this paper, we focus on manifestation of CHF and AF symptoms as influenced by the posture assumed by a patient. We consider three postures - Left lateral decubitus, right lateral decubitus and supine. We review the clinical evidence gathered thus far relating enhanced sympathetic activity to the left lateral decubitus and supine positions with equivalent evidence on the enhanced vagal activity when the right lateral decubitus posture is assumed. We conclude with a compilation of all the hypotheses on the mechanism by which the right lateral decubitus posture alleviates the symptoms of CHF and AF, and future avenues for investigation.
Hartman, Matthew E; Liu, Yonggang; Zhu, Wei-Zhong; Chien, Wei-Ming; Weldy, Chad S; Fishman, Glenn I; Laflamme, Michael A; Chin, Michael T
2014-07-01
CHF1/Hey2 is a Notch-responsive basic helix-loop-helix transcription factor involved in cardiac development. Common variants in Hey2 are associated with Brugada syndrome. We hypothesized that absence of CHF1/Hey2 would result in abnormal cellular electrical activity, altered cardiac conduction system (CCS) development, and increased arrhythmogenesis. We isolated neonatal CHF/Hey2-knockout (KO) cardiac myocytes and measured action potentials and ion channel subunit gene expression. We also crossed myocardial-specific CHF1/Hey2-KO mice with cardiac conduction system LacZ reporter mice and stained for conduction system tissue. We also performed ambulatory ECG monitoring for arrhythmias and heart rate variability. Neonatal cardiomyocytes from CHF1/Hey2-KO mice demonstrate a 50% reduction in action potential dV/dT, a 50-75% reduction in SCN5A, KCNJ2, and CACNA1C ion channel subunit gene expression, and an increase in delayed afterdepolarizations from 0/min to 12/min. CHF1/Hey2 cKO CCS-lacZ mice have a ∼3-fold increase in amount of CCS tissue. Ambulatory ECG monitoring showed no difference in cardiac conduction, arrhythmias, or heart rate variability. Wild-type cells or animals were used in all experiments. CHF1/Hey2 may contribute to Brugada syndrome by influencing the expression of SCN5A and formation of the cardiac conduction system, but its absence does not cause baseline conduction defects or arrhythmias in the adult mouse.-Hartman, M. E., Liu, Y., Zhu, W.-Z., Chien, W.-M., Weldy, C. S., Fishman, G. I., Laflamme, M. A., Chin, M. T. Myocardial deletion of transcription factor CHF1/Hey2 results in altered myocyte action potential and mild conduction system expansion but does not alter conduction system function or promote spontaneous arrhythmias. © FASEB.
Durand, Eric; Doutriaux, Maxime; Bettinger, Nicolas; Tron, Christophe; Fauvel, Charles; Bauer, Fabrice; Dacher, Jean-Nicolas; Bouhzam, Najime; Litzler, Pierre-Yves; Cribier, Alain; Eltchaninoff, Hélène
2017-12-11
The aim of this study was to assess the incidence, prognostic impact, and predictive factors of readmission for congestive heart failure (CHF) in patients with severe aortic stenosis treated by transcatheter aortic valve replacement (TAVR). TAVR is indicated in patients with severe symptomatic aortic stenosis in whom surgery is considered high risk or is contraindicated. Readmission for CHF after TAVR remains a challenge, and data on prognostic and predictive factors are lacking. All patients who underwent TAVR from January 2010 to December 2014 were included. Follow-up was achieved for at least 1 year and included clinical and echocardiographic data. Readmission for CHF was analyzed retrospectively. This study included 546 patients, 534 (97.8%) of whom were implanted with balloon-expandable valves preferentially via the transfemoral approach in 87.8% of cases. After 1 year, 285 patients (52.2%) had been readmitted at least once, 132 (24.1%) for CHF. Patients readmitted for CHF had an increased risk for death (p < 0.0001) and cardiac death (p < 0.0001) compared with those not readmitted for CHF. On multivariate analysis, aortic mean gradient (hazard ratio [HR]: 0.88; 95% confidence interval [CI]: 0.79 to 0.99; p = 0.03), post-procedural blood transfusion (HR: 2.27; 95% CI: 1.13 to 5.56; p = 0.009), severe post-procedural pulmonary hypertension (HR: 1.04; 95% CI: 1.00 to 1.07; p < 0.0001), and left atrial diameter (HR: 1.47; 95% CI: 1.08 to 2.01; p = 0.02) were independently associated with CHF readmission at 1 year. Readmission for CHF after TAVR was frequent and was strongly associated with 1-year mortality. Low gradient, persistent pulmonary hypertension, left atrial dilatation, and transfusions were predictive of readmission for CHF. Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.
Yao, Wei; Wang, Neng; Qian, Jin; Bai, Lu; Zheng, Xiaoxin; Hou, Guo; Qiu, Xuan; Yang, Bo
2017-11-01
Chronic congestive heart failure (CHF) is the end outcome of organic heart diseases and one of the major diseases harmful to human health. Renal sympathetic denervation (RSD) is the anatomical basis of transcatheter renal sympathetic nerve ablation within the renal artery. To date, the roles of norepinephrine and angiotensin II (Ang II) in myocardial apoptosis and their underlying mechanisms have not been well explored. The aim of the present study was to verify the hypothesis that RSD is likely to inhibit myocardial apoptosis by inhibiting the release of norepinephrine and Ang II. An isoproterenol-induced CHF rat model was established, and the effects of RSD on myocardial apoptosis were examined using flow cytometry and TUNEL staining. The expression of factors associated with myocardial apoptosis, including p53, tumor necrosis factor-α (TNF-α), nuclear factor-κB (NF-κB), caspase-2 and -3, were measured using quantitative polymerase chain reaction and western blot analysis. The results indicated that the mRNA levels of p53, TNF-α, NF-κB, caspase-2 and -3 were significantly reduced in the myocardial tissues of rats in the CHF+RSD group when compared with the levels in the CHF+sham group (P<0.01 for all). In addition, the protein levels of p53, TNF-α, NF-κB and caspases-2 and -3 were decreased by 42.6, 41.3, 46.7, 30.0 and 35.8%, respectively, in myocardial tissues of rats in the CHF+RSD group in comparison with the CHF+sham group (P<0.01 for all). Furthermore, myocardial apoptosis was improved in rats in the CHF+RSD group compared with that in the CHF+sham group (P<0.01). In conclusion, the present study provides a theoretical basis for application of RSD in the treatment of CHF.
Yao, Wei; Wang, Neng; Qian, Jin; Bai, Lu; Zheng, Xiaoxin; Hou, Guo; Qiu, Xuan; Yang, Bo
2017-01-01
Chronic congestive heart failure (CHF) is the end outcome of organic heart diseases and one of the major diseases harmful to human health. Renal sympathetic denervation (RSD) is the anatomical basis of transcatheter renal sympathetic nerve ablation within the renal artery. To date, the roles of norepinephrine and angiotensin II (Ang II) in myocardial apoptosis and their underlying mechanisms have not been well explored. The aim of the present study was to verify the hypothesis that RSD is likely to inhibit myocardial apoptosis by inhibiting the release of norepinephrine and Ang II. An isoproterenol-induced CHF rat model was established, and the effects of RSD on myocardial apoptosis were examined using flow cytometry and TUNEL staining. The expression of factors associated with myocardial apoptosis, including p53, tumor necrosis factor-α (TNF-α), nuclear factor-κB (NF-κB), caspase-2 and −3, were measured using quantitative polymerase chain reaction and western blot analysis. The results indicated that the mRNA levels of p53, TNF-α, NF-κB, caspase-2 and −3 were significantly reduced in the myocardial tissues of rats in the CHF+RSD group when compared with the levels in the CHF+sham group (P<0.01 for all). In addition, the protein levels of p53, TNF-α, NF-κB and caspases-2 and −3 were decreased by 42.6, 41.3, 46.7, 30.0 and 35.8%, respectively, in myocardial tissues of rats in the CHF+RSD group in comparison with the CHF+sham group (P<0.01 for all). Furthermore, myocardial apoptosis was improved in rats in the CHF+RSD group compared with that in the CHF+sham group (P<0.01). In conclusion, the present study provides a theoretical basis for application of RSD in the treatment of CHF. PMID:29104628
Yeh, Jiann-Horng; Huang, Chun-Ta; Liu, Chia-Hsiung; Ruan, Sheng-Yuan; Tsai, Yi-Ju; Chien, Ying-Chun; Yang, Ching-Yao; Huang, Chun-Kai; Hsu, Chia-Lin; Kuo, Lu-Cheng; Lee, Pei-Lin; Ku, Shih-Chi; Kuo, Ping-Hung; Yu, Chong-Jen
2014-01-01
Background and Objective Several studies on diagnostic accuracy of pleural N-terminal pro-B-type natriuretic peptide (NT-pro-BNP) for effusions from congestive heart failure (CHF) conclude that pleural NT-pro-BNP is a useful biomarker with high diagnostic accuracy for distinguishing CHF effusions. However, its applicability in critical care settings remains uncertain and requires further investigations. Methods NT-proBNP was measured in pleural fluid samples of a prospective cohort of intensive care unit patients with pleural effusions. Receiver operating characteristic curve analysis was performed to determine diagnostic accuracy of pleural NT-proBNP for prediction of CHF effusions. Results One hundred forty-seven critically ill patients were evaluated, 38 (26%) with CHF effusions and 109 (74%) with non-CHF effusions of various causes. Pleural NT-proBNP levels were significantly elevated in patients with CHF effusions. Pleural NT-pro-BNP demonstrated the area under the curve of 0.87 for diagnosing effusions due to CHF. With a cutoff of 2200 pg/mL, pleural NT-proBNP displayed high sensitivity (89%) but moderate specificity (73%). Notably, 29 (27%) of 109 patients with non-CHF effusions had pleural NT-proBNP levels >2200 pg/mL and these patients were more likely to experience septic shock (18/29 vs. 10/80, P<0.001) or acute kidney injury (19/29 vs. 9/80, P<0.001). Conclusions Among critically ill patients, pleural NT-proBNP measurements remain a useful diagnostic aid in evaluation of pleural effusions. However, patients with non-CHF effusions may exhibit high pleural NT-proBNP concentrations if they suffer from septic shock or acute kidney injury. Accordingly, it is suggested that clinical context should be taken into account when interpreting pleural NT-proBNP values in critical care settings. PMID:25502236
Increasing self-knowledge: Utilizing tele-coaching for patients with congestive heart failure.
Rosen, Daniel; Berrios-Thomas, Saskia; Engel, Rafael J
2016-10-01
The objective was to assess self-care knowledge changes with dually eligible Medicare and Medicaid patients diagnosed with congestive heart failure (CHF), who received a telecoaching protocol integrating symptom monitoring with face-to-face video chat with a social worker. We recruited 45 patients with CHF from a regional managed care organization. Sessions via a Health Insurance Portability and Accountability Act-compliant tablet-based platform focused on educational information designed to improve patient self-care. Social workers administered the 13-item Member Confidence Measure (MCM) at baseline and at a 30-day follow-up period. Scores were recorded to measure differences in patients' understanding of CHF and related symptoms, their knowledge of the disease, and the behaviors necessary to prevent their symptoms from getting worse. Over the 30-day period, scores significantly (p < .01) increased on the total scale score and specific confidence measure subscales (symptom recognition, medication adherence, medical attention, healthy choices, and safety). Gender, race, and age were unrelated to these improvements. In addition, effect sizes for the sub-scales ranged from .54 to 1.08; the effect size of the intervention as expressed by the total scale score was 1.12. Overall, patients increased knowledge over a 30-day period. Tele-coaching by social workers holds promise as a feasible model for health education for high-risk populations.
Xia, Tingting; Chai, Xichen; Shen, Jiaqing
2017-01-01
Appetite loss is one complication of chronic heart failure (CHF), and its association with pancreatic exocrine insufficiency (PEI) is not well investigated in CHF. We attempted to detect the association between PEI and CHF-induced appetite. Patients with CHF were enrolled, and body mass index (BMI), left ventricular ejection fraction (LVEF), New York Heart Association (NYHA) cardiac function grading, B-type natriuretic peptide (BNP), serum albumin, pro-albumin and hemoglobin were evaluated. The pancreatic exocrine function was measured by fecal elastase-1 (FE-1) levels in the enrolled patients. Appetite assessment was tested by completing the simplified nutritional appetite questionnaire (SNAQ). The improvement of appetite loss by supplemented pancreatic enzymes was also researched in this study. The decrease of FE-1 levels was found in patients with CHF, as well as SNAQ scores. A positive correlation was observed between SNAQ scores and FE-1 levels (r = 0.694, p < 0.001). Pancreatic enzymes supplement could attenuate the decrease of SNAQ scores in CHF patients with FE-1 levels <200 μg/g stool and SNAQ < 14. Appetite loss is commonly seen in CHF, and is partially associated with pancreatic exocrine insufficiency. Oral pancreatic enzyme replacement therapy attenuates the chronic heart failure-induced appetite loss. These results suggest a possible pancreatic-cardiac relationship in chronic heart failure, and further experiment is needed for clarifying the possible mechanisms.
Varadarajan, Padmini; Gandhi, Siddharth; Sharma, Sanjay; Umakanthan, Branavan; Pai, Ramdas G
2006-10-01
Previous studies have shown low hemoglobin (Hb) to have an adverse effect on survival in patients with congestive heart failure (CHF) and reduced left ventricular (LV) ejection fraction (EF); but its effect on survival in patients with CHF and normal EF is not known. This study sought to determine whether low Hb has an effect on survival in patients with both CHF and normal EF. Detailed chart reviews were performed by medical residents on 2,246 patients (48% with normal EF) with a discharge diagnosis of CHF in a large tertiary care hospital from 1990 to 1999. The CHF diagnosis was validated using the Framingham criteria. Mortality data were obtained from the National Death Index. Survival analysis was performed using Kaplan-Meier and Cox regression models. By Kaplan-Meier analysis, low Hb (< 12 gm/dl) compared with normal hemoglobin was associated with a lower 5-year survival in patients with CHF and both normal (38 vs. 50%, p = 0.0008) and reduced (35 vs. 48%, p = 0.0009) EF. Using the Cox regression model, low Hb was an independent predictor of mortality after adjusting for age, gender, renal dysfunction, diabetes mellitus, hypertension, and EF in both groups of patients. Low Hb has an independent adverse effect on survival in patients with CHF and both normal and reduced EF in both groups of patients.
Thiazolidinediones and congestive heart failure in veterans with type 2 diabetes.
Toprani, A; Fonseca, V
2011-03-01
The thiazolidinedione (TZD) class of antihyperglycaemic agents has been shown to improve glycaemic control by improving peripheral insulin sensitivity but may worsen or precipitate congestive heart failure (CHF). Randomized controlled trials have shown an increased risk of CHF in patients treated with TZDs. The use of TZDs in clinical practice has the potential to increase morbidity and health care costs. The purpose of this study was to compare the incidence of CHF in TZD and non-TZD-treated patients in a clinical setting. A retrospective cohort study of all male patients with type 2 diabetes seen in the South Central US Veterans Administration health care network between 1 October 1996 and 31 December 2004. We constructed a Cox proportional hazards model to evaluate the impact of TZD therapy on time to incidence of CHF. Of 3956 patients, 29% (n = 1157) developed CHF during the study period. The incidence of CHF was higher in patients who received TZD medications than in those who received TZDs. After adjustment for multiple cardiac risk factors, the hazard ratio for the development of CHF for TZD versus non-TZD-treated patients was 0.69 with a 95% confidence interval of 0.60-0.79. Patients in this cohort who received TZD medications had a lower incidence of heart failure than patients who did not receive TZDs. © 2011 Blackwell Publishing Ltd.
Sudarshan, Vidya K; Acharya, U Rajendra; Oh, Shu Lih; Adam, Muhammad; Tan, Jen Hong; Chua, Chua Kuang; Chua, Kok Poo; Tan, Ru San
2017-04-01
Identification of alarming features in the electrocardiogram (ECG) signal is extremely significant for the prediction of congestive heart failure (CHF). ECG signal analysis carried out using computer-aided techniques can speed up the diagnosis process and aid in the proper management of CHF patients. Therefore, in this work, dual tree complex wavelets transform (DTCWT)-based methodology is proposed for an automated identification of ECG signals exhibiting CHF from normal. In the experiment, we have performed a DTCWT on ECG segments of 2s duration up to six levels to obtain the coefficients. From these DTCWT coefficients, statistical features are extracted and ranked using Bhattacharyya, entropy, minimum redundancy maximum relevance (mRMR), receiver-operating characteristics (ROC), Wilcoxon, t-test and reliefF methods. Ranked features are subjected to k-nearest neighbor (KNN) and decision tree (DT) classifiers for automated differentiation of CHF and normal ECG signals. We have achieved 99.86% accuracy, 99.78% sensitivity and 99.94% specificity in the identification of CHF affected ECG signals using 45 features. The proposed method is able to detect CHF patients accurately using only 2s of ECG signal length and hence providing sufficient time for the clinicians to further investigate on the severity of CHF and treatments. Copyright © 2017 Elsevier Ltd. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kwang-Won, Lee; Sang-Yong, Lee
1995-09-01
A mechanistic model for forced convective transition boiling has been developed to investigate transition boiling mechanisms and to predict transition boiling heat flux realistically. This model is based on a postulated multi-stage boiling process occurring during the passage time of the elongated vapor blanket specified at a critical heat flux (CHF) condition. Between the departure from nucleate boiling (DNB) and the departure from film boiling (DFB) points, the boiling heat transfer is established through three boiling stages, namely, the macrolayer evaporation and dryout governed by nucleate boiling in a thin liquid film and the unstable film boiling characterized by themore » frequent touches of the interface and the heated wall. The total heat transfer rates after the DNB is weighted by the time fractions of each stage, which are defined as the ratio of each stage duration to the vapor blanket passage time. The model predictions are compared with some available experimental transition boiling data. The parametric effects of pressure, mass flux, inlet subcooling on the transition boiling heat transfer are also investigated. From these comparisons, it can be seen that this model can identify the crucial mechanisms of forced convective transition boiling, and that the transition boiling heat fluxes including the maximum heat flux and the minimum film boiling heat flux are well predicted at low qualities/high pressures near 10 bar. In future, this model will be improved in the unstable film boiling stage and generalized for high quality and low pressure situations.« less
Boiling and quenching heat transfer advancement by nanoscale surface modification.
Hu, Hong; Xu, Cheng; Zhao, Yang; Ziegler, Kirk J; Chung, J N
2017-07-21
All power production, refrigeration, and advanced electronic systems depend on efficient heat transfer mechanisms for achieving high power density and best system efficiency. Breakthrough advancement in boiling and quenching phase-change heat transfer processes by nanoscale surface texturing can lead to higher energy transfer efficiencies, substantial energy savings, and global reduction in greenhouse gas emissions. This paper reports breakthrough advancements on both fronts of boiling and quenching. The critical heat flux (CHF) in boiling and the Leidenfrost point temperature (LPT) in quenching are the bottlenecks to the heat transfer advancements. As compared to a conventional aluminum surface, the current research reports a substantial enhancement of the CHF by 112% and an increase of the LPT by 40 K using an aluminum surface with anodized aluminum oxide (AAO) nanoporous texture finish. These heat transfer enhancements imply that the power density would increase by more than 100% and the quenching efficiency would be raised by 33%. A theory that links the nucleation potential of the surface to heat transfer rates has been developed and it successfully explains the current finding by revealing that the heat transfer modification and enhancement are mainly attributed to the superhydrophilic surface property and excessive nanoscale nucleation sites created by the nanoporous surface.
Lovering, Andrew T; Lozo, Mislav; Barak, Otto; Davis, James T; Lojpur, Mihajlo; Lozo, Petar; Čaljkušić, Krešimir; Dujić, Željko
2016-05-01
What is the central question of this study? Does a patent foramen ovale contribute to resting arterial hypoxaemia, defined as arterial oxygen saturation <95%, in subjects with chronic heart failure with or without pulmonary arterial hypertension? What is the main finding and its importance? The presence of a patent foramen ovale contributed to resting arterial hypoxaemia only in subjects with chronic heart failure with pulmonary arterial hypertension. These data suggest that the presence of a patent foramen ovale should be considered in chronic heart failure patients with arterial hypoxaemia and pulmonary hypertension. The roles of intrapulmonary and intracardiac shunt in contributing to arterial hypoxaemia at rest in subjects with chronic heart failure (CHF) have not been well investigated. We hypothesized that blood flow through intrapulmonary arteriovenous anastomoses (Q̇ IPAVA ) and/or patent foramen ovale (Q̇ PFO ) could potentially contribute to arterial hypoxaemia and, with pulmonary hypertension (PH) secondary to CHF, this contribution may be exacerbated. Fifty-six subjects with CHF (New York Heart Association Classes I-III), with (+) or without (-) PH [defined as peak tricuspid regurgitation velocity ≥2.9 m s(-1) (CHF PH+, n = 32) and peak tricuspid regurgitation velocity ≤2.8 m s(-1) (CHF PH-, n = 24)], underwent arterial blood gas analysis and transthoracic saline contrast echocardiography concomitant with transcranial Doppler to detect Q̇ IPAVA and Q̇ PFO . Seventeen of 56 subjects with CHF (30%) had Q̇ PFO , but only four of 56 subjects with CHF had Q̇ IPAVA (7%), both similar to age- and sex-matched control subjects. Mean arterial oxygen saturation (SaO2) was lower in subjects with Q̇ PFO . Only CHF PH+ subjects with Q̇ PFO had arterial hypoxaemia (mean SaO2 <95%). Bubble scores assessed using transthoracic saline contrast echocardiography were correlated with microembolic signals detected with transcranial Doppler in subjects with Q̇ PFO . Significant Q̇ IPAVA was not present in either CHF PH+ or PH- subjects, suggesting that Q̇ IPAVA is not dependent on increased pulmonary pressure and does not contribute significantly to arterial hypoxaemia in older subjects with CHF. Given that SaO2 was lower in all subjects with CHF who had Q̇ PFO compared with those without Q̇ PFO , a patent foramen ovale should be considered when determining potential causes of arterial hypoxaemia, because Q̇ PFO was present in 30% of these subjects. © 2016 The Authors. Experimental Physiology © 2016 The Physiological Society.
Jaffuel, Dany; Molinari, Nicolas; Berdague, Philippe; Pathak, Atul; Galinier, Michel; Dupuis, Marion; Ricci, Jean‐Etienne; Mallet, Jean‐Pierre; Bourdin, Arnaud
2018-01-01
Abstract Aims Sleep‐disordered breathing (SDB) is a highly prevalent co‐morbidity in patients with chronic heart failure (CHF) and can play a detrimental role in the pathophysiology course of CHF. However, the best way to manage SDB in CHF remains a matter of debate. Sacubitril–valsartan has been included in the 2016 European Society of Cardiology guidelines as an alternative to angiotensin‐converting enzyme inhibitors to further reduce the risk of progression of CHF, CHF hospitalization, and death in ambulatory patients. Sacubitril and valsartan are good candidates for correcting SDB of CHF patients because their known mechanisms of action are likely to counteract the pathophysiology of SDB in CHF. Methods and results The ENTRESTO‐SAS trial is a 3‐month, multicentric, prospective, open‐label real‐life cohort study. Patients eligible for sacubitril–valsartan treatment (i.e. adults with left ventricular ejection fraction ≤35%, who remain symptomatic despite optimal treatment with an angiotensin‐converting enzyme inhibitor, a beta‐blocker, and a mineralocorticoid receptor antagonist) will be evaluated before and after 3 months of treatment (nocturnal ventilatory polygraphy, echocardiography, laboratory testing, and quality‐of‐life and SDB questionnaires). The primary outcome is the change in the Apnoea–Hypopnoea Index, before and after 3 months of treatment. One hundred twenty patients are required to detect a significant 20% improvement of the Apnoea–Hypopnoea Index with a power of 90% at an alpha risk of 5%. Conclusions In the context of the SERVE‐HF study, physicians are waiting for new trials and alternative therapies. We sought to assess in the ENTRESTO‐SAS trial whether sacubitril–valsartan could improve the outcome of SDB in CHF patients. PMID:29469206
Muus, Kyle J; Knudson, Alana; Klug, Marilyn G; Gokun, Jane; Sarrazin, Mary; Kaboli, Peter
2010-01-01
Hospital re-admissions for patients with congestive heart failure (CHF) are relatively common and costly occurrences within the US health infrastructure, including the Veterans Affairs (VA) healthcare system. Little is known about CHF re-admissions among rural veteran patients, including the effects of socio-demographics and follow-up outpatient visits on these re-admissions. To examine socio-demographics of US veterans with CHF who had 30 day potentially preventable re-admissions and compare the effect of 30 day VA post-discharge service use on these re-admissions for rural- and urban-dwelling veterans. The 2005-2007 VA data were analyzed to examine patient characteristics and hospital admissions for 36 566 veterans with CHF. The CHF patients who were and were not re-admitted to a VA hospital within 30 days of discharge were identified. Logistic regression was used to examine and compare the effect of VA post-acute service use on re-admissions between rural- and urban-dwelling veterans. Re-admitted veterans tended to be older (p=.002), had disability status (p=.024) and had longer hospital stays (p<.001). Veterans Affairs follow-up visits were negatively associated with re-admissions for both rural and urban veterans with CHF (ORs 0.16-0.76). Rural veterans aged 65 years and older who had VA emergency room visits following discharge were at high risk for re-admission (OR=2.66). Post-acute follow-up care is an important factor for promoting recovery and good health among hospitalized veterans with CHF, regardless of their rural or urban residence. Older, rural veterans with CHF are in need of special attention for VA discharge planning and follow up with primary care providers.
Jayasena, Rajiv; Maiorana, Andrew; Dowling, Alison; Chen, Sheau Huey; Karunanithi, Mohan; Layland, Jamie; Edwards, Iain
2017-01-01
Introduction Chronic heart failure (CHF) is a life-threatening chronic disease characterised by periodic exacerbations and recurrent hospitalisations. In the management of CHF, patient compliance with evidence-based clinical guidelines is essential, but remains difficult practically. The objective of this study is to examine whether an Innovative Telemonitoring Enhanced Care Programme for CHF (ITEC-CHF) improves patients’ compliance, and associated health and economic outcomes. Methods and analysis An open multicentre randomised controlled trial has been designed. Patients will be recruited and randomised to receive either ITEC-CHF (n=150) or usual care CHF (n=150) for at least 6 months. ITEC-CHF combines usual care and an additional telemonitoring service including remote weight monitoring, structured telephone support and nurse-led collaborative care. The primary outcomes are the compliance rates with the best-practice guidelines for daily weight monitoring. The secondary outcomes include the compliance with other guideline recommendations (health maintenance, medication, diet and exercise), health (health-related quality of life, risk factors, functional capacity and psychological states) and economic outcomes related to the use of healthcare resources such as hospital readmissions and general practitioner/emergency department visits. Ethics and dissemination The clinical trial has been approved by Peninsula Health Human Research Ethics Committee (HREC Reference: HREC/14/PH/27), Royal Perth Hospital Human Research Ethics Committee (Reference: 15-081) and the Curtin University Human Research Ethics Committee (Reference: HR 181/2014). We will disseminate the final results to the public via conferences and journal publications. A final study report will also be provided to the ethics committees. Trial registration number Registered with Australian New Zealand Clinical Trial Registry (ACTRN12614000916640). PMID:28993389
Pazin-Filho, Antonio; Peitz, Pamela; Pianta, Thomas; Carson, Kathryn A; Russell, Stuart D; Boulware, Leigh Ebony; Coresh, Josef
2009-09-01
Disease management programs (DMPs) are developed to address the high morbi-mortality and costs of congestive heart failure (CHF). Most studies have focused on intensive programs in academic centers. Washington County Hospital (WCH) in Hagerstown, MD, the primary reference to a semirural county, established a CHF DMP in 2001 with standardized documentation of screening and participation. Linkage to electronic records and state vital statistics enabled examination of the CHF population including individuals participating and those ineligible for the program. All WCH inpatients with CHF International Classification of Diseases, Ninth Revision code in any position of the hospital list discharged alive. Of 4,545 consecutive CHF admissions, only 10% enrolled and of those only 52.2% made a call. Enrollment in the program was related to: age (OR 0.64 per decade older, 95% CI 0.58-0.70), CHF as the main reason for admission (OR 3.58, 95% CI 2.4-4.8), previous admission for CHF (OR 1.14, 95% CI 1.09-1.2), and shorter hospital stay (OR 0.94 per day longer, 95% CI 0.87-0.99). Among DMP participants mortality rates were lowest in the first month (80/1000 person-years) and increased subsequently. The opposite mortality trend occurred in nonenrolled groups with mortality in the first month of 814 per 1000 person-years in refusers and even higher in ineligible (1569/1000 person-years). This difference remained significant after adjustment. Re-admission rates were lower among participants who called consistently (adjusted incidence rate ratio 0.62, 95% CI 0.52-0.77). Only a small and highly select group participated in a low-intensity DMP for CHF in a community-based hospital. Design of DMPs should incorporate these strong selective factors to maximize program impact.
Silverberg, Donald S
2011-11-01
Anemia is common in Congestive Heart Failure (CHF) and is associated with an increased mortality, morbidity and progressive renal failure. The most common causes of the anemia in CHF are (1) the associated Chronic Kidney Disease (CKD), which causes depression of erythropoietin (EPO) production in the kidney, and (2) excessive cytokine production in CHF, which can cause both depression of erythropoietin production in the kidney and depression of erythropoietin response in the bone marrow. The cytokines can also induce iron deficiency by increasing hepcidin production from the liver, which both reduces gastrointestinal iron absorption and reduces iron release from iron stores located in the macrophages and hepatocytes. It appears that iron deficiency is very common in CHF and is rarely recognized or treated. The iron deficiency can cause a thrombocytosis that might contribute to cardiovascular complications in both CHF and CKD and is reversible with iron treatment. Thus, attempts to control this anemia in CHF will have to take into consideration both the use of both Erythropoiesis Stimulating Agents (ESA) such as EPO and oral and, probably more importantly, intravenous (IV) iron. Many studies of anemia in CHF with ESA and oral or IV iron and even with IV iron without ESA have shown a positive effect on hospitalization, New York Heart Association functional class, cardiac and renal function, quality of life, exercise capacity and reduced Beta Natriuretic Peptide and have not demonstrated an increase in cardiovascular damage related to the therapy. However, adequately powered long-term placebo-controlled studies of ESA and of IV iron in CHF are still needed and are currently being carried out.
Multidisciplinary management of chronic heart failure: principles and future trends.
Davidson, Patricia M; Newton, Phillip J; Tankumpuan, Thitipong; Paull, G; Dennison-Himmelfarb, Cheryl
2015-10-01
Globally, the management of chronic heart failure (CHF) challenges health systems. The high burden of disease and the costs associated with hospitalization adversely affect individuals, families, and society. Improved quality, access, efficiency, and equity of CHF care can be achieved by using multidisciplinary care approaches if there is adherence and fidelity to the program's elements. The goal of this article was to summarize evidence and make recommendations for advancing practice, education, research, and policy in the multidisciplinary management of patients with CHF. Essential elements of multidisciplinary management of CHF were identified from meta-analyses and clinical practice guidelines. The study factors were discussed from the perspective of the health care system, providers, patients, and their caregivers. Identified gaps in evidence were used to identify areas for future focus in CHF multidisciplinary management. Although there is high-level evidence (including several meta-analyses) for the efficacy of management programs for CHF, less evidence exists to determine the benefit attributable to individual program components or to identify the specific content of effective components and the manner of their delivery. Health care system, provider, and patient factors influence health care models and the effective management of CHF and require focus and attention. Extrapolating trial findings to clinical practice settings is limited by the heterogeneity of study populations and the implementation of models of intervention beyond academic health centers, where practice environments differ considerably. Ensuring that individual programs are both developed and assessed that consider these factors is integral to ensuring adherence and fidelity with the core dimensions of disease management necessary to optimize patient and organizational outcomes. Recognizing the complexity of the multidisciplinary CHF interventions will be important in advancing the design, implementation, and evaluation of the interventions. Copyright © 2015 Elsevier HS Journals, Inc. All rights reserved.
Yin, Xiaochen; Peng, Jinghua; Zhao, Liping; Yu, Yunpeng; Zhang, Xu; Liu, Ping; Feng, Qin; Hu, Yiyang; Pang, Xiaoyan
2013-05-01
Accumulating evidence indicates that disruption of the gut microbiota by a high-fat diet (HFD) may play a pivotal role in the progression of metabolic disorders such as non-alcoholic fatty liver disease (NAFLD). In this study, the structural changes of gut microbiota were analyzed in an HFD-induced NAFLD rat model during treatment with an ancient Chinese herbal formula (CHF) used in clinical practice -Qushi Huayu Fang. CHF treatment significantly reduced body weight, alleviated hepatic steatosis, and decreased the content of triglycerides and free fatty acids in the livers of the rats. Gut microbiota of treated and control rats were profiled with polymerase chain reaction-denaturing gradient gel electrophoresis and bar-coded pyrosequencing of the V3 region of 16S rRNA genes. Both analyses indicated that the CHF-treated group harbored significantly different gut microbiota from that of model rats. Partial least squares discriminant analysis and taxonomy-based analysis were further employed to identify key phylotypes responding to HFD and CHF treatment. Most notably, the genera Escherichia/Shigella, containing opportunistic pathogens, were significantly enriched in HFD-fed rats compared to controls fed normal chow (P<0.05) but they decreased to control levels after CHF treatment. Collinsella, a genus with short chain fatty acid producers, was significantly elevated in CHF-treated rats compared to HFD-fed rats (P<0.05). The results revealed that the bacterial profiles of HFD-induced rats could be modulated by the CHF. Elucidation of these differences in microbiota composition provided a basis for further understanding the pharmacological mechanism of the CHF. Copyright © 2013 Elsevier GmbH. All rights reserved.
Eriksson, Anders S; Häggström, Jens; Pedersen, Henrik Duelund; Hansson, Kerstin; Järvinen, Anna-Kaisa; Haukka, Jari; Kvart, Clarence
2014-09-01
To evaluate the predictive value of plasma N-terminal pro-atrial natriuretic peptide (NT-proANP) and nitric oxide end-products (NOx) as markers for progression of mitral regurgitation caused by myxomatous mitral valve disease. Seventy-eight privately owned Cavalier King Charles spaniels with naturally occurring myxomatous mitral valve disease. Prospective longitudinal study comprising 312 measurements over a 4.5 year period. Clinical values were recorded, NT-proANP concentrations were measured by radioimmunoassay, and NOx were analyzed colorimetrically. To predict congestive heart failure (CHF), Cox proportional hazards models with time-varying covariates were constructed. The hazard ratio for NT-proANP (per 1000 pmol/l increase) to predict future CHF was 6.7 (95% confidence interval, 3.6-12.5; p < 0.001). The median time to CHF for dogs with NT-proANP levels >1000 pmol/l was 11 months (95% confidence interval, 5.6-12.6 months), compared to 54 months (46 - infinity) for dogs with concentrations ≤ 1000 pmol/l (p < 0.001). Due to intra- and inter-individual variability, most corresponding analyses for NOx were insignificant but dogs reaching CHF had a lower mean NOx concentration than dogs not reaching CHF (23 vs. 28 μmol/l, p = 0.016). Risk of CHF increased with increase in heart rate (>130 beats per minute) and grade of murmur (≥ 3/6). The risk of CHF due to mitral regurgitation is increased in dogs with blood NT-proANP concentrations above 1000 pmol/l. Measurement of NT-proANP can be a valuable tool to identify dogs that may develop CHF within months. Copyright © 2014 Elsevier B.V. All rights reserved.
Sugihara, Masami; Odagiri, Fuminori; Suzuki, Takeshi; Murayama, Takashi; Nakazato, Yuji; Unuma, Kana; Yoshida, Ken-ichi; Daida, Hiroyuki; Sakurai, Takashi; Morimoto, Sachio; Kurebayashi, Nagomi
2013-01-01
Inherited dilated cardiomyopathy (DCM) is a progressive disease that often results in death from congestive heart failure (CHF) or sudden cardiac death (SCD). Mouse models with human DCM mutation are useful to investigate the developmental mechanisms of CHF and SCD, but knowledge of the severity of CHF in live mice is necessary. We aimed to diagnose CHF in live DCM model mice by measuring voluntary exercise using a running wheel and to determine causes of death in these mice. A knock-in mouse with a mutation in cardiac troponin T (ΔK210) (DCM mouse), which results in frequent death with a t(1/2) of 70 to 90 days, was used as a DCM model. Until 2 months of age, average wheel-running activity was similar between wild-type and DCM mice (approximately 7 km/day). At approximately 3 months, some DCM mice demonstrated low running activity (LO: <1 km/day) while others maintained high running activity (HI: >5 km/day). In the LO group, the lung weight/body weight ratio was much higher than that in the other groups, and the lungs were infiltrated with hemosiderin-loaded alveolar macrophages. Furthermore, echocardiography showed more severe ventricular dilation and a lower ejection fraction, whereas Electrocardiography (ECG) revealed QRS widening. There were two patterns in the time courses of running activity before death in DCM mice: deaths with maintained activity and deaths with decreased activity. Our results indicate that DCM mice with low running activity developed severe CHF and that running wheels are useful for detection of CHF in mouse models. We found that approximately half of ΔK210 DCM mice die suddenly before onset of CHF, whereas others develop CHF, deteriorate within 10 to 20 days, and die.
Influence of heart failure on resting lung volumes in patients with COPD
de Souza, Aline Soares; Sperandio, Priscila Abreu; Mazzuco, Adriana; Alencar, Maria Clara; Arbex, Flávio Ferlin; de Oliveira, Mayron Faria; O'Donnell, Denis Eunan; Neder, José Alberto
2016-01-01
ABSTRACT Objective: To evaluate the influence of chronic heart failure (CHF) on resting lung volumes in patients with COPD, i.e., inspiratory fraction-inspiratory capacity (IC)/TLC-and relative inspiratory reserve-[1 − (end-inspiratory lung volume/TLC)]. Methods: This was a prospective study involving 56 patients with COPD-24 (23 males/1 female) with COPD+CHF and 32 (28 males/4 females) with COPD only-who, after careful clinical stabilization, underwent spirometry (with forced and slow maneuvers) and whole-body plethysmography. Results: Although FEV1, as well as the FEV1/FVC and FEV1/slow vital capacity ratios, were higher in the COPD+CHF group than in the COPD group, all major "static" volumes-RV, functional residual capacity (FRC), and TLC-were lower in the former group (p < 0.05). There was a greater reduction in FRC than in RV, resulting in the expiratory reserve volume being lower in the COPD+CHF group than in the COPD group. There were relatively proportional reductions in FRC and TLC in the two groups; therefore, IC was also comparable. Consequently, the inspiratory fraction was higher in the COPD+CHF group than in the COPD group (0.42 ± 0.10 vs. 0.36 ± 0.10; p < 0.05). Although the tidal volume/IC ratio was higher in the COPD+CHF group, the relative inspiratory reserve was remarkably similar between the two groups (0.35 ± 0.09 vs. 0.44 ± 0.14; p < 0.05). Conclusions: Despite the restrictive effects of CHF, patients with COPD+CHF have relatively higher inspiratory limits (a greater inspiratory fraction). However, those patients use only a part of those limits, probably in order to avoid critical reductions in inspiratory reserve and increases in elastic recoil. PMID:27832235
Pügge, Carolin; Mediratta, Jai; Marcus, Noah J; Schultz, Harold D; Schiller, Alicia M; Zucker, Irving H
2016-02-01
Recent data suggest that exercise training (ExT) is beneficial in chronic heart failure (CHF) because it improves autonomic and peripheral vascular function. In this study, we hypothesized that ExT in the CHF state ameliorates the renal vasoconstrictor responses to hypoxia and that this beneficial effect is mediated by changes in α1-adrenergic receptor activation. CHF was induced in rabbits. Renal blood flow (RBF) and renal vascular conductance (RVC) responses to 6 min of 5% isocapnic hypoxia were assessed in the conscious state in sedentary (SED) and ExT rabbits with CHF with and without α1-adrenergic blockade. α1-adrenergic receptor expression in the kidney cortex was also evaluated. A significant decline in baseline RBF and RVC and an exaggerated renal vasoconstriction during acute hypoxia occurred in CHF-SED rabbits compared with the prepaced state (P < 0.05). ExT diminished the decline in baseline RBF and RVC and restored changes during hypoxia to those of the prepaced state. α1-adrenergic blockade partially prevented the decline in RBF and RVC in CHF-SED rabbits and eliminated the differences in hypoxia responses between SED and ExT animals. Unilateral renal denervation (DnX) blocked the hypoxia-induced renal vasoconstriction in CHF-SED rabbits. α1-adrenergic protein in the renal cortex of animals with CHF was increased in SED animals and normalized after ExT. These data provide evidence that the acute decline in RBF during hypoxia is caused entirely by the renal nerves but is only partially mediated by α1-adrenergic receptors. Nonetheless, α1-adrenergic receptors play an important role in the beneficial effects of ExT in the kidney. Copyright © 2016 the American Physiological Society.
Jaffuel, Dany; Molinari, Nicolas; Berdague, Philippe; Pathak, Atul; Galinier, Michel; Dupuis, Marion; Ricci, Jean-Etienne; Mallet, Jean-Pierre; Bourdin, Arnaud; Roubille, François
2018-06-01
Sleep-disordered breathing (SDB) is a highly prevalent co-morbidity in patients with chronic heart failure (CHF) and can play a detrimental role in the pathophysiology course of CHF. However, the best way to manage SDB in CHF remains a matter of debate. Sacubitril-valsartan has been included in the 2016 European Society of Cardiology guidelines as an alternative to angiotensin-converting enzyme inhibitors to further reduce the risk of progression of CHF, CHF hospitalization, and death in ambulatory patients. Sacubitril and valsartan are good candidates for correcting SDB of CHF patients because their known mechanisms of action are likely to counteract the pathophysiology of SDB in CHF. The ENTRESTO-SAS trial is a 3-month, multicentric, prospective, open-label real-life cohort study. Patients eligible for sacubitril-valsartan treatment (i.e. adults with left ventricular ejection fraction ≤35%, who remain symptomatic despite optimal treatment with an angiotensin-converting enzyme inhibitor, a beta-blocker, and a mineralocorticoid receptor antagonist) will be evaluated before and after 3 months of treatment (nocturnal ventilatory polygraphy, echocardiography, laboratory testing, and quality-of-life and SDB questionnaires). The primary outcome is the change in the Apnoea-Hypopnoea Index, before and after 3 months of treatment. One hundred twenty patients are required to detect a significant 20% improvement of the Apnoea-Hypopnoea Index with a power of 90% at an alpha risk of 5%. In the context of the SERVE-HF study, physicians are waiting for new trials and alternative therapies. We sought to assess in the ENTRESTO-SAS trial whether sacubitril-valsartan could improve the outcome of SDB in CHF patients. © 2018 The Authors. ESC Heart Failure published by John Wiley & Sons Ltd on behalf of the European Society of Cardiology.
Elephantiasis Nostras Verrucosa (ENV): a complication of congestive heart failure and obesity.
Baird, Drew; Bode, David; Akers, Troy; Deyoung, Zachariah
2010-01-01
Congestive heart failure (CHF) and obesity are common medical conditions that have many complications and an increasing incidence in the United States. Presented here is a case of a disfiguring skin condition that visually highlights the dermatologic consequences of poorly controlled CHF and obesity. This condition will probably become more common as CHF and obesity increase in the US.
Congestive heart failure and central sleep apnea.
Sands, Scott A; Owens, Robert L
2015-07-01
Congestive heart failure (CHF) is among the most common causes of admission to hospitals in the United States, especially in those over age 65. Few data exist regarding the prevalence CHF of Cheyne-Stokes respiration (CSR) owing to congestive heart failure in the intensive care unit (ICU). Nevertheless, CSR is expected to be highly prevalent among those with CHF. Treatment should focus on the underlying mechanisms by which CHF increases loop gain and promotes unstable breathing. Few data are available to determine prevalence of CSR in the ICU, or how CSR might affect clinical management and weaning from mechanical ventilation. Copyright © 2015 Elsevier Inc. All rights reserved.
Congestive Heart Failure and Central Sleep Apnea.
Sands, Scott A; Owens, Robert L
2016-03-01
Congestive heart failure (CHF) is among the most common causes of admission to hospitals in the United States, especially in those over age 65. Few data exist regarding the prevalence CHF of Cheyne-Stokes respiration (CSR) owing to congestive heart failure in the intensive care unit (ICU). Nevertheless, CSR is expected to be highly prevalent among those with CHF. Treatment should focus on the underlying mechanisms by which CHF increases loop gain and promotes unstable breathing. Few data are available to determine prevalence of CSR in the ICU, or how CSR might affect clinical management and weaning from mechanical ventilation. Copyright © 2016 Elsevier Inc. All rights reserved.
Circular harmonic filters for the recognition of marine microorganisms
NASA Astrophysics Data System (ADS)
Zavala-Hamz, Victor Antonio; Alvarez-Borrego, Josué
1997-01-01
We present an application of circular-harmonic filters (CHF s) for the recognition of planktonic microorganisms. CHF s discriminated both genera Acartia and Calanus . The symmetry of genus Acartia permitted discrimination to the species and sex levels, whereas the asymmetry of the genus Calanus permitted discrimination only to the generic level. The differences among organisms of different sex of the genus Calanus could not be detected by these particular CHF s. More research needs to be carried out with more complex CHF s to enhance their performance and to permit the implementation of an automated optodigital system to identify and count marine microorganisms.
Gavin, A D; Struthers, A D
2005-06-01
To study whether the effect of allopurinol on improvement of endothelial dysfunction in chronic heart failure (CHF) translates into improved exercise capacity and to examine whether allopurinol also improves B-type natriuretic peptide (BNP), the other important prognostic marker of CHF. Randomised, double blind, placebo controlled crossover trial. Teaching hospital. 50 patients with CHF (New York Heart Association functional classes II and III) were recruited. 50 patients with CHF were randomly assigned to three months' treatment with allopurinol (300 mg/day) or placebo. At two and three months into treatment, they underwent a modified Bruce exercise protocol and a six minute walk test. Blood was taken for BNP and haemoglobin analysis. Neither exercise test was altered by allopurinol. However, plasma BNP concentrations fell significantly (p = 0.035) with allopurinol (11.9 pmol/l) versus placebo (14.4 pmol/l). Haemoglobin concentrations also fell highly significantly with allopurinol (p = 0.001). An important negative finding is that despite high hopes for it, allopurinol had no effect on exercise capacity in CHF. On the other hand, allopurinol did reduce BNP, which is the best available surrogate marker for prognosis in CHF.
2017-01-01
Background Appetite loss is one complication of chronic heart failure (CHF), and its association with pancreatic exocrine insufficiency (PEI) is not well investigated in CHF. Aim We attempted to detect the association between PEI and CHF-induced appetite. Methods Patients with CHF were enrolled, and body mass index (BMI), left ventricular ejection fraction (LVEF), New York Heart Association (NYHA) cardiac function grading, B-type natriuretic peptide (BNP), serum albumin, pro-albumin and hemoglobin were evaluated. The pancreatic exocrine function was measured by fecal elastase-1 (FE-1) levels in the enrolled patients. Appetite assessment was tested by completing the simplified nutritional appetite questionnaire (SNAQ). The improvement of appetite loss by supplemented pancreatic enzymes was also researched in this study. Results The decrease of FE-1 levels was found in patients with CHF, as well as SNAQ scores. A positive correlation was observed between SNAQ scores and FE-1 levels (r = 0.694, p < 0.001). Pancreatic enzymes supplement could attenuate the decrease of SNAQ scores in CHF patients with FE-1 levels <200 μg/g stool and SNAQ < 14. Conclusions Appetite loss is commonly seen in CHF, and is partially associated with pancreatic exocrine insufficiency. Oral pancreatic enzyme replacement therapy attenuates the chronic heart failure-induced appetite loss. These results suggest a possible pancreatic-cardiac relationship in chronic heart failure, and further experiment is needed for clarifying the possible mechanisms. PMID:29155861
Digital vs. conventional implant prosthetic workflows: a cost/time analysis.
Joda, Tim; Brägger, Urs
2015-12-01
The aim of this prospective cohort trial was to perform a cost/time analysis for implant-supported single-unit reconstructions in the digital workflow compared to the conventional pathway. A total of 20 patients were included for rehabilitation with 2 × 20 implant crowns in a crossover study design and treated consecutively each with customized titanium abutments plus CAD/CAM-zirconia-suprastructures (test: digital) and with standardized titanium abutments plus PFM-crowns (control conventional). Starting with prosthetic treatment, analysis was estimated for clinical and laboratory work steps including measure of costs in Swiss Francs (CHF), productivity rates and cost minimization for first-line therapy. Statistical calculations were performed with Wilcoxon signed-rank test. Both protocols worked successfully for all test and control reconstructions. Direct treatment costs were significantly lower for the digital workflow 1815.35 CHF compared to the conventional pathway 2119.65 CHF [P = 0.0004]. For subprocess evaluation, total laboratory costs were calculated as 941.95 CHF for the test group and 1245.65 CHF for the control group, respectively [P = 0.003]. The clinical dental productivity rate amounted to 29.64 CHF/min (digital) and 24.37 CHF/min (conventional) [P = 0.002]. Overall, cost minimization analysis exhibited an 18% cost reduction within the digital process. The digital workflow was more efficient than the established conventional pathway for implant-supported crowns in this investigation. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Telemedicine Facilitates CHF Home Health Care for Those with Systolic Dysfunction
Seibert, Pennie S.; Whitmore, Tiffany A.; Patterson, Carin; Parker, Patrick D.; Otto, Caitlin; Basom, Jean; Whitener, Nichole; Zimmerman, Christian G.
2008-01-01
An estimated 5 million Americans have congestive heart failure (CHF) and one in five over the age of 40 will develop CHF. There are numerous examples of CHF patients living beyond the years normally expected for people with the disease, usually attributed to taking an active role in disease management. A relatively new alternative for CHF outpatient care is telemedicine and e-health. We investigated the effects of a 6-week in-home telemedicine education and monitoring program for those with systolic dysfunction on the utilization of health care resources. We also measured the effects of the unit 4.5 months after its removal (a total of 6 months post introduction of the unit into the home). Concurrently, we assessed participants' perceptions of the value of having a telemedicine unit. Participants in the telemedicine group reported weighing more times a week with less variability than did the control group. Telemedicine led to a reduction in physician and emergency department visits and those in the experimental group reported the unit facilitating self-care, though this was not significantly different from the control group (possibly due to small sample size). These findings suggest a possibility for improvement in control of CHF when telemedicine is implemented. Our review of the literature also supports the role of telemedicine in facilitating home health care and self-management for CHF patients. There are many challenges still to be addressed before this potential can be reached and further research is needed to identify opportunities in telemedicine. PMID:18369411
Ambulatory Monitoring of Congestive Heart Failure by Multiple Bioelectric Impedance Vectors
Khoury, Dirar S.; Naware, Mihir; Siou, Jeff; Blomqvist, Andreas; Mathuria, Nilesh S.; Wang, Jianwen; Shih, Hue-Teh; Nagueh, Sherif F.; Panescu, Dorin
2009-01-01
Objectives To investigate properties of multiple bioelectric impedance signals recorded during congestive heart failure (CHF) by utilizing various electrode configurations of an implanted cardiac resynchronization therapy (CRT) system. Background Monitoring of CHF has relied mainly on right-heart sensors. Methods Fifteen normal dogs underwent implantation of CRT systems using standard leads. An additional left atrial (LA) pressure lead-sensor was implanted in 5 dogs. Continuous rapid right ventricular (RV) pacing was applied over several weeks. Left ventricular (LV) catheterization and echocardiography were performed biweekly. Six steady-state impedance signals, utilizing intrathorcaic and intracardiac vectors, were measured via ring (r), coil (c), and device Can electrodes. Results All animals developed CHF after 2–4 weeks of pacing. Impedance diminished gradually during CHF induction, but at varying rates for different vectors. Impedance during CHF decreased significantly in all measured vectors: LVr-Can, −17%; LVr-RVr, −15%; LVr-RAr, −11%; RVr-Can, −12%; RVc-Can, −7%; RAr-Can, −5%. The LVr-Can vector reflected both the fastest and largest change in impedance in comparison to vectors employing only right-heart electrodes, and was highly reflective of changes in LV end-diastolic volume and LA pressure. Conclusions Impedance, acquired via different lead-electrodes, have variable responses to CHF. Impedance vectors employing a LV lead are highly responsive to physiologic changes during CHF. Measuring multiple impedance signals could be useful for optimizing ambulatory monitoring in heart failure patients. PMID:19298923
Rotational modulation of the chromospheric activity in the young solar-type star, X-1 Orionis
NASA Technical Reports Server (NTRS)
Boesgaard, A. M.; Simon, T.
1982-01-01
The IUE satellite was used to observe one of the youngest G stars (GO V) for which Duncan (1981) derives an age of 6 x 10 to the 8th power years from the Li abundance. Rotational modulation was looked for in the emission flux in the chromospheric and transition region lines of this star. Variations in the Ca 11 K-lines profile were studied with the CHF telescope at Mauna Kea. Results show that the same modulation of the emission flux of Ca 11 due to stellar rotation is present in the transition region feature of C IV and probably of He II. For other UV lines the modulation is not apparent, due to a more complex surface distribution of the active areas or supergranulation network, or a shorter lifetime of the conditions which give rise to these features, or to the uncertainities in the measured line strengths. The Mg II emission flux is constant to within + or - 3.4% implying a rather uniform distribution of Mg II emission areas. The Ca II emission not only shows a measurable variation in intensity but also variations in detailed line profile shape when observed at high resolution.
Principi, T; Falzetti, G; Elisei, D; Donati, A; Pelaia, P
2009-04-01
The behavior of B-type natriuretic peptide (BNP) is assessed during mechanical ventilation (MV) and spontaneous breathing after extubation in critical patients. Thirty patients admitted in the Intensive Care Unit (ICU) were enrolled. BNP, fluid balance (FB), airway pressure (AP) and dobutamine infusion needing (DP) were registered in three stages: T0, admission to ICU; T1, before extubation; T2, 24 h after extubation. Patients with congestive heart failure (CHF) had BNP values higher than other patients. The value of BNP during MV was greater than normal in all patients. The cut-off to discriminate patients with heart failure during MV was 286 pgxmL(-1)(sensitivity: 86%; specificity: 90%). The increase of BNP during MV directly correlated with FB and inversely correlated with AP and DP. The plasmatic level of BNP remained higher than normal values 24 h after extubation. The underlying disease of an ICU patient seems to play a relevant role for BNP production and is probably linked to different aspects of therapeutic approach required by the patient. Our data suggest a cut-off value of BNP higher than the usual is necessary to discriminate mechanically-ventilated patients without CHF. This study should be repeated with an enlarged population.
Cheyne-Stokes respiration in patients with congestive heart failure.
Brack, Thomas
2003-12-13
Cheyne-Stokes Respiration (CSR) is a breathing pattern characterised by rhythmic oscillation of tidal volume with regularly recurring periods of hyperpnoea, hypopnoea and apnoea. CSR is no longer solely regarded as a symptom of severe congestive heart failure (CHF), but has been recognised as an independent risk factor for worsening heart failure and reduced survival in patients with CHF. CSR is associated with frequent awakening that fragment sleep and with concomitant sympathetic activation both of which may worsen CHF. Cheyne-Stokes Respiration is very common in patients with severe CHF and its prevalence may have been underestimated in the past due to technical limitations that precluded respiratory monitoring outside sleep laboratories. Since treatment of CSR appears to be beneficial and safe, patients at risk should be promptly diagnosed and treated. Treatment of CSR has been demonstrated to improve left ventricular ejection fraction and potentially prolongs survival in patients with severe CHF. This article briefly summarises the current knowledge of the patho-physiology, prevalence and therapy of Cheyne-Stokes respiration.
Lowery, Julie; Hopp, Faith; Subramanian, Usha; Wiitala, Wyndy; Welsh, Deborah E; Larkin, Angela; Stemmer, Karen; Zak, Cassandra; Vaitkevicius, Peter
2012-01-01
While disease management appears to be effective in selected, small groups of CHF patients from randomized controlled trials, its effectiveness in a broader CHF patient population is not known. This prospective, quasi-experimental study compared patient outcomes under a nurse practitioner-led disease management model (intervention group) with outcomes under usual care (control group) in both primary and tertiary medical centers. The study included 969 veterans (458 intervention, 511 control) treated for CHF at six VA medical centers. Intervention patients had significantly fewer (p<0.05) CHF and all-cause admissions at one-year follow-up, and lower mortality at both one- and two-year follow-up. These data provide support for the potential effectiveness of the intervention, and suggest that the evidence from RCTs of disease management models for CHF can be translated into clinical practice, even without the benefits of a selected patient population and dedicated resources often found in RCTs. © 2011 Wiley Periodicals, Inc.
NASA Astrophysics Data System (ADS)
Kuntamalla, Srinivas; Lekkala, Ram Gopal Reddy
2014-10-01
Heart rate variability (HRV) is an important dynamic variable of the cardiovascular system, which operates on multiple time scales. In this study, Multiscale entropy (MSE) analysis is applied to HRV signals taken from Physiobank to discriminate Congestive Heart Failure (CHF) patients from healthy young and elderly subjects. The discrimination power of the MSE method is decreased as the amount of the data reduces and the lowest amount of the data at which there is a clear discrimination between CHF and normal subjects is found to be 4000 samples. Further, this method failed to discriminate CHF from healthy elderly subjects. In view of this, the Reduced Data Dualscale Entropy Analysis method is proposed to reduce the data size required (as low as 500 samples) for clearly discriminating the CHF patients from young and elderly subjects with only two scales. Further, an easy to interpret index is derived using this new approach for the diagnosis of CHF. This index shows 100 % accuracy and correlates well with the pathophysiology of heart failure.
Wenchi Jin; Hong S. He; Frank R. Thompson; Wen J. Wang; Jacob S. Fraser; Stephen R. Shifley; Brice B. Hanberry; William D. Dijak
2017-01-01
The Central Hardwood Forest (CHF) in the United States is currently a major carbon sink, there are uncertainties in how long the current carbon sink will persist and if the CHF will eventually become a carbon source. We used a multi-model ensemble to investigate aboveground carbon density of the CHF from 2010 to 2300 under current climate. Simulations were done using...
An Investigation of Emotion Recognition and Theory of Mind in People with Chronic Heart Failure
Habota, Tina; McLennan, Skye N.; Cameron, Jan; Ski, Chantal F.; Thompson, David R.; Rendell, Peter G.
2015-01-01
Objectives Cognitive deficits are common in patients with chronic heart failure (CHF), but no study has investigated whether these deficits extend to social cognition. The present study provided the first empirical assessment of emotion recognition and theory of mind (ToM) in patients with CHF. In addition, it assessed whether each of these social cognitive constructs was associated with more general cognitive impairment. Methods A group comparison design was used, with 31 CHF patients compared to 38 demographically matched controls. The Ekman Faces test was used to assess emotion recognition, and the Mind in the Eyes test to measure ToM. Measures assessing global cognition, executive functions, and verbal memory were also administered. Results There were no differences between groups on emotion recognition or ToM. The CHF group’s performance was poorer on some executive measures, but memory was relatively preserved. In the CHF group, both emotion recognition performance and ToM ability correlated moderately with global cognition (r = .38, p = .034; r = .49, p = .005, respectively), but not with executive function or verbal memory. Conclusion CHF patients with lower cognitive ability were more likely to have difficulty recognizing emotions and inferring the mental states of others. Clinical implications of these findings are discussed. PMID:26529409
Sakai, Hiroshi; Tsutamoto, Takayoshi; Tsutsui, Takashi; Tanaka, Toshinari; Ishikawa, Chitose; Horie, Minoru
2006-08-01
A recent study suggested that xanthine oxidase is activated in congestive heart failure (CHF). However, whether uric acid (UA) is secreted from the failing heart remains unknown, so it is currently unclear whether serum UA can provide prognostic information independent of brain natriuretic peptide (BNP). Serum UA was measured in the aortic root (AO) and the coronary sinus (CS) of 74 patients with CHF. The serum UA level was significantly higher in the CS than in the AO. The transcardiac gradient of UA (CS-AO) increased with the severity of CHF, inversely correlated with left ventricular ejection fraction (LVEF) and positively correlated with left ventricular end-diastolic volume index. The plasma levels of norepinephrine, BNP, UA, and LVEF were monitored prospectively in 150 CHF patients for a mean follow-up of 3 years. High plasma levels of UA (p<0.001) and BNP (p<0.001) were shown by multivariate stepwise analysis to be independent predictors of mortality. High plasma UA level, partly secreted from the failing heart, is a prognostic predictor independent of BNP in patients with CHF. Monitoring a combination of BNP and UA may be useful for the management of patients with CHF.
Glaser, Kirsten; Fehrholz, Markus; Henrich, Birgit; Claus, Heike; Papsdorf, Michael; Speer, Christian P
2017-02-01
Synthetic surfactants represent a promising alternative to animal-derived preparations in the treatment of neonatal respiratory distress syndrome. The synthetic surfactant CHF5633 has proven biophysical effectiveness and, moreover, demonstrated anti-inflammatory effects in LPS-stimulated monocytes. With ureaplasmas being relevant pathogens in preterm lung inflammation, the present study addressed immunomodulatory features on Ureaplasma-induced monocyte cytokine responses. Ureaplasma parvum-stimulated monocytes were exposed to CHF5633. TNF-α, IL-1β, IL-8, IL-10, TLR2 and TLR4 expression were analyzed using qPCR and flow cytometry. CHF5633 did not induce pro-inflammation, and did not aggravate Ureaplasma-induced pro-inflammatory cytokine responses. It suppressed U. parvum-induced intracellular TNF-α (p < 0.05) and IL-1β (p < 0.05) in neonatal monocytes and inhibited Ureaplasma-induced TNF-α mRNA (p < 0.05), TNF-α protein (p < 0.001), and IL-1β (p = 0.05) in adult monocytes. Ureaplasma-modulated IL-8, IL-10, TLR2 and TLR4 were unaffected. CHF5633 does neither act pro-apoptotic nor pro-inflammatory in native and Ureaplasma-infected monocytes. Suppression of Ureaplasma-induced TNF-α and IL-1β underlines anti-inflammatory features of CHF5633.
Lee, C W; Lee, J H; Kim, J J; Park, S W; Hong, M K; Kim, S T; Lim, T H; Park, S J
1999-04-01
Using proton magnetic resonance spectroscopy, we investigated cerebral metabolism and its determinants in congestive heart failure (CHF), and the effects of cardiac transplantation on these measurements. Few data are available about cerebral metabolism in CHF. Fifty patients with CHF (ejection fraction < or = 35%) and 20 healthy volunteers were included for this study. Of the patients, 10 patients underwent heart transplantation. All subjects performed symptom-limited bicycle exercise test. Proton magnetic resonance spectroscopy (1H MRS) was obtained from localized regions (8 to 10 ml) of occipital gray matter (OGM) and parietal white matter (PWM). Absolute levels of the metabolites (N-acetylaspartate, creatine, choline, myo-inositol) were calculated. In PWM only creatine level was significantly lower in CHF than in control subjects, but in OGM all four metabolite levels were decreased in CHF. The creatine level was independently correlated with half-recovery time and duration of heart failure symptoms in PWM (r = -0.56, p < 0.05), and with peak oxygen consumption and serum sodium concentration in OGM (r = 0.58, p < 0.05). Cerebral metabolic abnormalities were improved after successful cardiac transplantation. This study shows that cerebral metabolism is abnormally deranged in advanced CHF and it may serve as a potential marker of the disease severity.
Experimental evidence for the blue-shifted hydrogen-bonded complexes of CHF3 with π-electron donors.
Gopi, R; Ramanathan, N; Sundararajan, K
2017-06-15
Blue-shifted hydrogen-bonded complexes of fluoroform (CHF 3 ) with benzene (C 6 H 6 ) and acetylene (C 2 H 2 ) have been investigated using matrix isolation infrared spectroscopy and ab initio computations. For CHF 3 -C 6 H 6 complex, calculations performed at the B3LYP and MP2 levels of theory using 6-311++G (d,p) and aug-cc-pVDZ basis sets discerned two minima corresponding to a 1:1 hydrogen-bonded complex. The global minimum correlated to a structure, where the interaction is between the hydrogen of CHF 3 and the π-electrons of C 6 H 6 and a weak local minimum was stabilized through H…F interaction. For the CHF 3 -C 2 H 2 complex, computation performed at MP2/aug-cc-pVDZ level of theory yielded two minima, corresponding to the cyclic C-H…π complex A (global) and a linear C-H…F (n-σ) complex B (local). Experimentally a blue-shift of 32.3cm -1 and 7.7cm -1 was observed in the ν 1 C-H stretching mode of CHF 3 sub-molecule in Ar matrix for the 1:1 C-H…π complexes of CHF 3 with C 6 H 6 and C 2 H 2 respectively. Natural bond orbital (NBO), Atoms-in-molecule (AIM) and energy decomposition (EDA) analyses were carried out to explain the blue-shifting and the nature of the interaction in these complexes. Copyright © 2017 Elsevier B.V. All rights reserved.
Jung, SeungWoo; Bohan, Amy
2018-02-01
OBJECTIVE To characterize expression profiles of circulating microRNAs via genome-wide sequencing for dogs with congestive heart failure (CHF) secondary to myxomatous mitral valve degeneration (MMVD). ANIMALS 9 healthy client-owned dogs and 8 age-matched client-owned dogs with CHF secondary to MMVD. PROCEDURES Blood samples were collected before administering cardiac medications for the management of CHF. Isolated microRNAs from plasma were classified into microRNA libraries and subjected to next-generation sequencing (NGS) for genome-wide sequencing analysis and quantification of circulating microRNAs. Quantitative reverse transcription PCR (qRT-PCR) assays were used to validate expression profiles of differentially expressed circulating microRNAs identified from NGS analysis of dogs with CHF. RESULTS 326 microRNAs were identified with NGS analysis. Hierarchical analysis revealed distinct expression patterns of circulating microRNAs between healthy dogs and dogs with CHF. Results of qRT-PCR assays confirmed upregulation of 4 microRNAs (miR-133, miR-1, miR-let-7e, and miR-125) and downregulation of 4 selected microRNAs (miR-30c, miR-128, miR-142, and miR-423). Results of qRT-PCR assays were highly correlated with NGS data and supported the specificity of circulating microRNA expression profiles in dogs with CHF secondary to MMVD. CONCLUSIONS AND CLINICAL RELEVANCE These results suggested that circulating microRNA expression patterns were unique and could serve as molecular biomarkers of CHF in dogs with MMVD.
Lenk, Karsten; Erbs, Sandra; Höllriegel, Robert; Beck, Ephraim; Linke, Axel; Gielen, Stephan; Winkler, Sven Möbius; Sandri, Marcus; Hambrecht, Rainer; Schuler, Gerhard; Adams, Volker
2012-06-01
In chronic heart failure (CHF), cardiac cachexia is often associated with the terminal stage of this disease. In animal studies it has been demonstrated that myostatin, a key regulator of skeletal muscle mass, is elevated in advanced stages of this syndrome. The aim of the present study was to investigate the expression of myostatin in patients with late stage CHF (NYHA IIIb) in comparison to healthy subjects. Furthermore the effects of physical exercise on myostatin were analyzed. Twenty-four patients were either randomized to a sedentary control group (CHF-S) or exercise training (CHF-E). At baseline and after 12 weeks mRNA and myostatin protein in the peripheral skeletal muscle as well as myostatin serum concentration were measured. Furthermore 12 age-matched healthy men were compared to all patients at baseline (HC). CHF patients showed a two-fold increase of myostatin mRNA (p = 0.05) and a 1.7-fold (p = 0.01) augmentation of protein content in skeletal muscle compared to healthy subjects. In late-stage CHF, exercise training led to a 36% reduction of the mRNA and a 23% decrease of the myostatin protein compared to baseline. The serum concentration of myostatin revealed no significant alteration between the groups. In the skeletal muscle, myostatin increases significantly in the course of CHF. The observed effects of a significant reduction of myostatin in skeletal muscle after 12 weeks of exercise training demonstrate the reversibility of molecular changes that might be able to halt the devastating process of muscle wasting in chronic heart failure.
Täger, Tobias; Hanholz, Wiebke; Cebola, Rita; Fröhlich, Hanna; Franke, Jennifer; Doesch, Andreas; Katus, Hugo A; Wians, Frank H; Frankenstein, Lutz
2014-09-01
The 6-minute walk test (6 WT) is an established tool in the assessment of endurance and prognosis in patients with chronic heart failure (CHF). For these patients there is very limited data on biological variation of 6 WT distances. We determined the minimal important difference (MID) for the 6 WT in patients with stable systolic CHF. Two cohorts of patients with stable systolic CHF were included from the outpatients' clinic of the University of Heidelberg. In these cohorts, two 6 WT measurements were performed - in cohort 1 (n=461) 180 days and in cohort 2 (n=512) 365 days apart. Stability was defined as the absence of clinical events (3 months before the first test, between both tests, and 6 months after the second test) and stability of symptoms (NYHA) between tests. Using a standard error of measurement (SEM)-based approach, we determined the MID for both cohorts. The intraclass correlation coefficient was 0.89 at 180 days and 0.88 at 365 days. The results were consistent for groups stratified for age, gender, etiology of CHF, and individual NYHA class. The MID for the 6 WT in stable CHF patients was 35 m and 37 m between presentation and 180 and 365 days, respectively. Submaximal exercise capacity as represented by the 6 WT varies little in stable CHF patients for up to 1-year intervals. The MID for changes in 6 WT values in patients with stable CHF over a period of 6 to 12 months is ~ 36 m. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.
[Matrix metalloproteinases and their inhibitors in lung cancer with malignant pleural effusion].
Moche, M; Hui, D S C; Huse, K; Chan, K S; Choy, D K L; Scholz, G H; Gosse, H; Winkler, J; Schauer, J; Sack, U; Hoheisel, G
2005-08-01
Matrix metalloproteinases (MMP) and tissue inhibitors of metalloproteinases (TIMP) play a crucial role in physiological and pathological matrix turnover. This study aimed to determine the occurrence of MMP and TIMP in lung cancer patients with malignant pleural effusions (CA). MMP-1, MMP-2, MMP-3, MMP-8, MMP-9, TIMP-1, and IMP-2 oncentrations were determined by ELISA and zymography in pleural effusions and plasma of 31 CA and 14 congestive heart failure (CHF) patients and in plasma of 18 healthy controls (CON). MMP-2, TIMP-1, and TIMP-2 ELISA-concentrations were increased in CA pleural fluid vs. CA plasma (p < 0.005, p < 0.005, p < 0.05), in contrast to MMP-9 being higher in plasma (p < 0.005). Pleural fluid MMP-1 and MMP-8 were increased in CA vs. CHF (p < 0.05, p < 0.005). MMP and TIMP plasma concentrations were not different in CA vs. CHF, but MMP-9, TIMP-1, and TIMP-2 were increased vs. CON (p < 0.005, each). Gelatine zymography MMP-9/MMP-2 ratios were increased in CA plasma vs. effusion fluid (p < 0.005), in CA vs. CHF plasma, CA vs. CHF effusions (p < 0.005 each), and in CA vs. CON plasma (p < 0.05). MMP-2, TIMP-1, and TIMP-2 accumulate in the pleural compartment in CA and CHF, probably reflecting an unspecific pleural reaction. MMP-1 and MMP-8 are increased in cellular rich CA pleural effusions only. The determination of MMP-9/MMP-2 ratios in pleural fluid may contribute to differentiate CHF from CA effusions.
Whitty, Jennifer A; Carrington, Melinda J; Stewart, Simon; Holliday, Julie; Marwick, Thomas H; Scuffham, Paul A
2012-01-01
Chronic heart failure (CHF) management programs (CHF-MPs) are applied in different ways including via face-to-face settings. However, we know little about consumer preferences when applying CHF-MPs via a patient's home or specialist hospital clinic. The aim of this pilot study was to explore CHF-MP characteristics that are considered desirable by patients with CHF. Semistructured interviews with a purposive sample of 12 CHF patients. Participants had a mean age of 61 (SD, 17) years, 3 were female, and the majority was of white background. Most were assessed as either functional New York Heart Association class III (n = 3) or IV (n = 6). Home- and clinic-based CHF-MPs were preferred by 5 and 7 participants, respectively. Key themes around patient preferences related to practical aspects of program delivery and social and peer support, as well as health-related benefits that translate to traditional outcomes in program evaluations. Participants identified transport, cost, and ill health as barriers to attending a clinic-based program. However, they also highlighted benefits (eg, the ability to share experiences with other patients) that may be difficult to provide with a home-based service unless specifically organized. These preliminary data suggest that patients value aspects of a program beyond those directly related to health outcomes. They also recognize a need for flexibility in program delivery, with potential preferences for home- or clinic-based programs depending largely on individual patient circumstances. More definitive studies are required to explore how best to cater for individual preferences while optimizing health outcomes.
KANNO, Nobuyuki; HORI, Yasutomo; HIDAKA, Yuichi; CHIKAZAWA, Seishiro; KANAI, Kazutaka; HOSHI, Fumio; ITOH, Naoyuki
2015-01-01
The clinical utility of plasma natriuretic peptide concentrations in dogs with right-sided congestive heart failure (CHF) remains unclear. We investigated whether plasma levels of atrial natriuretic peptide (ANP) and N-terminal pro B-type natriuretic peptide (NT-proBNP) are useful for assessing the congestive signs of right-sided heart failure in dogs. This retrospective study enrolled 16 healthy dogs and 51 untreated dogs with presence (n=28) or absence (n=23) of right-sided CHF. Medical records of physical examinations, thoracic radiography and echocardiography were reviewed. The plasma concentration of canine ANP was measured with a chemiluminescent enzyme immunoassay. Plasma NT-proBNP concentrations were determined using an enzyme immunoassay. Plasma ANP and NT-proBNP concentrations in dogs with right-sided CHF were significantly higher than in healthy controls and those without right-sided CHF. The plasma NT-proBNP concentration >3,003 pmol/l used to identify right-sided CHF had a sensitivity of 88.5% and specificity of 90.3%. An area under the ROC curve (AUC) was 0.93. The AUC for NT-proBNP was significantly higher than the AUCs for the cardiothoracic ratio, vertebral heart score, ratio of right ventricular end-diastolic internal diameter to body surface area, tricuspid late diastolic flow and ratio of the velocities of tricuspid early to late diastolic flow. These results suggest that plasma ANP and NT-proBNP concentrations increase markedly in dogs with right-sided CHF. Particularly, NT-proBNP is simple and helpful biomarkers to assess the right-sided CHF. PMID:26607133
Frequency response of the renal vasculature in congestive heart failure.
DiBona, Gerald F; Sawin, Linda L
2003-04-29
The renal vasoconstrictor response to renal nerve stimulation is greater in congestive heart failure (CHF) rats than in control rats. This study tested the hypothesis that the enhanced renal vasoconstrictor response to renal nerve stimulation in CHF is a result of an impairment in the low-pass filter function of the renal vasculature. In response to conventional graded-frequency renal nerve stimulation, the reductions in renal blood flow at each stimulation frequency were greater in CHF rats than control rats. A pseudorandom binary sequence pattern of renal nerve stimulation was used to examine the frequency response of the renal vasculature. Although this did not affect the renal blood flow power spectrum in control rats, there was a 10-fold increase in renal blood flow power over the frequency range of 0.01 to 1.0 Hz in CHF rats. On analysis of transfer function gain, attenuation of the renal nerve stimulation input signal was similar in control and CHF rats over the frequency range of 0.001 to 0.1 Hz. However, over the frequency range of 0.1 to 1.0 Hz, although there was progressive attenuation of the input signal (-30 to -70 dB) in control rats, CHF rats exhibited a flat gain response (-20 dB) without progressive attenuation. The enhanced renal vasoconstrictor response to renal nerve stimulation in CHF rats is caused by an alteration in the low-pass filter function of the renal vasculature, resulting in a greater transfer of input signals into renal blood flow in the 0.1 to 1.0 Hz range.
Sun, Yu-Ping; Wang, Wen-Di; Ma, Shao-Chun; Wang, Li-Yan; Qiao, Ling-Yan; Zhang, Li-Ping
2013-02-01
To study serum levels of heart-type fatty acid-binding protein (h-FABP) in children with chronic heart failure (CHF), and the correlation between heart function and the level of h-FABP, with the aim of studying the significance of h-FABP in CHF. Thirty-six children with CHF, including 16 cases of endocardial fibroelastosis (EFE) and 20 cases of dilated cardiomyopathy (DCM) were enrolled in the study. Thirty healthy children sevred as the control group. Serum levels of h-FABP were determined using ELISA, and left ventricular ejection fraction (LVEF), cardiac index (CI) and fractional shortening of the left ventricle (LVSF) were measured by two-dimensional echocardiography in the CHF group. Mean levels of h-FABP in the CHF group were significantly higher than in the control group (21.7±4.3 ng/mL vs 6.2±1.7 ng/mL; P<0.01). The worse the heart function, the higher the h-FABP levels (P<0.01). Mean levels of h-FABP in both the EFE and DCM groups were significantly higher than in the control group (P<0.01). Serum h-FABP concentrations were negatively correlated with LVEF, CI and LVSF (r=-0.65, -0.64 and -0.71 respectively; P<0.01) in the CHF group. Serum h-FABP levels increase in children with CHF and are closely related to the severity of the condition. Serum h-FABP levels can be used as a biomarker for the diagnosis of heart failure and the evaluation of its severity.
López, Lenny; Cook, Nakela; Hicks, Leroi
2015-01-01
Primary care practices that concentrate linguistically and culturally appropriate services for Latinos may result in higher cardiology consultation rates and improved process measure performance for patients with coronary artery disease (CAD) and congestive heart failure (CHF). Multivariable Cox proportional-hazards regression was used to assess differences in referral at high proportion (HP) vs low proportion (LP) practices. Multivariable Poisson regression was used to assess the frequency of follow-up consultation. Among the 9,761 patients, 9,168 had CAD, 4,444 had CHF, and 3,851 had both conditions. Latinos comprised 11% of the CAD cohort and 11% of the CHF cohort. Multivariable analyses showed higher consultation rates for Latinos at HP practices for CAD and CHF. Blacks and Whites at HP practices had no significant differences in rates of consultation compared to those in LP practices. Latinos at HP practices had 25% more consultations for CAD and 23% more consultations for CHF than Latinos at LP practices. Latinos at HP clinics had higher overall mean quality performance on clinical measures for both CAD and CHF. Latinos at an LP clinic had the largest improvement in quality performance with consultation. Among Latinos with CAD or CHF receiving care within a single large academic care network, Latino patients at HP practices have higher rates of cardiologist consultation and performance on CVD process measures compared to Latino patients at LP practices. Elucidating the essential components of individual practice environments that provide higher quality of care for Latinos will allow for well designed systems to reduce health care disparities.
Risk distribution across multiple health insurance funds in rural Tanzania.
Chomi, Eunice Nahyuha; Mujinja, Phares Gamba; Enemark, Ulrika; Hansen, Kristian; Kiwara, Angwara Dennis
2014-01-01
Multiple insurance funds serving different population groups may compromise equity due to differential revenue raising capacity and an unequal distribution of high risk members among the funds. This occurs when the funds exist without mechanisms in place to promote income and risk cross-subsidisation across the funds. This paper analyses whether the risk distribution varies across the Community Health Fund (CHF) and National Health Insurance Fund (NHIF) in two districts in Tanzania. Specifically we aim to 1) identify risk factors associated with increased utilisation of health services and 2) compare the distribution of identified risk factors among the CHF, NHIF and non-member households. Data was collected from a survey of 695 households. A multivariate logisitic regression model was used to identify risk factors for increased health care utilisation. Chi-square tests were performed to test whether the distribution of identified risk factors varied across the CHF, NHIF and non-member households. There was a higher concentration of identified risk factors among CHF households compared to those of the NHIF. Non-member households have a similar wealth status to CHF households, but a lower concentration of identified risk factors. Mechanisms for broader risk spreading and cross-subsidisation across the funds are necessary for the promotion of equity. These include risk equalisation to adjust for differential risk distribution and revenue raising capacity of the funds. Expansion of CHF coverage is equally important, by addressing non-financial barriers to CHF enrolment to encourage wealthy non-members to join, as well as subsidised membership for the poorest.
Whitty, Jennifer A; Stewart, Simon; Carrington, Melinda J; Calderone, Alicia; Marwick, Thomas; Horowitz, John D; Krum, Henry; Davidson, Patricia M; Macdonald, Peter S; Reid, Christopher; Scuffham, Paul A
2013-01-01
Beyond examining their overall cost-effectiveness and mechanisms of effect, it is important to understand patient preferences for the delivery of different modes of chronic heart failure management programs (CHF-MPs). We elicited patient preferences around the characteristics and willingness-to-pay (WTP) for a clinic or home-based CHF-MP. A Discrete Choice Experiment was completed by a sub-set of patients (n = 91) enrolled in the WHICH? trial comparing home versus clinic-based CHF-MP. Participants provided 5 choices between hypothetical clinic and home-based programs varying by frequency of nurse consultations, nurse continuity, patient costs, and availability of telephone or education support. Participants (aged 71±13 yrs, 72.5% male, 25.3% NYHA class III/IV) displayed two distinct preference classes. A latent class model of the choice data indicated 56% of participants preferred clinic delivery, access to group CHF education classes, and lower cost programs (p<0.05). The remainder preferred home-based CHF-MPs, monthly rather than weekly visits, and access to a phone advice service (p<0.05). Continuity of nurse contact was consistently important. No significant association was observed between program preference and participant allocation in the parent trial. WTP was estimated from the model and a dichotomous bidding technique. For those preferring clinic, estimated WTP was ≈AU$9-20 per visit; however for those preferring home-based programs, WTP varied widely (AU$15-105). Patient preferences for CHF-MPs were dichotomised between a home-based model which is more likely to suit older patients, those who live alone, and those with a lower household income; and a clinic-based model which is more likely to suit those who are more socially active and wealthier. To optimise the delivery of CHF-MPs, health care services should consider their patients' preferences when designing CHF-MPs.
Albackr, Hanan B; Alhabib, Khalid F; Ullah, Anhar; Alfaleh, Hussam; Hersi, Ahmad; Alshaer, Fayez; Alnemer, Khalid; Al Saif, Shukri; Taraben, Amir; Kashour, Tarek
2013-11-01
The aim of this study was to assess the prevalence, clinical features, and in-hospital outcomes of heart failure in patients with acute coronary syndrome (ACS). The Saudi Project for Assessment of Coronary Events recruited patients admitted with ACS from 17 hospitals in Saudi Arabia from 2005 to 2007. The outcomes of ACS patients with congestive heart failure (CHF) compared with those without CHF were analyzed. A total of 4523 patients with ACS were identified, of whom 905 (20%) had CHF. Compared with no CHF, patients with CHF were older (62±13.1 vs. 57±12.9 years; P=0.001), less likely to be men (70 vs. 79%; P=0.001), likely to present with non-ST-segment elevation myocardial infarction (48 vs. 36%; P=0.001), likely to have diabetes (71 vs. 54%; P=0.001), hypertension (64 vs. 54%; P=0.001) and previous history of coronary artery disease (53 vs. 43%; P=0.001), and likely to have significant left ventricular systolic dysfunction (left ventricular ejection fraction <35%) (56 vs. 30%; P=0.001). Patients with CHF were less likely to receive in-hospital β-blockers (74 vs. 86%; P=0.001) and a percutaneous coronary intervention (19 vs. 50%; P=0.001). Adjusted in-hospital mortality and cardiogenic shock were higher in the CHF group (odds ratio 4.43, 95% confidence interval 2.52-7.78; and odds ratio 3.51, 95% confidence interval 2.23-5.52), respectively. ACS patients with CHF in the Saudi Project for Assessment of Coronary Events were older, more likely to have more cardiac risk factors, and less likely to be treated with optimum medical treatment on admission. These findings were associated with higher incidence of their in-hospital adverse outcomes. More aggressive treatment is warranted to improve prognosis.
Joynt, Karen E.; Orav, E. John; Jha, Ashish K.
2012-01-01
Background Congestive Heart Failure (CHF) is common and costly, and despite pharmacologic and technical advances, outcomes remain suboptimal. Objective To examine whether hospitals that have more experience caring for patients with CHF provide better, more efficient care. Design We used national Medicare claims data from 2006–2007 to examine the relationship between hospitals’ case volume and quality, outcomes, and costs for patients with CHF. Setting 4,095 U.S. hospitals Patients Medicare fee-for-service patients with a primary discharge diagnosis of CHF Measurements Hospital Quality Alliance (HQA) CHF process measures, 30-day risk-adjusted mortality rates, 30-day risk-adjusted readmission rates, and costs per discharge. Results Hospitals in the lowest volume group had lower performance on HQA measures than medium- or high-volume hospitals (80.2% versus 87.0% versus 89.1%, p<0.001). Within the low volume group, being admitted to a hospital with a higher case volume was associated with lower mortality, lower readmission, and higher costs. For example, in the lowest volume group of hospitals, an increase of 10 cases of CHF was associated with 1% lower odds of mortality, 1% lower odds of readmissions and $22 higher costs per case. We found similar though smaller relationships between case volume and both mortality and costs in the medium and high-volume hospital cohorts. Limitations Our analysis was limited to Medicare patients 65 years of age or older; risk adjustment was performed using administrative data. Conclusions Experience with managing CHF, as measured by an institution’s volume, is associated with higher quality of care and better outcomes for patients, but at a higher cost. Understanding which practices employed by high-volume institutions account for these advantages can help improve quality of care and clinical outcomes for all CHF patients. PMID:21242366
Rossoni, Giuseppe; Manfredi, Barbara; Razzetti, Roberta; Civelli, Maurizio; Bongrani, Stefano; Berti, Ferruccio
2005-01-01
Pretreatment of anaesthetized guinea-pigs with either CHF 4226.01 (8-hydroxy-5-[(1R)-1-hydroxy-2-[N-[(1R)-2-(p-methoxyphenyl)-1-methylethyl]amino]ethyl] carbostyril hydrochloride), formoterol or budesonide reduced acetaldehyde (AcCHO)-evoked responses in the lungs with a rank order of potency CHF 4226.01 (ED50 values, from 1.88 to 3.31 pmol) > formoterol (ED50 values, from 3.03 to 5.51 pmol) ≫ budesonide (ED50 values, from 335 to 458 nmol). The duration of action of CHF 4226.01 in antagonizing the airway obstruction elicited by AcCHO was also substantially longer than formoterol (area under the curve) at 10 pmol, 763±58 and 480±34, respectively; P<0.01). Continuous infusion of a subthreshold dose of AcCHO enhanced the intratracheal pressure (ITP) increases caused by subsequent challenges with substance P (from 9.7±0.8 to 27.5±1.6 cm H2O as a peak, P<0.001). Pretreatment with either CHF 4226.01 or formoterol prevented the sensitizing effect of AcCHO on substance P responses (ED50 values, 2.85 and 6.11 pmol, respectively; P<0.01). The ED50 value of budesonide (396 nmol) in preventing AcCHO-evoked ITP increase was reduced when this glucocorticoid was combined with 0.1 pmol CHF 4226.01 (ED50 76 nmol; P<0.001). CHF 4226.01/budesonide was two-fold more effective (P<0.01) than the formoterol/budesonide combination. These results suggest that CHF 4226.01/budesonide, by optimizing each other's beneficial potential in the control of pulmonary changes caused by AcCHO in the guinea-pigs, may represent a new fixed combination in asthma. PMID:15655502
NASA Astrophysics Data System (ADS)
Coso, Dusan
The first part of the dissertation presents a study that implements micro and nano scale engineered surfaces for enhancement of evaporation and boiling phase change heat transfer in both capillary wick structures and pool boiling systems. Capillary wicking surfaces are integral components of heat pipes and vapor chamber thermal spreaders often used for thermal management of microelectronic devices. In addition, pool boiling systems can be encountered in immersion cooling systems which are becoming more commonly investigated for thermal management applications of microelectronic devices and even data centers. The latent heat associated with the change of state from liquid to vapor, and the small temperature differences required to drive this process yield great heat transfer characteristics. Additionally, since no external energy is required to drive the phase change process, these systems are great for portable devices and favorable for reduction of cost and energy consumption over alternate thermal management technologies. Most state of the art capillary wicks used in these devices are typically constructed from sintered copper media. These porous structures yield high surface areas of thin liquid film where evaporation occurs, thus promoting phase change heat transfer. However, thermal interfaces at particle point contacts formed during the sintering process and complex liquid/vapor flow within these wick structures yield high thermal and liquid flow resistances and limit the maximum heat flux they can dissipate. In capillary wicks the maximum heat flux is typically governed by the capillary or boiling limits and engineering surfaces that delay these limitations and yield structures with large surface areas of thin liquid film where phase change heat transfer is promoted is highly desired. In this study, biporous media consisting of microscale pin fins separated by microchannels are examined as candidate structures for the evaporator wick of a vapor chamber heat pipe. Smaller pores are used to generate high capillary suction, while larger microchannels are used to alleviate flow resistance. The heat transfer coefficient is found to depend on the area coverage of a liquid film with thickness on the order of a few microns near the meniscus of the triple phase contact line. We manipulate the area coverage and film thickness by varying the surface area-to-volume ratio through the use of microstructuring. In some samples, a transition from evaporative heat transfer to nucleate boiling is observed. While it is difficult to identify when the transition occurs, one can identify regimes where evaporation dominates over nucleate boiling and vice versa. Heat fluxes of 277.0 (+/- 9.7) W/cm2 can be dissipated by wicks with heaters of area 1 cm2, while heat fluxes up to 733.1 (+/- 103.4) W/cm2 can be dissipated by wicks with smaller heaters intended to simulate local hot-spots. In pool boiling systems that are encountered in immersion cooling applications, the heat transfer coefficient (HTC) is governed by the bubble nucleation site density and the agitation in the liquid/vapor flow these bubbles produce when they detach from the surface. The nucleation site density and release rate is usually determined by the surface morphology. Another important parameter in pool boiling systems is the maximum heat flux (CHF) that can safely be dissipated. In practice, this quantity is about two orders of magnitude smaller than limitations suggested by kinetic theory. For essentially infinite, smooth, well wetted surfaces, hydrodynamic instability theories capturing liquid/vapor interactions away from the heated surface have been successful in predicting CHF. On finite micro and nano structured surfaces where applying the hydrodynamic theory formulation is not easily justified, other effects may contribute to phase change heat transfer characteristics. Here, we also present a pool boiling study on biporous microstructured surfaces used in capillary wick experiments. Structures are manipulated by reduction of pore size to determine if increased capillary pressure can enhance rewetting from heater edges and delay CHF. A comparative study between the two experimental systems indicates that while the capillary limitation is significant in capillary wick experiments, for these well wetted microstructured surfaces used in pool boiling systems the hydrodynamic limitation defined based on heater size causes the occurrence of CHF. Other hierarchical nanowire surfaces containing periodic microscale cavities are investigated as well and are seen to yield a ˜2.4 fold increase in heat transfer coefficient characteristics while not compromising CHF compared to surfaces where cavities are not present. These studies indicate pathways for enhancement of heat transfer coefficient via implementing hierarchical structures, while no clear method in increasing CHF is determined for finite size surfaces of various morphologies. In the second part of this dissertation, solar energy storage is sought in 'phase change' of photochromic molecular systems: the storage of solar energy in the chemical bonds of photosensitive molecules (a photochemical reaction) and subsequent recovery of the energy in a back reaction in the form of heat, reversibly. These molecular systems are interesting alternatives to photovoltaic and solar thermal technologies which cannot satisfy the needs of load leveling, or for portable municipal heating applications. Typically made of organic compounds, these molecules have become known for rapid decomposition, short energy storage time scales and poor energy storing efficiencies. Thus, they have been abandoned as practical solar energy storage systems in the past several decades. On the other hand, organometallic molecular systems have not been extensively probed for these applications. Recent research has indicated that organometallic (fulvalene)diruthenium FvRu2 has demonstrated excellent energy storage characteristic and durability. Here, we report on a full cycle molecular solar thermal (MOST) microfluidic system based on a bis(1,1-dimethyltridecyl) substituted derivative of FvRu2 that allows for long term solar energy storage (110 J/g), and "on demand" energy release upon exposure to a catalyst. The microfluidic systems developed here are excellent for photoconversion characterization and scrutinizing potential catalysts and can be extended to studying many other molecular systems. The objective of the work presented here is to demonstrate that "on demand" solar energy storage and release in MOST systems is viable and motivate future research on other photochromic organometallic systems.
Steady-State Thermal-Hydraulics Analyses for the Conversion of the BR2 Reactor to LEU
DOE Office of Scientific and Technical Information (OSTI.GOV)
Licht, J. R.; Bergeron, A.; Dionne, B.
BR2 is a research reactor used for radioisotope production and materials testing. It’s a tank-in-pool type reactor cooled by light water and moderated by beryllium and light water. The reactor core consists of a beryllium moderator forming a matrix of 79 hexagonal prisms in a hyperboloid configuration; each having a central bore that can contain a variety of different components such as a fuel assembly, a control or regulating rod, an experimental device, or a beryllium or aluminum plug. Based on a series of tests, the BR2 operation is currently limited to a maximum allowable heat flux of 470 W/cmmore » 2 to ensure fuel plate integrity during steady-state operation and after a loss-of-flow/loss-of-pressure accident. A feasibility study for the conversion of the BR2 reactor from highly-enriched uranium (HEU) to low-enriched uranium (LEU) fuel was previously performed to verify it can operate safely at the same maximum nominal steady-state heat flux. An assessment was also performed to quantify the heat fluxes at which the onset of flow instability and critical heat flux occur for each fuel type. This document updates and expands these results for the current representative core configuration (assuming a fresh beryllium matrix) by evaluating the onset of nucleate boiling (ONB), onset of fully developed nucleate boiling (FDNB), onset of flow instability (OFI) and critical heat flux (CHF).« less
Samyshkin, Yevgeniy; Schlunegger, Michael; Haefliger, Susan; Ledderhose, Sabine; Radford, Matthew
2013-01-01
Objective Chronic obstructive pulmonary disease (COPD) represents a burden on patients and health systems. Roflumilast, an oral, selective phosphodiesterase-4-inhibitor reduces exacerbations and improves lung function in severe/very severe COPD patients with a history of exacerbations. This study aimed to estimate the lifetime cost and outcomes of roflumilast added-on to commonly used COPD regimens in Switzerland. Methods A Markov cohort model was developed to simulate COPD progression in patients with disease states of severe, very severe COPD, and death. The exacerbation rate was assumed to be two per year in severe COPD. COPD progression rates were drawn from the published literature. Efficacy was expressed as relative ratios of exacerbation rates associated with roflumilast, derived from a mixed-treatment comparison. A cost-effectiveness analysis was conducted for roflumilast added to long-acting muscarinic antagonists (LAMA), long-acting β2-agonist/ inhaled corticosteroids (LABA/ICS), and LAMA + LABA/ICS. The analysis was conducted from the Swiss payer perspective, with costs and outcomes discounted at 2.5% annually. Parameter uncertainties were explored in one-way and probabilistic sensitivity analyses. Results In each of the comparator regimens mean life expectancy was 9.28 years and quality-adjusted life years (QALYs) gained were 6.19. Mean estimated lifetime costs per patient in the comparator arms were CHF 83,364 (LAMA), CHF 88,161 (LABA/ICS), and CHF 95,564 (LAMA + LABA/ICS) respectively. Adding roflumilast resulted in a mean cost per patient per lifetime of CHF 86,754 (LAMA + roflumilast), CHF 91,470 (LABA/ICS + roflumilast), and CHF 99,364 (LAMA + LABA/ICS + roflumilast), respectively. Life-expectancy and quality-adjusted life-expectancy were 9.63 years and 6.47 QALYs (LAMA + roflumilast), 9.64 years and 6.48 QALYs (LABA/ICS + roflumilast), and 9.63 years and 6.47 QALYs (LAMA + LABA/ ICS + roflumilast). Incremental cost-effectiveness ratios were CHF 12,313, CHF 11,456, and CHF 13,671 per QALY when roflumilast was added to the three regimens. Conclusion Treatment with roflumilast is estimated to reduce the health and economic burden of COPD exacerbations and represent a cost-effective treatment option for patients with frequent exacerbations in Switzerland. PMID:23386787
Effect of diameter of metal nanowires on pool boiling heat transfer with FC-72
NASA Astrophysics Data System (ADS)
Kumar G., Udaya; S., Suresh; M. R., Thansekhar; Babu P., Dinesh
2017-11-01
Effect of varying diameter of metal nanowires on pool boiling heat transfer performance is presented in this study. Copper nanowires (CuNWs) of four different diameters (∼35 nm, ∼70 nm, ∼130 nm and ∼200 nm) were grown directly on copper specimen using template-based electrodeposition technique. Both critical heat flux (CHF) and boiling heat transfer coefficient (h) were found to be improved in surfaces with nanowires as compared to the bare copper surface. Moreover, both the parameters were found to increase with increasing diameter of the nanowires. The percentage increases observed in CHF for the samples with nanowires were 38.37%, 40.16%, 48.48% and 45.57% whereas the percentage increase in the heat transfer coefficient were 86.36%, 95.45%, 184.1% and 131.82% respectively as compared to the bare copper surface. Important reasons believed for this enhancement were improvement in micron scale cavity density and cavity size which arises as a result of the coagulation and grouping of nanowires during the drying process. In addition to this, superhydrophilic nature, capillary effect, and enhanced bubble dynamics parameters (bubble frequency, bubble departure diameter, and nucleation site density) were found to be the concurring mechanisms responsible for this enhancement in heat transfer performance. Qualitative bubble dynamics analysis was done for the surfaces involved and the visual observations are provided to support the results presented and discussed.
NASA Astrophysics Data System (ADS)
Li, Wenming; Qu, Xiaopeng; Alam, Tamanna; Yang, Fanghao; Chang, Wei; Khan, Jamil; Li, Chen
2017-01-01
In a microchannel system, a higher mass velocity can lead to enhanced flow boiling performances, but at a cost of two-phase pressure drop. It is highly desirable to achieve a high heat transfer rate and critical heat flux (CHF) exceeding 1 kW/cm2 without elevating the pressure drop, particularly, at a reduced mass velocity. In this study, we developed a microchannel configuration that enables more efficient utilization of the coolant through integrating multiple microscale nozzles connected to auxiliary channels as well as microscale reentry cavities on sidewalls of main microchannels. We achieved a CHF of 1016 W/cm2 with a 50% less mass velocity, i.e., 680 kg/m2s, compared to the two-nozzle configuration developed in our previous studies. Two primary enhancement mechanisms are: (a) the enhanced global liquid supply by four evenly distributed micronozzles, particularly near the outlet region and (b) the effective management of local dryout by the capillary flow-induced sustainable thin liquid film resulting from an array of microscale cavities. A significantly improved heat transfer coefficient of 131 kW/m2 K at a mass velocity of 680 kg/m2s is attributed to the enhanced nucleate boiling, the established capillary/thin film evaporation, and the induced advection from the present microchannel configuration. All these significant enhancements have been achieved with a ˜55% lower two-phase pressure drop.
Griffo, Raffaele; Spanevello, Antonio; Temporelli, Pier Luigi; Faggiano, Pompilio; Carones, Mauro; Magni, Giovanna; Ambrosino, Nicolino; Tavazzi, Luigi
2014-03-01
Chronic heart failure (CHF) and chronic obstructive pulmonary disease (COPD) are leading causes of morbidity and mortality worldwide. Through shared risk factors and pathophysiological mechanisms, CHF and COPD frequently coexist. The concurrent disease has important therapeutic implications and independently predicts worsened mortality, impaired functional status, and health service use. However, assessment of the comorbidity varies widely according to the population studied, diagnostic criteria and measurement tools applied. Both syndromes have been studied extensively but largely separately, mostly in the domain of the pulmonologist for COPD and in the domain of the cardiologist for CHF. The aim of the study is to evaluate in an Italian outpatients setting (10 cardiology and 10 pulmonology centers from the same institution) the prevalence, clinical profile and the routine diagnostic, functional and therapeutic work-up applied by cardiologists and pulmonologists in the presence/suspicion of concurrent disease in patients in a stable phase of their disease. For this purpose, CHF and COPU outpatients will be enrolled in a multicenter, nationwide, prospective observational study. Risk estimation of comorbidity will be based on suspected, documented or patient-reported diagnosis of COPD/CHF. In the absence of documented concurrent diagnosis, each specialist will describe the diagnostic, functional and therapeutic work-up applied. The design of the study focused on the diagnostic validation of the CHF-COPD comorbidity aims to provide relevant new information on the assessment of the coexistent condition in the cardiac and pulmonary outpatients setting and on specialty-related different diagnostic and therapeutic strategies of comorbidity utilized in real life clinical practice. The symptomatic and prognostic benefits resulting from a combined approach to CHF/COPD could outweigh those attainable by treating either condition alone.
Noyes, Katia; Corona, Ethan; Veazie, Peter; Dick, Andrew W.; Zhao, Hongwei; Moss, Arthur J.
2015-01-01
Background While implantable cardioverter-defibrillators (ICDs) improve survival, their benefit in terms of health-related quality of life (HRQOL) is negligible. Objective To examine how shocks and congestive heart failure (CHF) mediate the effect of ICDs on HRQOL. Methods The US patients from the MADIT-II (Multicenter Automatic Defibrillator Trial-II) trial (n = 983) were randomized to receive an ICD or medical treatment only. HRQOL was assessed using the Health Utility Index 3 at baseline and 3, 12, 24, and 36 months following randomization. Logistic regressions were used to test for the effect of ICDs on the CHF indicator, and linear regressions were used to examine the effect of ICD shocks and CHF on HRQOL in living patients. We used a Monte Carlo simulation and a parametric Weibull distribution survival model to test for the effect of selective attrition. Observations were clustered by patients and robust standard errors (RSEs) were used to control for the non-independence of multiple observations provided by the same patient. Results Patients in the ICD arm had 41% higher odds of experiencing CHF since their last assessment compared with those in the control arm (RSE = 0.19, p = 0.01). Developing CHF reduced HRQOL at the subsequent visit by 0.07 (p < 0.01). Having ICD shocks reduced overall HRQOL by 0.04 (p = 0.04) at the subsequent assessment. The negative effect of ICD firing on HRQOL was an order of magnitude greater than the effect of CHF. Conclusions A higher prevalence of CHF and shocks among patients with ICDs and their negative effect on HRQOL may partially explain the lack of HRQOL benefit of ICD therapy. PMID:19929037
Koba, Satoshi; Hisatome, Ichiro; Watanabe, Tatsuo
2014-09-01
Sympathoexcitation elicited by central command, a parallel activation of the motor and autonomic neural circuits in the brain, has been shown to become exaggerated in chronic heart failure (CHF). The present study tested the hypotheses that oxidative stress in the medulla in CHF plays a role in exaggerating central command-elicited sympathoexcitation, and that exercise training in CHF suppresses central command-elicited sympathoexcitation through its antioxidant effects in the medulla. In decerebrate rats, central command was activated by electrically stimulating the mesencephalic locomotor region (MLR) after neuromuscular blockade. The MLR stimulation at a current intensity greater than locomotion threshold in rats with CHF after myocardial infarction (MI) evoked larger (P < 0.05) increases in renal sympathetic nerve activity and arterial pressure than in sham-operated healthy rats (Sham) and rats with CHF that had completed longterm (8–12 weeks) exercise training (MI + TR). In the Sham and MI + TR rats, bilateral microinjection of a superoxide dismutase (SOD) mimetic Tempol into the rostral ventrolateral medulla (RVLM) had no effects on MLR stimulation-elicited responses. By contrast, in MI rats, Tempol treatment significantly reduced MLR stimulation-elicited responses. In a subset of MI rats, treatment with Tiron, another SOD mimetic, within the RVLM also reduced responses. Superoxide generation in the RVLM, as evaluated by dihydroethidium staining, was enhanced in MI rats compared with that in Sham and MI + TR rats. Collectively, these results support the study hypotheses. We suggest that oxidative stress in the medulla in CHF mediates central command dysfunction, and that exercise training in CHF is capable of normalizing central command dysfunction through its antioxidant effects in the medulla.
Chen, Pingan; Li, Shaonan; Lei, Xiaoming; Liu, Zhen; Wu, Daihong; Luo, Yi; Xu, Dingli
2015-08-01
In chronic heart failure (CHF) patients with type 2 diabetes mellitus (T2DM), the role of thyroid hormone (TH) in predicting CHF severity and prognosis is unclear. The authors therefore investigated the role of TH in predicting CHF severity and prognosis in these specific patients. A total of 224 CHF patients (114 with T2DM) over a mean follow-up time of 6.56 ± 0.18 months were studied. TH, N-terminal pro-B-type natriuretic peptide (NT-proBNP) and other parameters were measured. Free triiodothyronine (FT3) levels were lower in the T2DM group compared with the nondiabetes group (P = 0.026) and higher in the New York Heart Association (NYHA) I group than in the NYHA III and IV groups (both P < 0.05). Compared with the low NT-proBNP group, the high NT-proBNP group had lower FT3 levels (P < 0.01). NT-proBNP correlated with NYHA classes (r = 0.541, P < 0.001), and inversely correlated with left ventricular ejection fraction (r = -0.431, P < 0.001) and FT3 levels (r = -0.335, P < 0.001). In multiple linear regression analysis, NT-proBNP was significantly correlated with NYHA classes (P < 0.001), left ventricular ejection fraction (P < 0.001) and FT3 (P = 0.004). Kaplan-Meier curves showed that the low FT3 group had an increased rate of short-term adverse outcomes of CHF (log rank, χ = 9.794, P = 0.002). FT3 levels are associated with the severity of CHF and seem to reflect short-term outcomes in CHF patients with T2DM.
Yamanaka, Shinsuke; Takahashi, Yoshimi; Fujita, Hiroshi; Yamaguchi, Nobuhiro; Onoue, Noriko; Ishizuka, Takeshi; Shinozaki, Tsuyoshi; Kohzuki, Masahiro
2016-01-01
Early detection and intervention for dysphagia is important in patients with congestive heart failure (CHF). However, previous studies have focused on how many patients with dysphagia develop CHF. Studies focusing on the comorbidity of dysphagia in patients with CHF are rare. Additionally, risk factors for dysphagia in patients with CHF are unclear. Thus, the aim of this study was to clarify risk factors for dysphagia in patients with acute exacerbation of CHF. A total of 105 patients, who were admitted with acute exacerbation of CHF, were enrolled. Clinical interviews, blood chemistry analysis, electrocardiography, echocardiography, Mini-Mental State Examination (MMSE), exercise tolerance tests, phonatory function tests, and evaluation of activities of daily living (ADL) and nutrition were conducted on admission. After attending physicians permitted the drinking of water, swallowing screening tests were performed. Patients were divided into a dysphagia group (DG) or a non-dysphagia group (non-DG) based on Functional Oral Intake Scale level. Among the 105 patients, 38 had dysphagia. A greater number of patients had history of aspiration pneumonia and dementia, and there was a higher age, N-terminal pro-B-type natriuretic peptide level in the DG compared with the non-DG. MMSE scores, exercise tolerance, phonatory function, status of ADL, nutrition, albumin, and transthyretin were lower in the DG compared with the non-DG. In multivariate analysis, after adjusting for age and sex, MMSE, BI score, and transthyretin was independently associated with dysphagia. Comorbidity of dysphagia was 36.1% in patients with acute exacerbation of CHF, and cognitive dysfunction and malnutrition may be an independent predictor of dysphagia. PMID:27898735
Yokota, Junichi; Ogawa, Yoshiko; Yamanaka, Shinsuke; Takahashi, Yoshimi; Fujita, Hiroshi; Yamaguchi, Nobuhiro; Onoue, Noriko; Ishizuka, Takeshi; Shinozaki, Tsuyoshi; Kohzuki, Masahiro
2016-01-01
Early detection and intervention for dysphagia is important in patients with congestive heart failure (CHF). However, previous studies have focused on how many patients with dysphagia develop CHF. Studies focusing on the comorbidity of dysphagia in patients with CHF are rare. Additionally, risk factors for dysphagia in patients with CHF are unclear. Thus, the aim of this study was to clarify risk factors for dysphagia in patients with acute exacerbation of CHF. A total of 105 patients, who were admitted with acute exacerbation of CHF, were enrolled. Clinical interviews, blood chemistry analysis, electrocardiography, echocardiography, Mini-Mental State Examination (MMSE), exercise tolerance tests, phonatory function tests, and evaluation of activities of daily living (ADL) and nutrition were conducted on admission. After attending physicians permitted the drinking of water, swallowing screening tests were performed. Patients were divided into a dysphagia group (DG) or a non-dysphagia group (non-DG) based on Functional Oral Intake Scale level. Among the 105 patients, 38 had dysphagia. A greater number of patients had history of aspiration pneumonia and dementia, and there was a higher age, N-terminal pro-B-type natriuretic peptide level in the DG compared with the non-DG. MMSE scores, exercise tolerance, phonatory function, status of ADL, nutrition, albumin, and transthyretin were lower in the DG compared with the non-DG. In multivariate analysis, after adjusting for age and sex, MMSE, BI score, and transthyretin was independently associated with dysphagia. Comorbidity of dysphagia was 36.1% in patients with acute exacerbation of CHF, and cognitive dysfunction and malnutrition may be an independent predictor of dysphagia.
Adlbrecht, Christopher; Hülsmann, Martin; Strunk, Guido; Berger, Rudolf; Mörtl, Deddo; Struck, Joachim; Morgenthaler, Nils G; Bergmann, Andreas; Jakowitsch, Johannes; Maurer, Gerald; Lang, Irene M; Pacher, Richard
2009-04-01
The identification of chronic heart failure (CHF) patients at high risk of adverse outcome remains a challenge. New peptides are emerging that may give additional information. In CHF patients, endothelin (ET) levels predict mortality risk. Adrenomedullin has been shown to predict mortality in ischaemic heart failure, but not in unselected or non-ischaemic CHF patients. Moreover, ADM and ET have never been assessed in one model. The aim of the present study was to assess the prognostic value of midregional-pro-adrenomedullin (MR-proADM) and C-terminal-pro-endothelin-1 (CT-proET-1) in outpatients with CHF. We measured plasma MR-proADM and CT-proET-1 levels in 786 consecutive CHF outpatients and compared them with B-type natriuretic peptide (BNP) levels. At 24-month follow-up, 233 patients had died. A stepwise forward Cox regression model with age, sex, estimated glomerular filtration rate, NYHA > II, left ventricular ejection fraction (LVEF), MR-proADM, CT-proET-1, and BNP as possible predictors revealed that MR-proADM levels [hazard ratio (HR) = 1.77, P < 0.001] in addition to age (HR = 1.02, P = 0.004), ejection fraction (HR = 0.98, P = 0.004), and NYHA > II (HR = 1.86, P < 0.001) were predictors of death at 24 months. When the analysis was repeated dependent on NYHA-stage, MR-proADM (HR = 2.12, P < 0.001) and LVEF (HR = 0.96, P = 0.006) were significant markers, but only in patients with mild/moderate CHF. Our data suggest that MR-proADM may be an important prognostic humoral marker, especially in mild/moderately symptomatic and non-ischaemic CHF patients.
Landmesser, Ulf; Spiekermann, Stephan; Dikalov, Sergey; Tatge, Helma; Wilke, Ragna; Kohler, Christoph; Harrison, David G; Hornig, Burkhard; Drexler, Helmut
2002-12-10
Impaired flow-dependent, endothelium-mediated vasodilation (FDD) in patients with chronic heart failure (CHF) results, at least in part, from accelerated degradation of nitric oxide by oxygen radicals. The mechanisms leading to increased vascular radical formation, however, remain unclear. Therefore, we determined endothelium-bound activities of extracellular superoxide dismutase (ecSOD), a major vascular antioxidant enzyme, and xanthine-oxidase, a potent radical producing enzyme, and their relation to FDD in patients with CHF. ecSOD and xanthine-oxidase activities, released from endothelium into plasma by heparin bolus injection, were determined in 14 patients with CHF and 10 control subjects. FDD of the radial artery was measured using high-resolution ultrasound and was assessed before and after administration of the antioxidant vitamin C (25 mg/min; IA). In patients with CHF, endothelium-bound ecSOD activity was substantially reduced (5.0+/-0.7 versus 14.4+/-2.6 U x mL(-1) x min(-1); P<0.01) and closely related to FDD (r=0.61). Endothelium-bound xanthine-oxidase activity was increased by >200% (38+/-10 versus 12+/-4 nmol O2*- x microL(-1); P<0.05) and inversely related to FDD (r=-0.35) in patients with CHF. In patients with low ecSOD and high xanthine-oxidase activity, a greater benefit of vitamin C on FDD was observed, ie, the portion of FDD inhibited by radicals correlated negatively with ecSOD (r=-0.71) but positively with xanthine-oxidase (r=0.75). These results demonstrate that both increased xanthine-oxidase and reduced ecSOD activity are closely associated with increased vascular oxidative stress in patients with CHF. This loss of vascular oxidative balance likely represents a novel mechanism contributing to endothelial dysfunction in CHF.
The PDE4 inhibitor CHF-6001 and LAMAs inhibit bronchoconstriction-induced remodeling in lung slices.
Kistemaker, Loes E M; Oenema, Tjitske A; Baarsma, Hoeke A; Bos, I Sophie T; Schmidt, Martina; Facchinetti, Fabrizio; Civelli, Maurizio; Villetti, Gino; Gosens, Reinoud
2017-09-01
Combination therapy of PDE4 inhibitors and anticholinergics induces bronchoprotection in COPD. Mechanical forces that arise during bronchoconstriction may contribute to airway remodeling. Therefore, we investigated the impact of PDE4 inhibitors and anticholinergics on bronchoconstriction-induced remodeling. Because of the different mechanism of action of PDE4 inhibitors and anticholinergics, we hypothesized functional interactions of these two drug classes. Guinea pig precision-cut lung slices were preincubated with the PDE4 inhibitors CHF-6001 or roflumilast and/or the anticholinergics tiotropium or glycopyorrolate, followed by stimulation with methacholine (10 μM) or TGF-β 1 (2 ng/ml) for 48 h. The inhibitory effects on airway smooth muscle remodeling, airway contraction, and TGF-β release were investigated. Methacholine-induced protein expression of smooth muscle-myosin was fully inhibited by CHF-6001 (0.3-100 nM), whereas roflumilast (1 µM) had smaller effects. Tiotropium and glycopyrrolate fully inhibited methacholine-induced airway remodeling (0.1-30 nM). The combination of CHF-6001 and tiotropium or glycopyrrolate, in concentrations partially effective by themselves, fully inhibited methacholine-induced remodeling in combination. CHF-6001 did not affect airway closure and had limited effects on TGF-β 1 -induced remodeling, but rather, it inhibited methacholine-induced TGF-β release. The PDE4 inhibitor CHF-6001, and to a lesser extent roflumilast, and the LAMAs tiotropium and glycopyrrolate inhibit bronchoconstriction-induced remodeling. The combination of CHF-6001 and anticholinergics was more effective than the individual compounds. This cooperativity might be explained by the distinct mechanisms of action inhibiting TGF-β release and bronchoconstriction. Copyright © 2017 the American Physiological Society.
Liu, Hao; Shi, Hong; Yu, Jinming; Chen, Fang; Jiang, Qingwu; Hu, Dayi
2011-08-01
Obesity and decreased kidney function have been shown to be prevalent in Western patients with heart failure; however, whether this phenomenon exists in Chinese patients with chronic heart failure (CHF) is not known. One thousand and nine patients with CHF from the China Heart Survey were assessed. The prevalence of chronic kidney disease (CKD) was 34.2%, and there was a stepwise increase in the prevalence of CKD with New York Heart Association (NYHA) classes (P < 0.001). Moreover, patients with CKD had a significantly elevated risk for developing severe extent of CHF (OR = 1.69, 95% CI: 1.27-2.24, P < 0.001). The prevalence of obesity and central obesity was 35.7% and 62.5%, respectively. Notably, there was a downward trend in the prevalence of obesity with advanced NYHA classes (trend test, P = 0.003). Multivariate analysis further supported the finding that obesity, but not central obesity, was inversely associated with the extent of CHF (OR = 0.72, 95% CI: 0.55-0.94, P = 0.017). Renal dysfunction is common in Chinese patients with CHF and is independently associated with advanced NYHA classes. Obesity was inversely associated with the extent of CHF, which further supports the notion that obesity confers improved prognosis in patients with heart failure.
Self Managing Heart Failure in Remote Australia - Translating Concepts into Clinical Practice
Iyngkaran, Pupalan; Toukhsati, Samia R.; Harris, Melanie; Connors, Christine; Kangaharan, Nadarajan; Ilton, Marcus; Nagel, Tricia; Moser, Debra K.; Battersby, Malcolm
2016-01-01
Congestive heart failure (CHF) is an ambulatory health care condition characterized by episodes of decompensation and is usually without cure. It is a leading cause for morbidity and mortality and the lead cause for hospital admissions in older patients in the developed world. The long-term requirement for medical care and pharmaceuticals contributes to significant health care costs. CHF management follows a hierarchy from physician prescription to allied health, predominately nurse-led, delivery of care. Health services are easier to access in urban compared to rural settings. The differentials for more specialized services could be even greater. Remote Australia is thus faced with unique challenges in delivering CHF best practice. Chronic disease self-management programs (CDSMP) were designed to increase patient participation in their health and alleviate stress on health systems. There have been CDSMP successes with some diseases, although challenges still exist for CHF. These challenges are amplified in remote Australia due to geographic and demographic factors, increased burden of disease, and higher incidence of comorbidities. In this review we explore CDSMP for CHF and the challenges for our region. PMID:27397492
The Indian Consensus Document on cardiac biomarker.
Satyamurthy, I; Dalal, Jamshed J; Sawhney, J P S; Mohan, J C; Chogle, Shubha A; Desai, Nagaraj; Sathe, Shireesh P; Maisel, Alan S
2014-01-01
Despite recent advances, the diagnosis and management of heart failure evades the clinicians. The etiology of congestive heart failure (CHF) in the Indian scenario comprises of coronary artery disease, diabetes mellitus and hypertension. With better insights into the pathophysiology of CHF, biomarkers have evolved rapidly and received diagnostic and prognostic value. In CHF biomarkers prove as measures of the extent of pathophysiological derangement; examples include biomarkers of myocyte necrosis, myocardial remodeling, neurohormonal activation, etc. In CHF biomarkers act as indicators for the presence, degree of severity and prognosis of the disease, they may be employed in combination with the present conventional clinical assessments. These make the biomarkers feasible options against the present expensive measurements and may provide clinical benefits. Copyright © 2014 Cardiological Society of India. Published by Elsevier B.V. All rights reserved.
Heart Failure in Minority Populations - Impediments to Optimal Treatment in Australian Aborigines
Iyngkaran, Pupalan; Kangaharan, Nadarajan; Zimmet, Hendrik; Arstall, Margaret; Minson, Rob; Thomas, Merlin C.; Bergin, Peter; Atherton, John; MacDonald, Peter; Hare, David L.; Horowitz, John D.; Ilton, Marcus
2016-01-01
Chronic heart failure (CHF) among Aboriginal/Indigenous Australians is endemic. There are also grave concerns for outcomes once acquired. This point is compounded by a lack of prospective and objective studies to plan care. To capture the essence of the presented topic it is essential to broadly understand Indigenous health. Key words such as ‘worsening’, ‘gaps’, ‘need to do more’, ‘poorly studied’, or ‘future studies should inform’ occur frequently in contrast to CHF research for almost all other groups. This narrative styled opinion piece attempts to discuss future directions for CHF care for Indigenous Australians. We provide a synopsis of the problem, highlight the treatment gaps, and define the impediments that present hurdles in optimising CHF care for Indigenous Australians. PMID:27280307
NASA Astrophysics Data System (ADS)
Metzler, Dominik; Li, Chen; Engelmann, Sebastian; Bruce, Robert L.; Joseph, Eric A.; Oehrlein, Gottlieb S.
2017-02-01
With the increasing interest in establishing directional etching methods capable of atomic scale resolution for fabricating highly scaled electronic devices, the need for development and characterization of atomic layer etching processes, or generally etch processes with atomic layer precision, is growing. In this work, a flux-controlled cyclic plasma process is used for etching of SiO2 and Si at the Angstrom-level. This is based on steady-state Ar plasma, with periodic, precise injection of a fluorocarbon (FC) precursor (C4F8 and CHF3) and synchronized, plasma-based Ar+ ion bombardment [D. Metzler et al., J. Vac. Sci. Technol., A 32, 020603 (2014) and D. Metzler et al., J. Vac. Sci. Technol., A 34, 01B101 (2016)]. For low energy Ar+ ion bombardment conditions, physical sputter rates are minimized, whereas material can be etched when FC reactants are present at the surface. This cyclic approach offers a large parameter space for process optimization. Etch depth per cycle, removal rates, and self-limitation of removal, along with material dependence of these aspects, were examined as a function of FC surface coverage, ion energy, and etch step length using in situ real time ellipsometry. The deposited FC thickness per cycle is found to have a strong impact on etch depth per cycle of SiO2 and Si but is limited with regard to control over material etching selectivity. Ion energy over the 20-30 eV range strongly impacts material selectivity. The choice of precursor can have a significant impact on the surface chemistry and chemically enhanced etching. CHF3 has a lower FC deposition yield for both SiO2 and Si and also exhibits a strong substrate dependence of FC deposition yield, in contrast to C4F8. The thickness of deposited FC layers using CHF3 is found to be greater for Si than for SiO2. X-ray photoelectron spectroscopy was used to study surface chemistry. When thicker FC films of 11 Å are employed, strong changes of FC film chemistry during a cycle are seen whereas the chemical state of the substrate varies much less. On the other hand, for FC film deposition of 5 Å for each cycle, strong substrate surface chemical changes are seen during an etching cycle. The nature of this cyclic etching with periodic deposition of thin FC films differs significantly from conventional etching with steady-state FC layers since surface conditions change strongly throughout each cycle.
Sidorov, Jaan; Shull, Robert D; Girolami, Sabrina; Mensch, Debra
2003-01-01
While disease management has been described as an important strategy for the care of patients with congestive heart failure (CHF) in the managed care setting, little is known about the impact of this approach on overall health-related quality of life. In this study the Short Form 36 (SF-36) was administered to all patients entering CHF disease management at the time of program entry and at 1 year following entry. Scores on the eight subscales and the two composite scales were calculated and compared before and after. Patients were enrolled from a mixed-model health maintenance organization (HMO) with 34,740 Medicare + Choice enrollees residing in 38 counties in central and northeastern Pennsylvania. Two hundred sixty-eight continuously enrolled patients in an HMO-sponsored CHF disease state management program with completed baseline and follow-up SF-36 surveys were sampled. All patients entered into disease management received primary care based, nurse-directed education about CHF self-management including instruction on etiology of CHF, the importance of medication compliance, home care services if indicated, monitoring weight gain, increased understanding of the warning signs of worsening CHF, and coaching on strategies to contact a physician in a timely manner when CHF worsens. Nurses also facilitated for CHF guidelines among primary care physicians, including the need to obtain a baseline assessment of cardiac function, prescribe angiotensin I-converting enzyme (ACE) inhibitors and beta blockers when appropriate, and initiated appropriate specialist referral. Compared with enrollees who did not complete a pair of SF-36 surveys, the 268 respondents were younger and had a significantly higher rate of cardiac imaging as well as use of ACE inhibitors and beta blocker medications. Analysis of the SF-36 data revealed that three of the eight (Role Physical, General Health Perceptions, and Role Emotional) subscales increased in a statistically significant manner, as did the Mental Health Composite Score. No statistically significant declines in SF-36 scores were observed. Despite limitations to our study, we found disease management for patients with CHF can be associated with significant improvements in quality of life as measured by the SF-36. Compared with nonrespondents, respondents had a higher prevalence of cardiac imaging, ACE inhibitor use, and beta blocker medication use. Our findings are also limited by a lack of a control group with the possibility that the improvements we observed were unrelated to the disease management intervention. However, our findings and success with the use of this tool indicate the SF-36 can be an important part of the ongoing assessment of patients in a disease management program for CHF.
Inflammatory mediators in chronic heart failure in North India.
Fedacko, Jan; Singh, Ram B; Gupta, Aditya; Hristova, Krasimira; Toda, Eri; Kumar, Adarsh; Saxena, Manoj; Baby, Anjum; Singh, Ranjana; Toru, Takahashi; Wilson, Douglas W
2014-08-01
Recent evidence shows that pro-inflammatory cytokines may be important in the assessment of severity and prognosis in congestive heart failure (CHF). In the present study, we examine the association of cytokines with causes, grade and prognosis of CHF patients. Of 127 patients with CHF, 11 were excluded and the remaining 116 patients with different aetiologies of CHF, and 250 age- and sex-matched control subjects, were evaluated in this case study. Severity of disease based on the New York Heart Association (NYHA) standards, fell within functional classes II to IV. The diagnosis of HF was based on clinical manifestations as well as on echocardiographic heart enlargement. Cytokines were measured by chemiluminescence. Causes of death were assessed based on death certificates. Multivariate logistic regression analysis was used to determine the risk factors of heart failure. Echocardiographic ejection fraction was 39.1 +/- 8.2% (mean +/- SD) in the study group indicating class II-IV heart failure. Laboratory data showed increase in biomarkers of oxidative stress, among HF patients compared to healthy subjects. Pro-inflammatory cytokines; IL-6 and TNF-alpha were significantly higher among HF patients compared to healthy subjects. TNF-alpha and IL-6, showed significant increase among patients with CHF due to ischaemic heart disease and cardiomyopathy compared to levels among CHF patients with valvular heart disease and hypertensive heart diseases. The levels of the cytokines were significantly higher among patients with class III and IV heart failure and those who died, compared to patients with class II heart failure. Multivariate logistic regression analysis revealed that CAD, cardiomyopathy, and IL-6 were strongly associated--and low ejection fraction and TNF-alpha--weakly associated with HF. Of 116 patients, 20 (17.2%) died during a follow-up of two years, and the deaths were mainly among NYHA class III and IV patients in whom the cause of CHF was CAD (10.9%) and cardiomyopathy (6.9%) which had greater levels of cytokines. The findings indicated that pro-inflammatory cytokines may be important indicators of causes, severity of CHF and prognosis among these patients.
Kapologwe, Ntuli A; Kagaruki, Gibson B; Kalolo, Albino; Ally, Mariam; Shao, Amani; Meshack, Manoris; Stoermer, Manfred; Briet, Amena; Wiedenmayer, Karin; Hoffman, Axel
2017-04-27
Introduction of a health insurance scheme is one of the ways to enhance access to health care services and to protect individuals from catastrophic health expenditures. Little is known on the influence of socio-demographic and social marketing strategies on enrollment and re-enrollment in the Community Health Fund/Tiba Kwa Kadi (CHF/TIKA) in Tanzania. This cross-sectional study employed quantitative methods for data collection between November 2014 and March 2015 in Singida and Shinyanga regions. Relationship between variables was obtained through Chi-square test and multivariate logistic regression. We recruited 496 participants in the study. Majority (92.7%) of participants consented to participate, with 229 (49.8%) and 231 (50.2%) members and non members of CHF/TIKA respectively. Majority (90.9%) were aware of CHF/TIKA. Majority of CHF/TIKA members and non-members (90% and 68.3% respectively) reported health facility-based sensitization as the most common social marketing approach employed to market the CHF/TIKA. The most popular marketing strategies in the country including traditional dances, football games, radio, television, news papers, and mosques/church were reported by few CHF and non CHF members. Multivariate Logistic regression models revealed no significant association between social marketing strategies and enrollment, but only socio-demographics; including marital status (AOR = 2.0, 95% CI 1.1-3.8) and family size (household with ≥ 6 members) (AOR = 1.5, 95% CI 1.0-2.5), were significant factors associated with enrollment/re-enrollment rate. This study indicated that low level of utilization of available social marketing strategies and socio-demographic factors are the barriers for attracting members to join the schemes. There is a need for applying various social marketing strategies and considering different facilitating and impending socio-demographic factors for the growth and sustainability of the scheme as we move towards universal health coverage.
Arzilli, Chiara; Aimo, Alberto; Vergaro, Giuseppe; Ripoli, Andrea; Senni, Michele; Emdin, Michele; Passino, Claudio
2018-05-01
Background The Seattle heart failure model or the cardiac and comorbid conditions (3C-HF) scores may help define patient risk in heart failure. Direct comparisons between them or versus N-terminal fraction of pro-B-type natriuretic peptide (NT-proBNP) have never been performed. Methods Data from consecutive patients with stable systolic heart failure and 3C-HF data were examined. A subgroup of patients had the Seattle heart failure model data available. The endpoints were one year all-cause or cardiovascular death. Results The population included 2023 patients, aged 68 ± 12 years, 75% were men. At the one year time-point, 198 deaths were recorded (10%), 124 of them (63%) from cardiovascular causes. While areas under the curve were not significantly different, NT-proBNP displayed better reclassification capability than the 3C-HF score for the prediction of one year all-cause and cardiovascular death. Adding NT-proBNP to the 3C-HF score resulted in a significant improvement in risk prediction. Among patients with Seattle heart failure model data available ( n = 798), the area under the curve values for all-cause and cardiovascular death were similar for the Seattle heart failure model score (0.790 and 0.820), NT-proBNP (0.783 and 0.803), and the 3C-HF score (0.770 and 0.800). The combination of the 3C-HF score and NT-proBNP displayed a similar prognostic performance to the Seattle heart failure model score for both endpoints. Adding NT-proBNP to the Seattle heart failure model score performed better than the Seattle heart failure model alone in terms of reclassification, but not discrimination. Conclusions Among systolic heart failure patients, NT-proBNP levels had better reclassification capability for all-cause and cardiovascular death than the 3C-HF score. The inclusion of NT-proBNP to the 3C-HF and Seattle heart failure model score resulted in significantly better risk stratification.
An Automated Approach for Ranking Journals to Help in Clinician Decision Support
Jonnalagadda, Siddhartha R.; Moosavinasab, Soheil; Nath, Chinmoy; Li, Dingcheng; Chute, Christopher G.; Liu, Hongfang
2014-01-01
Point of care access to knowledge from full text journal articles supports decision-making and decreases medical errors. However, it is an overwhelming task to search through full text journal articles and find quality information needed by clinicians. We developed a method to rate journals for a given clinical topic, Congestive Heart Failure (CHF). Our method enables filtering of journals and ranking of journal articles based on source journal in relation to CHF. We also obtained a journal priority score, which automatically rates any journal based on its importance to CHF. Comparing our ranking with data gathered by surveying 169 cardiologists, who publish on CHF, our best Multiple Linear Regression model showed a correlation of 0.880, based on five-fold cross validation. Our ranking system can be extended to other clinical topics. PMID:25954382
Munasinghe, Pradeep Chaminda; Khanal, Samir Kumar
2012-10-01
In this study, the volumetric mass transfer coefficients (Ka) for CO were examined in a composite hollow fiber (CHF) membrane bioreactor. The mass transfer experiments were conducted at various inlet gas pressures (from 5 to 30 psig (34.5-206.8 kPa(g))) and recirculation flow rates (300, 600, 900, 1200 and 1500 mL/min) through CHF module. The highest Ka value of 946.6 1/h was observed at a recirculation rate of 1500 mL/min and at an inlet gas pressure of 30 psig(206.8 kPa(g)). The findings of this study confirm that the use of CHF membranes is effective and improves the efficiency CO mass transfer into the aqueous phase. Copyright © 2012 Elsevier Ltd. All rights reserved.
B-type natriuretic peptides. A diagnostic breakthrough in heart failure.
McCullough, P A
2003-04-01
B-type natriuretic peptide (BNP) is a neurohormone synthesized in the cardiac ventricles, which is released as N-terminal pro-brain natriuretic peptide (NT-proBNP) and then enzymatically cleaved in to the NT fragment and the immunoreactive BNP. Both tests have been used to identify patients with congestive heart failure (CHF). Important considerations for these tests include their half-lives in plasma, dependence on renal function for clearance, and the interpretation of their units of measure. In general, a BNP level below 100 pg/mL has strong negative predictive value in the assessment of patients with dyspnea caused by a disorder other than CHF. In addition, BNP levels can be used to gauge the effect of short-term treatment of acutely decompensated heart failure, and the peptide has been shown to be a reliable independent predictor of sudden cardiac death. In the absence of renal dysfunction NT-proBNP has also been shown to be an independent predictor of sudden death in CHF patients. Because both a large area of myonecrosis or concomitant left ventricular failure are related to prognosis in acute coronary syndromes, B-type natriuretic peptides have also been linked to outcomes in this condition. This article describes the physiology and timing of release of B-type natriuretic peptides and the rationale for their use in the following settings: 1) evaluation of decompensated CHF, 2) screening for chronic CHF, 3) prognosis of CHF and sudden death, and 4) prognosis in acute coronary syndromes with inferred left ventricular dysfunction.
Kane, P M; Murtagh, F E M; Ryan, K; Mahon, N G; McAdam, B; McQuillan, R; Ellis-Smith, C; Tracey, C; Howley, C; Raleigh, C; O'Gara, G; Higginson, I J; Daveson, B A
2015-11-01
Patient-centred care (PCC) is recommended in policy documents for chronic heart failure (CHF) service provision, yet it lacks an agreed definition. A systematic review was conducted to identify PCC interventions in CHF and to describe the PCC domains and outcomes. Medline, Embase, CINAHL, PsycINFO, ASSIA, the Cochrane database, clinicaltrials.gov, key journals and citations were searched for original studies on patients with CHF staged II-IV using the New York Heart Association (NYHA) classification. Included interventions actively supported patients to play informed, active roles in decision-making about their goals of care. Search terms included 'patient-centred care', 'quality of life' and 'shared decision making'. Of 13,944 screened citations, 15 articles regarding 10 studies were included involving 2540 CHF patients. Three studies were randomised controlled trials, and seven were non-randomised studies. PCC interventions focused on collaborative goal setting between patients and healthcare professionals regarding immediate clinical choices and future care. Core domains included healthcare professional-patient collaboration, identification of patient preferences, patient-identified goals and patient motivation. While the strength of evidence is poor, PCC has been shown to reduce symptom burden, improve health-related quality of life, reduce readmission rates and enhance patient engagement for patients with CHF. There is a small but growing body of evidence, which demonstrates the benefits of a PCC approach to care for CHF patients. Research is needed to identify the key components of effective PCC interventions before being able to deliver on policy recommendations.
[Effects of trimetazidine on serum oxygen free radicals in congestive heart failure].
Ma, Qi-lin; Xie, Yong; Zhang, Sai-dan
2002-12-28
To investigate the level of serum superoxide dismutase (SOD) and maiondialdehyde (MDA) and left ventricular systolic function in congestive heart failure (CHF) and to evaluate the influence of trimetazidine on them. Serum SOD and MDA were measured in 50 patients with heart function from grade two to four and 15 normal subjects. All the persons underwent echocardiography to determine the left ventricular end-systolic volume index (LVESVI) and the left ventricular ejection fraction (EF). The patients with CHF were randomly treated with trimetazidine plus routine therapy (n = 25) or routine therapy only (n = 25) for 8 weeks with evaluations made before and after the treatment. The SOD level and EF in the patients with CHF significantly decreased and the MDA level and LVESVI in those patients significantly increased compared with the normal subjects (P < 0.05); the severer the CHF, the greater the changes. After the treatment, the SOD level and EF increased significantly and MDA and LVESVI decreased significantly (P < 0.01) in both the trimetazidine and the conventional groups. And these changes were more obvious in the trimetazidine group than in the conventional group(P < 0.01). Oxygen free radicals play an important role in the pathophysiologic changes of CHF. The level of serum SOD and MDA can indicate the degree of CHF. Trimetazidine not only increases the level of SOD and decreases the level of MDA, but also improves the left ventricular systolic function.
Influenza infection and heart failure-vaccination may change heart failure prognosis?
Kadoglou, Nikolaos P E; Bracke, Frank; Simmers, Tim; Tsiodras, Sotirios; Parissis, John
2017-05-01
The interaction of influenza infection with the pathogenesis of acute heart failure (AHF) and the worsening of chronic heart failure (CHF) is rather complex. The deleterious effects of influenza infection on AHF/CHF can be attenuated by specific immunization. Our review aimed to summarize the efficacy, effectiveness, safety, and dosage of anti-influenza vaccination in HF. In this literature review, we searched MEDLINE and EMBASE from January 1st 1966 to December 31st, 2016, for studies examining the association between AHF/CHF, influenza infections, and anti-influenza immunizations. We used broad criteria to increase the sensitivity of the search. HF was a prerequisite for our search. The search fields used included "heart failure," "vaccination," "influenza," "immunization" along with variants of these terms. No restrictions on the type of study design were applied. The most common clinical scenario is exacerbation of pre-existing CHF by influenza infection. Scarce evidence supports a potential positive association of influenza infection with AHF. Vaccinated patients with pre-existing CHF have reduced all-cause morbidity and mortality, but effects are not consistently documented. Immunization with higher antigen quantity may confer additional protection, but such aggressive approach has not been generally advocated. Further studies are needed to delineate the role of influenza infection on AHF/CHF pathogenesis and maintenance. Annual anti-influenza vaccination appears to be an effective measure for secondary prevention in HF. Better immunization strategies and more efficacious vaccines are urgently necessary.
2011-01-01
Background Chronic heart failure (CHF) is a chronic debilitating condition with economic consequences, mostly because of frequent hospitalisations. Physical activity and adequate self-management capacity are important risk reduction strategies in the management of CHF. The Home-Heart-Walk is a self-monitoring intervention. This model of intervention has adapted the 6-minute walk test as a home-based activity that is self-administered and can be used for monitoring physical functional capacity in people with CHF. The aim of the Home-Heart-Walk program is to promote adherence to physical activity recommendations and improving self-management in people with CHF. Methods/Design A randomised controlled trial is being conducted in English speaking people with CHF in four hospitals in Sydney, Australia. Individuals diagnosed with CHF, in New York Heart Association Functional Class II or III, with a previous admission to hospital for CHF are eligible to participate. Based on a previous CHF study and a loss to follow-up of 10%, 166 participants are required to be able to detect a 12-point difference in the study primary endpoint (SF-36 physical function domain). All enrolled participant receive an information session with a cardiovascular nurse. This information session covers key self-management components of CHF: daily weight; diet (salt reduction); medication adherence; and physical activity. Participants are randomised to either intervention or control group through the study randomisation centre after baseline questionnaires and assessment are completed. For people in the intervention group, the research nurse also explains the weekly Home-Heart-Walk protocol. All participants receive monthly phone calls from a research coordinator for six months, and outcome measures are conducted at one, three and six months. The primary outcome of the trial is the physical functioning domain of quality of life, measured by the physical functioning subscale of the Medical Outcome Study Short Form -36. Secondary outcomes include physical functional capacity measured by the standard six minute walk test, self-management capacity, health related quality of life measured by Medical Outcome Study Short Form -36 and Minnesota Living With Heart Failure Questionnaire, self-efficacy and self-care behaviour. Discussion A self-monitoring intervention that can improve individual's exercise self-efficacy, self-management capacity could have potential significance in improving the management of people with chronic heart failure in community settings. Trial Registration Australian New Zealand Clinical Trial Registry 12609000437268 PMID:21366927
Du, Hui Y; Newton, Phillip J; Zecchin, Robert; Denniss, Robert; Salamonson, Yenna; Everett, Bronwyn; Currow, David C; Macdonald, Peter S; Davidson, Patricia M
2011-03-02
Chronic heart failure (CHF) is a chronic debilitating condition with economic consequences, mostly because of frequent hospitalisations. Physical activity and adequate self-management capacity are important risk reduction strategies in the management of CHF. The Home-Heart-Walk is a self-monitoring intervention. This model of intervention has adapted the 6-minute walk test as a home-based activity that is self-administered and can be used for monitoring physical functional capacity in people with CHF. The aim of the Home-Heart-Walk program is to promote adherence to physical activity recommendations and improving self-management in people with CHF. A randomised controlled trial is being conducted in English speaking people with CHF in four hospitals in Sydney, Australia. Individuals diagnosed with CHF, in New York Heart Association Functional Class II or III, with a previous admission to hospital for CHF are eligible to participate. Based on a previous CHF study and a loss to follow-up of 10%, 166 participants are required to be able to detect a 12-point difference in the study primary endpoint (SF-36 physical function domain).All enrolled participant receive an information session with a cardiovascular nurse. This information session covers key self-management components of CHF: daily weight; diet (salt reduction); medication adherence; and physical activity. Participants are randomised to either intervention or control group through the study randomisation centre after baseline questionnaires and assessment are completed. For people in the intervention group, the research nurse also explains the weekly Home-Heart-Walk protocol. All participants receive monthly phone calls from a research coordinator for six months, and outcome measures are conducted at one, three and six months. The primary outcome of the trial is the physical functioning domain of quality of life, measured by the physical functioning subscale of the Medical Outcome Study Short Form -36. Secondary outcomes include physical functional capacity measured by the standard six minute walk test, self-management capacity, health related quality of life measured by Medical Outcome Study Short Form -36 and Minnesota Living With Heart Failure Questionnaire, self-efficacy and self-care behaviour. A self-monitoring intervention that can improve individual's exercise self-efficacy, self-management capacity could have potential significance in improving the management of people with chronic heart failure in community settings. Australian New Zealand Clinical Trial Registry 12609000437268.
Borghi, Josephine; Makawia, Suzan; Kuwawenaruwa, August
2015-01-01
Community-based health insurance expansion has been proposed as a financing solution for the sizable informal sector in low-income settings. However, there is limited evidence of the administrative costs of such schemes. We assessed annual facility and district-level costs of running the Community Health Fund (CHF), a voluntary health insurance scheme for the informal sector in a rural and an urban district from the same region in Tanzania. Information on resource use, CHF membership and revenue was obtained from district managers and health workers from two facilities in each district. The administrative cost per CHF member household and the cost to revenue ratio were estimated. Revenue collection was the most costly activity at facility level (78% of total costs), followed by stewardship and management (13%) and pooling of funds (10%). Stewardship and management was the main activity at district level. The administration cost per CHF member household ranged from USD 3.33 to USD 12.12 per year. The cost to revenue ratio ranged from 50% to 364%. The cost of administering the CHF was high relative to revenue generated. Similar studies from other settings should be encouraged. PMID:24334331
Hospitalization for congestive heart failure: is it still a cardiology business?
Grigioni, Francesco; Carinci, Valeria; Favero, Luca; Bacchi Reggiani, Letizia; Magnani, Gaia; Potena, Luciano; Barbieri, Alessandra; Magelli, Carlo; Branzi, Angelo; Magnani, Bruno
2002-01-01
Hospital management of CHF and predictors of hospital mortality remain unclear. To address these issues, we analyzed the hospital admissions for CHF during 1996 in a large university hospital. Patients discharged with the principal diagnosis of CHF were considered eligible for the study. Among the 1511 patients (3% of all discharges) who satisfied the inclusion criteria, 75% were treated in general medicine departments (GMD) and 22% in cardiology units (CU). Patients admitted to GMD were older than those treated in CU (79+/-10 vs. 68+/-15 years, P<0.001), included a higher proportion of females (56% vs. 37%, P<0.001), and presented a higher rate of hospital mortality (13% vs. 4%, P<0.001). The overall mean length of stay was 11+/-9 days. At multivariate analysis, length of stay was not associated with the department (i.e. GMD/CU) (P=0.273). CHF is a common lethal condition often requiring treatment in GMD. Length of stay appears to depend more on patients' characteristics than on differences in practice between GMD and CU. Patients admitted to GMD present higher rates of comorbidity and hospital mortality. Strategies are urgently needed to improve hospital management of CHF.
[Pathogenetic and Prognostic Role of Growth Factors in the Development of Chronic Heart Failure].
Teplyakov, A T; Berezikova, E N; Shilov, S N; Efremova, A V; Pustovetova, M G; Popova, A A; Grakova, E V; Torim, Y Y; Safronov, I D; Andriyanova, A V
2017-10-01
To study the role of growth factors ((vascular endothelial growth factor (VEGF), platelet derived growth factor AB (PDGF-AB) and basic fibroblast growth factor (FGF-basic)) in the development and progression of chronic heart failure (CHF) in patients with ishcemic heart disease (IHD). We included in this study 94 patients with CHF. The control group comprised 32 persons. Blood serum levels of growth factors were determined at baseline and after 12 months of observation by enzyme-linked immunosorbent assay. VEGF, PDGF-AB and FGF-basic play an important role in the pathogenesis and progression of heart failure in patients with IHD, determining the increased risk of adverse cardiovascular events in this pathology. Serum activity of growth factors characterizes the severity and course of CHF: with disease progression levels of VEGF and FGF-basic decrease and PDGF-AB concentration increases. Initial low level of VEGF expression regardless of the sex of the patient's sex, significantly low level of FGF-basic and significantly high PDGF-AB in men characterizes unfavorable course of CHF. A correlation has been established between blood serum levels of VEGF, PDGF-AB and FGF-basic and severity and course of CHF.
DOE Office of Scientific and Technical Information (OSTI.GOV)
LeJemtel, T.H.; Scortichini, D.; Katz, S.
In patients with chronic congestive heart failure (CHF), skeletal muscle blood flow can be measured directly by the continuous thermodilution technique and by the xenon-133 clearance method. The continuous thermodilution technique requires retrograde catheterization of the femoral vein and, thus, cannot be repeated conveniently in patients during evaluation of pharmacologic interventions. The xenon-133 clearance, which requires only an intramuscular injection, allows repeated determination of skeletal muscle blood flow. In patients with severe CHF, a fixed capacity of the skeletal muscle vasculature to dilate appears to limit maximal exercise performance. Moreover, the changes in peak skeletal muscle blood flow noted duringmore » long-term administration of captopril, an angiotensin-converting enzyme inhibitor, appears to correlate with the changes in aerobic capacity. In patients with CHF, resting supine deep femoral vein oxygen content can be used as an indirect measurement of resting skeletal muscle blood flow. The absence of a steady state complicates the determination of peak skeletal muscle blood flow reached during graded bicycle or treadmill exercise in patients with chronic CHF. Indirect assessments of skeletal muscle blood flow and metabolism during exercise performed at submaximal work loads are currently developed in patients with chronic CHF.« less
Antiñolo, María; Bravo, Iván; Jiménez, Elena; Ballesteros, Bernabé; Albaladejo, José
2017-11-02
We report here the rate coefficients for the OH reactions (k OH ) with E-CF 3 CH═CHF and Z-CF 3 CH═CHF, potential substitutes of HFC-134a, as a function of temperature (263-358 K) and pressure (45-300 Torr) by pulsed laser photolysis coupled to laser-induced fluorescence techniques. For the E-isomer, the existing discrepancy among previous results on the T dependence of k OH needs to be elucidated. For the Z-isomer, this work constitutes the first absolute determination of k OH . No pressure dependence of k OH was observed, while k OH exhibits a non-Arrhenius behavior: k OH (E) = [Formula: see text] and k OH (Z) = [Formula: see text] cm 3 molecule -1 s -1 , where uncertainties are 2σ. UV absorption cross sections, σ λ , are reported for the first time. From σ λ and considering a photolysis quantum yield of 1, an upper limit for the photolysis rate coefficients and lifetimes due to this process in the troposphere are estimated: 3 × 10 -8 s -1 and >1 year for the E-isomer and 2 × 10 -7 s -1 and >2 months for Z-CF 3 CH═CHF, respectively. Under these conditions, the overall estimated tropospheric lifetimes are 15 days (for the E-isomer) and 8 days (for the Z-isomer), the major degradation pathway being the OH reaction, with a contribution of the photolytic pathway of less than 3% (for E) and 13% (for Z). IR absorption cross sections were determined both experimentally (500-4000 cm -1 ) and theoretically (0-2000 cm -1 ). From the theoretical IR measurements, it is concluded that the contribution of the 0-500 cm -1 region to the total integrated cross sections is appreciable for the E-isomer (9%) but almost negligible for the Z-isomer (0.5%). Nevertheless, the impact on their radiative efficiency and global warming potential is negligible.
Gunay-Aygun, Meral; Avner, Ellis D.; Bacallo, Robert L.; Choyke, Peter L.; Flynn, Joseph T.; Germino, Gregory G.; Guay-Woodford, Lisa; Harris, Peter; Heller, Theo; Ingelfinger, Julie; Kaskel, Frederick; Kleta, Robert; LaRusso, Nicholas F.; Mohan, Parvathi; Pazour, Gregory J.; Shneider, Benjamin L.; Torres, Vicente E.; Wilson, Patricia; Zak, Colleen; Zhou, Jing; Gahl, William A.
2010-01-01
Researchers and clinicians with expertise in autosomal recessive polycystic kidney disease and congenital hepatic fibrosis (ARPKD/CHF) and related fields met on May 5-6, 2005, on the National Institutes of Health (NIH) campus for a 1.5-day symposium sponsored by the NIH Office of Rare Diseases, the National Human Genome Research Institute (NHGRI), and in part by the ARPKD/CHF Alliance. The meeting addressed the present status and the future of ARPKD/CHF research. PMID:16887426
Watanabe, Kenichi; Arumugam, Somasundaram; Sreedhar, Remya; Thandavarayan, Rajarajan A; Nakamura, Takashi; Nakamura, Masahiko; Harima, Meilei; Yoneyama, Hiroyuki; Suzuki, Kenji
2015-07-01
Carbohydrate sulfotransferase 15 (CHST15) is a sulfotransferase responsible for biosynthesis of chondroitin sulfate E (CS-E), which plays important roles in numerous biological events such as biosynthesis of proinflammatory cytokines. However, the effects of CHST15 siRNA in rats with chronic heart failure (CHF) after experimental autoimmune myocarditis (EAM) have not yet been investigated. CHF was elicited in Lewis rats by immunization with cardiac myosin, and after immunization, the rats were divided into two groups and treated with either CHST15 siRNA (2μg/week) or vehicle. Age matched normal rats without immunizations were also included in this study. After 7weeks of treatment, we investigated the effects of CHST15 siRNA on cardiac function, proinflammatory cytokines, and cardiac remodeling in EAM rats. Myocardial functional parameters measured by hemodynamic and echocardiographic studies were significantly improved by CHST15 siRNA treatment in rats with CHF compared with that of vehicle-treated CHF rats. CHST15 siRNA significantly reduced cardiac fibrosis, and hypertrophy and its marker molecules (left ventricular (LV) mRNA expressions of transforming growth factor beta1, collagens I and III, and atrial natriuretic peptide) compared with vehicle-treated CHF rats. CHF-induced increased myocardial mRNA expressions of proinflammatory cytokines [interleukin (IL)-6, IL-1β], monocyte chemoattractant protein-1, and matrix metalloproteinases (MMP-2 and -9), and CHST15 were also suppressed by the treatment with CHST15 siRNA. Western blotting study has confirmed the results obtained from mRNA analysis as CHST15 siRNA treated rats expressed reduced levels of inflammatory and cardiac remodeling marker proteins. Our results demonstrate for the first time, that CHST15 siRNA treatment significantly improved LV function and ameliorated the progression of cardiac remodeling in rats with CHF after EAM. Copyright © 2015 Elsevier Inc. All rights reserved.
Muscle oxygen transport and utilization in heart failure: implications for exercise (in)tolerance.
Poole, David C; Hirai, Daniel M; Copp, Steven W; Musch, Timothy I
2012-03-01
The defining characteristic of chronic heart failure (CHF) is an exercise intolerance that is inextricably linked to structural and functional aberrations in the O(2) transport pathway. CHF reduces muscle O(2) supply while simultaneously increasing O(2) demands. CHF severity varies from moderate to severe and is assessed commonly in terms of the maximum O(2) uptake, which relates closely to patient morbidity and mortality in CHF and forms the basis for Weber and colleagues' (167) classifications of heart failure, speed of the O(2) uptake kinetics following exercise onset and during recovery, and the capacity to perform submaximal exercise. As the heart fails, cardiovascular regulation shifts from controlling cardiac output as a means for supplying the oxidative energetic needs of exercising skeletal muscle and other organs to preventing catastrophic swings in blood pressure. This shift is mediated by a complex array of events that include altered reflex and humoral control of the circulation, required to prevent the skeletal muscle "sleeping giant" from outstripping the pathologically limited cardiac output and secondarily impacts lung (and respiratory muscle), vascular, and locomotory muscle function. Recently, interest has also focused on the dysregulation of inflammatory mediators including tumor necrosis factor-α and interleukin-1β as well as reactive oxygen species as mediators of systemic and muscle dysfunction. This brief review focuses on skeletal muscle to address the mechanistic bases for the reduced maximum O(2) uptake, slowed O(2) uptake kinetics, and exercise intolerance in CHF. Experimental evidence in humans and animal models of CHF unveils the microvascular cause(s) and consequences of the O(2) supply (decreased)/O(2) demand (increased) imbalance emblematic of CHF. Therapeutic strategies to improve muscle microvascular and oxidative function (e.g., exercise training and anti-inflammatory, antioxidant strategies, in particular) and hence patient exercise tolerance and quality of life are presented within their appropriate context of the O(2) transport pathway.
Kadoglou, Nikolaos Pe; Mandila, Christina; Karavidas, Apostolos; Farmakis, Dimitrios; Matzaraki, Vasiliki; Varounis, Christos; Arapi, Sofia; Perpinia, Anastasia; Parissis, John
2017-05-01
Background/design Functional electrical stimulation of lower limb muscles is an alternative method of training in patients with chronic heart failure (CHF). Although it improves exercise capacity in CHF, we performed a randomised, placebo-controlled study to investigate its effects on long-term clinical outcomes. Methods We randomly assigned 120 patients, aged 71 ± 8 years, with stable CHF (New York Heart Association (NYHA) class II/III (63%/37%), mean left ventricular ejection fraction 28 ± 5%), to either a 6-week functional electrical stimulation training programme or placebo. Patients were followed for up to 19 months for death and/or hospitalisation due to CHF decompensation. Results At baseline, there were no significant differences in demographic parameters, CHF severity and medications between groups. During a median follow-up of 383 days, 14 patients died (11 cardiac, three non-cardiac deaths), while 40 patients were hospitalised for CHF decompensation. Mortality did not differ between groups (log rank test P = 0.680), while the heart failure-related hospitalisation rate was significantly lower in the functional electrical stimulation group (hazard ratio (HR) 0.40, 95% confidence interval (CI) 0.21-0.78, P = 0.007). The latter difference remained significant after adjustment for prognostic factors: age, gender, baseline NYHA class and left ventricular ejection fraction (HR 0.22, 95% CI 0.10-0.46, P < 0.001). Compared to placebo, functional electrical stimulation training was associated with a lower occurrence of the composite endpoint (death or heart failure-related hospitalisation) after adjustment for the above-mentioned prognostic factors (HR 0.21, 95% CI 0.103-0.435, P < 0.001). However, that effect was mostly driven by the favourable change in hospitalisation rates. Conclusions In CHF patients, 6 weeks functional electrical stimulation training reduced the risk of heart failure-related hospitalisations, without affecting the mortality rate. The beneficial long-term effects of this alternative method of training require further investigation.
Effectiveness of an educational self-management program for outpatients with chronic heart failure.
Otsu, Haruka; Moriyama, Michiko
2011-12-01
The occurrence rate of chronic heart failure (CHF) in Japan is estimated to be 50,000 per one million persons. It is important for the Japanese medical financial system to institute a program of disease management in order to prevent the deterioration of persons with CHF. However, there are still few studies on the disease management of CHF in Japan. Therefore, the purpose of this study was to provide an educational self-management program to Japanese outpatients with CHF in order to improve their clinical outcomes. A randomized, controlled trial with 102 outpatients with CHF was conducted. There were 50 participants in the intervention group and 52 participants in the control group. The control group received medical treatment and standard care. In addition to this, the intervention group also received an educational program for 6 months. The program consisted of six nurse-directed sessions that were provided to each outpatient once per month in a clinical setting for a total of 6 months. A follow-up session was conducted each month for 6 months. The data collection was carried out at the start of the program and at 3, 6, 9, and 12 months. Significant differences could be observed in the primary and secondary outcomes and in the process indicators between the two groups after the program began. In other words, all the indicators improved for the intervention group, compared to the control group. Therefore, this program was considered to be effective. Further long-term care is necessary for outpatients with CHF in order to prevent their deterioration and to maintain their health status, even though this 6 month program did provide them with proper knowledge regarding self-care for CHF and affected their therapy results. © 2010 The Authors. Japan Journal of Nursing Science © 2010 Japan Academy of Nursing Science.
Koller, Lorenz; Stojkovic, Stefan; Richter, Bernhard; Sulzgruber, Patrick; Potolidis, Christos; Liebhart, Florian; Mörtl, Deddo; Berger, Rudolf; Goliasch, Georg; Wojta, Johann; Hülsmann, Martin; Niessner, Alexander
2017-04-01
This study investigated the predictive value of soluble urokinase-type plasminogen activator receptor (suPAR) in patients with chronic heart failure (CHF). SuPAR originates from proteolytic cleavage of the membrane-bound receptor from activated immune and endothelial cells and reflects the level of immune activation. As inflammation plays a crucial role in the complex pathophysiology of CHF, we hypothesized that suPAR might be a suitable prognostic biomarker in patients with CHF. SuPAR levels were determined in 319 patients with CHF admitted to our outpatient department for heart failure and in a second cohort consisting of 346 patients with CHF, for validation. During a median follow-up time of 3.2 years, 119 patients (37.3%) died. SuPAR was a strong predictor of mortality with a crude hazard ratio (HR) per increase of 1 SD (HR per 1 SD) of 1.96 (95% confidence interval [CI]: 1.63 to 2.35; p < 0.001) in univariate analysis and remained significant after comprehensive multivariate adjustment with an adjusted HR per 1 SD of 1.38 (95% CI: 1.04 to 1.83; p = 0.026). SuPAR added prognostic value beyond the multivariate model indicated by improvements in C-statistics (area under the curve: 0.72 vs 0.74, respectively; p = 0.02), the category-free net reclassification index (24.9%; p = 0.032), and the integrated discrimination improvement (0.011; p = 0.05). Validation in the second cohort yielded consistent results. SuPAR is a strong and independent predictor of mortality in patients with CHF, potentially suitable to refine risk assessment in this vulnerable group of patients. Our results emphasize the impact of immune activation on survival in patients with CHF. Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.
Gladowski, Patricia; Fetterolf, Donald; Beals, Susan; Holleran, Mary Kay; Reich, Sanford
2003-01-01
The aim of this article was to measure guideline compliance in the care of health plan members diagnosed with congestive heart failure (CHF). Chart review was conducted on members with a discharge diagnosis of CHF (n = 2,697). Information was entered onto a scannable form designed by the health plan, which was coupled to an optical character recognition reader and entered into a database. Eighty-four percent of the patients had an ejection fraction (EF) measured. An angiotensin-converting enzyme inhibitor was prescribed to 72% of patients with an EF less than 40%. Comorbidities and other measures were evaluated and based on guideline recommendations. Most of the CHF patients in this health plan are being treated appropriately during posthospitalization for CHF. The use of a novel, cost-effective method for data collection resulted in the rapid acquisition of clinical data for analysis.
Severe congestive heart failure patient on amiodarone presenting with myxedemic coma: a case report.
Shaheen, Mazen
2009-01-01
This is a case report of myxedema coma secondary to amiodarone-induced hypothyroidism in a patient with severe congestive heart failure (CHF). To our knowledge and after reviewing the literature there is one case report of myxedema coma during long term amiodarone therapy. Myxedema coma is a life threatening condition that carries a mortality reaching as high as 20% with treatment. The condition is treated with intravenous thyroxine (T4) or intravenous tri-iodo-thyronine (T3). Patients with CHF on amiodarone may suffer serious morbidity and mortality from hypothyroidism, and thus may deserve closer follow up for thyroid stimulating hormone (TSH) levels. This case report carries an important clinical application given the frequent usage of amiodarone among CHF patients. The myriad clinical presentation of myxedema coma and its serious morbidity and mortality stresses the need to suspect this clinical syndrome among CHF patients presenting with hypotension, weakness or other unexplained symptoms.
Kapanadze, L G; Petrukhina, A A; Nasonova, S N; Skvortsov, A A; Mareev, V Iu
2011-01-01
Despite obvious achievements during last decades in studies of pathogenesis and search for effective ways of treatment of chronic heart failure (CHF) it remains one of most severe and prognostically unfavorable diseases of the cardiovascular system. Thereby determination of predictors of death and detection of high risk patients for more active drug interventions on CHF progression appears to be actual. It has been shown in a number of epidemiological and cohort studies that low arterial pressure (AP) serves as an independent risk factor of prognosis in patients with CHF. In this paper we present short literature review on this theme, consideration of possible mechanisms of negative effect of arterial hypotension on function of vitally important organs in patients with CHF, and summation of data of studies which have demonstrated relationship between low level of AP and worsening of prognosis.
Siabani, Soraya; Leeder, Stephen R; Davidson, Patricia M
2013-01-01
Chronic heart failure (CHF) is a costly condition that places large demands on self-care. Failure to adhere with self-care recommendations is common and associated with frequent hospitalization. Understanding the factors that enable or inhibit self-care is essential in developing effective health care interventions. This qualitative review was conducted to address the research question, "What are the barriers and facilitators to self-care among patients with CHF?" Electronic databases including Medline, EMBASE, CINAHL, Web of Science, Scopus and Google scholar were searched. Articles were included if they were peer reviewed (1995 to 2012), in English language and investigated at least one contextual or individual factor impacting on self-care in CHF patients > 18years. The criteria defined by Kuper et al. including clarity and appropriateness of sampling, data collection and data analysis were used to appraise the quality of articles. Twenty-three articles met the inclusion criteria. Factors impacting on self-care were included factors related to symptoms of CHF and the self-care process; factors related to personal characteristics; and factors related to environment and self-care system. Important factors such as socioeconomic situation and education level have not been explored extensively and there were minimal data on the influence of age, gender, self-confidence and duration of disease. Although there is an emerging literature, further research is required to address the barriers and facilitators to self-care in patients with CHF in order to provide an appropriate guide for intervention strategies to improve self-care in CHF.
Anfinogenova, Yana; Grakova, Elena V; Shvedova, Maria; Kopieva, Kristina V; Teplyakov, Alexander T; Popov, Sergey V
2018-05-01
Diabetes mellitus is a chronic disease requiring lifelong control with hypoglycemic agents that must demonstrate excellent efficacy and safety profiles. In patients taking glucose-lowering drugs, hypoglycemia is a common cause of death associated with arrhythmias, increased thrombus formation, and specific effects of catecholamines due to sympathoadrenal activation. Focus is now shifting from merely glycemic control to multifactorial approach. In the context of individual drugs and classes, this article reviews interdisciplinary strategies evaluating metabolic effects of drugs for treatment of chronic heart failure (CHF) which can mask characteristic hypoglycemia symptoms. Hypoglycemia unawareness and cardiac autonomic neuropathy are discussed. Data suggesting that hypoglycemia modulates immune response are reviewed. The potential role of gut microbiota in improving health of patients with diabetes and CHF is emphasized. Reports stating that nondiabetic CHF patients can have life-threatening hypoglycemia associated with imbalance of thyroid hormones are discussed. Regular glycemic control based on HbA1c measurements and adequate pharmacotherapy remain the priorities in diabetes management. New antihyperglycemic drugs with safer profiles should be preferred in vulnerable CHF patients. Multidrug interactions must be considered. Emerging therapies with reduced hypoglycemia risk, telemedicine, sensor technologies, and genetic testing predicting hypoglycemia risk may help solving the challenges of hypoglycemia in CHF patients with diabetes. Interdisciplinary work may involve cardiologists, diabetologists/endocrinologists, immunologists, gastroenterologists, microbiologists, nutritionists, imaging specialists, geneticists, telemedicine experts, and other relevant specialists. This review emphasizes that systematic knowledge on pathophysiology of hypoglycemia in diabetic patients with CHF is largely lacking and the gaps in our understanding require further discoveries.
Betihavas, Vasiliki; Newton, Phillip J; Du, Hui Yun; Macdonald, Peter S; Frost, Steven A; Stewart, Simon; Davidson, Patricia M
2011-08-01
The importance of the nursing role in chronic heart failure (CHF) management is increasingly recognised. With the recent release of the National Health and Hospitals Reform Commission (NHHRC) report in Australia, a review of nursing roles in CHF management is timely and appropriate. This paper aims to discuss the implications of the NHHRC report and nursing roles in the context of CHF management in Australia. The electronic databases, Thomson Rheuters Web of Knowledge, Scopus and the Cumulative Index to Nursing and Allied Health Literature (CINAHL), were searched using keywords including; "heart failure", "management", "Australia" and "nursing". In addition policy documents were reviewed including statements and reports from key professional organisations and Government Departments to identify issues impacting on nursing roles in CHF management. There is a growing need for the prevention and control of chronic conditions, such as CHF. This involves an increasing emphasis on specialist cardiovascular nurses in community based settings, both in outreach and inreach health service models. This review has highlighted the need to base nursing roles on evidence based principles and identify the importance of the nursing role in coordinating and managing CHF care in both independent and collaborative practice settings. The importance of the nursing role in early chronic disease symptom recognition and implementing strategies to prevent further deterioration of individuals is crucial to improving health outcomes. Consideration should be given to ensure that evidence based principles are adopted in models of nursing care. Copyright © 2010 Australian College of Critical Care Nurses Ltd. Published by Elsevier Ltd. All rights reserved.
Sanchez, Pablo; Lancaster, Jordan J; Weigand, Kyle; Mohran, Saffie-Alrahman Ezz-Eldin; Goldman, Steven; Juneman, Elizabeth
2017-10-01
For chronic heart failure (CHF), more emphasis has been placed on evaluation of systolic as opposed to diastolic function. Within the study of diastology, measurements of left ventricular (LV) longitudinal myocardial relaxation have the most validation. Anterior wall radial myocardial tissue relaxation velocities along with mitral valve inflow (MVI) patterns are applicable diastolic parameters in the differentiation between moderate and severe disease in the ischemic rat model of CHF. Myocardial tissue relaxation velocities correlate with traditional measurements of diastolic function (ie, hemodynamics, Tau, and diastolic pressure-volume relationships). Male Sprague-Dawley rats underwent left coronary artery ligation or sham operation. Echocardiography was performed at 3 and 6 weeks after coronary ligation to evaluate LV ejection fraction (EF) and LV diastolic function through MVI patterns (E, A, and E/A) and Doppler imaging of the anterior wall (e' and a'). The rats were categorized into moderate or severe CHF according to their LV EF at 3 weeks postligation. Invasive hemodynamic measurements with solid-state pressure catheters were obtained at the 6-week endpoint. Moderate (N = 20) and severe CHF (N = 22) rats had significantly (P < .05) different EFs, hemodynamics, and diastolic pressure-volume relationships. Early diastolic anterior wall radial relaxation velocities as well as E/e' ratios separated moderate from severe CHF and both diastolic parameters had strong correlations with invasive hemodynamic measurements of diastolic function. Radial anterior wall e' and E/e' can be used for serial assessment of diastolic function in rats with moderate and severe CHF. Copyright © 2017 Elsevier Inc. All rights reserved.
Size and shape of right heart chambers in mitral valve regurgitation in small-breed dogs.
Carlsson, C; Häggström, J; Eriksson, A; Järvinen, A -K; Kvart, C; Lord, P
2009-01-01
The contribution of right heart (RH) chamber enlargement to general heart enlargement seen on thoracic radiographs in mitral regurgitation (MR) is not known. To determine the size and shape of the RH chambers in normal dogs and dogs with varying degrees of MR. Fifty-four privately owned dogs: 13 normal, 41 with varying degrees of MR including 25 with congestive heart failure (CHF). Archived first pass radionuclide angiocardiograms were used to produce static images of the RH and left heart (LH) chambers. Indexes of size and shape of the RH and LH chambers were related to severity of MR determined by heart rate-normalized pulmonary transit time (nPTT), vertebral heart scale (VHS), and clinical status. RH shape was measured by a circularity index of RH short axis/long axis. A 2nd degree polynomial fit best described the ratios; RH/LH dimension to nPTT (R(2)= 0.62) and to VHS (R(2)= 0.43), RH/LH area to nPTT (R(2)= 0.64) and to VHS (R(2)= 0.58), all P < .001. RH circularity was decreased in CHF, P < .001. In CHF, the RH chambers of 16 dogs were both flattened and enlarged, whereas 9 had convex septal borders. RH chambers are not significantly dilated in dogs with mild to moderate MR without CHF. In CHF, RH chambers enlarge and also may be compressed by the LH chambers. Pulmonary hypertension probably is present in some dogs with CHF. Increased sternal contact is not a useful sign of right-sided heart dilatation in MR.
Intelligent data analysis: the best approach for chronic heart failure (CHF) follow up management.
Mohammadzadeh, Niloofar; Safdari, Reza; Baraani, Alireza; Mohammadzadeh, Farshid
2014-08-01
Intelligent data analysis has ability to prepare and present complex relations between symptoms and diseases, medical and treatment consequences and definitely has significant role in improving follow-up management of chronic heart failure (CHF) patients, increasing speed and accuracy in diagnosis and treatments; reducing costs, designing and implementation of clinical guidelines. The aim of this article is to describe intelligent data analysis methods in order to improve patient monitoring in follow and treatment of chronic heart failure patients as the best approach for CHF follow up management. Minimum data set (MDS) requirements for monitoring and follow up of CHF patient designed in checklist with six main parts. All CHF patients that discharged in 2013 from Tehran heart center have been selected. The MDS for monitoring CHF patient status were collected during 5 months in three different times of follow up. Gathered data was imported in RAPIDMINER 5 software. Modeling was based on decision trees methods such as C4.5, CHAID, ID3 and k-Nearest Neighbors algorithm (K-NN) with k=1. Final analysis was based on voting method. Decision trees and K-NN evaluate according to Cross-Validation. Creating and using standard terminologies and databases consistent with these terminologies help to meet the challenges related to data collection from various places and data application in intelligent data analysis. It should be noted that intelligent analysis of health data and intelligent system can never replace cardiologists. It can only act as a helpful tool for the cardiologist's decisions making.
Association of Hospital Spending Intensity With Mortality and Readmission Rates in Ontario Hospitals
Stukel, Therese A.; Fisher, Elliott S.; Alter, David A.; Guttmann, Astrid; Ko, Dennis T.; Fung, Kinwah; Wodchis, Walter P.; Baxter, Nancy N.; Earle, Craig C.; Lee, Douglas S.
2012-01-01
Context The extent to which better spending produces higher-quality care and better patient outcomes in a universal health care system with selective access to medical technology is unknown. Objective To assess whether acute care patients admitted to higher-spending hospitals have lower mortality and readmissions. Design, Setting, and Patients The study population comprised adults (> 18 years) in Ontario, Canada, with a first admission for acute myocardial infarction (AMI) (n=179 139), congestive heart failure (CHF) (n=92 377), hip fracture (n=90 046), or colon cancer (n=26 195) during 1998–2008, with follow-up to 1 year. The exposure measure was the index hospital’s end-of-life expenditure index for hospital, physician, and emergency department services. Main Outcome Measures The primary outcomes were 30-day and 1-year mortality and readmissions and major cardiac events (readmissions for AMI, angina, CHF, or death) for AMI and CHF. Results Patients’ baseline health status was similar across hospital expenditure groups. Patients admitted to hospitals in the highest- vs lowest-spending intensity terciles had lower rates of all adverse outcomes. In the highest- vs lowest-spending hospitals, respectively, the age- and sex-adjusted 30-day mortality rate was 12.7% vs 12.8% for AMI, 10.2% vs 12.4% for CHF, 7.7% vs 9.7% for hip fracture, and 3.3% vs 3.9% for CHF; fully adjusted relative 30-day mortality rates were 0.93 (95% CI, 0.89–0.98) for AMI, 0.81 (95% CI, 0.76–0.86) for CHF, 0.74 (95% CI, 0.68–0.80) for hip fracture, and 0.78 (95% CI, 0.66–0.91) for colon cancer. Results for 1-year mortality, readmissions, and major cardiac events were similar. Higher-spending hospitals had higher nursing staff ratios, and their patients received more inpatient medical specialist visits, interventional (AMI cohort) and medical (AMI and CHF cohorts) cardiac therapies, preoperative specialty care (colon cancer cohort), and postdischarge collaborative care with a cardiologist and primary care physician (AMI and CHF cohorts). Conclusion Among Ontario hospitals, higher spending intensity was associated with lower mortality, readmissions, and cardiac event rates. PMID:22416099
Gopi, R; Ramanathan, N; Sundararajan, K
2014-07-24
The 1:1 hydrogen-bonded complex of fluoroform and hydrogen chloride was studied using matrix-isolation infrared spectroscopy and ab initio computations. Using B3LYP and MP2 levels of theory with 6-311++G(d,p) and aug-cc-pVDZ basis sets, the structures of the complexes and their energies were computed. For the 1:1 CHF3-HCl complexes, ab initio computations showed two minima, one cyclic and the other acyclic. The cyclic complex was found to have C-H · · · Cl and C-F · · · H interactions, where CHF3 and HCl sub-molecules act as proton donor and proton acceptor, respectively. The second minimum corresponded to an acyclic complex stabilized only by the C-F · · · H interaction, in which CHF3 is the proton acceptor. Experimentally, we could trap the 1:1 CHF3-HCl cyclic complex in an argon matrix, where a blue-shift in the C-H stretching mode of the CHF3 sub-molecule was observed. To understand the nature of the interactions, Atoms in Molecules and Natural Bond Orbital analyses were carried out to unravel the reasons for blue-shifting of the C-H stretching frequency in these complexes.
Kasai, Takatoshi; Narui, Koji; Dohi, Tomotaka; Takaya, Hisashi; Yanagisawa, Naotake; Dungan, George; Ishiwata, Sugao; Ohno, Minoru; Ymaguchi, Tetsu; Momomura, Shin-ichi
2006-09-01
Cheyne-Stokes respiration with central sleep apnea (CSR-CSA) in congestive heart failure (CHF) is generally considered a poor prognostic indicator, but treatment of CSR-CSA using an adaptive servo-ventilation (ASV) device has been developed. This is the first evaluation of its use in the management of CSR-CSA in Japanese CHF patients. Four CHF patients with CSR-CSA that was unresponsive to conventional positive airway pressure (CPAP) underwent 3 nights of polysomnography: baseline, CPAP or bi-level PAP, and on the ASV. The apnea - hypopnea index (AHI) and central-AHI (CAHI) were markedly improved on ASV (AHI 62.7+/-10.1 to 5.9+/-2.2 /h, p=0.0006, CAHI 54.5+/-6.7 to 5.6+/-2.3 /h, p=0.007). In addition, the sleep quality improved significantly on ASV, including arousal index (62.0+/-10.5 to 18.7 +/-6.2 /h, p=0.012), percentage of slow-wave sleep (2.6+/-2.6 to 19.4+/-4.8 %, p=0.042). ASV markedly improved CSR-CSA in patients with CHF. It is a promising treatment for Japanese patients with CHF.
Energy transfer of highly vibrationally excited naphthalene: collisions with CHF3, CF4, and Kr.
Chen Hsu, Hsu; Tsai, Ming-Tsang; Dyakov, Yuri A; Ni, Chi-Kung
2011-08-07
Energy transfer of highly vibrationally excited naphthalene in the triplet state in collisions with CHF(3), CF(4), and Kr was studied using a crossed-beam apparatus along with time-sliced velocity map ion imaging techniques. Highly vibrationally excited naphthalene (2.0 eV vibrational energy) was formed via the rapid intersystem crossing of naphthalene initially excited to the S(2) state by 266 nm photons. The shapes of the collisional energy-transfer probability density functions were measured directly from the scattering results of highly vibrationally excited naphthalene. In comparison to Kr atoms, the energy transfer in collisions between CHF(3) and naphthalene shows more forward scatterings, larger cross section for vibrational to translational (V → T) energy transfer, smaller cross section for translational to vibrational and rotational (T → VR) energy transfer, and more energy transferred from vibration to translation, especially in the range -ΔE(d) = -100 to -800 cm(-1). On the other hand, the difference of energy transfer properties between collisional partners Kr and CF(4) is small. The enhancement of the V → T energy transfer in collisions with CHF(3) is attributed to the large attractive interaction between naphthalene and CHF(3) (1-3 kcal/mol).
Krüger, C; Lahm, T; Zugck, C; Kell, R; Schellberg, D; Schweizer, M W F; Kübler, W; Haass, M
2002-12-01
This prospective study evaluated whether heart rate variability (HRV) assessed from Holter ECG has prognostic value in addition to established parameters in patients with congestive heart failure (CHF). The study included 222 patients with CHF due to dilated or ischemic cardiomyopathy (left ventricular ejection fraction LVEF 21+/-1%; mean+/-SEM). During a mean follow-up of 15+/-1 months, 38 (17%) patients died and 45 (20%) were hospitalized due to worsening of CHF. The HRV parameter SDNN (standard deviation of all intervals between normal beats) was significantly lower in non-surviving or hospitalized than in event-free patients (118+/-6 vs 142+/-5 ms), as were LVEF (18+/-1 vs 23+/-1%), and peak oxygen uptake during exercise (peak VO(2)) (12.8+/-0.5 vs 15.6+/-0.5 ml/min/kg). While each of these parameters was a risk predictor in univariate analysis, multivariate analysis revealed that HRV provides both independent and additional prognostic information with respect to the risk 'cardiac mortality or deterioration of CHF'. It is concluded that the determination of HRV enhances the prognostic power given by the most widely used parameters LVEF and peak VO(2) in the prediction of mortality or deterioration of CHF and thus enables to improve risk stratification.
Plachi, Franciele; Balzan, Fernanda M; Sanseverino, Renata A; Palombini, Dora V; Marques, Renata D; Clausell, Nadine O; Knorst, Marli M; Neder, J Alberto; Berton, Danilo C
2018-02-21
Aim To investigate if cardiac/pulmonary functional tests and variables obtained from clinical practice (body mass index, dyspnea, functional class, clinical judgment of disability to perform an exercise test and previous hospitalization rate) are related to mortality in patients with overlap chronic obstructive pulmonary disease (COPD) and chronic heart failure (CHF). Although the coexistence of COPD and CHF has been growingly reported, description of survival predictors considering the presence of both conditions is still scarce. Using a cohort design, outpatients with the previous diagnosis of COPD and/or CHF that performed both spirometry and echocardiography in the same year were followed-up during a mean of 20.9±8.5 months. Findings Of the 550 patients initially evaluated, 301 had both spirometry and echocardiography: 160 (53%) with COPD on isolation; 100 (33%) with CHF on isolation; and 41 (14%) with overlap. All groups presented similar mortality: COPD 17/160 (11%); CHF 12/100 (12%); and overlap 7/41 (17%) (P=0.73). In the overlap group (n=41), inability to exercise and hospitalization rate were the unique parameters associated with higher mortality (seven events) in univariate analyses. In conclusion, inability to exercise and hospitalization rate emerged as the unique parameters associated with mortality in our sample.
The Performance of Short-Term Heart Rate Variability in the Detection of Congestive Heart Failure
Barros, Allan Kardec; Ohnishi, Noboru
2016-01-01
Congestive heart failure (CHF) is a cardiac disease associated with the decreasing capacity of the cardiac output. It has been shown that the CHF is the main cause of the cardiac death around the world. Some works proposed to discriminate CHF subjects from healthy subjects using either electrocardiogram (ECG) or heart rate variability (HRV) from long-term recordings. In this work, we propose an alternative framework to discriminate CHF from healthy subjects by using HRV short-term intervals based on 256 RR continuous samples. Our framework uses a matching pursuit algorithm based on Gabor functions. From the selected Gabor functions, we derived a set of features that are inputted into a hybrid framework which uses a genetic algorithm and k-nearest neighbour classifier to select a subset of features that has the best classification performance. The performance of the framework is analyzed using both Fantasia and CHF database from Physionet archives which are, respectively, composed of 40 healthy volunteers and 29 subjects. From a set of nonstandard 16 features, the proposed framework reaches an overall accuracy of 100% with five features. Our results suggest that the application of hybrid frameworks whose classifier algorithms are based on genetic algorithms has outperformed well-known classifier methods. PMID:27891509
Gschwend, S; Henning, R H; Pinto, Y M; de Zeeuw, D; van Gilst, W H; Buikema, H
2003-01-01
Increased vascular resistance in chronic heart failure (CHF) has been attributed to stimulated neurohumoral systems. However, local mechanisms may also importantly contribute to set arterial tone. Our aim, therefore, was to test whether pressure-induced myogenic constriction of resistance arteries in vitro – devoid of acute effects of circulating factors – is increased in CHF and to explore underlying mechanisms. At 12 weeks after coronary ligation-induced myocardial infarction or SHAM-operations in rats, we studied isolated mesenteric arteries for myogenic constriction, determined as the active constriction (% of passive diameter) in response to stepwise increase in intraluminal pressure (20 – 160 mmHg), in the absence and presence of inhibitors of potentially involved modulators of myogenic constriction. We found that myogenic constriction in mesenteric arteries from CHF rats was markedly increased compared to SHAM over the whole pressure range, the difference being most pronounced at 60 mmHg (24±2 versus 4±3%, respectively, P<0.001). Both removal of the endothelium as well as inhibition of NO production (L-NG-monomethylarginine, 100 μM) significantly increased myogenic constriction (+16 and +25%, respectively), the increase being similar in CHF- and SHAM-arteries (P=NS). Neither endothelin type A (ETA)-receptor blockade (BQ123, 1 μM) nor inhibition of perivascular (sympathetic) nerve conduction (tetrodotoxin, 100 nM) affected the myogenic response in either group. Interestingly, increased myogenic constriction in CHF was fully reversed after angiotensin II type I (AT1)-receptor blockade (candesartan, 100 nM; losartan, 10 μM), which was without effect in SHAM. In contrast, neither angiotensin-converting enzyme (ACE) inhibition (lisinopril, 1 μM; captopril, 10 μM) or AT2-receptor blockade (PD123319, 1 μM), nor inhibition of superoxide production (superoxide dismutase, 50 U ml−1), TXA2-receptor blockade (SQ29,548, 1 μM) or inhibition of cyclooxygenase-derived prostaglandins (indomethacin, 10 μM) affected myogenic constriction. Sensitivity of mesenteric arteries to angiotensin II (10 nM – 100 μM) was increased (P<0.05) in CHF (pD2 7.1±0.4) compared to SHAM (pD2 6.2±0.3), while the sensitivity to KCl and phenylephrine was not different. Our results demonstrate increased myogenic constriction in small mesenteric arteries of rats with CHF, potentially making it an important target for therapy in counteracting increased vascular resistance in CHF. Our results further suggest active and instantaneous participation of AT1-receptors in increased myogenic constriction in CHF, involving increased sensitivity of AT1-receptors rather than apparent ACE-mediated local angiotensin II production. PMID:12890711
Marangoni Effects on Near-Bubble Microscale Transport During Boiling of Binary Fluid Mixtures
NASA Technical Reports Server (NTRS)
V. Carey; Sun, C.; Carey, V. P.
2000-01-01
In earlier investigations, Marangoni effects were observed to be the dominant mechanism of boiling transport in 2-propanol/water mixtures under reduced gravity conditions. In this investigation we have examined the mechanisms of binary mixture boiling by exploring the transport near a single bubble generated in a binary mixture between a heated surface and cold surface. The temperature field created in the liquid around the bubble produces vaporization over the portion of its interface near the heated surface and condensation over portions of its interface near the cold surface. Experiments were conducted using different mixtures of water and 2-propanol under 1g conditions and under reduced gravity conditions aboard the KC135 aircraft. Since 2-propanol is more volatile than water, there is a lower concentration of 2-propanol near the hot surface and a higher concentration of 2-propanol near the cold plate relative to the bulk quantity. This difference in interface concentration gives rise to strong Marangoni effects that move liquid toward the hot plate in the near bubble region for 2-propanol and water mixtures. In the experiments in this study, the pressure of the test system was maintained at about 5 kPa to achieve the full spectrum of boiling behavior (nucleate boiling, critical heat flux and film boiling) at low temperature and heat flux levels. Heat transfer data and visual documentation of the bubble shape were extracted from the experimental results. In the 1-g experiments at moderate to high heat flux levels, the bubble was observed to grow into a mushroom shape with a larger top portion near the cold plate due to the buoyancy effect. The shape of the bubble was somewhat affected by the cold plate subcooling and the superheat of the heated surface. At low superheat levels for the heated surface, several active nucleation sites were observed, and the vapor stems from them merged to form a larger bubble. The generation rate of vapor is moderate in this regime and the bubble shape is cylindrical in appearance. In some instances, the bubble interface appeared to oscillate. At higher applied heat flux levels, the top of the bubble became larger, apparently to provide more condensing interface area adjacent to the cold plate. Increasing the applied heat flux ultimately led to dry-out of the heated surface, with conditions just prior to dryout corresponding to the maximum heat flux (CHF). A more stable bubble was observed when the system attained the minimum heat flux (for film boiling). In this regime, most of the surface under the bottom of the bubble was dry with nucleate boiling sometimes occuring around the contact perimeter of the bubble at heated surface. Different variations (e.g. gap between two plates, molar concentration of the liquid mixture) of the experiments were examined to determine parametric effects on the boiling process and to determine the best conditions for the KC135 reduced gravity tests. Variation of the gap was found to have a minor impact on the CHF. However, reducing the gap between the hot and cold surface was observed to significantly reduce the minimum heat flux for fixed molar concentration of 2-propanol. In the reduced gravity experiments aboard the KC135 aircraft, the bubble formed in the 6.4 mm gap was generally cylindrical or barrel shaped and it increased its extent laterally as the surface superheat increased. In reduced gravity experiments, dryout of the heated surface under the bubble was observed to occur at a lower superheated temperature than for 1g conditions. Observed features of the boiling process and heat transfer data under reduced gravity will be discussed in detail. The results of the reduced gravity experiments will also be compared to those obtained in comparable 1g experiments. In tandem with the experiments we are also developing a computational model of the transport in the liquid surrounding the bubble during the boiling process. The computational model uses a level set method to model motion of the interface. It will incorporate a macroscale treatment of the transport in the liquid gap between the surfaces and a microscale treatment of transport in the regions between the bubble interface and the solid surfaces. The features of the model will be described in detail. Future research directions suggested by the results to date will also be discussed.
De Meulenaere, Evelien; Bailey, Jake Brian; Tezcan, Faik Akif; Deheyn, Dimitri Dominique
2017-12-11
Ferritin, a multimeric cage-like enzyme, is integral to iron metabolism across all phyla through the sequestration and storage of iron through efficient ferroxidase activity. While ferritin sequences from ∼900 species have been identified, crystal structures from only 50 species have been reported, the majority from bacterial origin. We recently isolated a secreted ferritin from the marine invertebrate Chaetopterus sp. (parchment tube worm), which resides in muddy coastal seafloors. Here, we present the first ferritin from a marine invertebrate to be crystallized and its biochemical characterization. The initial ferroxidase reaction rate of recombinant Chaetopterus ferritin (ChF) is 8-fold faster than that of recombinant human heavy-chain ferritin (HuHF). To our knowledge, this protein exhibits the fastest catalytic performance ever described for a ferritin variant. In addition to the high-velocity ferroxidase activity, ChF is unique in that it is secreted by Chaetopterus in a bioluminescent mucus. Previous work has linked the availability of Fe 2+ to this long-lived bioluminescence, suggesting a potential function for the secreted ferritin. Comparative biochemical analyses indicated that both ChF and HuHF showed similar behavior toward changes in pH, temperature, and salt concentration. Comparison of their crystal structures shows no significant differences in the catalytic sites. Notable differences were found in the residues that line both 3-fold and 4-fold pores, potentially leading to increased flexibility, reduced steric hindrance, or a more efficient pathway for Fe 2+ transportation to the ferroxidase site. These suggested residues could contribute to the understanding of iron translocation through the ferritin shell to the ferroxidase site. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.
Häggström, J; Boswood, A; O'Grady, M; Jöns, O; Smith, S; Swift, S; Borgarelli, M; Gavaghan, B; Kresken, J-G; Patteson, M; Åblad, B; Bussadori, C M; Glaus, T; Kovačević, A; Rapp, M; Santilli, R A; Tidholm, A; Eriksson, A; Belanger, M C; Deinert, M; Little, C J L; Kvart, C; French, A; Rønn-Landbo, M; Wess, G; Eggertsdottir, A; Lynne O'Sullivan, M; Schneider, M; Lombard, C W; Dukes-McEwan, J; Willis, R; Louvet, A; DiFruscia, R
2013-01-01
Myxomatous mitral valve disease (MMVD) is an important cause of morbidity and mortality in dogs. To compare, throughout the period of follow-up of dogs that had not yet reached the primary endpoint, the longitudinal effects of pimobendan versus benazepril hydrochloride treatment on quality-of-life (QoL) variables, concomitant congestive heart failure (CHF) treatment, and other outcome variables in dogs suffering from CHF secondary to MMVD. A total of 260 dogs in CHF because of MMVD. A prospective single-blinded study with dogs randomized to receive pimobendan (0.4-0.6 mg/kg/day) or benazepril hydrochloride (0.25-1.0 mg/kg/day). Differences in outcome variables and time to intensification of CHF treatment were compared. A total of 124 dogs were randomized to pimobendan and 128 to benazepril. No difference was found between groups in QoL variables during the trial. Time from inclusion to 1st intensification of CHF treatment was longer in the pimobendan group (pimobendan 98 days, IQR 30-276 days versus benazepril 59 days, IQR 11-121 days; P = .0005). Postinclusion, dogs in the pimobendan group had smaller heart size based on VHS score (P = .013) and left ventricular diastolic (P = .035) and systolic (P = .0044) dimensions, higher body temperature (P = .030), serum sodium (P = .0027), and total protein (P = .0003) concentrations, and packed cell volume (P = .030). Incidence of arrhythmias was similar in treatment groups. Pimobendan versus benazepril resulted in similar QoL during the study, but conferred increased time before intensification of CHF treatment. Pimobendan treatment resulted in smaller heart size, higher body temperature, and less retention of free water. Copyright © 2013 by the American College of Veterinary Internal Medicine.
Kyrzopoulos, Stamos; Adamopoulos, Stamatis; Parissis, John T; Rassias, John; Kostakis, George; Iliodromitis, Efstathios; Degiannis, Dimitrios; Kremastinos, Dimitrios Th
2005-03-30
Plasma B-type natriuretic peptide (BNP) and interleukin 6 (IL-6) levels have recently been demonstrated as significant neurohormonal markers associated with the progression of chronic heart failure (CHF). Additionally, clinical studies have shown that the calcium sensitizer, levosimendan, beneficially affects the central hemodynamics of CHF patients and improves their long-term prognosis. This study investigates whether levosimendan-induced hemodynamic improvement of CHF patients is related to the respective changes of NT-proBNP and IL-6 levels. Circulating levels of NT-pro BNP and IL-6 were measured by enzyme-linked immunosorbent assay (ELISA) in 12 patients with decompensated advanced CHF at baseline, immediately after the end of a 24-h levosimendan infusion and 72 h after the initiation of treatment. Hemodynamic parameters of patients (pulmonary wedge and pulmonary artery pressure (PAP), systemic and pulmonary vascular resistance (PVR), stroke volume, and cardiac output and index) were also monitored during the same period. NT-proBNP and IL-6 levels were significantly reduced in severe CHF patients within 72 h after the initiation of levosimendan treatment (p<0.01 and p<0.05, respectively). A significant reduction of pulmonary wedge (p<0.01) and artery pressure values (p<0.05) was also found during the same period. A good correlation between the levosimendan-induced changes in NT-proBNP levels and the respective reduction of pulmonary wedge pressure (r(s)=0.65, p<0.05) was observed. Our results indicate that changes of NT-pro BNP and IL-6 levels may be useful biochemical markers related with the levosimendan-induced improvement in central hemodynamics and the clinical status of decompensated advanced CHF patients.
Dickson, David; Caivano, Domenico; Matos, Jose Novo; Summerfield, Nuala; Rishniw, Mark
2017-12-01
To provide reference intervals for 2-dimensional linear and area-based estimates of left atrial (LA) function in healthy dogs and to evaluate the ability of estimates of LA function to differentiate dogs with subclinical myxomatous mitral valve disease (MMVD) and similarly affected dogs with congestive heart failure (CHF). Fifty-two healthy adult dogs, 88 dogs with MMVD of varying severity. Linear and area measurements from 2-dimensional echocardiographs in both right parasternal long and short axis views optimized for the left atrium were used to derive estimates of LA active emptying fraction, passive emptying fraction, expansion index, and total fractional emptying. Differences for each estimate were compared between healthy and MMVD dogs (based on ACVIM classification), and between MMVD dogs with subclinical disease and CHF that had similar LA dimensions. Diagnostic utility at identifying CHF was examined for dogs with subclinical MMVD and CHF. Relationships with bodyweight were assessed. All estimates of LA function decreased with increasing ACVIM stage of mitral valve disease (p<0.05) and showed negative relationships with increasing LA size (all r 2 values < 0.2), except for LA passive emptying fraction, which did not differ or correlate with LA size (p=0.4). However, no index of LA function identified CHF better than measurements of LA size. Total LA fractional emptying and expansion index showed modest negative correlations with bodyweight. Estimates of LA function worsen with worsening MMVD but fail to discriminate dogs with CHF from those with subclinical MMVD any better than simple estimates of LA size. Copyright © 2017 Elsevier B.V. All rights reserved.
Borghi, Josephine; Maluka, Stephen; Kuwawenaruwa, August; Makawia, Suzan; Tantau, Juma; Mtei, Gemini; Ally, Mariam; Macha, Jane
2013-06-13
The National Health Insurance Fund (NHIF), a compulsory formal sector scheme took over the management of the Community Health Fund (CHF), a voluntary informal sector scheme, in 2009. This study assesses the origins of the reform, its effect on management and reporting structures, financial flow adequacy, reform communication and acceptability to key stakeholders, and initial progress towards universal coverage. The study relied on national data sources and an in-depth collective case study of a rural and an urban district to assess awareness and acceptability of the reform, and fund availability and use relative to need in a sample of facilities. The reform was driven by a national desire to expand coverage and increase access to services. Despite initial delays, the CHF has been embedded within the NHIF organisational structure, bringing more intensive and qualified supervision closer to the district. National CHF membership has more than doubled. However, awareness of the reform was limited below the district level due to the reform's top-down nature. The reform was generally acceptable to key stakeholders, who expected that benefits between schemes would be harmonised.The reform was unable to institute changes to the CHF design or district management structures because it has so far been unable to change CHF legislation which also limits facility capacity to use CHF revenue. Further, revenue generated is currently insufficient to offset treatment and administration costs, and the reform did not improve the revenue to cost ratio. Administrative costs are also likely to have increased as a result of the reform. Informal sector schemes can benefit from merger with formal sector schemes through improved data systems, supervision, and management support. However, effects will be maximised if legal frameworks can be harmonised early on and a reduction in administrative costs is not guaranteed.
Wang, Huan; Kwak, Dongmin; Fassett, John; Hou, Lei; Xu, Xin; Burbach, Brandon J.; Thenappan, Thenappan; Xu, Yawei; Ge, Jun-bo; Shimizu, Yoji; Bache, Robert J.; Chen, Yingjie
2017-01-01
The inflammatory response regulates congestive heart failure (CHF) development. T-cell activation plays an important role in tissue inflammation. We postulate that CD28 or B7 deficiency inhibits T-cell activation and attenuates CHF development by reducing systemic, cardiac and pulmonary inflammation. We demonstrated that chronic pressure overload-induced end-stage CHF in mice is characterized by profound accumulation of activated effector T-cells (CD3+CD44high cells) in the lungs and a mild but significant increase of these cells in the heart. In knockout (KO) mice lacking either CD28 or B7, there was a dramatic reduction in the accumulation of activated effector T cells in both hearts and lungs of mice under control conditions and after transverse aortic constriction (TAC). CD28 or B7 KO significantly attenuated TAC-induced CHF development, as indicated by less increase of heart and lung weight, and less reduction of LV contractility. CD28 or B7 KO also significantly reduced TAC-induced CD45+ leukocyte, T-cell and macrophage infiltration in hearts and lungs, lowered pro-inflammatory cytokine expression (such as TNF-α and IL-1β) in lungs. Furthermore, CD28/B7 blockade by CTLA4-Ig treatment (250μg/mouse every 3 days) attenuated TAC-induced T cell activation, LV hypertrophy, and LV dysfunction. Our data indicate that CD28/B7 deficiency inhibits activated effector T-cell accumulation, reduces myocardial and pulmonary inflammation, and attenuates the development of CHF. Our findings suggest that strategies targeting T-cell activation may be useful in treating CHF. PMID:27432861
NASA Astrophysics Data System (ADS)
Gillis, K. A.
1997-01-01
Measurements of the speed of sound in seven halogenated hydrocarbons are presented. The compounds in this study are 1-chloro-1,2,2,2-tetrafluoroethane (CHClFCF3 or HCFC-124), pentafluoroethane (CHF2 CF3 or HFC-125), 1,1,1-trifluoroethane (CF3CH3 or HFC-143a), 1,1-difluoroethane (CHF2CH3 or HFC-152a), 1,1,1,2,3,3-hexafluoropropane (CF3CHFCHF2 or HFC-236ea), 1,1,1,3,3,3-hexafluoropropane (CF3CH2CF3 or HFC-236fa), and 1,1,2,2,3-pentafluoropropane (CHF2CF2CH2F or HFC-245ca). The measurements were performed with a cylindrical resonator at temperatures between 240 and 400 K and at pressures up to 1.0 MPa. Ideal-gas heat capacities and acoustic virial coefficients were directly deduced from the data. The ideal-gas heat capacity of HFC-125 from this work differs from spectroscopic calculations by less than 0.2% over the measurement range. The coefficients for virial equations of state were obtained from the acoustic data and hard-core square-well intermolecular potentials. Gas densities that were calculated from the virial equations of state for HCFC-124 and HFC-125 differ from independent density measurements by at most 0.15%, for the ranges of temperature and pressure over which both acoustic and Burnett data exist. The uncertainties in the derived properties for the other five compounds are comparable to those for HCFC-124 and HFC-125.
Household perceptions towards a redistributive policy across health insurance funds in Tanzania.
Chomi, Eunice N; Mujinja, Phares G M; Hansen, Kristian; Kiwara, Angwara D; Enemark, Ulrika
2015-03-15
The Tanzanian health insurance system comprises multiple health insurance funds targeting different population groups but which operate in parallel, with no mechanisms for redistribution across the funds. Establishing such redistributive mechanisms requires public support, which is grounded on the level of solidarity within the country. The aim of this paper is to analyse the perceptions of CHF, NHIF and non-member households towards cross-subsidisation of the poor as an indication of the level of solidarity and acceptance of redistributive mechanisms. This study analyses data collected from a survey of 695 households relating to perceptions of household heads towards cross-subsidisation of the poor to enable them to access health services. Kruskal-Wallis test is used to compare perceptions by membership status. Generalized ordinal logistic regression models are used to identify factors associated with support for cross-subsidisation of the poor. Compared to CHF and NHIF households, non-member households expressed the highest support for subsidised CHF membership for the poor. The odds of expressing support for subsidised CHF membership are higher for NHIF households and non-member households, households that are wealthier, whose household heads have lower education levels, and have sick members. The majority of households support a partial rather than fully subsidised CHF membership for the poor and there were no significant differences by membership status. The odds of expressing willingness to contribute towards subsidised CHF membership are higher for households that are wealthier, with young household heads and have confidence in scheme management. The majority may support a redistributive policy, but there are indications that this support and willingness to contribute to its achievement are influenced by the perceived benefits, amount of subsidy considered, and trust in scheme management. These present important issues for consideration when designing redistributive policies.
Effects of chronic sugar consumption on lipid accumulation and autophagy in the skeletal muscle.
De Stefanis, Daniela; Mastrocola, Raffaella; Nigro, Debora; Costelli, Paola; Aragno, Manuela
2017-02-01
In recent years, the increasing consumption of soft drinks containing high-fructose corn syrup or sucrose has caused a rise in fructose intake, which has been related to the epidemic of metabolic diseases. As fructose and glucose intake varies in parallel, it is still unclear what the effects of the increased consumption of the two single sugars are. In the present study, the impact of chronic consumption of glucose or fructose on skeletal muscle of healthy mice was investigated. C57BL/6J male mice received water (C), 15 % fructose (ChF) or 15 % glucose (ChG) to drink for up to 7 months. Lipid metabolism and markers of inflammation and autophagy were assessed in gastrocnemius muscle. Increased body weight and gastrocnemius muscle mass, as well as circulating glucose, insulin, and lipid plasma levels were observed in sugar-drinking mice. Although triglycerides increased in the gastrocnemius muscle of both ChF and ChG mice (+32 and +26 %, vs C, respectively), intramyocellular lipids accumulated to a significantly greater extent in ChF than in ChG animals (ChF +10 % vs ChG). Such perturbations were associated with increased muscle interleukin-6 levels (threefold of C) and with the activation of autophagy, as demonstrated by the overexpression of LC3B-II (ChF, threefold and ChG, twofold of C) and beclin-1 (ChF, sevenfold and ChG, tenfold of C). The present results suggest that intramyocellular lipids and the pro-inflammatory signaling could contribute to the onset of insulin resistance and lead to the induction of autophagy, which could be an adaptive response to lipotoxicity.
Spieker, L E; Noll, G; Ruschitzka, F T; Lüscher, T F
2001-12-01
Congestive heart failure (CHF) is a disease process characterized by impaired left ventricular function, increased peripheral and pulmonary vascular resistance and reduced exercise tolerance and dyspnea. Thus, mediators involved in the control of myocardial function and vascular tone may be involved in its pathophysiology. The family of endothelins (ET) consists of four closely related peptides, ET-1, ET-2, ET-3, and ET-4, which cause vasoconstriction, cell proliferation, and myocardial effects through activation of ET(A) receptors. In contrast, endothelial ET(B) receptors mediate vasodilation via release of nitric oxide and prostacyclin. In addition, ET(B) receptors in the lung are a major pathway for the clearance of ET-1 from plasma. Thus, infusion of an ET(A) receptor antagonist into the brachial artery in healthy humans leads to vasodilation whereas infusion of an ET(B) receptor antagonist causes vasoconstriction. ET-1 plasma levels are elevated in CHF and correlate both with the hemodynamic severity and with symptoms. Plasma levels of ET-1 and its precursor, big ET-1, are strong independent predictors of death in patients after myocardial infarction and with CHF. ET-1 contributes to increased systemic and pulmonary vascular resistance, vascular dysfunction, myocardial ischemia, and renal impairment in CHF. Selective ET(A) as well as combined ET(A/B) receptor antagonists have been studied in patients with CHF showing impressive hemodynamic improvements (i.e. reduced peripheral vascular and pulmonary resistance as well as increased cardiac output). These results indicate that ET receptor antagonists indeed have a potential to improve hemodynamics, symptoms, and potentially prognosis of CHF which still carries a high mortality.
The impact of pay-for-performance on quality of care for minority patients.
Epstein, Arnold M; Jha, Ashish K; Orav, E John
2014-10-01
To determine whether racial disparities in process quality and outcomes of care change under hospital pay-for-performance. Retrospective cohort study comparing the change in racial disparities in process quality and outcomes of care between 2004 and 2008 in hospitals participating in the Premier Hospital Quality Incentive Demonstration versus control hospitals. Using patient-level Hospital Quality Alliance (HQA) data, we identified 226,096 patients in Premier hospitals, which were subject to pay-for-performance (P4P) contracts and 1,607,575 patients at control hospitals who had process of care measured during hospitalization for acute myocardial infarction (AMI), congestive heart failure (CHF), or pneumonia. We additionally identified 123,241 Medicare patients in Premier hospitals and 995,107 in controls who were hospitalized for AMI, CHF, pneumonia, or coronary artery bypass graft (CABG) surgery. We then compared HQA process quality indicators for AMI, CHF, and pneumonia between P4P and control hospitals, as well as risk-adjusted mortality rates for AMI, CHF, pneumonia, and CABG. Black patients initially had lower performance on process quality indicators in both Premier and non-Premier hospitals. The racial gap decreased over time in both groups; the reduction in the gap in Premier hospitals was greater than the gap reduction in non-Premier hospitals for AMI patients. During the study period, mortality generally decreased for blacks relative to whites for AMI, CHF, and pneumonia in both Premier and non-Premier hospitals, with the relative reduction for blacks greatest in Premier hospitals for CHF. Our results show no evidence of a deleterious impact of P4P in the Premier HQID on racial disparities in process quality or outcomes.
Subclinical hypothyroidism and survival: the effects of heart failure and race.
Rhee, Connie M; Curhan, Gary C; Alexander, Erik K; Bhan, Ishir; Brunelli, Steven M
2013-06-01
Studies examining the association between subclinical hypothyroidism and mortality have yielded conflicting results. Emerging data suggest these associations may depend upon underlying congestive heart failure (CHF) and/or race, but this has not been empirically determined. Our objective was to examine the association between subclinical hypothyroidism and hypothyroidism overall with mortality according to pre-existing CHF and race. We examined the associations of subclinical hypothyroidism (TSH higher than assay upper limit of normal; total T4 within reference) and hypothyroidism overall (TSH higher than assay upper limit of normal; total T4 below lower limit of normal or within reference) with all-cause mortality among Third National Health and Nutrition Examination Survey participants stratified by CHF and race using multivariable Cox models. To confirm whether differences between strata were statistically significant, we tested for interaction on the basis of CHF (separately) and race by likelihood ratio testing. There were 14 130 (95.0%) euthyroid controls and 749 (5.0%) participants with hypothyroidism, 691 (4.6%) of whom had subclinical disease. Subclinical hypothyroidism vs euthyroidism was associated with greater mortality in those with CHF but not in those without: adjusted hazard ratios (HRs) (95% confidence intervals [CIs]) = 1.44 (1.01-2.06) and 0.97 (0.85-1.11), respectively (P interaction = .03). Similar findings were observed for hypothyroidism overall. Hypothyroidism overall vs euthyroidism was associated with greater mortality in Black participants (HR = 1.44 [95% CI = 1.03-2.03]) but not in non-Blacks (HR = 0.95 [95% CI = 0.83-1.08]) (P interaction = .03). Among participants with CHF, subclinical hypothyroidism and hypothyroidism overall are associated with greater death risk. Additional studies are needed to confirm findings and explore possible mechanisms for the differential hypothyroidism-mortality association across race.
Schober, Karsten E; Hart, Taye M; Stern, Joshua A; Li, Xiaobai; Samii, Valerie F; Zekas, Lisa J; Scansen, Brian A; Bonagura, John D
2011-08-15
To evaluate the effects of treatment on respiratory rate, serum natriuretic peptide concentrations, and Doppler echocardiographic indices of left ventricular filling pressure in dogs with congestive heart failure (CHF) secondary to degenerative mitral valve disease (MVD) and dilated cardiomyopathy (DCM). Prospective cohort study. 63 client-owned dogs. Physical examination, thoracic radiography, analysis of natriuretic peptide concentrations, and Doppler echocardiography were performed twice, at baseline (examination 1) and 5 to 14 days later (examination 2). Home monitoring of respiratory rate was performed by the owners between examinations. In dogs with MVD, resolution of CHF was associated with a decrease in respiratory rate, serum N-terminal probrain natriuretic peptide (NT-proBNP) concentration, and diastolic functional class and an increase of the ratio of peak velocity of early diastolic transmitral flow to peak velocity of early diastolic lateral mitral annulus motion (E:Ea Lat). In dogs with DCM, resolution of CHF was associated with a decrease in respiratory rate and serum NT-proBNP concentration and significant changes in 7 Doppler echocardiographic variables, including a decrease of E:Ea Lat and the ratio of peak velocity of early diastolic transmitral flow to isovolumic relaxation time. Only respiratory rate predicted the presence of CHF at examination 2 with high accuracy. Resolution of CHF was associated with predictable changes in respiratory rate, serum NT-proBNP concentration, and selected Doppler echocardiographic variables in dogs with DCM and MVD. Home monitoring of respiratory rate was simple and was the most useful in the assessment of successful treatment of CHF.
NASA Astrophysics Data System (ADS)
Diosdado, A. Muñoz; Cruz, H. Reyes; Hernández, D. Bueno; Coyt, G. Gálvez; González, J. Arellanes
2008-08-01
Heartbeat fluctuations exhibit temporal structure with fractal and nonlinear features that reflect changes in the neuroautonomic control. In this work we have used the detrended fluctuation analysis (DFA) to analyze heartbeat (RR) intervals of 54 healthy subjects and 40 patients with congestive heart failure during 24 hours; we separate time series for sleep and wake phases. We observe long-range correlations in time series of healthy persons and CHF patients. However, the correlations for CHF patients are weaker than the correlations for healthy persons; this fact has been reported by Ashkenazy et al. [1] but with a smaller group of subjects. In time series of CHF patients there is a crossover, it means that the correlations for high and low frequencies are different, but in time series of healthy persons there are not crossovers even if they are sleeping. These crossovers are more pronounced for CHF patients in the sleep phase. We decompose the heartbeat interval time series into magnitude and sign series, we know that these kinds of signals can exhibit different time organization for the magnitude and sign and the magnitude series relates to nonlinear properties of the original time series, while the sign series relates to the linear properties. Magnitude series are long-range correlated, while the sign series are anticorrelated. Newly, the correlations for healthy persons are different that the correlations for CHF patients both for magnitude and sign time series. In the paper of Ashkenazy et al. they proposed the empirical relation: αsign≈1/2(αoriginal+αmagnitude) for the short-range regime (high frequencies), however, we have found a different relation that in our calculations is valid for short and long-range regime: αsign≈1/4(αoriginal+αmagnitude).
Dong, Aishu; Chen, Sisi; Zhu, Lianlian; Shi, Lingmin; Cai, Yueli; Zeng, Jingni; Guo, Wenjian
2017-08-01
Chronic heart failure (CHF), a major public health problem worldwide, seriously limits health-related quality of life (HRQOL). How to evaluate HRQOL in older patients with CHF remains a problem. To evaluate the reliability and validity of the Chinese version of the Medical Outcomes Study Short Form version 2 (SF-36v2) in CHF patients. From September 2012 to June 2014, we assessed QOL using the SF-36v2 in 171 aging participants with CHF in four cardiology departments. Convergent and discriminant validity, factorial validity, sensitivity among different NYHA classes and between different age groups, and reliability were determined using standard measurement methods. A total of 150 participants completed a structured questionnaire including general information and the Chinese SF-36v2; 132 questionnaires were considered valid, while 21 patients refused to take part. 25 of the 50 participants invited to complete the 2-week test-retest questionnaires returned completed questionnaires. The internal consistency reliability (Cronbach's α) of the total SF-36v2 was 0.92 (range 0.74-0.93). All hypothesized item-subscale correlations showed satisfactory convergent and discriminant validity. Sensitivity was measured in different NYHA classes and age groups. Comparison of different NYHA classes showed statistical significance, but there was no significant difference between age groups. We confirmed the SF-36v2 as a valid instrument for evaluating HRQOL Chinese CHF patients. Both reliability and validity were strongly satisfactory, but there was divergence in understanding subscales such as "social functioning" because of differing cultural background. The reliability, validity, and sensitivity of SF-36v2 in aging patients with CHF were acceptable.
NASA Astrophysics Data System (ADS)
Deviren, Bayram; Kocakaplan, Yusuf; Keskin, Mustafa; Balcılar, Mehmet; Özdemir, Zeynel Abidin; Ersoy, Ersan
2014-09-01
In this study, we analyze the Turkish Lira/US Dollar (TRY/USD), Turkish Lira/Euro (TRY/EUR), Turkish Lira/Japanese Yen (TRY/JPY) and Turkish Lira/Swiss Franc (TRY/CHF) exchange rates in the global financial crisis period to detect the bubbles and crashes in the TRY by using a mathematical methodology developed by Watanabe et al. (2007). The methodology defines the bubbles and crashes in financial market price fluctuations by considering an exponential fitting of the associated data. This methodology is applied to detect the bubbles and crashes in the TRY/USD, TRY/EUR, TRY/JPY and TRY/CHF exchange rates from January, 1, 2005 to December, 20, 2013. In this mathematical methodology, the whole period of bubbles and crashes can be determined purely from past data, and the start of bubbles and crashes can be identified even before its bursts. In this way, the periods of bubbles and crashes in the TRY/USD, TRY/EUR, TRY/JPY and TRY/CHF are determined, and the beginning and end points of these periods are detected. The results show that the crashes in the TRY/CHF exchange rate are commonly finished earlier than in the other exchange rates; hence it is probable that the crashes in the other exchange rates would be finished soon when the crashes in the TRY/CHF exchange rate ended. We also find that the periods of crashes in the TRY/EUR exchange rate take longer time than in the other exchange rates. This information can be used in risk management and/or speculative gain. The crashes' periods in the TRY/EUR and TRY/USD exchange rates are observed to be relatively longer than in the other exchange rates.
Enhanced Boiling on Micro-Configured Composite Surfaces Under Microgravity Conditions
NASA Technical Reports Server (NTRS)
Zhang, Nengli; Chai, An-Ti
1999-01-01
In order to accommodate the growing thermal management needs of future space platforms, several two-phase active thermal control systems (ATCSs) have evolved and were included in the designs of space stations. Compared to the pumped single-phase liquid loops used in the conventional Space Transportation System and Spacelab, ATCSs offer significant benefits that may be realized by adopting a two-phase fluid-loop system. Alternately, dynamic power systems (DPSs), based on the Rankine cycle, seem inevitably to be required to supply the electrical power requirements of expanding space activities. Boiling heat transfer is one of the key technologies for both ATCSs and DPSs. Nucleate boiling near critical heat flux (CHF) can transport very large thermal loads with much smaller device size and much lower pumping power. However, boiling performance deteriorates in a reduced gravity environment and operation in the CHF regime is precarious because any slight overload will cause the heat transfer to suddenly move to the film boiling regime, which in turn, will result in burnout of the heat transfer surfaces. New materials, such as micro-configured metal-graphite composites, can provide a solution for boiling enhancement. It has been shown experimentally that this type of material manifests outstanding boiling heat transfer performance and their CHF is also extended to higher values. Due to the high thermal conductivity of graphite fiber (up to 1,200 W/m-K in the fiber direction), the composite surfaces are non-isothermal during the boiling process. The composite surfaces are believed to have a much wider safe operating region (a more uniform boiling curve in the CHF regime) because non-isothermal surfaces have been found to be less sensitive to variations of wall superheat in the CHF regime. The thermocapillary forces formed by the temperature difference between the fiber tips and the metal matrix play a more important role than the buoyancy in the bubble detachment, for the bubble detachment manifests itself by a necking process which should not be weakened by reduced gravity. In addition, the composite surfaces introduce no extra pressure drop, no fouling and do not impose significant primary or maintenance costs. All of these suggest that this type of composite is an ideal material for the challenge of accounting for both reliability and economy of the relevant components applied in the ATCSs, the DPSs and other devices in future space missions. The aim of the proposed work is to experimentally investigate high nucleate pool boiling performance on a micro-configured metal-graphite composite surface and to determine the mechanisms of the nucleate boiling heat transfer both experimentally and theoretically. Freon-113 and water will be used as the test liquids to investigate wettability effects on boiling characteristics. The Cu-Gr and Al-Gr composites with various volume fractions of graphite fibers will be tested to obtain the heat transfer characteristic data in the nucleate boiling region and in the CHF regime. In the experiments, the bubble emission and coalescence processes will be recorded by a video camera with a magnifying borescope probe immersed in the working fluid. The temperature profile in the thermal boundary layer on the composite surfaces will be measured by a group of micro thermocouples consisting of four ultra fine micro thermocouples. This instrument was developed and successfully used to measure the temperature profile of evaporating liquid thin layers by the proposers in a study performed at the NASA/Lewis Research Center. A two tier model to explain the nucleate boiling process and the performance enhancement on the composite surfaces has been suggested by the authors. According to the model, the thicknesses of the microlayer and the macrolayer underneath the bubbles and mushrooms, can be estimated by the geometry of the composite surface. The experimental results will be compared to the predictions from the model, and in turn, to revise and improve it.
Metzler, Dominik; Li, Chen; Engelmann, Sebastian; ...
2016-09-08
With the increasing interest in establishing directional etching methods capable of atomic scale resolution for fabricating highly scaled electronic devices, the need for development and characterization of atomic layer etching (ALE) processes, or generally etch processes with atomic layer precision, is growing. In this work, a flux-controlled cyclic plasma process is used for etching of SiO 2 and Si at the Angstrom-level. This is based on steady-state Ar plasma, with periodic, precise injection of a fluorocarbon (FC) precursor (C 4F 8 and CHF 3), and synchronized, plasma-based Ar+ ion bombardment [D. Metzler et al., J Vac Sci Technol A 32,more » 020603 (2014), and D. Metzler et al., J Vac Sci Technol A 34, 01B101 (2016)]. For low energy Ar+ ion bombardment conditions, physical sputter rates are minimized, whereas material can be etched when FC reactants are present at the surface. This cyclic approach offers a large parameter space for process optimization. Etch depth per cycle, removal rates, and self-limitation of removal, along with material dependence of these aspects, were examined as a function of FC surface coverage, ion energy, and etch step length using in situ real time ellipsometry. The deposited FC thickness per cycle is found to have a strong impact on etch depth per cycle of SiO 2 and Si, but is limited with regard to control over material etching selectivity. Ion energy over the 20 to 30 eV range strongly impacts material selectivity. The choice of precursor can have a significant impact on the surface chemistry and chemically enhanced etching. CHF 3 has a lower FC deposition yield for both SiO 2 and Si, and also exhibits a strong substrate dependence of FC deposition yield, in contrast to C4F 8. The thickness of deposited FC layers using CHF 3 is found to be greater for Si than for SiO 2. X-ray photoelectron spectroscopy was used to study surface chemistry. When thicker FC films of 11 Å are employed, strong changes of FC film chemistry during a cycle are seen whereas the chemical state of the substrate varies much less. On the other hand, for FC film deposition of 5 Å for each cycle, strong substrate surface chemical changes are seen during an etching cycle. The nature of this cyclic etching with periodic deposition of thin FC films differs significantly from conventional etching with steady-state FC layers since surface conditions change strongly throughout each cycle.« less
A novel green approach for the preparation of cellulose nanowhiskers from white coir.
Nascimento, Diego M; Almeida, Jessica S; Dias, Amanda F; Figueirêdo, Maria Clea B; Morais, João Paulo S; Feitosa, Judith P A; de F Rosa, Morsyleide
2014-09-22
The aim of this work was to optimize the extraction of cellulose nanowhiskers (CNW) from unripe coconut husk fibers (CHF). The CHF was delignified using organosolv process, followed by alkaline bleaching (5% (w/w) H2O2+4% (w/w) NaOH; 50°C, 90 min). The CHF was subsequently hydrolyzed with 30% (v/v) sulfuric acid (60°C, 360 min). The process yielded a partially delignified acetosolv cellulose pulp and acetic black liquor, from which the lignin was recovered. The CNW from the acetosolv pulp exhibited an average length of 172±88 nm and a diameter of 8±3 nm, (aspect ratio of 22±8). The surface charge of the CNW was -33 mV, indicating a stable aqueous colloidal suspension. The nanocrystals presented physical characteristics close to those extracted from cellulose pulp made by CHF chlorine-pulping. This approach offers the additional advantage of extracting the lignin as an alternative to eradication. Copyright © 2014 Elsevier Ltd. All rights reserved.
[The proliferative characteristics of cells in culture during perfusion of the medium].
Akatov, V S; Lavrovskaia, V P; Lezhnev, E I
1991-01-01
The proliferation of Chinese hamster fibroblasts (CHF) and NIH 3T3 cells was studied at different flow rates immediately above the cells. It is shown that there is a limiting density of saturation of the perfused culture that accounts for 1.7 x 10(6) - 2.0 x 10(6) cells/cm2 for NIH 3T3 cells, and for 6 x 10(6) - 7 x 10(6) cells/cm2 for CHF. The growth curves and the distribution of cells with respect to the phases of the cell cycle during cultivation with and without perfusion are presented. Based on the results obtained it is assumed that the limit of saturation density of perfused CHF culture is due to the mass transfer of the growth-inhibiting metabolites inside the multilayer structures. The assumption seems to hold true for NIH 3T3 cells, too, even though the multilayer character of growth of this culture is less pronounced than in CHF.
Foster, Erin R.; Cunnane, Kathleen B.; Edwards, Dorothy F.; Morrison, M. Tracy; Ewald, Gregory A.; Geltman, Edward M.; Zazulia, Allyson R.
2011-01-01
OBJECTIVE We investigated participation levels and relationships among cognition, depression, and participation for people with severe congestive heart failure (CHF). METHOD People with severe CHF (New York Heart Association Class III or IV) awaiting heart transplantation (N = 27) completed standardized tests of cognition and self-report measures of executive dysfunction, depressive symptoms, and participation. RESULTS Possible depression (64%) and cognitive impairment (15%–59%) were prevalent. Participants reported significant reductions in participation across all activity domains since CHF diagnosis (ps < .001). Worse executive dysfunction and depressive symptoms were associated with reduced participation and together accounted for 35%–46% of the variance in participation (ps < .01). CONCLUSION Participation restrictions associated with CHF are not limited to physically demanding activities and are significantly associated with executive dysfunction and depression. Cardiac rehabilitation should address cognitive and psychological functioning in the context of all life situations instead of focusing solely on physical function and disability. PMID:21675336
Li, Yulong; Schultz, Harold D.; Wang, Wei-Zhong; Wang, Wei; Finch, Marcus; Smith, Lynette M.; Zucker, Irving H.
2010-01-01
Elevated central angiotensin II (ANG II) plays a critical role in the sympathoexcitation of chronic heart failure (CHF) by stimulating upregulated ANG II type 1 receptors (AT1R) in the rostral ventrolateral medulla (RVLM). However, the link between enhanced ANG II signaling and alterations in the electrophysiological characteristics of neurons in the RVLM remains unclear. In the present experiments, we screened for potentially altered genes in the medulla of rats with CHF that are directly related to neuronal membrane conductance using the Rat Genome 230 2.0 Array GeneChip. We found that CHF rats exhibited a 2.1-fold reduction in Kv4.3 gene expression, one of the main voltage-gated K+ channels, in the medulla. Real-time RT-PCR and Western blot analysis confirmed the downregulation of Kv4.3 in the RVLM of CHF rats. In intact animals, we found that microinjection of the voltage-gated potassium channel blocker, 4-aminopyridine, into the RVLM evoked a sympathoexcitation and hypertension in both normal and CHF rats. CHF rats exhibited smaller responses to 4-aminopyridine than did normal rats. Finally, we used a neuronal cell line (CATH.a neurons) to explore the effect of ANG II on Kv4.3 expression and function. We found that ANG II treatment significantly downregulated mRNA and protein expression of Kv4.3 and decreased the A-type K+ current. Employing this cell line, we also found that the ANG II-induced inhibition of Kv4.3 mRNA expression was attenuated by the superoxide scavenger Tempol and the p38 MAPK inhibitor SB-203580. The effects of ANG II were abolished by the AT1R antagonist losartan. We conclude that the sympathoexcitation observed in the CHF state may be due, in part, to an ANG II-induced downregulation of Kv4.3 expression and subsequent decrease in K+ current, thereby increasing the excitability of neurons in the RVLM. The ANG II-induced inhibition of Kv4.3 mRNA expression was mediated by ANG II-AT1R-ROS-p38 MAPK signaling. PMID:20044444
Echocardiographic evaluation of cardiac dyssynchrony in patients with congestive heart failure.
Qin, Chuan; Zhang, Li; Zhang, Zi-Ming; Wang, Bin; Ye, Zhou; Wang, Yong; Nanda, Navin C; Xie, Ming-Xing
2016-06-01
The present study investigated the application of echocardiography to evaluation of cardiac dyssynchrony in patients with congestive heart failure (CHF). A total of 348 consecutive CHF patients who were admitted for cardiac resynchronization (CRT) and presented with low ejection fraction (EF) and wide QRS duration were enrolled in this study, along with 388 healthy individuals. Dyssynchrony was assessed based on filling time ratio (FT/RR), left ventricular pre-ejection delay (PED), interventricular mechanical delay (IVMD), longitudinal opposing wall delay (LOWD) and radial septal to posterior wall delay (RSPWD). Response to CRT was defined as a ≥15% increase in EF. The results showed that FT/RR was decreased while PED, IVMD, LOWD and RSPWD were increased in the CHF group compared with the control group (P<0.01). In the CHF group, FT/RR was negatively correlated with the QRS duration, LV end-diastolic diameter (LVESd), LV end-diastolic volume (LVEDV) and LV end-systolic volume (LVESV) (P<0.01), but positively with the LVEF (P<0.01). Additionally, PED, IVMD, LOWD and RSPWD were positively correlated with the QRS duration, LVESd, LVEDV and LVESV (P<0.01), but negatively with the LVEF (P<0.01). The CHF group was divided into three subgroups according to the varying degrees of LVEF. FT/RR decreased successively from the LVEF-1 group to the LVEF-2 group to the LVEF-3 group, while the PED, IVMD, LOWD and RSPWD successively increased in the same order (P<0.01). The CHF group was divided into three subgroups according to the varying degrees of QRS duration, and FT/RR decreased successively in a sequence from the QRS-1 group to the QRS-2 group to the QRS-3 group, while the PED, IVMD, LOWD and RSPWD successively increased in the same order (P<0.01). Speckle tracking radial dyssynchrony ≥130 ms was predictive of an EF response in patients in QRS-1 group (78% sensitivity, 83% specificity), those in QRS-2 group (83% sensitivity, 77% specificity) and in QRS-3 group (89% sensitivity, 79% specificity). In conclusion, echocardiography is a convenient and sensitive method for evaluating cardiac dyssynchrony in patients with CHF.
Zhang, Han; Feng, Liu; Wan, Qi-Lin; Hong, Yan; Li, Yan-Ming; Cheng, Guan-Chang; Han, Xin-Qiang
2015-07-01
Sleep-disordered breathing (SDB) is known to occur frequently in and may predict worsening progression of patients with congestive heart failure (CHF). SDB is also known to play an important role in the development of idiopathic pulmonary arterial hypertension (PAH) via inducing endothelial dysfunction and vascular remodeling, a pathological process that can be significantly influenced by factors such as osteoprotegerin (OPG) and endothelial progenitor cells (EPCs). The objective of this study is to determine if CHF with SDB is associated with changes in OPG, EPCs, and PAH. EPCs were isolated, cultured, and quantified from CHF patients with SDB (n = 52), or without SDB (n = 68). OPG and N-terminal pro-brain natriuretic peptide (NT-proBNP) from each group was analyzed and correlated with EPCs and the mean pulmonary artery pressure (mPAP) measured by right heart catheterization. A significant decrease in circulating EPCs (29.30 ± 9.01 vs. 45.17 ± 10.51 EPCs/× 200 field; P < 0.05) was found in CHF patients with SDB compared to those without SDB. Both OPG (789.83 ± 89.38 vs. 551.29 ± 42.12 pg/mL; P < 0.05) and NT-proBNP (5946.50 ± 1434.50 vs. 3028.60 ± 811.90 ng/mL; P < 0.05) were also significantly elevated in SDB CHF patients who also had significantly elevated mPAP (50.2 ± 9.5 vs. 36.4 ± 4.1 mm Hg; P < 0.05). EPC numbers correlated inversely with the episodes of apnea and hypopnea per hour (RDI, r = -0.45, P = 0.037) and blood level of OPG (r = -0.53, P = 0.011). Although NT-proBNP was also increased significantly in patients with SDB, it had no correlation with either EPCs or RDI. SDB due to hypoxemia from decompensated CHF is associated with (1) OPG elevation, (2) EPC depletion, and (3) mPAP elevation. The inverse relationship of circulating OPG with EPCs suggests a likely mechanism for hypoxemia and OPG in the development of pulmonary vascular dysfunction via depleting EPCs, thus worsening prognosis of CHF.
Yeboah, Joseph; Rodriguez, Carlos J; Stacey, Brandon; Lima, Joao A; Liu, Songtao; Carr, J Jeffrey; Hundley, W Gregory; Herrington, David M
2012-12-04
Limited data exist on the prevalence, associations, and prognosis of individuals with asymptomatic left ventricular systolic dysfunction (ALVSD), especially in populations without previous clinical cardiovascular disease (CVD). Kaplan-Meier and Cox proportional hazard analyses were used to assess the association between ALVSD, defined as left ventricular ejection fraction <50%, and adjudicated incident congestive heart failure (CHF), all-cause mortality, and CVD events. Of 5004 participants, 112 participants had CHF, 321 had a CVD event, and 278 died after 9 years of follow-up. The overall prevalence of ALVSD was 1.7%, with a higher prevalence in blacks (2.6%). ALVSD had a worse cardiovascular risk profile and was also associated with increased risk in unadjusted and adjusted models for incident CHF (HR [hazard ratio] [95% CI {confidence interval}]: 12.0 [7.04-20.3], P<0.0001 and 8.69 [4.89-15.45], P<0.001 respectively), CVD (HR [95% CI]: 3.32 [1.98-5.58], P<0.001 and 2.21 [1.30-3.73], P=0.003 respectively), and all-cause mortality (HR [95% CI]: 3.47 [2.03-5.94], P<0.0001 and 2.00 [1.13-3.54], P=0.017, respectively). A 10% decrement in left ventricular ejection fraction at baseline was associated with an increase in risk in unadjusted and adjusted models for clinical CHF (HR [95% CI]: 2.17 [1.82-2.63], P<0.0001 and 2.13 [1.73-2.51], P<0.001, respectively) and all-cause mortality (HR [95% CI]: 1.22 [1.05-1.41], P=0.009 and 1.17 [1.00-1.36], P=0.047, respectively). Among the subset of participants with ALVSD, the left ventricular mass index was particularly informative about risk for incident CHF (c-index=0.74). ALVSD is uncommon in individuals without previous clinical CVD, but it is associated with high risk for CHF, CVD, and all-cause mortality. The left ventricular mass index had good discrimination for incident CHF in Multi-Ethnic Study of Atherosclerosis (MESA) participants with ALVSD.
Yeboah, Joseph; Rodriguez, Carlos J.; Stacey, Brandon; Lima, Joao A.; Liu, Songtao; Carr, J. Jeffrey; Hundley, W. Gregory; Herrington, David M.
2012-01-01
Background Limited data exist on the prevalence, associations and prognosis of individuals with asymptomatic left ventricular systolic dysfunction (ALVSD), especially in populations without prior clinical cardiovascular disease (CVD). Methods and Results Kaplan-Meier and Cox proportional hazard analyses were used to assess the association between ALVSD, defined as left ventricular ejection fraction less than 50%, and adjudicated incident congestive heart failure (CHF), all-cause mortality, and CVD events. Out of 5004 participants, 112 participants had CHF, 321 had a CVD event, and 278 died after 9 years of follow-up. The overall prevalence of ALVSD was 1.7%, with a higher prevalence in African Americans (2.6%). ALVSD had worse cardiovascular risk profile and was also associated with increased risk in unadjusted and adjusted models for incident CHF [HR (95%): 12.0(7.04 – 20.3), p<0.0001 and 8.69(4.89 – 15.45), p<0.001 respectively], CVD [HR (95%):3.32(1.98 -5.58), p<0.001 and 2.21(1.30 – 3.73), p=0.003 respectively] and all-cause mortality [HR(95%):3.47(2.03 – 5.94), p<0.0001 and 2.00(1.13-3.54), p=0.017 respectively]. A 10% decrement in LVEF at baseline was associated with increase in risk in unadjusted and adjusted models for clinical CHF [HR (95%CI): 2.17(1.82 -2.63), p<0.0001 and 2.13(1.73 - 2.51), p<0.001 respectively] and all-cause mortality [HR (95%CI): 1.22(1.05 – 1.41), p=0.009 and 1.17(1.00 – 1.36), p=0.047 respectively]. Among the subset of participants with ALVSD, LVMI was particularly informative about risk for incident CHF (c- index = 0.74). Conclusions ALVSD is uncommon in individuals without prior clinical CVD, but is associated with high risk for CHF, CVD, and all-cause mortality. LVMI had good discrimination for incident CHF in MESA participants with ALVSD. PMID:23124035
Evaluating patients' comprehensibility of a standardized medication plan.
Botermann, Lea; Monzel, Katharina; Krueger, Katrin; Eickhoff, Christiane; Wachter, Angelika; Kloft, Charlotte; Laufs, Ulrich; Schulz, Martin
2016-10-01
A standardized medication plan for patients has been developed and recently enacted into German law depicting all medicines taken. It can only increase medication safety if patients use and understand it. We evaluated patients' comprehensibility of the medication plan and analyzed potential variables influencing patients' understanding. The medication plan template v2.0 was first tested in N = 40 patients, and the "Evaluation Tool to test the handling of the Medication Plan" (ET-MP) was developed, rating patients' understanding from 0 to 100 %. The cut-off, distinguishing if patients understand the medication plan, was set at 90 %. The ET-MP was then applied to an amended medication plan questioning N = 40 general internal medicine (GIM) and N = 50 patients with chronic heart failure (CHF). The mean (± standard deviation (SD)) age of the study cohort was 69 ± 13 years, 47 % female. Patients took 8 ± 3 drugs chronically. The CHF patients had a lower level of education compared to the GIM group (p = 0.004). The overall ET-MP score was 82 ± 21 % (GIM 86 ± 19 %, CHF 78 ± 23 %; p = 0.16). Forty-three percent achieved a score >90 %. A moderate correlation was found between the ET-MP score and the level of education (r = 0.45) and age (r = -0.46), respectively (both p < 0.001). Cognitively impaired CHF patients (p = 0.03) and patients with advanced CHF (p = 0.006) achieved a lower ET-MP score. In the CHF cohort, signs of depression or a lower level of self-care behaviour were not associated with a lower ET-MP score. The ET-MP is suitable to explore patients' understanding of a medication plan. Less than 50 % of the patients reached a score above 90 %. Higher age and lower level of education but not the diagnosis of CHF seem to correlate with impaired understanding of the standardized medication plan. In addition to a medication plan, a significant number of patients are in need of further and continuous care to improve medication safety.
Zakharova, Liudmila; Nural-Guvener, Hikmet; Feehery, Lorraine; Popovic-Sljukic, Snjezana
2015-01-01
Cardiac c-Kit+ cells have a modest cardiogenic potential that could limit their efficacy in heart disease treatment. The present study was designed to augment the cardiogenic potential of cardiac c-Kit+ cells through class I histone deacetylase (HDAC) inhibition and evaluate their therapeutic potency in the chronic heart failure (CHF) animal model. Myocardial infarction (MI) was created by coronary artery occlusion in rats. c-Kit+ cells were treated with mocetinostat (MOCE), a specific class I HDAC inhibitor. At 3 weeks after MI, CHF animals were retrogradely infused with untreated (control) or MOCE-treated c-Kit+ cells (MOCE/c-Kit+ cells) and evaluated at 3 weeks after cell infusion. We found that class I HDAC inhibition in c-Kit+ cells elevated the level of acetylated histone H3 (AcH3) and increased AcH3 levels in the promoter regions of pluripotent and cardiac-specific genes. Epigenetic changes were accompanied by increased expression of cardiac-specific markers. Transplantation of CHF rats with either control or MOCE/c-Kit+ cells resulted in an improvement in cardiac function, retardation of CHF remodeling made evident by increased vascularization and scar size, and cardiomyocyte hypertrophy reduction. Compared with CHF infused with control cells, infusion of MOCE/c-Kit+ cells resulted in a further reduction in left ventricle end-diastolic pressure and total collagen and an increase in interleukin-6 expression. The low engraftment of infused cells suggests that paracrine effects might account for the beneficial effects of c-Kit+ cells in CHF. In conclusion, selective inhibition of class I HDACs induced expression of cardiac markers in c-Kit+ cells and partially augmented the efficacy of these cells for CHF repair. Significance The study has shown that selective class 1 histone deacetylase inhibition is sufficient to redirect c-Kit+ cells toward a cardiac fate. Epigenetically modified c-Kit+ cells improved contractile function and retarded remodeling of the congestive heart failure heart. This study provides new insights into the efficacy of cardiac c-Kit+ cells in the ischemic heart failure model. PMID:26240433
Hirai, Daniel M; Copp, Steven W; Holdsworth, Clark T; Ferguson, Scott K; McCullough, Danielle J; Behnke, Bradley J; Musch, Timothy I; Poole, David C
2014-03-01
Chronic heart failure (CHF) impairs nitric oxide (NO)-mediated regulation of skeletal muscle O2 delivery-utilization matching such that microvascular oxygenation falls faster (i.e., speeds PO2mv kinetics) during increases in metabolic demand. Conversely, exercise training improves (slows) muscle PO2mv kinetics following contractions onset in healthy young individuals via NO-dependent mechanisms. We tested the hypothesis that exercise training would improve contracting muscle microvascular oxygenation in CHF rats partly via improved NO-mediated function. CHF rats (left ventricular end-diastolic pressure = 17 ± 2 mmHg) were assigned to sedentary (n = 11) or progressive treadmill exercise training (n = 11; 5 days/wk, 6-8 wk, final workload of 60 min/day at 35 m/min; -14% grade downhill running) groups. PO2mv was measured via phosphorescence quenching in the spinotrapezius muscle at rest and during 1-Hz twitch contractions under control (Krebs-Henseleit solution), sodium nitroprusside (SNP; NO donor; 300 μM), and N(G)-nitro-l-arginine methyl ester (L-NAME, nonspecific NO synthase blockade; 1.5 mM) superfusion conditions. Exercise-trained CHF rats had greater peak oxygen uptake and spinotrapezius muscle citrate synthase activity than their sedentary counterparts (p < 0.05 for both). The overall speed of the PO2mv fall during contractions (mean response time; MRT) was slowed markedly in trained compared with sedentary CHF rats (sedentary: 20.8 ± 1.4, trained: 32.3 ± 3.0 s; p < 0.05), and the effect was not abolished by L-NAME (sedentary: 16.8 ± 1.5, trained: 31.0 ± 3.4 s; p > 0.05). Relative to control, SNP increased MRT in both groups such that trained CHF rats had slower kinetics (sedentary: 43.0 ± 6.8, trained: 55.5 ± 7.8 s; p < 0.05). Improved NO-mediated function is not obligatory for training-induced improvements in skeletal muscle microvascular oxygenation (slowed PO2mv kinetics) following contractions onset in rats with CHF.
Copp, Steven W.; Holdsworth, Clark T.; Ferguson, Scott K.; McCullough, Danielle J.; Behnke, Bradley J.; Musch, Timothy I.; Poole, David C.
2014-01-01
Chronic heart failure (CHF) impairs nitric oxide (NO)-mediated regulation of skeletal muscle O2 delivery-utilization matching such that microvascular oxygenation falls faster (i.e., speeds PO2mv kinetics) during increases in metabolic demand. Conversely, exercise training improves (slows) muscle PO2mv kinetics following contractions onset in healthy young individuals via NO-dependent mechanisms. We tested the hypothesis that exercise training would improve contracting muscle microvascular oxygenation in CHF rats partly via improved NO-mediated function. CHF rats (left ventricular end-diastolic pressure = 17 ± 2 mmHg) were assigned to sedentary (n = 11) or progressive treadmill exercise training (n = 11; 5 days/wk, 6–8 wk, final workload of 60 min/day at 35 m/min; −14% grade downhill running) groups. PO2mv was measured via phosphorescence quenching in the spinotrapezius muscle at rest and during 1-Hz twitch contractions under control (Krebs-Henseleit solution), sodium nitroprusside (SNP; NO donor; 300 μM), and NG-nitro-l-arginine methyl ester (L-NAME, nonspecific NO synthase blockade; 1.5 mM) superfusion conditions. Exercise-trained CHF rats had greater peak oxygen uptake and spinotrapezius muscle citrate synthase activity than their sedentary counterparts (p < 0.05 for both). The overall speed of the PO2mv fall during contractions (mean response time; MRT) was slowed markedly in trained compared with sedentary CHF rats (sedentary: 20.8 ± 1.4, trained: 32.3 ± 3.0 s; p < 0.05), and the effect was not abolished by L-NAME (sedentary: 16.8 ± 1.5, trained: 31.0 ± 3.4 s; p > 0.05). Relative to control, SNP increased MRT in both groups such that trained CHF rats had slower kinetics (sedentary: 43.0 ± 6.8, trained: 55.5 ± 7.8 s; p < 0.05). Improved NO-mediated function is not obligatory for training-induced improvements in skeletal muscle microvascular oxygenation (slowed PO2mv kinetics) following contractions onset in rats with CHF. PMID:24414070
Anger and depression predict hospital use among chronic heart failure patients.
Jenner, Roslyn C; Strodl, Esben S; Schweitzer, Robert D
2009-11-01
Costly hospital readmissions among chronic heart failure (CHF) patients are expected to increase dramatically with the ageing population. This study investigated the prognostic ability of depression, anger and anxiety, prospectively, and after adjusting for illness severity, on the number of readmissions to hospital and the total length of stay over one year. Participants comprised 175 inpatients with CHF. Depression, anger, anxiety, and illness severity were measured at baseline. One year later, the number of readmissions and length of stay for each patient were obtained from medical records. Depression and anger play a detrimental role in the health profile of CHF patients.
DM programs take different roads to CHF success.
2001-02-01
Improving CHF outcomes: There's no single right way. But there are some elements in common, as suggested by the experience of Duke, Kaiser Permanente, and First Priority Health. The challenge is to identify high-risk patients and provide as comprehensive an array of services as possible.
[The German National Disease Management Guideline "Chronic Heart Failure"].
Weinbrenner, S; Langer, T; Scherer, M; Störk, S; Ertl, G; Muth, Ch; Hoppe, U C; Kopp, I; Ollenschläger, G
2012-02-01
Chronic heart failure (CHF) is an illness mostly affecting elderly people. In Germany CHF is one of the most common causes of death and at the same time one of the most common diagnosis in inpatient care. Due to the expected increase in life expectancy in the next few years experts predict a further step-up of the incidence. Against this background development of a national guideline on chronic heart failure was prioritised and accordingly the National Disease Management Guideline (NDMG) Chronic Heart Failure was developed by a multi- and interdisciplinary group. The guideline group comprised experts from all relevant scientific medical societies as well as a patient expert. The National Disease Management Guideline (NDMG) on Chronic Heart Failure aims at supporting patients and health care providers with respect to decisions on a specific health care problem by giving recommendations for actions. Recommendations are informed by the best available scientific evidence on this topic.Patients with CHF often suffer from multiple conditions. Due to this fact and the old age patients do have very complex and demanding health care needs. Thus accounting for co-morbidities is paramount in planning and providing health care for theses patients and communication between doctor and patient but also between all health care providers is crucial.Basic treatment strategies in chronic heart failure comprise management of risk factors and prognostic factors as well as appropriate consideration of co-morbidities accompanied by measures empowering patients in establishing a healthy life style and a self-dependant management of their illness.Psycho-social aspects have a very strong influence on patients' acceptance of the disease and their self-management. In addition they have a strong influence on therapy management of the treating physician thus they have to be addressed adequately during the consultation.The National Disease Management Guideline (NDMG) Chronic Heart Failure (CHF) is an interdisciplinary guideline putting particular emphasis on giving recommendations for health care management at the interfaces of the health care system. The NDMG CHF provides a collection of evidence-based and consensus-based recommendations for diagnostics and therapy of patients with CHF. This CPG is meant to improve health care for all affected patients regardless of stage of disease or health care setting. Quality improvement though can only happen when the NDMG CHF is adopted into daily routine. To support implementation a patient version of the guideline was developed. The article compiles the most relevant recommendations and algorithms of the National Disease Management Guideline (NDMG) Chronic Heart Failure (CHF). © Georg Thieme Verlag KG Stuttgart · New York.
Transcardiac increase in norepinephrine and prognosis in patients with chronic heart failure.
Tsutamoto, Takayoshi; Nishiyama, Keizo; Sakai, Hiroshi; Tanaka, Toshinari; Fujii, Masanori; Yamamoto, Takashi; Yamaji, Masayuki; Horie, Minoru
2008-12-01
No previous study has compared the transcardiac gradient of norepinephrine (NE) and the prognosis of patients with chronic heart failure (CHF). To evaluate the prognostic role of the transcardiac gradient of NE in patients with CHF. We measured haemodynamic parameters and plasma levels of NE, brain natriuretic peptide (BNP) and N-terminal proBNP (NT-proBNP) in the aortic root (AO) and coronary sinus (CS) in 356 consecutive patients with CHF. During a median follow-up of 3.5 years, 40 patients died. Transcardiac gradients of BNP (273+/-276 vs. 472+/-433 pg/mL, p<0.0001), NT-proBNP (417+/-700 vs. 928+/-1093 pg/mL, p<0.0001) and NE (114+/-160 vs. 473+/-992 pg/mL, p<0.0001) were significantly higher in non-survivors than survivors. After adjustment for clinical variables associated with CHF including haemodynamics and neurohumoral factors, the transcardiac gradient of NE (p<0.0001) and plasma log NT-proBNP (p<0.0001) were independent prognostic predictors. Among 67 patients in whom 123I-metaiodobenzylguanidine (MIBG) could be performed, transcardiac increase in NE was correlated with the washout rate (r=0.398, p=0.0009) and was a superior predictor of mortality than MIBG parameters on stepwise multivariable Cox proportional hazards regression analyses. The transcardiac increase in NE is an independent and useful prognostic predictor for evaluating the prognosis of CHF patients.
Plasma level of cardiotrophin-1 as a prognostic predictor in patients with chronic heart failure.
Tsutamoto, Takayoshi; Asai, Shigeru; Tanaka, Toshinari; Sakai, Hiroshi; Nishiyama, Keizo; Fujii, Masanori; Yamamoto, Takashi; Ohnishi, Masato; Wada, Atsuyuki; Saito, Yoshihiko; Horie, Minoru
2007-10-01
Cardiotrophin-1 (CT-1) is a member of the interleukin (IL-6) family of cytokines and is increased in patients with chronic heart failure (CHF). To evaluate the prognostic role of CT-1 in patients with CHF. We measured the plasma levels of CT-1, brain natriuretic peptide (BNP), and IL-6 in 125 patients with CHF. Patients were monitored for a mean follow-up period of 2.9 years. Plasma levels of CT-1 increased with severity of CHF. There was a significant negative correlation between plasma CT-1 and left ventricular ejection fraction. There was a significant correlation between plasma CT-1 and log IL-6. During the follow-up period, 37 patients died. High plasma levels of CT-1, BNP, and IL-6 were independent predictors of mortality on stepwise multivariate analysis. The hazard ratio for mortality in patients with plasma BNP>170 pg/mL and CT-1>658 fmol/mL was 2.48 (95% confidence interval, 1.217-5.060) compared to those with plasma BNP>170 pg/mL and CT-1<658 fmol/mL (p=0.0124). These findings indicate that plasma CT-1 measurement provides additional prognostic information and that combined levels of CT-1 and BNP are more accurate at predicting mortality in patients with CHF than either marker alone.
Jia, Peng; Xierali, Imam M
2015-09-17
Congestive heart failure (CHF) is a major public health problem in the United States and is a leading cause of hospitalization in the elderly population. Understanding the health care travel patterns of CHF patients and their underlying cause is important to balance the supply and demand for local hospital resources. This article explores the nonclinical factors that prompt CHF patients to seek distant instead of local hospitalization. Local hospitalization was defined as inpatients staying within hospital service areas, and distant hospitalization was defined as inpatients traveling outside hospital service areas, based on individual hospital discharge data in 2011 generated by a Dartmouth-Swiss hybrid approach. Multiple logistic and linear regression models were used to compare the travel patterns of different groups of inpatients in Florida. Black patients, no-charge patients, patients living in large metropolitan areas, and patients with a low socioeconomic status were more likely to seek local hospitalization than were white patients, those who were privately insured, those who lived in rural areas, and those with a high socioeconomic status, respectively. Findings indicate that different populations diagnosed with CHF had different travel patterns for hospitalization. Changes or disruptions in local hospital supply could differentially affect different groups in a population. Policy makers could target efforts to CHF patients who are less likely to travel to seek treatment.
Takahashi, Tetsuya; Watanabe, Tetsu; Shishido, Tetsuro; Watanabe, Ken; Sugai, Takayuki; Toshima, Taku; Kinoshita, Daisuke; Yokoyama, Miyuki; Tamura, Harutoshi; Nishiyama, Satoshi; Arimoto, Takanori; Takahashi, Hiroki; Yamanaka, Tamon; Miyamoto, Takuya; Kubota, Isao
2018-07-01
Liver abnormalities have a strong impact on clinical outcomes in patients with heart failure (HF), and are known as cardio-hepatic syndrome. The non-alcoholic fatty liver disease (NAFLD) fibrosis score (NFS) has been developed to identify liver fibrosis in patients with NAFLD. It remains to be determined whether NFS is associated with cardiovascular prognosis in patients with chronic heart failure (CHF). We calculated NFS in 516 patients with CHF admitted to our hospital. The clinical endpoints were deaths due to progressive HF, myocardial infarction, stroke, and sudden cardiac death, and rehospitalization for worsening HF. There were 173 cardiovascular events noted during a median follow-up of 464 days. Patients with cardiovascular events showed a higher NFS as compared with those without. We divided the patients into four groups according to quartiles of NFS. The proportion of New York Heart Association functional class III/IV and serum brain natriuretic peptide levels were increased with increasing NFS. Kaplan-Meier analysis revealed that cardiovascular event rate was increased with increasing NFS in patients with CHF. In multivariate Cox proportional hazards analysis, NFS was independently associated with cardiovascular events after adjustment for confounding factors. Elevated NFS was associated with unfavorable outcomes in patients with CHF. Liver fibrosis assessed by NFS may provide valuable prognostic information in patients with CHF.
Nelson, O. Lynne; Wood, Rachael M.; Häggström, Jens; Kvart, Clarence; Robbins, Charles T.
2017-01-01
Adiponectin is the most abundant plasma adipokine, and is well known for its role in energy homeostasis and cardiac protection. In humans with dilated cardiomyopathy, myocardial adiponectin protein expression is reduced compared to normal hearts and has been implicated in the pathology of cardiomyopathy. Serum adiponectin levels are often conflicting, with higher levels associated with poor survival in humans with congestive heart failure (CHF). We evaluated adiponectin serum concentrations and myocardial protein expression in dogs with naturally occurring myxomatous mitral valve disease and CHF. We compared the findings to active and hibernating brown bears as bears are adapted to endure an extreme period of low cardiac output during their annual hibernation. Bears exhibited largely the active high-molecular weight (HMW) versus the low-molecular weight isoforms of myocardial adiponectin (HMW:LMW = 6.3) during both the active period and hibernation, while healthy dogs exhibited a more balanced mix of isoforms. Dogs with CHF expressed predominately HMW isoforms of adiponectin (HMW:LMW = 12.5), appearing more similar to bears. In contrast to humans, serum adiponectin was significantly lower in dogs with CHF and lowest levels in the severest CHF class. In both dogs and bears, myocardial adiponectin was expressed independent of circulating adiponectin concentrations, suggesting a local regulatory mechanism within the heart. PMID:29056695
Otaki, Yoichiro; Watanabe, Tetsu; Takahashi, Hiroki; Funayama, Akira; Kinoshita, Daisuke; Yokoyama, Miyuki; Takahashi, Tetsuya; Nishiyama, Satoshi; Arimoto, Takanori; Shishido, Tetsuro; Miyamoto, Takuya; Konta, Tsuneo; Kubota, Isao
2016-02-01
Renal tubular damage (RTD) and hypoalbuminemia are risks for poor prognosis in patients with chronic heart failure (CHF). Renal tubules play a pivotal role in amino acid and albumin reabsorption, which maintain serum albumin levels. The aims of the present study were to (1) examine the association of RTD with hypoalbuminemia, and (2) assess the prognostic importance of comorbid RTD and hypoalbuminemia in patients with CHF. We measured N-acetyl-β-D-glucosamidase (NAG) levels and the urinary β2-microglobulin to creatinine ratio (UBCR) in 456 patients with CHF. RTD was defined as UBCR ≥ 300 μg/g or NAG ≥ 14.2 U/g. There were moderate correlations between RTD markers and serum albumin (NAG, r = -0.428, P < 0.0001; UBCR, r = -0.399, P < 0.0001). Multivariate logistic analysis showed that RTD was significantly related to hypoalbuminemia in patients with CHF. There were 134 cardiac events during a median period of 808 days. The comorbidity of RTD and hypoalbuminemia was increased with advancing New York Heart Association functional class. Multivariate Cox proportional hazard regression analysis showed that the presence of RTD and hypoalbuminemia was associated with cardiac events. The net reclassification index was significantly improved by adding RTD and hypoalbuminemia to the basic risk factors. Comorbid RTD and hypoalbuminemia are frequently observed and increase the risk for extremely poor outcome in patients with CHF.
Xierali, Imam M.
2015-01-01
Introduction Congestive heart failure (CHF) is a major public health problem in the United States and is a leading cause of hospitalization in the elderly population. Understanding the health care travel patterns of CHF patients and their underlying cause is important to balance the supply and demand for local hospital resources. This article explores the nonclinical factors that prompt CHF patients to seek distant instead of local hospitalization. Methods Local hospitalization was defined as inpatients staying within hospital service areas, and distant hospitalization was defined as inpatients traveling outside hospital service areas, based on individual hospital discharge data in 2011 generated by a Dartmouth–Swiss hybrid approach. Multiple logistic and linear regression models were used to compare the travel patterns of different groups of inpatients in Florida. Results Black patients, no-charge patients, patients living in large metropolitan areas, and patients with a low socioeconomic status were more likely to seek local hospitalization than were white patients, those who were privately insured, those who lived in rural areas, and those with a high socioeconomic status, respectively. Conclusion Findings indicate that different populations diagnosed with CHF had different travel patterns for hospitalization. Changes or disruptions in local hospital supply could differentially affect different groups in a population. Policy makers could target efforts to CHF patients who are less likely to travel to seek treatment. PMID:26378896
New insights into the burden and costs of multiple sclerosis in Europe: Results for Switzerland.
Calabrese, Pasquale; Kobelt, Gisela; Berg, Jenny; Capsa, Daniela; Eriksson, Jennifer
2017-08-01
To estimate the value of interventions in multiple sclerosis (MS) - where lifetime costs and outcomes cannot be observed - outcome data have to be combined with costs. This requires that cost data be regularly updated. This study is part of a cross-sectional retrospective study in 16 countries collecting data on resource consumption and work capacity, health-related quality of life (HRQoL) and prevalent symptoms for patients with MS. Descriptive analyses are presented by level of severity, from the societal perspective, in CHF 2015. A total of 721 patients (mean age 48 years) participated in Switzerland; 90% were below retirement age, and of these, 65% were employed. Employment was related to disease severity, and MS affected productivity at work for 69% of patients. Overall, 93% and 64% of patients experienced fatigue and cognition as a problem, respectively. The mean utility and annual costs were 0.799 and 29,600CHF at Expanded Disability Status Scale (EDSS) 0-3, 0.614 and 66,800CHF at EDSS 4-6.5 and 0.348 and 110,800CHF at EDSS 7-9, respectively. The mean cost of a relapse was estimated at 7600CHF. This study provides current data on MS in Switzerland that are important for development of health policies and to estimate the value of current and future treatments.
BRIEF REPORT: β-Blocker Use Among Veterans with Systolic Heart Failure
Sinha, Sanjai; Goldstein, Matthew; Penrod, Joan; Hochman, Tsivia; Kamran, Mohammad; Tenner, Craig; Cohen, Gabriela; Schwartz, Mark D
2006-01-01
BACKGROUND β-Blockers reduce mortality in patients with systolic chronic heart failure (CHF), yet prescription rates have remained low among primary care providers. OBJECTIVE To determine the β-blocker prescription rate among patients with systolic CHF at primary care Veterans Affairs (VA) clinics, its change over time; and to determine factors associated with nonprescription. DESIGN Retrospective chart review. SUBJECTS Seven hundred and forty-five patients with diagnostic codes for CHF followed in primary care clinics at 3 urban VA Medical Centers. MEASUREMENTS Rate of β-blocker prescription and comparison of patient characteristics between those prescribed versus those not prescribed β-blockers. RESULTS Only 368 (49%) had documented systolic CHF. Eighty-two percent (303/368) of these patients were prescribed a β-blocker. The prescription rate rose steadily over 3 consecutive 2-year time periods. Patients with more severely depressed ejection fractions were more likely to be on a β-blocker than patients with less severe disease. Independent predictors of nonprescription included chronic obstructive pulmonary disease, asthma, depression, and age. Patients under 65 years old were 12 times more likely to receive β-blockers than those over 85. CONCLUSION Primary care providers at VA Medical Centers achieved high rates of β-blocker prescription for CHF patients. Subgroups with relative contraindications had lower prescription rates and should be targeted for quality improvement initiatives. PMID:17105526
Miyata, Makiko; Yoshihisa, Akiomi; Suzuki, Satoshi; Yamada, Shinya; Kamioka, Masashi; Kamiyama, Yoshiyuki; Yamaki, Takayoshi; Sugimoto, Koichi; Kunii, Hiroyuki; Nakazato, Kazuhiko; Suzuki, Hitoshi; Saitoh, Shu-ichi; Takeishi, Yasuchika
2012-09-01
Cheyne-Stokes respiration (CSR-CSA) is often observed in patients with chronic heart failure (CHF). Although cardiac resynchronization therapy (CRT) is effective for CHF patients with left ventricular dyssynchrony, it is still unclear whether adaptive servo ventilation (ASV) improves cardiac function and prognosis of CHF patients with CSR-CSA after CRT. Twenty two patients with CHF and CSR-CSA after CRT defibrillator (CRTD) implantation were enrolled in the present study and randomly assigned into two groups: 11 patients treated with ASV (ASV group) and 11 patients treated without ASV (non-ASV group). Measurement of plasma B-type natriuretic peptide (BNP) levels (before 3, and 6 months later) and echocardiography (before and 6 months) were performed in each group. Patients were followed up to register cardiac events (cardiac death and re-hospitalization) after discharge. In the ASV group, indices for apnea-hypopnea, central apnea, and oxyhemoglobin saturation were improved on ASV. BNP levels, cardiac systolic and diastolic function were improved with ASV treatment for 6 months. Importantly, the event-free rate was significantly higher in the ASV group than in the non-ASV group. ASV improves CSR-CSA, cardiac function, and prognosis in CHF patients with CRTD. Patients with CSR-CSA and post CRTD implantation would get benefits by treatment with ASV. Copyright © 2012 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.
Asymmetric acceleration/deceleration dynamics in heart rate variability
NASA Astrophysics Data System (ADS)
Alvarez-Ramirez, J.; Echeverria, J. C.; Meraz, M.; Rodriguez, E.
2017-08-01
The heart rate variability (HRV) is an important physiological signal used either to assess the risk of cardiac death or to model the cardiovascular regulatory dynamics. Asymmetries in HRV data have been observed using 2D Poincare plots, which have been linked to a non-equilibrium operation of the cardiac autonomic system. This work further explores the presence of asymmetries but in the serial correlations of the dynamics of HRV data. To this end, detrended fluctuation analysis (DFA) was used to estimate the Hurst exponent both when the heart rate is accelerating and when it is decelerating. The analysis is conducted using data collected from subjects under normal sinus rhythm (NSR), congestive heart failure (CHF) and atrial fibrillation (AF) . For the NSR cases, it was found that correlations are stronger (p < 0 . 05) when the heart rate is accelerating than when it is decelerating over different scales in the range 20-40 beats. In contrast, the opposite behavior was detected for the CHF and AF patients. Possible links between asymmetric correlations in the dynamics and the mechanisms controlling the operation of the heart rate are discussed, as well as their implications for modeling the cardiovascular regulatory dynamics.
Length Scale and Gravity Effects on Microgravity Boiling Heat Transfer
NASA Technical Reports Server (NTRS)
Kim, Jungho; McQuillen, John; Balombin, Joe
2002-01-01
Boiling is a complex phenomenon where hydrodynamics, heat transfer, mass transfer, and interfacial phenomena are tightly interwoven. An understanding of boiling and critical heat flux in microgravity environments is of importance to space based hardware and processes such as heat exchange, cryogenic fuel storage and transportation, electronic cooling, and material processing due to the large amounts of heat that can be removed with relatively little increase in temperature. Although research in this area has been performed in the past four decades, the mechanisms by which heat is removed from surfaces in microgravity are still unclear. In earth gravity, buoyancy is an important parameter that affects boiling heat transfer through the rate at which bubbles are removed from the surface. A simple model describing the bubble departure size based on a quasistatic force balance between buoyancy and surface tension is given by the Fritz [I] relation: Bo(exp 1/2) = 0.0208 theta where Bo is the ratio between buoyancy and surface tension forces. For small, rapidly growing bubbles, inertia associated with the induced liquid motion can also cause bubble departure. In microgravity, the magnitude of effects related to natural convection and buoyancy are small and physical mechanisms normally masked by natural convection in earth gravity such as Marangoni convection can substantially influence the boiling and vapor bubble dynamics. CHF (critical heat transfer) is also substantially affected by microgravity. In 1 g environments, Bo has been used as a correlating parameter for CHF. Zuber's CHF model for an infinite horizontal surface assumes that vapor columns formed by the merger of bubbles become unstable due to a Helmholtz instability blocking the supply of liquid to the surface. The jets are spaced lambda(sub D) apart, where lambda(sub D) = 2pi square root of 3[(sigma)/(g(rho(sub l) - rho(sub v)](exp 1/2) = 2pi square root of 3 L Bo(exp -1/2) = square root of 3 lambda(sub c) and is the wavelength that amplifies most rapidly. The critical wavelength, lambda(sub c), is the wavelength below which a vapor layer underneath a liquid layer is stable. For heaters with Bo smaller than about 3 (heaters smaller than lambda(sub D)), the above model is not applicable, and surface tension effects dominate. Bubble coalescence is thought to be the mechanism for CHF under these conditions. Small Bo can result by decreasing the size of a heater in earth gravity, or by operating a large heater in a lower gravity environment. In the microgravity of space, even large heaters can have low Bo, and models based on Helmholtz instability should not be applicable. The macrolayer model of Haramura and Katto is dimensionally equivalent to Zuber's model and has the same dependence on gravity, so it should not be applicable as well. The goal of this work is to determine how boiling heat transfer mechanisms in a low-g environment are altered from those at higher gravity levels. Boiling data using a microheater array was obtained under gravity environments ranging from 1.8 g to 0.02 g with heater sizes ranging from 2.7 mm to 1 mm. The boiling behavior for 2.7 mm at 0.02 g looked quite similar to boiling on the 1 mm heater at 1 g-the formation of a large primary bubble surrounded by smaller satellite bubbles was observed under both conditions. The similarity suggests that for heaters smaller than some fraction of I(sub c), coalescence and surface tension dominate boiling heat transfer. It also suggests that microgravity boiling can be studied by studying boiling on very small heaters.
Jingzhi Zhang; Feng Gu; J.Y. Zhu; Ronald S. Zalesny Jr.
2015-01-01
Sulfite pretreatment to overcome the recalcitrance of lignocelluloses (SPORL) was applied to poplar NE222 chips in a range of chemical loadings, temperatures, and times. The combined hydrolysis factor (CHF) as a pretreatment severity accurately predicted xylan dissolution by SPORL. Good correlations between CHF and pretreated...
Multifractal analysis and the NYHA index
NASA Astrophysics Data System (ADS)
Muñoz-Diosdado, A.; Ramírez-Hernández, L.; Aguilar-Molina, A. M.; Zamora-Justo, J. A.; Gutiérrez-Calleja, R. A.; Virgilio-González, C. D.
2014-11-01
We did multifractal analysis of heartbeat interval time series of healthy persons and patients with congestive heart failure (CHF). To analyze circadian rhythm variations we analyzed time series of 24 hours records and segments of six hours when the subject is asleep and segments of six hours when is awake. A decrease in the multifractality degree occurs in the heartbeat interval time series of CHF patients. This multifractality loss is associated with the width reduction of the spectrum and the complexity loss of the signal. Multifractal spectra of healthy persons are right skewed, but the spectra of CHF patients tend to be symmetrical and in some cases are left skewed. To determine the therapy for CHF patients, cardiologists use an index proposed by the NYHA (New York Heart Association). There is a correlation between this index and the multifractal analysis parameters, i.e. while higher is the NYHA index the width of the multifractal spectrum is lower and it is also more symmetrical. In contrast, patients with NYHA index equal to 1 have multifractal parameters similar to those of healthy subjects.
Entropy information of heart rate variability and its power spectrum during day and night
NASA Astrophysics Data System (ADS)
Jin, Li; Jun, Wang
2013-07-01
Physiologic systems generate complex fluctuations in their output signals that reflect the underlying dynamics. We employed the base-scale entropy method and the power spectral analysis to study the 24 hours heart rate variability (HRV) signals. The results show that such profound circadian-, age- and pathologic-dependent changes are accompanied by changes in base-scale entropy and power spectral distribution. Moreover, the base-scale entropy changes reflect the corresponding changes in the autonomic nerve outflow. With the suppression of the vagal tone and dominance of the sympathetic tone in congestive heart failure (CHF) subjects, there is more variability in the date fluctuation mode. So the higher base-scale entropy belongs to CHF subjects. With the decrease of the sympathetic tone and the respiratory frequency (RSA) becoming more pronounced with slower breathing during sleeping, the base-scale entropy drops in CHF subjects. The HRV series of the two healthy groups have the same diurnal/nocturnal trend as the CHF series. The fluctuation dynamics trend of data in the three groups can be described as “HF effect”.
de Madron, Eric; King, Jonathan N; Strehlau, Günther; White, Regina Valle
2011-11-01
This retrospective study reports the survival time [onset of congestive heart failure (CHF) to death from any cause] of 21 dogs with mitral regurgitation (MR) and CHF treated with a combination of furosemide, angiotensin-converting enzyme inhibitor (ACEI, benazepril, or enalapril), pimobendan, spironolactone, and amlodipine. Baseline echocardiographic data: end-systolic and end-diastolic volume indices (ESVI and EDVI), left atrium to aorta ratio (LA/Ao), and regurgitant fraction (RF) are reported. Median survival time (MST) was 430 d. Initial dosage of furosemide (P = 0.0081) and LA/Ao (P = 0.042) were negatively associated with survival. Baseline echocardiographic indices (mean ± standard deviation) were 40.24 ± 16.76 for ESVI, 161.48 ± 44.49 mL/m(2) for EDVI, 2.11 ± 0.75 for LA/Ao, and 64.71 ± 16.85% for RF. Combining furosemide, ACEI, pimobendan, spironolactone, and amlodipine may result in long survival times in dogs with MR and CHF. Severity of MR at onset of CHF is at least moderate.
de Madron, Eric; King, Jonathan N.; Strehlau, Günther; White, Regina Valle
2011-01-01
This retrospective study reports the survival time [onset of congestive heart failure (CHF) to death from any cause] of 21 dogs with mitral regurgitation (MR) and CHF treated with a combination of furosemide, angiotensin-converting enzyme inhibitor (ACEI, benazepril, or enalapril), pimobendan, spironolactone, and amlodipine. Baseline echocardiographic data: end-systolic and end-diastolic volume indices (ESVI and EDVI), left atrium to aorta ratio (LA/Ao), and regurgitant fraction (RF) are reported. Median survival time (MST) was 430 d. Initial dosage of furosemide (P = 0.0081) and LA/Ao (P = 0.042) were negatively associated with survival. Baseline echocardiographic indices (mean ± standard deviation) were 40.24 ± 16.76 for ESVI, 161.48 ± 44.49 mL/m2 for EDVI, 2.11 ± 0.75 for LA/Ao, and 64.71 ± 16.85% for RF. Combining furosemide, ACEI, pimobendan, spironolactone, and amlodipine may result in long survival times in dogs with MR and CHF. Severity of MR at onset of CHF is at least moderate. PMID:22547843
Houchen, Linzy; Watt, Amye; Boyce, Sally; Singh, Sally
2012-07-01
People with chronic heart failure (CHF) experience acute exacerbations of their symptoms. These episodes are costly to patients and the health service. The study was a single group, pretest and posttest design. Seventeen patients with left ventricular systolic dysfunction (LVSD) started rehabilitation within 4 weeks of hospital discharge. The 6 week rehabilitation programme included exercise and self-management education. The hospital anxiety and depression scale (HADS), the incremental and endurance shuttle walking tests (ISWT/ESWT) were assessed at baseline and after rehabilitation. The number and duration of any CHF admissions in the year before and the year after rehabilitation were also recorded. Improvements in the ISWT, ESWT, and depression were, mean (95% confidence interval [CI]) 60.6 (36.0-85.2) metres, 356.0 (173.0-539.0) seconds (both p≤0.001) and (-)1.0 ((-)1.8-(-)0.2) points (p<0.05), respectively. HADS anxiety improvements failed to reach significance. At 1 year, there was a significant decrease in CHF-related hospitalisations, mean change (95% CI) (-)0.8 ((-)1.1-(-)0.4), p≤0.001 and CHF bed days (-)13.0 ((-)24.4-(-)1.6), p<0.05. Early rehabilitation significantly improved exercise capacity and depression and reduced CHF-associated health care utilisation in patients who had recently been hospitalised. The intervention was safe. However, the sample size was small and results were not compared to a control group. Therefore, the effects of natural recovery are unknown.
vanVonno, Catherine J; Ozminkowski, Ronald J; Smith, Mark W; Thomas, Eileen G; Kelley, Doniece; Goetzel, Ron; Berg, Gregory D; Jain, Susheel K; Walker, David R
2005-12-01
In 1999, the Blue Cross and Blue Shield Federal Employee Program (FEP) implemented a pilot disease management program to manage congestive heart failure (CHF) among members. The purpose of this project was to estimate the financial return on investment in the pilot CHF program, prior to a full program rollout. A cohort of 457 participants from the state of Maryland was matched to a cohort of 803 nonparticipants from a neighboring state where the CHF program was not offered. Each cohort was followed for 12 months before the program began and 12 months afterward. The outcome measures of primary interest were the differences over time in medical care expenditures paid by FEP and by all payers. Independent variables included indicators of program participation, type of heart disease, comorbidity measures, and demographics. From the perspective of the funding organization (FEP), the estimated return on investment for the pilot CHF disease management program was a savings of $1.08 in medical expenditure for every dollar spent on the program. Adding savings to other payers as well, the return on investment was a savings of $1.15 in medical expenditures per dollar spent on the program. The amount of savings depended upon CHF risk levels. The value of a pilot initiative and evaluation is that lessons for larger-scale efforts can be learned prior to full-scale rollout.
Hou, Mingxiao; Hu, Qingsong; Chen, Yingjie; Zhao, Lin; Zhang, Jianyi; Bache, Robert J
2006-11-01
We investigated whether xanthine oxidase inhibition with febuxostat enhances left ventricular (LV) function and improves myocardial high energy phosphates (HEP) in dogs with pacing-induced heart failure (CHF). Febuxostat (2.2 mg/kg over 10 minutes followed by 0.06 mg/kg/min) caused no change of LV function or myocardial oxygen consumption (MVO2) at rest or during treadmill exercise in normal dogs. In dogs with CHF, febuxostat increased LV dP/dtmax at rest and during heavy exercise (P < 0.05), indicating improved LV function with no change of MVO2. Myocardial adenosine triphosphate (ATP) and phosphocreatine (PCr) were examined using 31P nuclear magnetic resonance spectroscopy in the open chest state. In normal dogs, febuxostat increased PCr/ATP during basal conditions and during high workload produced by dobutamine + dopamine (P < 0.05). PCr/ATP was decreased in animals with CHF; in these animals, febuxostat (given after completing basal and high workload measurements with vehicle) tended to increase PCr/ATP during basal conditions with no effect during catecholamine stimulation. Thus, febuxostat improved LV performance in awake dogs with CHF, but caused only a trend toward increased PCr/ATP in the open chest state. It is possible that the antecedent high workload condition prior to drug administration blunted the effect of febuxostat on HEP in the CHF animals. Alternatively, beneficial effects of febuxostat on LV performance in the failing heart may not involve HEP.
McTigue, Kathleen M; Chang, Yue-Fang; Eaton, Charles; Garcia, Lorena; Johnson, Karen C; Lewis, Cora E; Liu, Simin; Mackey, Rachel H; Robinson, Jennifer; Rosal, Milagros C; Snetselaar, Linda; Valoski, Alice; Kuller, Lewis H
2014-03-01
To compare mortality, nonfatal coronary heart disease (CHD), and congestive heart failure (CHF) risk across BMI categories in white, African American, and Hispanic women, with a focus on severe obesity (BMI ≥ 40), and examine heterogeneity in weight-related CHD risk. Among 156,775 Women's Health Initiative observational study and clinical trial participants (September 1993-12 September 2005), multivariable Cox models estimated relative risk for mortality, CHD, and CHF. CHD incidence was calculated by anthropometry, race, and cardiovascular risk factors (CVRF). Mortality, nonfatal CHD, and CHF incidence generally rose with BMI category. For severe obesity versus normal BMI, hazard ratios (HRs, 95% confidence interval) for mortality were 1.97 (1.77-2.20) in white, 1.55 (1.20-2.00) in African American, and 2.59 (1.55-4.31) in Hispanic women; for CHD, HRs were 2.05 (1.80-2.35), 2.24 (1.57-3.19), and 2.95 (1.60-5.41) respectively; for CHF, HRs were 5.01 (4.33-5.80), 3.60 (2.30-5.62), and 6.05 (2.49-14.69). CVRF variation resulted in substantial variation in CHD rates across BMI categories, even in severe obesity. CHD incidence was similar by race/ethnicity when differences in BMI or CVRF were accounted for. Severe obesity increases mortality, nonfatal CHD, and CHF risk in women of diverse race/ethnicity. CVRF heterogeneity contributes to variation in CHD incidence even in severe obesity. Copyright © 2012 The Obesity Society.
Verdecchia, Paolo; Angeli, Fabio; Gattobigio, Roberto; Sardone, Mariagrazia; Porcellati, Carlo
2005-03-01
Prevalence, determinants, and prognostic value of asymptomatic left ventricular systolic dysfunction (LVSD) in uncomplicated subjects with essential hypertension are still incompletely known. We studied 2384 initially untreated subjects with hypertension, no previous cardiovascular disease, and no symptoms or physical signs of congestive heart failure (CHF). These subjects were studied at entry and followed for up to 17 years (mean 6.0). Asymptomatic LVSD (ALVSD), defined by an echocardiographic ejection fraction <50%, was found in 3.6% of subjects. Cigarette smoking (P=0.013), increased left ventricular (LV) mass (P=0.001), and higher 24-hour heart rate (P=0.014) were independent correlates of ALVSD. During follow-up, a first cardiovascular event occurred in 227 subjects, and 24 of these events were hospitalizations for symptomatic CHF. Incidence of CHF per 100 persons per year was 0.12 in patients without and 1.48 in patients with ALVSD (log-rank test P=0.0001). In a Cox model, after adjustment for age (P=0.0001), LV mass (P=0.0001), and cigarette smoking (P=0.039), LVSD conferred a markedly increased risk for CHF (odds ratio, 9.99; 95% confidence interval, 3.67 to 27.2). Incidence of coronary (0.84 versus 0.62x100 person years) and cerebrovascular (0.80 versus 0.62x100 person years) events did not differ (all P=NS) between subjects with and without ALVSD. ALVSD is a potent and early marker of evolution toward severe CHF requiring hospitalization in subjects with essential hypertension.
123I-BMIPP delayed scintigraphic imaging in patients with chronic heart failure.
Kida, Keisuke; Akashi, Yoshihiro J; Yoneyama, Kihei; Shimokawa, Mitsuhiro; Musha, Haruki
2008-11-01
The objective of the present study was to clarify the ability of 123I-beta-methyl-iodophenylpentadecanoic acid (123I-BMIPP) to evaluate the heart-to-mediastinum (H/M) ratio and myocardial global washout rate (WR) in patients with chronic heart failure (CHF). The severity of CHF was evaluated on the basis of the New York Heart Association (NYHA) classification. Twenty patients with CHF (13 with idiopathic dilated cardiomyopathy and 7 with ischemic cardiomyopathy) and 11 age-matched controls underwent myocardial radionuclide imaging. Scintigraphic images were obtained from each participant at the early (30 min following radio-isotope injection) and late (4 h) phases using 123I-BMIPP. The H/M ratio and WR were calculated from planar images. Concentrations of plasma brain natriuretic peptide (BNP) were measured prior to the scintigraphic study. The 123I-BMIPP uptake of early H/M and global WR did not significantly differ among groups, but uptake of delayed H/M was significantly lower in patients with NYHA class III than in controls (control 2.47 +/- 0.39; class III 1.78 +/- 0.28, P < 0.05). The uptake of delayed H/M and global WR correlated with plasma log BNP in all participants (r = -0.38, P < 0.05; 0.43, P < 0.05, respectively). These data suggest that 123I-BMIPP uptake of delayed H/M enhances the image of CHF severity. The myocardial WR of 123I-BMIPP also effectively depicted the severity of CHF.
Liu, Xuelu; Lou, Xueming; Cheng, Xianliang; Meng, Yong
2017-01-01
Background Metoprolol treatment is well established for chronic heart failure (CHF) patients, but the central nervous system side effects are often a potential drawback. Objective To investigate the impact of metoprolol treatment on change in mental status of CHF patients with clinical psychological disorders (such as depression, anxiety, and burnout syndrome). Methods From February 2013 to April 2016, CHF patients with clinical mental disorders received metoprolol (23.75 or 47.5 mg, qd PO, dose escalated with 23.75 mg each time until target heart rate [HR] <70 bpm was achieved) at the Second Affiliated Hospital of Kunming Medical University. Mental status was assessed by means of the Hospital Anxiety and Depression Scale (HADS) and the Copenhagen Burnout Inventory (CBI) scale. The primary outcome assessed was change in mental status of patients post-metoprolol treatment and the association with reduction in HR achieved by metoprolol. Results A total of 154 patients (median age: 66.39 years; males: n=101) were divided into eight groups on the basis of their mental status. HR decreased significantly from baseline values in all the groups to <70 bpm in the 12th month, P≤0.0001. The HADS depression and CBI scores significantly increased from baseline throughout the study frame (P≤0.0001 for all groups), but a significant decrease in the HADS anxiety score was observed in patients with anxiety (P≤0.0001 for all groups). Regression analysis revealed no significant correlation in any of the groups between the HR reduction and the change in the HADS/CBI scores, except for a change in the CBI scores of CHF patients with depression (P=0.01), which was HR dependent. Conclusion Metoprolol treatment worsens the depressive and high burnout symptoms, but affords anxiolytic benefits independent of HR reduction in CHF patients with clinical mental disorders. Hence, physicians need to be vigilant while prescribing metoprolol in CHF patients who present with mental disorders. PMID:28182127
Liu, Xuelu; Lou, Xueming; Cheng, Xianliang; Meng, Yong
2017-01-01
Metoprolol treatment is well established for chronic heart failure (CHF) patients, but the central nervous system side effects are often a potential drawback. To investigate the impact of metoprolol treatment on change in mental status of CHF patients with clinical psychological disorders (such as depression, anxiety, and burnout syndrome). From February 2013 to April 2016, CHF patients with clinical mental disorders received metoprolol (23.75 or 47.5 mg, qd PO, dose escalated with 23.75 mg each time until target heart rate [HR] <70 bpm was achieved) at the Second Affiliated Hospital of Kunming Medical University. Mental status was assessed by means of the Hospital Anxiety and Depression Scale (HADS) and the Copenhagen Burnout Inventory (CBI) scale. The primary outcome assessed was change in mental status of patients post-metoprolol treatment and the association with reduction in HR achieved by metoprolol. A total of 154 patients (median age: 66.39 years; males: n=101) were divided into eight groups on the basis of their mental status. HR decreased significantly from baseline values in all the groups to <70 bpm in the 12th month, P ≤0.0001. The HADS depression and CBI scores significantly increased from baseline throughout the study frame ( P ≤0.0001 for all groups), but a significant decrease in the HADS anxiety score was observed in patients with anxiety ( P ≤0.0001 for all groups). Regression analysis revealed no significant correlation in any of the groups between the HR reduction and the change in the HADS/CBI scores, except for a change in the CBI scores of CHF patients with depression ( P =0.01), which was HR dependent. Metoprolol treatment worsens the depressive and high burnout symptoms, but affords anxiolytic benefits independent of HR reduction in CHF patients with clinical mental disorders. Hence, physicians need to be vigilant while prescribing metoprolol in CHF patients who present with mental disorders.
Roth, D A; Urasawa, K; Helmer, G A; Hammond, H K
1993-01-01
The extent to which congestive heart failure (CHF) is dependent upon increased levels of the cardiac inhibitory GTP-binding protein (Gi), and the impact of CHF on the cardiac stimulatory GTP-binding protein (Gs) and mechanisms by which Gs may change remain unexplored. We have addressed these unsettled issues using pacing-induced CHF in pigs to examine physiological, biochemical, and molecular features of the right atrium (RA) and left ventricle (LV). CHF was associated with an 85 +/- 20% decrease in LV segment shortening (P < 0.001) and a 3.5-fold increase (P = 0.006) in the ED50 for isoproterenol-stimulated heart rate responsiveness. Myocardial beta-adrenergic receptor number was decreased 54% in RA (P = 0.004) and 57% in LV (P < 0.001), and multiple measures of adenylyl cyclase activity were depressed 49 +/- 8% in RA (P < 0.005), and 44 +/- 9% in LV (P < 0.001). Quantitative immunoblotting established that Gi and Gs were decreased in RA (Gi: 59% reduction; P < 0.0001; Gs: 28% reduction; P < 0.007) and LV (Gi: 35% reduction; P < 0.008; Gs: 28% reduction; P < 0.01) after onset of CHF. Reduced levels of Gi and Gs were confirmed by ADP ribosylation studies, and diminished function of Gs was established in reconstitution studies. Steady state levels for Gs alpha mRNA were increased in RA and unchanged in LV, and significantly more GS alpha was found in the supernatant (presumably cytosolic) fraction in RA and LV membrane homogenates after CHF, suggesting that increased Gs degradation, rather than decreased Gs synthesis, is the mechanism by which Gs is downregulated. We conclude that cardiac Gi content poorly predicts adrenergic responsiveness or contractile function, that decreased Gs is caused by increased degradation rather than decreased synthesis, and that alterations in beta-adrenergic receptors, adenylyl cyclase, and GTP-binding proteins are uniform in RA and LV in this model of congestive heart failure. Images PMID:8383705
Subclinical Hypothyroidism and Survival: The Effects of Heart Failure and Race
Curhan, Gary C.; Alexander, Erik K.; Bhan, Ishir; Brunelli, Steven M.
2013-01-01
Context: Studies examining the association between subclinical hypothyroidism and mortality have yielded conflicting results. Emerging data suggest these associations may depend upon underlying congestive heart failure (CHF) and/or race, but this has not been empirically determined. Objective: Our objective was to examine the association between subclinical hypothyroidism and hypothyroidism overall with mortality according to pre-existing CHF and race. Design and Participants: We examined the associations of subclinical hypothyroidism (TSH higher than assay upper limit of normal; total T4 within reference) and hypothyroidism overall (TSH higher than assay upper limit of normal; total T4 below lower limit of normal or within reference) with all-cause mortality among Third National Health and Nutrition Examination Survey participants stratified by CHF and race using multivariable Cox models. To confirm whether differences between strata were statistically significant, we tested for interaction on the basis of CHF (separately) and race by likelihood ratio testing. Results: There were 14 130 (95.0%) euthyroid controls and 749 (5.0%) participants with hypothyroidism, 691 (4.6%) of whom had subclinical disease. Subclinical hypothyroidism vs euthyroidism was associated with greater mortality in those with CHF but not in those without: adjusted hazard ratios (HRs) (95% confidence intervals [CIs]) = 1.44 (1.01–2.06) and 0.97 (0.85–1.11), respectively (P interaction = .03). Similar findings were observed for hypothyroidism overall. Hypothyroidism overall vs euthyroidism was associated with greater mortality in Black participants (HR = 1.44 [95% CI = 1.03–2.03]) but not in non-Blacks (HR = 0.95 [95% CI = 0.83–1.08]) (P interaction = .03). Conclusion: Among participants with CHF, subclinical hypothyroidism and hypothyroidism overall are associated with greater death risk. Additional studies are needed to confirm findings and explore possible mechanisms for the differential hypothyroidism-mortality association across race. PMID:23720788
Kubota, Yoshiaki; Asai, Kuniya; Furuse, Erito; Nakamura, Shunichi; Murai, Koji; Tsukada, Yayoi Tetsuou; Shimizu, Wataru
2015-01-01
Chronic obstructive pulmonary disease (COPD) is present in approximately one-third of all congestive heart failure (CHF) patients, and is a key cause of underprescription and underdosing of β-blockers, largely owing to concerns about precipitating respiratory deterioration. For these reasons, the aim of this study was to evaluate the impact of β-blockers on the long-term outcomes in CHF patients with COPD. In addition, we compared the effects of two different β-blockers, carvedilol and bisoprolol. The study was a retrospective, non-randomized, single center trial. Acute decompensated HF patients with COPD were classified according to the oral drug used at discharge into β-blocker (n=86; carvedilol [n=52] or bisoprolol [n=34]) and non-β-blocker groups (n=46). The primary endpoint was all-cause mortality between the β-blocker and non-β-blocker groups during a mean clinical follow-up of 33.9 months. The secondary endpoints were the differences in all-cause mortality and the hospitalization rates for CHF and/or COPD exacerbation between patients receiving carvedilol and bisoprolol. The mortality rate was higher in patients without β-blockers compared with those taking β-blockers (log-rank P=0.039), and univariate analyses revealed that the use of β-blockers was the only factor significantly correlated with the mortality rate (hazard ratio: 0.41; 95% confidence interval: 0.17-0.99; P=0.047). Moreover, the rate of CHF and/or COPD exacerbation was higher in patients treated with carvedilol compared with bisoprolol (log-rank P=0.033). In the multivariate analysis, only a past history of COPD exacerbation significantly increased the risk of re-hospitalization due to CHF and/or COPD exacerbation (adjusted hazard ratio: 3.11; 95% confidence interval: 1.47-6.61; P=0.003). These findings support the recommendations to use β-blockers in HF patients with COPD. Importantly, bisoprolol reduced the incidence of CHF and/or COPD exacerbation compared with carvedilol.
Brain natriuretic peptide in patients with congestive heart failure and central sleep apnea.
Carmona-Bernal, Carmen; Quintana-Gallego, Esther; Villa-Gil, Manuel; Sánchez-Armengol, Angeles; Martínez-Martínez, Angel; Capote, Francisco
2005-05-01
To assess the possible relationship between Cheyne-Stokes respiration (CSR) associated with central sleep apnea (CSA) syndrome and brain natriuretic peptide (BNP) in an outpatient population presenting with stable congestive heart failure (CHF). Ninety patients with CHF due to systolic dysfunction (left ventricular ejection fraction
Geib, Tanja; Plappert, Nina; Roth, Tatjana; Popp, Roland; Birner, Christoph; Maier, Lars S; Pfeifer, Michael; Arzt, Michael
2015-07-01
Sleep-disordered breathing (SDB) is highly prevalent in patients with chronic heart failure (CHF) and is associated with a poor prognosis. Data on SDB-related symptoms and vigilance impairment in patients with CHF and SDB are rare. Thus, the objective of the present study was to assess a wide spectrum of SDB-related symptoms and objective vigilance testing in patients with CHF with and without SDB. Patients with CHF (n = 222; average age, 62 years; left ventricular ejection fraction [LVEF], 34%) underwent polysomnography regardless of the presence or absence of SDB-related symptoms. Patients were stratified into those with no SDB (apnea-hypopnea index [AHI] < 15 episodes/h), moderate SDB (AHI ≥ 15 to < 30 episodes/h), and severe SDB (AHI ≥ 30 episodes/h). A standardized institutional questionnaire assessing a wide spectrum of SDB-related symptoms was applied. A subset of patients underwent objective vigilance testing (Quatember Maly, 100 stimuli within 25 minutes). Daytime fatigue (no SDB, moderate SDB, and severe SDB: 53%, 69%, and 80%, respectively; P = 0.005), unintentional sleep (9%, 15%, and 32%, respectively; P = 0.004), and xerostomia (52%, 49%, and 70%, respectively; P = 0.018), as well as an impaired objective vigilance test result (mean reaction time, 0.516, 0.497, and 0.579 ms, respectively; P < 0.001) occurred more frequently with increasing severity of SDB. Seventy-eight percent of patients with CHF and SDB had at least 3 SDB-related symptoms. In a linear multivariable regression model, the frequency of daytime fatigue (P = 0.014), unintentional sleep (P = 0.001), xerostomia (P = 0.016), and mean reaction time (P = 0.001) were independently associated with increasing AHI independent of age, body mass index, New York Heart Association functional class, and LVEF. The majority of patients with CHF and SDB have several potential SDB-related symptoms and objective impairment of vigilance as potential treatment targets. Copyright © 2015 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.
Modrall, J Gregory; Rosero, Eric B; Timaran, Carlos H; Anthony, Thomas; Chung, Jayer; Valentine, R James; Trimmer, Clayton
2012-02-01
The goal of the study was to determine the blood pressure (BP) response to renal artery stenting (RAS) for patients with hypertension urgency, hypertension emergency, and angina with congestive heart failure (angina/congestive heart failure [CHF]). Patients who underwent RAS for hypertension emergencies (n = 13), hypertension urgencies (n = 25), and angina/CHF (n = 14) were included in the analysis. By convention, hypertension urgency was defined by a sustained systolic BP ≥ 180 mm Hg or diastolic BP ≥ 120 mm Hg, while the definition of hypertension emergency required the same BP parameters plus hypertension-related symptoms prompting hospitalization. Patient-specific response to RAS was defined according to modified American Heart Association reporting guidelines. The study cohort of 52 patients had a median age of 66 years (interquartile range 58-72). The BP response to RAS varied significantly according to the indication for RAS. Hypertension emergency provided the highest BP response rate (85%), while the response rate was significantly lower for hypertension urgency (52%) and angina/CHF (7%; P = .03). Only 1 of 14 patients with angina/CHF was a BP responder. Multivariate analysis showed that hypertension urgency or emergency were not independent predictors of BP response to RAS. Instead, the only independent predictor of a favorable BP response was the number of preoperative antihypertensive medications (odds ratio 7.5; 95% confidence interval 2.5-22.9; P = .0004), which is another indicator of the severity of hypertension. Angina/CHF was an independent predictor of failure to respond to RAS (odds ratio 118.6; 95% confidence interval 2.8-999.9; P = .013). Hypertension urgency and emergency are clinical manifestations of severe hypertension, but the number of preoperative antihypertensive medications proved to be a better predictor of a favorable BP response to RAS. In contrast, angina/CHF was a predictor of failure to respond to stenting, providing further evidence against the practice of incidental stenting during coronary interventions. Copyright © 2012 Society for Vascular Surgery. All rights reserved.
2013-01-01
Background The National Health Insurance Fund (NHIF), a compulsory formal sector scheme took over the management of the Community Health Fund (CHF), a voluntary informal sector scheme, in 2009. This study assesses the origins of the reform, its effect on management and reporting structures, financial flow adequacy, reform communication and acceptability to key stakeholders, and initial progress towards universal coverage. Methods The study relied on national data sources and an in-depth collective case study of a rural and an urban district to assess awareness and acceptability of the reform, and fund availability and use relative to need in a sample of facilities. Results The reform was driven by a national desire to expand coverage and increase access to services. Despite initial delays, the CHF has been embedded within the NHIF organisational structure, bringing more intensive and qualified supervision closer to the district. National CHF membership has more than doubled. However, awareness of the reform was limited below the district level due to the reform’s top-down nature. The reform was generally acceptable to key stakeholders, who expected that benefits between schemes would be harmonised. The reform was unable to institute changes to the CHF design or district management structures because it has so far been unable to change CHF legislation which also limits facility capacity to use CHF revenue. Further, revenue generated is currently insufficient to offset treatment and administration costs, and the reform did not improve the revenue to cost ratio. Administrative costs are also likely to have increased as a result of the reform. Conclusion Informal sector schemes can benefit from merger with formal sector schemes through improved data systems, supervision, and management support. However, effects will be maximised if legal frameworks can be harmonised early on and a reduction in administrative costs is not guaranteed. PMID:23763711
Fröhlich, Hanna; Nelges, Christoph; Täger, Tobias; Schwenger, Vedat; Cebola, Rita; Schnorbach, Johannes; Goode, Kevin M; Kazmi, Syed; Katus, Hugo A; Cleland, John G F; Clark, Andrew L; Frankenstein, Lutz
2016-08-01
Angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) have become cornerstones of therapy for chronic heart failure (CHF). Guidelines advise high target doses for ACEIs/ARBs, but fear of worsening renal function may limit dose titration in patients with concomitant chronic kidney disease (CKD). In this retrospective observational study, we identified 722 consecutive patients with systolic CHF, stable CKD stage III/IV (estimated glomerular filtration rate [eGFR] 15-60 mL min(-1) 1.73 m(-2)) and chronic ACEI/ARB treatment from the outpatient heart failure clinics at the Universities of Hull, UK, and Heidelberg, Germany. Change of renal function, worsening CHF, and hyperkalemia at 12-month follow-up were analyzed as a function of both baseline ACEI/ARB dose and dose change from baseline. ΔeGFR was not related to baseline dose of ACEI/ARB (P = .58), or to relative (P = .18) or absolute change of ACEI/ARB dose (P = .21) during follow-up. Expressing change of renal function as a categorical variable (improved/stable/decreased) as well as subgroup analyses with respect to age, sex, New York Heart Association functional class, left ventricular ejection fraction, diabetes, concomitant aldosterone antagonists, CKD stage, hypertension, ACEI vs ARB, and congestion status yielded similar results. There was no association of dose/dose change with incidence of either worsening CHF or hyperkalemia. In patients with systolic CHF and stable CKD stage III/IV, neither continuation of high doses of ACEI/ARB nor up-titration was related to adverse changes in longer-term renal function. Conversely, down-titration was not associated with improvement in eGFR. Use of high doses of ACEI/ARB and their up-titration in patients with CHF and CKD III/IV may be appropriate provided that the patient is adequately monitored. Copyright © 2016 Elsevier Inc. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gillis, K.A.
1997-01-01
Measurements of the speed of sound in seven halogenated hydrocarbons are presented. The compounds in this study are 1-chloro-,2,2,2-tetrafluoroethane (CHCIFCF{sub 3} or HCFC-124), pentafluoroethane (CHF{sub 2}CF{sub 3} or HFC-125), 1,1,1-trifluoroethane (CF{sub 3}CH{sub 3} or HFC-143a), 1,1-difluoroethane (CHF{sub 2}CH{sub 3} or HFC-152a), 1,1,2,3,3-hexafluoropropane (CF{sub 3}CHFCHF{sub 2} or HFC-236ea), 1,1,1,3,3,3-hexafluoropropane (CF{sub 3}CH{sub 2}CF{sub 3} or HFC-236fa), and 1,1,2,2,3-pentafluoropropane (CHF{sub 2}CF{sub 2}CH{sub 2}F or HFC-245ca). The measurements were performed with a cylindrical resonator at temperatures between 240 and 400 K and at pressures up to 1.0 MPa. Ideal-gas heat capacities and acoustic virial coefficients were directly deduced from the data. The ideal-gas heatmore » capacity of HFC-125 from this work differs from spectroscopic calculations by less than 0.2% over the measurement range. The coefficients for virial equations of state were obtained from the acoustic data and hard-core square-well intermolecular potentials. Gas densities that were calculated from the virial equations of state for HCFC-124 and HFC-125 differ from independent density measurements by at most 0.15%, for the ranges of temperature and pressure over which both acoustic and Burnett data exist. The uncertainties in the derived properties of the other five compounds are comparable to those for HCFC-124 and HFC-125.« less
An experiment with community health funds in Afghanistan.
Rao, Krishna D; Waters, Hugh; Steinhardt, Laura; Alam, Sahibullah; Hansen, Peter; Naeem, Ahmad Jan
2009-07-01
As Afghanistan rebuilds its health system, it faces key challenges in financing health services. To reduce dependence on donor funds, it is important to develop sustainable local financing mechanisms. A second challenge is to reduce high levels of out-of-pocket payments. Community-based health insurance (CBHI) schemes offer the possibility of raising revenues from communities and at the same time providing financial protection. This paper describes the performance of one type of CBHI scheme, the Community Health Fund (CHF), which was piloted for the first time in five provinces of Afghanistan between June 2005 and October 2006. The performance of the CHF programme demonstrates that complex community-based health financing schemes can be implemented in post-conflict settings like Afghanistan, except in areas of high insecurity. The funds raised from the community, via premiums and user fees, enabled the pilot facilities to overcome temporary shortages of drugs and supplies, and to conduct outreach services via mobile clinics. However, enrolment and cost-recovery were modest. The median enrolment rate for premium-paying households was 6% of eligible households in the catchment areas of the clinics. Cost recovery rates ranged up to 16% of total operating costs and 32% of non-salary operating costs. No evidence of reduced out-of-pocket health expenditures was observed at the community level, though CHF members had markedly higher utilization of health services. The main reasons among non-members for not enrolling were being unaware of the programme; high premiums; and perceived low quality of services at the CHF clinics. The performance of Afghanistan's CHF was similar to other CHF-type programmes operating at the primary care level internationally. The solution to building local capacity to finance health services lies in a combination of financing sources rather than any single mechanism. In this context, it is critical that international assistance for Afghanistan's health sector continues.
NASA Technical Reports Server (NTRS)
Hsu, K.-J.; DeMore, W. B.
1995-01-01
Rate constants of 15 OH reactions with halogen-substituted alkanes, C1 to C3, were studied using a relative rate technique in the temperature range 283-403 K. Compounds studied were CHF2Cl (22), CHF2Br (22B), CH3F (41), CH2F2 (32), CHF3 (23), CHClFCCl2F (122a), CHCl2CF3 (123), CHClFCF3 (124), CH3CF3 (143a), CH3CH2F (161), CF3CHFCF3 (227ea), CF3CH2CF3 (236fa), CF3CHFCHF2 (236ea), and CHF2CF2CH2F (245ca). Using CH4, CH3CCl3, CF3CF2H, and C2H6 as primary reference standards (JPL 92-20 rate constants), absolute rate constants are derived. Results are in good agreement with previous experimental results for six of the compounds studied, including CHF2Cl, CHF2Br, CH2F2, CH3CF3, CHFClCFCl2, and CF3CHFCF3. For the remainder the relative rate constants are lower than those derived from experiments in which OH loss was used to measure the reaction rate. Comparisons of the derived Arrhenius A factors with previous literature transition-state calculations show order of magnitude agreement in most cases. However, the experimental A factors show a much closer proportionality to the number of H atoms in the molecule than is evident from the transition state calculations. For most of the compounds studied, an A factor of (8 +/- 3)E-13 cm(exp 3)/(molecule s) per C-H bond is observed. A new measurement of the ratio k(CH3CCl3)/k(CH4) is reported that is in good agreement with previous data.
2012-01-01
Background Adults with certain comorbid conditions have a higher risk of pneumonia than the overall population. If treatment of pneumonia is more costly in certain predictable situations, this would affect the value proposition of populations for pneumonia prevention. We estimate the economic impact of community-acquired pneumonia (CAP) for adults with asthma, diabetes, chronic obstructive pulmonary disease (COPD) and congestive heart failure (CHF) in a large U.S. commercially-insured working age population. Methods Data sources consisted of 2003 through 2007 Thomson Reuters MarketScan Commercial Claims and Encounters and Thomson Reuters Health Productivity and Management (HPM) databases. Pneumonia episodes and selected comorbidities were identified by ICD-9-CM diagnosis codes. By propensity score matching, controls were identified for pneumonia patients. Excess direct medical costs and excess productivity cost were estimated by generalized linear models (GLM). Results We identified 402,831 patients with CAP between 2003 through 2007, with 25,560, 32,677, 16,343, and 5,062 episodes occurring in patients with asthma, diabetes, COPD and CHF, respectively. Mean excess costs (and standard error, SE) of CAP were $14,429 (SE=44) overall. Mean excess costs by comorbidity subgroup were lowest for asthma ($13,307 (SE=123)), followed by diabetes ($21,395 (SE=171)) and COPD ($23,493 (SE=197)); mean excess costs were highest for patients with CHF ($34,436 (SE=549)). On average, indirect costs comprised 21% of total excess costs, ranging from 8% for CHF patients to 27% for COPD patients. Conclusions Compared to patients without asthma, diabetes, COPD, or CHF, the excess cost of CAP is nearly twice as high for patients with diabetes and COPD and nearly three times as high for patients with CHF. Indirect costs made up a significant but varying portion of excess CAP costs. Returns on prevention of pneumonia would therefore be higher in adults with these comorbidities. PMID:23113880
Polsky, Daniel; Bonafede, Machaon; Suaya, Jose A
2012-10-31
Adults with certain comorbid conditions have a higher risk of pneumonia than the overall population. If treatment of pneumonia is more costly in certain predictable situations, this would affect the value proposition of populations for pneumonia prevention. We estimate the economic impact of community-acquired pneumonia (CAP) for adults with asthma, diabetes, chronic obstructive pulmonary disease (COPD) and congestive heart failure (CHF) in a large U.S. commercially-insured working age population. Data sources consisted of 2003 through 2007 Thomson Reuters MarketScan Commercial Claims and Encounters and Thomson Reuters Health Productivity and Management (HPM) databases. Pneumonia episodes and selected comorbidities were identified by ICD-9-CM diagnosis codes. By propensity score matching, controls were identified for pneumonia patients. Excess direct medical costs and excess productivity cost were estimated by generalized linear models (GLM). We identified 402,831 patients with CAP between 2003 through 2007, with 25,560, 32,677, 16,343, and 5,062 episodes occurring in patients with asthma, diabetes, COPD and CHF, respectively. Mean excess costs (and standard error, SE) of CAP were $14,429 (SE=44) overall. Mean excess costs by comorbidity subgroup were lowest for asthma ($13,307 (SE=123)), followed by diabetes ($21,395 (SE=171)) and COPD ($23,493 (SE=197)); mean excess costs were highest for patients with CHF ($34,436 (SE=549)). On average, indirect costs comprised 21% of total excess costs, ranging from 8% for CHF patients to 27% for COPD patients. Compared to patients without asthma, diabetes, COPD, or CHF, the excess cost of CAP is nearly twice as high for patients with diabetes and COPD and nearly three times as high for patients with CHF. Indirect costs made up a significant but varying portion of excess CAP costs. Returns on prevention of pneumonia would therefore be higher in adults with these comorbidities.
Ayaz, Muhammad; Junaid, Muhammad; Ullah, Farhat; Sadiq, Abdul; Subhan, Fazal; Khan, Mir Azam; Ahmad, Waqar; Ali, Gowhar; Imran, Muhammad; Ahmad, Sajjad
2016-01-01
Polygonum hydropiper is used as anti-cancer and anti-rheumatic agent in folk medicine. This study was designed to investigate the anti-angiogenic, anti-tumor, and cytotoxic potentials of different solvent extracts and isolated saponins. Samples were analyzed using GC, Gas Chromatography–Mass Spectrometry (GC–MS) to identify major and bioactive compounds. Quantitation of antiangiogenesis for the plant's samples including methanolic extract (Ph.Cr), its subsequent fractions; n-hexane (Ph.Hex), chloroform (Ph.Chf), ethyl acetate (Ph.EtAc), n-Butanol (Ph.Bt), aqueous (Ph.Aq), saponins (Ph.Sp) were performed using the chick embryo chorioallantoic membrane (CAM) assay. Potato disc anti-tumor assay was performed on Agrobacterium tumefaciens containing tumor inducing plasmid. Cytotoxicity was performed against Artemia salina and mouse embryonic fibroblast NIH/3T3 cell line following contact toxicity and MTT cells viability assays, respectively. The GC–MS analysis of Ph.Cr, Ph.Hex, Ph.Chf, Ph.Bt, and Ph.EtAc identified 126, 124, 153, 131, and 164 compounds, respectively. In anti-angiogenic assay, Ph.Chf, Ph.Sp, Ph.EtAc, and Ph.Cr exhibited highest activity with IC50 of 28.65, 19.21, 88.75, and 461.53 μg/ml, respectively. In anti-tumor assay, Ph.Sp, Ph.Chf, Ph.EtAc, and Ph.Cr were most potent with IC50 of 18.39, 73.81, 217.19, and 342.53 μg/ml, respectively. In MTT cells viability assay, Ph.Chf, Ph.EtAc, Ph.Sp were most active causing 79.00, 72.50, and 71.50% cytotoxicity, respectively, at 1000 μg/ml with the LD50 of 140, 160, and 175 μg/ml, respectively. In overall study, Ph.Chf and Ph.Sp have shown overwhelming results which signifies their potentials as sources of therapeutic agents against cancer. PMID:27065865
Chamberlain, Ronald S; Sond, Jaswinder; Mahendraraj, Krishnaraj; Lau, Christine SM; Siracuse, Brianna L
2018-01-01
Background Chronic heart failure (CHF), which affects >5 million Americans, accounts for >1 million hospitalizations annually. As a part of the Hospital Readmission Reduction Program, the Affordable Care Act requires that the Centers for Medicare and Medicaid Services reduce payments to hospitals with excess readmissions. This study sought to develop a scale that reliably predicts readmission rates among patients with CHF. Methods The State Inpatient Database (2006–2011) was utilized, and discharge data including demographic and clinical characteristics on 642,448 patients with CHF from California and New York (derivation cohort) and 365,359 patients with CHF from Florida and Washington (validation cohort) were extracted. The Readmission After Heart Failure (RAHF) scale was developed to predict readmission risk. Results The 30-day readmission rates were 9.42 and 9.17% (derivation and validation cohorts, respectively). Age <65 years, male gender, first income quartile, African American race, race other than African American or Caucasian, Medicare, Medicaid, self-pay/no insurance, drug abuse, renal failure, chronic pulmonary disorder, diabetes, depression, and fluid and electrolyte disorder were associated with higher readmission risk after hospitalization for CHF. The RAHF scale was created and explained the 95% of readmission variability within the validation cohort. The RAHF scale was then used to define the following three levels of risk for readmission: low (RAHF score <12; 7.58% readmission rate), moderate (RAHF score 12–15; 9.78% readmission rate), and high (RAHF score >15; 12.04% readmission rate). The relative risk of readmission was 1.67 for the high-risk group compared with the low-risk group. Conclusion The RAHF scale reliably predicts a patient’s 30-day CHF readmission risk based on demographic and clinical factors present upon initial admission. By risk-stratifying patients, using models such as the RAHF scale, strategies tailored to each patient can be implemented to improve patient outcomes and reduce health care costs. PMID:29670391
Kocaman, Sinan Altan; Taçoy, Gülten; Ozdemir, Murat; Açıkgöz, Sadık Kadri; Cengel, Atiye
2010-12-01
Autonomic dysfunction is an important marker of prognosis in congestive heart failure (CHF) and may determine the symptoms and progression of CHF. The aim of our study was to investigate whether preserved autonomic function assessed by heart rate variability (HRV) analyses is related to absence of CHF symptoms despite prominently reduced systolic function. The study had a cross-sectional observational design. Fifty patients with left ventricular ejection fraction (EF) below 40% were enrolled. The patients were divided into two groups according to their CHF symptomatic status as Group 1 (NYHA functional class I, asymptomatic group) and Group 2 (NYHA functional class ≥ II, symptomatic group). Plasma C-reactive protein (CRP), N-terminal proB-type natriuretic peptide (NT-proBNP) levels, echocardiographic parameters and HRV indices were measured while the patients were clinically stable in each group. Possible factors associated with the development of CHF symptoms were assessed by using multiple regression analysis. Baseline clinical characteristics and left ventricular EF were similar in the two groups. Serum CRP (15 ± 21 vs 7 ± 18 mg/L, p=0.011) and NT-proBNP levels (1935 ± 1088 vs 1249 ± 1083 pg/mL, p=0.020) were significantly higher in symptomatic group. The HRV parameters (SDNN: 78 ± 57 vs 122 ± 42 ms, p=0.001; SDANN: 65 ± 55 vs 84 ± 38 ms, p=0.024; SDNNi: 36 ± 41 vs 70 ± 46 ms, p<0.001; triangular index [Ti]: 17 ± 12 vs 32 ± 14, p<0.001) were also significantly depressed in symptomatic group. When multiple regression analysis was performed, only HRV indices of autonomic function were significantly associated with the asymptomatic status (SDNN, OR: 1.016, 95%CI: 1.002-1.031, p=0.028; SDNNi, OR: 1.030, 95%CI: 1.008-1.052, p=0.006; TI, OR: 1.088, 95%CI: 1.019-1.161, p=0.011). Preserved autonomic functions were shown to be associated with absence of CHF symptoms independently of angiotensin converting enzyme inhibitor/angiotensin receptor blocker's treatment and BNP levels and may be protective against the development of CHF symptoms despite advanced left ventricular systolic dysfunction.
An agent-based simulation model to study accountable care organizations.
Liu, Pai; Wu, Shinyi
2016-03-01
Creating accountable care organizations (ACOs) has been widely discussed as a strategy to control rapidly rising healthcare costs and improve quality of care; however, building an effective ACO is a complex process involving multiple stakeholders (payers, providers, patients) with their own interests. Also, implementation of an ACO is costly in terms of time and money. Immature design could cause safety hazards. Therefore, there is a need for analytical model-based decision-support tools that can predict the outcomes of different strategies to facilitate ACO design and implementation. In this study, an agent-based simulation model was developed to study ACOs that considers payers, healthcare providers, and patients as agents under the shared saving payment model of care for congestive heart failure (CHF), one of the most expensive causes of sometimes preventable hospitalizations. The agent-based simulation model has identified the critical determinants for the payment model design that can motivate provider behavior changes to achieve maximum financial and quality outcomes of an ACO. The results show nonlinear provider behavior change patterns corresponding to changes in payment model designs. The outcomes vary by providers with different quality or financial priorities, and are most sensitive to the cost-effectiveness of CHF interventions that an ACO implements. This study demonstrates an increasingly important method to construct a healthcare system analytics model that can help inform health policy and healthcare management decisions. The study also points out that the likely success of an ACO is interdependent with payment model design, provider characteristics, and cost and effectiveness of healthcare interventions.
Post-Acute Home Care and Hospital Readmission of Elderly Patients with Congestive Heart Failure
ERIC Educational Resources Information Center
Li, Hong; Morrow-Howell, Nancy; Proctor, Enola K.
2004-01-01
After inpatient hospitalization, many elderly patients with congestive heart failure (CHF) are discharged home and receive post-acute home care from informal (family) caregivers and formal service providers. Hospital readmission rates are high among elderly patients with CHF, and it is thought that use of informal and formal services may reduce…
DOE Office of Scientific and Technical Information (OSTI.GOV)
Cai, Yunhai
Similar to a super B-factory, a circular Higgs factory (CHF) will require strong focusing systems near the interaction points and a low-emittance lattice in the arcs to achieve a factory luminosity. At electron beam energy of 125 GeV, beamstrahlung effects during the collision pose an additional challenge to the collider design. In particular, a large momentum acceptance at the 2% level is necessary to retain an adequate beam lifetime. This turns out to be the most challenging aspect in the design of a CHF. In this paper, an example will be provided to illustrate the beam dynamics in a CHF,more » emphasizing the chromatic optics. Basic optical modules and advanced analysis will be presented. Most importantly, we will show that 2% momentum aperture is achievable.« less
Current status of stem cells in cardiac repair.
Henning, Robert J
2018-03-01
One out of every two men and one out of every three women greater than the age of 40 will experience an acute myocardial infarction (AMI) at some time during their lifetime. As more patients survive their AMIs, the incidence of congestive heart failure (CHF) is increasing. 6 million people in the USA have ischemic cardiomyopathies and CHF. The search for new and innovative treatments for patients with AMI and CHF has led to investigations and use of human embryonic stem cells, cardiac stem/progenitor cells, bone marrow-derived mononuclear cells and mesenchymal stem cells for treatment of these heart conditions. This paper reviews current investigations with human embryonic, cardiac, bone marrow and mesenchymal stem cells, and also stem cell paracrine factors and exosomes.
Near azeotropic mixture substitute
NASA Technical Reports Server (NTRS)
Jones, Jack A. (Inventor)
1996-01-01
The present invention comprises a refrigerant mixture consisting of a first mole fraction of 1,1,1,2-tetrafluoroethane (R134a) and a second mole fraction of a component selected from the group consisting of a mixture of CHClFCF.sub.3 (R124) and CH.sub.3 CClF.sub.2 (R142b); a mixture of CHF.sub.2 CH.sub.3 (R152a) and CHClFCF.sub.3 (R124); a mixture of CHF.sub.2 CH.sub.3 (R152a) and CH.sub.3 CClF.sub.2 (R142b); and a mixture of CHClFCF.sub.3 (R124), CH.sub.3 CClF.sub.2 (R142b) and CHF.sub.2 CH.sub.3 (R152a).
Kemper, Kathi J; Carmin, Cheryl; Mehta, Bella; Binkley, Phillip
2016-10-01
Congestive heart failure (CHF) has a high rate of morbidity and mortality. It is often accompanied by other medical and psychosocial comorbidities that complicate treatment and adherence. We conducted a proof of concept pilot project to determine the feasibility of providing integrative group medical visits plus mindfulness training for patients recently discharged with CHF. Patients were eligible if they had been discharged from an inpatient stay for CHF within the 12 months prior to the new program. The Compassionate Approach to Lifestyle and Mind-Body (CALM) Skills for Patients with CHF consisted of 8 weekly visits focusing on patient education about medications, diet, exercise, sleep, and stress management; group support; and training in mind-body skills such as mindfulness, self-compassion, and loving-kindness. Over two 8-week sessions, 8/11 (73%) patients completed at least 4 visits. The patients had an average age of 57 years. The most common comorbidities were weight gain, sleep problems, and fatigue. After the sessions, 100% of patients planned to make changes to their diet, exercise, and stress management practices. Over half of the patients who met with a pharmacist had a medication-related problem. Improvements were observed in depression, fatigue, and satisfaction with life. Integrative group visits focusing on healthy lifestyle, support, and skill-building are feasible even among CHF patients and should be evaluated in controlled trials as a patient-centered approach to improving outcomes related to improving medication management, depression, fatigue, and quality of life. © The Author(s) 2015.
Otsu, Haruka; Moriyama, Michiko
2012-12-01
There are few studies dealing with comprehensive chronic heart failure (CHF) disease management programs, which are based on self-management, in Japan. We developed and conducted a comprehensive educational program for CHF for 6 months that aimed to improve self-management and prevent the deterioration of outpatients with CHF. Our follow-up research focused on whether performance of self-management in the intervention group continued for 24 months after commencement. Participants were selected from patients who went for follow-up visits to one Japanese clinic, which specialized in cardiovascular internal medicine, that were diagnosed with CHF. During the first follow-up period, 7 to 12 months after program commencement, 47 participants in the intervention group and 47 participants in the control group were analyzed. During the second follow-up period, 13 to 24 months after program commencement, 41 participants in the intervention group were analyzed. Participants in the intervention group acquired self-management skills and activities and these continued up to 24 months after the program commencement. As a result, no deterioration in symptoms related to CHF was demonstrated. Meanwhile, quitting smoking and drinking depended on individual preference and it was difficult to improve. The educational program was effective in the long term and the program is significant for use in busy medical situations that do not offer sufficient follow-up support for patients. Regular intervention and ways that produce longer-lasting effects should be further developed. © 2011 The Authors. Japan Journal of Nursing Science © 2011 Japan Academy of Nursing Science.
Ekedahl, Anders; Brosius, Helen; Jönsson, Julia; Karlsson, Hanna; Yngvesson, Maria
2011-11-01
To study discrepancies between (i) the prescribed current treatment stated by patients with congestive heart failure (CHF) compared with patients with other chronic diseases, (ii) the data in the medication list (ML) in the electronic medical record and (iii) the data in the prescription list (PL) on the prescriptions stored in the national prescription repository in Sweden, to determine current, noncurrent, duplicate and missing prescriptions. At one healthcare centre, a random sample of patients 18 years and older with a diagnosis of CHF, diabetes mellitus (DM) or osteoarthritis (OA) provided written informed consent to participate. Participants were interviewed by telephone on the prescribed current treatment. Of 161 invited patients (61 CHF, 50 DM and 50 OA), 66 patients were included. More than 80% of the patients had at least one discrepancy, a noncurrent, a duplicate or a missing prescription, in the ML and PL. The overall congruence for unique prescriptions on current treatment between the ML and the PL was only 55%. Patients with CHF had overall more discrepancies and patients with DM fewer discrepancies in the ML. Prescriptions for noncurrent treatment, duplicates and missing prescriptions are common in both the ML in the electronic medical record and the list on prescriptions stored in the Swedish National Prescription Repository. Patients with CHF had more discrepancies in the ML. The risk for medication errors in primary care due to incorrect information on prescribed treatment may be substantial. Copyright © 2011 John Wiley & Sons, Ltd.
Torre-Amione, Guillermo; Sestier, François; Radovancevic, Branislav; Young, James
2005-06-06
Immune activation and inflammation contribute to the progression of chronic heart failure (CHF), but therapeutic approaches directed against these processes have been largely unsuccessful. This clinical study evaluated a novel, nonpharmacologic immune modulation therapy, shown experimentally to reduce inflammatory and increase anti-inflammatory cytokines. A total of 75 patients with New York Heart Association (NYHA) functional class III or IV CHF were randomized to receive either Celacade (immune modulation therapy) or placebo (n = 38 and n = 37, respectively) in a double-blind trial for 6 months, during which standard therapy for CHF was maintained. Patients were evaluated using the 6-minute walk test, changes in NYHA class, cardiac function, and quality-of-life assessments, and were observed for the occurrence of death and hospitalization. There was no between-treatment difference in the 6-minute walk test results, but 15 Celacade-treated patients (compared with 9 placebo-treated patients) improved NYHA classification by > or = 1 class (p = 0.140). Kaplan-Meier survival analysis showed that Celacade significantly reduced the risk of death (p = 0.022) and hospitalization (p = 0.008). Analysis of a clinical composite score demonstrated a significant between-group difference (p = 0.006). There was no difference in left ventricular ejection fraction between groups, but there was a trend toward improved quality of life favoring the Celacade-treated group (p = 0.110). These preliminary findings are consistent with the hypothesis that immune activation is important in the pathogenesis of CHF, and they establish the basis for a phase 3 trial to define the benefit of Celacade in CHF.
Matter-Walstra, K; Ruhstaller, T; Klingbiel, D; Schwenkglenks, M; Dedes, K J
2016-07-01
Endocrine therapy continues to be the optimal systemic treatment for metastatic ER(+)HER2(-) breast cancer. The CDK4/6 inhibitor palbociclib combined with letrozole has recently been shown to significantly improve progression-free survival. Here we examined the cost-effectiveness of this regimen for the Swiss healthcare system. A Markov cohort simulation based on the PALOMA-1 trial (Finn et al. in Lancet Oncol 16:25-35, 2015) was used as the clinical course. Input parameters were based on summary trial data. Costs were assessed from the Swiss healthcare system perspective. Adding palbociclib to letrozole (PALLET) compared to letrozole monotherapy was estimated to cost an additional CHF342,440 and gain 1.14 quality-adjusted life years, resulting in an incremental cost-effectiveness ratio (ICER) of CHF301,227/QALY gained. In univariate sensitivity analyses, no tested variation in key parameters resulted in an ICER below a willingness-to-pay threshold of CHF100,000/QALY. PALLET had a 0 % probability of being cost-effective in probabilistic sensitivity analyses. Lowering PALLET's price by 75 % resulted in an ICER of CHF73,995/QALY and a 73 % probability of being cost-effective. At current prices, PALLET would cost the Swiss healthcare system an additional CHF155 million/year. Palbociclib plus letrozole cannot be considered cost-effective for the first-line treatment of patients with metastatic breast cancer in the Swiss healthcare system.
NASA Astrophysics Data System (ADS)
Lin, Yu-Cheng; Lin, Yu-Hsuan; Lo, Men-Tzung; Peng, Chung-Kang; Huang, Norden E.; Yang, Cheryl C. H.; Kuo, Terry B. J.
2016-02-01
The complex fluctuations in heart rate variability (HRV) reflect cardiac autonomic modulation and are an indicator of congestive heart failure (CHF). This paper proposes a novel nonlinear approach to HRV investigation, the multi dynamic trend analysis (MDTA) method, based on the empirical mode decomposition algorithm of the Hilbert-Huang transform combined with a variable-sized sliding-window method. Electrocardiographic signal data obtained from the PhysioNet database were used. These data were from subjects with CHF (mean age = 59.4 ± 8.4), an age-matched elderly healthy control group (59.3 ± 10.6), and a healthy young group (30.3 ± 4.8); the HRVs of these subjects were processed using the MDTA method, time domain analysis, and frequency domain analysis. Among all HRV parameters, the MDTA absolute value slope (MDTS) and MDTA deviation (MDTD) exhibited the greatest area under the curve (AUC) of the receiver operating characteristics in distinguishing between the CHF group and the healthy controls (AUC = 1.000) and between the healthy elderly subject group and the young subject group (AUC = 0.834 ± 0.067 for MDTS; 0.837 ± 0.066 for MDTD). The CHF subjects presented with lower MDTA indices than those of the healthy elderly subject group. Furthermore, the healthy elderly subjects exhibited lower MDTA indices than those of the young controls. The MDTA method can adaptively and automatically identify the intrinsic fluctuation on variable temporal and spatial scales when investigating complex fluctuations in the cardiac autonomic regulation effects of aging and CHF.
Yoga for heart failure patients: a feasibility pilot study with a multiethnic population.
Kubo, Ai; Hung, Yun-Yi; Ritterman, Jeffrey
2011-01-01
Congestive heart failure (CHF) is highly prevalent and the most costly cardiovascular illness in the United States. Yoga is known to be effective in lowering stress, lessening depression, and increasing physical fitness and may be used as an adjuvant management program for CHF patients. To determine the feasibility of a yoga intervention program among a multiethnic CHF population living in underserved neighborhoods. Uncontrolled intervention trial. Kaiser Permanente Medical Centers, Richmond and Oakland, California. 14 CHF patients (7 female), mean age 64 (SD=6.4) years, and 62% African-American. Eight-week, 2x/week, 1-hr yoga classes that included meditation, breathing exercises, gentle yoga poses, and relaxation. The intervention feasibility was measured by recruitment rates, participant retention and adherence. Body weight and self-reported depression and quality of life were measured before and after the intervention. Among the 14 patients enrolled, 13 completed the intervention. Of those who completed the trial, 92% attended at least 50% of the classes. There was a significant reduction in weight (-3.5 lb, p=0.01) and improvement in the severity of depression (p<0.05), as well as a trend toward increased quality of life (p=08). No adverse events were observed. This pilot trial demonstrates that it is feasible for patients with CHF to incorporate yoga into their lifestyle. Yoga may help with routine disease management, prevention of fluid retention, and improvement of depression and quality of life. A larger trial is needed to confirm efficacy and to determine the long-term effects on other important outcomes, such as hospital re-admission rates or prognostic biomarkers.
Khunti, Kamlesh; Stone, Margaret; Paul, Sanjoy; Baines, Jan; Gisborne, Louise; Farooqi, Azhar; Luan, Xiujie; Squire, Iain
2007-11-01
To evaluate the effect of a disease management programme for patients with coronary heart disease (CHD) and chronic heart failure (CHF) in primary care. A cluster randomised controlled trial of 1316 patients with CHD and CHF from 20 primary care practices in the UK was carried out. Care in the intervention practices was delivered by specialist nurses trained in the management of patients with CHD and CHF. Usual care was delivered by the primary healthcare team in the control practices. At follow up, significantly more patients with a history of myocardial infarction in the intervention group were prescribed a beta-blocker compared to the control group (adjusted OR 1.43, 95% CI 1.19 to 1.99). Significantly more patients with CHD in the intervention group had adequate management of their blood pressure (<140/85 mm Hg) (OR 1.61, 95% CI 1.22 to 2.13) and their cholesterol (<5 mmol/l) (OR 1.58, 95% CI 1.05 to 2.37) compared to those in the control group. Significantly more patients with an unconfirmed diagnosis of CHF had a diagnosis of left ventricular systolic dysfunction confirmed (OR 4.69, 95% CI 1.88 to 11.66) or excluded (OR 3.80, 95% CI 1.50 to 9.64) in the intervention group compared to the control group. There were significant improvements in some quality-of-life measures in patients with CHD in the intervention group. Disease management programmes can lead to improvements in the care of patients with CHD and presumed CHF in primary care.
Otaki, Yoichiro; Watanabe, Tetsu; Takahashi, Hiroki; Narumi, Taro; Kadowaki, Shinpei; Honda, Yuki; Arimoto, Takanori; Shishido, Tetsuro; Miyamoto, Takuya; Konta, Tsuneo; Kubota, Isao
2014-05-01
Cardio-renal anemia syndrome (CRAS) has begun to gather attention as a vicious circle since chronic heart failure (CHF), chronic kidney disease (CKD), and anemia are all able to be caused and exacerbated by each other. However, it remains unclear whether renal tubular damage (RTD), another type of kidney dysfunction, is associated with this vicious circle. The aim of the present study was to assess the association of RTD with CRAS in patients with CHF. We included 300 consecutive patients with CHF. RTD was defined as a urinary β2-microglobulin to creatinine ratio ≥ 300 μg/g. Patients with RTD had lower serum iron and higher levels of high sensitivity C-reactive protein than those without it. Multivariate logistic analysis showed that RTD was closely associated with anemia in patients with CHF, after adjustment for confounding factors. During a median period of 1,098 days, there were 86 cardiac events, including 14 cardiac deaths and 72 re-hospitalizations for worsening heart failure. Net reclassification improvement was significantly improved by addition of RTD to the model including age, New York Heart Association functional class, brain natriuretic peptide, anemia, and CKD. All patients were divided into 3 groups: CRAS+RTD group, CRAS group, and control group. Kaplan-Meier analysis demonstrated that CRAS+RTD had the greatest risk in patients with CHF. RTD was associated with normocytic anemia, accompanying iron deficiency and inflammation. RTD added prognostic information to conventional CRAS, suggesting the importance of RTD in cardio-renal anemia interaction. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lee, Jaemin; Lee, Junmyung; Lee, Hyun Woo
The anti-adhesive characteristics of a plasma-modified silicon mold surface for nanoimprint lithography are presented. Both CHF{sub 3}/O{sub 2} and C{sub 4}F{sub 8}/O{sub 2} plasma were used to form an anti-adhesive layer on silicon mold surfaces. The gas mixing ratios of CHF{sub 3}/O{sub 2} and C{sub 4}F{sub 8}/O{sub 2} were experimentally changed between 0% and 80% to optimize the plasma conditions to obtain a low surface energy of the silicon mold. The plasma characteristics were examined by optical emission spectroscopy (OES). In order to investigate the changes in surface energy and surface chemistry of the anti-adhesive layer during repeated demolding cycles,more » contact angle measurements and X-ray photoelectron spectroscopy (XPS) were performed on the plasma-modified silicon mold surface. Simultaneously, the surface morphology of the demolded resists was evaluated by field-emission scanning electron microscope (FE-SEM) in order to examine the effect of the anti-adhesive layers on the duplicated patterns of the resists. It was observed that the anti-adhesive layer formed by CHF{sub 3}/O{sub 2} plasma treatment was worn out more easily during repeated demolding cycles than the film formed by C{sub 4}F{sub 8}/O{sub 2} plasma treatment, because CHF{sub 3}/O{sub 2} gas plasma formed a thinner plasma-polymerized film over the same plasma treatment time.« less
Okutsu, Mitsuharu; Call, Jarrod A.; Lira, Vitor A.; Zhang, Mei; Donet, Jean A.; French, Brent A.; Martin, Kyle S.; Peirce-Cottler, Shayn M.; Rembold, Christopher M.; Annex, Brian H.; Yan, Zhen
2014-01-01
Background Congestive heart failure (CHF) is a leading cause of morbidity and mortality, and oxidative stress has been implicated in the pathogenesis of cachexia (muscle wasting) and the hallmark symptom, exercise intolerance. We have previously shown that a nitric oxide (NO)-dependent antioxidant defense renders oxidative skeletal muscle resistant to catabolic wasting. Here, we aimed to identify and determine the functional role of the NO-inducible antioxidant enzyme(s) in protection against cardiac cachexia and exercise intolerance in CHF. Methods and Results We demonstrated that systemic administration of endogenous nitric oxide donor S-Nitrosoglutathione in mice blocked the reduction of extracellular superoxide dismutase (EcSOD) protein expression, the induction of MAFbx/Atrogin-1 mRNA expression and muscle atrophy induced by glucocorticoid. We further showed that endogenous EcSOD, expressed primarily by type IId/x and IIa myofibers and enriched at endothelial cells, is induced by exercise training. Muscle-specific overexpression of EcSOD by somatic gene transfer or transgenesis [muscle creatine kinase (MCK)-EcSOD] in mice significantly attenuated muscle atrophy. Importantly, when crossbred into a mouse genetic model of CHF [α-myosin heavy chain (MHC)-calsequestrin] MCK-EcSOD transgenic mice had significant attenuation of cachexia with preserved whole body muscle strength and endurance capacity in the absence of reduced heart failure. Enhanced EcSOD expression significantly ameliorated CHF-induced oxidative stress, MAFbx/Atrogin-1 mRNA expression, loss of mitochondria and vascular rarefaction in skeletal muscle. Conclusions EcSOD plays an important antioxidant defense function in skeletal muscle against cardiac cachexia and exercise intolerance in CHF. PMID:24523418
W. Zhu; Carl J. Houtman; J.Y. Zhu; Roland Gleisner; K.F. Chen
2012-01-01
A combined hydrolysis factor (CHF) was developed to predict xylan hydrolysis during pretreatments of native aspen (Populus tremuloides) wood chips. A natural extension of previously developed kinetic models allowed us to account for the effect of catalysts by dilute acid and two sulfite pretreatments at different pH values....
ERIC Educational Resources Information Center
Heneman, Karrie; Junge, Sharon K.; Schneider, Connie; Zidenberg-Cherr, Sheri
2008-01-01
Objectives: The purpose of this pilot project was to evaluate the effect of the Improving Children's Health through Farming, Food, and Fitness Program (CHF3) on the dietary knowledge and habits of participating children. Methods: The CHF3 program aims to 1) establish salad bars and integrate nutrition messages into cafeteria activities; 2) develop…
Congestive heart failure patients report conflict with their physicians.
Zickmund, Susan L; Blasiole, Julie A; Brase, Venture; Arnold, Robert M
2006-09-01
Given the importance of the doctor-patient relationship, we examined the prevalence and nature of patients' perceived conflicts with the physicians caring for their congestive heart failure (CHF). This cross-sectional study recruited patients with CHF in the outpatient and inpatient service of a tertiary referral hospital. Patients completed demographics, semistructured interviews, and surveys of emotional and health status. CHF physiologic measures and comorbidities were abstracted from the medical record. A team of 2 blinded coders analyzed the interviews. Thirty-one percent of the 289 patients reported difficulties with physicians. In the bivariate analysis, only marital status was significantly associated with conflict. Major problems included the providers' poor communication skills (20%), trust in the physicians' competence (18%), and insufficient medical information (16%). Patients identified care outside the tertiary referral hospital (13%) and inadequate communication between physicians (9%) as additional sources of difficulty. Perceived conflict with providers is common in patients with CHF. Patient-level factors, however, did not predict conflict, which differs from our previous findings with hepatitis C patients. Perceived conflict is troubling because it can undermine the trust in the doctor-patient relationship, thereby weakening the therapeutic bond necessary to care for this sick and often vulnerable population.
Tsutamoto, T; Wada, A; Maeda, K; Mabuchi, N; Hayashi, M; Tsutsui, T; Ohnishi, M; Fujii, M; Matsumoto, T; Yamamoto, T; Takayama, T; Kinoshita, M
2001-12-01
Cardiac natriuretic peptides may induce apoptosis in myocytes; however, the relationship between plasma levels of cardiac natriuretic peptides and those of soluble Fas (sFas) and tumor necrosis factor (TNF)-alpha remains unknown in patients with congestive heart failure (CHF). We measured plasma levels of sFas and TNF-alpha and those of atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), norepinephrine, and endothelin 1 in 96 patients with CHF (ejection fraction < 45%). The patients were monitored for 3 years. Plasma levels of sFas and TNF-alpha increased with the severity of CHF. There was no significant correlation between sFas plasma levels and those of ANP and BNP. Cox proportional hazard analysis showed that high levels of sFas (P = .009) and BNP (P < .0001) and a low ejection fraction (P = .019) were independent significant prognostic predictors. There is no significant correlation between cardiac natriuretic peptide and sFas levels in plasma. Plasma sFas is a useful prognostic marker independent of neurohumoral factors, suggesting that immune activation and/or apoptosis play a significant role in the pathogenesis of CHF.
Effect of carvedilol on plasma adiponectin concentration in patients with chronic heart failure.
Yamaji, Masayuki; Tsutamoto, Takayoshi; Tanaka, Toshinari; Kawahara, Chiho; Nishiyama, Keizo; Yamamoto, Takashi; Fujii, Masanori; Horie, Minoru
2009-06-01
Patients with a high plasma adiponectin have a poor prognosis in chronic heart failure (CHF). Angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers are reported to increase the plasma adiponectin concentration, but the effect of beta-blockers on plasma adiponectin in patients with CHF remains unknown. Blood samples were collected at before and 6 months after administration of carvedilol in 44 CHF patients. The hemodynamic parameters, echocardiography, plasma concentrations of brain natriuretic peptide (BNP), norepinephrine and adiponectin were measured. Six months after treatment, there were significantly decreased plasma concentrations of adiponectin (15.8 +/-1.4 to 11.0 +/-1.1 microg/ml, P<0.0001), BNP and norepinephrine and increased left ventricular ejection fraction (LVEF). On stepwise multivariable analyses, a higher plasma adiponectin concentration before treatment (rs=-0.561, P<0.0001) was a significant independent predictor of a greater decrease in adiponectin concentration and the decrease in plasma adiponectin concentration was significantly correlated with the improvement of LVEF (r=-0.561, P<0.0001). These findings indicate that carvedilol decreases plasma adiponectin concentration and that the decrease in plasma adiponectin is associated with the improvement of LVEF after treatment with carvedilol in CHF patients.
Additive Benefits of Twice Forest Bathing Trips in Elderly Patients with Chronic Heart Failure.
Mao, Gen Xiang; Cao, Yong Bao; Yang, Yan; Chen, Zhuo Mei; Dong, Jian Hua; Chen, Sha Sha; Wu, Qing; Lyu, Xiao Ling; Jia, Bing Bing; Yan, Jing; Wang, Guo Fu
2018-02-01
Chronic heart failure (CHF), a clinical syndrome resulting from the consequences of various cardiovascular diseases (CVDs), is increasingly becoming a global cause of morbidity and mortality. We had earlier demonstrated that a 4-day forest bathing trip can provide an adjunctive therapeutic influence on patients with CHF. To further investigate the duration of the impact and the optimal frequency of forest bathing trips in patients with CHF, we recruited those subjects who had experienced the first forest bathing trip again after 4 weeks and randomly categorized them into two groups, namely, the urban control group (city) and the forest bathing group (forest). After a second 4-day forest bathing trip, we observed a steady decline in the brain natriuretic peptide levels, a biomarker of heart failure, and an attenuated inflammatory response as well as oxidative stress. Thus, this exploratory study demonstrated the additive benefits of twice forest bathing trips in elderly patients with CHF, which could further pave the way for analyzing the effects of such interventions in CVDs. Copyright © 2018 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.
Decrease of cardiac chaos in congestive heart failure
NASA Astrophysics Data System (ADS)
Poon, Chi-Sang; Merrill, Christopher K.
1997-10-01
The electrical properties of the mammalian heart undergo many complex transitions in normal and diseased states. It has been proposed that the normal heartbeat may display complex nonlinear dynamics, including deterministic chaos,, and that such cardiac chaos may be a useful physiological marker for the diagnosis and management, of certain heart trouble. However, it is not clear whether the heartbeat series of healthy and diseased hearts are chaotic or stochastic, or whether cardiac chaos represents normal or abnormal behaviour. Here we have used a highly sensitive technique, which is robust to random noise, to detect chaos. We analysed the electrocardiograms from a group of healthy subjects and those with severe congestive heart failure (CHF), a clinical condition associated with a high risk of sudden death. The short-term variations of beat-to-beat interval exhibited strongly and consistently chaotic behaviour in all healthy subjects, but were frequently interrupted by periods of seemingly non-chaotic fluctuations in patients with CHF. Chaotic dynamics in the CHF data, even when discernible, exhibited a high degree of random variability over time, suggesting a weaker form of chaos. These findings suggest that cardiac chaos is prevalent in healthy heart, and a decrease in such chaos may be indicative of CHF.
Giallauria, Francesco; Smart, Neil Andrew; Cittadini, Antonio; Vigorito, Carlo
2016-10-14
Exercise training (ET) is strongly recommended in patients with chronic heart failure (CHF). Moderate-intensity aerobic continuous ET is the best established training modality in CHF patients. In the last decade, however, high-intensity interval exercise training (HIIT) has aroused considerable interest in cardiac rehabilitation community. Basically, HIIT consists of repeated bouts of high-intensity exercise alternated with recovery periods. In CHF patients, HIIT exerts larger improvements in exercise capacity compared to moderate-continuous ET. These results are intriguing, mostly considering that better functional capacity translates into an improvement of symptoms and quality of life. Notably, HIIT did not reveal major safety issues; although CHF patients should be clinically stable, have had recent exposure to at least regular moderate-intensity exercise, and appropriate supervision and monitoring during and after the exercise session are mandatory. The impact of HIIT on cardiac dimensions and function and on endothelial function remains uncertain. HIIT should not replace other training modalities in heart failure but should rather complement them. Combining and tailoring different ET modalities according to each patient's baseline clinical characteristics (i.e. exercise capacity, personal needs, preferences and goals) seem the most astute approach to exercise prescription.
Carels, Robert A
2004-02-01
Congestive heart failure significantly compromises quality of life by contributing to severe physical, role, and social functioning impairment as well as increased psychological distress. Previous research examining quality of life in CHF patients has typically been conducted using global self-report instruments that may exceed a patient's ability to accurately recall their experiences. This investigation examines the impact of disease severity, functional status, and level of depression on daily quality of life (i.e., mean level and variability) in CHF patients during a 2-week monitoring period. Indices of quality of life included emotional and physical quality of life, social support and conflict, positive and negative mood, and coping responses. Fifty-eight patients with CHF participated in the investigation. Depressive symptoms were positively associated with a number of quality of life indices (i.e., physical and emotional quality of life, social support and conflict, mood, and coping behaviours). Left ventricular ejection fraction and functional impairment had a much weaker association with quality of life. These findings suggest that depressive symptoms may have a greater impact on quality of life in CHF patients than severity of cardiac dysfunction or functional impairment.
Natriuretic peptides and their therapeutic potential in heart failure treatment: An updated review.
Namdari, M; Eatemadi, A; Negahdari, B
2016-09-30
Brain natriuretic peptide (BNP), also known as a B-type natriuretic peptide, is one of the important biomarkers with a proven role in the diagnosis of congestive heart failure (CHF). Researchers from the different clinical field have researched into the performance features of BNP testing in the acute care set-up to assist and improve in diagnosing CHF and in predicting future morbidity and mortality rates. The potency of BNP has also been researched into in cases like myocardial ischemia and infarction, cor pulmonale, and acute pulmonary embolism (PE). Based on their vaso-dilatory and diuretic properties and ability to inhibit renin-angiotensin-aldosterone system, natriuretic peptides are able to provide an efficient technique and mechanism of action in the pathophysiologic framework for CHF treatment and management. Recent clinical studies reported that ularitide, a synthetic form of urodilatin, secreted by kidney may be effective in managing and treatment of decompensated heart failure. It has also been reported that Nesiritide, a recombinant natriuretic peptide has been proven to improve dyspnea and hemodynamic parameters in heart failure patients. This review provides an update on natriuretic peptides and their therapeutic potential in CHF treatment.
Lyon, Jonathan T; Andrews, Lester
2007-06-11
Group 4 transition metal methylidene difluoride complexes (CH2=MF2) are formed by the reaction of methylene fluoride with laser-ablated metal atoms and are isolated in an argon matrix. Isotopic substitution of the CH2F2 precursor and theoretical computations (B3LYP and CCSD) confirm product identifications and assignments. Our calculations indicate that the CH2=MF2 complexes have near C2v symmetry and are considerably more stable than other possible products (CH2(mu-F)MF and CHF=MHF). The primary reaction exothermicity provides more than enough energy to activate the initial bridge-bonded CH2(mu-F)MF products on the triplet potential energy surface to complete an alpha-F transfer to form the very stable CH2=MF2 products. Analogous experiments with CHF3 produce CHF=TiF2, which is not distorted at the C-H bond, whereas the heavier group 4 metals form lower-energy triplet HC/MF3 complexes, which contain weak degenerate C(p)-M(d) pi-bonding interactions. Comparisons are made with the CH2=MHF methylidene species, which showed considerable agostic distortions.
Papadimitriou, Vassileios C; Lazarou, Yannis G; Talukdar, Ranajit K; Burkholder, James B
2011-01-20
Rate coefficients, k, for the gas-phase reactions of Cl atoms and NO(3) radicals with 2,3,3,3-tetrafluoropropene, CF(3)CF═CH(2) (HFO-1234yf), and 1,2,3,3,3-pentafluoropropene, (Z)-CF(3)CF═CHF (HFO-1225ye), are reported. Cl-atom rate coefficients were measured in the fall-off region as a function of temperature (220-380 K) and pressure (50-630 Torr; N(2), O(2), and synthetic air) using a relative rate method. The measured rate coefficients are well represented by the fall-off parameters k(0)(T) = 6.5 × 10(-28) (T/300)(-6.9) cm(6) molecule(-2) s(-1) and k(∞)(T) = 7.7 × 10(-11) (T/300)(-0.65) cm(3) molecule(-1) s(-1) for CF(3)CF═CH(2) and k(0)(T) = 3 × 10(-27) (T/300)(-6.5) cm(6) molecule(-2) s(-1) and k(∞)(T) = 4.15 × 10(-11) (T/300)(-0.5) cm(3) molecule(-1) s(-1) for (Z)-CF(3)C═CHF with F(c) = 0.6. Reaction product yields were measured in the presence of O(2) to be (98 ± 7)% for CF(3)C(O)F and (61 ± 4)% for HC(O)Cl in the CF(3)CF═CH(2) reaction and (108 ± 8)% for CF(3)C(O)F and (112 ± 8)% for HC(O)F in the (Z)-CF(3)CF═CHF reaction, where the quoted uncertainties are 2σ (95% confidence level) and include estimated systematic errors. NO(3) reaction rate coefficients were determined using absolute and relative rate methods. Absolute measurements yielded upper limits for both reactions between 233 and 353 K, while the relative rate measurements yielded k(3)(295 K) = (2.6 ± 0.25) × 10(-17) cm(3) molecule(-1) s(-1) and k(4)(295 K) = (4.2 ± 0.5) × 10(-18) cm(3) molecule(-1) s(-1) for CF(3)CF═CH(2) and (Z)-CF(3)CF═CHF, respectively. The Cl-atom reaction with CF(3)CF═CH(2) and (Z)-CF(3)CF═CHF leads to decreases in their atmospheric lifetimes and global warming potentials and formation of a chlorine-containing product, HC(O)Cl, for CF(3)CF═CH(2). The NO(3) reaction has been shown to have a negligible impact on the atmospheric lifetimes of CF(3)CF═CH(2) and (Z)-CF(3)CF═CHF. The energetics for the reaction of Cl, NO(3), and OH with CF(3)CF═CH(2) and (Z)-CF(3)CF═CHF in the presence of O(2) were investigated using density functional theory (DFT).
Sandri, Marcus; Viehmann, Manuel; Adams, Volker; Rabald, Kristin; Mangner, Norman; Höllriegel, Robert; Lurz, Philipp; Erbs, Sandra; Linke, Axel; Kirsch, Katharina; Möbius-Winkler, Sven; Thiery, Joachim; Teupser, Daniel; Hambrecht, Rainer; Schuler, Gerhard; Gielen, Stephan
2016-03-01
A reduction in number and function of endothelial progenitor cells (EPCs) occurs in both physiologic aging and chronic heart failure (CHF). We assessed whether disease and aging have additive effects on EPCs or whether beneficial effects of exercise training are diminished in old age. We randomized 60 patients with stable CHF and 60 referent controls to a training or a control group. To detect possible aging effects we included subjects below 55 (young) and above 65 years (older). Subjects in the training group exercised four times daily at 60% to 70% of VO2max for four weeks under supervision. At baseline and after the intervention the number and function of EPCs were assessed. As compared with young referent controls, older referent controls showed at baseline a reduced EPC number (young: 190 ± 37 CD34/KDR positive cells/ml blood; older: 131 ± 26 CD34/KDR positive cells/ml blood; p < 0.05) and function (young: 230 ± 41 migrated cells/1000 plated cells; older: 185 ± 28 cells/1000 plated cells; p < 0.05). In young and older CHF patients EPC-number (young: 85 ± 21 CD34/KDR positive cells/ml blood; older: 78 ± 20 CD34/KDR positive cells/ml blood) and EPC-function (young: 113 ± 26 cells/1000 plated cells; older: 120 ± 27 cells/1000 plated cells) were impaired. As a result of exercise training, EPC function improved by 24% in older referent controls (p < 0.05), while it remained unchanged in young training referent controls and controls respectively. In young and older patients with CHF four weeks of exercise training resulted in a significant improvement in EPC numbers and EPC function (young: number +66% function +43%; p < 0.05; older: number +69% function +36%; p < 0.05). These results were accompanied by a significant increase in flow mediated dilatation in the training groups of young/older CHF patients and in older referent controls. Four weeks of exercise training are effective in improving EPC number and EPC function in CHF patients. These training effects were not impaired among older patients, emphasizing the potentials of rehabilitation interventions in a patient group where CHF has a high prevalence. © The European Society of Cardiology 2015.
Pathogenic Gut Flora in Patients With Chronic Heart Failure.
Pasini, Evasio; Aquilani, Roberto; Testa, Cristian; Baiardi, Paola; Angioletti, Stefania; Boschi, Federica; Verri, Manuela; Dioguardi, Francesco
2016-03-01
The goal of this study was to measure the presence of pathogenic gut flora and intestinal permeability (IP) and their correlations with disease severity, venous blood congestion, and inflammation in patients with chronic heart failure (CHF). Evidence suggests that translocation of gut flora and/or their toxins from the intestine to the bloodstream is a possible trigger of systemic CHF inflammation. However, the relation between pathogenic gut flora and CHF severity, as well as IP, venous blood congestion as right atrial pressure (RAP), and/or systemic inflammation (C-reactive protein [CRP]), is still unknown. This study analyzed 60 well-nourished patients in stable condition with mild CHF (New York Heart Association [NYHA] functional class I to II; n = 30) and moderate to severe CHF (NYHA functional class III to IV; n = 30) and matched healthy control subjects (n = 20). In all subjects, the presence and development in the feces of bacteria and fungi (Candida species) were measured; IP according to cellobiose sugar test results was documented. The study data were then correlated with RAP (echocardiography) and systemic inflammation. Compared with normal control subjects, the entire CHF population had massive quantities of pathogenic bacteria and Candida such as Campylobacter (85.3 ± 3.7 CFU/ml vs. 1.0 ± 0.3 CFU/ml; p < 0.001), Shigella (38.9 ± 12.3 CFU/ml vs. 1.6 ± 0.2 CFU/ml; p < 0.001), Salmonella (31.3 ± 9.1 CFU/ml vs 0 CFU/ml; p < 0.001), Yersinia enterocolitica (22.9 ± 6.3 CFU/ml vs. 0 CFU/ml; p < 0.0001), and Candida species (21.3 ± 1.6 CFU/ml vs. 0.8 ± 0.4 CFU/ml; p < 0.001); altered IP (10.2 ± 1.2 mg vs. 1.5 ± 0.8 mg; p < 0.001); and increased RAP (12.6 ± 0.6 mm Hg) and inflammation (12.5 ± 0.6 mg/dl). These variables were more pronounced in patients with moderate to severe NYHA functional classes than in patients with the mild NYHA functional class. Notably, IP, RAP, and CRP were mutually interrelated (IP vs. RAP, r = 0.55; p < 0.0001; IP vs. CRP, r = 0.78; p < 0.0001; and RAP vs. CRP, r = 0.78; p < 0.0001). This study showed that patients with CHF may have intestinal overgrowth of pathogenic bacteria and Candida species and increased IP associated with clinical disease severity, venous blood congestion, and inflammation. Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.
Haynes, Andrew; Linden, Matthew D; Chasland, Lauren C; Nosaka, Kazunori; Maiorana, Andrew; Dawson, Ellen A; Dembo, Lawrence H; Naylor, Louise H; Green, Daniel J
2017-06-01
Evidence-based guidelines recommend exercise therapy for patients with chronic heart failure (CHF). Such patients have increased atherothrombotic risk. Exercise can transiently increase platelet activation and reactivity and decrease vascular function in healthy participants, although data in CHF are scant. Eccentric (ECC) cycling is a novel exercise modality that may be particularly suited to patients with CHF, but the acute impacts of ECC cycling on platelet and vascular function are currently unknown. Our null hypothesis was that ECC and concentric (CON) cycling, performed at matched external workloads, would not induce changes in platelet or vascular function in patients with CHF. Eleven patients with heart failure with reduced ejection fraction (HFrEF) took part in discrete bouts of ECC and CON cycling. Before and immediately after exercise, vascular function was assessed by measuring diameter and flow-mediated dilation (FMD) of the brachial artery. Platelet function was measured by the flow cytometric determination of glycoprotein IIb/IIIa activation and granule exocytosis in the presence and absence of platelet agonists. ECC cycling increased baseline artery diameter (pre: 4.0 ± 0.8 mm vs. post: 4.2 ± 0.7 mm; P = 0.04) and decreased FMD%. When changes in baseline artery diameter were accounted for, the decrease in FMD post-ECC cycling was no longer significant. No changes were apparent after CON. Neither ECC nor CON cycling resulted in changes to any platelet-function measures (all P > 0.05). These results suggest that both ECC and CON cycling, at a moderate intensity and short duration, can be performed by patients with HFrEF without detrimental impacts on vascular or platelet function. NEW & NOTEWORTHY This is the first evidence to indicate that eccentric (ECC) cycling can be performed relatively safely by patients with chronic heart failure (CHF), as it did not result in impaired vascular or platelet function compared with conventional cycling. This is important, as acute exercise can transiently increase atherothrombotic risk, and ECC cycling is a novel exercise modality that may be particularly suited to patients with CHF. Copyright © 2017 the American Physiological Society.
Determinants of community health fund membership in Tanzania: a mixed methods analysis.
Macha, Jane; Kuwawenaruwa, August; Makawia, Suzan; Mtei, Gemini; Borghi, Josephine
2014-11-20
In many developing countries, initiatives are underway to strengthen voluntary community based health insurance as a means of expanding access to affordable care among the informal sector. However, increasing coverage with voluntary health insurance in low income settings can prove challenging. There are limited studies on determinants of enrolling in these schemes using mixed methods. This study aims to shed light on the characteristics of those joining a community health fund, a type of community based health insurance, in Tanzania and the reasons for their membership and subsequent drop out using mixed methods. A cross sectional survey of households in four rural districts was conducted in 2008, covering a total of 1,225 (524 members of CHF and 701 non-insured) households and 7,959 individuals. In addition, 12 focus group discussions were carried out with CHF members, non-scheme members and members of health facility governing committees in two rural districts. Logistic regression was used to assess the determinants of CHF membership while thematic analysis was done to analyse qualitative data. The quantitative analysis revealed that the three middle income quintiles were more likely to enrol in the CHF than the poorest and the richest. CHF member households were more likely to be large, and headed by a male than uninsured households from the same areas. The qualitative data supported the finding that the poor rather than the poorest were more likely to join as were large families and of greater risk of illness, with disabilities or persons with chronic diseases. Households with elderly members or children under-five years were also more likely to enrol. Poor understanding of risk pooling deterred people from joining the scheme and was the main reason for not renewing membership. On the supply side, poor quality of public care services, the limited benefit package and a lack of provider choice were the main factors for low enrolment. Determinants of CHF membership are diverse and improving the quality of health services and expanding the benefit package should be prioritised to expand voluntary health insurance coverage.
Wu, Victor Chien-Chia; Chang, Shang-Hung; Kuo, Chang-Fu; Liu, Jia-Rou; Chen, Shao-Wei; Yeh, Yung-Hsin; Luo, Shue-Fen; See, Lai-Chu
2018-06-01
The literature on suicide mortality rates in patients with cardiovascular diseases (CVDs) is limited. Taiwan National Health Insurance Research Database and Taiwan Death Registry were retrieved for patients with the 5 CVDs: congestive heart failure (CHF), acute myocardial infarction (AMI), ischemic stroke (IS), hemorrhagic stroke (HS), and pacemaker implantation (PMI) between January 1, 2001, and December 31, 2015. We excluded patients younger than 15 years old. The primary outcome was suicidal death. The standardized mortality ratio (SMR) was used to compare the risk of suicidal death in the 5 CVDs to the general population. From 2001 to 2015, there were 212,206 patients with CHF, 178,894 patients with AMI, 475,359 patients with IS, 189,555 patients with HS, and 64,173 patients with PMI. The suicide death rate per 100,000 person-year, 95% CI was 59.6 (54.5-64.8) for those with CHF, 44.6 (40.1-49.1) for AMI, 57.6 (54.7-60.5) for IS, 44.6 (40.2-49.0) for HS, 54.0 (45.9-62.0) for PMI, and 20.3 (20.1-20.4) for the general population. Patients with CHF patients had the highest SMR (2.10), followed by IS (1.96), PMI (1.86), HS (1.65), and AMI (1.46). The SMRs for patients with CVDs peaked at year 2 after the diagnosis, declined for patients with AMI, IS, and HS, increased and decreased for PMI alternately, and reached very similar values all five CVDs after 10th year after the diagnosis. Patients with acute CVD with AMI, IS, and HS had suicide death rates peaked early after diagnosis, but patients with chronic CVD with CHF and PMI had suicide death rates that increased progressively. In addition, patients with PMI, CHF, IS had highest association with psychiatric illness and patients with PMI who were of young to middle age had highest suicide death rate. Copyright © 2018 Elsevier B.V. All rights reserved.
Krum, Henry; Mohacsi, Paul; Katus, Hugo A; Tendera, Michael; Rouleau, Jean-Lucien; Fowler, Michael B; Coats, Andrew J; Roecker, Ellen B; Packer, Milton
2006-01-01
The beneficial effects of beta-blockers and aldosterone receptor antagonists are now well established in patients with severe systolic chronic heart failure (CHF). However, it is unclear whether beta-blockers are able to provide additional benefit in patients already receiving aldosterone antagonists. We therefore examined this question in the COPERNICUS study of 2289 patients with severe CHF receiving the beta1-beta2/alpha1 blocker carvedilol compared with placebo. Patients were divided post hoc into subgroups according to whether they were receiving spironolactone (n = 445) or not (n = 1844) at baseline. Consistency of the effect of carvedilol versus placebo was examined for these subgroups with respect to the predefined end points of all-cause mortality, death or CHF-related hospitalizations, death or cardiovascular hospitalizations, and death or all-cause hospitalizations. The beneficial effect of carvedilol was similar among patients who were or were not receiving spironolactone for each of the 4 efficacy measures. For all-cause mortality, the Cox model hazard ratio for carvedilol compared with placebo was 0.65 (95% CI 0.36-1.15) in patients receiving spironolactone and 0.65 (0.51-0.83) in patients not receiving spironolactone. Hazard ratios for death or all-cause hospitalization were 0.76 (0.55-1.05) versus 0.76 (0.66-0.88); for death or cardiovascular hospitalization, 0.61 (0.42-0.89) versus 0.75 (0.64-0.88); and for death or CHF hospitalization, 0.63 (0.43-0.94) versus 0.70 (0.59-0.84), in patients receiving and not receiving spironolactone, respectively. The safety and tolerability of treatment with carvedilol were also similar, regardless of background spironolactone. Carvedilol remained clinically efficacious in the COPERNICUS study of patients with severe CHF when added to background spironolactone in patients who were practically all receiving angiotensin-converting enzyme inhibitor (or angiotensin II antagonist) therapy. Therefore, the use of spironolactone in patients with severe CHF does not obviate the necessity of additional treatment that interferes with the adverse effects of sympathetic activation, specifically beta-blockade.
Inglis, Sally C; Clark, Robyn A; McAlister, Finlay A; Stewart, Simon; Cleland, John G F
2011-09-01
Telemonitoring (TM) and structured telephone support (STS) have the potential to deliver specialized management to more patients with chronic heart failure (CHF), but their efficacy is still to be proven. The aim of this meta-analysis was to review randomized controlled trials (RCTs) of TM or STS for all-cause mortality and all-cause and CHF-related hospitalizations in patients with CHF, as a non-invasive remote model of a specialized disease-management intervention. We searched all relevant electronic databases and search engines, hand-searched bibliographies of relevant studies, systematic reviews, and meeting abstracts. Two reviewers independently extracted all data. Randomized controlled trials comparing TM or STS to usual care in patients with CHF were included. Studies that included intensified management with additional home or clinic-visits were excluded. Primary outcomes (mortality and hospitalizations) were analysed; secondary outcomes (cost, length of stay, and quality of life) were tabulated. Thirty RCTs of STS and TM were identified (25 peer-reviewed publications (n= 8323) and five abstracts (n= 1482)). Of the 25 peer-reviewed studies, 11 evaluated TM (2710 participants), 16 evaluated STS (5613 participants) with two testing both STS and TM in separate intervention arms compared with usual care. Telemonitoring reduced all-cause mortality {risk ratio (RR) 0.66 [95% confidence interval (CI) 0.54-0.81], P< 0.0001 }and STS showed a similar, but non-significant trend [RR 0.88 (95% CI 0.76-1.01), P= 0.08]. Both TM [RR 0.79 (95% CI 0.67-0.94), P= 0.008], and STS [RR 0.77 (95% CI 0.68-0.87), P< 0.0001] reduced CHF-related hospitalizations. Both interventions improved quality of life, reduced costs, and were acceptable to patients. Improvements in prescribing, patient-knowledge and self-care, and functional class were observed. Telemonitoring and STS both appear effective interventions to improve outcomes in patients with CHF. Systematic Review Number: Cochrane Database of Systematic Reviews. 2008:Issue 3. Art. No.: CD007228. DOI: 10.1002/14651858.CD007228.
Serum Uric Acid level in the severity of Congestive Heart Failure (CHF)
khan, Adnan; Shah, Mohammad Hassan; khan, Sarbiland; Shamim, Umama; Arshad, Sanan
2017-01-01
Background and Objective: It has been observed that in a clinical condition like hypoxemia there is an increase in the serum Uric acid level. The objective of our study was to find out the relationship between serum uric acid levels in the severity of Heart failure. Methods: We analyze 285 patients with a diagnosis of Congestive heart failure admitted in Lady Reading Hospital Peshawar from March 1st to August 2016. Age group of patients was 17- 67 years. New York Health Association (NYHA) scoring were used to access the severity of Congestive Heart Failure. Serum UA level >7.0 mg/dl was considered high. Results: Total 285 patients with CHF were analyzed with a mean age of 54±2.8 years in which males were 65.96% and 34.03% were female. 40% were in class II of New York Health Association (NYHA), 32.63% in class III and 25.61% in class IV and 1.75% were in class I. Out of 285, 59.29% met the definition of hyperuricemia. In which 83.43% were male and 16.57% were female. Most of the Hyperuricemic patients 62.13% were in age group of 51- 60 years, with a mean age of 57±4.5 years. We found a significant correlation between uric acid level and BNP (p= <0.001), and use of diuretics (p=<0.001). 34.93% of the Hyperuricemic CHF patients were in NYHA III and NYHA IV whose SUA was above 8 mg/dl as compared to 31.57% Hyperuricemic CHF patients whose SUA was below 8 mg/dl. Conclusion: High serum Uric acid was observed in 59.29% of patients with CHF. The observed significant correlation between UA level and some established prognostic markers in these patients may indicate that serum UA could provide additional prognostic information in this population. SUA as a marker can be measured anywhere at a low cost to help identify high-risk patients with CHF. Lowing uric acid is expected to be a new approach for prevention and therapy of HF. PMID:28523032
Yamanushi, Tomoko T; Kabuto, Hideaki; Hirakawa, Eiichiro; Janjua, Najma; Takayama, Fusako; Mankura, Mitsumasa
2014-04-01
This study assessed the effects of eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA) on normal cardiac function (part 1) and congestive heart failure (CHF) (part 2) through electrocardiogram analysis and determination of EPA, DHA, and arachidonic acid (AA) concentrations in rat hearts. In part 2, pathologic assessments were also performed. For part 1 of this study, 4-wk-old male rats were divided into a control group and 2 experimental groups. The rats daily were orally administered (1 g/kg body weight) saline, EPA-ethyl ester (EPA-Et; E group), or DHA-ethyl ester (DHA-Et; D group), respectively, for 28 d. ECGs revealed that QT intervals were significantly shorter for groups E and D compared with the control group (P ≤ 0.05). Relative to the control group, the concentration of EPA was higher in the E group and concentrations of EPA and DHA were higher in the D group, although AA concentrations were lower (P ≤ 0.05). In part 2, CHF was produced by subcutaneous injection of monocrotaline into 5-wk-old rats. At 3 d before monocrotaline injection, rats were administered either saline, EPA-Et, or DHA-Et as mentioned above and then killed at 21 d. The study groups were as follows: normal + saline (control), CHF + saline (H group), CHF + EPA-Et (HE group), and CHF + DHA-Et (HD group). QT intervals were significantly shorter (P ≤ 0.05) in the control and HD groups compared with the H and HE groups. Relative to the H group, concentrations of EPA were higher in the HE group and those of DHA were higher in the control and HD groups (P ≤ 0.05). There was less mononuclear cell infiltration in the myocytes of the HD group than in the H group (P = 0.06). The right ventricles in the H, HE, and HD groups showed significantly increased weights (P ≤ 0.05) compared with controls. The administration of EPA-Et or DHA-Et may affect cardiac function by modification of heart fatty acid composition, and the administration of DHA-Et may ameliorate CHF.
Reis, Hugo V; Borghi-Silva, Audrey; Catai, Aparecida M; Reis, Michel S
2014-01-01
Chronic heart failure (CHF) leads to exercise intolerance. However, non-invasive ventilation is able to improve functional capacity of patients with CHF. The aim of this study was to evaluate the effectiveness of continuous positive airway pressure (CPAP) on physical exercise tolerance and heart rate variability (HRV) in patients with CHF. Method : Seven men with CHF (62 ± 8 years) and left ventricle ejection fraction of 41 ± 8% were submitted to an incremental symptom-limited exercise test (IT) on the cicloergometer. On separate days, patients were randomized to perform four constant work rate exercise tests to maximal tolerance with and without CPAP (5 cmH2O) in the following conditions: i) at 50% of peak work rate of IT; and ii) at 75% of peak work rate of IT. At rest and during these conditions, instantaneous heart rate (HR) was recorded using a cardiofrequencimeter and HRV was analyzed in time domain (SDNN and RMSSD indexes). For statistical procedures, Wilcoxon test or Kruskall-Wallis test with Dunn's post-hoc were used accordingly. In addition, categorical variables were analysed through Fischer's test (p<0.05). There were significant improvements in exercise tolerance at 75% of peak work rate of IT with CPAP (405 ± 52 vs. 438 ± 58 s). RMSSD indexes were lower during exercise tests compared to CPAP at rest and with 50% of peak work rate of IT. These data suggest that CPAP appears to be a useful strategy to improve functional capacity in patients with CHF. However, the positive impact of CPAP did not generate significant changes in the HRV during physical exercises.
Buja, Alessandra; Damiani, Gianfranco; Gini, Rosa; Visca, Modesta; Federico, Bruno; Donato, Daniele; Francesconi, Paolo; Marini, Alessandro; Donatini, Andrea; Brugaletta, Salvatore; Baldo, Vincenzo; Donata Bellentani, Maria
2014-01-01
Our interest in chronic conditions is due to the fact that, worldwide, chronic diseases have overtaken infectious diseases as the leading cause of death and disability, so their management represents an important challenge for health systems. The aim of this study was to compare the performance of primary health care services in managing diabetes, congestive heart failure (CHF) and coronary heart disease (CHD), by age group. This population-based retrospective cohort study was conducted in Italy, enrolling 1,948,622 residents ≥ 16 years old. A multilevel regression model was applied to analyze compliance to care processes with explanatory variables at both patient and district level, using age group as an independent variable, and adjusting for sex, citizenship, disease duration, and Charlson index on the first level, and for District Health Unit on the second level. The quality of chronic disease management showed an inverted U-shaped relationship with age. In particular, our findings indicate lower levels for young adults (16-44 year-olds), adults (45-64), and oldest old (+85) than for patients aged 65-74 in almost all quality indicators of CHD, CHF and diabetes management. Young adults (16-44 y), adults (45-64 y), the very old (75-84 y) and the oldest old (+85 y) patients with CHD, CHF and diabetes are less likely than 65-74 year-old patients to be monitored and treated using evidence-based therapies, with the exceptions of echocardiographic monitoring for CHF in young adult patients, and renal monitoring for CHF and diabetes in the very old. Our study shows that more effort is needed to ensure that primary health care systems are sensitive to chronic conditions in the young and in the very elderly.
Ashton, Emma; Windebank, Emma; Skiba, Marina; Reid, Christopher; Schneider, Hans; Rosenfeldt, Franklin; Tonkin, Andrew; Krum, Henry
2011-02-03
Statins are often prescribed for prevention of atherosclerotic outcomes in patients who have chronic heart failure (CHF), if this has an ischaemic etiology. These agents may also possess additional properties, independent of effects on blood lipid levels, which may have an effect on cardiac remodeling. However, beneficial effects were not observed in the recent UNIVERSE trial. We prospectively planned a sub-study of UNIVERSE to explore relevant mechanistic effects of rosuvastatin, including effects on collagen turnover and plasma coenzyme Q10 (CoQ) levels. Additionally, CoQ levels in CHF patients receiving chronic statin therapy were measured. CoQ levels were significantly reduced after 26 weeks of rosuvastatin statin therapy (n = 32), compared to placebo (n = 37) in CHF patients in UNIVERSE trial. Patients with CHF (n = 56) matched for age, gender and severity of disease who had been taking statins for 12 months or longer had CoQ levels of 847 ± 344 nmol/L, significantly lower than 1065.4 ± 394 nmol/L in UNIVERSE patients at baseline (p = 0.0001). Serum types I and III N-terminal procollagen peptide (PINP and PIIINP), measures of collagen turnover which can contribute to cardiac fibrosis were significantly increased in the rosuvastatin group compared to baseline in UNIVERSE patients (PINP: p = 0.03, PIIINP: p = 0.001). In conclusion putative beneficial effects of statin therapy on cardiac remodeling in UNIVERSE may have been negated by increases in collagen turnover markers as well as a reduction in plasma CoQ levels in these patients with CHF. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.
Akkafa, Feridun; Halil Altiparmak, Ibrahim; Erkus, Musluhittin Emre; Aksoy, Nurten; Kaya, Caner; Ozer, Ahmet; Sezen, Hatice; Oztuzcu, Serdar; Koyuncu, Ismail; Umurhan, Berrin
2015-01-01
Sirtuin-1 (SIRT1) is a longevity factor in mammals initiating the cell survival mechanisms, and preventing ischemic injury in heart. In the etiopathogenesis of heart failure (HF), impairment in cardiomyocyte survival is a notable factor. Oxidative stress comprises a critical impact on cardiomyocyte lifespan in HF. The aim of the present study was to investigate SIRT1 expression in patients with compensated (cHF) and decompensated HF (dHF), and its correlation with oxidative stress. SIRT1 expression in peripheral leukocytes was examined using quantitative RT-PCR in 163 HF patients and 84 controls. Serum total oxidant status (TOS) and total antioxidant status (TAS) were measured via colorimetric assays, and oxidative stress index (OSI) was calculated. Lipid parameters were also determined by routine laboratory methods. SIRT1 mRNA expression was significantly downregulated in HF with more robust decrease in dHF (p=0.002, control vs cHF; p<0.001, control vs dHF). Markedly increased oxidative stress defined as elevated TOS, OSI and low TAS levels were detected in HF patients comparing with the controls (TAS; p=0.010, control vs cHF, p=0.045 control vs dHF, TOS; p=0.004 control vs cHF; p<0.001 control vs dHF, OSI; p<0.001 for both comparisons, respectively). With SIRT1 expression levels, TAS, TOS, OSI, and high density lipoprotein levels in cHF and dHF were determined correlated. SIRT1 expression were significantly reduced in both HF subtypes, particularly in dHF. SIRT1 expression was correlated with the oxidant levels and antioxidant capacity. Data suggest that SIRT1 may have a significant contribution in regulation of oxidant/antioxidant balance in HF etiology and compensation status. PMID:26233702
Susa, Takehisa; Kobayashi, Shigeki; Tanaka, Takeo; Murakami, Wakako; Akashi, Shintaro; Kunitsugu, Ichiro; Okuda, Shinichi; Doi, Masahiro; Wada, Yasuaki; Nao, Tomoko; Yamada, Jutaro; Ueyama, Takeshi; Okamura, Takayuki; Yano, Masafumi; Matsuzaki, Masunori
2012-01-01
The authors recently reported that urinary 8-hydroxy-2'-deoxyguanosine (U8-OHdG) derived from cardiac tissue reflects clinical status and cardiac dysfunction severity in patients with chronic heart failure (CHF). The aim of the present study was to investigate whether U8-OHdG levels can accurately predict cardiac events in CHF patients and their response to β-blocker treatment. Plasma brain natriuretic peptide (BNP) and U8-OHdG levels were measured in 186 consecutive CHF patients before discharge. Patients were then prospectively followed (median follow-up, 649 days) with endpoints of cardiac death or hospitalization due to progressive heart failure. From receiver operating characteristic curve analysis, cut-offs were 12.4ng/mg creatinine (Cr) for U8-OHdG and 207pg/ml for BNP. On multivariate Cox analysis, U8-OHdG and BNP were independent predictors of cardiac events. Patients were classified into 4 groups according to U8-OHdG and BNP cut-offs. The hazard ratio for cardiac events in patients with BNP ≥207pg/ml and U8-OHdG ≥12.4ng/mg Cr was 16.2 compared with approximately 4 for patients with only 1 indicator above its respective cut-off. Furthermore, carvedilol therapy was initiated in 30 CHF patients. In responders (≥10% increase in left ventricular ejection fraction [LVEF] or ≥1 class decrease in New York Heart Association [NYHA] class), U8-OHdG levels decreased significantly along with improved NYHA class, LVEF, and BNP levels after treatment. U8-OHdG may be a useful biomarker for predicting cardiac events and evaluating β-blocker therapy effectiveness in CHF patients.
Incici, Erol; Matuliene, Giedre; Hüsler, Jürg; Salvi, Giovanni E; Pjetursson, Bjarni; Brägger, Urs
2009-07-01
To assess retrospectively the cumulative costs for the long-term oral rehabilitation of patients with birth defects affecting the development of teeth. Patients with birth defects who had received fixed reconstructions on teeth and/or implants > or =5 years ago were asked to participate in a comprehensive clinical, radiographic and economic evaluation. From the 45 patients included, 18 were cases with a cleft lip and palate, five had amelogenesis/dentinogenesis imperfecta and 22 were cases with hypodontia/oligodontia. The initial costs for the first oral rehabilitation (before the age of 20) had been covered by the Swiss Insurance for Disability. The costs for the initial rehabilitation of the 45 cases amounted to 407,584 CHF (39% for laboratory fees). Linear regression analyses for the initial treatment costs per replaced tooth revealed the formula 731 CHF+(811 CHF x units) on teeth and 3369 CHF+(1183 CHF x units) for reconstructions on implants (P<.001). Fifty-eight percent of the patients with tooth-supported reconstructions remained free from failures/complications (median observation 15.7 years). Forty-seven percent of the patients with implant-supported reconstructions remained free from failures/complications (median observation 8 years). The long-term cumulative treatment costs for implant cases, however, were not statistically significantly different compared with cases reconstructed with tooth-supported fixed reconstructions. Twenty-seven percent of the initial treatment costs were needed to cover supportive periodontal therapy as well as the treatment of technical/biological complications and failures. Insurance companies should accept to cover implant-supported reconstructions because there is no need to prepare healthy teeth, fewer tooth units need to be replaced and the cumulative long-term costs seem to be similar compared with cases restored on teeth.
Ma, Tongliang; Zhu, Decai; Chen, Duoxue; Zhang, Qiaoyun; Dong, Huifang; Wu, Wenwu; Lu, Huihe; Wu, Guangfu
2018-03-12
BACKGROUND The aim of this study was to investigate the effects of sulforaphane (SFN), a natural isothiocyanate compound, in a rabbit ascending aortic cerclage model of chronic heart failure (CHF). MATERIAL AND METHODS Thirty New Zealand White rabbits were divided into the sham operation group (n=10), the CHF group (n=10), and the CHF + SFN group (n=10) treated with subcutaneous SFN (0.5 mg/kg) for five days per week for 12 weeks. After 12 weeks, echocardiography and biometric analysis were performed, followed by the examination of the rabbit hearts. Enzyme-linked immunosorbent assay (ELISA) and Western blot were used to detect levels of inflammatory cytokines, superoxide dismutase (SOD), and malondialdehyde (MDA). RESULTS In the CHF group, compared with the sham operation group, there was an increase in the heart weight to body weight ratio (HW/BW), the left ventricular weight to body weight ratio (LVW/BW), the left ventricular end diastolic diameter (LVEDD), the left ventricular end systolic diameter (LVESD), plasma brain natriuretic peptide (BNP) and atrial natriuretic peptide (ANP) levels, the cardiac collagen volume fraction (CVF), apoptotic index, expression levels of collagen I, collagen III, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and malondialdehyde (MDA) in the myocardial tissue, and a decrease in the left ventricular shortening fraction (LVFS) and left ventricular ejection fraction (LVEF), and cardiac superoxide dismutase (SOD) activity. These changes were corrected in the SFN-treated group. CONCLUSIONS In a rabbit model of CHF, treatment with SFN improved cardiac function and remodeling by inhibiting oxidative stress and inflammation.
NADPH oxidase contributes to coronary endothelial dysfunction in the failing heart.
Zhang, Ping; Hou, Mingxiao; Li, Yunfang; Xu, Xin; Barsoum, Michel; Chen, Yingjie; Bache, Robert J
2009-03-01
Increased reactive oxygen species (ROS) produced by the failing heart can react with nitric oxide (NO), thereby decreasing NO bioavailability. This study tested the hypothesis that increased ROS generation contributes to coronary endothelial dysfunction in the failing heart. Congestive heart failure (CHF) was produced in six dogs by ventricular pacing at 240 beats/min for 4 wk. Studies were performed at rest and during treadmill exercise under control conditions and after treatment with the NADPH oxidase inhibitor and antioxidant apocynin (4 mg/kg iv). Apocynin caused no significant changes in heart rate, aortic pressure, left ventricular (LV) systolic pressure, LV end-diastolic pressure, or maximum rate of LV pressure increase at rest or during exercise in normal or CHF dogs. Apocynin caused no change in coronary blood flow (CBF) in normal dogs but increased CBF at rest and during exercise in animals with CHF (P < 0.05). Intracoronary ACh caused dose-dependent increases of CBF that were blunted in CHF. Apocynin had no effect on the response to ACh in normal dogs but augmented the response to ACh in CHF dogs (P < 0.05). The oxidative stress markers nitrotyrosine and 4-hydroxy-2-nonenal were significantly greater in failing than in normal myocardium. Furthermore, coelenterazine chemiluminescence for O(2)(-) was more than twice normal in failing myocardium, and this difference was abolished by apocynin. Western blot analysis of myocardial lysates demonstrated that the p47(phox) and p22(phox) subunits of NADPH were significantly increased in the failing hearts, while real-time PCR demonstrated that Nox2 mRNA was significantly increased. The data indicate that increased ROS generation in the failing heart is associated with coronary endothelial dysfunction and suggest that NADPH oxidase may contribute to this abnormality.
NASA Technical Reports Server (NTRS)
McElmurray, J. H. 3rd; Mukherjee, R.; New, R. B.; Sampson, A. C.; King, M. K.; Hendrick, J. W.; Goldberg, A.; Peterson, T. J.; Hallak, H.; Zile, M. R.;
1999-01-01
The progression of congestive heart failure (CHF) is left ventricular (LV) myocardial remodeling. The matrix metalloproteinases (MMPs) contribute to tissue remodeling and therefore MMP inhibition may serve as a useful therapeutic target in CHF. Angiotensin converting enzyme (ACE) inhibition favorably affects LV myocardial remodeling in CHF. This study examined the effects of specific MMP inhibition, ACE inhibition, and combined treatment on LV systolic and diastolic function in a model of CHF. Pigs were randomly assigned to five groups: 1) rapid atrial pacing (240 beats/min) for 3 weeks (n = 8); 2) ACE inhibition (fosinopril, 2.5 mg/kg b.i.d. orally) and rapid pacing (n = 8); 3) MMP inhibition (PD166793 2 mg/kg/day p.o.) and rapid pacing (n = 8); 4) combined ACE and MMP inhibition (2.5 mg/kg b.i.d. and 2 mg/kg/day, respectively) and rapid pacing (n = 8); and 5) controls (n = 9). LV peak wall stress increased by 2-fold with rapid pacing and was reduced in all treatment groups. LV fractional shortening fell by nearly 2-fold with rapid pacing and increased in all treatment groups. The circumferential fiber shortening-systolic stress relation was reduced with rapid pacing and increased in the ACE inhibition and combination groups. LV myocardial stiffness constant was unchanged in the rapid pacing group, increased nearly 2-fold in the MMP inhibition group, and was normalized in the ACE inhibition and combination treatment groups. Increased MMP activation contributes to the LV dilation and increased wall stress with pacing CHF and a contributory downstream mechanism of ACE inhibition is an effect on MMP activity.
Harada, Daisuke; Aasanoi, Hidetsugu; Ushijima, Ryuichi; Noto, Takahisa; Takagawa, Junya; Ishise, Hisanari; Inoue, Hiroshi
2018-06-01
To elucidate involvement of age-related impairments of right ventricular (RV) distensibility in the elderly congestive heart failure (CHF), we examined the prevalence of less-distensible right ventricle in patients with preserved left ventricular ejection fraction (LVEF) over a wide range of ages. In 893 patients aged from 40 to 102 years, we simultaneously recorded electrocardiogram, phonocardiogram, and jugular venous pulse wave. Using signal-processing techniques, the prominent 'Y' descent of jugular pulse waveform was detected as a hemodynamic sign of a less-distensible right ventricle. Prevalence of less-distensible right ventricle and elevated RV systolic pressure increased along with aging from the 50s to the 90s in an exponential fashion from 3.3 and 12% up to 33 and 61%, respectively (p < 0.001 for each). This age-dependent deterioration of ventricular distensibility was not observed for the left ventricle. Higher age and higher RV systolic pressure were independently associated with less-distensible right ventricle (Odds ratio, 1.05 per 1 year, p = 0.003; and 1.03 per 1 mmHg, p = 0.026, respectively). The elderly CHF was associated with high prevalence of the less-distensible right ventricle and higher RV systolic pressure, both of which were independent risk factors for CHF (Odds ratio, 5.27, p = 0.001, and 1.08 per 1 mmHg, p < 0.001, respectively). In elderly patients with preserved LVEF, the combination of a less-distensible right ventricle and a high RV systolic pressure seems to be related to developing CHF. The less-distensible right ventricle and elevated RV systolic pressure are closely associated with CHF with preserved LVEF in the elderly patients.
Parisot, Juliette; Damy, Thibaud; Gellen, Barnabas; Covali-Noroc, Ala; Bodez, Diane; Rappeneau, Stéphane; Guellich, Aziz; Adnot, Serge; Bastuji-Garin, Sylvie; Hittinger, Luc; d'Ortho, Maria-Pia; Boyer, Laurent; Canouï-Poitrine, Florence
2015-09-01
Sleep-disordered breathing (SDB) is highly prevalent and of adverse prognostic significance in patients with chronic heart failure (CHF). Polygraphy is used for diagnosing SDB but polygraphy resources fall short of needs. Here, our aim was to develop a score for SDB screening in patients with CHF. Consecutive patients with stable chronic CHF referred to our CHF clinic for a scheduled follow-up evaluation were included prospectively between 2000 and 2012. SDB was defined as an apnoea-hypopnoea index ≥ 5/h as assessed by routine polygraphy. A screening score was developed as a linear combination of factors independently associated with SDB by multivariate logistic regression. Calibration and discrimination were evaluated using the Hosmer-Lemeshow (HL) test and area under the receiver-operating characteristics curve (AUC), respectively. Bootstrapping was performed to assess internal validity. Of 450 included patients (mean age, 59.5 ± 13.7 years), 397 (88%) had SDB. An easy-to-use score was based on age (2 points if ≥65 years), body mass index (2 points if ≥25 kg/m(2)), New York Heart Association (NYHA) class (2 points if ≥3 or 4) and male gender (3 points). A score cut-off of 5 was 78.9% sensitive and 61.5% specific for SDB. The final model exhibited adequate calibration (pHL ≥ 0.3) and discrimination (AUC, 0.737; 95% confidence interval, 0.663; 0.810). An easy-to-use clinical score combining age, body mass index, NYHA class, and gender may help to identify those CHF patients most likely to have SDB, thereby improving the allocation of scarce polygraphy resources and early diagnosis of SDB. Copyright © 2014 Elsevier B.V. All rights reserved.
Juneman, Elizabeth B; Saleh, Laith; Lancaster, Jordan J; Thai, Hoang M; Markham, Bruce; Goldman, Steven
2012-09-01
Poloxamer-188 (P-188) is a biological membrane sealant that prevents the unregulated entry of Ca into cardiomyocytes and has been shown to have the ability to act as a membrane-repair agent in isolated cardiac myocytes. The purpose of this study was to determine if treatment with P-188 would improve left ventricular (LV) function in a rat chronic heart failure (CHF) model. We ligated the left coronary artery of adult male Sprague-Dawley rats to induce a myocardial infarction (MI). The rats were allowed to recover for 8 weeks until stable CHF was present and treated with a range of P-188 doses [1.5 mg/kg (N = 6), 4.6 mg/kg (N = 11), 15.3 mg/kg (N = 11), and 460 mg/kg (N = 6)] delivered via 30 minutes of intravenous infusion. The rats were randomized to study groups: control, 2 hours, 24 hours, 48 hours, 1 week, and 2 weeks posttreatment (N = 8 in each group). Two weeks after high dose (460 mg/kg) administration, P-188 improved (P < 0.05) left ventricular ejection fraction from 34% to 51%, which persisted over 38 hours and decreased (P < 0.05) LV end systolic diameter from 0.9 ± 0.07 to 0.6 ± 0.08 cm, in the rats with CHF. There was no statistical change in hemodynamics. Additionally, P-188 reduced (P < 0.05) circulating troponin levels 2 weeks after treatment. Treatment with P-188 improves the LV function and partially reverses maladaptive LV remodeling in rats with moderate CHF after MI. These data introduce the idea of using a biological membrane sealant as a new approach to treating CHF after MI.
Influence of aging and chronic heart failure on temporal dispersion of myocardial repolarization
Piccirillo, Gianfranco; Moscucci, Federica; Pascucci, Matteo; Pappadà, Maria Antonella; D’Alessandro, Gaetana; Rossi, Pietro; Quaglione, Raffaele; Di Barba, Daniele; Barillà, Francesco; Magrì, Damiano
2013-01-01
Background and purpose: QT and Tpeak-Tend (Te) intervals are associated with sudden cardiac death in patients with chronic heart failure (CHF). We studied age-dependent influence on short-term temporal dispersion of these two variables in patients with postischemic CHF. Method: We grouped 75 CHF and 53 healthy control subjects into three age subsets: ≤50 years, >50 years and ≤65 years, and >65 years. We then calculated the following indices: QT and Te variability index (QTVI and TeVI), the ratio between the short-term variability (STV) of QT or Te, and the STV of resting rate (RR) (QT/RR STV and Te/RR STV). Results: In all different age subgroups, patients with CHF showed a higher level of QTVI than age-matched control subjects (≤50 years: P < 0.0001; >50 years and ≤65 years: P < 0.05; >65 years: P < 0.05). Patients with CHF < 50 years old also had all repolarization variability indices higher than normal age-matched controls (TeVI, P < 0.05; QT/RR STV, P < 0.05; Te/RR STV, P < 0.05), whereas we did not find any difference between the two older classes of subjects. Both QTVI (r2: 0.178, P < 0.05) and TeVI (r2: 0.433, P < 0.001) were positively related to age in normal subjects, even if the first correlation was weaker than the second one. Conclusion: Our data showed that QTVI could be used in all ages to evaluate repolarization temporal liability, whereas the other indices are deeply influenced by age. Probably, the age-dependent increase in QTVI was more influenced by a reduction of RR variability reported in older normal subjects. PMID:23662051
Influence of aging and chronic heart failure on temporal dispersion of myocardial repolarization.
Piccirillo, Gianfranco; Moscucci, Federica; Pascucci, Matteo; Pappadà, Maria Antonella; D'Alessandro, Gaetana; Rossi, Pietro; Quaglione, Raffaele; Di Barba, Daniele; Barillà, Francesco; Magrì, Damiano
2013-01-01
QT and T(peak)-T(end) (Te) intervals are associated with sudden cardiac death in patients with chronic heart failure (CHF). We studied age-dependent influence on short-term temporal dispersion of these two variables in patients with postischemic CHF. We grouped 75 CHF and 53 healthy control subjects into three age subsets: ≤ 50 years, >50 years and ≤ 65 years, and >65 years. We then calculated the following indices: QT and Te variability index (QTVI and TeVI), the ratio between the short-term variability (STV) of QT or Te, and the STV of resting rate (RR) (QT/RR STV and Te/RR STV). In all different age subgroups, patients with CHF showed a higher level of QTVI than age-matched control subjects (≤ 50 years: P < 0.0001; >50 years and ≤ 65 years: P < 0.05; >65 years: P < 0.05). Patients with CHF < 50 years old also had all repolarization variability indices higher than normal age-matched controls (TeVI, P < 0.05; QT/RR STV, P < 0.05; Te/RR STV, P < 0.05), whereas we did not find any difference between the two older classes of subjects. Both QTVI (r²: 0.178, P < 0.05) and TeVI (r²: 0.433, P < 0.001) were positively related to age in normal subjects, even if the first correlation was weaker than the second one. Our data showed that QTVI could be used in all ages to evaluate repolarization temporal liability, whereas the other indices are deeply influenced by age. Probably, the age-dependent increase in QTVI was more influenced by a reduction of RR variability reported in older normal subjects.
NASA Astrophysics Data System (ADS)
Fukuda, Hiroki; Suwa, Hideaki; Nakano, Atsushi; Sakamoto, Mari; Imazu, Miki; Hasegawa, Takuya; Takahama, Hiroyuki; Amaki, Makoto; Kanzaki, Hideaki; Anzai, Toshihisa; Mochizuki, Naoki; Ishii, Akira; Asanuma, Hiroshi; Asakura, Masanori; Washio, Takashi; Kitakaze, Masafumi
2016-11-01
Brain natriuretic peptide (BNP) is the most effective predictor of outcomes in chronic heart failure (CHF). This study sought to determine the qualitative relationship between the BNP levels at discharge and on the day of cardiovascular events in CHF patients. We devised a mathematical probabilistic model between the BNP levels at discharge (y) and on the day (t) of cardiovascular events after discharge for 113 CHF patients (Protocol I). We then prospectively evaluated this model on another set of 60 CHF patients who were readmitted (Protocol II). P(t|y) was the probability of cardiovascular events occurring after >t, the probability on t was given as p(t|y) = -dP(t|y)/dt, and p(t|y) = pP(t|y) = αyβP(t|y), along with p = αyβ (α and β were constant); the solution was p(t|y) = αyβ exp(-αyβt). We fitted this equation to the data set of Protocol I using the maximum likelihood principle, and we obtained the model p(t|y) = 0.000485y0.24788 exp(-0.000485y0.24788t). The cardiovascular event-free rate was computed as P(t) = 1/60Σi=1,…,60 exp(-0.000485yi0.24788t), based on this model and the BNP levels yi in a data set of Protocol II. We confirmed no difference between this model-based result and the actual event-free rate. In conclusion, the BNP levels showed a non-linear relationship with the day of occurrence of cardiovascular events in CHF patients.
Dai, Yuxiang; Yang, Jun; Takagi, Atsutoshi; Konishi, Hakuoh; Miyazaki, Tetsuro; Masuda, Hiroshi; Shimada, Kazunori; Miyauchi, Katsumi; Daida, Hiroyuki
2017-08-01
Relative changes in B-type natriuretic peptide (BNP) and amino terminal pro-BNP (NT-proBNP) levels may help to assess the risk of congestive heart failure (CHF). However, whether these levels at the time of admission enable the prediction of outcomes with acute exacerbation remains unknown. The current study determined the abilities of BNP, NT-proBNP and their ratio to predict in-hospital and long-term outcomes of patients with CHF. Patients who were admitted to the cardiac care unit of Juntendo University Hospital (Tokyo, Japan) with acute CHF onset were consecutively enrolled into the present observational study. Serum levels of BNP and NT-proBNP were immediately measured on admission, and other biomarkers and clinical data were also investigated. Of 195 enrolled patients, 16 (8.2%) succumbed to CHF in hospital and 124 (69.3%) reached the endpoint of mortality or readmission following a median follow-up of 14 months. Multiple linear regression analysis revealed body mass index, low density lipoprotein cholesterol, hemoglobin, estimated glomerular filtration rate and C-reactive protein as independent predictors of the NT-proBNP/BNP ratio. BNP, NT-proBNP and their ratio were significantly higher among those who succumbed to CHF than in those who remained alive in hospital (P<0.05). Logistic regression analysis indicated that the ratio was an independent predictor for in-hospital mortality and long-term outcomes. In conclusion, the ratio of NT-proBNP to BNP more effectively predicts in-hospital outcomes than either factor alone and it may also help to predict outcomes among patients with acute exacerbation of HF.
Effect of coenzyme Q10 supplementation on heart failure: a meta-analysis123
Thompson-Paul, Angela M; Bazzano, Lydia A
2013-01-01
Background: Coenzyme Q10 (CoQ10; also called ubiquinone) is an antioxidant that has been postulated to improve functional status in congestive heart failure (CHF). Several randomized controlled trials have examined the effects of CoQ10 on CHF with inconclusive results. Objective: The objective of this meta-analysis was to evaluate the impact of CoQ10 supplementation on the ejection fraction (EF) and New York Heart Association (NYHA) functional classification in patients with CHF. Design: A systematic review of the literature was conducted by using databases including MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, and manual examination of references from selected studies. Studies included were randomized controlled trials of CoQ10 supplementation that reported the EF or NYHA functional class as a primary outcome. Information on participant characteristics, trial design and duration, treatment, dose, control, EF, and NYHA classification were extracted by using a standardized protocol. Results: Supplementation with CoQ10 resulted in a pooled mean net change of 3.67% (95% CI: 1.60%, 5.74%) in the EF and −0.30 (95% CI: −0.66, 0.06) in the NYHA functional class. Subgroup analyses showed significant improvement in EF for crossover trials, trials with treatment duration ≤12 wk in length, studies published before 1994, and studies with a dose ≤100 mg CoQ10/d and in patients with less severe CHF. These subgroup analyses should be interpreted cautiously because of the small number of studies and patients included in each subgroup. Conclusions: Pooled analyses of available randomized controlled trials suggest that CoQ10 may improve the EF in patients with CHF. Additional well-designed studies that include more diverse populations are needed. PMID:23221577
Adaptive servo-ventilation therapy of central sleep apnoea and its effect on sleep quality.
Hetzenecker, Andrea; Roth, Tatjana; Birner, Christoph; Maier, Lars S; Pfeifer, Michael; Arzt, Michael
2016-03-01
Poor sleep quality is common in patients with chronic heart failure (CHF). This study tested the hypothesis that adaptive servo-ventilation (ASV) therapy in CHF patients whose central sleep apnoea (CSA) was not suppressed by continuous positive airway pressure (CPAP) (CPAP-non-responders) would improve sleep quality compared to CPAP-responders receiving ongoing CPAP therapy. Eighty-two patients with CHF (65 ± 9 years, left ventricular ejection fraction 35 ± 16 %) and CSA [apnoea-hypopnoea index (AHI) ≥15/h] were retrospectively studied. Within an average of 47 days, patients were reevaluated on CPAP therapy and stratified according to their suppression of CSA: 34 were CPAP-non-responders switched to ASV therapy the following day and 48 were CPAP-responders who continued on CPAP therapy. Polysomnographic parameters were assessed in the diagnostic night and on the last night of PAP therapy (CPAP or ASV) before the patient was discharged with the final pressure settings. Compared with the CPAP group, the ASV group had significantly greater reductions from baseline in AHI (-37 ± 15/h vs -28 ± 18/h, p = 0.02), arousal index (-12.7 ± 13.6/h vs -6.8 ± 12.5/h, p = 0.04) and sleep stage N1 (-9 ± 14 % vs -2 ± 12 %, p = 0.03). In addition, the ASV group gained significantly more rapid eye movement (REM) sleep compared with the CPAP group (+5 ± 9 % vs +1 ± 9 %, p = 0.02). CPAP therapy is effective in reducing AHI in a significant proportion of CHF patients with reduced ejection fraction and CSA. Treatment of CSA with ASV in CHF patients reduces sleep fragmentation and improves sleep structure to a significantly greater extent than changes seen in responders to CPAP therapy.
Cygankiewicz, Iwona; Zareba, Wojciech; Vazquez, Rafael; Vallverdu, Montserrat; Gonzalez-Juanatey, Jose R; Valdes, Mariano; Almendral, Jesus; Cinca, Juan; Caminal, Pere; de Luna, Antoni Bayes
2008-08-01
Abnormal heart rate turbulence (HRT) has been documented as a strong predictor of total mortality and sudden death in postinfarction patients, but data in patients with congestive heart failure (CHF) are limited. The aim of this study was to evaluate the prognostic significance of HRT for predicting mortality in CHF patients in New York Heart Association (NYHA) class II-III. In 651 CHF patients with sinus rhythm enrolled into the MUSIC (Muerte Subita en Insuficiencia Cardiaca) study, the standard HRT parameters turbulence onset (TO) and slope (TS), as well as HRT categories, were assessed for predicting total mortality and sudden death. HRT was analyzable in 607 patients, mean age 63 years (434 male), 50% of ischemic etiology. During a median follow up of 44 months, 129 patients died, 52 from sudden death. Abnormal TS and HRT category 2 (HRT2) were independently associated with increased all-cause mortality (HR: 2.10, CI: 1.41 to 3.12, P <.001 and HR: 2.52, CI: 1.56 to 4.05, P <.001; respectively), sudden death (HR: 2.25, CI: 1.13 to 4.46, P = .021 for HRT2), and death due to heart failure progression (HR: 4.11, CI: 1.84 to 9.19, P <.001 for HRT2) after adjustment for clinical covariates in multivariate analysis. The prognostic value of TS for predicting total mortality was similar in various groups dichotomized by age, gender, NYHA class, left ventricular ejection fraction, and CHF etiology. TS was found to be predictive for total mortality only in patients with QRS > 120 ms. HRT is a potent risk predictor for both heart failure and arrhythmic death in patients with class II and III CHF.
Thomas, George; Xie, Dawei; Chen, Hsiang-Yu; Anderson, Amanda H.; Appel, Lawrence; Bodana, Shirisha; Brecklin, Carolyn S.; Drawz, Paul; Flack, John M.; Miller, Edgar R.; Steigerwalt, Susan P.; Townsend, Raymond R.; Weir, Matthew R.; Wright, Jackson T.; Rahman, Mahboob
2015-01-01
The association between apparent treatment resistant hypertension (ATRH) and clinical outcomes is not well studied in chronic kidney disease (CKD). We analyzed data on 3367 hypertensive participants in the Chronic Renal Insufficiency Cohort (CRIC) to determine prevalence, associations, and clinical outcomes of ATRH in non-dialysis CKD patients. ATRH was defined as blood pressure (BP) ≥140/90 mm Hg on ≥3 antihypertensives, or use of ≥4 antihypertensives with BP at goal at baseline visit. Prevalence of ATRH was 40.4%. Older age, male gender, black race, diabetes, and higher BMI were independently associated with higher odds of having ATRH. Participants with ATRH had a higher risk of clinical events compared to participants without ATRH - composite of myocardial infarction (MI), stroke, peripheral arterial disease (PAD), congestive heart failure (CHF), and all-cause mortality HR [95% CI]: (1.38 [1.22,1.56]); renal events (1.28 [1.11, 1.46]); CHF (1.66 [1.38, 2.00]); and all-cause mortality (1.24 [1.06,1.45]). The subset of participants with ATRH and BP at goal on ≥ 4 medications also had higher risk for composite of MI, stroke, PAD, CHF, and all-cause mortality HR [95% CI] (1.30 [1.12, 1.51]) and CHF (1.59 [1.28, 1.99]) compared to those without ATRH. ATRH was associated with significantly higher risk for CHF and renal events only among those with eGFR ≥30 ml/min/1.73 m2. Our findings show that ATRH is common and associated with high risk of adverse outcomes in a cohort of patients with CKD. This underscores the need for early identification and management of patients with ATRH and CKD. PMID:26711738
Jeger, Raban V; Pfister, Otmar; Radovanovic, Dragana; Eberli, Franz R; Rickli, Hans; Urban, Philip; Pedrazzini, Giovanni; Stauffer, Jean-Christophe; Nossen, Jörg; Erne, Paul
2017-10-01
Data on temporal trends of heart failure (HF) in acute coronary syndrome (ACS) are scarce. Improved treatment options may have led to lower case-fatality rates (CFRs) during the last years in ACS complicated by HF. Patients of the nationwide Acute Myocardial Infarction in Switzerland (AMIS)-Plus ACS registry were analyzed from 2000 to 2014. Of 36 366 ACS patients, 3376 (9.3%) had acute or chronic HF, 2111 (5.8%) de novo acute HF (AHF), 964 (2.7%) chronic HF (CHF), and 301 (0.8%) acute decompensated CHF (ADCHF). In-hospital CFRs were highest in patients with ADCHF (32.6%) and de novo AHF (29.7%), followed by patients with CHF (12.9%) and without HF (3.2%, P < 0.001). Although in-hospital CFRs gradually decreased in CHF patients (14.3% to 4.5%, P = 0.003) and patients without HF (3.5% to 2.2%, P < 0.001), they remained high in patients with ADCHF (36.4% to 40.0%, P = 0.45) and de novo AHF (50.0% to 29.4%, P = 0.37). Although there was an increase in specific ACS therapies in the cohort over time, ACS patients with HF received significantly less pharmacological and interventional ACS therapies than patients without HF. There was no significant change in HF medication rates except less frequent use of β-blockers and diuretics in de novo AHF patients in recent years. HF is present in 1 out of 10 patients presenting with ACS and is associated with high in-hospital CFRs, particularly in acute HF. Although advances in ACS therapy improved in-hospital CFRs in patients with no HF or CHF, CFRs remained unchanged and high in patients with acute HF and ACS over the last decade. © 2017 Wiley Periodicals, Inc.
Schou, Morten; Gustafsson, Finn; Videbaek, Lars; Markenvard, John; Ulriksen, Hans; Ryde, Henrik; Jensen, Jens C H; Nielsen, Tonny; Knudsen, Anne S; Tuxen, Christian D; Handberg, Jens; Sørensen, Per J; Espersen, Geert; Lind-Rasmussen, Søren; Keller, Niels; Egstrup, Kenneth; Nielsen, Olav W; Abdulla, Jawdat; Nyvad, Ole; Toft, Jens; Hildebrandt, Per R
2008-10-01
Randomized clinical trials have shown that newly discharged and symptomatic patients with chronic heart failure (CHF) benefit from follow-up in a specialized heart failure clinic (HFC). Clinical stable and educated patients are usually discharged from the HFC when on optimal therapy. It is unknown if risk stratification using natriuretic peptides could identify patients who would benefit from longer-term follow-up. Furthermore, data on the use of natriuretic peptides for monitoring of stable patients with CHF are sparse. The aims of this study are to test the hypothesis that clinical stable, educated, and medical optimized patients with CHF with N-terminal pro-brain natriuretic peptide (NT-proBNP) levels > or = 1,000 pg/mL benefit from long-term follow-up in an HFC and to assess the efficacy of NT-proBNP monitoring. A total of 1,250 clinically stable, medically optimized, and educated patients with CHF will be enrolled from 18 HFCs in Denmark. The patients will be randomized to treatment in general practice, to a standard follow-up program in the HFC, or to NT-proBNP monitoring in the HFC. The patients will be followed for 30 months (median). Data will be collected from 2006 to 2009. At present (March 2008), 720 patients are randomized. Results expect to be presented in the second half of 2010. This article outlines the design of the NorthStar study. If our hypotheses are confirmed, the results will help cardiologists and nurses in HFCs to identify patients who may benefit from long-term follow-up. Our results may also indicate whether patients with CHF will benefit from adding serial NT-proBNP measurements to usual clinical monitoring.
Yamauchi, S; Takeishi, Y; Minamihaba, O; Arimoto, T; Hirono, O; Takahashi, H; Miyamoto, T; Nitobe, J; Nozaki, N; Tachibana, H; Watanabe, T; Fukui, A; Kubota, I
2003-08-01
This study aimed to examine whether angiotensin-converting enzyme (ACE) inhibition improved cardiac fatty acid metabolism in patients with congestive heart failure (CHF). Myocardial 123I-beta-methyl-iodophenylpentadecanoic acid (123I-BMIPP) imaging was performed in 25 patients with CHF and in 10 control subjects. Myocardial 123I-BMIPP images were obtained 30 min and 4 h after tracer injection. The heart-to-mediastinum (H/M) ratio of 123I-BMIPP uptake and the washout rate of 123I-BMIPP from the myocardium were calculated. Patients were given enalapril for 6 months, and 123I-BMIPP imaging was repeated. H/M ratios on early and delayed images were lower in CHF patients than in normal controls (P<0.01). The washout rate of 123I-BMIPP from the myocardium was faster in CHF patients than in controls (P<0.01). As the severity of the New York Heart Association (NYHA) functional class increased, the H/M ratio decreased and the washout rate increased. The washout rate of 123I-BMIPP was inversely correlated with left ventricular fractional shortening (R=-0.62, P<0.01). ACE inhibition with enalapril increased the H/M ratio on delayed images (P<0.05) and reduced the washout rate of 123I-BMIPP (P<0.05) in CHF patients. These data suggest that: (1) angiotensin II-mediated intracellular signalling activation may be a possible mechanism for the decreased myocardial uptake and enhanced washout of 123I-BMIPP in heart failure patients; and (2) the improvement in fatty acid metabolism by ACE inhibition may represent a new mechanism for the beneficial effect of this therapy in heart failure.
Andrews, D; Gouda, M S; Higgins, S; Johnson, P; Williams, A; Vandenburg, M
2002-01-01
Congestive heart failure (CHF) is a major and increasing chronic disease in Western society, with a high mortality, morbidity and cost for unplanned hospital admissions. Continuous cardiorespiratory monitoring is required to detect Cheyne-Stokes respiration (CSR). We have tested a new wireless monitoring system and compared it with polysomnography (PSG) and respiratory inductance plethysmography (RIP) in six CHF patients with CSR in a sleep laboratory. The wireless system compared well with RIP for the detection of CSR but less well with PSG, which had unexpected but significant respiratory sensing errors that led to misclassification of the respiratory disorder present. The wireless system could be used to select CHF patients for better-customized treatment at home as part of a specialist-supported community telemedicine programme.
Iacoviello, Massimo; Leone, Marta; Antoncecchi, Valeria; Ciccone, Marco Matteo
2015-01-01
Chronic kidney disease and its worsening are recurring conditions in chronic heart failure (CHF) which are independently associated with poor patient outcome. The heart and kidney share many pathophysiological mechanisms which can determine dysfunction in each organ. Cardiorenal syndrome is the condition in which these two organs negatively affect each other, therefore an accurate evaluation of renal function in the clinical setting of CHF is essential. This review aims to revise the parameters currently used to evaluate renal dysfunction in CHF with particular reference to the usefulness and the limitations of biomarkers in evaluating glomerular dysfunction and tubular damage. Moreover, it is reported the possible utility of renal arterial resistance index (a parameter associated with abnormalities in renal vascular bed) for a better assesment of kidney disfunction. PMID:25610846
Gergei, Ingrid; Krämer, Bernhard K; Scharnagl, Hubert; Stojakovic, Tatjana; März, Winfried; Mondorf, Ulrich
The endothelin system (Big-ET-1) is a key regulator in cardiovascular (CV) disease and congestive heart failure (CHF). We have examined the incremental value of Big-ET-1 in predicting total and CV mortality next to the well-established CV risk marker N-Terminal Pro-B-Type Natriuretic Peptide (NT-proBNP). Big-ET-1 and NT-proBNP were determined in 2829 participants referred for coronary angiography (follow-up 9.9 years). Big-ET-1 is an independent predictor of total, CV mortality and death due to CHF. The conjunct use of Big-ET-1 and NT-proBNP improves the risk stratification of patients with intermediate to high risk of CV death and CHF. Big-ET-1improves risk stratification in patients referred for coronary angiography.
NASA Technical Reports Server (NTRS)
Atkinson, Roger
1990-01-01
In the present assessment, the hydrogen containing halocarbons being considered as alternatives to the the presently used chlorofluorocarbons are the hydrochlorofluorocarbons (HCFCs) 123 (CF3CHCl2), 141b (CFCl2CH3), 142b (CF2ClCH3), 22 (CHF2Cl) and 124 (CF3CHFCl) and the hydrofluorocarbons (HFCs) 134a (CF3CH2F), 152a (CHF2CH3) and 125 (CF3CHF2). All of these HCFCs and HFCs will react with the hydroxyl (OH) radical in the troposphere, giving rise to haloalkyl radicals which then undergo a complex series of reactions in the troposphere. These reactions of the haloalkyl radicals formed from the initial OH radical reactions with the HCFCs and HFCs under tropospheric conditions are the focus here.
Atmospheric Lifetime of CHF2Br, a Proposed Substitute for Halons.
Talukdar, R; Mellouki, A; Gierczak, T; Burkholder, J B; McKeen, S A; Ravishankara, A R
1991-05-03
The rate coefficients, k(1), for the reaction of OH with CHF(2)Br have been measured using pulsed photolysis and discharge flow techniques at temperatures (T) between 233 and 432 K to be k(1), = (7.4 +/- 1.6) x 10(-13) exp[-(1300 +/- 100)/T] cubic centimeters per molecule per second. The ultraviolet absorption cross sections, sigma, of this molecule between 190 and 280 nanometers were measured at 296 K. The k(1), and sigma values were used in a one-dimensional model to obtain an atmospheric lifetime of approximately 7 years for CHF(2)Br. This lifetime is shorter by approximately factors of 10 and 2 than those for CF(3)Br and CF(2)ClBr, respectively. The ozone depletion potentials of the three compounds will reflect these lifetimes.
Contextualizing Genetics for Regional Heart Failure Care
Iyngkaran, Pupalan; Thomas, Merlin C.; Johnson, Renee; French, John; Ilton, Marcus; McDonald, Peter; Hare, David L.; Fatkin, Diane
2016-01-01
Congestive heart failure (CHF) is a chronic and often devastating cardiovascular disorder with no cure. There has been much advancement in the last two decades that has seen improvements in morbidity and mortality. Clinicians have also noted variations in the responses to therapies. More detailed observations also point to clusters of diseases, phenotypic groupings, unusual severity and the rates at which CHF occurs. Medical genetics is playing an increasingly important role in answering some of these observations. This developing field in many respects provides more information than is currently clinically applicable. This includes making sense of the established single gene mutations or uncommon private mutations. In this thematic series which discusses the many factors that could be relevant for CHF care, once established treatments are available in the communities; this section addresses a contextual role for medical genetics. PMID:27280306
Carotid body: a new target for rescuing neural control of cardiorespiratory balance in disease.
Fitzgerald, Robert S
2014-01-01
Significant insight into the mechanisms involved in chronic heart failure (CHF) have been provided by Schultz and his associates at the University of Nebraska Medical Center with the use of pacing-induced heart failure rabbits. Critical among the CHF mechanisms was the role of the carotid body (CB). The stimulated CB produces a wide array of systemic reflex responses; certainly those in the cardiopulmonary (CP) system are the most important in CHF. This generates a question as to whether the CB could serve as a target for some kind of treatment to reestablish control of cardiorespiratory balance in CHF. Any treatment would have to be based on a solid understanding of the mechanisms of chemosensing by the CB as well as the transducing of that sensing into neural activity sent to the medullary centers and regions of autonomic outflow to the periphery. Two avenues of treatment could be to (1) silence or attenuate the CB's neural output pharmacologically and (2) excise the CBS. There is a long history of CB removal mostly as a remedy for chronic obstructive lung disease. Results have been inconclusive as to the effectiveness of this procedure. But if carefully planned, the procedure might be a helpful treatment.
Artists Make the Invisible VIsible
NASA Astrophysics Data System (ADS)
Burko, D.
2013-12-01
As artists cross academic boundaries with increasing frequency to investigate, observe, and translate our environment and its complex processes - scientific institutions and museums are bringing this new activity to the attention of the public. The Chemical Heritage Foundation (CHF) is one organization pioneering this effort with its yearlong art exhibition Sensing Change featuring eight nationally recognized artists. CHF is using the exhibition as a framework within which to question the artists' motivations for creating works dedicated to local and global environmental change. They also explore the tools each artists uses and the artists' efforts to engage the public. In addition to the exhibition, CHF is scheduling "related programming and scholarship that explore daily shifts in our environment and long-term climate change; the visualization of data and largely invisible natural processes; and the potential role of art in science communication.' To that end they have developed an interactive web site that features the following: 1) video interviews with each of the eight artists 2) oral histories from a broad selection of atmospheric scientists on our ever evolving understanding of air 3) histories of the scientific instruments in the CHF collection that measure environmental and atmospheric data My presentation will review these elements and serve as a template to hopefully inspire the adaptation of this model by other scientific and educational bodies.
Hartmann, Franz; Packer, Milton; Coats, Andrew J S; Fowler, Michael B; Krum, Henry; Mohacsi, Paul; Rouleau, Jean L; Tendera, Michal; Castaigne, Alain; Trawinski, Jürgen; Amann-Zalan, Ildiko; Hoersch, Silke; Katus, Hugo A
2004-03-15
Neither profiles nor prognostic value of cardiac N-terminal proBNP (NT-proBNP) have been prospectively evaluated in a sufficient number of patients with severe chronic heart failure (CHF) treated with carvedilol or placebo. Baseline and follow-up plasma concentrations of NT-proBNP were measured in the European part of the COPERNICUS Trial. This study enrolled patients with an ejection fraction <25% and symptoms of CHF at rest or on minimal exertion, equally randomized to placebo or carvedilol. NT-proBNP concentrations were increased at baseline (mean+/-S.D.=579+/-822 pmol/l, median=322.5 pmol/l) with a marked decrease during follow-up in the carvedilol, but not in the placebo group. One-year mortality rates were 3.9, 12 and 27.9% in the lower, middle and upper tertiles of NT-proBNP, respectively. When mortality was calculated separately in the placebo and carvedilol group, rates were 0.8, 6.3 and 19.1% in the carvedilol treated but 6.7, 17.9 and 36.9% in the placebo treated patients. NT-proBNP was a powerful predictor of subsequent all-cause mortality in patients with severe CHF. This marker should therefore be further evaluated for risk stratification and monitoring of therapy in CHF.
Ziman, Melanie E; Bui, Hien T; Smith, Craig S; Tsukiji, Lori A; Asmatey, Veda M; Chu, Steven B; Miano, John S
2012-04-01
This single-center retrospective pilot program's objective was to utilize outpatient pharmacists to improve laboratory test adherence in chronic heart failure (CHF) patients overdue for thyroid function testing, thereby demonstrating the value of the outpatient pharmacist and justifying possible clinical role expansion. Thyroid disorders may contribute to CHF development, progression, and exacerbation. Testing is the standard of care in CHF patients per American Heart Association's 2009 Guidelines. Delinquency was defined as labs not conducted within 1 year in patients with euthyroid history, within 6 months in patients with thyroid dysfunction, abnormal labs at any time without follow-up, or lab absence after thyroid medication initiation, adjustment, or discontinuation. Targeted 80 nonpregnant adult CHF patients with delinquent thyroid function tests were counseled to get thyroid labs at point of sale, via telephone, e-mail, or letter. In collaboration with physicians, pharmacists ordered thyroid-stimulating hormone (TSH) and free T4 (FT4) labs. For patients with abnormal laboratory results, pharmacists coordinated drug therapy and follow-up labs. Data were collected from November 1, 2009 to March 30, 2010. Seventy-two patients (90%) previously delinquent for thyroid function testing received relevant thyroid labs. Ten patients (12.5%) with abnormal thyroid function tests not on prior drug therapy received treatment.
Ishino, Mitsunori; Takeishi, Yasuchika; Niizeki, Takeshi; Watanabe, Tetsu; Nitobe, Joji; Miyamoto, Takuya; Miyashita, Takehiko; Kitahara, Tatsuro; Suzuki, Satoshi; Sasaki, Toshiki; Bilim, Olga; Kubota, Isao
2008-11-01
B-type natriuretic peptide (BNP), heart-type fatty acid-binding protein (H-FABP), and pentraxin 3 (PTX3) each predict adverse cardiac events in chronic heart failure (CHF) patients. For prognostic evaluation from different aspects, the utility of combined measurement of the 3 biomarkers in patients with CHF was examined in the present study. Levels of BNP (associated with left ventricular dysfunction, positive if >200 pg/ml), H-FABP (marker of myocardial damage, positive if >4.1 ng/ml), and PTX3 (marker of inflammation, positive if >4.0 ng/ml) were measured in 164 consecutive CHF patients, and patients were prospectively followed with endpoints of cardiac death or rehospitalization. When patients were categorized on the basis of the number of elevated biomarkers, patients with 1, 2, and 3 elevated biomarkers had a 5.4-fold (not significant), 11.2-old (p<0.05), and 34.6-fold increase (p<0.01), respectively, in the risk of adverse cardiac events compared with those without elevated biomarkers. Kaplan-Meier analysis revealed that patients with 3 elevated biomarkers had a significantly higher cardiac event rate than patients with a lower number of elevated biomarkers. The combination of these 3 biomarkers could reliably risk-stratify CHF patients for prediction of cardiac events.
Logar, Ivana; Brouwer, Roy; Maurer, Max; Ort, Christoph
2014-11-04
Contamination of freshwater with micropollutants (MPs) is a growing concern worldwide. Even at very low concentrations, MPs can have adverse effects on aquatic ecosystems and possibly also on human health. Switzerland is one of the first countries to start implementing a national policy to reduce MPs in the effluents of municipal sewage treatment plants (STPs). This paper estimates the benefits of upgrading STPs based on public's stated preferences. To assess public demand for the reduction of the environmental and health risks of MPs, we conducted a choice experiment in a national online survey. The results indicate that the average willingness to pay per household is CHF 100 (US$ 73) annually for reducing the potential environmental risk of MPs to a low level. These benefits, aggregated over households in the catchment of the STPs to be upgraded, generate a total annual economic value of CHF 155 million (US$ 113 million). This compares with estimated annual costs for upgrading 123 STPs of CHF 133 million (US$ 97 million) or CHF 86 (US$ 63) per household connected to these STPs. Hence, a cost-benefit analysis justifies the investment decision from an economic point of view and supports the implementation of the national policy in the ongoing political discussion.
Iyngkaran, Pupalan; Beneby, Glen S
2015-12-26
Congestive heart failure (CHF) is a chronic condition, requiring polypharmacy, allied health supports and regular monitoring. All these factors are needed to ensure compliance and to deliver the positive outcomes demonstrated from randomized controlled trials. Unfortunately many centers around the world are unable to match trial level support. The outcomes for many communities are thus unclear. Research design factors in post-marketing surveillance to address this issue. Phase 4 studies is the name given to trials designed to obtain such community level data and thus address issues of external validity. CHF phase 4 studies are relatively underutilized. We feel the onus for this research lies with the health profession. In this commentary we provide arguments as to why phase 4 studies should be viewed as a social and corporate responsibility of health professional that care for clients with CHF.
[The risk factors for worsening renal function in patients with chronic heart failure].
Yang, Xiao-hong; Sun, Zhi-jun; Zheng, Li-qiang; Jia, Yuan-chun; Dong, Ling-ling
2011-07-01
To investigate the risk factors of worsening renal function (WRF) in patients with chronic heart failure (CHF) and WRF influence on prognosis. A case-control study were undertaken to analyze independent risk factor statistically related to incidence of WRF, and to assess the influence of WRF on prognosis. The independent predictors of WRF were creatinine level at admission (OR 2.248, 95%CI 1.088 - 4.647, P = 0.029) and NYHA class on admission (OR 2.485, 95%CI 1.385 - 4.459, P = 0.002). The mortality of patient with WRF was obviously higher than that of control group during hospitalization (OR 3.824, 95%CI 2.452 - 5.637, P < 0.015). WRF is a common complication among patients hospitalized for CHF, and is obviously associated with mortality during hospitalization. Higher creatinine level and weak heart function are independent risk factors for incidence of WRF of patients with CHF.
What is the risk of hyperkalaemia in heart failure?
Bielecka-Dabrowa, Agata; Rysz, Jacek; Mikhailidis, Dimitri P; Banach, Maciej
2011-10-01
Chronic heart failure (CHF) is the only major cardiovascular disease whose prevalence and incidence are thought to be increasing. Potassium balance may be lost both through the neurohormonal mechanisms involved in cardiovascular diseases and through the drugs used in their treatment. Avoiding both hypo- and hyperkalemia is difficult but beneficial in CHF. Aldosterone production is decreased in the elderly, diabetic patients, and those receiving drugs that block the production or action of renin and angiotensin II. As a result, these groups, as well as those with already impaired potassium excretion due to progressive age or disease-related decline in glomerular filtration rate, are particularly vulnerable to the development of hyperkalemia. Evidence from several studies suggests that, in patients with CHF, serum potassium should be maintained between 4.0 and 5.5 mEq/L. To gain the maximum benefit from aldosterone antagonists it is necessary to individualize their use; it is also necessary to carefully monitor electrolytes.
Iyngkaran, Pupalan; Beneby, Glen S
2015-01-01
Congestive heart failure (CHF) is a chronic condition, requiring polypharmacy, allied health supports and regular monitoring. All these factors are needed to ensure compliance and to deliver the positive outcomes demonstrated from randomized controlled trials. Unfortunately many centers around the world are unable to match trial level support. The outcomes for many communities are thus unclear. Research design factors in post-marketing surveillance to address this issue. Phase 4 studies is the name given to trials designed to obtain such community level data and thus address issues of external validity. CHF phase 4 studies are relatively underutilized. We feel the onus for this research lies with the health profession. In this commentary we provide arguments as to why phase 4 studies should be viewed as a social and corporate responsibility of health professional that care for clients with CHF. PMID:26713277
Morozova, T E; Ivanova, E P; Rykova, S M
2011-01-01
To study clinical and pharmacoeconomical aspects of trimetazidine MD as a component of complex therapy of chronic heart failure (CHF) in patients with cardiac rhythm disturbances. In 82 patients (67 men, 15 women, mean age 62.2+/-7.3 years) with II-III functional class (FC) of CHF we studied effect of addition of therapy with trimetazidine MB to standard therapy on CHF FC, parameters of Holter monitoring (HM) of ECG and treadmill test. In analysis of HM we considered number of isolated and paired ventricular extrasystoles (VE), episodes of nonsustained ventricular tachycardia (VT), duration of episodes of ST segment depression on 24-hour ECG. Pharmacoeconomical analysis of 2 therapy regimes was conducted by the method of calculation of cost/efficacy ratio for each parameter. Stabilization of state was achieved before study in all patients at the background of standard therapy with angiotensin converting enzyme inhibitors, cardiac glycosides, diuretics, beta-adrenoblockers. At the background of this therapy trimetazidine MB in the dose of 70 mg/day was added to 40 patients of group 1 while 42 patients of group 2 received standard therapy without trimetazidine MB. After 16 weeks of treatment CHF FC lowered 11% (<0.05) 10% (<0.05) in groups 1 and 2, respectively. According to data of HM numbers of VE decreased in group 1 by 57.6% (<0.05), in group 2 by 28.8% (<0.05), episodes of nonsustained VT--by 58.3% (<0,05) and 36.8% (<0.05), isolated VE--by 23.6% (>0.05) and 6.9% (>0.05), respectively. Duration of episodes of ST depression decreased 55.5% (<0.05) in group 1 and 23.3% (<0.05) in group 2. According to treadmill test maximal power of load in patients of group 1 rose 12.3% (<0.05), of group 2-6.7% (<0.05), total exercise duration rose 16.8% (<0.05) and 82% (<0.05), respectively. Cost/efficacy ratio expressed in roubles per 1% efficacy calculated for CHF FC was 2694 in group 1, 4095--in group 2; for maximal load power--2409 and 3667, respectively; for duration of episodes of ST segment depression--1665 and 1934, respectively; for dynamics of VE number--514 and 853, respectively. Supplementation of standard CHF therapy with therapy with metabolic cytoprotector trimetazidine MB allows to achieve more pronounced positive effect on CHF FC, exercise tolerance, and lowering of cardiac ectopic activity. Smallest cost efficacy ratio after addition of trimetazidine MB to standard therapy from pharmacoeconomical point of view evidence for advantages of this regime of therapy possessing smaller expenditures per unit of efficacy.
Serebruany, Victor L; Malinin, Alex I; Jerome, Scott D; Lowry, David R; Morgan, Athol W; Sane, David C; Tanguay, Jean-François; Steinhubl, Steven R; O'connor, Christopher M
2003-10-01
Persistent platelet activation may contribute to thrombotic events in patients with congestive heart failure (CHF). Chronic use of mild platelet inhibitors could therefore represent an independent avenue to improve morbidity, mortality, and quality of life in this expanding population. Although clopidogrel is widely used in patients with acute coronary syndromes and ischemic stroke, the ability of this novel ADP-receptor antagonist to inhibit platelet function in patients with CHF is unknown. We assessed antiplatelet properties of clopidogrel with aspirin (C+A) versus aspirin alone (A) in patients with CHF with heightened platelet activity. Patients with left ventricular ejection fraction <40%, or CHF symptoms in the setting of preserved systolic function and New York Heart Association class II-IV were screened. Patients were considered to have platelet activation when 4 of the following 5 parameters were met: ADP-induced platelet aggregation >60%; collagen-induced aggregation >70%; whole blood aggregation >18 ohms; expression of GP IIb/IIIa >220 log MFI; and P-selectin cell positivity >8%. All patients were treated with 325 mg of acetylsalycilic acid (ASA) for at least 1 month. Patients receiving an antithrombotic agent other than ASA were excluded. Patients meeting clinical and laboratory criteria were randomly assigned to C+A (n=25), A (n=25) groups, or represent screen failures (n=38). Platelet studies (conventional and whole blood aggregometry, shear-induced activation, expression of 10 major receptors and formation of platelet-leukocyte microparticles) were performed at baseline and after 30 days of therapy. There were no deaths, hospitalizations, or serious adverse events. There were no changes in platelet parameters in the A group. In contrast, therapy with C+A resulted in a significant inhibition of platelet activity assessed by ADP-induced (P =.00001), and epinephrine-induced (P =.0016) aggregation, closure time (P =.04), expression of PECAM-1 (P =.009), GP Ib (P =.006), GP IIb/IIIa antigen (P =.0001), GP IIb/IIIa activity with PAC-1 (P =.0021), and CD151 (P =.0026) when compared with the A group. Therapy with C+A also resulted in the reduced formation of platelet-leukocyte microparticles (P =.021). Collagen-induced aggregation in plasma and in whole blood, expression of vitronectin receptor, P-selectin, CD63, CD107a, and CD107b did not differ among groups. Treatment with C+A for 1 month provides significantly greater inhibition of platelet activity than ASA alone in patients with CHF. Patients with CHF with heightened platelet activity represent a potential target population in which addition of clopidogrel may decrease mortality rates by reducing the incidence of thrombotic vascular events.
Torasemide: a pharmacoeconomic review of its use in chronic heart failure.
Young, M; Plosker, G L
2001-01-01
Torasemide is a loop diuretic used for the treatment of hypertension and for oedema in chronic heart failure (CHF), renal failure and cirrhosis. The efficacy of torasemide in reducing salt and water retention in CHF has been established in double-blind comparative studies against furosemide. Torasemide has been shown to be at least as effective as furosemide in terms of total volume of urine excreted and also has a longer duration of action. The efficacy of torasemide (in terms of improved CHF symptoms and reduced pulmonary congestion, oedema and bodyweight) has been shown in randomised controlled trials and confirmed in large postmarketing studies. In addition, data from postmarketing studies have shown that patients receiving torasemide had significantly reduced hospital admission rates compared with patients receiving furosemide. Pharmacoeconomic assessments of torasemide have focused on its effect in reducing hospitalisation. Hospitalisation costs due to CHF decreased by 86% during the 11.2-month period of torasemide treatment, compared with the 6-month period prior to treatment, in a US retrospective study assessing medical and pharmacy claims data. Overall, average monthly costs for patients decreased by 56.6% after 5.1 months (from $US1,897.28 to $US823.70 per patient per month; PPPM), and by 76% after 11.2 months (from $US1,944.76 to $US470.76 PPPM) of torasemide treatment. In the furosemide group, average monthly costs for patients increased moderately from $US227.28 to $US261.18 PPPM after 12 months. Direct comparison of the torasemide and furosemide study groups was not possible because the group receiving torasemide had much higher healthcare resource use at baseline. Compared with furosemide, torasemide was associated with reduced rates of hospital admissions for CHF and/or cardiovascular causes in 3 studies, a retrospective analysis conducted in Germany, a prospective US study of patients enrolled from hospital admissions and a decision-analysis model. As a result, the direct costs of treatment for CHF or cardiovascular diseases for patients treated with torasemide were less than those with furosemide. However, in the US study, there was no statistically significant difference in hospital admissions for all causes and/or in overall direct medical costs, although the study was not powered to show this. In another US study of managed care patients with New York Heart Association (NYHA) class II or III CHF, no difference in clinical or economic outcomes was observed between patients taking torasemide or furosemide; despite the higher acquisition costs for torasemide, total costs were similar for both groups. Torasemide was found to be more cost effective than furosemide in terms of cost per patient with improved functional (NYHA) class of CHF severity in a retrospective German analysis, although this measure is not ideal. This study also evaluated indirect costs (for loss of productivity of employed patients) and resultssuggest torasemide has a favourable effect in reducing days off work compared with furosemide, although the population of employed patients in the study was very small. Torasemide has been shown to improve some measures of quality of life in 2 studies. It was associated with higher quality-of-life scores than furosemide in a 6-month study, but the differences were only significant at month 4. In another study, torasemide significantly improved fatigue, but full study details are yet to be published. Despite the higher acquisition cost of torasemide over furosemide, pharmacoeconomic analyses have shown that torasemide is likely to reduce overall treatment costs of CHF by reducing hospital admissions and readmissions. Torasemide has generally shown clinical and economic advantages over furosemide, although more long term data are needed to confirm these results and to further investigate effects on quality of life. There are limitations to the currently available pharmacoeconomic data, but present data support the use of torasemide as a first-line option for diuretic therapy in patients with CHF presenting with oedema and especially in those patients not achieving relief of symptoms with furosemide.
Schmid, Jean‐Paul; Noveanu, Markus; Morger, Cyrill; Gaillet, Raymond; Capoferri, Mauro; Anderegg, Matthias; Saner, Hugo
2007-01-01
Background Whole‐body water immersion leads to a significant shift of blood from the periphery to the intrathoracic circulation, followed by an increase in central venous pressure and heart volume. In patients with severely reduced left ventricular function, this hydrostatically induced volume shift might overstrain the cardiovascular adaptive mechanisms and lead to cardiac decompensation. Aim To assess the haemodynamic response to water immersion, gymnastics and swimming in patients with chronic heart failure (CHF). Methods 10 patients with compensated CHF (62.9 (6.3) years, ejection fraction 31.5% (4.1%), peak oxygen consumption (V̇o2) 19.4 (2.8) ml/kg/min), 10 patients with coronary artery disease (CAD) but preserved left ventricular function (57.2 (5.6) years, ejection fraction 63.9% (5.5%), peak V̇o2 28 (6.3) ml/kg/min), and 10 healthy controls (32.8 (7.2) years, peak V̇o2 45.6 (6) ml/kg/min) were examined. Haemodynamic response to thermoneutral (32°C) water immersion and exercise was measured using a non‐invasive foreign gas rebreathing method during stepwise water immersion, water gymnastics and swimming. Results Water immersion up to the chest increased cardiac index by 19% in controls, by 21% in patients with CAD and by 16% in patients with CHF. Although some patients with CHF showed a decrease of stroke volume during immersion, all subjects were able to increase cardiac index (by 87% in healthy subjects, by 77% in patients with CAD and by 53% in patients with CHF). V̇o2 during swimming was 9.7 (3.3) ml/kg/min in patients with CHF, 12.4 (3.5) ml/kg/min in patients with CAD and 13.9 (4) ml/kg/min in controls. Conclusions Patients with severely reduced left ventricular function but stable clinical conditions and a minimal peak V̇o2 of at least 15 ml/kg/min during a symptom‐limited exercise stress test tolerate water immersion and swimming in thermoneutral water well. Although cardiac index and V̇o2 are lower than in patients with CAD with preserved left ventricular function and controls, these patients are able to increase cardiac index adequately during water immersion and swimming. PMID:17164483
Combined assessment of myocardial damage and electrical disturbance in chronic heart failure
Kadowaki, Shinpei; Watanabe, Tetsu; Otaki, Yoichiro; Narumi, Taro; Honda, Yuki; Takahashi, Hiroki; Arimoto, Takanori; Shishido, Tetsuro; Miyamoto, Takuya; Kubota, Isao
2017-01-01
AIM To investigate feasibility of combined assessment of biochemical and electrophysiological myocardial impairment markers risk-stratifying patients with chronic heart failure (CHF). METHODS Serum levels of heart-type fatty acid binding protein (H-FABP) as a marker of ongoing myocardial damage and QRS duration on electrocardiogram were measured at admission in 322 consecutive patients with CHF. A prolonged QRS duration was defined as 120 ms or longer. The cut-off value for H-FABP level (4.5 ng/mL) was determined from a previous study. Patients were prospectively followed during a median follow up period of 534 d. The primary endpoint was cardiac deaths and rehospitalization for worsening CHF. RESULTS There were 117 primary events, including 27 cardiac deaths and 90 rehospitalizations. Patients were stratified into four groups according to H-FABP level and QRS duration (≥ 120 ms). Multivariate analysis demonstrated that high H-FABP levels [hazard ratio (HR) = 1.745, P = 0.021] and QRS prolongation (HR 1.612, P = 0.0258) were independent predictors of cardiac events. Kaplan-Meier analysis demonstrated that the combination of high H-FABP levels and QRS prolongation could be used to reliably stratify patients at high risk for cardiac events (log rank test P < 0.0001). CONCLUSION Combined assessment of myocardial damage and electrical disturbance can be used to risk-stratify patients with CHF. PMID:28603594
Philbin, E F; Weil, H F; Erb, T A; Jenkins, P L
1999-08-01
Severity of illness, treatment choices, and clinical outcomes may vary with physician training. This study was performed to determine whether such differences exist among patients with congestive heart failure (CHF) treated by cardiologists and by noncardiologists in the community hospital setting. Prospective cohort study. Ten acute-care community hospitals. PATIENTS, MEASUREMENTS, AND RESULTS: Two thousand four hundred fifty-four patients with CHF were identified and followed up for 6 months after hospital discharge. Patients who were not treated by a cardiologist (group I; n = 977) were compared with patients whose attending physician was a cardiologist (group II; n = 419) and patients who received consultative care from a cardiologist (group III; n = 1,058). When compared with group I patients, group II patients were more likely to receive the recommended diagnostic tests and treatment strategies, although some of these differences could be explained by variations in the case mix. Group II patients had higher hospital charges, but lower CHF readmission rates and better postdischarge quality-of-life measures. No differences in adjusted mortality rates were observed. In the community-hospital setting, the clinical practices of cardiologists are more compatible with published treatment guidelines than the clinical practices of other physicians. The benefits of cardiology specialty care include lower CHF readmission rates and better postdischarge quality-of-life measures, rather than lower mortality rates, fewer hospital charges, or shorter length of stay.
Mohammadzadeh, Niloofar; Safdari, Reza; Rahimi, Azin
2013-09-01
Given the importance of the follow-up of chronic heart failure (CHF) patients to reduce common causes of re-admission and deterioration of their status that lead to imposing spiritual and physical costs on patients and society, modern technology tools should be used to the best advantage. The aim of this article is to explain key points which should be considered in designing an appropriate multi-agent system to improve CHF management. In this literature review articles were searched with keywords like multi-agent system, heart failure, chronic disease management in Science Direct, Google Scholar and PubMed databases without regard to the year of publications. Agents are an innovation in the field of artificial intelligence. Because agents are capable of solving complex and dynamic health problems, to take full advantage of e-Health, the healthcare system must take steps to make use of this technology. Key factors in CHF management through a multi-agent system approach must be considered such as organization, confidentiality in general aspects and design and architecture points in specific aspects. Note that use of agent systems only with a technical view is associated with many problems. Hence, in delivering healthcare to CHF patients, considering social and human aspects is essential. It is obvious that identifying and resolving technical and non-technical challenges is vital in the successful implementation of this technology.
Mohammadzadeh, Niloofar; Rahimi, Azin
2013-01-01
Objectives Given the importance of the follow-up of chronic heart failure (CHF) patients to reduce common causes of re-admission and deterioration of their status that lead to imposing spiritual and physical costs on patients and society, modern technology tools should be used to the best advantage. The aim of this article is to explain key points which should be considered in designing an appropriate multi-agent system to improve CHF management. Methods In this literature review articles were searched with keywords like multi-agent system, heart failure, chronic disease management in Science Direct, Google Scholar and PubMed databases without regard to the year of publications. Results Agents are an innovation in the field of artificial intelligence. Because agents are capable of solving complex and dynamic health problems, to take full advantage of e-Health, the healthcare system must take steps to make use of this technology. Key factors in CHF management through a multi-agent system approach must be considered such as organization, confidentiality in general aspects and design and architecture points in specific aspects. Conclusions Note that use of agent systems only with a technical view is associated with many problems. Hence, in delivering healthcare to CHF patients, considering social and human aspects is essential. It is obvious that identifying and resolving technical and non-technical challenges is vital in the successful implementation of this technology. PMID:24195010
Miján, Alberto; Martín, Elvira; de Mateo, Beatriz
2006-05-01
Chronic heart failure (CHF), especially affecting the right heart, frequently leads to malnutrition. If the latter is severe and is combined to other factors, it may lead to cardiac cachexia. This one is associated to increased mortality and lower survival of patients suffering from it. The causes of cardiac cachexia are diverse, generally associated to maintenance of a negative energy balance, with increasing evidence of its multifactorial origin. Neurohumoral, inflammatory, immunological, and metabolic factors, among others, are superimposed in the patient with CHF, leading to involvement and deterioration of several organs and systems, since this condition affects both lean (or active cellular) mass and adipose and bone tissue osteoporosis. Among all, the most pronounced deterioration may be seen at skeletal muscle tissue, at both structural and functional levels, the heart not being spared. As for treatment, it should be based on available scientific evidence. Assessment of nutritional status of any patient with CHF is a must, with the requirement of nutritional intervention in case of malnutrition. In this situation, especially if accompanied by cardiac cachexia, it is required to modify energy intake and oral diet quality, and to consider the indication of specific complementary or alternative artificial nutrition. Besides, the causal relationship of the beneficial role of moderate physical exertion is increasing, as well as modulation of metabolic and inflammatory impairments observed in cardiac cachexia with several drugs, leading to a favorable functional and structural response in CHF patients.
Leizorovicz, Alain; Lechat, Philippe; Cucherat, Michel; Bugnard, Françoise
2002-02-01
Despite the available evidence from randomized clinical trials, beta-blockers are often not used optimally in patients with congestive heart failure (CHF). This meta-analysis aims at providing a precise and quantitative estimate of the benefit and risks of long-term bisoprolol on major clinical events in patients with CHF, both overall and in selected subgroups. This may help clinicians in their decisions as to whether to prescribe bisoprolol for their individual patients. Meta-analysis was performed of results from the 2 randomized, controlled clinical studies in which bisoprolol was compared with placebo (Cardiac Insufficiency Bisoprolol Study [CIBIS and CIBIS II]), which included 3288 patients with proven CHF. The main outcomes were total death, cardiovascular death, sudden death, hospitalization for heart failure, and myocardial infarction. A highly significant 29.3% relative reduction of death (17%, 40%; P =.00003) was observed, as well as significant risk reduction in cardiovascular death and sudden death in favor of bisoprolol. Also, a highly significant relative reduction of 18.4% (25%, 11%; P =.00001) in hospital admission or death was observed. A similar relative reduction of death was consistently observed in selected subgroups of patients. Bisoprolol prevents major cardiovascular events in patients with CHF with a high benefit-to-risk ratio and can be recommended for these patients.
Singer, R B
2000-01-01
Several clinical trials of drug treatment of patients with congestive heart failure (CHF) have previously been reported as Mortality Abstracts in the Journal of Insurance Medicine. Results are presented here for two similar clinical trials reported in September 1999 and compared with the previous results. In a recent international multicenter clinical trial, excess mortality in terms of excess death rates (EDRs) was reduced from 195 per 1000 per year in the placebo group to 139 in the group treated with Spironolactone. There was no significant reduction in the Danish multicenter study of Dofetilide to convert the atrial fibrillation (AF) to a normal rhythm in the 25% of the CHF patients who had AF (EDR was 224 in the placebo group and 216 in the Dofetilide group). In both of these studies, there were more patients with severe CHF than in the previous studies and the EDR values were higher. Results from the Danish study by severity according to the New York Heart Association (NYHA) classification show a progressive increase in EDR from 173 in class 2 to 237 in class 3 to 392 in class 4. Excess mortality in symptomatic CHF is far outside the issue limits for individual life insurance, but these results are of potential utility for the underwriting of such cases for structured settlement annuities.
Fukui, Miho; Tsujino, Takeshi; Hirotani, Shinichi; Ito, Hiroshi; Yamamoto, Kazuhiro; Akasaka, Takashi; Hirano, Yutaka; Ohte, Nobuyuki; Daimon, Takashi; Nakatani, Satoshi; Kawabata, Masaaki; Masuyama, Tohru
2017-07-01
We have previously reported that a long-acting loop diuretic, azosemide, reduces cardiovascular risks in patients with chronic heart failure (CHF) as compared with a short-acting one, furosemide, in Japanese Multicenter Evaluation of LOng- versus short-acting Diuretics In Congestive heart failure (J-MELODIC). However, the mechanisms of the difference have not been elucidated. This study aimed to examine whether there is a difference in the reduction in plasma brain natriuretic peptide (BNP) level and in left ventricular (LV) functional recovery between the CHF patients treated with the long-acting diuretic (the azosemide group) and the short-acting diuretic (the furosemide group). We reviewed changes in plasma BNP level and echo-assessed LV functional parameters from baseline to a year after the entry in 288 CHF patients with New York Heart Association class II or III symptoms that joined J-MELODIC. The decrease in plasma BNP levels was larger in the azosemide group than in the furosemide group (p < 0.01). The changes in echocardiographic parameters were not more favorable in the azosemide group than in the furosemide group. In conclusion, the decrease in plasma BNP levels was larger in the azosemide group than in the furosemide group. These findings may account for the better prognosis in CHF patients treated with azosemide than those with furosemide in J-MELODIC.
Experiences of air travel in patients with chronic heart failure
Ingle, Lee; Hobkirk, James; Damy, Thibaud; Nabb, Samantha; Clark, Andrew L.; Cleland, John G.F.
2012-01-01
Aim To conduct a survey in a representative cohort of ambulatory patients with stable, well managed chronic heart failure (CHF) to discover their experiences of air travel. Methods An expert panel including a cardiologist, an exercise scientist, and a psychologist developed a series of survey questions designed to elicit CHF patients' experiences of air travel (Appendix 1). The survey questions, information sheets and consent forms were posted out in a self-addressed envelope to 1293 CHF patients. Results 464 patients (response rate 39%) completed the survey questionnaires. 54% of patients had travelled by air since their heart failure diagnosis. 20% of all patients reported difficulties acquiring travel insurance. 65% of patients who travelled by air experienced no health-related problems. 35% of patients who travelled by air experienced health problems, mainly at the final destination, going through security and on the aircraft. 27% of all patients would not travel by air in the future. 38% of patients would consider flying again if there were more leg room on the aeroplane, if their personal health improved (18%), if they could find cheaper travel insurance (19%), if there were less waiting at the airport (11%), or if there were less walking/fewer stairs to negotiate at the airport (7%). Conclusion For most patients in this sample of stable, well managed CHF, air travel was safe. PMID:21256607
Inorganic Bi/In thermal resist as a high-etch-ratio patterning layer for CF4/CHF3/O2 plasma etch
NASA Astrophysics Data System (ADS)
Tu, Yuqiang; Chapman, Glenn H.; Peng, Jun
2004-05-01
Bimetallic thin films containing indium and with low eutectic points, such as Bi/In, have been found to form highly sensitive thermal resists. They can be exposed by lasers with a wide range of wavelengths and be developed by diluted RCA2 solutions. The exposed bimetallic resist Bi/In can work as an etch masking layer for alkaline-based (KOH, TMAH and EDP) "wet" Si anisotropic etching. Current research shows that it can also act as a patterning and masking layer for Si and SiO2 plasma "dry" etch using CF4/CHF3. The profile of etched structures can be tuned by adding CHF3 and other gases such as Ar, and by changing the CF4/CHF3 ratio. Depending on the fluorocarbon plasma etching recipe the etch rate of laser exposed Bi/In can be as low as 0.1nm/min, 500 times lower than organic photoresists. O2 plasma ashing has little etching effect on exposed Bi/In, indicating that laser exposure is an oxidation process. Experiment result shows that single metal Indium film and bilayer Sn/In exhibit thermal resist characteristics but at higher exposure levels. They can be developed in diluted RCA2 solution and used as etch mask layers for Si anisotropic etch and plasma etch.
Frères, Pierre; Bouznad, Nassim; Servais, Laurence; Josse, Claire; Wenric, Stéphane; Poncin, Aurélie; Thiry, Jérôme; Moonen, Marie; Oury, Cécile; Lancellotti, Patrizio; Bours, Vincent; Jerusalem, Guy
2018-01-29
Over time, the chance of cure after the diagnosis of breast cancer has been increasing, as a consequence of earlier diagnosis, improved diagnostic procedures and more effective treatment options. However, oncologists are concerned by the risk of long term treatment side effects, including congestive heart failure (CHF). In this study, we evaluated innovative circulating cardiac biomarkers during and after anthracycline-based neoadjuvant chemotherapy (NAC) in breast cancer patients. Levels of cardiac-specific troponins T (cTnT), N-terminal natriuretic peptides (NT-proBNP), soluble ST2 (sST2) and 10 circulating microRNAs (miRNAs) were measured. Under chemotherapy, we observed an elevation of cTnT and NT-proBNP levels, but also the upregulation of sST2 and of 4 CHF-related miRNAs (miR-126-3p, miR-199a-3p, miR-423-5p, miR-34a-5p). The elevations of cTnT, NT-proBNP, sST2 and CHF-related miRNAs were poorly correlated, suggesting that these molecules could provide different information. Circulating miRNA and sST2 are potential biomarkers of the chemotherapy-related cardiac dysfunction (CRCD). Nevertheless, further studies and long-term follow-up are needed in order to evaluate if these new markers may help to predict CRCD and to identify the patients at risk to later develop CHF.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Metzler, Dominik; Li, Chen; Engelmann, Sebastian
With the increasing interest in establishing directional etching methods capable of atomic scale resolution for fabricating highly scaled electronic devices, the need for development and characterization of atomic layer etching (ALE) processes, or generally etch processes with atomic layer precision, is growing. In this work, a flux-controlled cyclic plasma process is used for etching of SiO 2 and Si at the Angstrom-level. This is based on steady-state Ar plasma, with periodic, precise injection of a fluorocarbon (FC) precursor (C 4F 8 and CHF 3), and synchronized, plasma-based Ar+ ion bombardment [D. Metzler et al., J Vac Sci Technol A 32,more » 020603 (2014), and D. Metzler et al., J Vac Sci Technol A 34, 01B101 (2016)]. For low energy Ar+ ion bombardment conditions, physical sputter rates are minimized, whereas material can be etched when FC reactants are present at the surface. This cyclic approach offers a large parameter space for process optimization. Etch depth per cycle, removal rates, and self-limitation of removal, along with material dependence of these aspects, were examined as a function of FC surface coverage, ion energy, and etch step length using in situ real time ellipsometry. The deposited FC thickness per cycle is found to have a strong impact on etch depth per cycle of SiO 2 and Si, but is limited with regard to control over material etching selectivity. Ion energy over the 20 to 30 eV range strongly impacts material selectivity. The choice of precursor can have a significant impact on the surface chemistry and chemically enhanced etching. CHF 3 has a lower FC deposition yield for both SiO 2 and Si, and also exhibits a strong substrate dependence of FC deposition yield, in contrast to C4F 8. The thickness of deposited FC layers using CHF 3 is found to be greater for Si than for SiO 2. X-ray photoelectron spectroscopy was used to study surface chemistry. When thicker FC films of 11 Å are employed, strong changes of FC film chemistry during a cycle are seen whereas the chemical state of the substrate varies much less. On the other hand, for FC film deposition of 5 Å for each cycle, strong substrate surface chemical changes are seen during an etching cycle. The nature of this cyclic etching with periodic deposition of thin FC films differs significantly from conventional etching with steady-state FC layers since surface conditions change strongly throughout each cycle.« less
MacKenzie, Emma; Smith, Amanda; Angus, Neil; Menzies, Sue; Brulisauer, Franz; Leslie, Stephen J
2010-01-01
The treatment of patients with chronic heart failure (CHF) remains sub-optimal. Specialist CHF nurses are proven to improve care and reduce admission but developing such services, especially in remote areas, can be difficult. This study aimed: first, to assess the perceived acceptability and effectiveness of a new community based nurse-led heart failure service by general practitioners (GPs) in an area with a dispersed population; second, to assess the knowledge and learning needs of GPs; and third, to assess perceptions of the use of national guidelines and telehealth on heart failure management. The study was conducted in the Scottish Highlands, a large geographical area in the north of the UK which includes both rural and urban populations. The area has a total population of 240 000, approximately 60% of whom are within 1 hour travel time of the largest urban centre. A postal survey of all GPs (n = 260) and structured email survey of all CHF specialist nurses (n = 3) was performed. All responses were entered into a Microsoft Excel spreadsheet, summarised and subjected to thematic analysis. Differences between GPs in 'rural', 'urban' or both 'urban & rural' was investigated using an F-test for continuous variables and a three-sample test for equality of proportions for nominal data. Questionnaires were returned from 83 GPs (32%) and all three CHF specialist nurses. In this sample there were only a few differences between GPs from 'rural', 'urban' and 'urban & rural'. There also appeared to be little difference in responses between those who had the experience of the CHF nurse service and those who had not. Overall, 32 GPs (39%) wished better, local access to echocardiography, while 63 (76%) wished access to testing for brain natriuretic peptide (BNP). Only 27 GPs (33%) referred all patients with CHF to hospital. A number of GPs stated that this was dependant on individual circumstances and the patient's ability to travel. The GPs were confident to initiate standard heart failure drugs although only 54 (65%) were confident in the initiation of beta-blockers. Most GPs (69%) had had experience of the CHF specialist nurse service and the responses were mixed. The GPs who had experienced the service appeared less confident that it would lead to reduced admission of patients to hospital (51% vs 77%, p = 0.046). Three main themes emerged from the nurse responses: service planning, communication and attitudinal changes after service embedment. This study demonstrates that a community based heart failure nurse service was not universally valued. Differences between urban and rural localities (communication) suggest that models of care derived from evidence based practice in urban areas may not be directly transferable to remote areas. Clearly, good communication among staff groups at all stages of implementation is important; however, despite best efforts and clinical trial evidence, specialist nurse services will not be welcomed by all doctors. Service providers and commissioners should be cognisant of the different roles of urban and rural GPs when designing such services. Among GPs there was a high degree of confidence with initiation and titration of drugs for heart failure with the exception of beta-blockers so clearly this is an area of ongoing educational need and support. Education and support should focus on ensuring that all doctors who care for patients with CHF have the skills and confidence to use medical therapies and specialist services as appropriate.
Song, Xiaolong; Qu, Huiyan; Yang, Zongguo; Rong, Jingfeng; Cai, Wan; Zhou, Hua
2017-01-01
Background . Whether additional benefit can be achieved with the use of L-carnitine (L-C) in patients with chronic heart failure (CHF) remains controversial. We therefore performed a meta-analysis of randomized controlled trials (RCTs) to evaluate the effects of L-C treatment in CHF patients. Methods . Pubmed, Ovid Embase, Web of Science, and Cochrane Library databases, Chinese National Knowledge Infrastructure (CNKI) database, Wanfang database, Chinese Biomedical (CBM) database, and Chinese Science and Technology Periodicals database (VIP) until September 30, 2016, were identified. Studies that met the inclusion criteria were systematically evaluated by two reviewers independently. Results . 17 RCTs with 1625 CHF patients were included in this analysis. L-C treatment in CHF was associated with considerable improvement in overall efficacy (OR = 3.47, P < 0.01), left ventricular ejection fraction (LVEF) (WMD: 4.14%, P = 0.01), strike volume (SV) (WMD: 8.21 ml, P = 0.01), cardiac output (CO) (WMD: 0.88 L/min, P < 0.01), and E/A (WMD: 0.23, P < 0.01). Moreover, treatment with L-C also resulted in significant decrease in serum levels of BNP (WMD: -124.60 pg/ml, P = 0.01), serum levels of NT-proBNP (WMD: -510.36 pg/ml, P < 0.01), LVESD (WMD: -4.06 mm, P < 0.01), LVEDD (WMD: -4.79 mm, P < 0.01), and LVESV (WMD: -20.16 ml, 95% CI: -35.65 to -4.67, P < 0.01). However, there were no significant differences in all-cause mortality, 6-minute walk, and adverse events between L-C and control groups. Conclusions . L-C treatment is effective for CHF patients in improving clinical symptoms and cardiac functions, decreasing serum levels of BNP and NT-proBNP. And it has a good tolerance.
Buja, Alessandra; Damiani, Gianfranco; Gini, Rosa; Visca, Modesta; Federico, Bruno; Donato, Daniele; Francesconi, Paolo; Marini, Alessandro; Donatini, Andrea; Brugaletta, Salvatore; Baldo, Vincenzo; Donata Bellentani, Maria
2014-01-01
Background Our interest in chronic conditions is due to the fact that, worldwide, chronic diseases have overtaken infectious diseases as the leading cause of death and disability, so their management represents an important challenge for health systems. The aim of this study was to compare the performance of primary health care services in managing diabetes, congestive heart failure (CHF) and coronary heart disease (CHD), by age group. Methods This population-based retrospective cohort study was conducted in Italy, enrolling 1,948,622 residents ≥16 years old. A multilevel regression model was applied to analyze compliance to care processes with explanatory variables at both patient and district level, using age group as an independent variable, and adjusting for sex, citizenship, disease duration, and Charlson index on the first level, and for District Health Unit on the second level. Results The quality of chronic disease management showed an inverted U-shaped relationship with age. In particular, our findings indicate lower levels for young adults (16–44 year-olds), adults (45–64), and oldest old (+85) than for patients aged 65–74 in almost all quality indicators of CHD, CHF and diabetes management. Young adults (16–44 y), adults (45–64 y), the very old (75–84 y) and the oldest old (+85 y) patients with CHD, CHF and diabetes are less likely than 65–74 year-old patients to be monitored and treated using evidence-based therapies, with the exceptions of echocardiographic monitoring for CHF in young adult patients, and renal monitoring for CHF and diabetes in the very old. Conclusion Our study shows that more effort is needed to ensure that primary health care systems are sensitive to chronic conditions in the young and in the very elderly. PMID:24632818
NASA Astrophysics Data System (ADS)
Boltenko, E. A.
2016-10-01
The results of the experimental study of the heat-transfer crisis on heat-release surfaces of annular channels with swirl and transit flow are presented. The experiments were carried out using electric heated annular channels with one and (or) two heat-release surfaces. For the organization of transit flow on a convex heat-release surface, four longitudinal ribs were installed uniformly at its perimeter. Swirl flow was realized using a capillary wound tightly (without gaps) on the ribs. The ratio between swirl and transit flows in the annular gap was varied by applying longitudinal ribs of different height. The experiments were carried out using a closed-type circulatory system. The experimental data were obtained in a wide range of regime parameters. Both water heated to the temperature less than the saturation temperature and water-steam mixture were fed at the inlet of the channels. For the measurement of the temperature of the heat-release surfaces, chromel-copel thermocouples were used. It was shown that the presence of swirl flow on a convex heatrelease surface led to a significant decrease in critical heat flows (CHF) compared to a smooth surface. To increase CHF, it was proposed to use the interaction of swirl flows of the heat carrier. The second swirl flow was transit flow, i.e., swirl flow with the step equal to infinity. It was shown that CHF values for a channel with swirl and transit flow in all the studied range of regime parameters was higher than CHF values for both a smooth annular channel and a channel with swirl. The empirical ratios describing the dependence of CHF on convex and concave heat-release surfaces of annular channels with swirl and transit flow on the geometrical characteristics of channels and the regime parameters were obtained. The experiments were carried out at the pressure p = 3.0-16.0 MPa and the mass velocity ρw = 250-3000 kg/(m2s).
Wang, Huan; Hou, Lei; Kwak, Dongmin; Fassett, John; Xu, Xin; Chen, Angela; Chen, Wei; Blazar, Bruce R.; Xu, Yawei; Hall, Jennifer L.; Ge, Jun-bo; Bache, Robert J.; Chen, Yingjie
2016-01-01
Congestive heart failure (CHF) is associated with an increase of leukocyte infiltration, pro-inflammatory cytokines and fibrosis in the heart and lung. Regulatory T cells (Tregs, CD4+CD25+FoxP3+) suppress inflammatory responses in various clinical conditions. We postulated that expansion of Tregs attenuates CHF progression by reducing cardiac and lung inflammation. We investigated the effects of Interleukin-2 (IL-2) plus IL-2 monoclonal antibody clone JES6-1 complexes (IL2/JES6-1) on induction of Tregs, transverse aortic constriction (TAC)-induced cardiac and lung inflammation and CHF progression in mice. We demonstrated that end-stage CHF caused a massive increase of lung macrophages and T cells, as well as relatively mild LV leukocyte infiltration. Administration of IL2/JES6-1 caused a ~6-fold increase of Tregs within CD4+ T cells in the spleen, lung and heart of mice. IL2/JES6-1 treatment of mice with existing TAC-induced left ventricular (LV) failure markedly reduced lung and right ventricular (RV) weight, and improved LV ejection fraction and LV end-diastolic pressure. Mechanistically, IL2/JES6-1 treatment significantly increased Tregs, suppressed CD4+ T-cell accumulation, dramatically attenuated leukocyte infiltration including decreasing CD45+ cells, macrophages, CD8+ T cells and effector memory CD8+, and reduced pro-inflammatory cytokine expressions and fibrosis in the lung of mice. Furthermore, IL2/JES6-1 administered before TAC attenuated the development of LV hypertrophy and dysfunction in mice. Our data indicate that increasing Tregs through administration of IL2/JES6-1 effectively attenuates pulmonary inflammation, RV hypertrophy and further LV dysfunction in mice with existing LV failure, suggesting strategies to properly expand Tregs may be useful in reducing CHF progression. PMID:27160197
Mahmood, Samira Abdulla; Pavlovic, Dragan; Hoffmann, Ulrich
2009-05-07
The study investigated the effect of methanol extract and its fractionations obtained from Yemeni khat on the smooth muscle isometric tension in Lewis rat aortal ring preparations and compared the effects of the crimson and green leaves. Khat leaves were sorted into green (khat Light; KL) and crimson (khat Dark; KD) leaves, extracted with methanol, followed with solvent-solvent extraction (benzene, chloroform and ethylacetate). The contractile activity of the fractions was tested using aortal ring preparations. The control (phenylepherine contraction) methanol extracts contracted aortas at concentrations 250, 125 and 67.5 microg/ml buffer by 80.2%, 57.3%, 26.4% and 81.5%, 65.6%, 24.6% for KL and KD, respectively. Fractions of benzene (BF) and ethylacetate (EaF) contracted the aorta with 2 microgm, whereas, chloroform (ChF) with 1 microgm/1 ml buffer was less potent. The shape of contraction curve produced by EaF differed from that of ChF and BF of both (KL and KD). The EaF induced-contraction peaked after 3.3 +/- 0.94 mins, whereas those of BF and CHF peaked after 18.0 +/- 2.2, 19.7 +/- 0.94 mins, respectively. Pre-incubation with nifedipine (10(-6) M) insignificantly reduced the contraction induced by all fractionations, but prazosin (10(-6) M) reduced the contraction by 81.9%, 63.1%, 71.8% with p = 0.23, 0.09, 0.15 for BF, ChF and EaF of KL, respectively. It significantly reduced contraction of ChF, 64.1%; p = 0.02, and of EaF, 73.5%; p = 0.04 of KD, while the reduction in contraction of BF was 63.1%; p = 0.06. In conclusion, fractions of green and crimson Yemeni khat leaves contracted aortas of Lewis rats. Both leaves behave almost similarly. Contraction induced by chloroform fraction produced alpha-sympathetic activity.
Yang, Bin; Wang, Fei; Cao, Huili; Liu, Guifang; Zhang, Yuean; Yan, Ping; Li, Bao
2017-01-01
Caffeoylxanthiazonoside (CYT) is an active constituent isolated from the fruit of the Xanthium strumarium L plant. The aim of the present study was to investigate the cardioprotective effects of oral administration of CYT on chronic heart failure (CHF) and its underlying mechanisms. A rat model of CHF was first established, and cardiac function indices, including the heart/body weight index, left heart/body weight index, fractional shortening (FS), ejection fraction (EF), cardiac output (CO) and heart rate (HR), were subsequently determined by cardiac ultrasound. Serum levels of lactate dehydrogenase (LDH) and creatine kinase (CK), and the levels of pro-inflammatory cytokines, including tumor necrosis factor (TNF)-α, interleukin (IL)-6 and IL-1β in heart tissues and cardiac microvascular endothelial cells (CMECs) were determined using ELISA. In addition, the protein expression levels of nuclear factor-κB (NF-κB) signaling pathway members were determined by western blotting in CMECs. The results demonstrated that oral administration of 10, 20, 40 mg/kg CYT significantly reduced cardiac hypertrophy and reversed FS, EF, CO and HR when compared with CHF model rats. In addition, CYT administration significantly decreased the levels of TNF-α, IL-6 and IL-1β in heart tissues, as well as serum LDH and CK levels. Furthermore, exposure of CMECs to 20, 40 and 80 µg/ml CYT significantly decreased the production of TNF-α, IL-1β and IL-6. The protein expression levels of cytoplasmic NF-κB p65 and IκB were upregulated, while nuclear NF-κB p65 was downregulated following treatment of CMECs with 20, 40 and 80 µg/ml CYT when compared with untreated CHF model controls. In conclusion, the results of the current study suggest that CYT demonstrates cardioprotective effects in CHF model rats by suppressing the expression of pro-inflammatory cytokines and the NF-κB signaling pathway. PMID:29104638
Yang, Bin; Wang, Fei; Cao, Huili; Liu, Guifang; Zhang, Yuean; Yan, Ping; Li, Bao
2017-11-01
Caffeoylxanthiazonoside (CYT) is an active constituent isolated from the fruit of the Xanthium strumarium L plant. The aim of the present study was to investigate the cardioprotective effects of oral administration of CYT on chronic heart failure (CHF) and its underlying mechanisms. A rat model of CHF was first established, and cardiac function indices, including the heart/body weight index, left heart/body weight index, fractional shortening (FS), ejection fraction (EF), cardiac output (CO) and heart rate (HR), were subsequently determined by cardiac ultrasound. Serum levels of lactate dehydrogenase (LDH) and creatine kinase (CK), and the levels of pro-inflammatory cytokines, including tumor necrosis factor (TNF)-α, interleukin (IL)-6 and IL-1β in heart tissues and cardiac microvascular endothelial cells (CMECs) were determined using ELISA. In addition, the protein expression levels of nuclear factor-κB (NF-κB) signaling pathway members were determined by western blotting in CMECs. The results demonstrated that oral administration of 10, 20, 40 mg/kg CYT significantly reduced cardiac hypertrophy and reversed FS, EF, CO and HR when compared with CHF model rats. In addition, CYT administration significantly decreased the levels of TNF-α, IL-6 and IL-1β in heart tissues, as well as serum LDH and CK levels. Furthermore, exposure of CMECs to 20, 40 and 80 µg/ml CYT significantly decreased the production of TNF-α, IL-1β and IL-6. The protein expression levels of cytoplasmic NF-κB p65 and IκB were upregulated, while nuclear NF-κB p65 was downregulated following treatment of CMECs with 20, 40 and 80 µg/ml CYT when compared with untreated CHF model controls. In conclusion, the results of the current study suggest that CYT demonstrates cardioprotective effects in CHF model rats by suppressing the expression of pro-inflammatory cytokines and the NF-κB signaling pathway.
Compostella, Leonida; Nicola, Russo; Tiziana, Setzu; Caterina, Compostella; Fabio, Bellotto
2014-11-01
Cardiac autonomic dysfunction, clinically expressed by reduced heart rate variability (HRV), is present in patients with congestive heart failure (CHF) and is related to the degree of left ventricular dysfunction. In athletes, HRV is an indicator of ability to improve performance. No similar data are available for CHF. The aim of this study was to assess whether HRV could predict the capability of CHF patients to improve physical fitness after a short period of exercise-based cardiac rehabilitation (CR). This was an observational, non-randomized study, conducted on 57 patients with advanced CHF, admitted to a residential cardiac rehabilitation unit 32 ± 22 days after an episode of acute heart failure. Inclusion criteria were sinus rhythm, stable clinical conditions, no diabetes and ejection fraction ≤ 35%. HRV (time-domain) and mean and minimum heart rate (HR) were evaluated using 24-h Holter at admission. Patients' physical fitness was evaluated at admission by 6-minute walking test (6MWT) and reassessed after two weeks of intensive exercise-based CR. Exercise capacity was evaluated by a symptom-limited cardiopulmonary exercise test (CPET). Patients with very depressed HRV (SDNN 55.8 ± 10.0 ms) had no improvement in their walking capacity after short CR, walked shorter absolute distances at final 6MWT (348 ± 118 vs. 470 ± 109 m; P = 0.027) and developed a peak-VO2 at CPET significantly lower than patients with greater HRV parameters (11.4 ± 3.7 vs. an average > 16 ± 4 mL/kg/min). Minimum HR, but not mean HR, showed a negative correlation (ρ = -0.319) with CPET performance. In patients with advanced CHF, depressed HRV and higher minimum HR were predictors of poor working capacity after a short period of exercise-based CR. An individualized and intensive rehabilitative intervention should be considered for these patients.
Canepa, Marco; Straburzynska-Migaj, Ewa; Drozdz, Jaroslaw; Fernandez-Vivancos, Carla; Pinilla, Jose Manuel Garcia; Nyolczas, Noemi; Temporelli, Pier Luigi; Mebazaa, Alexandre; Lainscak, Mitja; Laroche, Cécile; Maggioni, Aldo Pietro; Piepoli, Massimo F; Coats, Andrew J S; Ferrari, Roberto; Tavazzi, Luigi
2018-01-01
To describe the characteristics and assess the 1-year outcomes of hospitalized (HHF) and chronic (CHF) heart failure patients with chronic obstructive pulmonary disease (COPD) enrolled in a large European registry between May 2011 and April 2013. Overall, 1334/6920 (19.3%) HHF patients and 1322/9409 (14.1%) CHF patients were diagnosed with COPD. In both groups, patients with COPD were older, more frequently men, had a worse clinical presentation and a higher prevalence of co-morbidities. In HHF, the increase in the use of heart failure (HF) medications at hospital discharge was greater in non-COPD than in COPD for angiotensin-converting enzyme inhibitors (+13.7% vs. +7.2%), beta-blockers (+20.6% vs. +11.8%) and mineralocorticoid receptor antagonists (+20.9% vs. +17.3%), thus widening the gap in HF treatment already existing between the two groups at admission. In CHF patients, there was a similar increase in the use of these medications after enrollment visit in the two groups, leaving a significant difference of 8.2% for beta-blockers in favour of non-COPD patients (89.8% vs. 81.6%, P < 0.001). At 1-year follow-up, the hazard ratios for COPD in multivariable analysis confirmed its independent association with hospitalizations both in HHF [all-cause: 1.16 (1.04-1.29), for HF: 1.22 (1.05-1.42)] and CHF patients [all-cause: 1.26 (1.13-1.41), for HF: 1.37 (1.17-1.60)]. The association between COPD and all-cause mortality was not confirmed in both groups after adjustments. COPD frequently coexists in HHF and CHF, worsens the clinical course of the disease, and significantly impacts its therapeutic management and prognosis. The matter should deserve greater attention from the cardiology community. © 2017 The Authors. European Journal of Heart Failure © 2017 European Society of Cardiology.
Mpinga, Emmanuel Kabengele; Frey, Conrad; Chastonay, Philippe
2014-01-01
Torture is an important social and political problem worldwide that affects millions of people. Many host countries give victims of torture the status of refugee and take care of them as far as basic needs; health care, professional reinsertion, and education. Little is known about the costs of torture. However, this knowledge could serve as an additional argument for the prevention and social mobilization to fight against torture and to provide a powerful basis of advocacy for rehabilitation programs and judiciary claims. Development of a model for estimating the economic costs of torture and applying the model to a specific country. The estimation of the possible prevalence of victims of torture was based on a review of the literature. The identification of the socioeconomic factors to be considered was done by analogy with various health problems. The estimation of the loss of the productivity and of the economic burden of disease related to torture was done through the human capital approach and the component technique analysis. The model was applied to the situation in Switzerland of estimated torture victims Switzerland is confronted with. When applied to the case study, the direct costs - such as housing, food, and clothing - represent roughly 130 million Swiss francs (CHF) per year; whereas, health care costs amount to 16 million CHF per year, and the costs related to education of young people to 34 million CHF per year. Indirect costs, namely those costs related to the loss of the productivity of direct survivors of torture, have been estimated to one-third of 1 billion CHF per year. This jumps to 10,073,419,200 CHF in the loss of productivity if one would consider 30 years of loss per survivor. Our study shows that a rough estimation of the costs related to torture is possible with some prerequisites, such as access to social and economic indicators at the country level.
Rosenstock, Julio; Marx, Nikolaus; Neubacher, Dietmar; Seck, Thomas; Patel, Sanjay; Woerle, Hans-Juergen; Johansen, Odd Erik
2015-05-21
The cardiovascular (CV) safety of linagliptin was evaluated in subjects with type 2 diabetes (T2DM). Pre-specified patient-level pooled analysis of all available double-blind, randomized, controlled trials, ≥ 12 weeks' duration (19 trials, 9459 subjects) of linagliptin versus placebo/active treatment. Primary end point: composite of prospectively adjudicated CV death, non-fatal myocardial infarction, non-fatal stroke, and hospitalization for unstable angina (4P-MACE). Hospitalization for congestive heart failure (CHF) was also evaluated; adjudication of CHF was introduced during the phase 3 program (8 trials; 3314 subjects). 4P-MACE was assessed in placebo-controlled trials (subgroup of 18 trials; 7746 subjects). Investigator-reported events suggestive of CHF from 24 placebo-controlled trials (including trials <12 weeks' duration, 8778 subjects) were also analyzed. 5847 patients received linagliptin (5 mg: 5687, 10 mg: 160) and 3612 comparator (glimepiride: 775, voglibose: 162, placebo: 2675); cumulative exposure, 4421.3 and 3254.7 patient-years, respectively. 4P-MACE incidence rates: 13.4 per 1000 patient-years, linagliptin (60 events), 18.9, total comparators (62 events); overall hazard ratio (HR), 0.78 (95% confidence interval [CI], 0.55-1.12). HR for adjudicated hospitalization for CHF (n = 21): 1.04 (0.43-2.47). For placebo-controlled trials, 4P-MACE incidence rates: 14.9 per 1000 patient-years, linagliptin (43 events), 16.4, total comparators (29 events); overall HR, 1.09 (95% CI, 0.68-1.75). Occurrence of investigator-reported events suggestive of CHF was low for linagliptin- (26 events, 0.5%; serious: 16 events, 0.3%) and placebo-treated (8 events, 0.2%; serious: 6 events, 0.2%) patients. Linagliptin is not associated with increased CV risk versus pooled active comparators or placebo in patients with T2DM.
Mitrani, Raul D; Sager, Solomon J; Moscucci, Mauro; Cogan, John; Myerburg, Robert J
2014-08-20
Transient variations in physiological parameters may forewarn of life-threatening cardiac events, but are difficult to identify clinically. Implantable cardioverter defibrillators (ICD) designed to measure transthoracic impedance provide a surrogate marker for pulmonary congestion. The aim of this study is to determine if the frequency of changes in transthoracic impedance (TTI) is associated with congestive heart failure (CHF) exacerbation and predicts mortality. We followed 109 consecutive patients (pts) with ICDs (n=58) or CRT-ICDs (n=51) for a mean of 21.3 (+10.2) months. Using 80 ohm-days as a reference, we correlated the frequency of TTI changes above this index to CHF hospitalizations or death. There was at least one TTI threshold crossing in 79 (72%) pts over 23.3 months follow-up, with a mean of 1.8 ± 3.4 per year. There were 18 pts with CHF hospitalizations who had a mean of 4.3 TTI threshold crossings/year (S.D.=±7.3; median=2.8), compared to 1.3 (S.D.=±1.5; median=0.8) among pts without CHF hospitalizations (p=0.0006). Among 20 patients who died during follow-up, there were 4.2 (S.D.=±7.0; median=2.9) TTI threshold crossings/year, compared with 1.3 (S.D.=±1.3; median=0.9) threshold crossings/year among survivors (p=0.0004). Using Cox Proportional Hazard modeling, after adjusting for age, baseline EF, and number of shocks, TTI threshold crossing was an independent predictor of death (HR 1.72, 95% CI 1.26-2.36, p=0.001). Increased frequency of TTI threshold crossings may be a useful predictor of transient risk for identifying a subgroup of ICD recipients at greater individual risk for death or CHF hospitalizations. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.
Fröhlich, Hanna; Raman, Nandita; Täger, Tobias; Schellberg, Dieter; Goode, Kevin M; Kazmi, Syed; Grundtvig, Morten; Hole, Torstein; Cleland, John G F; Katus, Hugo A; Agewall, Stefan; Clark, Andrew L; Atar, Dan; Frankenstein, Lutz
2017-07-01
In patients with chronic heart failure (CHF) increasing levels of total serum cholesterol are associated with improved survival - while statin usage is not. The impact of statin treatment on the "reverse epidemiology" of cholesterol is unclear. 2992 consecutive patients with non-ischemic CHF due to left ventricular systolic dysfunction from the Norwegian CHF Registry and the CHF Registries of the Universities of Hull, UK, and Heidelberg, Germany, were studied. 1736 patients were individually double-matched on both cholesterol levels and the individual propensity scores for statin treatment. All-cause mortality was analyzed as a function of baseline cholesterol and statin use in both the general and the matched sample. 1209 patients (40.4%) received a statin. During a follow-up of 13,740 patient-years, 360 statin users (29.8%) and 573 (32.1%) statin non-users died. When grouped according to total cholesterol levels as low (≤3.6mmol/L), moderate (3.7-4.9mmol/L), high (4.8-6.2mmol/L), and very high (>6.2mmol/L), we found improved survival with very high as compared with low cholesterol levels. This association was present in statin users and non-users in both the general and matched sample (p<0.05 for each group comparison). The negative association of total cholesterol and mortality persisted when cholesterol was treated as a continuous variable (HR 0.83, 95%CI 0.77-0.90, p<0.001 for matched patients), but it was less pronounced in statin users than in non-users (F-test p<0.001). Statins attenuate but do not eliminate the reverse epidemiological association between increasing total serum cholesterol and improved survival in patients with non-ischemic CHF. Copyright © 2017 Elsevier B.V. All rights reserved.
Schmalgemeier, Heidi; Bitter, Thomas; Fischbach, Thomas; Horstkotte, Dieter; Oldenburg, Olaf
2014-01-01
Manifestation of central sleep apnea (CSA) with Cheyne-Stokes respiration is of major prognostic impact in chronic heart failure (CHF). Inflammatory processes have been linked to a progression of cardiovascular diseases, including heart failure. While an association of C-reactive protein (CRP) levels to obstructive sleep apnea has been documented before, there is a lack of information regarding variation of CRP levels in patients with CSA. The objective of this study was to investigate a potential association of CRP levels to CSA severity in CHF patients. High sensitivity CRP levels were analyzed in 966 patients with CHF (BMI 26.3 ± 4.6, New York Heart Association class 2.6 ± 0.5, left ventricular ejection fraction 29.4 ± 7.9%, N-terminal pro-brain natriuretic peptide, NT-proBNP, level 2,209 ± 3,315 pg/ml) without sleep-disordered breathing (SDB; Apnea-Hypopnea Index, AHI, <5/h) or various degrees of CSA, documented by in-hospital cardiorespiratory polygraphy or polysomnography. The CRP concentration in CHF patients was 0.550 ± 0.794 mg/dl in patients without SDB (AHI 0-4/h, n = 403) versus 0.488 ± 0.708 mg/dl in patients with mild CSA (AHI 5-14/h, n = 123, p = n.s.) and 0.660 ± 0.963 mg/dl in patients with moderate CSA (AHI 15-29/h, n = 160, p = n.s.). In patients with severe CSA (AHI ≥ 30/h, n = 280), significantly higher CRP concentrations were documented (0.893 ± 1.384 mg/dl, p < 0.05). Stepwise regression analysis revealed AHI, NT-proBNP and heart rate to be independently associated with elevated CRP levels. Severe CSA in CHF patients is associated with elevated levels of CRP, a systemic marker of inflammation and cardiovascular risk. This might explain in part the negative prognostic impact of CSA in these patients. Copyright © 2013 S. Karger AG, Basel.
Sane, Rohit; Aklujkar, Abhijeet; Patil, Atul; Mandole, Rahul
The present study was designed to evaluate effect of heart failure reversal therapy (HFRT) using herbal procedure (panchakarma) and allied therapies, as add-on to standard CHF treatment (SCT) in chronic heart failure (CHF) patients. This open-label, randomized study conducted in CHF patients (aged: 25-65 years, ejection fraction: 30-65%), had 3-phases: 1-week screening, 6-week treatment (randomized [1:1] to HFRT+SCT or SCT-alone) and follow-up (12-week). Twice weekly HFRT (60-75min) consisting of snehana (external oleation), swedana (passive heat therapy), hrudaydhara (concoction dripping treatment) and basti (enema) was administered. Primary endpoints included evaluation of change in metabolic equivalents of task (MET) and peak oxygen uptake (VO 2peak ) from baseline, at end of 6-week treatment and follow-up at week-18 (non-parametric rank ANCOVA analysis). Safety and quality of life (QoL) was assessed. Seventy CHF patients (n=35, each treatment-arm; mean [SD] age: 53.0 [8.6], 80% men) were enrolled in the study. All patients completed treatment phase. Add-on HFRT caused a significant increase in METs (least square mean difference [LSMD], 6-week: 1.536, p=0.0002; 18-week: -1.254, p=0.0089) and VO 2peak (LSMD, 6-week: -5.52, p=0.0002; 18-week: -4.517, p=0.0089) as compared with SCT-alone. Results were suggestive of improved functional capacity in patients with HFRT (QoL; Mean [SD] HFRT+SCT vs. SCT-alone; 6-week: -0.44 [0.34] vs. -0.06 [0.25], p<0.0001 and 18-week: -0.53 [0.35] vs. -0.29 [0.26], p=0.0013). Seven treatment-emergent adverse events (mild severity) were reported in HFRT-arm. Findings of this study highlight therapeutic efficacy of add-on HFRT vs. SCT-alone in CHF patients. The non-invasive HFRT showed no safety concerns. Copyright © 2016. Published by Elsevier B.V.
Perraudin, Clemence; Bourdin, Aline; Spertini, Francois; Berger, Jérôme; Bugnon, Olivier
2016-07-01
Home-based subcutaneous immunoglobulin (SCIg) therapy is an alternative to hospital-based intravenous infusions (IVIg). However, SCIg requires patient training and long-term support to ensure proper adherence, optimal efficacy and safety. We evaluated if switching patients to home-based SCIg including an interprofessional drug therapy management program (physician, community pharmacist and nurse) would be cost-effective within the Swiss healthcare system. A 3-year cost-minimization analysis was performed from a societal perspective comparing monthly IVIg in an outpatient clinic and home-based weekly SCIg including an interprofessional program. Healthcare costs (immunoglobulin, professional time, infusion pump and disposables) were derived from administrative data. Transportation and productivity loss were estimated by expert opinion. The results were expressed in Swiss francs (CHF) and converted to Euros and US dollars (1 CHF = 0.92€, 1 CHF = $1.02; www.xe.com , 12/14/2015). Under base case assumptions, SCIg was estimated to cost 35,862 CHF (33,134€; $36,595) per patient during the first year and 30,309 CHF (28,004€; $30,929) in subsequent years versus 35,370 CHF (32,679€; $36,095) per year for IVIg. The total savings from switching to SCIg with the interprofessional program were 9630 CHF (8897€; $9828) per patient over 3 years. The results were relatively sensitive to the cost per gram of IgG, the cost of equipment and the annual number of infusions. Home-based SCIg including an interprofessional therapy management program may be an efficient alternative for patients. The program provides long-term support from self-administration training to the responsible use of therapy (proper adherence, optimal efficacy and safety). Over the short term, additional costs from purchasing equipment and the drug therapy management program were offset by avoiding hospital costs.
Farag, Mohamed; Mabote, Thato; Shoaib, Ahmad; Zhang, Jufen; Nabhan, Ashraf F; Clark, Andrew L; Cleland, John G
2015-10-01
Hydralazine (H) and nitrates (Ns), when combined, reduced morbidity and mortality in some trials of chronic heart failure (CHF). It is unclear whether either agent used alone provides similar benefits. We aimed to evaluate the effects of H and/or N in patients with CHF. A systematic review of randomised trials assessing the effects of H and N in CHF. For meta-analysis, only the endpoints of all-cause mortality and cardiovascular mortality were considered. In seven trials evaluating H&N in 2626 patients, combination therapy reduced all-cause mortality (OR 0.72; 95% CI 0.55-0.95; p=0.02), and cardiovascular mortality (OR 0.75; 95% CI 0.57-0.99; p=0.04) compared to placebo. However, when compared to angiotensin converting enzyme inhibitors (ACEIs), combination therapy was associated with higher all-cause mortality (OR 1.35; 95% CI 1.03-1.76; p=0.03), and cardiovascular mortality (OR 1.37; 95% CI 1.04-1.81; p=0.03). For N alone, ten trials including 375 patients reported all-cause mortality and showed a trend to harm (13 deaths in those assigned to nitrates and 7 to placebo; OR 2.13; 95% CI 0.88-5.13; p=0.09). For H alone, three trials showed no difference in all-cause mortality compared to placebo (OR 0.96; 95% CI 0.37-2.47; p=0.93), and two trials suggested inferiority to ACEI (OR 2.28; 95% CI 1.03-5.04; p=0.04). Compared to placebo, H&N reduces mortality in patients with CHF. Whether race or background therapy influences benefit is uncertain, but on direct comparison H&N appears inferior to ACEI. There is little evidence to support the use of either drug alone in CHF. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
Kou, Seisyou; Suzuki, Kengo; Akashi, Yoshihiro J; Mizukoshi, Kei; Takai, Manabu; Izumo, Masaki; Shimozato, Takashi; Hayashi, Akio; Ohtaki, Eiji; Osada, Naohiko; Omiya, Kazuto; Nobuoka, Sachihiko; Miyake, Fumihiko
2011-06-01
Left ventricular ejection fraction (LVEF) predicts mortality in patients with chronic heart failure (CHF). However, a weak correlation was found between LVEF and peak oxygen uptake ([Formula: see text]) in CHF patients. Global longitudinal strain measured by two-dimensional (2D) strain is regarded as a more useful predictor of cardiac events than LVEF. We investigated whether 2D strain obtained at rest could predict peak [Formula: see text] in patients with CHF. Fifty-one patients (mean age of 54.0 ± 12.0 years, 14 females, LVEF 46.0 ± 15.0%) with stable CHF underwent resting echocardiography and cardiopulmonary exercise testing. Leg muscle strength was measured for the evaluation of peripheral factors. Global longitudinal strain (GLS) in the apical 4-, 3-, and 2-chamber views and global circumferential strain (GCS) in the parasternal mid short-axis view were measured. In all patients, peak [Formula: see text] correlated with leg muscle strength (r = 0.55, p < 0.0001), LVEF (r = 0.46, p < 0.001), GLS (r = -0.45, p < 0.001), and GCS (r = -0.41, p = 0.005), respectively. No significant correlation was found between the ratio of early transmitral velocity to peak early diastolic mitral annulus velocity (E/E') and peak [Formula: see text]. In the patients with heart failure and reduced LVEF, a multiple stepwise linear regression analysis based on leg muscle strength, LVEF, E/E', GLS, and GCS was performed to identify independent predictors of peak [Formula: see text], resulting in leg muscle strength and GLS (R (2) = 0.888) as independent predictors of peak [Formula: see text]. Global longitudinal strain at rest could possibly predict exercise capacity, which appeared to be more useful than LVEF, E/E', and GCS in CHF patients with reduced LVEF.
de Andrade, James N B M; Christopher Orton, E; Boon, June; Nishimori, Celina T D; Olivaes, Claudio; Camacho, Aparecido A
2011-09-01
To report the outcome of partial external mitral annuloplasty in dogs with congestive heart failure (CHF) due to mitral regurgitation caused by myxomatous mitral valve degeneration (MMVD). Nine client-owned dogs with CHF due to mitral regurgitation caused by MMVD. Surgery consisted of a double row of pledget-butressed continuous suture lines placed into the left ventricle parallel and just ventral to the atrioventricular groove between the subsinuosal branch of the left circumflex coronary artery and the paraconal branch of the left coronary artery. Two dogs died during surgery because of severe hemorrhage. Two dogs died 12 and 36 h after surgery because of acute myocardial infarction. Three dogs were euthanized 2 and 4 weeks after surgery because of progression of CHF, 1 was euthanized 30 days after surgery for non-cardiac disease, and 1 survived for 48 months. In the 5 dogs that survived to discharge there was no significant change in the left atrium to aortic ratio with surgery (3.6 ± 0.56 before surgery; 3.1 ± 0.4 after surgery; p = 0.182), and no significant change in mitral regurgitant fraction in 4 dogs in which this measurement was made (78.7 ± 2.0% before surgery; 68.7 ± 7.5% after surgery; p = 0.09). Partial external mitral annuloplasty in dogs with CHF due to MMVD was associated with high perioperative mortality and most dogs that survived to discharge failed to show clinically relevant palliation from this procedure. Consequently, partial external mitral annuloplasty is not a viable option for dogs with mitral regurgitation due to MMVD that has progressed to the stage of CHF. Copyright © 2011 Elsevier B.V. All rights reserved.
Krähenbühl, Jean-Marc; Decollogny, Anne; Bugnon, Olivier
2008-12-01
To measure the positive predictive value (PPV) of the cost of drug therapy (threshold = 2000 Swiss francs [CHF], US$1440,
The T.O.S.CA. Project: research, education and care.
Bossone, Eduardo; Limongelli, Giuseppe; Malizia, Graziella; Ferrara, Francesco; Vriz, Olga; Citro, Rodolfo; Marra, Alberto Maria; Arcopinto, Michele; Bobbio, Emanuele; Sirico, Domenico; Caliendo, Luigi; Ballotta, Andrea; D'Andrea, Antonello; Frigiola, Alessandro; Isgaard, Jorgen; Saccà, Luigi; Antonio, Cittadini
2011-12-01
Despite recent and exponential improvements in diagnostic-therapeutic pathways, an existing "GAP" has been revealed between the "real world care" and the "optimal care" of patients with chronic heart failure (CHF). We present the T.O.S.CA. Project (Trattamento Ormonale dello Scompenso CArdiaco), an Italian multicenter initiative involving different health care professionals and services aiming to explore the CHF "metabolic pathophysiological model" and to improve the quality of care of HF patients through research and continuing medical education.
2011-04-28
communities are unable to contribute materials and services useful to technical infrastructure projects. CHF also reported that 867,070 Iraqis directly...may be in-kind, rather than cash, and can include donated materials and supplies, equipment and services, land and property, and volunteer time and...electrical materials N/A N/Ab 75,000 11 – Provide a water pump and transformer 143,145 3,550 68,740 Total $383,835 $934,744 $1,014,041 Notes: a
Steady State Film Boiling Heat Transfer Simulated With Trace V4.160
DOE Office of Scientific and Technical Information (OSTI.GOV)
Audrius Jasiulevicius; Rafael Macian-Juan
2006-07-01
This paper presents the results of the assessment and analysis of TRACE v4.160 heat transfer predictions in the post-CHF (critical heat flux) region and discusses the possibilities to improve the TRACE v4.160 code predictions in the film boiling heat transfer when applying different film boiling correlations. For this purpose, the TRACE v4.160-calculated film boiling heat flux and the resulting maximum inner wall temperatures during film boiling in single tubes were compared with experimental data obtained at the Royal Institute of Technology (KTH) in Stockholm, Sweden. The experimental database included measurements for pressures ranging from 30 to 200 bar and coolantmore » mass fluxes from 500 to 3000 kg/m{sup 2}s. It was found that TRACE v4.160 does not produce correct predictions of the film boiling heat flux, and consequently of the maximum inner wall temperature in the test section, under the wide range of conditions documented in the KTH experiments. In particular, it was found that the standard TRACE v4.160 under-predicts the film boiling heat transfer coefficient at low pressure-low mass flux and high pressure-high mass flux conditions. For most of the rest of the investigated range of parameters, TRACE v4.160 over-predicts the film boiling heat transfer coefficient, which can lead to non-conservative predictions in applications to nuclear power plant analyses. Since no satisfactory agreement with the experimental database was obtained with the standard TRACE v4.160 film boiling heat transfer correlations, we have added seven film boiling correlations to TRACE v4.160 in order to investigate the possibility to improve the code predictions for the conditions similar to the KTH tests. The film boiling correlations were selected among the most commonly used film boiling correlations found in the open literature, namely Groeneveld 5.7, Bishop (2 correlations), Tong, Konkov, Miropolskii and Groeneveld-Delorme correlations. The only correlation among the investigated, which resulted in a significant improvement of TRACE predictions, was the Groeneveld 5.7. It was found, that replacing the current film boiling correlation (Dougall-Rohsenow) for the wall-togas heat transfer with Groeneveld 5.7 improves the code predictions for the film boiling heat transfer at high qualities in single tubes in the entire range of pressure and coolant mass flux considered. (authors)« less
Size effects in non-linear heat conduction with flux-limited behaviors
NASA Astrophysics Data System (ADS)
Li, Shu-Nan; Cao, Bing-Yang
2017-11-01
Size effects are discussed for several non-linear heat conduction models with flux-limited behaviors, including the phonon hydrodynamic, Lagrange multiplier, hierarchy moment, nonlinear phonon hydrodynamic, tempered diffusion, thermon gas and generalized nonlinear models. For the phonon hydrodynamic, Lagrange multiplier and tempered diffusion models, heat flux will not exist in problems with sufficiently small scale. The existence of heat flux needs the sizes of heat conduction larger than their corresponding critical sizes, which are determined by the physical properties and boundary temperatures. The critical sizes can be regarded as the theoretical limits of the applicable ranges for these non-linear heat conduction models with flux-limited behaviors. For sufficiently small scale heat conduction, the phonon hydrodynamic and Lagrange multiplier models can also predict the theoretical possibility of violating the second law and multiplicity. Comparisons are also made between these non-Fourier models and non-linear Fourier heat conduction in the type of fast diffusion, which can also predict flux-limited behaviors.
Sadikaj, Gentiana; Moskowitz, D S; Zuroff, David C
2015-08-01
High intrapersonal variability has frequently been found to be related to poor personal and interpersonal outcomes. Little research has examined processes by which intrapersonal variability influences outcomes. This study explored the relation of intrapersonal variability in negative affect (negative affect flux) to accuracy and bias in the perception of a romantic partner's quarrelsome behavior. A sample of 93 cohabiting couples participated in a study using an event-contingent recording (ECR) methodology in which they reported their negative affect, quarrelsome behavior, and perception of their partner's quarrelsome behavior in interactions with each other during a 20-day period. Negative affect flux was operationalized as the within-person standard deviation of negative affect scores across couple interactions. Findings suggested that participants were both accurate in tracking changes in their partner's quarrelsome behavior and biased in assuming their partner's quarrelsome behavior mirrored their own quarrelsome behavior. Negative affect flux moderated both accuracy and bias of assumed similarity such that participants with higher flux manifested both greater tracking accuracy and larger bias of assumed similarity. Negative affect flux may be related to enhanced vigilance to close others' negative behavior, which may explain higher tracking accuracy and propensity to rely on a person's own negative behavior as a means of judging others' negative behavior. These processes may augment these individuals' negative interpersonal behavior, enhance cycles of negative social interactions, and lead to poor intrapersonal and interpersonal outcomes.
An economic model to evaluate the mitigation programme for bovine viral diarrhoea in Switzerland.
Häsler, B; Howe, K S; Presi, P; Stärk, K D C
2012-09-15
Economic analyses are indispensable as sources of information to help policy makers make decisions about mitigation resource use. The aim of this study was to conduct an economic evaluation of the Swiss national mitigation programme for bovine viral diarrhoea virus (BVDV), which was implemented in 2008 and concludes in 2017. The eradication phase of the mitigation programme comprised testing and slaughtering of all persistently infected (PI) animals found. First, the whole population was antigen tested and all PI cattle removed. Since October 2008, all newborn calves have been subject to antigen testing to identify and slaughter PI calves. All mothers of PI calves were retested and slaughtered if the test was positive. Antigen testing in calves and elimination of virus-carriers was envisaged to be conducted until the end of 2011. Subsequently, a surveillance programme will document disease freedom or detect disease if it recurs. Four alternative surveillance strategies based on antibody testing in blood from newborn calves and/or milk from primiparous cows were proposed by Federal Veterinary Office servants in charge of the BVDV mitigation programme. A simple economic spreadsheet model was developed to estimate and compare the costs and benefits of the BVDV mitigation programme. In an independent project, the impact of the mitigation programme on the disease dynamics in the population was simulated using a stochastic compartment model. Mitigation costs accrued from materials, labour, and processes such as handling and testing samples, and recording results. Benefits were disease costs avoided by having the mitigation programme in place compared to a baseline of endemic disease equilibrium. Cumulative eradication costs and benefits were estimated to determine the break-even point for the eradication component of the programme. The margin over eradication cost therefore equalled the maximum expenditure potentially available for surveillance without the net benefit from the mitigation programme overall becoming zero. Costs of the four surveillance strategies and the net benefit of the mitigation programme were estimated. Simulations were run for the years 2008-2017 with 20,000 iterations in @Risk for Excel. The mean baseline disease costs were estimated to be 16.04 m CHF (1 Swiss Franc, CHF=0.73 € at the time of analysis) (90% central range, CR: 14.71-17.39 m CHF) in 2008 and 14.89 m CHF (90% CR: 13.72-16.08 m CHF) in 2009. The break-even point was estimated to be reached in 2012 and the margin over eradication cost 63.15m CHF (90% CR: 53.72-72.82 m CHF). The discounted cost for each surveillance strategy was found to be smaller than the margin, so the mitigation programme overall is expected to have a positive net economic benefit irrespective of the strategy adopted. For economic efficiency, the least cost surveillance alternative must be selected. Copyright © 2012 Elsevier B.V. All rights reserved.
Influence of Oxygen on Cu Distribution Behavior Between Molten Iron and FeS-Based Flux
NASA Astrophysics Data System (ADS)
Kang, Youngjo; Shin, Kil-Sun; Morita, Kazuki
2018-06-01
Cu distribution behavior between molten iron and a sulfide flux was investigated under different oxygen contents in the sulfide flux to clarify the effect of oxygen content in FeS-based flux on Cu removal. The activity coefficient of CuS0.5 could be experimentally estimated according to the oxygen content. Based on the present result, the possibility of Cu removal by sulfide flux containing a certain amount of oxide was discussed.
Tuzun, Egemen; Bick, Roger; Kadipasaoglu, Cihan; Conger, Jeffrey L.; Poindexter, Brian J.; Gregoric, Igor D.; Frazier, O. H.; Towbin, Jeffrey A.; Radovancevic, Branislav
2011-01-01
Purpose. To provide an ovine model of ventricular remodeling and reverse remodeling by creating congestive heart failure (CHF) and then treating it by implanting a left ventricular assist device (LVAD). Methods. We induced volume-overload heart failure in 2 sheep; 20 weeks later, we implanted an LVAD and assessed recovery 11 weeks thereafter. We examined changes in histologic and hemodynamic data and levels of cellular markers of CHF. Results. After CHF induction, we found increases in LV end-diastolic pressure, LV systolic and diastolic dimensions, wall thickness, left atrial diameter, and atrial natriuretic protein (ANP) and endothelin-1 (ET-1) levels; β-adrenergic receptor (BAR) and dystrophin expression decreased markedly. Biopsies confirmed LV remodeling. After LVAD support, LV systolic and diastolic dimensions, wall thickness, and mass, and ANP and ET-1 levels decreased. Histopathologic and hemodynamic markers improved, and BAR and dystrophin expression normalized. Conclusions. We describe a successful sheep model for ventricular and reverse remodeling. PMID:22347659
NASA Astrophysics Data System (ADS)
Shahzad, Syed Jawad Hussain; Hernandez, Jose Areola; Hanif, Waqas; Kayani, Ghulam Mujtaba
2018-09-01
We investigate the dynamics of efficiency and long memory, and the impact of trading volume on the efficiency of returns and volatilities of four major traded currencies, namely, the EUR, GBP, CHF and JPY. We do so by implementing full sample and rolling window multifractal detrended fluctuation analysis (MF-DFA) and a quantile-on-quantile (QQ) approach. This paper sheds new light by employing high frequency (5-min interval) data spanning from Jan 1, 2007 to Dec 31, 2016. Realized volatilities are estimated using Andersen et al.'s (2001) measure, while the QQ method employed is drawn from Sim and Zhou (2015). We find evidence of higher efficiency levels in the JPY and CHF currency markets. The impact of trading volume on efficiency is only significant for the JPY and CHF currencies. The GBP currency appears to be the least efficient, followed by the EUR. Implications of the results are discussed.
Clarke, Malcolm; Shah, Anila; Sharma, Urvashi
2011-01-01
We conducted a systematic review of large, well-conducted randomised trials designed to evaluate the effectiveness of telemonitoring on patients with congestive heart failure (CHF). Two people reviewed 125 articles independently and selected 13 articles for final review. These studies concerned 3480 patients. The follow-up period of the studies was 3-15 months. Pooled estimate results showed that there was an overall reduction in all-cause mortality (P = 0.02). There was no overall reduction in all-cause hospital admission (P = 0.84), although there was a reduction in CHF hospital admission (P = 0.0004). There was no reduction in all-cause emergency admission (P = 0.67). There was no significant difference in length of stay in hospital, medication adherence or cost. Telemonitoring in conjunction with nurse home visiting and specialist unit support can be effective in the clinical management of patients with CHF and help to improve their quality of life.
Lalukota, Krishna; Cleland, John G F; Ingle, Lee; Clark, Andrew L; Coletta, Alison P
2004-12-01
This article summarises key presentations relevant to the pathophysiology, prevention or treatment of heart failure, from the Heart Failure Society of America annual meeting held in Toronto, Canada. Data from the EnoxiMone in intravenous inOTropE-dependent subjects (EMOTE) study suggest that the oral PDE-3 inhibitor enoximone may be effective for weaning severe heart failure patients from intravenous inotropic therapy. Hawthorn Extract Randomised Blinded Trial in CHF (HERB-CHF) failed to show a benefit of hawthorn extract added to conventional heart failure therapy. A genetic sub-group analysis of the Blocker Evaluation of Survival Trial (BEST) study showed that bucindolol reduced mortality and hospitalisations in patients who were homozygous for the Arg389 variant of the beta(1) adrenoceptor. In the Resynchronisation Hemodynamic Treatment for Heart Failure Management (RHYTHM-ICD) study, patients randomised to cardiac resynchronisation therapy (CRT) showed an improvement in symptoms and functional capacity compared to the control group.
Fluctuations of healthy and unhealthy heartbeat intervals
NASA Astrophysics Data System (ADS)
Lan, Boon Leong; Toda, Mikito
2013-04-01
We show that the RR-interval fluctuations, defined as the difference between successive natural-logarithm of the RR interval, for healthy, congestive-heart-failure (CHF) and atrial-fibrillation (AF) subjects are well modeled by non-Gaussian stable distributions. Our results suggest that healthy or unhealthy RR-interval fluctuation can generally be modeled as a sum of a large number of independent physiological effects which are identically distributed with infinite variance. Furthermore, we show for the first time that one indicator —the scale parameter of the stable distribution— is sufficient to robustly distinguish the three groups of subjects. The scale parameters for healthy subjects are smaller than those for AF subjects but larger than those for CHF subjects —this ordering suggests that the scale parameter could be used to objectively quantify the severity of CHF and AF over time and also serve as an early warning signal for a healthy person when it approaches either boundary of the healthy range.
RELAP5 Application to Accident Analysis of the NIST Research Reactor
DOE Office of Scientific and Technical Information (OSTI.GOV)
Baek, J.; Cuadra Gascon, A.; Cheng, L.Y.
Detailed safety analyses have been performed for the 20 MW D{sub 2}O moderated research reactor (NBSR) at the National Institute of Standards and Technology (NIST). The time-dependent analysis of the primary system is determined with a RELAP5 transient analysis model that includes the reactor vessel, the pump, heat exchanger, fuel element geometry, and flow channels for both the six inner and twenty-four outer fuel elements. A post-processing of the simulation results has been conducted to evaluate minimum critical heat flux ratio (CHFR) using the Sudo-Kaminaga correlation. Evaluations are performed for the following accidents: (1) the control rod withdrawal startup accidentmore » and (2) the maximum reactivity insertion accident. In both cases the RELAP5 results indicate that there is adequate margin to CHF and no damage to the fuel will occur because of sufficient coolant flow through the fuel channels and the negative scram reactivity insertion.« less
Buja, Alessandra; Solinas, Giuliana; Visca, Modesta; Federico, Bruno; Gini, Rosa; Baldo, Vincenzo; Francesconi, Paolo; Sartor, Gino; Bellentani, Mariadonata; Damiani, Gianfranco
2016-01-01
Interest in chronic conditions reflects their role as the first cause of death and disability in developed countries; improving the management of these conditions is a priority for health care services. The aim of this study was to establish which sociodemographic factors influence adherence to standards of care for chronic heart failure (CHF). A generalized multilevel structural equation model was developed and applied to a sample of patients with CHF obtained from administrative data flows in six Italian regions to ascertain any associations between adherence to standards of care for CHF and sociodemographic variables. Indicators of compliance were adherence to beta-blocker therapy (BB-A) and Angiotensin Convertin Enzime inhibitor/Angiotensin Receptor Blocker therapy (ACE-A), and creatinine and electrolyte testing (CNK-T). All indicators were computed over a one-year follow-up. Among a cohort of 24,997 patients, the BB-A rate was 40.4%, the ACE-A rate 61.1%, and the CNK-T rate 57.0%. Factors found associated with adherence were gender, age, and citizenship. Our study shows an inadequate adherence to standards of care for CHF, particularly associated with certain sociodemographic characteristics. This suggests the need to improve the role of primary care in managing this chronic condition. The measures considered only apply to patients with a reduced Left Ventricular Ejection Fraction, hence a limitation of this analysis is the lack of information on left ventricular ejection. PMID:26907316
The physiological basis of rehabilitation in chronic heart and lung disease.
Vogiatzis, Ioannis; Zakynthinos, Spyros
2013-07-01
Cardiopulmonary rehabilitation is recognized as a core component of management of individuals with congestive heart failure (CHF) or chronic obstructive pulmonary disease (COPD) that is designed to improve their physical and psychosocial condition without impacting on the primary organ impairment. This has lead the scientific community increasingly to believe that the main effects of cardiopulmonary rehabilitative exercise training are focused on skeletal muscles that are regarded as dysfunctional in both CHF and COPD. Accordingly, following completion of a cardiopulmonary rehabilitative exercise training program there are important peripheral muscular adaptations in both disease entities, namely increased capillary density, blood flow, mitochondrial volume density, fiber size, distribution of slow twitch fibers, and decreased lactic acidosis and vascular resistance. Decreased lactic acidosis at a given level of submaximal exercise not only offsets the occurrence of peripheral muscle fatigue, leading to muscle task failure and muscle discomfort, but also concurrently mitigates the additional burden on the respiratory muscles caused by the increased respiratory drive, thereby reducing dyspnea sensations. Furthermore in patients with COPD, exercise training reduces the degree of dynamic lung hyperinflation leading to improved arterial oxygen content and central hemodynamic responses, thus increasing systemic muscle oxygen availability. In patients with CHF, exercise training has beneficial direct and reflex sympathoinhibitory effects and favorable effects on normalization of neurohumoral excitation. These physiological benefits apply to all COPD and CHF patients independently of the degree of disease severity and are associated with improved exercise tolerance, functional capacity, and quality of life.
Effects of Age and Heart Failure on Human Cardiac Stem Cell Function
Cesselli, Daniela; Beltrami, Antonio P.; D'Aurizio, Federica; Marcon, Patrizia; Bergamin, Natascha; Toffoletto, Barbara; Pandolfi, Maura; Puppato, Elisa; Marino, Laura; Signore, Sergio; Livi, Ugolino; Verardo, Roberto; Piazza, Silvano; Marchionni, Luigi; Fiorini, Claudia; Schneider, Claudio; Hosoda, Toru; Rota, Marcello; Kajstura, Jan; Anversa, Piero; Beltrami, Carlo A.; Leri, Annarosa
2011-01-01
Currently, it is unknown whether defects in stem cell growth and differentiation contribute to myocardial aging and chronic heart failure (CHF), and whether a compartment of functional human cardiac stem cells (hCSCs) persists in the decompensated heart. To determine whether aging and CHF are critical determinants of the loss in growth reserve of the heart, the properties of hCSCs were evaluated in 18 control and 23 explanted hearts. Age and CHF showed a progressive decrease in functionally competent hCSCs. Chronological age was a major predictor of five biomarkers of hCSC senescence: telomeric shortening, attenuated telomerase activity, telomere dysfunction-induced foci, and p21Cip1 and p16INK4a expression. CHF had similar consequences for hCSCs, suggesting that defects in the balance between cardiomyocyte mass and the pool of nonsenescent hCSCs may condition the evolution of the decompensated myopathy. A correlation was found previously between telomere length in circulating bone marrow cells and cardiovascular diseases, but that analysis was restricted to average telomere length in a cell population, neglecting the fact that telomere attrition does not occur uniformly in all cells. The present study provides the first demonstration that dysfunctional telomeres in hCSCs are biomarkers of aging and heart failure. The biomarkers of cellular senescence identified here can be used to define the birth date of hCSCs and to sort young cells with potential therapeutic efficacy. PMID:21703415