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Sample records for cardiac electrical remodeling

  1. Bcl10 mediates angiotensin II-induced cardiac damage and electrical remodeling.

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    Markó, Lajos; Henke, Norbert; Park, Joon-Keun; Spallek, Bastian; Qadri, Fatimunnisa; Balogh, András; Apel, Ingrid J; Oravecz-Wilson, Katherine I; Choi, Mira; Przybyl, Lukasz; Binger, Katrina J; Haase, Nadine; Wilck, Nicola; Heuser, Arnd; Fokuhl, Verena; Ruland, Jürgen; Lucas, Peter C; McAllister-Lucas, Linda M; Luft, Friedrich C; Dechend, Ralf; Müller, Dominik N

    2014-11-01

    Angiotensin (Ang) II is a potent mediator of both hypertension and cardiac damage; however, the mechanisms by which this occur remain unclear. B-cell lymphoma/leukemia 10 (Bcl10) is a member of the CBM signalosome, which links Ang II and nuclear factor-κB signaling. We hypothesized that Bcl10 is pivotal in the pathogenesis of Ang II-induced cardiac damage. Ang II infusion in mice lacking Bcl10 resulted in reduced cardiac fibrosis, less cellular infiltration, and improved arrhythmogenic electric remodeling, despite a similar degree of hypertension or cardiac hypertrophy. Adoptive transfer of bone marrow (BM), whereby Bcl10 knockout or wildtype BM was transferred to their opposite genotype recipients, revealed the dual importance of Bcl10 within both cardiac and immune cells. Loss of Bcl10 in cardiac cells resulted in reduced expression of genes important for the adhesion and recruitment of immune cells. In vitro experiments demonstrated that adhesion of monocytes to Ang II-treated endothelial cells also required Bcl10. Additionally, Bcl10 deficiency in macrophages reduced their intrinsic migratory ability. To address the role of BM-derived fibroblasts in the formation of cardiac fibrosis, we explored whether Bcl10 is also important for the infiltration of BM-derived (myo)fibroblasts into the heart. The transfer of green fluorescent protein positive wildtype BM into Bcl10 knockout recipient mice revealed a reduced number of noncardiac (myo)fibroblasts compared with those wildtype recipients. Our results demonstrate the significant role of Bcl10 in multiple cell types important for the generation of Ang II-induced cardiac damage and electric remodeling and may provide a new avenue for therapeutic intervention.

  2. Role of TGF-β on cardiac structural and electrical remodeling

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    Roberto Ramos-Mondragón

    2008-12-01

    Full Text Available Roberto Ramos-Mondragón, Carlos A Galindo, Guillermo AvilaDepartamento de Bioquímica, Cinvestav-IPN, MéxicoAbstract: The type β transforming growth factors (TGF-βs are involved in a number of human diseases, including heart failure and myocardial arrhythmias. In fact, during the last 20 years numerous studies have demonstrated that TGF-β affects the architecture of the heart under both normal and pathological conditions. Moreover, TGF-β signaling is currently under investigation, with the aim of discovering potential therapeutic roles in human disease. In contrast, only few studies have investigated whether TGF-β affects electrophysiological properties of the heart. This fact is surprising since electrical remodeling represents an important substrate for cardiac disease. This review discusses the potential role of TGF-β on cardiac excitation-contraction (EC coupling, action potentials, and ion channels. We also discuss the effects of TGF-β on cardiac development and disease from structural and electrophysiological points of view.Keywords: transforming growth factor, ion channel, cardiac electrophysiology

  3. Molecular Aspects of Exercise-induced Cardiac Remodeling.

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    Bernardo, Bianca C; McMullen, Julie R

    2016-11-01

    Exercise-induced cardiac remodeling is typically an adaptive response associated with cardiac myocyte hypertrophy and renewal, increased cardiac myocyte contractility, sarcomeric remodeling, cell survival, metabolic and mitochondrial adaptations, electrical remodeling, and angiogenesis. Initiating stimuli/triggers of cardiac remodeling include increased hemodynamic load, increased sympathetic activity, and the release of hormones and growth factors. Prolonged and strenuous exercise may lead to maladaptive exercise-induced cardiac remodeling including cardiac dysfunction and arrhythmia. In addition, this article describes novel therapeutic approaches for the treatment of heart failure that target mechanisms responsible for adaptive exercise-induced cardiac remodeling, which are being developed and tested in preclinical models.

  4. Angiotensin II Type 1 Receptor-Mediated Electrical Remodeling in Mouse Cardiac Myocytes.

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    Jeremy Kim

    Full Text Available We recently characterized an autocrine renin angiotensin system (RAS in canine heart. Activation of Angiotensin II Type 1 Receptors (AT1Rs induced electrical remodeling, including inhibition of the transient outward potassium current Ito, prolongation of the action potential (AP, increased calcium entry and increased contractility. Electrical properties of the mouse heart are very different from those of dog heart, but if a similar system existed in mouse, it could be uniquely studied through genetic manipulations. To investigate the presence of a RAS in mouse, we measured APs and Ito in isolated myocytes. Application of angiotensin II (A2 for 2 or more hours reduced Ito magnitude, without affecting voltage dependence, and prolonged APs in a dose-dependent manner. Based on dose-inhibition curves, the fast and slow components of Ito (Ito,fast and IK,slow appeared to be coherently regulated by [A2], with 50% inhibition at an A2 concentration of about 400 nM. This very high K0.5 is inconsistent with systemic A2 effects, but is consistent with an autocrine RAS in mouse heart. Pre-application of the microtubule destabilizing agent colchicine eliminated A2 effects on Ito and AP duration, suggesting these effects depend on intracellular trafficking. Application of the biased agonist SII ([Sar1-Ile4-Ile8]A2, which stimulates receptor internalization without G protein activation, caused Ito reduction and AP prolongation similar to A2-induced changes. These data demonstrate AT1R mediated regulation of Ito in mouse heart. Moreover, all measured properties parallel those measured in dog heart, suggesting an autocrine RAS may be a fundamental feedback system that is present across species.

  5. Exercise-induced cardiac remodeling.

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    Weiner, Rory B; Baggish, Aaron L

    2012-01-01

    Early investigations in the late 1890s and early 1900s documented cardiac enlargement in athletes with above-normal exercise capacity and no evidence of cardiovascular disease. Such findings have been reported for more than a century and continue to intrigue scientists and clinicians. It is well recognized that repetitive participation in vigorous physical exercise results in significant changes in myocardial structure and function. This process, termed exercise-induced cardiac remodeling (EICR), is characterized by structural cardiac changes including left ventricular hypertrophy with sport-specific geometry (eccentric vs concentric). Associated alterations in both systolic and diastolic functions are emerging as recognized components of EICR. The increasing popularity of recreational exercise and competitive athletics has led to a growing number of individuals exhibiting these findings in routine clinical practice. This review will provide an overview of EICR in athletes.

  6. Elevated sensitivity to cardiac ischemia in proteinuric rats is independent of adverse cardiac remodeling

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    Szymanski, Mariusz K.; Hillege, Hans L.; Danser, A. H. Jan; Garrelds, Ingrid M.; Schoemaker, Regien G.

    2013-01-01

    Objectives: Chronic renal dysfunction severely increases cardiovascular risk. Adverse cardiac remodeling is suggested to play a major role as predisposition for increased cardiac ischemic vulnerability. The aim of the present study was to examine the role of adverse cardiac remodeling in cardiac sen

  7. Effects of electrical and structural remodeling on atrial fibrillation maintenance: a simulation study.

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    Krogh-Madsen, Trine; Abbott, Geoffrey W; Christini, David J

    2012-01-01

    Atrial fibrillation, a common cardiac arrhythmia, often progresses unfavourably: in patients with long-term atrial fibrillation, fibrillatory episodes are typically of increased duration and frequency of occurrence relative to healthy controls. This is due to electrical, structural, and contractile remodeling processes. We investigated mechanisms of how electrical and structural remodeling contribute to perpetuation of simulated atrial fibrillation, using a mathematical model of the human atrial action potential incorporated into an anatomically realistic three-dimensional structural model of the human atria. Electrical and structural remodeling both shortened the atrial wavelength--electrical remodeling primarily through a decrease in action potential duration, while structural remodeling primarily slowed conduction. The decrease in wavelength correlates with an increase in the average duration of atrial fibrillation/flutter episodes. The dependence of reentry duration on wavelength was the same for electrical vs. structural remodeling. However, the dynamics during atrial reentry varied between electrical, structural, and combined electrical and structural remodeling in several ways, including: (i) with structural remodeling there were more occurrences of fragmented wavefronts and hence more filaments than during electrical remodeling; (ii) dominant waves anchored around different anatomical obstacles in electrical vs. structural remodeling; (iii) dominant waves were often not anchored in combined electrical and structural remodeling. We conclude that, in simulated atrial fibrillation, the wavelength dependence of reentry duration is similar for electrical and structural remodeling, despite major differences in overall dynamics, including maximal number of filaments, wave fragmentation, restitution properties, and whether dominant waves are anchored to anatomical obstacles or spiralling freely.

  8. Electrical and myocardial remodeling in primary aldosteronism

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    Mario eCurione

    2014-11-01

    Full Text Available Objective and design: primary aldosteronism (PA represents the most common cause of secondary hypertension. An higher risk of cardiovascular events has been reported in patients with PA than otherwise similar patients with essential hypertension (EH. At today few studies has been investigated the electrocardiographic changes in PA patients compared to EH patients.Methods: to investigate the electrocardiographic changes and heart remodeling in PA we enrolled 61 consecutive patients, 30 with PA (12 with aldosterone producing adenoma-APA and 18 with bilateral adrenal hyperplasia-IHA and 30 with EH. In all subjects electrelectrocardiographic parameters were evaluated from 12-lead electrocardiograms and heart remodeling with echocardiogram.Results: no significant differences in age, sex , body mass index (BMI and blood pressure were found in two groups. The P wave and PR interval duration were significantly prolonged in patientswith PA respect to EH (p< 0.003 and p< 0.002, respectively. First degree atrioventricular block was present in 16% patient with PA and only in 3.2% patients with EH. In PA patients the interventricular septum thickness (IVST correlated with left ventricular mass indecized (LVMi (r= 0.54; p< 0.04, and with PR duration (r= 0.51; p< 0.03. Left ventricular hypertrophy (LVH was present in 53% patients with PA and in 26% patients with EH (χ2 p<0.03.Conclusions: in this case-control study, patients with PA show more anatomic and electrical heart remodeling than those with EH. We hypothesize that in patients with PA these cardiac changes may play a role for the increased risk of future cardiovascular events.

  9. Galectin-3 and post-myocardial infarction cardiac remodeling

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    Meijers, Wouter C.; van der Velde, A. Rogier; Pascual-Figal, Domingo A.; de Boer, Rudolf A.

    2015-01-01

    This review summarizes the current literature regarding the involvement and the putative role(s) of galectin-3 in post-myocardial infarction cardiac remodeling. Post-myocardial infarction remodeling is characterized by acute loss of myocardium, which leads to structural and biomechanical changes in

  10. Ouabain induces cardiac remodeling in rats independent of blood pressure

    Institute of Scientific and Technical Information of China (English)

    Xing JIANG; Yan-ping REN; Zhuo-ren L(U)

    2007-01-01

    Aim: To investigate the ouabain's effects on cardiac remodeling in rats. Methods:Male Sprague-Dawley rats were treated with ouabain. Systolic blood pressure(SBP) was recorded weekly. After 4 and 6 weeks, echocardiography were performed,hemodynamic parameters were measured by invasive cardiac catheterization,changes in cardiac ultrastructure were analyzed using transmission electron microscopy, the collagen fraction of the left ventricle was assessed with Picrosirius red stain, and RT-PCR was applied to evaluate the mRNA level of myosin heavy chain-α and-β in the left ventricle. Results: Having been treated with ouabain for 4 weeks, there was no significant difference in the mean SBP of the two groups.However, left ventricular hypertrophy, myocardial ultrastructure deterioration,and extracellular matrix remodeling were induced by ouabain treatment; meanwhile,cardiac systolic and diastolic performance were both worsened. Moreover, the cardiac MHC-β mRNA was upregulated by ouabain treatment, whereas MHC-αmRNA was downregulated. After 4 weeks, the mean SBP in the ouabain group began to increase and was significantly higher than that in control group after 6 weeks (P<0.01); the rats' cardiac structure and function were worsened.Conclusion: These results suggested that ouabain induces alterations in cardiac structure and function, and the effects happened before the increase of blood pressure. The results indicated that ouabain induced cardiac remodeling in rats independent of blood pressure.

  11. Pentoxifylline Attenuates Cardiac Remodeling Induced by Tobacco Smoke Exposure

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    Minicucci, Marcos; Oliveira, Fernando; Santos, Priscila; Polegato, Bertha; Roscani, Meliza; Fernandes, Ana Angelica; Lustosa, Beatriz; Paiva, Sergio; Zornoff, Leonardo; Azevedo, Paula, E-mail: paulasa@fmb.unesp.br [Faculdade de Medicina de Botucatu, Universidade Estadual Paulista, São Paulo, SP (Brazil)

    2016-05-15

    Tobacco smoke exposure is an important risk factor for cardiac remodeling. Under this condition, inflammation, oxidative stress, energy metabolism abnormalities, apoptosis, and hypertrophy are present. Pentoxifylline has anti‑inflammatory, anti-apoptotic, anti-thrombotic and anti-proliferative properties. The present study tested the hypothesis that pentoxifylline would attenuate cardiac remodeling induced by smoking. Wistar rats were distributed in four groups: Control (C), Pentoxifylline (PX), Tobacco Smoke (TS), and PX-TS. After two months, echocardiography, invasive blood pressure measurement, biochemical, and histological studies were performed. The groups were compared by two-way ANOVA with a significance level of 5%. TS increased left atrium diameter and area, which was attenuated by PX. In the isolated heart study, TS lowered the positive derivate (+dp/dt), and this was attenuated by PX. The antioxidants enzyme superoxide dismutase and glutathione peroxidase were decreased in the TS group; PX recovered these activities. TS increased lactate dehydrogenase (LDH) and decreased 3-hydroxyacyl Coenzyme A dehydrogenases (OH-DHA) and citrate synthase (CS). PX attenuated LDH, 3-OH-DHA and CS alterations in TS-PX group. TS increased IL-10, ICAM-1, and caspase-3. PX did not influence these variables. TS induced cardiac remodeling, associated with increased inflammation, oxidative stress, apoptosis, and changed energy metabolism. PX attenuated cardiac remodeling by reducing oxidative stress and improving cardiac bioenergetics, but did not act upon cardiac cytokines and apoptosis.

  12. Hypothyroidism and its rapid correction alter cardiac remodeling.

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    Georges Hajje

    Full Text Available The cardiovascular effects of mild and overt thyroid disease include a vast array of pathological changes. As well, thyroid replacement therapy has been suggested for preserving cardiac function. However, the influence of thyroid hormones on cardiac remodeling has not been thoroughly investigated at the molecular and cellular levels. The purpose of this paper is to study the effect of hypothyroidism and thyroid replacement therapy on cardiac alterations. Thirty Wistar rats were divided into 2 groups: a control (n = 10 group and a group treated with 6-propyl-2-thiouracil (PTU (n = 20 to induce hypothyroidism. Ten of the 20 rats in the PTU group were then treated with L-thyroxine to quickly re-establish euthyroidism. The serum levels of inflammatory markers, such as C-reactive protein (CRP, tumor necrosis factor alpha (TNF-α, interleukin 6 (IL6 and pro-fibrotic transforming growth factor beta 1 (TGF-β1, were significantly increased in hypothyroid rats; elevations in cardiac stress markers, brain natriuretic peptide (BNP and cardiac troponin T (cTnT were also noted. The expressions of cardiac remodeling genes were induced in hypothyroid rats in parallel with the development of fibrosis, and a decline in cardiac function with chamber dilation was measured by echocardiography. Rapidly reversing the hypothyroidism and restoring the euthyroid state improved cardiac function with a decrease in the levels of cardiac remodeling markers. However, this change further increased the levels of inflammatory and fibrotic markers in the plasma and heart and led to myocardial cellular infiltration. In conclusion, we showed that hypothyroidism is related to cardiac function decline, fibrosis and inflammation; most importantly, the rapid correction of hypothyroidism led to cardiac injuries. Our results might offer new insights for the management of hypothyroidism-induced heart disease.

  13. RSK3 – A Regulator of Pathological Cardiac Remodeling

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    Martinez, Eliana C.; Passariello, Catherine L.; Li, Jinliang; Matheson, Christopher J.; Dodge-Kafka, Kimberly; Reigan, Philip; Kapiloff, Michael S.

    2015-01-01

    Summary The family of p90 ribosomal S6 kinases (RSK) are pleiotropic effectors for extracellular signal-regulated kinase (ERK) signaling pathways. Recently, RSK3 was shown to be important for pathological remodeling of the heart. While cardiac myocyte hypertrophy can be compensatory for increased wall stress, in chronic heart diseases this non-mitotic cell growth is usually associated with interstitial fibrosis, increased cell death, and decreased cardiac function. Although RSK3 is less abundant in the cardiac myocyte than other RSK family members, RSK3 appears to serve a unique role in cardiac myocyte stress responses. A potential mechanism conferring RSK3’s unique function in the heart is anchoring by the scaffold protein muscle A-kinase Anchoring Protein β (mAKAPβ). Recent findings suggest that RSK3 should be considered as a therapeutic target for the prevention of heart failure, a clinical syndrome of major public health significance. PMID:25988524

  14. Intradialytic Hypotension and Cardiac Remodeling: A Vicious Cycle

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    Chia-Ter Chao

    2015-01-01

    Full Text Available Hemodynamic instability during hemodialysis is a common but often underestimated issue in the nephrologist practice. Intradialytic hypotension, namely, a decrease of systolic or mean blood pressure to a certain level, prohibits the safe and smooth achievement of ultrafiltration and solute removal goal in chronic dialysis patients. Studies have elucidated the potential mechanisms involved in the development of Intradialytic hypotension, including excessive ultrafiltration and loss of compensatory mechanisms for blood pressure maintenance. Cardiac remodeling could also be one important piece of the puzzle. In this review, we intend to discuss the role of cardiac remodeling, including left ventricular hypertrophy, in the development of Intradialytic hypotension. In addition, we will also provide evidence that a bidirectional relationship might exist between Intradialytic hypotension and left ventricular hypertrophy in chronic dialysis patients. A more complete understanding of the complex interactions in between could assist the readers in formulating potential solutions for the reduction of both phenomena.

  15. ECG manifestations of left ventricular electrical remodeling.

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    Estes, E Harvey

    2012-01-01

    Research and thinking about the electrocardiographic manifestations of left ventricular hypertrophy has been constrained by a limited conceptual model of the process: heart disease produces chamber enlargement (increased mass), which in turn produces an altered electrocardiogram. The process is much more complex than can be represented in this simple model. A more robust and intricate model is proposed, in which heart (and vascular) disease causes structural changes, electrical changes, biochemical changes, and others, all of which interact to produce electrical remodeling of ventricular myocardium. This electrical remodeling results in a variety of ECG changes. All of these changes interact, leading to an altered clinical course, and to premature death. It is suggested that research, based on this model, can provide new clues to the processes involved, and improve the prediction of clinical outcomes. New directions in research, in recording equipment, and in organizational activities are suggested to test this new model, and to improve the usefulness of the electrocardiogram as a research and diagnostic tool.

  16. mAKAP – A Master Scaffold for Cardiac Remodeling

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    Passariello, Catherine L.; Li, Jinliang; Dodge-Kafka, Kimberly; Kapiloff, Michael S.

    2014-01-01

    Cardiac remodeling is regulated by an extensive intracellular signal transduction network. Each of the many signaling pathways in this network contributes uniquely to the control of cellular adaptation. In the last few years, it has become apparent that multimolecular signaling complexes or ‘signalosomes’ are important for fidelity in intracellular signaling and for mediating crosstalk between the different signaling pathways. These complexes integrate upstream signals and control downstream effectors. In the cardiac myocyte, the protein mAKAPβ serves as a scaffold for a large signalosome that is responsive to cAMP, calcium, hypoxia, and mitogen-activated protein kinase signaling. The main function of mAKAPβ signalosomes is to modulate stress-related gene expression regulated by the transcription factors NFATc, MEF2 and HIF-1α and type II histone deacetylases that control pathological cardiac hypertrophy. PMID:25551320

  17. Cardiac remodeling and physical training post myocardial infarction

    Institute of Scientific and Technical Information of China (English)

    Michael; A; Garza; Emily; A; Wason; John; Q; Zhang

    2015-01-01

    After myocardial infarction(MI), the heart undergoes extensive myocardial remodeling through the accumulation of fibrous tissue in both the infarcted and noninfarcted myocardium, which distorts tissue structure, increases tissue stiffness, and accounts for ventricular dysfunction. There is growing clinical consensus that exercise training may beneficially alter the course of post-MI myocardial remodeling and improve cardiac function. This review summarizes the present state of knowledge regarding the effect of post-MI exercise training on infarcted hearts. Due to the degree of difficulty to study a viable human heart at both protein and molecular levels, most of the detailed studies have been performed by using animal models. Although there are some negative reports indicating that post-MI exercise may further cause deterioration of the wounded hearts, a growing body of research from both human and animal experiments demonstrates that post-MI exercise may beneficially alter the course of wound healing and improve cardiac function. Furthermore, the improved function is likely due to exercise training-induced mitigation of reninangiotensin-aldosterone system, improved balance between matrix metalloproteinase-1 and tissue inhibitor of matrix metalloproteinase-1, favorable myosin heavy chain isoform switch, diminished oxidative stress, enhanced antioxidant capacity, improved mitochondrial calcium handling, and boosted myocardial angiogenesis. Additionally, meta-analyses revealed that exercise-based cardiac rehabilitation has proven to be effective, and remains one of the least expensive therapies for both the prevention and treatment of cardiovascular disease, and prevents re-infarction.

  18. The Cardiac TBX5 Interactome Reveals a Chromatin Remodeling Network Essential for Cardiac Septation.

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    Waldron, Lauren; Steimle, Jeffrey D; Greco, Todd M; Gomez, Nicholas C; Dorr, Kerry M; Kweon, Junghun; Temple, Brenda; Yang, Xinan Holly; Wilczewski, Caralynn M; Davis, Ian J; Cristea, Ileana M; Moskowitz, Ivan P; Conlon, Frank L

    2016-02-08

    Human mutations in the cardiac transcription factor gene TBX5 cause congenital heart disease (CHD), although the underlying mechanism is unknown. We report characterization of the endogenous TBX5 cardiac interactome and demonstrate that TBX5, long considered a transcriptional activator, interacts biochemically and genetically with the nucleosome remodeling and deacetylase (NuRD) repressor complex. Incompatible gene programs are repressed by TBX5 in the developing heart. CHD mis-sense mutations that disrupt the TBX5-NuRD interaction cause depression of a subset of repressed genes. Furthermore, the TBX5-NuRD interaction is required for heart development. Phylogenetic analysis showed that the TBX5-NuRD interaction domain evolved during early diversification of vertebrates, simultaneous with the evolution of cardiac septation. Collectively, this work defines a TBX5-NuRD interaction essential to cardiac development and the evolution of the mammalian heart, and when altered may contribute to human CHD.

  19. Aggravated Cardiac Remodeling post Aortocaval Fistula in Unilateral Nephrectomized Rats.

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    Jie Wu

    Full Text Available Aortocaval fistula (AV in rat is a unique model of volume-overload congestive heart failure and cardiac hypertrophy. Living donor kidney transplantation is regarded as beneficial to allograft recipients and not particularly detrimental to the donors. Impact of AV on animals with mild renal dysfunction is not fully understood. In this study, we explored the effects of AV in unilateral nephrectomized (UNX rats.Adult male Sprague-Dawley (SD rats were divided into Sham (n = 10, UNX (right kidney remove, n = 10, AV (AV established between the levels of renal arteries and iliac bifurcation, n = 18 and UNX+AV (AV at one week after UNX, n = 22, respectively. Renal outcome was measured by glomerular filtration rate, effective renal plasma flow, fractional excretion of sodium, albuminuria, plasma creatinine, and cystatin C. Focal glomerulosclerosis (FGS incidence was evaluated by renal histology. Cardiac function was measured by echocardiography and hemodynamic measurements.UNX alone induced compensatory left kidney enlargement, increased plasma creatinine and cystatin C levels, and slightly reduced glomerular filtration rate and increased FGS. AV induced significant cardiac enlargement and hypertrophy and reduced cardiac function and increased FGS, these changes were aggravated in UNX+AV rats.Although UNX only induces minor renal dysfunction, additional chronic volume overload placement during the adaptation phase of the remaining kidney is associated with aggravated cardiac dysfunction and remodeling in UNX rats, suggesting special medical care is required for UNX or congenital monokidney subjects in case of chronic volume overload as in the case of pregnancy and hyperthyroidism to prevent further adverse cardiorenal events in these individuals.

  20. Lasting alterations of the sodium current by short-term hyperlipidemia as a mechanism for initiation of cardiac remodeling.

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    Biet, M; Morin, N; Benrezzak, O; Naimi, F; Bellanger, S; Baillargeon, J P; Chouinard, L; Gallo-Payet, N; Carpentier, A C; Dumaine, R

    2014-01-15

    Clinical and animal studies indicate that increased fatty acid delivery to lean tissues induces cardiac electrical remodeling and alterations of cellular calcium homeostasis. Since this may represent a mechanism initiating cardiac dysfunction during establishment of insulin resistance and diabetes or anaerobic cardiac metabolism (ischemia), we sought to determine if short-term exposure to high plasma concentration of fatty acid in vivo was sufficient to alter the cardiac sodium current (INa) in dog ventricular myocytes. Our results show that delivery of triglycerides and nonesterified fatty acids by infusion of Intralipid + heparin (IH) for 8 h increased the amplitude of INa by 43% and shifted its activation threshold by -5 mV, closer to the resting membrane potential. Steady-state inactivation (availability) of the channels was reduced by IH with no changes in recovery from inactivation. As a consequence, INa "window" current, a strong determinant of intracellular Na+ and Ca2+ concentrations, was significantly increased. The results indicate that increased circulating fatty acids alter INa gating in manners consistent with an increased cardiac excitability and augmentation of intracellular calcium. Moreover, these changes could still be measured after the dogs were left to recover for 12 h after IH perfusion, suggesting lasting changes in INa. Our results indicate that fatty acids rapidly induce cardiac remodeling and suggest that this process may be involved in the development of cardiac dysfunctions associated to insulin resistance and diabetes.

  1. Gender-related differences in β-adrenergic receptor-mediated cardiac remodeling.

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    Zhu, Baoling; Liu, Kai; Yang, Chengzhi; Qiao, Yuhui; Li, Zijian

    2016-12-01

    Cardiac remodeling is the pathological basis of various cardiovascular diseases. In this study, we found gender-related differences in β-adrenergic receptor (AR)-mediated pathological cardiac remodeling. Cardiac remodeling model was established by subcutaneous injection of isoprenaline (ISO) for 14 days. Heart rate (HR), mean arterial pressure (MAP), and echocardiography were obtained on 7th and 14th days during ISO administration. Myocardial cross-sectional area and the ratio of heart mass to tibia length (HM/TL) were detected to assess cardiac hypertrophy. Picro-Sirius red staining (picric acid + Sirius red F3B) was used to evaluate cardiac fibrosis. Myocardial capillary density was assessed by immunohistochemistry for von Willebrand factor. Further, real-time PCR was used to measure the expression of β1-AR and β2-AR. Results showed that ISO induced cardiac remodeling, the extent of which was different between female and male mice. The extent of increase in cardiac wall thickness, myocardial cross-sectional area, and collagen deposition in females was less than that in males. However, no gender-related difference was observed in HR, MAP, cardiac function, and myocardial capillary density. The distinctive decrease of β2-AR expression, rather than a decrease of β1-AR expression, seemed to result in gender-related differences in cardiac remodeling.

  2. Childhood obesity and cardiac remodeling: from cardiac structure to myocardial mechanics.

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    Tadic, Marijana; Cuspidi, Cesare

    2015-08-01

    Epidemic of obesity, especially morbid obesity, among children and adolescents, is a key factor associated with the dramatic increase in prevalence of type 2 diabetes mellitus, arterial hypertension, and metabolic syndrome in this population. Furthermore, childhood obesity represents a very important predictor of obesity in adulthood that is related to cardiovascular and cerebrovascular diseases. Overweight and obesity in children and adolescents are associated with impairment of cardiac structure and function. The majority of studies investigated the influence of obesity on left ventricular remodeling. However, the impact of obesity on the right ventricle, both the atria, and myocardial mechanics has been insufficiently studied. The aim of this review article is to summarize all data about heart remodeling in childhood, from cardiac size, throughout systolic and diastolic function, to myocardial mechanics, using a wide range of mainly echocardiographic techniques and parameters. Additionally, we sought to present current knowledge about the influence of weight loss, achieved by various therapeutic approaches, on the improvement of cardiac geometry, structure, and function in obese children and adolescents.

  3. Signs of cardiac autonomic imbalance and proarrhythmic remodeling in FTO deficient mice.

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    Luca Carnevali

    Full Text Available In humans, variants of the fat mass and obesity associated (FTO gene have recently been associated with obesity. However, the physiological function of FTO is not well defined. Previous investigations in mice have linked FTO deficiency to growth retardation, loss of white adipose tissue, increased energy metabolism and enhanced systemic sympathetic activation. In this study we investigated for the first time the effects of global knockout of the mouse FTO gene on cardiac function and its autonomic neural regulation. ECG recordings were acquired via radiotelemetry in homozygous knockout (n = 12 and wild-type (n = 8 mice during resting and stress conditions, and analyzed by means of time- and frequency-domain indexes of heart rate variability. In the same animals, cardiac electrophysiological properties (assessed by epicardial mapping and structural characteristics were investigated. Our data indicate that FTO knockout mice were characterized by (i higher heart rate values during resting and stress conditions, (ii heart rate variability changes (increased LF to HF ratio, (iii larger vulnerability to stress-induced tachyarrhythmias, (iv altered ventricular repolarization, and (v cardiac hypertrophy compared to wild-type counterparts. We conclude that FTO deficiency in mice leads to an imbalance of the autonomic neural modulation of cardiac function in the sympathetic direction and to a potentially proarrhythmic remodeling of electrical and structural properties of the heart.

  4. Downregulation of β-Adrenoceptors in Isoproterenol-Induced Cardiac Remodeling through HuR.

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    Qian Yin

    Full Text Available β-adrenergic receptors (β-ARs play an important role in cardiac remodeling, which is the key pathological process in various heart diseases and leads to heart failure. However, the regulation of β-AR expression in remodeling hearts is still unclear. This study aims to clarify the possible mechanisms underlying the regulation of β1- and β2-AR expression in cardiac remodeling. The rat model of cardiac remodeling was established by subcutaneous injection of isoproterenol(ISO at the dose of 0.25 mg·kg(-1·d(-1 for 7 days. We found that the expression of β1- and β2-ARs decreased in the remodeling heart. The mechanisms may include the inhibition of DNA transcription and the increase of mRNA degradation. cAMP-response element binding protein(CREB is a well-known transcription factor of β-AR. However, the expression and activation of CREB was not changed in the remodeling heart. Further, human Antigen-R (HuR, a RNA binding protein, which binds to the 3'-untranslated region of the β-AR mRNA and promotes RNA degradation, was increased in the remodeling model. And in vitro, HuR deficiency reversed the reduction of β-AR mRNA induced by ISO. Therefore, the present findings indicate that HuR, but not CREB, is responsible for the reduction of β-AR expression in ISO induced cardiac remodeling.

  5. Stress-dependent cardiac remodeling occurs in the absence of microRNA-21 in mice

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    Patrick, David M; Montgomery, Rusty L; Qi, Xiaoxia

    2010-01-01

    contractility comparable to wild. type littermates. Similarly, inhibition of miR-21 through intravenous delivery of a locked nucleic acid-modified (LNA-modified) antimiR oligonucleotide also failed to block the remodeling response of the heart to stress. We therefore conclude that miR-21 is not essential...... for pathological cardiac remodeling....

  6. Cardiac remodeling and myocardial dysfunction in obese spontaneously hypertensive rats

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    Linz Dominik

    2012-09-01

    Full Text Available Abstract Background The additive effects of obesity and metabolic syndrome on left ventricular (LV maladaptive remodeling and function in hypertension are not characterized. Methods We compared an obese spontaneously hypertensive rat model (SHR-ob with lean spontaneously hypertensive rats (SHR-lean and normotensive controls (Ctr. LV-function was investigated by cardiac magnetic resonance imaging and invasive LV-pressure measurements. LV-interstitial fibrosis was quantified and protein levels of phospholamban (PLB, Serca2a and glucose transporters (GLUT1 and GLUT4 were determined by immunohistochemistry. Results Systolic blood pressure was similar in SHR-lean and SHR-ob (252 ± 7 vs. 242 ± 7 mmHg, p = 0.398 but was higher when compared to Ctr (155 ± 2 mmHg, p  Conclusion In addition to hypertension alone, metabolic syndrome and obesity adds to the myocardial phenotype by aggravating diastolic dysfunction and a progression towards systolic dysfunction. SHR-ob may be a useful model to develop new interventional and pharmacological treatment strategies for hypertensive heart disease and metabolic disorders.

  7. Exercise-Induced Cardiac Remodeling: Lessons from Humans, Horses, and Dogs

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    Rob Shave

    2017-02-01

    Full Text Available Physical activity is dependent upon the cardiovascular system adequately delivering blood to meet the metabolic and thermoregulatory demands of exercise. Animals who regularly exercise therefore require a well-adapted heart to support this delivery. The purpose of this review is to examine cardiac structure, and the potential for exercise-induced cardiac remodeling, in animals that regularly engage in strenuous activity. Specifically, we draw upon the literature that has studied the “athlete’s heart” in humans, horses, and dogs, to enable the reader to compare and contrast cardiac remodeling in these three athletic species. The available literature provides compelling evidence for exercise-induced cardiac remodeling in all three species. However, more work is required to understand the influence of species/breed specific genetics and exercise-related hemodynamics, in order to fully understand the impact of exercise on cardiac structure.

  8. Defective branched chain amino acid catabolism contributes to cardiac dysfunction and remodeling following myocardial infarction.

    Science.gov (United States)

    Wang, Wei; Zhang, Fuyang; Xia, Yunlong; Zhao, Shihao; Yan, Wenjun; Wang, Helin; Lee, Yan; Li, Congye; Zhang, Ling; Lian, Kun; Gao, Erhe; Cheng, Hexiang; Tao, Ling

    2016-11-01

    Cardiac metabolic remodeling is a central event during heart failure (HF) development following myocardial infarction (MI). It is well known that myocardial glucose and fatty acid dysmetabolism contribute to post-MI cardiac dysfunction and remodeling. However, the role of amino acid metabolism in post-MI HF remains elusive. Branched chain amino acids (BCAAs) are an important group of essential amino acids and function as crucial nutrient signaling in mammalian animals. The present study aimed to determine the role of cardiac BCAA metabolism in post-MI HF progression. Utilizing coronary artery ligation-induced murine MI models, we found that myocardial BCAA catabolism was significantly impaired in response to permanent MI, therefore leading to an obvious elevation of myocardial BCAA abundance. In MI-operated mice, oral BCAA administration further increased cardiac BCAA levels, activated the mammalian target of rapamycin (mTOR) signaling, and exacerbated cardiac dysfunction and remodeling. These data demonstrate that BCAAs act as a direct contributor to post-MI cardiac pathologies. Furthermore, these BCAA-mediated deleterious effects were improved by rapamycin cotreatment, revealing an indispensable role of mTOR in BCAA-mediated adverse effects on cardiac function/structure post-MI. Of note, pharmacological inhibition of branched chain ketoacid dehydrogenase kinase (BDK), a negative regulator of myocardial BCAA catabolism, significantly improved cardiac BCAA catabolic disorders, reduced myocardial BCAA levels, and ameliorated post-MI cardiac dysfunction and remodeling. In conclusion, our data provide the evidence that impaired cardiac BCAA catabolism directly contributes to post-MI cardiac dysfunction and remodeling. Moreover, improving cardiac BCAA catabolic defects may be a promising therapeutic strategy against post-MI HF.

  9. Angiotensin II dependent cardiac remodeling in the eel Anguilla anguilla involves the NOS/NO system

    DEFF Research Database (Denmark)

    Filice, Mariacristina; Amelio, Daniela; Garofalo, Filippo

    2017-01-01

    Angiotensin II (AngII), the principal effector of the Renin-Angiotensin System (RAS), plays an important role in controlling mammalian cardiac morpho-functional remodelling. In the eel Anguilla anguilla, one month administration of AngII improves cardiac performance and influences the expression...

  10. Enhancing cardiac repair : targeting I/R injury and adverse remodeling

    NARCIS (Netherlands)

    Arslan, F.

    2011-01-01

    In this thesis, we have investigated novel therapeutic targets to enhance cardiac repair and improve cardiac function after myocardial infarction. We have tried to approach this objective by targeting 3 major determinants of post-infarct adverse remodeling and subsequent heart function deterioration

  11. Air pollution and adverse cardiac remodeling: clinical effects and basic mechanisms

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    Yonggang eLiu

    2015-05-01

    Full Text Available EExposure to air pollution has long been known to trigger cardiovascular events, primarily through activation of local and systemic inflammatory pathways that affect the vasculature. Detrimental effects of air pollution exposure on heart failure and cardiac remodeling have also been described in human populations. Recent studies in both human subjects and animal models have provided insights into the basic physiological, cellular and molecular mechanisms that play a role in adverse cardiac remodeling. This review will give a brief overview of the relationship between air pollution and cardiovascular disease, describe the clinical effects of air pollution exposure on cardiac remodeling, describe the basic mechanisms that affect remodeling as described in human and animal systems and will discuss future areas of investigation.

  12. Air pollution and adverse cardiac remodeling: clinical effects and basic mechanisms.

    Science.gov (United States)

    Liu, Yonggang; Goodson, Jamie M; Zhang, Bo; Chin, Michael T

    2015-01-01

    Exposure to air pollution has long been known to trigger cardiovascular events, primarily through activation of local and systemic inflammatory pathways that affect the vasculature. Detrimental effects of air pollution exposure on heart failure and cardiac remodeling have also been described in human populations. Recent studies in both human subjects and animal models have provided insights into the basic physiological, cellular and molecular mechanisms that play a role in adverse cardiac remodeling. This review will give a brief overview of the relationship between air pollution and cardiovascular disease, describe the clinical effects of air pollution exposure on cardiac remodeling, describe the basic mechanisms that affect remodeling as described in human and animal systems and will discuss future areas of investigation.

  13. Calcitriol attenuates cardiac remodeling and dysfunction in a murine model of polycystic ovary syndrome.

    Science.gov (United States)

    Gao, Ling; Cao, Jia-Tian; Liang, Yan; Zhao, Yi-Chao; Lin, Xian-Hua; Li, Xiao-Cui; Tan, Ya-Jing; Li, Jing-Yi; Zhou, Cheng-Liang; Xu, Hai-Yan; Sheng, Jian-Zhong; Huang, He-Feng

    2016-05-01

    Polycystic ovary syndrome (PCOS) is a complex reproductive and metabolic disorder affecting 10 % of reproductive-aged women, and is well associated with an increased prevalence of cardiovascular risk factors. However, there are few data concerning the direct association of PCOS with cardiac pathologies. The present study aims to investigate the changes in cardiac structure, function, and cardiomyocyte survival in a PCOS model, and explore the possible effect of calcitriol administration on these changes. PCOS was induced in C57BL/6J female mice by chronic dihydrotestosterone administration, as evidenced by irregular estrous cycles, obesity and dyslipidemia. PCOS mice progressively developed cardiac abnormalities including cardiac hypertrophy, interstitial fibrosis, myocardial apoptosis, and cardiac dysfunction. Conversely, concomitant administration of calcitriol significantly attenuated cardiac remodeling and cardiomyocyte apoptosis, and improved cardiac function. Molecular analysis revealed that the beneficial effect of calcitriol was associated with normalized autophagy function by increasing phosphorylation levels of AMP-activated protein kinase and inhibiting phosphorylation levels of mammalian target of rapamycin complex. Our findings provide the first evidence for the presence of cardiac remodeling in a PCOS model, and vitamin D supplementation may be a potential therapeutic strategy for the prevention and treatment of PCOS-related cardiac remodeling.

  14. Role of matricellular proteins in cardiac tissue remodeling after myocardial infarction

    Institute of Scientific and Technical Information of China (English)

    Yutaka; Matsui; Junko; Morimoto; Toshimitsu; Uede

    2010-01-01

    After onset of myocardial infarction(MI),the left ventricle(LV) undergoes a continuum of molecular,cellular,and extracellular responses that result in LV wall thinning,dilatation,and dysfunction.These dynamic changes in LV shape,size,and function are termed cardiac remodeling.If the cardiac healing after MI does not proceed properly,it could lead to cardiac rupture or maladaptive cardiac remodeling,such as further LV dilatation and dysfunction,and ultimately death.Although the precise molecular mechanisms in this cardiac healing process have not been fully elucidated,this process is strictly coordinated by the interaction of cells with their surrounding extracellular matrix(ECM) proteins.The components of ECM include basic structural proteins such as collagen,elastin and specialized proteins such as fibronectin,proteoglycans and matricellular proteins.Matricellular proteins are a class of non-structural and secreted proteins that probably exert regulatory functions through direct binding to cell surface receptors,other matrix proteins,and soluble extracellular factors such as growth factors and cytokines.This small group of proteins,which includesosteopontin,thrombospondin-1/2,tenascin,periostin,and secreted protein,acidic and rich in cysteine,shows a low level of expression in normal adult tissue,but is markedly upregulated during wound healing and tissue remodeling,including MI.In this review,we focus on the regulatory functions of matricellular proteins during cardiac tissue healing and remodeling after MI.

  15. Effects of candesartan on electrical remodeling in the hearts of inherited dilated cardiomyopathy model mice.

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    Fuminori Odagiri

    Full Text Available Inherited dilated cardiomyopathy (DCM is characterized by dilatation and dysfunction of the ventricles, and often results in sudden death or heart failure (HF. Although angiotensin receptor blockers (ARBs have been used for the treatment of HF, little is known about the effects on postulated electrical remodeling that occurs in inherited DCM. The aim of this study was to examine the effects of candesartan, one of the ARBs, on cardiac function and electrical remodeling in the hearts of inherited DCM model mice (TNNT2 ΔK210. DCM mice were treated with candesartan in drinking water for 2 months from 1 month of age. Control, non-treated DCM mice showed an enlargement of the heart with prolongation of QRS and QT intervals, and died at t1/2 of 70 days. Candesartan dramatically extended the lifespan of DCM mice, suppressed cardiac dilatation, and improved the functional parameters of the myocardium. It also greatly suppressed prolongation of QRS and QT intervals and action potential duration (APD in the left ventricular myocardium and occurrence of ventricular arrhythmia. Expression analysis revealed that down-regulation of Kv4.2 (Ito channel protein, KChIP2 (auxiliary subunit of Kv4.2, and Kv1.5 (IKur channel protein in DCM was partially reversed by candesartan administration. Interestingly, non-treated DCM heart had both normal-sized myocytes with moderately decreased Ito and IKur and enlarged cells with greatly reduced K+ currents (Ito, IKur IK1 and Iss. Treatment with candesartan completely abrogated the emergence of the enlarged cells but did not reverse the Ito, and IKur in normal-sized cells in DCM hearts. Our results indicate that candesartan treatment suppresses structural remodeling to prevent severe electrical remodeling in inherited DCM.

  16. Cardiac remodeling in the mouse model of Marfan syndrome develops into two distinctive phenotypes.

    Science.gov (United States)

    Tae, Hyun-Jin; Petrashevskaya, Natalia; Marshall, Shannon; Krawczyk, Melissa; Talan, Mark

    2016-01-15

    Marfan syndrome (MFS) is a systemic disorder of connective tissue caused by mutations in fibrillin-1. Cardiac dysfunction in MFS has not been characterized halting the development of therapies of cardiac complication in MFS. We aimed to study the age-dependent cardiac remodeling in the mouse model of MFS FbnC1039G+/- mouse [Marfan heterozygous (HT) mouse] and its association with valvular regurgitation. Marfan HT mice of 2-4 mo demonstrated a mild hypertrophic cardiac remodeling with predominant decline of diastolic function and increased transforming growth factor-β canonical (p-SMAD2/3) and noncanonical (p-ERK1/2 and p-p38 MAPK) signaling and upregulation of hypertrophic markers natriuretic peptides atrium natriuretic peptide and brain natriuretic peptide. Among older HT mice (6-14 mo), cardiac remodeling was associated with two distinct phenotypes, manifesting either dilated or constricted left ventricular chamber. Dilatation of left ventricular chamber was accompanied by biochemical evidence of greater mechanical stress, including elevated ERK1/2 and p38 MAPK phosphorylation and higher brain natriuretic peptide expression. The aortic valve regurgitation was registered in 20% of the constricted group and 60% of the dilated group, whereas mitral insufficiency was observed in 40% of the constricted group and 100% of the dilated group. Cardiac dysfunction was not associated with the increase of interstitial fibrosis and nonmyocyte proliferation. In the mouse model fibrillin-1, haploinsufficiency results in the early onset of nonfibrotic hypertrophic cardiac remodeling and dysfunction, independently from valvular abnormalities. MFS heart is vulnerable to stress-induced cardiac dilatation in the face of valvular regurgitation, and stress-activated MAPK signals represent a potential target for cardiac management in MFS.

  17. Effects of Long-term Right Ventricular Apical Pacing on Left Ventricular Remodeling and Cardiac Function

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Objective: To investigate the impacts of long-term right ventricular apical pacing on the ventricular remodeling and cardiac functions of patients with high-grade and third-degree atrioventricular blockage with normal heart structures and cardiac functions. In addition, we provide many evidences for choosing an optimal electrode implantation site.Methods: Study participants included patients who were admitted for pacemaker replacements and revisited for examinations of implanted pacemakers at outpatient. Pa...

  18. Relationship Between Reverse Remodeling and Cardiopulmonary Exercise Capacity in Heart Failure Patients Undergoing Cardiac Resynchronization Therapy

    NARCIS (Netherlands)

    Mastenbroek, Mirjam H; van t Sant, Jetske; Versteeg, Henneke; Cramer, MJ; Doevendans, Pieter A; Pedersen, Susanne S; Meine, Mathias

    2016-01-01

    BACKGROUND: Studies on the relationship between left ventricular reverse remodeling and cardiopulmonary exercise capacity in heart failure patients undergoing cardiac resynchronization therapy (CRT) are scarce and inconclusive. METHODS AND RESULTS: Eighty-four patients with a 1st-time CRT-defibrilla

  19. Autoantibodies against α1 adrenergic receptor related with cardiac remodeling in hypertensive patients by clinical observation

    Institute of Scientific and Technical Information of China (English)

    李正在

    2006-01-01

    Objective To investigate the effects of autoantibodies against a adrenergic receptor on cardiac remodeling in patients with hypertension. Methods Five hundred and fifty three patients with hypertension in our hospital were selected. The autoantibodies againstα1 adrenergic receptor in sera of donor were detected by ELISA, and the Results of echocardiography were recorded. By

  20. Effect of phentolamine on myocardial extracellular matrix of cardiac remodeling in rats

    Institute of Scientific and Technical Information of China (English)

    Yi-Gang Yin; Ru-Zhu Wang; Zhong-Bao Ruan; Li Zhu

    2014-01-01

    Objective:To study the effects of phentolamine on myocardial extracellular matrix of cardiac remodeling induced by norepinephrine in rats.Methods:24SD rats were divided into3 groups randomly: control groups, norepinephrine groups(model groups), norepinephrine+phentolamine groups(treatment groups).Echocardiography was used to detect changes in cardiac structure and function, the level of collagen volume fraction(CVF) and hydroxyproline as well as collagen content were determined in myocardial tissue, matrix metalloproteinases-2 and collagen Ⅰ in myocardial tissue were localized by immunohistochemitry.Results:Compared with control groups, left ventricular hypertrophy in the model group rats, the hydroxyproline content and CVF was significantly higher(P<0.01), and matrix metalloproteinase-2 and collagen Ⅰ protein expression was significantly increased(P<0.01).Phentolamine significantly improved cardiac hypertrophy in treatment group rats, reduced hydroxyproline,CVF, matrix metalloproteinase2 and collagen Ⅰprotein expression(P<0.05).Conclusions:Phentolamine can effectively reduce the incidence of myocardial hypertrophy and myocardial extracellular matrix remodeling inSD rats, and it can ease myocardial extracellular matrix of cardiac remodeling.It may be associated with reduced expression of matrix metalloproteinase2 and collagen Ⅰ in myocardial tissue remodeling.

  1. ECG marker of adverse electrical remodeling post-myocardial infarction predicts outcomes in MADIT II study.

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    Larisa G Tereshchenko

    Full Text Available BACKGROUND: Post-myocardial infarction (MI structural remodeling is characterized by left ventricular dilatation, fibrosis, and hypertrophy of the non-infarcted myocardium. OBJECTIVE: The goal of our study was to quantify post-MI electrical remodeling by measuring the sum absolute QRST integral (SAI QRST. We hypothesized that adverse electrical remodeling predicts outcomes in MADIT II study participants. METHODS: Baseline orthogonal ECGs of 750 MADIT II study participants (448 [59.7%] ICD arm were analyzed. SAI QRST was measured as the arithmetic sum of absolute QRST integrals over all three orthogonal ECG leads. The primary endpoint was defined as sudden cardiac death (SCD or sustained ventricular tachycardia (VT/ventricular fibrillation (VF with appropriate ICD therapies. All-cause mortality served as a secondary endpoint. RESULTS: Adverse electrical remodeling in post-MI patients was characterized by wide QRS, increased magnitudes of spatial QRS and T vectors, J-point deviation, and QTc prolongation. In multivariable Cox regression analysis after adjustment for age, QRS duration, atrial fibrillation, New York Heart Association heart failure class and blood urea nitrogen, SAI QRST predicted SCD/VT/VF (HR 1.33 per 100 mV*ms (95%CI 1.11-1.59; P = 0.002, and all-cause death (HR 1.27 per 100 mV*ms (95%CI 1.03-1.55, P = 0.022 in both arms. No interaction with therapy arm and bundle branch block (BBB status was found. CONCLUSIONS: In MADIT II patients, increased SAI QRST is associated with increased risk of sustained VT/VF with appropriate ICD therapies and all-cause death in both ICD and in conventional medical therapy arms, and in patients with and without BBB. Further studies of SAI QRST are warranted.

  2. Electrical stimulation systems for cardiac tissue engineering.

    Science.gov (United States)

    Tandon, Nina; Cannizzaro, Christopher; Chao, Pen-Hsiu Grace; Maidhof, Robert; Marsano, Anna; Au, Hoi Ting Heidi; Radisic, Milica; Vunjak-Novakovic, Gordana

    2009-01-01

    We describe a protocol for tissue engineering of synchronously contractile cardiac constructs by culturing cardiac cells with the application of pulsatile electrical fields designed to mimic those present in the native heart. Tissue culture is conducted in a customized chamber built to allow for cultivation of (i) engineered three-dimensional (3D) cardiac tissue constructs, (ii) cell monolayers on flat substrates or (iii) cells on patterned substrates. This also allows for analysis of the individual and interactive effects of pulsatile electrical field stimulation and substrate topography on cell differentiation and assembly. The protocol is designed to allow for delivery of predictable electrical field stimuli to cells, monitoring environmental parameters, and assessment of cell and tissue responses. The duration of the protocol is 5 d for two-dimensional cultures and 10 d for 3D cultures.

  3. Quantitative proteomic changes during post myocardial infarction remodeling reveals altered cardiac metabolism and Desmin aggregation in the infarct region.

    Science.gov (United States)

    Datta, Kaberi; Basak, Trayambak; Varshney, Swati; Sengupta, Shantanu; Sarkar, Sagartirtha

    2017-01-30

    Myocardial infarction is one of the leading causes of cardiac dysfunction, failure and sudden death. Post infarction cardiac remodeling presents a poor prognosis, with 30%-45% of patients developing heart failure, in a period of 5-25years. Oxidative stress has been labelled as the primary causative factor for cardiac damage during infarction, however, the impact it may have during the process of post infarction remodeling has not been well probed. In this study, we have implemented iTRAQ proteomics to catalogue proteins and functional processes, participating both temporally (early and late phases) and spatially (infarct and remote zones), during post myocardial infarction remodeling of the heart as functions of the differential oxidative stress manifest during the remodeling process. Cardiac metabolism was the dominant network to be affected during infarction and the remodeling time points considered in this study. A distinctive expression pattern of cytoskeletal proteins was also observed with increased remodeling time points. Further, it was found that the cytoskeletal protein Desmin, aggregated in the infarct zone during the remodeling process, mediated by the protease Calpain1. Taken together, all of these data in conjunction may lay the foundation to understand the effects of oxidative stress on the remodeling process and elaborate the mechanism behind the compromised cardiac function observed during post myocardial infarction remodeling.

  4. Adenoviral short hairpin RNA targeting phosphodiesterase 5 attenuates cardiac remodeling and cardiac dysfunction following myocardial infarction in mice

    Institute of Scientific and Technical Information of China (English)

    张健

    2014-01-01

    Objective To observe the impact of PDE5shRNA on cardiac remodeling and heart function following myocardial infarction in mice.Methods Myocardial infarction(MI)was induced in mice by left coronary artery ligation.Mice were randomly assigned to sham operation group(n=6),PDE5shRNA group(n=12),common adenovirus group(n=15)and DMEM group(n=8).Four weeks post-MI,the survival rate was evaluated.

  5. Contrary microRNA Expression Pattern Between Fetal and Adult Cardiac Remodeling: Therapeutic Value for Heart Failure.

    Science.gov (United States)

    Yan, Hualin; Li, Yifei; Wang, Chuan; Zhang, Yi; Liu, Cong; Zhou, Kaiyu; Hua, Yimin

    2016-08-10

    microRNAs (miRNAs) belong to a class of non-coding RNAs that regulate post-transcriptional gene expression during development and disease. Growing evidence indicates abundant miRNA expression changes and their important role in cardiac hypertrophy and failure. However, the role of miRNAs in fetal cardiac remodeling is little known. Here, we investigated the altered expression of fifteen miRNAs in rat fetal cardiac remodeling compared with adult cardiac remodeling. Among fifteen tested miRNAs, eleven and five miRNAs (miR-199a-5p, miR-214-3p, miR-155-3p, miR-155-5p and miR-499-5p) are significantly differentially expressed in fetal and adult cardiac remodeling, respectively. After comparison of miRNA expression in fetal and adult cardiac remodeling, we find that miRNA expression returns to the fetal level in adult cardiac failure and is activated in advance of the adult level in fetal failure. The current study highlights the contrary expression pattern between fetal and adult cardiac remodeling and that supports a novel potential therapeutic approach to treating heart failure.

  6. Aggravated myocardial infarction-induced cardiac remodeling and heart failure in histamine-deficient mice

    Science.gov (United States)

    Chen, Jinmiao; Hong, Tao; Ding, Suling; Deng, Long; Abudupataer, Mieradilijiang; Zhang, Weiwei; Tong, Minghong; Jia, Jianguo; Gong, Hui; Zou, Yunzeng; Wang, Timothy C.; Ge, Junbo; Yang, Xiangdong

    2017-01-01

    Histamine has pleiotropic pathophysiological effects, but its role in myocardial infarction (MI)-induced cardiac remodeling remains unclear. Histidine decarboxylase (HDC) is the main enzyme involved in histamine production. Here, we clarified the roles of HDC-expressing cells and histamine in heart failure post-MI using HDC-EGFP transgenic mice and HDC-knockout (HDC−/−) mice. HDC+CD11b+ myeloid cell numbers markedly increased in the injured hearts, and histamine levels were up-regulated in the circulation post-MI. HDC−/− mice exhibited more adverse cardiac remodeling, poorer left ventricular function and higher mortality by increasing cardiac fibrogenesis post-MI. In vitro assays further confirmed that histamine inhibited heart fibroblast proliferation. Furthermore, histamine enhanced the signal transducer and activator of transcription (STAT)-6 phosphorylation level in murine heart fibroblasts, and the inhibitive effects of histamine on fibroblast proliferation could be blocked by JAK3/STAT6 signaling selective antagonist. STAT6-knockout (STAT6−/−) mice had a phenotype similar to that of HDC−/− mice post-MI; however, in contrast to HDC−/− mice, the beneficial effects of exogenous histamine injections were abrogated in STAT6−/− mice. These data suggest that histamine exerts protective effects by modulating cardiac fibrosis and remodeling post-MI, in part through the STAT6-dependent signaling pathway. PMID:28272448

  7. Alteration of RhoA Prenylation Ameliorates Cardiac and Vascular Remodeling in Spontaneously Hypertensive Rats

    Directory of Open Access Journals (Sweden)

    Jian Yang

    2016-06-01

    Full Text Available Background: In our previous study, farnesyl pyrophosphate synthase (FPPS was shown to be increased in spontaneously hypertensive rats (SHR and in mice with angiotensin-II induced cardiac hypertrophy. Overexpression of FPPS induced cardiac hypertrophy and fibrosis in mice, accompanied by an increase in the synthesis of farnesyl pyrophosphate (FPP and geranylgeranyl pyrophosphate (GGPP. In the present study, we investigated the mechanisms of reversing cardiovascular remodeling in SHR by inhibiting FPPS. Methods and Results: Six-week-old rats were given vehicle or an FPPS inhibitor (alendronate, 100 ug/kg/d daily for twelve weeks by osmotic mini-pump. The results demonstrated that FPPS inhibition attenuated cardiac hypertrophy and fibrosis in SHR as shown by the heart weight to body weight ratio, echocardiographic parameters, and histological examination. In addition, FPPS inhibition attenuated aortic remodeling as shown by reduced media thickness, media cross-sectional area and collagen of the aorta as well as SBP, DBP, MBP. Furthermore, 12 weeks of alendronate treatment significantly decreased FPP and GGPP levels, RhoA activation and geranylgeranylation in the heart and aorta, all of which were significantly upregulated in SHR compared with normotensive Wistar-Kyoto rats. Conclusion: Taken together, these results indicate that chronic treatment with alendronate decreases the development of cardiac and aortic remodeling, by a pathway which involves inhibition of the geranylgeranylation and activation of RhoA.

  8. The Role of Nrf2-Mediated Pathway in Cardiac Remodeling and Heart Failure

    Directory of Open Access Journals (Sweden)

    Shanshan Zhou

    2014-01-01

    Full Text Available Heart failure (HF is frequently the consequence of sustained, abnormal neurohormonal, and mechanical stress and remains a leading cause of death worldwide. The key pathophysiological process leading to HF is cardiac remodeling, a term referring to maladaptation to cardiac stress at the molecular, cellular, tissue, and organ levels. HF and many of the conditions that predispose one to HF are associated with oxidative stress. Increased generation of reactive oxygen species (ROS in the heart can directly lead to increased necrosis and apoptosis of cardiomyocytes which subsequently induce cardiac remodeling and dysfunction. Nuclear factor-erythroid-2- (NF-E2- related factor 2 (Nrf2 is a transcription factor that controls the basal and inducible expression of a battery of antioxidant genes and other cytoprotective phase II detoxifying enzymes that are ubiquitously expressed in the cardiovascular system. Emerging evidence has revealed that Nrf2 and its target genes are critical regulators of cardiovascular homeostasis via the suppression of oxidative stress, which is the key player in the development and progression of HF. The purpose of this review is to summarize evidence that activation of Nrf2 enhances endogenous antioxidant defenses and counteracts oxidative stress-associated cardiac remodeling and HF.

  9. Early remodeling of rat cardiac muscle induced by swimming training

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    Verzola R.M.M.

    2006-01-01

    Full Text Available The aim of the present investigation was to study the effect of acute swimming training with an anaerobic component on matrix metallopeptidase (MMP activity and myosin heavy chain gene expression in the rat myocardium. Animals (male Wistar rats, weighing approximately 180 g were trained for 6 h/day in 3 sessions of 2 h each for 1 to 5 consecutive days (N = 5 rats per group. Rats swam in basins 47 cm in diameter and 60 cm deep filled with water at 33 to 35ºC. After the training period a significant increase (P < 0.05 was observed in the heart weight normalized to body weight by about 22 and 35% in the groups that trained for 96 and 120 h, respectively. Blood lactate levels were significantly increased (P < 0.05 in all groups after all training sessions, confirming an anaerobic component. However, lactate levels decreased (P < 0.05 with days of training, suggesting that the animals became adapted to this protocol. Myosin heavy chain-ß gene expression, analyzed by real time PCR and normalized with GAPDH gene expression, showed a significant two-fold increase (P < 0.01 after 5 days of training. Zymography analysis of myocardium extracts indicated a single ~60-kDa activity band that was significantly increased (P < 0.05 after 72, 96, and 120 h, indicating an increased expression of MMP-2 and suggesting precocious remodeling. Furthermore, the presence of MMP-2 was confirmed by Western blot analysis, but not the presence of MMP-1 and MMP-3. Taken together, our results indicate that in these training conditions, the rat heart undergoes early biochemical and functional changes required for the adaptation to the new physiological condition by tissue remodeling.

  10. Small interfering RNA therapy against carbohydrate sulfotransferase 15 inhibits cardiac remodeling in rats with dilated cardiomyopathy.

    Science.gov (United States)

    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.

  11. Periostin as a modulator of chronic cardiac remodeling after myocardial infarction

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    Marcos F. Minicucci

    2013-10-01

    Full Text Available OBJECTIVE: After acute myocardial infarction, during the cardiac repair phase, periostin is released into the infarct and activates signaling pathways that are essential for the reparative process. However, the role of periostin in chronic cardiac remodeling after myocardial infarction remains to be elucidated. Therefore, the objective of this study was to investigate the relationship between tissue periostin and cardiac variables in the chronic cardiac remodeling induced by myocardial infarction. METHODS: Male Wistar rats were assigned to 2 groups: a simulated surgery group (SHAM; n = 8 and a myocardial infarction group (myocardial infarction; n = 13. After 3 months, morphological, functional and biochemical analyses were performed. The data are expressed as means±SD or medians (including the lower and upper quartiles. RESULTS: Myocardial infarctions induced increased left ventricular diastolic and systolic areas associated with a decreased fractional area change and a posterior wall shortening velocity. With regard to the extracellular matrix variables, the myocardial infarction group presented with higher values of periostin and types I and III collagen and higher interstitial collagen volume fractions and myocardial hydroxyproline concentrations. In addition, periostin was positively correlated with type III collagen levels (r = 0.673, p = 0.029 and diastolic (r = 0.678, p = 0.036 and systolic (r = 0.795, p = 0.006 left ventricular areas. Considering the relationship between periostin and the cardiac function variables, periostin was inversely correlated with both the fractional area change (r = -0.783, p = 0.008 and the posterior wall shortening velocity (r = -0.767, p = 0.012. CONCLUSIONS: Periostin might be a modulator of deleterious cardiac remodeling in the chronic phase after myocardial infarction in rats.

  12. Genetic Dissection of Cardiac Remodeling in an Isoproterenol-Induced Heart Failure Mouse Model.

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    Jessica Jen-Chu Wang

    2016-07-01

    Full Text Available We aimed to understand the genetic control of cardiac remodeling using an isoproterenol-induced heart failure model in mice, which allowed control of confounding factors in an experimental setting. We characterized the changes in cardiac structure and function in response to chronic isoproterenol infusion using echocardiography in a panel of 104 inbred mouse strains. We showed that cardiac structure and function, whether under normal or stress conditions, has a strong genetic component, with heritability estimates of left ventricular mass between 61% and 81%. Association analyses of cardiac remodeling traits, corrected for population structure, body size and heart rate, revealed 17 genome-wide significant loci, including several loci containing previously implicated genes. Cardiac tissue gene expression profiling, expression quantitative trait loci, expression-phenotype correlation, and coding sequence variation analyses were performed to prioritize candidate genes and to generate hypotheses for downstream mechanistic studies. Using this approach, we have validated a novel gene, Myh14, as a negative regulator of ISO-induced left ventricular mass hypertrophy in an in vivo mouse model and demonstrated the up-regulation of immediate early gene Myc, fetal gene Nppb, and fibrosis gene Lgals3 in ISO-treated Myh14 deficient hearts compared to controls.

  13. MT1-MMP-dependent remodeling of cardiac extracellular matrix structure and function following myocardial infarction.

    Science.gov (United States)

    Koenig, Gerald C; Rowe, R Grant; Day, Sharlene M; Sabeh, Farideh; Atkinson, Jeffrey J; Cooke, Kenneth R; Weiss, Stephen J

    2012-05-01

    The myocardial extracellular matrix (ECM), an interwoven meshwork of proteins, glycoproteins, proteoglycans, and glycosaminoglycans that is dominated by polymeric fibrils of type I collagen, serves as the mechanical scaffold on which myocytes are arrayed for coordinated and synergistic force transduction. Following ischemic injury, cardiac ECM remodeling is initiated via localized proteolysis, the bulk of which has been assigned to matrix metalloproteinase (MMP) family members. Nevertheless, the key effector(s) of myocardial type I collagenolysis both in vitro and in vivo have remained unidentified. In this study, using cardiac explants from mice deficient in each of the major type I collagenolytic MMPs, including MMP-13, MMP-8, MMP-2, MMP-9, or MT1-MMP, we identify the membrane-anchored MMP, MT1-MMP, as the dominant collagenase that is operative within myocardial tissues in vitro. Extending these observations to an in vivo setting, mice heterozygous for an MT1-MMP-null allele display a distinct survival advantage and retain myocardial function relative to wild-type littermates in an experimental model of myocardial infarction, effects associated with preservation of the myocardial type I collagen network as a consequence of the decreased collagenolytic potential of cardiac fibroblasts. This study identifies MT1-MMP as a key MMP responsible for effecting postinfarction cardiac ECM remodeling and cardiac dysfunction.

  14. Monocytes increase human cardiac myofibroblast-mediated extracellular matrix remodeling through TGF-β1.

    Science.gov (United States)

    Mewhort, Holly E M; Lipon, Brodie D; Svystonyuk, Daniyil A; Teng, Guoqi; Guzzardi, David G; Silva, Claudia; Yong, V Wee; Fedak, Paul W M

    2016-03-15

    Following myocardial infarction (MI), cardiac myofibroblasts remodel the extracellular matrix (ECM), preventing mechanical complications. However, prolonged myofibroblast activity leads to dysregulation of the ECM, maladaptive remodeling, fibrosis, and heart failure (HF). Chronic inflammation is believed to drive persistent myofibroblast activity; however, the mechanisms are unclear. We assessed the influence of peripheral blood monocytes on human cardiac myofibroblast activity in a three-dimensional (3D) ECM microenvironment. Human cardiac myofibroblasts isolated from surgical biopsies of the right atrium and left ventricle were seeded into 3D collagen matrices. Peripheral blood monocytes were isolated from healthy human donors and cocultured with myofibroblasts. Monocytes increased myofibroblast activity measured by collagen gel contraction (baseline: 57.6 ± 5.9% vs. coculture: 65.2 ± 7.1% contraction; P matrix metalloproteinase 9 compared with baseline (122.9 ± 10.1 pg/ml and 3,496.0 ± 190.4 pg/ml, respectively, vs. 21.5 ± 16.3 pg/ml and 183.3 ± 43.9 pg/ml; P matrix. Peripheral blood monocyte interaction with human cardiac myofibroblasts stimulates myofibroblast activity through release of TGF-β1. These data implicate inflammation as a potential driver of cardiac fibrosis.

  15. Atrophic cardiac remodeling induced by taurine deficiency in Wistar rats.

    Directory of Open Access Journals (Sweden)

    Mariele Castilho Pansani

    Full Text Available INTRODUCTION: Micronutrient deficiency is observed in heart failure patients. Taurine, for example, represents 50% of total free amino acids in the heart, and in vivo studies have linked taurine deficiency with cardiomyopathy. METHODS: Thirty-four male Wistar rats (body weight = 100 g were weighed and randomly assigned to one of two groups: Control (C or taurine-deficient (T (-. Beta-alanine at a concentration of 3% was added to the animals' water to induce taurine deficiency in the T (- group. On day 30, the rats were individually submitted to echocardiography; morphometrical and histopathological evaluation and metalloproteinase activity, oxidative stress and inflammation evaluation were performed. Tissue samples were collected to determine the taurine concentration in the heart. RESULTS: Taurine deficiency led to decreases in: ventricular wall thickness, left ventricle dry weight, myocyte sectional area, left ventricle posterior wall thickness and ventricular geometry. With regard to heart function, the velocity of the A wave, the ratio between the E and A wave, the ejection fraction, fractional shortening and cardiac output values were decreased in T (- rats, suggesting abnormal diastolic and systolic function. Increased fibrosis, inflammation and increased activation of metalloproteinases were not observed. Oxidative stress was increased in deficient animals. CONCLUSIONS: These data suggest that taurine deficiency promotes structural and functional cardiac alterations with unique characteristics.

  16. Impact of family hypertension history on exercise-induced cardiac remodeling.

    Science.gov (United States)

    Baggish, Aaron L; Weiner, Rory B; Yared, Kibar; Wang, Francis; Kupperman, Eli; Hutter, Adolph M; Picard, Michael H; Wood, Malissa J

    2009-07-01

    Left ventricular (LV) hypertrophy is a well-established, but highly variable, finding among exercise-trained persons. The causes for the variability in LV remodeling in response to exercise training remain incompletely understood. The present study sought to determine whether a family history of hypertension is a determinant of the cardiac response to exercise training. The cardiac parameters in 60 collegiate rowers (30 men/30 women; age 19.8 +/- 1.1 years) with (family history positive [FH+], n = 22) and without (family history negative [FH-], n = 38) a FH of hypertension were studied with echocardiography before and after 90 days of rowing training. The LV mass increased significantly in both groups. However, the LV mass increased significantly more in FH- persons (Delta 17 +/- 5 g/m(2)) than in FH+ persons (Delta 9 +/- 6 g/m(2), p hypertrophy between the 2 groups. FH- athletes experienced eccentric LV hypertrophy (relative wall thickness index 0.39 +/- 0.4) characterized by LV dilation. In contrast, FH+ athletes developed concentric LV hypertrophy (relative wall thickness index 0.44 +/- 0.3; p eccentric LV remodeling in FH- athletes was associated with a more robust enhancement of LV diastolic function than the concentric LV remodeling that occurred in FH+ athletes. In conclusion, these findings suggest that patterns of exercise-induced LV remodeling are strongly associated with FH history status.

  17. Exogenous midkine administration prevents cardiac remodeling in pacing-induced congestive heart failure of rabbits.

    Science.gov (United States)

    Harada, Masahide; Hojo, Mayumi; Kamiya, Kaichiro; Kadomatsu, Kenji; Murohara, Toyoaki; Kodama, Itsuo; Horiba, Mitsuru

    2016-01-01

    Midkine (MK), a heparin-binding growth factor, has been shown to prevent cardiac remodeling after ischemic injury through its anti-apoptotic effect. Cell apoptosis is central to the pathophysiology of cardiac remodeling in congestive heart failure (CHF) of ischemic as well as non-ischemic origin. We hypothesized that MK exerts the anti-apoptotic cardioprotective effect in CHF of non-ischemic etiology. MK protein or vehicle (normal saline) was subcutaneously administered in tachycardia-induced CHF rabbits (right ventricular pacing, 350 beats/min, 4 weeks). The vehicle-treated rabbits (n = 19, control) demonstrated severe CHF and high mortality rate, whereas MK (n = 16) demonstrated a well-compensated state and a lower mortality rate. In echocardiography, left ventricular (LV) end-diastolic dimension decreased in MK versus control, whereas LV systolic function increased. In histological analysis (picrosirius red staining), MK decreased collagen deposition area compared with control. TUNEL staining showed that MK prevented cell apoptosis and minimized myocyte loss in the CHF rabbit ventricle, associated with activation of PI3-K/Akt signaling, producing a parallel decrease of Bax/Bcl-2 ratio. MK prevented progression of cardiac remodeling in the CHF rabbit, likely by activation of anti-apoptotic signaling. Exogenous MK application might be a novel therapeutic strategy for CHF due to non-ischemic origin.

  18. Role of mitogen-activated protein kinase pathways in multifactorial adverse cardiac remodeling associated with metabolic syndrome.

    Science.gov (United States)

    Asrih, Mohamed; Mach, François; Nencioni, Alessio; Dallegri, Franco; Quercioli, Alessandra; Montecucco, Fabrizio

    2013-01-01

    Metabolic syndrome has been widely associated with an increased risk for acute cardiovascular events. Emerging evidence supports metabolic syndrome as a condition favoring an adverse cardiac remodeling, which might evolve towards heart dysfunction and failure. This pathological remodeling has been described to result from the cardiac adaptive response to clinical mechanical conditions (such as hypertension, dyslipidemia, and hyperglycemia), soluble inflammatory molecules (such as cytokines and chemokines), as well as hormones (such as insulin), characterizing the pathophysiology of metabolic syndrome. Moreover, these cardiac processes (resulting in cardiac hypertrophy and fibrosis) are also associated with the modulation of intracellular signalling pathways within cardiomyocytes. Amongst the different intracellular kinases, mitogen-activated protein kinases (MAPKs) were shown to be involved in heart damage in metabolic syndrome. However, their role remains controversial. In this paper, we will discuss and update evidence on MAPK-mediated mechanisms underlying cardiac adverse remodeling associated with metabolic syndrome.

  19. Role of Mitogen-Activated Protein Kinase Pathways in Multifactorial Adverse Cardiac Remodeling Associated with Metabolic Syndrome

    Directory of Open Access Journals (Sweden)

    Mohamed Asrih

    2013-01-01

    Full Text Available Metabolic syndrome has been widely associated with an increased risk for acute cardiovascular events. Emerging evidence supports metabolic syndrome as a condition favoring an adverse cardiac remodeling, which might evolve towards heart dysfunction and failure. This pathological remodeling has been described to result from the cardiac adaptive response to clinical mechanical conditions (such as hypertension, dyslipidemia, and hyperglycemia, soluble inflammatory molecules (such as cytokines and chemokines, as well as hormones (such as insulin, characterizing the pathophysiology of metabolic syndrome. Moreover, these cardiac processes (resulting in cardiac hypertrophy and fibrosis are also associated with the modulation of intracellular signalling pathways within cardiomyocytes. Amongst the different intracellular kinases, mitogen-activated protein kinases (MAPKs were shown to be involved in heart damage in metabolic syndrome. However, their role remains controversial. In this paper, we will discuss and update evidence on MAPK-mediated mechanisms underlying cardiac adverse remodeling associated with metabolic syndrome.

  20. Targeted inhibition of Focal Adhesion Kinase Attenuates Cardiac Fibrosis and Preserves Heart Function in Adverse Cardiac Remodeling

    Science.gov (United States)

    Zhang, Jie; Fan, Guangpu; Zhao, Hui; Wang, Zhiwei; Li, Fei; Zhang, Peide; Zhang, Jing; Wang, Xu; Wang, Wei

    2017-01-01

    Cardiac fibrosis in post-myocardial infarction (MI), seen in both infarcted and non-infarcted myocardium, is beneficial to the recovery of heart function. But progressively pathological fibrosis impairs ventricular function and leads to poor prognosis. FAK has recently received attention as a potential mediator of fibrosis, our previous study reported that pharmacological inhibition of FAK can attenuate cardiac fibrosis in post MI models. However, the long-term effects on cardiac function and adverse cardiac remodelling were not clearly investigated. In this study, we tried to determine the preliminary mechanisms in regulating CF transformation to myofibroblasts and ECM synthesis relevant to the development of adverse cardiac remolding in vivo and in vitro. Our study provides even more evidence that FAK is directly related to the activation of CF in hypoxia condition in a dose-dependent and time-dependent manner. Pharmacological inhibition of FAK significantly reduces myofibroblast differentiation; our in vivo data demonstrated that a FAK inhibitor significantly decreases fibrotic score, and preserves partial left ventricular function. Both PI3K/AKT signalling and ERK1/2 are necessary for hypoxia-induced CF differentiation and ECM synthesis; this process also involves lysyl oxidase (LOX). These findings suggest that pharmacological inhibition of FAK may become an effective therapeutic strategy against adverse fibrosis. PMID:28225063

  1. Cardiac Function Remains Impaired Despite Reversible Cardiac Remodeling after Acute Experimental Viral Myocarditis

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    Peter Moritz Becher

    2017-01-01

    Full Text Available Background. Infection with Coxsackievirus B3 induces myocarditis. We aimed to compare the acute and chronic phases of viral myocarditis to identify the immediate effects of cardiac inflammation as well as the long-term effects after resolved inflammation on cardiac fibrosis and consequently on cardiac function. Material and Methods. We infected C57BL/6J mice with Coxsackievirus B3 and determined the hemodynamic function 7 as well as 28 days after infection. Subsequently, we analyzed viral burden and viral replication in the cardiac tissue as well as the expression of cytokines and matrix proteins. Furthermore, cardiac fibroblasts were infected with virus to investigate if viral infection alone induces profibrotic signaling. Results. Severe cardiac inflammation was determined and cardiac fibrosis was consistently colocalized with inflammation during the acute phase of myocarditis. Declined cardiac inflammation but no significantly improved hemodynamic function was observed 28 days after infection. Interestingly, cardiac fibrosis declined to basal levels as well. Both cardiac inflammation and fibrosis were reversible, whereas the hemodynamic function remains impaired after healed viral myocarditis in C57BL/6J mice.

  2. Apocynin improving cardiac remodeling in chronic renal failure disease is associated with up-regulation of epoxyeicosatrienoic acids.

    Science.gov (United States)

    Zhang, Kun; Liu, Yu; Liu, Xiaoqiang; Chen, Jie; Cai, Qingqing; Wang, Jingfeng; Huang, Hui

    2015-09-22

    Cardiac remodeling is one of the most common cardiac abnormalities and associated with a high mortality in chronic renal failure (CRF) patients. Apocynin, a nicotinamide-adenine dinucleotide phosphate (NADPH) oxidase inhibitor, has been showed cardio-protective effects. However, whether apocynin can improve cardiac remodeling in CRF and what is the underlying mechanism are unclear. In the present study, we enrolled 94 participants. In addition, we used 5/6 nephrectomized rats to mimic cardiac remodeling in CRF. Serum levels of epoxyeicosatrienoic acids (EETs) and its mainly metabolic enzyme-soluble epoxide hydrolase (sEH) were measured. The results showed that the serum levels of EETs were significantly decreased in renocardiac syndrome participants (P < 0.05). In 5/6 nephrectomized CRF model, the ratio of left ventricular weight / body weight, left ventricular posterior wall thickness, and cardiac interstitial fibrosis were significantly increased while ejection fraction significantly decreased (P < 0.05). All these effects could partly be reversed by apocynin. Meanwhile, we found during the process of cardiac remodeling in CRF, apocynin significantly increased the reduced serum levels of EETs and decreased the mRNA and protein expressions of sEH in the heart (P < 0.05). Our findings indicated that the protective effect of apocynin on cardiac remodeling in CRF was associated with the up-regulation of EETs. EETs may be a new mediator for the injury of kidney-heart interactions.

  3. Remodeling of the sarcomeric cytoskeleton in cardiac ventricular myocytes during heart failure and after cardiac resynchronization therapy.

    Science.gov (United States)

    Lichter, Justin G; Carruth, Eric; Mitchell, Chelsea; Barth, Andreas S; Aiba, Takeshi; Kass, David A; Tomaselli, Gordon F; Bridge, John H; Sachse, Frank B

    2014-07-01

    Sarcomeres are the basic contractile units of cardiac myocytes. Recent studies demonstrated remodeling of sarcomeric proteins in several diseases, including genetic defects and heart failure. Here we investigated remodeling of sarcomeric α-actinin in two models of heart failure, synchronous (SHF) and dyssynchronous heart failure (DHF), as well as a model of cardiac resynchronization therapy (CRT). We applied three-dimensional confocal microscopy and quantitative methods of image analysis to study isolated cells from our animal models. 3D Fourier analysis revealed a decrease of the spatial regularity of the α-actinin distribution in both SHF and DHF versus control cells. The spatial regularity of α-actinin in DHF cells was reduced when compared with SHF cells. The spatial regularity of α-actinin was partially restored after CRT. We found longitudinal depositions of α-actinin in SHF, DHF and CRT cells. These depositions spanned adjacent Z-disks and exhibited a lower density of α-actinin than in the Z-disk. Differences in the occurrence of depositions between the SHF, CRT and DHF models versus control were significant. Also, CRT cells exhibited a higher occurrence of depositions versus SHF, but not DHF cells. Other sarcomeric proteins did not accumulate in the depositions to the same extent as α-actinin. We did not find differences in the expression of α-actinin protein and its encoding gene in our animal models. In summary, our studies indicate that HF is associated with two different types of remodeling of α-actinin and only one of those was reversed after CRT. We suggest that these results can guide us to an understanding of remodeling of structures and function associated with sarcomeres.

  4. Anti-CCL21 Antibody Attenuates Infarct Size and Improves Cardiac Remodeling After Myocardial Infarction

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    Yi Jiang

    2015-09-01

    Full Text Available Background/Aims: Over-activation of cellular inflammatory effectors adversely affects myocardial function after acute myocardial infarction (AMI. The CC-chemokine CCL21 is, via its receptor CCR7, one of the key regulators of inflammation and immune cell recruitment, participates in various inflammatory disorders, including cardiovascular ones. This study explored the therapeutic effect of an anti-CCL21 antibody in cardiac remodeling after myocardial infarction. Methods and Results: An animal model of AMI generated by left anterior descending coronary artery ligation in C57BL/6 mice resulted in higher levels of circulating CCL21 and cardiac CCR7. Neutralization of CCL21 by intravenous injection of anti-CCL21 monoclonal antibody reduced infarct size after AMI, decreased serum levels of neutrophil and monocyte chemo attractants post AMI, diminished neutrophil and macrophage recruitment in infarcted myocardium, and suppressed MMP-9 and total collagen content in myocardium. Anti-CCL21 treatment also limited cardiac enlargement and improved left ventricular function. Conclusions: Our study indicated that CCL21 was involved in cardiac remodeling post infarction and anti-CCL21 strategies might be useful in the treatment of AMI.

  5. High-septal pacing reduces ventricular electrical remodeling and proarrhythmia in chronic atrioventricular block dogs

    DEFF Research Database (Denmark)

    Winckels, Stephan K G; Thomsen, Morten Bækgaard; Oosterhoff, Peter

    2007-01-01

    This study was designed to analyze the relevance of ventricular activation patterns for ventricular electrical remodeling after atrioventricular (AV) block in dogs.......This study was designed to analyze the relevance of ventricular activation patterns for ventricular electrical remodeling after atrioventricular (AV) block in dogs....

  6. Temporal and Molecular Analyses of Cardiac Extracellular Matrix Remodeling following Pressure Overload in Adiponectin Deficient Mice.

    Directory of Open Access Journals (Sweden)

    Keith Dadson

    Full Text Available Adiponectin, circulating levels of which are reduced in obesity and diabetes, mediates cardiac extracellular matrix (ECM remodeling in response to pressure overload (PO. Here, we performed a detailed temporal analysis of progressive cardiac ECM remodelling in adiponectin knockout (AdKO and wild-type (WT mice at 3 days and 1, 2, 3 and 4 weeks following the induction of mild PO via minimally invasive transverse aortic banding. We first observed that myocardial adiponectin gene expression was reduced after 4 weeks of PO, whereas increased adiponectin levels were detected in cardiac homogenates at this time despite decreased circulating levels of adiponectin. Scanning electron microscopy and Masson's trichrome staining showed collagen accumulation increased in response to 2 and 4 weeks of PO in WT mice, while fibrosis in AdKO mice was notably absent after 2 weeks but highly apparent after 4 weeks of PO. Time and intensity of fibroblast appearance after PO was not significantly different between AdKO and WT animals. Gene array analysis indicated that MMP2, TIMP2, collagen 1α1 and collagen 1α3 were induced after 2 weeks of PO in WT but not AdKO mice. After 4 weeks MMP8 was induced in both genotypes, MMP9 only in WT mice and MMP1α only in AdKO mice. Direct stimulation of primary cardiac fibroblasts with adiponectin induced a transient increase in total collagen detected by picrosirius red staining and collagen III levels synthesis, as well as enhanced MMP2 activity detected via gelatin zymography. Adiponectin also enhanced fibroblast migration and attenuated angiotensin-II induced differentiation to a myofibroblast phenotype. In conclusion, these data indicate that increased myocardial bioavailability of adiponectin mediates ECM remodeling following PO and that adiponectin deficiency delays these effects.

  7. Effects of Growth Hormone on Cardiac Remodeling During Resistance Training in Rats

    Energy Technology Data Exchange (ETDEWEB)

    Junqueira, Adriana, E-mail: francispacagnelli@unoeste.br [Universidade do Oeste Paulista (UNOESTE), Presidente Prudente, SP (Brazil); Cicogna, Antônio Carlos [Universidade Estadual Paulista (UNESP), Campus Botucatu, SP (Brazil); Engel, Letícia Estevam; Aldá, Maiara Almeida [Universidade do Oeste Paulista (UNOESTE), Presidente Prudente, SP (Brazil); Tomasi, Loreta Casquel de [Universidade Estadual Paulista (UNESP), Campus Botucatu, SP (Brazil); Giuffrida, Rogério; Giometti, Inês Cristina [Universidade do Oeste Paulista (UNOESTE), Presidente Prudente, SP (Brazil); Freire, Ana Paula Coelho Figueira [Universidade do Oeste Paulista (UNOESTE), Presidente Prudente, SP (Brazil); Universidade Estadual Paulista (UNESP), Campus Presidente Prudente, SP (Brazil); Aguiar, Andreo Fernando [Universidade do Norte do Paraná, UNOPAR, Londrina, PR (Brazil); Pacagnelli, Francis Lopes [Universidade do Oeste Paulista (UNOESTE), Presidente Prudente, SP (Brazil)

    2016-01-15

    Although the beneficial effects of resistance training (RT) on the cardiovascular system are well established, few studies have investigated the effects of the chronic growth hormone (GH) administration on cardiac remodeling during an RT program. To evaluate the effects of GH on the morphological features of cardiac remodeling and Ca2+ transport gene expression in rats submitted to RT. Male Wistar rats were divided into 4 groups (n = 7 per group): control (CT), GH, RT and RT with GH (RTGH). The dose of GH was 0.2 IU/kg every other day for 30 days. The RT model used was the vertical jump in water (4 sets of 10 jumps, 3 bouts/wk) for 30 consecutive days. After the experimental period, the following variables were analyzed: final body weight (FBW), left ventricular weight (LVW), LVW/FBW ratio, cardiomyocyte cross-sectional area (CSA), collagen fraction, creatine kinase muscle-brain fraction (CK-MB) and gene expressions of SERCA2a, phospholamban (PLB) and ryanodine (RyR). There was no significant (p > 0.05) difference among groups for FBW, LVW, LVW/FBW ratio, cardiomyocyte CSA, and SERCA2a, PLB and RyR gene expressions. The RT group showed a significant (p < 0.05) increase in collagen fraction compared to the other groups. Additionally, the trained groups (RT and RTGH) had greater CK-MB levels compared to the untrained groups (CT and GH). GH may attenuate the negative effects of RT on cardiac remodeling by counteracting the increased collagen synthesis, without affecting the gene expression that regulates cardiac Ca{sup 2+} transport.

  8. Post-mortem cardiac diffusion tensor imaging: detection of myocardial infarction and remodeling of myofiber architecture

    Energy Technology Data Exchange (ETDEWEB)

    Winklhofer, Sebastian; Berger, Nicole; Stolzmann, Paul [University Hospital Zurich, Institute of Diagnostic and Interventional Radiology, Zurich (Switzerland); University of Zurich, Department of Forensic Medicine and Radiology, Institute of Forensic Medicine, Zurich (Switzerland); Stoeck, Christian T.; Kozerke, Sebastian [Institute for Biomedical Engineering University and ETH Zurich, Zurich (Switzerland); Thali, Michael [University of Zurich, Department of Forensic Medicine and Radiology, Institute of Forensic Medicine, Zurich (Switzerland); Manka, Robert [University Hospital Zurich, Institute of Diagnostic and Interventional Radiology, Zurich (Switzerland); Institute for Biomedical Engineering University and ETH Zurich, Zurich (Switzerland); University Hospital Zurich, Clinic for Cardiology, Zurich (Switzerland); Alkadhi, Hatem [University Hospital Zurich, Institute of Diagnostic and Interventional Radiology, Zurich (Switzerland)

    2014-11-15

    To investigate the accuracy of post-mortem diffusion tensor imaging (DTI) for the detection of myocardial infarction (MI) and to demonstrate the feasibility of helix angle (HA) calculation to study remodelling of myofibre architecture. Cardiac DTI was performed in 26 deceased subjects prior to autopsy for medicolegal reasons. Fractional anisotropy (FA) and mean diffusivity (MD) were determined. Accuracy was calculated on per-segment (AHA classification), per-territory, and per-patient basis, with pathology as reference standard. HAs were calculated and compared between healthy segments and those with MI. Autopsy demonstrated MI in 61/440 segments (13.9 %) in 12/26 deceased subjects. Healthy myocardial segments had significantly higher FA (p < 0.01) and lower MD (p < 0.001) compared to segments with MI. Multivariate logistic regression demonstrated that FA (p < 0.10) and MD (p = 0.01) with the covariate post-mortem time (p < 0.01) predicted MI with an accuracy of 0.73. Analysis of HA distribution demonstrated remodelling of myofibre architecture, with significant differences between healthy segments and segments with chronic (p < 0.001) but not with acute MI (p > 0.05). Post-mortem cardiac DTI enablesdifferentiation between healthy and infarcted myocardial segments by means of FA and MD. HA assessment allows for the demonstration of remodelling of myofibre architecture following chronic MI. (orig.)

  9. Finite Element Model of Cardiac Electrical Conduction.

    Science.gov (United States)

    Yin, John Zhihao

    1994-01-01

    In this thesis, we develop mathematical models to study electrical conduction of the heart. One important pattern of wave propagation of electrical excitation in the heart is reentry which is believed to be the underlying mechanism of some dangerous cardiac arhythmias such as ventricular tachycardia and ventricular fibrillation. We present in this thesis a new ionic channel model of the ventricular cardiac cell membrane to study the microscopic electrical properties of myocardium. We base our model on recent single channel experiment data and a simple physical diffusion model of the calcium channel. Our ionic channel model of myocardium has simpler differential equations and fewer parameters than previous models. Further more, our ionic channel model achieves better results in simulating the strength-interval curve when we connect the membrane patch model to form a one dimensional cardiac muscle strand. We go on to study a finite element model which uses multiple states and non-nearest neighbor interactions to include curvature and dispersion effects. We create a generalized lattice randomization to overcome the artifacts generated by the interaction between the local dynamics and the regularities of the square lattice. We show that the homogeneous model does not display spontaneous wavefront breakup in a reentrant wave propagation once the lattice artifacts have been smoothed out by lattice randomization with a randomization scale larger than the characteristic length of the interaction. We further develop a finite 3-D 3-state heart model which employs a probability interaction rule. This model is applied to the simulation of Body Surface Laplacian Mapping (BSLM) using a cylindrical volume conductor as the torso model. We show that BSLM has a higher spatial resolution than conventional mapping methods in revealing the underlying electrical activities of the heart. The results of these studies demonstrate that mathematical modeling and computer simulation are very

  10. Novel Protective Role of Myeloid Differentiation 1 in Pathological Cardiac Remodelling

    Science.gov (United States)

    Xiong, Xiaojv; Liu, Yu; Mei, Yang; Peng, Jianye; Wang, Zhiqiang; Kong, Bin; Zhong, Peng; Xiong, Liang; Quan, Dajun; Li, Qi; Wang, Guangji; Huang, He

    2017-01-01

    Myeloid differentiation 1 (MD-1), a secreted protein interacting with radioprotective 105 (RP105), plays an important role in Toll-like receptor 4 (TLR4) signalling pathway. Previous studies showed that MD-1 may be restricted in the immune system. In this study, we demonstrated for the first time that MD-1 was highly expressed in both human and animal hearts. We also discovered that cardiac-specific overexpression of MD-1 significantly attenuated pressure overload-induced cardiac hypertrophy, fibrosis, and dysfunction, whereas loss of MD-1 had the opposite effects. Similar results were observed for in vitro angiotensin II-induced neonatal rat cardiomyocyte hypertrophy. The antihypertrophic effects of MD-1 under hypertrophic stimuli were associated with the blockage of MEK-ERK 1/2 and NF-κB signalling. Blocking MEK-ERK 1/2 signalling with a pharmacological inhibitor (U0126) greatly attenuated the detrimental effects observed in MD-1 knockout cardiomyocytes exposed to angiotensin II stimuli. Similar results were observed by blocking NF-κB signalling with a pharmacological inhibitor (BAY11–7082). Our data indicate that MD-1 inhibits cardiac hypertrophy and suppresses cardiac dysfunction during the remodelling process, which is dependent on its modulation of the MEK-ERK 1/2 and NF-κB signalling pathways. Thus, MD-1 might be a novel target for the treatment of pathological cardiac hypertrophy. PMID:28165494

  11. Deubiquitinase BRCC36 protects heart against chronic pressure overload-induced cardiac remodeling in mice

    Institute of Scientific and Technical Information of China (English)

    LI Ru-jun; FANG Wei; ZHU Hua-jiang; ZHANG Feng-xia; XU Ou-fang; XU Li-juan; ZHANG Zhen-gang; GONG Kai-zheng

    2016-01-01

    Emerging evidence has indicated that BRCC 36-mediated K63-linked ubiquitination modification was involved in diverse cellular functions , including endocytosis , apoptosis and DNA damage repair .We previously showed that activation of cGMP/PKG pathway con-tributed to the binding of BRCC36 and the pro-fibrotic factor Smad3.The current study tested the hypothesis that BRCC 36 functions as a negative regulator of transforming growth factor-beta ( TGF-β)/Smad3 pathway and participates in cardiac remodeling .In isolated adult mouse cardiac fibroblasts , we have demonstrated that TGF-β1 treatment significantly increased the expression of BRCC 36.Over-expression BRCC36 suppressed TGF-β1-induced Smad3 phosphorylation, nuclear translocation, extracellular matrix molecular expres-sion and cell proliferation .On the contrary, silencing BRCC36 by transfection of adenovirus-carrying BRCC36 shRNA potentiated to enhance the pro-fibrotic effect of TGF-β.In vivo, under chronic pressure overload condition-induced by transverse aortic constriction , myocardial pro-survival protein Bcl-2 and Mcl-1 expression were significantly decreased and the pro-apoptosis protein Puma was in-creased.However, the cardiac-specific over-expression of BRCC36 significantly increased myocardial Bcl-2 and Mcl-1 and inhibited Puma expression .Interestingly , we also found that sustained pressure overload resulted in a significant myocardial DNA injury in wild type mice, which was characterized by the increase of γH2AX level.However, cardiac-specific BRCC36 over-expression significantly decreased the level of γH2AX in the pressure overloaded heart in the transgenic mice , while effectively enhanced myocardial RAD 51 expression, a marker of DNA damage repair.Furthermore, BRCC36 over-expression effectively attenuated TAC-induced cardiac fibro-sis and remodeling in the transgenic mice , compared with the wild type mice .Collectively , the results have suggested that BRCC 36 ef-fectively protected heart

  12. Impaired autophagy contributes to adverse cardiac remodeling in acute myocardial infarction.

    Directory of Open Access Journals (Sweden)

    Xiaoqian Wu

    Full Text Available OBJECTIVE: Autophagy is activated in ischemic heart diseases, but its dynamics and functional roles remain unclear and controversial. In this study, we investigated the dynamics and role of autophagy and the mechanism(s, if any, during postinfarction cardiac remodeling. METHODS AND RESULTS: Acute myocardial infarction (AMI was induced by ligating left anterior descending (LAD coronary artery. Autophagy was found to be induced sharply 12-24 hours after surgery by testing LC3 modification and Electron microscopy. P62 degradation in the infarct border zone was increased from day 0.5 to day 3, and however, decreased from day 5 until day 21 after LAD ligation. These results indicated that autophagy was induced in the acute phase of AMI, and however, impaired in the latter phase of AMI. To investigate the significance of the impaired autophagy in the latter phase of AMI, we treated the mice with Rapamycin (an autophagy enhancer, 2.0 mg/kg/day or 3-methyladenine (3MA, an autophagy inhibitor, 15 mg/kg/day one day after LAD ligation until the end of experiment. The results showed that Rapamycin attenuated, while 3MA exacerbated, postinfarction cardiac remodeling and dysfunction respectively. In addition, Rapamycin protected the H9C2 cells against oxygen glucose deprivation in vitro. Specifically, we found that Rapamycin attenuated NFκB activation after LAD ligation. And the inflammatory response in the acute stage of AMI was significantly restrained with Rapamycin treatment. In vitro, inhibition of NFκB restored autophagy in a negative reflex. CONCLUSION: Sustained myocardial ischemia impairs cardiomyocyte autophagy, which is an essential mechanism that protects against adverse cardiac remodeling. Augmenting autophagy could be a therapeutic strategy for acute myocardial infarction.

  13. AVE 3085, a novel endothelial nitric oxide synthase enhancer, attenuates cardiac remodeling in mice through the Smad signaling pathway.

    Science.gov (United States)

    Chen, Yili; Chen, Cong; Feng, Cong; Tang, Anli; Ma, Yuedong; He, Xin; Li, Yanhui; He, Jiangui; Dong, Yugang

    2015-03-15

    AVE 3085 is a novel endothelial nitric oxide synthase enhancer. Although AVE 3085 treatment has been shown to be effective in spontaneously restoring endothelial function in hypertensive rats, little is known about the effects and mechanisms of AVE 3085 with respect to cardiac remodeling. The present study was designed to examine the effects of AVE 3085 on cardiac remodeling and the mechanisms underlying the effects of this compound. Mice were subjected to aortic banding to induce cardiac remodeling and were then administered AVE 3085 (10 mg kg day(-1), orally) for 4 weeks. At the end of the treatment, the aortic banding-treated mice exhibited significant elevations in cardiac remodeling, characterized by an increase in left ventricular weight relative to body weight, an increase in the area of collagen deposition, an increase in the mean myocyte diameter, and increases in the gene expressions of the hypertrophic markers atrial natriuretic peptide (ANP) and β-MHC. These indexes were significantly decreased in the AVE 3085-treated mice. Furthermore, AVE 3085 treatment reduced the expression and activation of the Smad signaling pathway in the aortic banding-treated mice. Our data showed that AVE 3085 attenuated cardiac remodeling, and this effect was possibly mediated through the inhibition of Smad signaling.

  14. OSM mitigates post-infarction cardiac remodeling and dysfunction by up-regulating autophagy through Mst1 suppression.

    Science.gov (United States)

    Hu, Jianqiang; Zhang, Lei; Zhao, Zhijing; Zhang, Mingming; Lin, Jie; Wang, Jiaxing; Yu, Wenjun; Man, Wanrong; Li, Congye; Zhang, Rongqing; Gao, Erhe; Wang, Haichang; Sun, Dongdong

    2016-11-04

    The incidence and prevalence of heart failure (HF) in the world are rapidly rising possibly attributed to the worsened HF following myocardial infarction (MI) in recent years. Here we examined the effects of oncostatin M (OSM) on postinfarction cardiac remodeling and the underlying mechanisms involved. MI model was induced using left anterior descending coronary artery (LAD) ligation. In addition, cultured neonatal mouse cardiomyocytes were subjected to simulated MI. Our results revealed that OSM alleviated left ventricular remodeling, promoted cardiac function, restored mitochondrial cristae density and architecture disorders after 4weeks of MI. Enhanced autophagic flux was indicated in cardiomyocytes transduced with Ad-GFP -LC3 in the OSM treated group as compared with the MI group. OSM receptor Oβ knockout blocked the beneficial effects of OSM in postinfarction cardiac remodeling and cardiomyocytes autophagy. OSM pretreatment significantly alleviated left ventricular remodeling and dysfunction in Mst1 transgenic mice, while it failed to reverse further the postinfarction left ventricular dilatation and cardiac function in the Mst1 knockout mice. Our data revealed that OSM alleviated postinfarction cardiac remodeling and dysfunction by enhancing cardiomyocyte autophagy. OSM holds promise as a therapeutic target in treating HF after MI through Oβ receptor by inhibiting Mst1 phosphorylation.

  15. Sodium restriction modulates innate immunity and prevents cardiac remodeling in a rat model of metabolic syndrome.

    Science.gov (United States)

    Jover, Bernard; Reynes, Christelle; Rugale, Caroline; Reboul, Cyril; Jeanson, Laura; Tournier, Michel; Lajoix, Anne Dominique; Desmetz, Caroline

    2017-02-27

    In the view of the relationships between excessive sodium intake, immunity and target organ damage, we hypothesized that reduction in dietary sodium would be beneficial in the prevention of cardiac alterations through a restrained local immunity response in a rat model of metabolic syndrome. Sprague-Dawley rats were fed a 60% fructose diet with either a normal sodium (0.64% NaCl) or a low sodium content (<0.01% NaCl) for 8weeks. After 4weeks, rats were infused or not with angiotensin II (200ng.kg(-1).min(-1), sc) for 4weeks. Tail-cuff blood pressure was determined in conscious rats. Heart and left ventricle weight, cardiomyocyte size, and cardiac fibrosis were evaluated. We performed a transcriptomic analysis in order to identify differentially regulated cardiac mRNAs between normal and low sodium diets. We validated those results using qPCR and immunohistochemistry. Angiotensin II-induced blood pressure rise was blunted (~ 50%) in the low-sodium fed rats while cardiac hypertrophy and fibrosis were prevented. Transcriptomic analysis revealed 66 differentially regulated genes including 13 downregulated genes under the low sodium diet and implicated in the innate immune response. This was confirmed by reduced cardiac macrophages infiltration under the low sodium diet. Dietary sodium restriction prevents structural alterations of the heart of rats with fructose-induced insulin resistance and angiotensin II-hypertension. The reduction of cardiac inflammation and macrophage infiltration suggests that innate immunity has an important role in the beneficial effect of sodium restriction on cardiac remodeling.

  16. Berberine attenuates adverse left ventricular remodeling and cardiac dysfunction after acute myocardial infarction in rats: role of autophagy.

    Science.gov (United States)

    Zhang, Yao-Jun; Yang, Shao-Hua; Li, Ming-Hui; Iqbal, Javaid; Bourantas, Christos V; Mi, Qiong-Yu; Yu, Yi-Hui; Li, Jing-Jing; Zhao, Shu-Li; Tian, Nai-Liang; Chen, Shao-Liang

    2014-12-01

    The present study aimed to test the hypothesis that berberine, a plant-derived anti-oxidant, attenuates adverse left ventricular remodelling and improves cardiac function in a rat model of myocardial infarction (MI). Furthermore, the potential mechanisms that mediated the cardioprotective actions of berberine, in particular the effect on autophagy, were also investigated. Acute MI was induced by ligating the left anterior descending coronary artery of Sprague-Dawley rats. Cardiac function was assessed by transthoracic echocardiography. The protein activity/levels of autophagy related to signalling pathways (e.g. LC-3B, Beclin-1) were measured in myocardial tissue by immunohistochemical staining and western blot. Four weeks after MI, berberine significantly prevented cardiac dysfunction and adverse cardiac remodelling. MI rats treated with low dose berberine (10 mg/kg per day) showed higher left ventricular ejection fraction and fractional shortening than those treated with high-dose berberine (50 mg/kg per day). Both doses reduced interstitial fibrosis and post-MI adverse cardiac remodelling. The cardioprotective action of berberine was associated with increased LC-3B II and Beclin-1 expressions. Furthermore, cardioprotection with berberine was potentially related to p38 MAPK inhibition and phospho-Akt activation. The present in vivo study showed that berberine is effective in promoting autophagy, and subsequently attenuating left ventricular remodelling and cardiac dysfunction after MI. The potential underlying mechanism is augmentation of autophagy through inhibition of p38 MAPK and activation of phospho-Akt signalling pathways.

  17. Ischemia-reperfusion injury leads to distinct temporal cardiac remodeling in normal versus diabetic mice.

    Directory of Open Access Journals (Sweden)

    Megumi Eguchi

    Full Text Available Diabetes is associated with higher incidence of myocardial infarction (MI and increased propensity for subsequent events post-MI. Here we conducted a temporal analysis of the influence of diabetes on cardiac dysfunction and remodeling after ischemia reperfusion (IR injury in mice. Diabetes was induced using streptozotocin and IR performed by ligating the left anterior descending coronary artery for 30 min followed by reperfusion for up to 42 days. We first evaluated changes in cardiac function using echocardiography after 24 hours reperfusion and observed IR injury significantly decreased the systolic function, such as ejection fraction, fractional shortening and end systolic left ventricular volume (LVESV in both control and diabetic mice. The longitudinal systolic and diastolic strain rate were altered after IR, but there were no significant differences between diabetic mice and controls. However, a reduced ability to metabolize glucose was observed in the diabetic animals as determined by PET-CT scanning using 2-deoxy-2-((18Ffluoro-D-glucose. Interestingly, after 24 hours reperfusion diabetic mice showed a reduced infarct size and less apoptosis indicated by TUNEL analysis in heart sections. This may be explained by increased levels of autophagy detected in diabetic mice hearts. Similar increases in IR-induced macrophage infiltration detected by CD68 staining indicated no change in inflammation between control and diabetic mice. Over time, control mice subjected to IR developed mild left ventricular dilation whereas diabetic mice exhibited a decrease in both end diastolic left ventricular volume and LVESV with a decreased intraventricular space and thicker left ventricular wall, indicating concentric hypertrophy. This was associated with marked increases in fibrosis, indicted by Masson trichrome staining, of heart sections in diabetic IR group. In summary, we demonstrate that diabetes principally influences distinct IR-induced chronic changes

  18. Interaction of Left Ventricular Remodeling and Regional Dyssynchrony on Long-Term Prognosis after Cardiac Resynchronization Therapy

    DEFF Research Database (Denmark)

    Tayal, Bhupendar; Sogaard, Peter; Delgado-Montero, Antonia

    2017-01-01

    BACKGROUND: Left ventricular (LV) remodeling in heart failure (HF) manifested by chamber dilatation is associated with worse clinical outcomes. However, the impact of LV dilatation on the association of measures of dyssynchrony with long-term prognosis and resynchronization potential after cardiac...... was associated with the resynchronization ability of CRT. CONCLUSIONS: Patients with severe LV remodeling (EDVI ≥ 90 mL/m(2)) have a poor prognosis following CRT device implantation. This is most likely due to impaired resynchronization efficacy....

  19. Dysautonomia due to reduced cholinergic neurotransmission causes cardiac remodeling and heart failure.

    Science.gov (United States)

    Lara, Aline; Damasceno, Denis D; Pires, Rita; Gros, Robert; Gomes, Enéas R; Gavioli, Mariana; Lima, Ricardo F; Guimarães, Diogo; Lima, Patricia; Bueno, Carlos Roberto; Vasconcelos, Anilton; Roman-Campos, Danilo; Menezes, Cristiane A S; Sirvente, Raquel A; Salemi, Vera M; Mady, Charles; Caron, Marc G; Ferreira, Anderson J; Brum, Patricia C; Resende, Rodrigo R; Cruz, Jader S; Gomez, Marcus Vinicius; Prado, Vania F; de Almeida, Alvair P; Prado, Marco A M; Guatimosim, Silvia

    2010-04-01

    Overwhelming evidence supports the importance of the sympathetic nervous system in heart failure. In contrast, much less is known about the role of failing cholinergic neurotransmission in cardiac disease. By using a unique genetically modified mouse line with reduced expression of the vesicular acetylcholine transporter (VAChT) and consequently decreased release of acetylcholine, we investigated the consequences of altered cholinergic tone for cardiac function. M-mode echocardiography, hemodynamic experiments, analysis of isolated perfused hearts, and measurements of cardiomyocyte contraction indicated that VAChT mutant mice have decreased left ventricle function associated with altered calcium handling. Gene expression was analyzed by quantitative reverse transcriptase PCR and Western blotting, and the results indicated that VAChT mutant mice have profound cardiac remodeling and reactivation of the fetal gene program. This phenotype was attributable to reduced cholinergic tone, since administration of the cholinesterase inhibitor pyridostigmine for 2 weeks reversed the cardiac phenotype in mutant mice. Our findings provide direct evidence that decreased cholinergic neurotransmission and underlying autonomic imbalance cause plastic alterations that contribute to heart dysfunction.

  20. Time Course of Atrophic Remodeling: Effects of Exercise on Cardiac Morpology and Function

    Science.gov (United States)

    Scott, J. M.; Martin, D.; Caine, T.; Matz, T.; Ploutz-Snyder, L. L.

    2014-01-01

    Early and consistent evaluation of cardiac morphology and function throughout an atrophic stimulus is critically important for the design and optimization of interventions. Exercise training is one intervention that has been shown to confer favorable improvements in LV mass and function during unloading. However, the format and intensity of exercise required to induce optimal cardiac improvements has not been investigated. PURPOSE: This randomized, controlled trial was designed to 1) comprehensively characterize the time course of unloading-induced morpho-functional remodeling, and 2) examine the effects of high intensity exercise training on cardiac structural and functional parameters during unloading. METHODS: Twenty six subjects completed 70 days of head down tilt bed rest (HDBR): 17 were randomized to exercise training (ExBR) and 9 remained sedentary. Exercise consisted of integrated high intensity, continuous, and resistance exercise. We assessed cardiac morphology (left ventricular mass; LVM) and function (speckle-tracking assessment of longitudinal, radial, and circumferential strain and twist) before (BR-2), during (BR7,21,31,70), and following (BR+0, +3) HDBR. Cardiorespiratory fitness (VO2max) was evaluated before (BR- 3), during (BR4,25,46,68) and following (BR+0) HDBR. RESULTS: Sedentary HDBR resulted in a progressive decline in LVM, longitudinal, radial, and circumferential strain, and an increase in twist. ExBR mitigated decreases in LVM and function. Change in twist was significantly related to change in VO2max (R=0.68, premodeling.

  1. Pioglitazone alleviates cardiac and vascular remodelling and improves survival in monocrotaline induced pulmonary arterial hypertension.

    Science.gov (United States)

    Behringer, Arnica; Trappiel, Manuela; Berghausen, Eva Maria; Ten Freyhaus, Henrik; Wellnhofer, Ernst; Odenthal, Margarete; Blaschke, Florian; Er, Fikret; Gassanov, Natig; Rosenkranz, Stephan; Baldus, Stephan; Kappert, Kai; Caglayan, Evren

    2016-04-01

    Pulmonary arterial hypertension (PAH) is a fatal disease with limited therapeutic options. Pathophysiological changes comprise obliterative vascular remodelling of small pulmonary arteries, elevated mean pulmonary arterial systolic pressure (PASP) due to elevated resistance of pulmonary vasculature, adverse right ventricular remodelling, and heart failure. Recent findings also indicate a role of increased inflammation and insulin resistance underlying the development of PAH. We hypothesized that treatment of this condition with the peroxisome proliferator-activated receptor-γ (PPARγ) activator pioglitazone, known to regulate the expression of different genes addressing insulin resistance, inflammatory changes, and vascular remodelling, could be a beneficial approach. PAH was induced in adult rats by a single subcutaneous injection of monocrotaline (MCT). Pioglitazone was administered for 2 weeks starting 3 weeks after MCT-injection. At day 35, hemodynamics, organ weights, and -indices were measured. We performed morphological and molecular characterization of the pulmonary vasculature, including analysis of the degree of muscularization, proliferation rates, and medial wall thickness of the small pulmonary arteries. Furthermore, markers of cardiac injury, collagen content, and cardiomyocyte size were analyzed. Survival rates were monitored throughout the experimental period. Pioglitazone treatment improved survival, reduced PASP, muscularization of small pulmonary arteries, and medial wall thickness. Further, MCT-induced right ventricular hypertrophy and fibrosis were attenuated. This was accompanied with reduced cardiac expression of brain natriuretic peptide, as well as decreased cardiomyocyte size. Finally, pulmonary macrophage content and osteopontin gene expression were attenuated. Based on the beneficial impact of pioglitazone, activation of PPARγ might be a promising treatment option in PAH.

  2. Aerobic Training after Myocardial Infarction: Remodeling Evaluated by Cardiac Magnetic Resonance

    Energy Technology Data Exchange (ETDEWEB)

    Izeli, Nataly Lino; Santos, Aurélia Juliana dos; Crescêncio, Júlio César; Gonçalves, Ana Clara Campagnolo Real; Papa, Valéria; Marques, Fabiana [Divisão de Cardiologia do Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto - USP, Ribeirão Preto, SP (Brazil); Pazin-Filho, Antônio [Divisão de Emergência da Faculdade de Medicina de Ribeirão Preto - USP, Ribeirão Preto, SP (Brazil); Gallo-Júnior, Lourenço; Schmidt, André, E-mail: aschmidt@fmrp.usp.br [Divisão de Cardiologia do Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto - USP, Ribeirão Preto, SP (Brazil)

    2016-04-15

    Numerous studies show the benefits of exercise training after myocardial infarction (MI). Nevertheless, the effects on function and remodeling are still controversial. To evaluate, in patients after (MI), the effects of aerobic exercise of moderate intensity on ventricular remodeling by cardiac magnetic resonance imaging (CMR). 26 male patients, 52.9 ± 7.9 years, after a first MI, were assigned to groups: trained group (TG), 18; and control group (CG), 8. The TG performed supervised aerobic exercise on treadmill twice a week, and unsupervised sessions on 2 additional days per week, for at least 3 months. Laboratory tests, anthropometric measurements, resting heart rate (HR), exercise test, and CMR were conducted at baseline and follow-up. The TG showed a 10.8% reduction in fasting blood glucose (p = 0.01), and a 7.3-bpm reduction in resting HR in both sitting and supine positions (p < 0.0001). There was an increase in oxygen uptake only in the TG (35.4 ± 8.1 to 49.1 ± 9.6 mL/kg/min, p < 0.0001). There was a statistically significant decrease in the TG left ventricular mass (LVmass) (128.7 ± 38.9 to 117.2 ± 27.2 g, p = 0.0032). There were no statistically significant changes in the values of left ventricular end-diastolic volume (LVEDV) and ejection fraction in the groups. The LVmass/EDV ratio demonstrated a statistically significant positive remodeling in the TG (p = 0.015). Aerobic exercise of moderate intensity improved physical capacity and other cardiovascular variables. A positive remodeling was identified in the TG, where a left ventricular diastolic dimension increase was associated with LVmass reduction.

  3. Electrical and structural remodeling: role in the genesis and maintenance of atrial fibrillation.

    Science.gov (United States)

    Schoonderwoerd, Bas A; Van Gelder, Isabelle C; Van Veldhuisen, Dirk J; Van den Berg, Maarten P; Crijns, Harry J G M

    2005-01-01

    Atrial fibrillation (AF) and congestive heart failure (CHF) are 2 frequently encountered conditions in clinical practice. Both lead to changes in atrial function and structure, an array of processes known as atrial remodeling. This review provides an overview of ionic, electrical, contractile, neurohumoral, and structural atrial changes responsible for initiation and maintenance of AF. In the last decade, many studies have evaluated atrial remodeling due to AF or CHF. Both conditions often coexist, which makes it difficult to distinguish the contribution of each. Because of atrial stretch in the setting of hypertension or CHF, atrial remodeling frequently occurs long before AF arises. Alternatively, AF may lead to electrical remodeling, that is, shortening of refractoriness due to the high atrial rate itself. In many experimental AF or rapid atrial pacing studies, the ventricular rate was uncontrolled. In those studies, atrial stretch due to CHF may have interfered with the high atrial rate to produce a mixed type of electrical and structural remodeling. Other studies have dissected the individual role of AF or atrial tachycardia from the role CHF plays in atrial remodeling. Atrial fibrillation itself does not lead to structural remodeling, whereas this is frequently produced by hypertension or CHF, even in the absence of AF. Primary and secondary prevention programs should tailor treatment to the various types of remodeling.

  4. Effects of renal sympathetic denervation on post-myocardial infarction cardiac remodeling in rats.

    Directory of Open Access Journals (Sweden)

    Jialu Hu

    Full Text Available OBJECTIVE: To investigate the therapeutic effects of renal denervation (RD on post- myocardial infarction (MI cardiac remodeling in rats, the most optimal time for intervention and the sustainability of these effects. METHODS: One hundred SPF male Wistar rats were randomly assigned to N group (Normal, n=10, MI group(MI, n=20,RD group (RD, n=10, RD3+MI (MI three days after RD, n=20, MI1+RD (RD one day after MI, n=20, MI7+RD (RD seven days after MI, n=20. MI was produced through thoracotomic ligation of the anterior descending artery. RD was performed through laparotomic stripping of the renal arteriovenous adventitial sympathetic nerve. Left ventricular function, hemodynamics, plasma BNP, urine volume, urine sodium excretion and other indicators were measured four weeks after MI. RESULTS: (1 The left ventricular function of the MI group significantly declined (EF<40%, plasma BNP was elevated, urine output was significantly reduced, and 24-hour urine sodium excretion was significantly reduced. (2 Denervation can be achieved by surgically stripping the arteriovenous adventitia, approximately 3 mm from the abdominal aorta. (3 In rats with RD3+MI, MI1+RD and MI7+RD, compared with MI rats respectively, the LVEF was significantly improved (75 ± 8.4%,69 ± 3.8%,73 ± 5.5%, hemodynamic indicators were significantly improved, plasma BNP was significantly decreased, and the urine output was significantly increased (21.3 ± 5 ml,23.8 ± 5.4 ml,25.2 ± 8.7 ml. However, the urinary sodium excretion also increased but without significant difference. CONCLUSIONS: RD has preventive and therapeutic effects on post-MI cardiac remodeling.These effects can be sustained for at least four weeks, but there were no significant differences between denervation procedures performed at different times in the course of illness. Cardiac function, hemodynamics, urine volume and urine sodium excretion in normal rats were not affected by RD.

  5. N-acetylcysteine attenuates the development of cardiac fibrosis and remodeling in a mouse model of heart failure.

    Science.gov (United States)

    Giam, Beverly; Chu, Po-Yin; Kuruppu, Sanjaya; Smith, A Ian; Horlock, Duncan; Kiriazis, Helen; Du, Xiao-Jun; Kaye, David M; Rajapakse, Niwanthi W

    2016-04-01

    Oxidative stress plays a central role in the pathogenesis of heart failure. We aimed to determine whether the antioxidantN-acetylcysteine can attenuate cardiac fibrosis and remodeling in a mouse model of heart failure. Minipumps were implanted subcutaneously in wild-type mice (n = 20) and mice with cardiomyopathy secondary to cardiac specific overexpression of mammalian sterile 20-like kinase 1 (MST-1;n = 18) to administerN-acetylcysteine (40 mg/kg per day) or saline for a period of 8 weeks. At the end of this period, cardiac remodeling and function was assessed via echocardiography. Fibrosis, oxidative stress, and expression of collagen types I andIIIwere quantified in heart tissues. Cardiac perivascular and interstitial fibrosis were greater by 114% and 209%, respectively, inMST-1 compared to wild type (P ≤ 0.001). InMST-1 mice administeredN-acetylcysteine, perivascular and interstitial fibrosis were 40% and 57% less, respectively, compared to those treated with saline (P ≤ 0. 03). Cardiac oxidative stress was 119% greater inMST-1 than in wild type (P cardiac fibrosis and related remodeling in the setting of heart failure potentially by reducing oxidative stress. This study provides the basis to investigate the role ofN-acetylcysteine in chronic heart failure.

  6. Cardiac remodeling associated with protein increase and lipid accumulation in early-stage chronic kidney disease in rats.

    Science.gov (United States)

    Kuwahara, Mieko; Bannai, Kenji; Segawa, Hiroko; Miyamoto, Ken-ichi; Yamato, Hideyuki

    2014-09-01

    Chronic kidney disease (CKD) is associated with increased risks of cardiovascular morbidity and mortality. Cardiac remodeling including myocardial fibrosis and hypertrophy is frequently observed in CKD patients. In this study, we investigate the mechanism involved in cardiac hypertrophy associated with CKD using a rat model, by morphological and chemical component changes of the hypertrophic and non-hypertrophic hearts. Sprague-Dawley rats were 4/5 nephrectomized (Nx) at 11 weeks of age and assigned to no treatment and treatment with AST-120, which was reported to affect the cardiac damage, at 18 weeks of age. At 26 weeks of age, the rats were euthanized under anesthesia, and biochemical tests as well as analysis of cardiac condition were performed by histological and spectrophotometric methods. Cardiac hypertrophy and CKD were observed in 4/5 Nx rats even though vascular calcification and myocardial fibrosis were not detected. The increasing myocardial protein was confirmed in hypertrophic hearts by infrared spectroscopy. The absorption of amide I and other protein bands in hypertrophic hearts increased at the same position as in normal cardiac absorption. Infrared spectra also showed that lipid accumulation was also detected in hypertrophic heart. Conversely, the absorptions of protein were obviously reduced in the myocardium of non-hypertrophic heart with CKD compared to that of hypertrophic heart. The lipid associated absorption was also decreased in non-hypertrophic heart. Our results suggest that cardiac remodeling associated with relatively early-stage CKD may be suppressed by reducing increased myocardial protein and ameliorating cardiac lipid load.

  7. Optimization of electrical stimulation parameters for cardiac tissue engineering.

    Science.gov (United States)

    Tandon, Nina; Marsano, Anna; Maidhof, Robert; Wan, Leo; Park, Hyoungshin; Vunjak-Novakovic, Gordana

    2011-06-01

    In vitro application of pulsatile electrical stimulation to neonatal rat cardiomyocytes cultured on polymer scaffolds has been shown to improve the functional assembly of cells into contractile engineered cardiac tissues. However, to date, the conditions of electrical stimulation have not been optimized. We have systematically varied the electrode material, amplitude and frequency of stimulation to determine the conditions that are optimal for cardiac tissue engineering. Carbon electrodes, exhibiting the highest charge-injection capacity and producing cardiac tissues with the best structural and contractile properties, were thus used in tissue engineering studies. Engineered cardiac tissues stimulated at 3 V/cm amplitude and 3 Hz frequency had the highest tissue density, the highest concentrations of cardiac troponin-I and connexin-43 and the best-developed contractile behaviour. These findings contribute to defining bioreactor design specifications and electrical stimulation regime for cardiac tissue engineering.

  8. Atorvastatin improves cardiac function and remodeling in chronic non-ischemic heart failure: A clinical and pre-clinical study

    Directory of Open Access Journals (Sweden)

    Ibrahim Elmadbouh

    2015-12-01

    Conclusions: Atorvastatin with standard CHF therapy improved cardiac function and remodeling. Cardio-protective “pleiotropic” actions of atorvastatin are anti-inflammatory, anti-fibrotic and anti-oxidative. Thus, atorvastatin has a potential therapeutic value in the management of CHF patients.

  9. Relationship Between Reverse Remodeling and Cardiopulmonary Exercise Capacity in Heart Failure Patients Undergoing Cardiac Resynchronization Therapy

    DEFF Research Database (Denmark)

    Mastenbroek, Mirjam H; Sant, Jetske Van't; Versteeg, Henneke

    2016-01-01

    -defibrillator (mean age 65 ± 11; 73% male) underwent echocardiography and cardiopulmonary exercise testing (CPX) before implantation (baseline) and 6 months after implantation. At baseline, patients also completed a set of questionnaires measuring mental and physical health. The association between echocardiographic......BACKGROUND: Studies on the relationship between left ventricular reverse remodeling and cardiopulmonary exercise capacity in heart failure patients undergoing cardiac resynchronization therapy (CRT) are scarce and inconclusive. METHODS AND RESULTS: Eighty-four patients with a 1st-time CRT...... response (left ventricular end-systolic volume decrease ≥15%) and a comprehensive set of CPX results was examined. Echocardiographic responders (54%) demonstrated higher peak oxygen consumption and better exercise performance than nonresponders at baseline and at 6-month follow-up. Furthermore, only...

  10. Myocardial scaffold-based cardiac tissue engineering: application of coordinated mechanical and electrical stimulations.

    Science.gov (United States)

    Wang, Bo; Wang, Guangjun; To, Filip; Butler, J Ryan; Claude, Andrew; McLaughlin, Ronald M; Williams, Lakiesha N; de Jongh Curry, Amy L; Liao, Jun

    2013-09-03

    Recently, we developed an optimal decellularization protocol to generate 3D porcine myocardial scaffolds, which preserve the natural extracellular matrix structure, mechanical anisotropy, and vasculature templates and also show good cell recellularization and differentiation potential. In this study, a multistimulation bioreactor was built to provide coordinated mechanical and electrical stimulation for facilitating stem cell differentiation and cardiac construct development. The acellular myocardial scaffolds were seeded with mesenchymal stem cells (10(6) cells/mL) by needle injection and subjected to 5-azacytidine treatment (3 μmol/L, 24 h) and various bioreactor conditioning protocols. We found that after 2 days of culturing with mechanical (20% strain) and electrical stimulation (5 V, 1 Hz), high cell density and good cell viability were observed in the reseeded scaffold. Immunofluorescence staining demonstrated that the differentiated cells showed a cardiomyocyte-like phenotype by expressing sarcomeric α-actinin, myosin heavy chain, cardiac troponin T, connexin-43, and N-cadherin. Biaxial mechanical testing demonstrated that positive tissue remodeling took place after 2 days of bioreactor conditioning (20% strain + 5 V, 1 Hz); passive mechanical properties of the 2 day and 4 day tissue constructs were comparable to those of the tissue constructs produced by stirring reseeding followed by 2 weeks of static culturing, implying the effectiveness and efficiency of the coordinated simulations in promoting tissue remodeling. In short, the synergistic stimulations might be beneficial not only for the quality of cardiac construct development but also for patients by reducing the waiting time in future clinical scenarios.

  11. Cardiac remodeling following percutaneous mitral valve repair. Initial results assessed by cardiovascular magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Radunski, U.K [University Heart Center, Hamburg (Germany). Cardiology; Franzen, O. [Rigshospitalet, Copenhagen (Denmark). Cardiology; Barmeyer, A. [Klinikum Dortmund (Germany). Kardiologie; and others

    2014-10-15

    Percutaneous mitral valve repair with the MitraClip device (Abbott Vascular, Redwood City, California, USA) is a novel therapeutic option in patients with mitral regurgitation. This study evaluated the feasibility of cardiac volume measurements by cardiovascular magnetic resonance imaging (CMR) to assess reverse myocardial remodeling in patients after MitraClip implantation. 12 patients underwent CMR at baseline (BL) before and at 6 months follow-up (FU) after MitraClip implantation. Cine-CMR was performed in short- and long-axes for the assessment of left ventricular (LV), right ventricular (RV) and left atrial (LA) volumes. Assessment of endocardial contours was not compromised by the device-related artifact. No significant differences in observer variances were observed for LV, RV and LA volume measurements between BL and FU. LV end-diastolic (median 127 [IQR 96-150] vs. 112 [86-150] ml/m{sup 2}; p=0.03) and LV end-systolic (82 [54-91] vs. 69 [48-99] ml/m{sup 2}; p=0.03) volume indices decreased significantly from BL to FU. No significant differences were found for RV end-diastolic (94 [75-103] vs. 99 [77-123] ml/m{sup 2}; p=0.91), RV end-systolic (48 [42-80] vs. 51 [40-81] ml/m{sup 2}; p=0.48), and LA (87 [55-124] vs. 92 [48-137]R ml/m{sup 2}; p=0.20) volume indices between BL and FU. CMR enables the assessment of cardiac volumes in patients after MitraClip implantation. Our CMR findings indicate that percutaneous mitral valve repair results in reverse LV but not in RV or LA remodeling.

  12. Vagus nerve stimulation mitigates intrinsic cardiac neuronal and adverse myocyte remodeling postmyocardial infarction.

    Science.gov (United States)

    Beaumont, Eric; Southerland, Elizabeth M; Hardwick, Jean C; Wright, Gary L; Ryan, Shannon; Li, Ying; KenKnight, Bruce H; Armour, J Andrew; Ardell, Jeffrey L

    2015-10-01

    This paper aims to determine whether chronic vagus nerve stimulation (VNS) mitigates myocardial infarction (MI)-induced remodeling of the intrinsic cardiac nervous system (ICNS), along with the cardiac tissue it regulates. Guinea pigs underwent VNS implantation on the right cervical vagus. Two weeks later, MI was produced by ligating the ventral descending coronary artery. VNS stimulation started 7 days post-MI (20 Hz, 0.9 ± 0.2 mA, 14 s on, 48 s off; VNS-MI, n = 7) and was compared with time-matched MI animals with sham VNS (MI n = 7) vs. untreated controls (n = 8). Echocardiograms were performed before and at 90 days post-MI. At termination, IC neuronal intracellular voltage recordings were obtained from whole-mount neuronal plexuses. MI increased left ventricular end systolic volume (LVESV) 30% (P = 0.027) and reduced LV ejection fraction (LVEF) 6.5% (P < 0.001) at 90 days post-MI compared with baseline. In the VNS-MI group, LVESV and LVEF did not differ from baseline. IC neurons showed depolarization of resting membrane potentials and increased input resistance in MI compared with VNS-MI and sham controls (P < 0.05). Neuronal excitability and sensitivity to norepinephrine increased in MI and VNS-MI groups compared with controls (P < 0.05). Synaptic efficacy, as determined by evoked responses to stimulating input axons, was reduced in VNS-MI compared with MI or controls (P < 0.05). VNS induced changes in myocytes, consistent with enhanced glycogenolysis, and blunted the MI-induced increase in the proapoptotic Bcl-2-associated X protein (P < 0.05). VNS mitigates MI-induced remodeling of the ICNS, correspondingly preserving ventricular function via both neural and cardiomyocyte-dependent actions.

  13. Maternal hypoxia alters matrix metalloproteinase expression patterns and causes cardiac remodeling in fetal and neonatal rats.

    Science.gov (United States)

    Tong, Wenni; Xue, Qin; Li, Yong; Zhang, Lubo

    2011-11-01

    Fetal hypoxia leads to progressive cardiac remodeling in rat offspring. The present study tested the hypothesis that maternal hypoxia results in reprogramming of matrix metalloproteinase (MMP) expression patterns and fibrillar collagen matrix in the developing heart. Pregnant rats were treated with normoxia or hypoxia (10.5% O(2)) from day 15 to 21 of gestation. Hearts were isolated from 21-day fetuses (E21) and postnatal day 7 pups (PD7). Maternal hypoxia caused a decrease in the body weight of both E21 and PD7. The heart-to-body weight ratio was increased in E21 but not in PD7. Left ventricular myocardium wall thickness and cardiomyocyte proliferation were significantly decreased in both fetal and neonatal hearts. Hypoxia had no effect on fibrillar collagen content in the fetal heart, but significantly increased the collagen content in the neonatal heart. Western blotting revealed that maternal hypoxia significantly increased collagen I, but not collagen III, levels in the neonatal heart. Maternal hypoxia decreased MMP-1 but increased MMP-13 and membrane type (MT)1-MMP in the fetal heart. In the neonatal heart, MMP-1 and MMP-13 were significantly increased. Active MMP-2 and MMP-9 levels and activities were not altered in either fetal or neonatal hearts. Hypoxia significantly increased tissue inhibitors of metalloproteinase (TIMP)-3 and TIMP-4 in both fetal and neonatal hearts. In contrast, TIMP-1 and TIMP-2 were not affected. The results demonstrate that in utero hypoxia reprograms the expression patterns of MMPs and TIMPs and causes cardiac tissue remodeling with the increased collagen deposition in the developing heart.

  14. Gender-Based Differences in Cardiac Remodeling and ILK Expression after Myocardial Infarction

    Directory of Open Access Journals (Sweden)

    Renato Rodrigues Sofia

    2014-08-01

    Full Text Available Background: Gender can influence post-infarction cardiac remodeling. Objective: To evaluate whether gender influences left ventricular (LV remodeling and integrin-linked kinase (ILK after myocardial infarction (MI. Methods: Female and male Wistar rats were assigned to one of three groups: sham, moderate MI (size: 20-39% of LV area, and large MI (size: ≥40% of LV area. MI was induced by coronary occlusion, and echocardiographic analysis was performed after six weeks to evaluate MI size as well as LV morphology and function. Real-time RT-PCR and Western blot were used to quantify ILK in the myocardium. Results: MI size was similar between genders. MI resulted in systolic dysfunction and enlargement of end-diastolic as well as end-systolic dimension of LV as a function of necrotic area size in both genders. Female rats with large MI showed a lower diastolic and systolic dilatation than the respective male rats; however, LV dysfunction was similar between genders. Gene and protein levels of ILK were increased in female rats with moderate and large infarctions, but only male rats with large infarctions showed an altered ILK mRNA level. A negative linear correlation was evident between LV dimensions and ILK expression in female rats with large MI. Conclusions: Post-MI ILK expression is altered in a gender-specific manner, and higher ILK levels found in females may be sufficient to improve LV geometry but not LV function.

  15. Gender-Based Differences in Cardiac Remodeling and ILK Expression after Myocardial Infarction

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    Sofia, Renato Rodrigues [Programa de Pós-graduação em Ciências da Reabilitação - Universidade Nove de Julho (Uninove), São Paulo, SP (Brazil); Departamento de Cardiologia - Universidade Federal de São Paulo, São Paulo, SP (Brazil); Serra, Andrey Jorge, E-mail: andreyserra@gmail.com; Silva, Jose Antonio Jr [Programa de Pós-graduação em Ciências da Reabilitação - Universidade Nove de Julho (Uninove), São Paulo, SP (Brazil); Antonio, Ednei Luiz [Departamento de Cardiologia - Universidade Federal de São Paulo, São Paulo, SP (Brazil); Manchini, Martha Trindade [Programa de Pós-graduação em Ciências da Reabilitação - Universidade Nove de Julho (Uninove), São Paulo, SP (Brazil); Oliveira, Fernanda Aparecida Alves de [Departamento de Cardiologia - Universidade Federal de São Paulo, São Paulo, SP (Brazil); Teixeira, Vicente Paulo Castro [Departamento de Patologia - Universidade Federal de São Paulo, São Paulo, SP (Brazil); Tucci, Paulo José Ferreira [Departamento de Cardiologia - Universidade Federal de São Paulo, São Paulo, SP (Brazil)

    2014-08-15

    Gender can influence post-infarction cardiac remodeling. To evaluate whether gender influences left ventricular (LV) remodeling and integrin-linked kinase (ILK) after myocardial infarction (MI). Female and male Wistar rats were assigned to one of three groups: sham, moderate MI (size: 20-39% of LV area), and large MI (size: ≥40% of LV area). MI was induced by coronary occlusion, and echocardiographic analysis was performed after six weeks to evaluate MI size as well as LV morphology and function. Real-time RT-PCR and Western blot were used to quantify ILK in the myocardium. MI size was similar between genders. MI resulted in systolic dysfunction and enlargement of end-diastolic as well as end-systolic dimension of LV as a function of necrotic area size in both genders. Female rats with large MI showed a lower diastolic and systolic dilatation than the respective male rats; however, LV dysfunction was similar between genders. Gene and protein levels of ILK were increased in female rats with moderate and large infarctions, but only male rats with large infarctions showed an altered ILK mRNA level. A negative linear correlation was evident between LV dimensions and ILK expression in female rats with large MI. Post-MI ILK expression is altered in a gender-specific manner, and higher ILK levels found in females may be sufficient to improve LV geometry but not LV function.

  16. Effects of Losartan on acute atrial electrical remodeling

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    李悦; 李为民; 薛竟宜; 韩薇; 杨树森; 谷宏越

    2004-01-01

    Background Atrial electrical remodeling (AER) contributes to the maintainance of atrial fibrillation (AF). This study was to compare the effects of Losartan with those of Diltiazem on tachycardia-induced acute AER in rabbits.Methods Twenty-one rabbits paced with maximal atrial capture rate for 3 hours in the right atrium (RA) were randomly divided into saline group, Diltiazem group and Losartan group. After autonomic blockage, we measured atrial effective refractory period (AERP), AERP rate adapting feature, AERP dispersion and RA conduction time at basic cycle lengths (BCLs) of 200 ms and 150 ms at baseline, 0.5 hour, 1 hour, 2 and 3 hours after rapid atrial pacing. Results In the saline group, there was a prompt decrease in AERP as a result of rapid atrial pacing, and AERP200 and AERP150 were shortened sharply within 0.5 hour of pacing (30.2±10.5 ms and 24.1±9.1 ms, respectively). The AERP did not change dramatically in the Diltiazem and Losartan groups. In the saline group, the value of (AERP200-AERP150)/50 ms in high RA was 0.17±0.08 at baseline and became significantly smaller at 0.5 hour (0.08±0.06), 1 hour (0.09±0.06), 2 hours (0.08±0.04) and 3 hours (0.09±0.05) (all P<0.05), suggesting a reduction of rate adaptation of AERP. The value of (AERP200-AERP150)/50 ms in high RA did not change during the 3 hours of pacing in both Diltiazem and Losartan groups. In the saline group, AERP dispersion increased significantly at 2 and 3 hours (P<0.05). However, Diltiazem could not prevent the increase of AERP dispersion at 3 hours (P<0.05). During Losartan infusion, the AERP dispersion was no longer increased after rapid atrial pacing. There was no significant difference in RA conduction time among the three groups.Conclusion Like calcium antagonist Diltiazem, Losartan could prevent AERP shortening and preserve rate adaptation of AERP after rapid atrial pacing. Losartan is more effective than Diltiazem in inhibiting the increase of AERP dispersion.

  17. Transcatheter Closure of Atrial Septal Defects Improves Cardiac Remodeling and Function of Adult Patients with Permanent Atrial Fibrillation

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    Liang Chen; Yuan Bai; Fei-Yu Wang; Zhi-Gang Zhang; Xing-Hua Shan; Tao Chen; Xian-Xian Zhao

    2015-01-01

    Background:Permanent atrial fibrillation (AF) is the most common form of dysrhythmia associated with atrial septal defects (ASDs) in patients older than 40 years.However,little is known about cardiac remodeling after transcatheter closure in patients with permanent AF.This study was designed to compare cardiac events and remodeling effects after transcatheter closure in such patients.Methods:Clinical data of 289 adult patients older than 40 years who underwent ASD closure at our center were analyzed retrospectively.Of them,63 patients with permanent AF were assigned to the case group,and the other 226 patients without permanent AF were assigned to the control group.Cardiac events and changes in left and right cardiac cavity dimensions before the procedure and 6 months after the procedure were compared between the two groups.Results:Patients in the case group were significantly older than those in the control group.The right ventricular (RV) volume and right atrial (RA) volume were decreased significantly in both the groups during a median follow-up period of 6 months after closure (P < 0.001).The left atrial dimensions,left ventricular end-systolic dimensions,left ventricular end-diastolic dimensions and left ventricular ejection fraction showed no significant change before and after the procedure in both the groups.Changes of the RV volume and RA volume in the case group were significantly smaller than those in the control group (P =0.005 and P < 0.001).The New York Heart Association cardiac function was improved in both the groups during the 6 months follow-up period.Conclusions:The transcatheter closure of ASD can improve the cardiac remodeling and cardiac function in patients with or without AF.

  18. Transcatheter Closure of Atrial Septal Defects Improves Cardiac Remodeling and Function of Adult Patients with Permanent Atrial Fibrillation

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    Liang Chen

    2015-01-01

    Full Text Available Background: Permanent atrial fibrillation (AF is the most common form of dysrhythmia associated with atrial septal defects (ASDs in patients older than 40 years. However, little is known about cardiac remodeling after transcatheter closure in patients with permanent AF. This study was designed to compare cardiac events and remodeling effects after transcatheter closure in such patients. Methods: Clinical data of 289 adult patients older than 40 years who underwent ASD closure at our center were analyzed retrospectively. Of them, 63 patients with permanent AF were assigned to the case group, and the other 226 patients without permanent AF were assigned to the control group. Cardiac events and changes in left and right cardiac cavity dimensions before the procedure and 6 months after the procedure were compared between the two groups. Results: Patients in the case group were significantly older than those in the control group. The right ventricular (RV volume and right atrial (RA volume were decreased significantly in both the groups during a median follow-up period of 6 months after closure (P < 0.001. The left atrial dimensions, left ventricular end-systolic dimensions, left ventricular end-diastolic dimensions and left ventricular ejection fraction showed no significant change before and after the procedure in both the groups. Changes of the RV volume and RA volume in the case group were significantly smaller than those in the control group (P = 0.005 and P < 0.001. The New York Heart Association cardiac function was improved in both the groups during the 6 months follow-up period. Conclusions: The transcatheter closure of ASD can improve the cardiac remodeling and cardiac function in patients with or without AF.

  19. Ongoing controversies surrounding cardiac remodeling: is it black and white-or rather fifty shades of gray?

    Science.gov (United States)

    Spaich, Sebastian; Katus, Hugo A; Backs, Johannes

    2015-01-01

    Cardiac remodeling describes the heart's multimodal response to a myriad of external or intrinsic stimuli and stressors most of which are probably only incompletely elucidated to date. Over many years the signaling molecules involved in these remodeling processes have been dichotomized according to a classic antagonistic view of black and white, i.e., attributed either a solely maladaptive or entirely beneficial character. By dissecting controversies, recent developments and shifts in perspective surrounding the three major cardiac signaling molecules calcineurin (Cn), protein kinase A (PKA) and calcium/calmodulin-dependent kinase II (CaMKII), this review challenges this dualistic view and advocates the nature and dignity of each of these key mediators of cardiac remodeling as a multilayered, highly context-sensitive and sophisticated continuum that can be markedly swayed and influenced by a multitude of environmental factors and crosstalk mechanisms. Furthermore this review delineates the importance and essential contributions of degradation and proteolysis to cardiac plasticity and homeostasis and finally aims to integrate the various aspects of protein synthesis and turnover into a comprehensive picture.

  20. Ongoing controversies surrounding cardiac remodeling: is it black and white – or rather fifty shades of grey?

    Directory of Open Access Journals (Sweden)

    Sebastian eSpaich

    2015-07-01

    Full Text Available Cardiac remodeling describes the heart’s multimodal response to a myriad of external or intrinsic stimuli and stressors most of which are probably only incompletely elucidated to date. Over many years the signaling molecules involved in these remodeling processes have been dichotomized according to a classic antagonistic view of black and white, i.e. attributed either a solely maladaptive or entirely beneficial character. By dissecting controversies, recent developments and shifts in perspective surrounding the 3 major cardiac signaling molecules calcineurin (Cn, protein kinase A (PKA and calcium/calmodulin-dependent kinase II (CaMKII, this review challenges this dualistic view and advocates the nature and dignity of each of these key mediators of cardiac remodeling as a multilayered, highly context-sensitive and sophisticated continuum that can be markedly swayed and influenced by a multitude of environmental factors and crosstalk mechanisms.Furthermore this review delineates the importance and essential contributions of degradation and proteolysis to cardiac plasticity and homeostasis and finally aims to integrate the various aspects of protein synthesis and turnover into a comprehensive picture.

  1. Remodeling of intrinsic cardiac neurons: effects of β-adrenergic receptor blockade in guinea pig models of chronic heart disease.

    Science.gov (United States)

    Hardwick, Jean C; Southerland, E Marie; Girasole, Allison E; Ryan, Shannon E; Negrotto, Sara; Ardell, Jeffrey L

    2012-11-01

    Chronic heart disease induces remodeling of cardiac tissue and associated neuronal components. Treatment of chronic heart disease often involves pharmacological blockade of adrenergic receptors. This study examined the specific changes in neuronal sensitivity of guinea pig intrinsic cardiac neurons to autonomic modulators in animals with chronic cardiac disease, in the presence or absence of adrenergic blockage. Myocardial infarction (MI) was produced by ligature of the coronary artery and associated vein on the dorsal surface of the heart. Pressure overload (PO) was induced by a banding of the descending dorsal aorta (∼20% constriction). Animals were allowed to recover for 2 wk and then implanted with an osmotic pump (Alzet) containing either timolol (2 mg·kg(-1)·day(-1)) or vehicle, for a total of 6-7 wk of drug treatment. At termination, intracellular recordings from individual neurons in whole mounts of the cardiac plexus were used to assess changes in physiological responses. Timolol treatment did not inhibit the increased sensitivity to norepinephrine seen in both MI and PO animals, but it did inhibit the stimulatory effects of angiotensin II on the norepinephrine-induced increases in neuronal excitability. Timolol treatment also inhibited the increase in synaptically evoked action potentials observed in PO animals with stimulation of fiber tract bundles. These results demonstrate that β-adrenergic blockade can inhibit specific aspects of remodeling within the intrinsic cardiac plexus. In addition, this effect was preferentially observed with active cardiac disease states, indicating that the β-receptors were more influential on remodeling during dynamic disease progression.

  2. Features of remodeling of right heart chambers according to tissue Doppler and its correlation with cardiac rhythm disturbance in patients with COPD 2-3 severity

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    O. A. Zhuk

    2014-01-01

    Full Text Available The article presents the study of early sings of dysfunction of right and left chambers of heart in patients with COPD 2 - 3 severity, correlation between structural and electrical remodeling of heart according to the stages of pulmonary hypertension. Standard tissue Doppler echocardiographic parameters and modes were used for the diagnosing. We examined 35 patients with COPD 2 - 3 severity; the control group consisted of 15 patients. The ECG Holter monitoring was made for all patients to identify cardiac rhythm disturbance and correlation with the COPD severity. Standard method of the ECG with modes of tissue Doppler (pulsed wave Tissue Doppler Imaging - PW TDI, color tissue Doppler imaging -TDI, tissue myocardial Doppler - TMD, tissue Tracking - TT, Doppler for evaluation of myocardial strain and myocardial strain rate were made to identify the stage of dysfunction. The results of the study concluded that according to the TDI the dysfunction of right ventricle was more apparent in patients with COPD 3 severity. Pathological arrhythmias were significantly detected in group of patients with COPD 3 severity. In compliance with our observations, the reduce of rapid myocardial strain rates and its inverse proportion with the severity in accordance to the evaluation of longitudinal strain and rate of movement of fibrous ring in tricuspid valve were observed in patients with COPD. Thus the application of the TDI modes for evaluating of early signs of cardiac remodeling in patients with COPD and potential adequate jugulation for preventing chronic cor pulmonale is expedient.

  3. Cell death and serum markers of collagen metabolism during cardiac remodeling in Cavia porcellus experimentally infected with Trypanosoma cruzi.

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    Yagahira E Castro-Sesquen

    Full Text Available We studied cell death by apoptosis and necrosis in cardiac remodeling produced by Trypanosoma cruzi infection. In addition, we evaluated collagen I, III, IV (CI, CIII and CIV deposition in cardiac tissue, and their relationship with serum levels of procollagen type I carboxy-terminal propeptide (PICP and procollagen type III amino-terminal propeptide (PIIINP. Eight infected and two uninfected guinea pigs were necropsied at seven time points up to one year post-infection. Cell death by necrosis and apoptosis was determined by histopathological observation and terminal deoxynucleotidyl transferase dUTP nick end labeling, respectively. Deposition of cardiac collagen types was determined by immunohistochemistry and serum levels of PICP, PIIINP, and anti-T. cruzi IgG1 and IgG2 by ELISA. IgG2 (Th1 response predominated throughout the course of infection; IgG1 (Th2 response was detected during the chronic phase. Cardiac cell death by necrosis predominated over apoptosis during the acute phase; during the chronic phase, both apoptosis and necrosis were observed in cardiac cells. Apoptosis was also observed in lymphocytes, endothelial cells and epicardial adipose tissue, especially in the chronic phase. Cardiac levels of CI, CIII, CIV increased progressively, but the highest levels were seen in the chronic phase and were primarily due to increase in CIII and CIV. High serum levels of PICP and PIIINP were observed throughout the infection, and increased levels of both biomarkers were associated with cardiac fibrosis (p = 0.002 and p = 0.038, respectively. These results confirm the role of apoptosis in cell loss mainly during the chronic phase and the utility of PICP and PIIINP as biomarkers of fibrosis in cardiac remodeling during T. cruzi infection.

  4. Roles of HDAC2 and HDAC8 in Cardiac Remodeling in Renovascular Hypertensive Rats and the Effects of Valproic Acid Sodium.

    Science.gov (United States)

    Li, Rui-Fang; Cao, Shan-Shan; Fang, Wei-Jin; Song, Ying; Luo, Xue-Ting; Wang, Hong-Yun; Wang, Jian-Gang

    2017-01-01

    Recent studies indicate that histone deacetylases (HDACs) activity is associated with the development and progression of cardiac hypertrophy. In this study, we investigated the effects of a HDACs inhibitor, valproic acid sodium (VPA), on cardiac remodeling and the differential expression of HDACs in left ventricles (LVs) of renovascular hypertensive rats. Renovascular hypertension was induced in rats by the two-kidney two-clip (2K2C) method. Cardiac remodeling, heart function and the differential expression of HDACs were examined at different weeks after 2K2C operation. The effects of VPA on cardiac remodeling, the expressions of HDACs, transforming growth factor-beta 1 (TGF-β1) and connective tissue growth factor (CTGF) in LV were investigated. The expressions of atrial natriuretic factor, β-myosin heavy chain, HDAC2 and HDAC8 increased in LV of 2K2C rats at 4, 8, 12 weeks after operation. Cardiac dysfunction, cardiac hypertrophy and fibrosis were markedly attenuated by VPA treatment in 2K2C rats. Further studies revealed that VPA inhibited the expressions of HDAC2, HDAC8, TGF-β1 and CTGF in LV of 2K2C rats. In summary, these data indicate that HDAC2 and HDAC8 play a key role in cardiac remodeling in renovascular hypertensive rats and that VPA attenuates hypertension and cardiac remodeling. The effect of VPA is possibly exerted via decreasing HDAC2, HDAC8, TGF-β1 and CTGF expressions in LV of 2K2C rats.

  5. The role of atrial electrical remodeling in the progression of focal atrial ectopy to persistent atrial fibrillation

    NARCIS (Netherlands)

    Hobbs, WJC; Van Gelder, IC; Fitzpatrick, AP; Crijns, HJGM; Garratt, CJ

    1999-01-01

    Focal Atrial Fibrillation and Electrical Remodeling. Although atrial fibrillation- (AF) induced changes in atrial refractoriness (atrial electrical remodeling) have been demonstrated in a number of different animal models, the clinical significance of this process is unknown. We describe a patient i

  6. Vagal Nerve Stimulation Evoked Heart Rate Changes and Protection from Cardiac Remodeling.

    Science.gov (United States)

    Agarwal, Rahul; Mokelke, Eric; Ruble, Stephen B; Stolen, Craig M

    2016-02-01

    This study investigated whether vagal nerve stimulation (VNS) leads to improvements in ischemic heart failure via heart rate modulation. At 7 ± 1 days post left anterior descending artery (LAD) ligation, 63 rats with myocardial infarctions (MI) were implanted with ECG transmitters and VNS devices (MI + VNS, N = 44) or just ECG transmitters (MI, N = 17). VNS stimulation was active from 14 ± 1 days to 8 ± 1 weeks post MI. The average left ventricular (LV) end diastolic volumes at 8 ± 1 weeks were MI = 672.40 μl and MI + VNS = 519.35 μl, p = 0.03. The average heart weights, normalized to body weight (± std) at 14 ± 1 weeks were MI = 3.2 ± 0.6 g*kg(-1) and MI + VNS = 2.9 ± 0.3 g*kg(-1), p = 0.03. The degree of cardiac remodeling was correlated with the magnitude of acute VNS-evoked heart rate (HR) changes. Further research is required to determine if the acute heart rate response to VNS activation is useful as a heart failure biomarker or as a tool for VNS therapy characterization.

  7. Fermented Wheat Germ Extract (Avemar in the Treatment of Cardiac Remodeling and Metabolic Symptoms in Rats

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    Abishek Iyer

    2011-01-01

    Full Text Available Avemar, a product of industrial fermentation of wheat germ with a standardized content of benzoquinone and plant flavonoids, has been tested as an anti-cancer and immunomodulatory dietary supplement. Proposed mechanisms include anti-oxidant and anti-inflammatory actions. This study has determined whether these actions of Avemar may also be useful in the treatment of cardiovascular diseases. Two experimental rat models of cardiovascular remodeling were used in this project: the deoxycorticosterone acetate (DOCA-salt-induced model of chronic hypertension (study I and a high-carbohydrate/high-fat diet-induced model producing chronic symptoms of the metabolic syndrome and its associated cardiovascular complications (study II. Our results in these rat models of hypertension and diet-induced obesity show that treatment with Avemar improved cardiac function, decreased macrophage infiltration resulting in decreased collagen deposition in the ventricular myocardium, reversed an increased stiffness of the left ventricle in the diseased hearts and attenuated increased plasma malondialdehyde concentrations. In addition to the changes in the heart, Avemar reversed glucose intolerance, normalized systolic blood pressure and decreased visceral fat deposition in rats fed a high-fat/high-carbohydrate diet. In conclusion, the fermented wheat germ extract Avemar has a potential role in attenuating chronic hypertension, diabetes or metabolic syndrome-induced cardiovascular symptoms along with metabolic abnormalities such as glucose tolerance and obesity.

  8. Fermented wheat germ extract (avemar) in the treatment of cardiac remodeling and metabolic symptoms in rats.

    Science.gov (United States)

    Iyer, Abishek; Brown, Lindsay

    2011-01-01

    Avemar, a product of industrial fermentation of wheat germ with a standardized content of benzoquinone and plant flavonoids, has been tested as an anti-cancer and immunomodulatory dietary supplement. Proposed mechanisms include anti-oxidant and anti-inflammatory actions. This study has determined whether these actions of Avemar may also be useful in the treatment of cardiovascular diseases. Two experimental rat models of cardiovascular remodeling were used in this project: the deoxycorticosterone acetate (DOCA)-salt-induced model of chronic hypertension (study I) and a high-carbohydrate/high-fat diet-induced model producing chronic symptoms of the metabolic syndrome and its associated cardiovascular complications (study II). Our results in these rat models of hypertension and diet-induced obesity show that treatment with Avemar improved cardiac function, decreased macrophage infiltration resulting in decreased collagen deposition in the ventricular myocardium, reversed an increased stiffness of the left ventricle in the diseased hearts and attenuated increased plasma malondialdehyde concentrations. In addition to the changes in the heart, Avemar reversed glucose intolerance, normalized systolic blood pressure and decreased visceral fat deposition in rats fed a high-fat/high-carbohydrate diet. In conclusion, the fermented wheat germ extract Avemar has a potential role in attenuating chronic hypertension, diabetes or metabolic syndrome-induced cardiovascular symptoms along with metabolic abnormalities such as glucose tolerance and obesity.

  9. Exogenous nerve growth factor supplementation elevates myocardial immunoreactivity and attenuates cardiac remodeling in pressure-overload rats

    Institute of Scientific and Technical Information of China (English)

    Bing He; and Yuming Li; Fan Ye; Xin Zhou; He Li; Xiaoqing Xun; Xiaoqing Ma; Xudong Liu; Zhihong Wang; Pengxiao Xu

    2012-01-01

    It is postulated that supplementation of exogenous nerve growth factor (NGF) might mediate improvement of the cardiac sympathetic nerve function in heart failure (HF).Local intramuscular injection of NGF near the cardiac sympathetic ganglia could influence the innervation pattern,norepinephrine transporter (NET) gene expression,and improve the cardiac remodeling in experimental HF animals.In this study,we injected NGF into the scalenus medius muscles of Sprague-Dawley rats with abdominal aortic constriction (AC).The nerve innervated pattern,left ventricular morphology,and function following injection in rats with AC were investigated respectively by immunohistochemistry and echocardiography.Levels of mRNA expression of NET,growth associated protein 43 (GAP 43),NGF and its receptors TrkA and p75NTR,and brain natriuretic peptide (BNP) were measured by realtime polymerase chain reaction.The results showed that myocardial NGF mRNA levels were comparable in rats with AC.Short-term supplementation of exogenous NGF raised the myocardial NGF immunoreactivity,but did not cause hyperinnervation and NET mRNA upregulation in the AC rats.Furthermore,myocardial TrkA mRNA was found to be remarkably decreased and p75NTR mRNA was increased.Myocardial TrkA downregulation may play a beneficial effect for avoiding the hyperinnervation,and it is reasonable to postulate that p75NTR can function as an NGF receptor in the absence of TrkA.Interestingly,local NGF administration into the neck muscles near the ganglia could attenuate cardiac remodeling and downregulate BNP mRNA.These results suggest that exogenous NGF can reach the target tissue along the axons anterogradely,and improve the cardiac remodeling.

  10. Effects of Amiodarone plus Losartan on Electrical Remodeling in Rapid Atrial Pacing in Rabbits

    Institute of Scientific and Technical Information of China (English)

    Liye Wei; Yue Xia; Guoqing Qi; Qingwen Zhang

    2008-01-01

    Objectives To investigate the electrical remodeling and the effects of amiodarone and losartan on electrical remode-ling in rapid atrial pacing on rabbit model. Methods 40 normal rabbits were randomly divided into 4 groups: the sa-line group (control group), amiodarone group, losartan group, ami + los group. All rabbits were raised drugs in a week. The atrial effective refractory period (AERP) was measured. Then, take a rapid atrial pacing (600 bpm) and the AERP was measured after 0. 5, 1, 2, 4, 6 and 8 hours pacing and 30 minutes after the termination of rapid pacing. Results ① In control group, after 8 hours rapid pacing, AERP 200 and AERP 150 were significantly shortened 16. 11%± 3. 1% (P <0. 01) and 9. 99%±4. 2% (P <0. 01). And the degree of AERP shortening induced by rapid pacing was greater at basic cycle lengths of 200 ms (BCL200) than that at BCL150. The AERP of amiodarone, losartan group and anti + los group were not shortened during rapid pacing.② In the control group, after the termination of rapid pacing, the AERP gradually increased. The AERP at all of the BCLS examined recovered to almost the 95.78% and 96. 76% of baseline values within the first 10 minutes and recovered to almost the 99. 07% and 99. 39% of baseline values within the first 30 minutes. Condusions Short-term atrial rapid pacing can induce the atrial electrical remodeling. Amiodarone and losartan can prevent the electrical remodeling.

  11. Early recurrences of atrial fibrillation after electrical cardioversion : A result of fibrillation-induced electrical remodeling of the atria?

    NARCIS (Netherlands)

    Tieleman, RG; Van Gelder, IC; Crijns, HJGM; De Kam, PJ; Van den Berg, MP; Haaksma, J; Van der Woude, HJ; Allessie, MA

    1998-01-01

    Objectives, We sought to investigate whether, in humans, the timing and incidence of a relapse of atrial fibrillation (AF) during the first month after cardioversion indicates the presence of electrical remodeling and whether this could be influenced by prevention of intracellular calcium overload d

  12. Effect of Different Styles of Coronary Heart Disease and Its Risk Factors on Cardiac Remodeling and Dysfunction

    Institute of Scientific and Technical Information of China (English)

    Wang Xuelihong; Guo Xuewei; Ma Yushan; Su Shuangshan; Guo Xiangyu

    2006-01-01

    Objectives To evaluate the effect of different styles of coronary heart disease (CHD),different regions of acute myocardial infarction (AMI),its risk factors and branches of coronary stenosis on left ventricular remodeling and dysfunction by applying echocardiography. Methods 251 patients with CHD and 96 patients without CHD (NoCHD) were verified by selective coronary angiography. CHD patients were divided into stable angina pectoris(SAP) 26, unstable angina pectoris(UAP) 53, acute myocardial infarction (AMI) 140 and old myocardial infarction (OMI) 30 based on clinical situation, cTnT, cardiac enzyme and ECG. AMI patients were further divided into subgroups including acute anterior myocardial infarct (Aa,n =53), acute inferior myocardial infarction(Ai, n=54)and Aa+Ai(n=33) based on ECG. Cardiac parameters:end-diastolic interventricular septum thickness (IVSd),end-diastolic left ventricular internal diameter(LVd ),left ventricular mass (LM), end-diastolic left ventricular volume (EDV), end-systolic left ventricular volume (ESV) and left ventricular ejection fraction(LVEF) were measured by ACUSON 128XP/10 echocardiography.Multiples linear regression analyses were performed to test statistical associations between LVEF and the involved branches of coronary stenosis, blood pressure, lipids, glucose and etc after onset of myocardial infarction. Results EDV and ESV were increased and LVEF decreased on patients with AMI,OMI and UAP (P<0.05-0.0001). LM was mainly increased in patients with OMI (P<0.01) and LVd was mainly enlarged in patients with AMI. EF was significantly decreased and EDV, ESV, LM and LVd were remarkably increased in AMI patients with Aa and Aa+Ai. With the multiple linear regression analyses by SPSS software, we found that LVEF was negatively correlated to the involved branches of coronary stenosis as well as to systolic blood pressure after onset of myocardial infarction while there was no significant correlation between LVEF and other factors. LVEF

  13. The Cause and Mechanism of Cardiac Electrical Instability. Defibrillation Mechanism

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    Rustam G. Habchabov

    2012-06-01

    Full Text Available The reason for the ominous arrhythmias pathway, causing sudden somatic death from cardiovascular diseases is still not clear, cardiological examinations of this phenomenon are conducted throughout the world. Laceration of connective insulating tissue membrane of heart pathway with ectopic nodes oxidation may cause ominous arrhythmias; nobody has considered this cause as a cardiac electrical instability before. Defibrillator electric discharges cannot penetrate into myocardium due to the connective insulating tissue membrane, nobody has considered nervous system, transmitting electricity.

  14. Effects of spironolactone on electrical and structural remodeling of atrium in congestive heart failure dogs

    Institute of Scientific and Technical Information of China (English)

    YANG Shu-sen; XIU Chun-hong; LI Wei-min; HAN Wei; ZHOU Hong-yan; DONG Guo; WANG Bai-chun; HUO Hong; WEI Na; CAO Yong; ZHOU Guo

    2008-01-01

    Background Renin-angiotensin-aldosterone System has been demonstrated to be associated with both congestive heart failure (CHF) and atrial fibrillation (AF). This study investigated the effects of spironolactone, a kind of aldosterone antagonist, on atrial electrical remodeling and fibrosis in CHF dogs induced by chronic rapid ventricular pacing. Methods Twenty one dogs were randomly divided into sham-operated group, control group, and spironolactone group. In control group and spironolactone group, dogs were ventricular paced at 220 beats per minute for 6 weeks. Additionally, spironolactone at 15 mg·kg-1·d-1 was given to dogs 1 week before rapid ventricular pacing until pacing stopped. Transthoracic and transoesophageal echocardiographic examinations were performed to detect structural and functional changes of the atrium. Swan2 Ganz floating catheters were used to measure hemadynamics variances. Atrial effective refractory period (AERP), AERP dispersion (AERPd), intra- and inter-atrium conduction time (CT) and intra-atrium conduction velocity (CV) were determined. The inducibility and duration of AF were also measured in all groups. Finally, atrial fibrosis was quantified with Massen staining.Results AERP did not change significantly after dogs were ventricular paced for 6 weeks. However, AERPd, intra- and inter-atrium CT increased significantly, and CV decreased apparently, which was negatively correlated to the atrial fibrosis (r=-0.74, P<0.05). Simultaneously, left atriums were enlarged and cardiac hemadynamics worsened in pacing dogs. Although spironolactone could not affect cardiac hemadynamics effectively, it can obviously improve left atrial ejection fraction (P<0.05). Spironolactone treatment did not alter AERP duration, but this medicine dramatically decreased AERPd (P<0.05), shortened intra- and inter-atrium conduction time (P<0.05), and increased atrium CV. Moreover, spironolactone decreased the inducibility and duration of AF (P<0.05),as

  15. Postnatal ablation of Foxm1 from cardiomyocytes causes late onset cardiac hypertrophy and fibrosis without exacerbating pressure overload-induced cardiac remodeling.

    Science.gov (United States)

    Bolte, Craig; Zhang, Yufang; York, Allen; Kalin, Tanya V; Schultz, Jo El J; Molkentin, Jeffery D; Kalinichenko, Vladimir V

    2012-01-01

    Heart disease remains a leading cause of morbidity and mortality in the industrialized world. Hypertrophic cardiomyopathy is the most common genetic cardiovascular disorder and the most common cause of sudden cardiac death. Foxm1 transcription factor (also known as HFH-11B, Trident, Win or MPP2) plays an important role in the pathogenesis of various cancers and is a critical mediator of post-injury repair in multiple organs. Foxm1 has been previously shown to be essential for heart development and proliferation of embryonic cardiomyocytes. However, the role of Foxm1 in postnatal heart development and in cardiac injury has not been evaluated. To delete Foxm1 in postnatal cardiomyocytes, αMHC-Cre/Foxm1(fl/fl) mice were generated. Surprisingly, αMHC-Cre/Foxm1(fl/fl) mice exhibited normal cardiomyocyte proliferation at postnatal day seven and had no defects in cardiac structure or function but developed cardiac hypertrophy and fibrosis late in life. The development of cardiomyocyte hypertrophy and cardiac fibrosis in aged Foxm1-deficient mice was associated with reduced expression of Hey2, an important regulator of cardiac homeostasis, and increased expression of genes critical for cardiac remodeling, including MMP9, αSMA, fibronectin and vimentin. We also found that following aortic constriction Foxm1 mRNA and protein were induced in cardiomyocytes. However, Foxm1 deletion did not exacerbate cardiac hypertrophy or fibrosis following chronic pressure overload. Our results demonstrate that Foxm1 regulates genes critical for age-induced cardiomyocyte hypertrophy and cardiac fibrosis.

  16. Sustained cardiac remodeling after a short-term very low calorie diet in type 2 diabetes mellitus patients.

    Science.gov (United States)

    Jonker, Jacqueline T; Snel, Marieke; Hammer, Sebastiaan; Jazet, Ingrid M; van der Meer, Rutger W; Pijl, Hanno; Meinders, A Edo; de Roos, Albert; Smit, Johannes W A; Romijn, Johannes A; Lamb, Hildo J

    2014-01-01

    A very low calorie diet (VLCD) results in cardiac remodeling and improved diastolic function. It is unknown how long these effects sustain after reintroduction of a regular diet. We aimed to assess the long-term effects of initial weight loss by VLCD on cardiac dimensions and function in type 2 diabetes mellitus (T2DM) patients. Fourteen insulin-dependent T2DM patients (mean ± SEM: age 53 ± 2 years; BMI 35 ± 1 kg/m(2)) were treated by a VLCD (450 kcal/day) during 16 weeks. Cardiac function and myocardial triglyceride (TG) content were measured by magnetic resonance imaging and spectroscopy at baseline, after a 16-week VLCD and after 14 months of follow-up on a regular diet. BMI decreased from 35 ± 1 to 28 ± 1 kg/m(2) after VLCD and increased again to 32 ± 1 kg/m(2) at 18 months (both P diet.

  17. Low Intensity Physical Exercise Attenuates Cardiac Remodeling and Myocardial Oxidative Stress and Dysfunction in Diabetic Rats

    Directory of Open Access Journals (Sweden)

    C. Gimenes

    2015-01-01

    Full Text Available We evaluated the effects of a low intensity aerobic exercise protocol on cardiac remodeling and myocardial function in diabetic rats. Wistar rats were assigned into four groups: sedentary control (C-Sed, exercised control (C-Ex, sedentary diabetes (DM-Sed, and exercised diabetes (DM-Ex. Diabetes was induced by intraperitoneal injection of streptozotocin. Rats exercised for 9 weeks in treadmill at 11 m/min, 18 min/day. Myocardial function was evaluated in left ventricular (LV papillary muscles and oxidative stress in LV tissue. Statistical analysis was given by ANOVA or Kruskal-Wallis. Echocardiogram showed diabetic groups with higher LV diastolic diameter-to-body weight ratio and lower posterior wall shortening velocity than controls. Left atrium diameter was lower in DM-Ex than DM-Sed (C-Sed: 5.73±0.49; C-Ex: 5.67±0.53; DM-Sed: 6.41±0.54; DM-Ex: 5.81±0.50 mm; P<0.05 DM-Sed vs C-Sed and DM-Ex. Papillary muscle function was depressed in DM-Sed compared to C-Sed. Exercise attenuated this change in DM-Ex. Lipid hydroperoxide concentration was higher in DM-Sed than C-Sed and DM-Ex. Catalase and superoxide dismutase activities were lower in diabetics than controls and higher in DM-Ex than DM-Sed. Glutathione peroxidase activity was lower in DM-Sed than C-Sed and DM-Ex. Conclusion. Low intensity exercise attenuates left atrium dilation and myocardial oxidative stress and dysfunction in type 1 diabetic rats.

  18. Endothelial cells overexpressing IL-8 receptor reduce cardiac remodeling and dysfunction following myocardial infarction.

    Science.gov (United States)

    Zhao, Xiangmin; Zhang, Wei; Xing, Dongqi; Li, Peng; Fu, Jinyan; Gong, Kaizheng; Hage, Fadi G; Oparil, Suzanne; Chen, Yiu-Fai

    2013-08-15

    The endothelium is a dynamic component of the cardiovascular system that plays an important role in health and disease. This study tested the hypothesis that targeted delivery of endothelial cells (ECs) overexpressing neutrophil membrane IL-8 receptors IL8RA and IL8RB reduces acute myocardial infarction (MI)-induced left ventricular (LV) remodeling and dysfunction and increases neovascularization in the area at risk surrounding the infarcted tissue. MI was created by ligating the left anterior descending coronary artery in 12-wk-old male Sprague-Dawley rats. Four groups of rats were studied: group 1: sham-operated rats without MI or EC transfusion; group 2: MI rats with intravenous vehicle; group 3: MI rats with transfused ECs transduced with empty adenoviral vector (Null-EC); and group 4: MI rats with transfused ECs overexpressing IL8RA/RB (1.5 × 10⁶ cells post-MI). Two weeks after MI, LV function was assessed by echocardiography; infarct size was assessed by triphenyltetrazolium chloride (live tissue) and picrosirus red (collagen) staining, and capillary density and neutrophil infiltration in the area at risk were measured by CD31 and MPO immunohistochemical staining, respectively. When compared with the MI + vehicle and MI-Null-EC groups, transfusion of IL8RA/RB-ECs decreased neutrophil infiltration and pro-inflammatory cytokine expression and increased capillary density in the area at risk, decreased infarct size, and reduced MI-induced LV dysfunction. These findings provide proof of principle that targeted delivery of ECs is effective in repairing injured cardiac tissue. Targeted delivery of ECs to infarcted hearts provides a potential novel strategy for the treatment of acute MI in humans.

  19. Developmental remodeling and shortening of the cardiac outflow tract involves myocyte programmed cell death.

    Science.gov (United States)

    Watanabe, M; Choudhry, A; Berlan, M; Singal, A; Siwik, E; Mohr, S; Fisher, S A

    1998-10-01

    The embryonic outflow tract is a simple tubular structure that connects the single primitive ventricle with the aortic sac and aortic arch arteries. This structure undergoes a complex sequence of morphogenetic processes to become the portion of the heart that aligns the right and left ventricles with the pulmonary artery and aorta. Abnormalities of the outflow tract are involved in many clinically significant congenital cardiac defects; however, the cellular and molecular processes governing the development of this important structure are incompletely understood. Histologic and tissue-tagging studies indicate that the outflow tract tissues compact and are incorporated predominantly into a region of the right ventricle. The hypothesis tested in the current study was that cell death or apoptosis in the muscular portion of the outflow tract is an important cellular mechanism for outflow tract shortening. The tubular outflow tract myocardium was specifically marked by infecting myocytes of the chicken embryo heart with a recombinant replication-defective adenovirus expressing beta-galactosidase (beta-gal) under the control of the cytomegalovirus promoter. Histochemical detection of the beta -gal-labeled outflow tract myocytes revealed that the tubular structure shortened to become a compact ring at the level of the pulmonic infundibulum over several days of development (stages 25-32, embryonic days 4-8). The appearance of apoptotic cardiomyocytes was correlated with OFT shortening by two histologic assays, TUNEL labeling of DNA fragments and AnnexinV binding. The rise and fall in the number of apoptotic myocytes detected by histologic analyses paralleled the change in activity levels of Caspase-3, a protease in the apoptotic cascade, measured in outflow tract homogenates. These results suggest that the elimination of myocytes by programmed cell death is one mechanism by which the outflow tract myocardium remodels to form the proper connection between the ventricular

  20. Design of electrical stimulation bioreactors for cardiac tissue engineering.

    Science.gov (United States)

    Tandon, N; Marsano, A; Cannizzaro, C; Voldman, J; Vunjak-Novakovic, G

    2008-01-01

    Electrical stimulation has been shown to improve functional assembly of cardiomyocytes in vitro for cardiac tissue engineering. Carbon electrodes were found in past studies to have the best current injection characteristics. The goal of this study was to develop rational experimental design principles for the electrodes and stimulation regime, in particular electrode configuration, electrode ageing, and stimulation amplitude. Carbon rod electrodes were compared via electrochemical impedance spectroscopy (EIS) and we identified a safety range of 0 to 8 V/cm by comparing excitation thresholds and maximum capture rates for neonatal rat cardiomyocytes cultured with electrical stimulation. We conclude with recommendations for studies involving carbon electrodes for cardiac tissue engineering.

  1. External cardiac compression may be harmful in some scenarios of pulseless electrical activity.

    LENUS (Irish Health Repository)

    Hogan, T S

    2012-10-01

    Pulseless electrical activity occurs when organised or semi-organised electrical activity of the heart persists but the product of systemic vascular resistance and the increase in systemic arterial flow generated by the ejection of the left venticular stroke volume is not sufficient to produce a clinically detectable pulse. Pulseless electrical activity encompasses a very heterogeneous variety of severe circulatory shock states ranging in severity from pseudo-cardiac arrest to effective cardiac arrest. Outcomes of cardiopulmonary resuscitation for pulseless electrical activity are generally poor. Impairment of cardiac filling is the limiting factor to cardiac output in many scenarios of pulseless electrical activity, including extreme vasodilatory shock states. There is no evidence that external cardiac compression can increase cardiac output when impaired cardiac filling is the limiting factor to cardiac output. If impaired cardiac filling is the limiting factor to cardiac output and the heart is effectively ejecting all the blood returning to it, then external cardiac compression can only increase cardiac output if it increases venous return and cardiac filling. Repeated cardiac compression asynchronous with the patient\\'s cardiac cycle and raised mean intrathoracic pressure due to chest compression can be expected to reduce rather than to increase cardiac filling and therefore to reduce rather than to increase cardiac output in such circumstances. The hypothesis is proposed that the performance of external cardiac compression will have zero or negative effect on cardiac output in pulseless electrical activity when impaired cardiac filling is the limiting factor to cardiac output. External cardiac compression may be both directly and indirectly harmful to significant sub-groups of patients with pulseless electrical activity. We have neither evidence nor theory to provide comfort that external cardiac compression is not harmful in many scenarios of pulseless

  2. External cardiac compression may be harmful in some scenarios of pulseless electrical activity.

    Science.gov (United States)

    Hogan, T S

    2012-10-01

    Pulseless electrical activity occurs when organised or semi-organised electrical activity of the heart persists but the product of systemic vascular resistance and the increase in systemic arterial flow generated by the ejection of the left venticular stroke volume is not sufficient to produce a clinically detectable pulse. Pulseless electrical activity encompasses a very heterogeneous variety of severe circulatory shock states ranging in severity from pseudo-cardiac arrest to effective cardiac arrest. Outcomes of cardiopulmonary resuscitation for pulseless electrical activity are generally poor. Impairment of cardiac filling is the limiting factor to cardiac output in many scenarios of pulseless electrical activity, including extreme vasodilatory shock states. There is no evidence that external cardiac compression can increase cardiac output when impaired cardiac filling is the limiting factor to cardiac output. If impaired cardiac filling is the limiting factor to cardiac output and the heart is effectively ejecting all the blood returning to it, then external cardiac compression can only increase cardiac output if it increases venous return and cardiac filling. Repeated cardiac compression asynchronous with the patient's cardiac cycle and raised mean intrathoracic pressure due to chest compression can be expected to reduce rather than to increase cardiac filling and therefore to reduce rather than to increase cardiac output in such circumstances. The hypothesis is proposed that the performance of external cardiac compression will have zero or negative effect on cardiac output in pulseless electrical activity when impaired cardiac filling is the limiting factor to cardiac output. External cardiac compression may be both directly and indirectly harmful to significant sub-groups of patients with pulseless electrical activity. We have neither evidence nor theory to provide comfort that external cardiac compression is not harmful in many scenarios of pulseless

  3. Interleukin-2/Anti-Interleukin-2 Immune Complex Attenuates Cardiac Remodeling after Myocardial Infarction through Expansion of Regulatory T Cells

    Directory of Open Access Journals (Sweden)

    Zhipeng Zeng

    2016-01-01

    Full Text Available CD4+CD25+Foxp3+ regulatory T cells (Treg cells have protective effects in wound healing and adverse ventricular remodeling after myocardial infarction (MI. We hypothesize that the interleukin- (IL- 2 complex comprising the recombinant mouse IL-2/anti-IL-2 mAb (JES6-1 attenuates cardiac remodeling after MI through the expansion of Treg. Mice were subjected to surgical left anterior descending coronary artery ligation and treated with either PBS or IL-2 complex. The IL-2 complex significantly attenuates ventricular remodeling, as demonstrated by reduced infarct size, improved left ventricular (LV function, and attenuated cardiomyocyte apoptosis. The IL-2 complex increased the percentage of CD4+CD25+Foxp3+ Treg cells, which may be recruited to the infarcted heart, and decreased the frequencies of IFN-γ- and IL-17-producing CD4+ T helper (Th cells among the CD4+Foxp3− T cells in the spleen. Furthermore, the IL-2 complex inhibited the gene expression of proinflammatory cytokines as well as macrophage infiltrates in the infarcted myocardium and induced the differentiation of macrophages from M1 to M2 phenotype in border zone of infarcted myocardium. Our studies indicate that the IL-2 complex may serve as a promising therapeutic approach to attenuate adverse remodeling after MI through expanding Treg cells specifically.

  4. Intramyocardial Delivery of Mesenchymal Stem Cell-Seeded Hydrogel Preserves Cardiac Function and Attenuates Ventricular Remodeling after Myocardial Infarction

    Science.gov (United States)

    Mathieu, Eva; Lamirault, Guillaume; Toquet, Claire; Lhommet, Pierre; Rederstorff, Emilie; Sourice, Sophie; Biteau, Kevin; Hulin, Philippe; Forest, Virginie; Weiss, Pierre

    2012-01-01

    Background To improve the efficacy of bone marrow-derived mesenchymal stem cell (MSC) therapy targeted to infarcted myocardium, we investigated whether a self-setting silanized hydroxypropyl methylcellulose (Si-HPMC) hydrogel seeded with MSC (MSC+hydrogel) could preserve cardiac function and attenuate left ventricular (LV) remodeling during an 8-week follow-up study in a rat model of myocardial infarction (MI). Methodology/Principal Finding Si-HPMC hydrogel alone, MSC alone or MSC+hydrogel were injected into the myocardium immediately after coronary artery ligation in female Lewis rats. Animals in the MSC+hydrogel group showed an increase in cardiac function up to 28 days after MI and a mid-term prevention of cardiac function alteration at day 56. Histological analyses indicated that the injection of MSC+hydrogel induced a decrease in MI size and an increase in scar thickness and ultimately limited the transmural extent of MI. These findings show that intramyocardial injection of MSC+hydrogel induced short-term recovery of ventricular function and mid-term attenuation of remodeling after MI. Conclusion/Significance These beneficial effects may be related to the specific scaffolding properties of the Si-HPMC hydrogel that may provide the ability to support MSC injection and engraftment within myocardium. PMID:23284842

  5. Intramyocardial delivery of mesenchymal stem cell-seeded hydrogel preserves cardiac function and attenuates ventricular remodeling after myocardial infarction.

    Directory of Open Access Journals (Sweden)

    Eva Mathieu

    Full Text Available BACKGROUND: To improve the efficacy of bone marrow-derived mesenchymal stem cell (MSC therapy targeted to infarcted myocardium, we investigated whether a self-setting silanized hydroxypropyl methylcellulose (Si-HPMC hydrogel seeded with MSC (MSC+hydrogel could preserve cardiac function and attenuate left ventricular (LV remodeling during an 8-week follow-up study in a rat model of myocardial infarction (MI. METHODOLOGY/PRINCIPAL FINDING: Si-HPMC hydrogel alone, MSC alone or MSC+hydrogel were injected into the myocardium immediately after coronary artery ligation in female Lewis rats. Animals in the MSC+hydrogel group showed an increase in cardiac function up to 28 days after MI and a mid-term prevention of cardiac function alteration at day 56. Histological analyses indicated that the injection of MSC+hydrogel induced a decrease in MI size and an increase in scar thickness and ultimately limited the transmural extent of MI. These findings show that intramyocardial injection of MSC+hydrogel induced short-term recovery of ventricular function and mid-term attenuation of remodeling after MI. CONCLUSION/SIGNIFICANCE: These beneficial effects may be related to the specific scaffolding properties of the Si-HPMC hydrogel that may provide the ability to support MSC injection and engraftment within myocardium.

  6. Impact of leucine supplementation on exercise training induced anti-cardiac remodeling effect in heart failure mice.

    Science.gov (United States)

    de Moraes, Wilson Max Almeida Monteiro; Melara, Thaís Plasti; de Souza, Pamella Ramona Moraes; Guimarães, Fabiana de Salvi; Bozi, Luiz Henrique Marchesi; Brum, Patricia Chakur; Medeiros, Alessandra

    2015-05-15

    Leucine supplementation potentiates the effects of aerobic exercise training (AET) on skeletal muscle; however, its potential effects associated with AET on cardiac muscle have not been clarified yet. We tested whether leucine supplementation would potentiate the anti-cardiac remodeling effect of AET in a genetic model of sympathetic hyperactivity-induced heart failure in mice (α2A/α2CARKO). Mice were assigned to five groups: wild type mice treated with placebo and sedentary (WT, n = 11), α2A/α2CARKO treated with placebo and sedentary (KO, n = 9), α2A/α2CARKO treated with leucine and sedentary (KOL, n = 11), α2A/α2CARKO treated with placebo and AET (KOT, n = 12) or α2A/α2CARKO treated with leucine and AET (KOLT, n = 12). AET consisted of four weeks on a treadmill with 60 min sessions (six days/week, 60% of maximal speed) and administration by gavage of leucine (1.35 g/kg/day) or placebo (distilled water). The AET significantly improved exercise capacity, fractional shortening and re-established cardiomyocytes' diameter and collagen fraction in KOT. Additionally, AET significantly prevented the proteasome hyperactivity, increased misfolded proteins and HSP27 expression. Isolated leucine supplementation displayed no effect on cardiac function and structure (KOL), however, when associated with AET (KOLT), it increased exercise tolerance to a higher degree than isolated AET (KOT) despite no additional effects on AET induced anti-cardiac remodeling. Our results provide evidence for the modest impact of leucine supplementation on cardiac structure and function in exercised heart failure mice. Leucine supplementation potentiated AET effects on exercise tolerance, which might be related to its recognized impact on skeletal muscle.

  7. Salvianolic acid B functioned as a competitive inhibitor of matrix metalloproteinase-9 and efficiently prevented cardiac remodeling

    Science.gov (United States)

    2010-01-01

    Background Infarct-induced left ventricular (LV) remodeling is a deleterious consequence after acute myocardial infarction (MI) which may further advance to congestive heart failure. Therefore, new therapeutic strategies to attenuate the effects of LV remodeling are urgently needed. Salvianolic acid B (SalB) from Salviae mitiorrhizae, which has been widely used in China for the treatment of cardiovascular diseases, is a potential candidate for therapeutic intervention of LV remodeling targeting matrix metalloproteinase-9 (MMP-9). Results Molecular modeling and LIGPLOT analysis revealed in silico docking of SalB at the catalytic site of MMP-9. Following this lead, we expressed truncated MMP-9 which contains only the catalytic domain, and used this active protein for in-gel gelatin zymography, enzymatic analysis, and SalB binding by Biacore. Data generated from these assays indicated that SalB functioned as a competitive inhibitor of MMP-9. In our rat model for cardiac remodeling, western blot, echocardiography, hemodynamic measurement and histopathological detection were used to detect the effects and mechanism of SalB on cardio-protection. Our results showed that in MI rat, SalB selectively inhibited MMP-9 activities without affecting MMP-9 expression while no effect of SalB was seen on MMP-2. Moreover, SalB treatment in MI rat could efficiently increase left ventricle wall thickness, improve heart contractility, and decrease heart fibrosis. Conclusions As a competitive inhibitor of MMP-9, SalB presents significant effects on preventing LV structural damage and preserving cardiac function. Further studies to develop SalB and its analogues for their potential for cardioprotection in clinic are warranted. PMID:20735854

  8. Characterization of electrical stimulation electrodes for cardiac tissue engineering.

    Science.gov (United States)

    Tandon, Nina; Cannizzaro, Chris; Figallo, Elisa; Voldman, Joel; Vunjak-Novakovic, Gordana

    2006-01-01

    Electrical stimulation has been shown to improve functional assembly of cardiomyocytes in vitro for cardiac tissue engineering. The goal of this study was to assess the conditions of electrical stimulation with respect to the electrode geometry, material properties and charge-transfer characteristics at the electrode-electrolyte interface. We compared various biocompatible materials, including nanoporous carbon, stainless steel, titanium and titanium nitride, for use in cardiac tissue engineering bioreactors. The faradaic and non-faradaic charge transfer mechanisms were assessed by electrochemical impedance spectroscopy (EIS), studying current injection characteristics, and examining surface properties of electrodes with scanning electron microscopy. Carbon electrodes were found to have the best current injection characteristics. However, these electrodes require careful handling because of their limited mechanical strength. The efficacy of various electrodes for use in 2-D and 3-D cardiac tissue engineering systems with neonatal rat cardiomyocytes is being determined by assessing cell viability, amplitude of contractions, excitation thresholds, maximum capture rate, and tissue morphology.

  9. Electro-Anatomical Characterization by Cardiac Electric Near-Fields

    Science.gov (United States)

    2007-11-02

    CHARACTERIZATION BY CARDIAC ELECTRIC NEAR-FIELDS E. Hofer1, G. Plank2, I. Schafferhofer1, D. Sanchez-Quintana3 1Institute of Medical Physics and...Project Number Task Number Work Unit Number Performing Organization Name(s) and Address(es) Institute of Medical Physics and Biophysics Karl-Frazens

  10. Anti-inflammatory, Antithrombotic and Cardiac Remodeling Preventive Effects of Eugenol in Isoproterenol-Induced Myocardial Infarction in Wistar Rat.

    Science.gov (United States)

    Mnafgui, Kais; Hajji, Raouf; Derbali, Fatma; Gammoudi, Anis; Khabbabi, Gaddour; Ellefi, Hedi; Allouche, Noureddine; Kadri, Adel; Gharsallah, Neji

    2016-10-01

    This study aimed to evaluate the antithrombotic, anti-inflammatory and anti-cardiac remodeling properties of eugenol in isoproterenol-induced myocardial infarction in rats. Male Wistar rats were randomly divided into four groups, control, iso [100 mg/kg body weight was injected subcutaneously into rats at an interval of 24 h for 2 days (6th and 7th day) to induce MI] and pretreated animals with clopidogrel (0.2 mg/kg) and eugenol (50 mg/kg) orally for 7 days and intoxicated with isoproterenol (Iso + Clop) and (Iso + EG) groups. Isoproterenol-induced myocardial infarcted rats showed notable changes in the ECG pattern, increase in heart weight index, deterioration in the hemodynamic function and rise in plasma level of troponin-T, CK-MB and LDH and ALT by 316, 74, 172 and 45 %, respectively, with histological myocardium necrosis and cells inflammatory infiltration. In addition, significant increases in plasma levels of inflammatory biomarkers such as fibrinogen, α1, α2, β1, β2 and γ globulins with decrease level of albumin were observed in infarcted rats as compared to normal ones. Else, the angiotensin-converting enzyme (ACE) activity in plasma, kidney and heart of the isoproterenol-induced rats was significantly increased by 34, 47 and 93 %, respectively, as compared to normal group. However, the administration of eugenol induced a clear improvement in cardiac biomarkers injury, reduced inflammatory mediators proteins, increased heart activities of superoxide dismutase and glutathione peroxidase with reduce in thiobarbituric acid-reactive substances content and inhibition of ventricular remodeling process through inhibition of ACE activity. Overall, eugenol evidences high preventive effects from cardiac remodeling process.

  11. Novel Sulfur Metabolites of Garlic Attenuate Cardiac Hypertrophy and Remodeling through Induction of Na+/K+-ATPase Expression

    Science.gov (United States)

    Khatua, Tarak N.; Borkar, Roshan M.; Mohammed, Soheb A.; Dinda, Amit K.; Srinivas, R.; Banerjee, Sanjay K.

    2017-01-01

    Epidemiologic studies show an inverse correlation between garlic consumption and progression of cardiovascular disease. However, the molecular basis for the beneficial effect of garlic on the heart is not known. Therefore, the objective of the present study was to (1) investigate the effect of raw garlic on isoproterenol (Iso) induced cardiac hypertrophy (2) find the active metabolites of garlic responsible for the beneficial effect. Cardiac hypertrophy was induced in rats by subcutaneous single injection of Iso 5 mg kg-1 day-1 for 15 days and the effect of garlic (250 mg/kg/day orally) was evaluated. Garlic metabolites in in vivo were identified by LC/MS study. The effect of garlic and its metabolites were evaluated against hypertrophy in H9C2 cells. Garlic normalized cardiac oxidative stress after Iso administration. Cardiac pathology and mitochondrial enzyme activities were improved in hypertrophy heart after garlic administration. Decreased Na+/K+-ATPase protein level that observed in hypertrophy heart was increased after garlic administration. We identified three garlic metabolites in rat serum. To confirm the role of garlic metabolites on cardiac hypertrophy, Na+/K+-ATPase expression and intracellular calcium levels were measured after treating H9C2 cells with raw garlic and two of its active metabolites, allyl methyl sulfide and allyl methyl sulfoxide. Raw garlic and both metabolites increased Na+/K+-ATPase protein level and decreased intracellular calcium levels and cell size in Iso treated H9C2 cells. This antihypertrophic effect of garlic and its sulfur metabolites were lost in H9C2 cells in presence of Na+/K+-ATPase inhibitor. In conclusion, garlic and its active metabolites increased Na+/K+-ATPase in rat heart, and attenuated cardiac hypertrophy and associated remodeling. Our data suggest that identified new garlic metabolites may be useful for therapeutic intervention against cardiac hypertrophy. PMID:28194108

  12. Role of thyroid hormones in ventricular remodeling.

    Science.gov (United States)

    Rajagopalan, Viswanathan; Gerdes, A Martin

    2015-04-01

    Cardiac remodeling includes alterations in molecular, cellular, and interstitial systems contributing to changes in size, shape, and function of the heart. This may be the result of injury, alterations in hemodynamic load, neurohormonal effects, electrical abnormalities, metabolic changes, etc. Thyroid hormones (THs) serve as master regulators for diverse remodeling processes of the cardiovascular system-from the prenatal period to death. THs promote a beneficial cardiomyocyte shape and improve contractility, relaxation, and survival via reversal of molecular remodeling. THs reduce fibrosis by decreasing interstitial collagen and reduce the incidence and duration of arrhythmias via remodeling ion channel expression and function. THs restore metabolic function and also improve blood flow both by direct effects on the vessel architecture and decreasing atherosclerosis. Optimal levels of THs both in the circulation and in cardiac tissues are critical for normal homeostasis. This review highlights TH-based remodeling and clinically translatable strategies for diverse cardiovascular disorders.

  13. Cardiac Myocyte De Novo DNA Methyltransferases 3a/3b Are Dispensable for Cardiac Function and Remodeling after Chronic Pressure Overload in Mice.

    Directory of Open Access Journals (Sweden)

    Thomas G Nührenberg

    Full Text Available Recent studies reported altered DNA methylation in failing human hearts. This may suggest a role for de novo DNA methylation in the development of heart failure. Here, we tested whether cardiomyocyte-specific loss of de novo DNA methyltransferases Dnmt3a and Dnmt3b altered cardiac function and remodeling after chronic left ventricular pressure overload.Mice with specific ablation of Dnmt3a and Dnmt3b expression in cardiomyocytes were generated by crossing floxed Dnmt3afl and Dnmt3bfl alleles with mice expressing Cre recombinase under control of the atrial myosin light chain gene promoter. The efficacy of combined Dnmt3a/3b ablation (DKO was characterized on cardiomyocyte-specific genomic DNA and mRNA levels. Cardiac phenotyping was carried out without (sham or with left ventricular pressure overload induced by transverse aortic constriction (TAC. Under similar conditions, cardiac genome-wide transcriptional profiling was performed and DNA methylation levels of promoters of differentially regulated genes were assessed by pyrosequencing.DKO cardiomyocytes showed virtual absence of targeted Dnmt3a and Dnmt3b mRNA transcripts. Cardiac phenotyping revealed no significant differences between DKO and control mice under sham and TAC conditions. Transcriptome analyses identified upregulation of 44 and downregulation of 9 genes in DKO as compared with control sham mice. TAC mice showed similar changes with substantial overlap of regulated genes compared to sham. Promoters of upregulated genes were largely unmethylated in DKO compared to control mice.The absence of cardiac pathology in the presence of the predicted molecular phenotype suggests that de novo DNA methylation in cardiomyocytes is dispensable for adaptive mechanisms after chronic cardiac pressure overload.

  14. Alterations in the interleukin-1/interleukin-1 receptor antagonist balance modulate cardiac remodeling following myocardial infarction in the mouse.

    Directory of Open Access Journals (Sweden)

    Antonio Abbate

    Full Text Available Healing after acute myocardial infarction (AMI is characterized by an intense inflammatory response and increased Interleukin-1 (IL-1 tissue activity. Genetically engineered mice lacking the IL-1 receptor (IL-1R1-/-, not responsive to IL-1 or the IL-1 receptor antagonist (IL-1Ra, enhanced response to IL-1 have an altered IL-1/IL-1Ra balance that we hypothesize modulates infarct healing and cardiac remodeling after AMI.IL-1R1-/- and IL-1Ra-/- male mice and their correspondent wild-types (WT were subjected to permanent coronary artery ligation or sham surgery. Infarct size (trichrome scar size, apoptotic cell death (TUNEL and left ventricular (LV dimensions and function (echocardiography were measured prior to and 7 days after surgery.When compared with the corresponding WT, IL-1R1-/- mice had significantly smaller infarcts (-25%, less cardiomyocyte apoptosis (-50%, and reduced LV enlargement (LV end-diastolic diameter increase [LVEDD], -20% and dysfunction (LV ejection fraction [LVEF] decrease, -50%, whereas IL-1Ra-/- mice had significantly larger infarcts (+75%, more apoptosis (5-fold increase, and more severe LV enlargement (LVEDD increase,+30% and dysfunction (LVEF decrease, +70%(all P values <0.05.An imbalance in IL-1/IL-1Ra signaling at the IL-1R1 level modulates the severity of cardiac remodeling after AMI in the mouse, with reduced IL-1R1 signaling providing protection and unopposed IL-1R1 signaling providing harm.

  15. Electrically Induced Calcium Handling in Cardiac Progenitor Cells

    Science.gov (United States)

    Wagner, Mary B.

    2016-01-01

    For nearly a century, the heart was viewed as a terminally differentiated organ until the discovery of a resident population of cardiac stem cells known as cardiac progenitor cells (CPCs). It has been shown that the regenerative capacity of CPCs can be enhanced by ex vivo modification. Preconditioning CPCs could provide drastic improvements in cardiac structure and function; however, a systematic approach to determining a mechanistic basis for these modifications founded on the physiology of CPCs is lacking. We have identified a novel property of CPCs to respond to electrical stimulation by initiating intracellular Ca2+ oscillations. We used confocal microscopy and intracellular calcium imaging to determine the spatiotemporal properties of the Ca2+ signal and the key proteins involved in this process using pharmacological inhibition and confocal Ca2+ imaging. Our results provide valuable insights into mechanisms to enhance the therapeutic potential in stem cells and further our understanding of human CPC physiology.

  16. Targeted disruption of the heat shock protein 20–phosphodiesterase 4D (PDE4D interaction protects against pathological cardiac remodelling in a mouse model of hypertrophy

    Directory of Open Access Journals (Sweden)

    Tamara P. Martin

    2014-01-01

    Full Text Available Phosphorylated heat shock protein 20 (HSP20 is cardioprotective. Using human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs and a mouse model of pressure overload mediated hypertrophy, we show that peptide disruption of the HSP20–phosphodiesterase 4D (PDE4D complex results in attenuation of action potential prolongation and protection against adverse cardiac remodelling. The later was evidenced by improved contractility, decreased heart weight to body weight ratio, and reduced interstitial and perivascular fibrosis. This study demonstrates that disruption of the specific HSP20–PDE4D interaction leads to attenuation of pathological cardiac remodelling.

  17. Targeted disruption of the heat shock protein 20–phosphodiesterase 4D (PDE4D) interaction protects against pathological cardiac remodelling in a mouse model of hypertrophy

    Science.gov (United States)

    Martin, Tamara P.; Hortigon-Vinagre, Maria P.; Findlay, Jane E.; Elliott, Christina; Currie, Susan; Baillie, George S.

    2014-01-01

    Phosphorylated heat shock protein 20 (HSP20) is cardioprotective. Using human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) and a mouse model of pressure overload mediated hypertrophy, we show that peptide disruption of the HSP20–phosphodiesterase 4D (PDE4D) complex results in attenuation of action potential prolongation and protection against adverse cardiac remodelling. The later was evidenced by improved contractility, decreased heart weight to body weight ratio, and reduced interstitial and perivascular fibrosis. This study demonstrates that disruption of the specific HSP20–PDE4D interaction leads to attenuation of pathological cardiac remodelling. PMID:25426411

  18. Targeted disruption of the heat shock protein 20-phosphodiesterase 4D (PDE4D) interaction protects against pathological cardiac remodelling in a mouse model of hypertrophy.

    Science.gov (United States)

    Martin, Tamara P; Hortigon-Vinagre, Maria P; Findlay, Jane E; Elliott, Christina; Currie, Susan; Baillie, George S

    2014-01-01

    Phosphorylated heat shock protein 20 (HSP20) is cardioprotective. Using human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) and a mouse model of pressure overload mediated hypertrophy, we show that peptide disruption of the HSP20-phosphodiesterase 4D (PDE4D) complex results in attenuation of action potential prolongation and protection against adverse cardiac remodelling. The later was evidenced by improved contractility, decreased heart weight to body weight ratio, and reduced interstitial and perivascular fibrosis. This study demonstrates that disruption of the specific HSP20-PDE4D interaction leads to attenuation of pathological cardiac remodelling.

  19. Glucagon-like peptide-1 and the exenatide analogue AC3174 improve cardiac function, cardiac remodeling, and survival in rats with chronic heart failure

    Directory of Open Access Journals (Sweden)

    Polizzi Clara

    2010-11-01

    Full Text Available Abstract Background Accumulating evidence suggests glucagon-like peptide-1 (GLP-1 exerts cardioprotective effects in animal models of myocardial infarction (MI. We hypothesized that chronic treatment with GLP-1 or the exenatide analog AC3174 would improve cardiac function, cardiac remodeling, insulin sensitivity, and exercise capacity (EC in rats with MI-induced chronic heart failure (CHF caused by coronary artery ligation. Methods Two weeks post-MI, male Sprague-Dawley rats were treated with GLP-1 (2.5 or 25 pmol/kg/min, AC3174 (1.7 or 5 pmol/kg/min or vehicle via subcutaneous infusion for 11 weeks. Cardiac function and morphology were assessed by echocardiography during treatment. Metabolic, hemodynamic, exercise-capacity, and body composition measurements were made at study end. Results Compared with vehicle-treated rats with CHF, GLP-1 or AC3174 significantly improved cardiac function, including left ventricular (LV ejection fraction, and end diastolic pressure. Cardiac dimensions also improved as evidenced by reduced LV end diastolic and systolic volumes and reduced left atrial volume. Vehicle-treated CHF rats exhibited fasting hyperglycemia and hyperinsulinemia. In contrast, GLP-1 or AC3174 normalized fasting plasma insulin and glucose levels. GLP-1 or AC3174 also significantly reduced body fat and fluid mass and improved exercise capacity and respiratory efficiency. Four of 16 vehicle control CHF rats died during the study compared with 1 of 44 rats treated with GLP-1 or AC3174. The cellular mechanism by which GLP-1 or AC3174 exert cardioprotective effects appears unrelated to changes in GLUT1 or GLUT4 translocation or expression. Conclusions Chronic treatment with either GLP-1 or AC3174 showed promising cardioprotective effects in a rat model of CHF. Hence, GLP-1 receptor agonists may represent a novel approach for the treatment of patients with CHF or cardiovascular disease associated with type 2 diabetes.

  20. Renin inhibition improves cardiac function and remodeling after myocardial infarction independent of blood pressure

    NARCIS (Netherlands)

    D. Westermann (Dirk); A. Riad (Alexander); O. Lettau (Olga); A.J.M. Roks (Anton); K. Sawatis (Konstantinos); P.M. Becher (Peter Moritz); F. Escher (Felicitas); A.H.J. Danser (Jan); H.P. Schultheiss (Heinz-Peter); C. Tschöpe (Carsten)

    2008-01-01

    textabstractPharmacological renin inhibition with aliskiren is an effective antihypertensive drug treatment, but it is currently unknown whether aliskiren is able to attenuate cardiac failure independent of its blood pressure-lowering effects. We investigated the effect of aliskiren on cardiac remod

  1. Low-level transcutaneous electrical stimulation of the auricular branch of vagus nerve ameliorates left ventricular remodeling and dysfunction by downregulation of matrix metalloproteinase 9 and transforming growth factor β1.

    Science.gov (United States)

    Wang, Zhuo; Yu, Lilei; Huang, Bing; Wang, Songyun; Liao, Kai; Saren, Gaowa; Zhou, Xiaoya; Jiang, Hong

    2015-04-01

    Vagus nerve stimulation improves left ventricular (LV) remodeling by downregulation of matrix metalloproteinase 9 (MMP-9) and transforming growth factor β1 (TGF-β1). Our previous study found that low-level transcutaneous electrical stimulation of the auricular branch of the vagus nerve (LL-TS) could be substituted for vagus nerve stimulation to reverse cardiac remodeling. So, we hypothesize that LL-TS could ameliorate LV remodeling by regulation of MMP-9 and TGF-β1 after myocardial infarction (MI). Twenty-two beagle dogs were randomly divided into a control group (MI was induced by permanent ligation of the left coronary artery, n = 8), an LL-TS group (MI with long-term intermittent LL-TS, n = 8), and a normal group (sham ligation without stimulation, n = 6). At the end of 6 weeks follow-up, LL-TS significantly reduced LV end-systolic and end-diastolic dimensions, improved ejection fraction and ratio of early (E) to late (A) peak mitral inflow velocity. LL-TS attenuated interstitial fibrosis and collagen degradation in the noninfarcted myocardium compared with the control group. Elevated level of MMP-9 and TGF-β1 in LV tissue and peripheral plasma were diminished in the LL-TS treated dogs. LL-TS improves cardiac function and prevents cardiac remodeling in the late stages after MI by downregulation of MMP-9 and TGF-β1 expression.

  2. Cardiac remodeling following percutaneous mitral valve repair - initial results assessed by cardiovascular magnetic resonance imaging

    DEFF Research Database (Denmark)

    Radunski, U K; Franzen, O; Barmeyer, A

    2014-01-01

    (CMR) to assess reverse myocardial remodeling in patients after MitraClip implantation. MATERIALS AND METHODS: 12 patients underwent CMR at baseline (BL) before and at 6 months follow-up (FU) after MitraClip implantation. Cine-CMR was performed in short- and long-axes for the assessment of left...

  3. Low carbohydrate/high-fat diet attenuates cardiac hypertrophy, remodeling, and altered gene expression in hypertension

    Science.gov (United States)

    The effects of dietary fat intake on the development of left ventricular hypertrophy and accompanying structural and molecular remodeling in response to hypertension are not understood. The present study compared the effects of a high-fat versus a low-fat diet on development of left ventricular hype...

  4. Sudden cardiac death in dogs with remodeled hearts is associated with larger beat-to-beat variability of repolarization

    DEFF Research Database (Denmark)

    Thomsen, Morten Bækgaard; Truin, Michiel; van Opstal, Jurren M

    2005-01-01

    Increased proarrhythmia in dogs with chronic AV block (AVB) has been explained by ventricular remodeling causing a decrease in repolarization reserve. Beat-to-beat variability of repolarization (BVR) has been suggested to reflect repolarization reserve, in which high variability represents...... diminished reserve and larger propensity for repolarization-dependent ventricular arrhythmia. A subset of chronic AVB dogs (10%) suffers sudden cardiac death (SCD). With the assumption that repolarization defects constitute a potentially lethal proarrhythmic substrate, we hypothesized that BVR in SCD dogs...... are larger than in matched control chronic AVB dogs. From a population of 200 chronic AVB dogs, initially two groups were chosen retrospectively: 8 dogs that died suddenly (SCD) and 8 control dogs. Control dogs had a longer lifespan after AVB (10 to 18 weeks) than SCD dogs (5 to 10 weeks). All dogs had...

  5. Cardiac remodeling during and after renin-angiotensin system stimulation in Cyp1a1-Ren2 transgenic rats

    DEFF Research Database (Denmark)

    Heijnen, Bart Fj; Pelkmans, Leonie Pj; Danser, Ah Jan

    2013-01-01

    . Hypertrophic genes were highly upregulated, whereas in substantial activation a fibrotic response was absent. Four weeks after withdrawal of I3C, (pro)renin levels were normalized in all IHR. While in adult IHR BP returned to normal, hypertension was sustained in young IHR. Despite the latter, myocardial...... administration of indole-3-carbinol (I3C). Young (four-weeks old) and adult (30-weeks old) IHR were fed I3C for four weeks (leading to systolic BP >200 mmHg). RAS-stimulation was stopped and animals were followed-up for a consecutive period. Cardiac function and geometry was determined echocardiographically...... hypertrophy was fully regressed in both young and adult IHR. We conclude that (pro)renin-induced severe hypertension in IHR causes an age-independent fully reversible myocardial concentric hypertrophic remodeling, despite a continued elevated BP in young IHR....

  6. Deficiency of ataxia telangiectasia mutated kinase modulates cardiac remodeling following myocardial infarction: involvement in fibrosis and apoptosis.

    Directory of Open Access Journals (Sweden)

    Cerrone R Foster

    Full Text Available Ataxia telangiectasia mutated kinase (ATM is a cell cycle checkpoint protein activated in response to DNA damage. We recently reported that ATM plays a protective role in myocardial remodeling following β-adrenergic receptor stimulation. Here we investigated the role of ATM in cardiac remodeling using myocardial infarction (MI as a model.Left ventricular (LV structure, function, apoptosis, fibrosis, and protein levels of apoptosis- and fibrosis-related proteins were examined in wild-type (WT and ATM heterozygous knockout (hKO mice 7 days post-MI. Infarct sizes were similar in both MI groups. However, infarct thickness was higher in hKO-MI group. Two dimensional M-mode echocardiography revealed decreased percent fractional shortening (%FS and ejection fraction (EF in both MI groups when compared to their respective sham groups. However, the decrease in %FS and EF was significantly greater in WT-MI vs hKO-MI. LV end systolic and diastolic diameters were greater in WT-MI vs hKO-MI. Fibrosis, apoptosis, and α-smooth muscle actin staining was significantly higher in hKO-MI vs WT-MI. MMP-2 protein levels and activity were increased to a similar extent in the infarct regions of both groups. MMP-9 protein levels were increased in the non-infarct region of WT-MI vs WT-sham. MMP-9 protein levels and activity were significantly lower in the infarct region of WT vs hKO. TIMP-2 protein levels similarly increased in both MI groups, whereas TIMP-4 protein levels were significantly lower in the infarct region of hKO group. Phosphorylation of p53 protein was higher, while protein levels of manganese superoxide dismutase were significantly lower in the infarct region of hKO vs WT. In vitro, inhibition of ATM using KU-55933 increased oxidative stress and apoptosis in cardiac myocytes.

  7. Left ventricular geometric remodeling in relation to non-ischemic scar pattern on cardiac magnetic resonance imaging.

    Science.gov (United States)

    Kim, Jiwon; Kochav, Jonathan D; Gurevich, Sergey; Afroz, Anika; Petashnick, Maya; Volo, Samuel; Diaz, Belen; Okin, Peter M; Horn, Evelyn; Devereux, Richard B; Weinsaft, Jonathan W

    2014-12-01

    Left ventricular (LV) remodeling and myocardial fibrosis have been linked to adverse heart failure outcomes. Mid wall late gadolinium enhancement (MW-LGE) on cardiac magnetic resonance (CMR) imaging is well-associated with non-ischemic cardiomyopathy (NICM), but prevalence in ischemic cardiomyopathy (ICM) and association with remodeling are unknown. The population comprised patients with systolic dysfunction [LV ejection fraction (LVEF ≤ 40 %)]. CMR was used to identify MW-LGE, conventionally defined as fibrosis of the mid-myocardial or epicardial aspect of the LV septum. 285 patients were studied. MW-LGE was present in 12 %, and was tenfold more common with NICM (32 %) versus ICM (3 %, p MW-LGE had ICM. LV wall stress was higher (p = 0.02) among patients with, versus those without, MW-LGE despite similar systolic blood pressure (p = 0.24). In multivariate analysis, MW-LGE was associated with CMR-quantified LV end-diastolic volume (p = 0.03) independent of LVEF and mass. Incorporation of clinical and imaging variables demonstrated MW-LGE to be associated with higher LV end-diastolic volume (OR 1.13, CI 1.004-1.27 per 10 ml/m(2), p = 0.04) after controlling for presence of NICM (OR 16.0, CI 5.8-44.1, p MW-LGE can occur in ICM and is a marker of LV chamber dilation irrespective of cardiomyopathic etiology.

  8. Practical aspects of cardiac tissue engineering with electrical stimulation.

    Science.gov (United States)

    Cannizzaro, Christopher; Tandon, Nina; Figallo, Elisa; Park, Hyoungshin; Gerecht, Sharon; Radisic, Milica; Elvassore, Nicola; Vunjak-Novakovic, Gordana

    2007-01-01

    Heart disease is a leading cause of death in western society. Despite the success of heart transplantation, a chronic shortage of donor organs, along with the associated immunological complications of this approach, demands that alternative treatments be found. One such option is to repair, rather than replace, the heart with engineered cardiac tissue. Multiple studies have shown that to attain functional tissue, assembly signaling cues must be recapitulated in vitro. In their native environment, cardiomyocytes are directed to beat in synchrony by propagation of pacing current through the tissue. Recently, we have shown that electrical stimulation directs neonatal cardiomyocytes to assemble into native-like tissue in vitro. This chapter provides detailed methods we have employed in taking this "biomimetic" approach. After an initial discussion on how electric field stimulation can influence cell behavior, we examine the practical aspects of cardiac tissue engineering with electrical stimulation, such as electrode selection and cell seeding protocols, and conclude with what we feel are the remaining challenges to be overcome.

  9. TWEAK-Fn14 cytokine-receptor axis: a new player of myocardial remodeling and cardiac failure

    Directory of Open Access Journals (Sweden)

    Tatyana eNovoyatleva

    2014-02-01

    Full Text Available Tumor necrosis factor (TNF has been firmly established as a pathogenic factor in heart failure, a significant socio-economic burden. In this review we will explore the role of other members of the TNF/TNF receptor superfamily (TNFSF/TNFRSF in cardiovascular diseases (CVDs focusing on TWEAK and its receptor Fn14, new players in myocardial remodeling and heart failure. The TWEAK/Fn14 pathway controls a variety of cellular activities such as proliferation, differentiation and apoptosis and has diverse biological functions in pathological mechanisms like inflammation and fibrosis that are associated with CVDs. Furthermore, it has recently been shown that the TWEAK/Fn14 axis is a positive regulator of cardiac hypertrophy and that deletion of Fn14 receptor protects from right heart fibrosis and dysfunction. We discuss the potential use of the TWEAK/Fn14 axis as biomarker for CVDs as well as therapeutic target for future treatment of human heart failure based on supporting data from animal models and in vitro studies. Collectively, existing data strongly suggest the TWEAK/Fn14 axis as a potential new therapeutic target for achieving cardiac protection in patients with CVDs.

  10. Adenosine A2A receptor agonist prevents cardiac remodeling and dysfunction in spontaneously hypertensive male rats after myocardial infarction

    Science.gov (United States)

    da Silva, Jaqueline S; Gabriel-Costa, Daniele; Sudo, Roberto T; Wang, Hao; Groban, Leanne; Ferraz, Emanuele B; Nascimento, José Hamilton M; Fraga, Carlos Alberto M; Barreiro, Eliezer J; Zapata-Sudo, Gisele

    2017-01-01

    Background This work evaluated the hypothesis that 3,4-methylenedioxybenzoyl-2-thienylhydrazone (LASSBio-294), an agonist of adenosine A2A receptor, could be beneficial for preventing cardiac dysfunction due to hypertension associated with myocardial infarction (MI). Methods Male spontaneously hypertensive rats (SHR) were randomly divided into four groups (six animals per group): sham-operation (SHR-Sham), and myocardial infarction rats (SHR-MI) were treated orally either with vehicle or LASSBio-294 (10 and 20 mg.kg−1.d−1) for 4 weeks. Echocardiography and in vivo hemodynamic parameters measured left ventricle (LV) structure and function. Exercise tolerance was evaluated using a treadmill test. Cardiac remodeling was accessed by LV collagen deposition and tumor necrosis factor α expression. Results Early mitral inflow velocity was significantly reduced in the SHR-MI group, and there was significant recovery in a dose-dependent manner after treatment with LASSBio-294. Exercise intolerance observed in the SHR-MI group was prevented by 10 mg.kg−1.d−1 of LASS-Bio-294, and exercise tolerance exceeded that of the SHR-Sham group at 20 mg.kg−1.d−1. LV end-diastolic pressure increased after MI, and this was prevented by 10 and 20 mg.kg−1.d−1 of LASSBio-294. Sarcoplasmic reticulum Ca2+ ATPase levels were restored in a dose-dependent manner after treatment with LASSBio-294. Fibrosis and inflammatory processes were also counteracted by LASSBio-294, with reductions in LV collagen deposition and tumor necrosis factor α expression. Conclusion In summary, oral administration of LASSBio-294 after MI in a dose-dependent manner prevented the development of cardiac dysfunction, demonstrating this compound’s potential as an alternative treatment for heart failure in the setting of ischemic heart disease with superimposed chronic hypertension.

  11. High intensity interval and endurance training have opposing effects on markers of heart failure and cardiac remodeling in hypertensive rats.

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    Tanya M Holloway

    Full Text Available There has been re-emerging interest and significant work dedicated to investigating the metabolic effects of high intensity interval training (HIIT in recent years. HIIT is considered to be a time efficient alternative to classic endurance training (ET that elicits similar metabolic responses in skeletal muscle. However, there is a lack of information on the impact of HIIT on cardiac muscle in disease. Therefore, we determined the efficacy of ET and HIIT to alter cardiac muscle characteristics involved in the development of diastolic dysfunction, such as ventricular hypertrophy, fibrosis and angiogenesis, in a well-established rodent model of hypertension-induced heart failure before the development of overt heart failure. ET decreased left ventricle fibrosis by ~40% (P < 0.05, and promoted a 20% (P<0.05 increase in the left ventricular capillary/fibre ratio, an increase in endothelial nitric oxide synthase protein (P<0.05, and a decrease in hypoxia inducible factor 1 alpha protein content (P<0.05. In contrast, HIIT did not decrease existing fibrosis, and HIIT animals displayed a 20% increase in left ventricular mass (P<0.05 and a 20% decrease in cross sectional area (P<0.05. HIIT also increased brain natriuretic peptide by 50% (P<0.05, in the absence of concomitant angiogenesis, strongly suggesting pathological cardiac remodeling. The current data support the longstanding belief in the effectiveness of ET in hypertension. However, HIIT promoted a pathological adaptation in the left ventricle in the presence of hypertension, highlighting the need for further research on the widespread effects of HIIT in the presence of disease.

  12. S-diclofenac Protects against Doxorubicin-Induced Cardiomyopathy in Mice via Ameliorating Cardiac Gap Junction Remodeling

    Science.gov (United States)

    Zhang, Huili; Zhang, Alian; Guo, Changfa; Shi, Chunzhi; Zhang, Yang; Liu, Qing; Sparatore, Anna; Wang, Changqian

    2011-01-01

    Hydrogen sulfide (H2S), as a novel gaseous mediator, plays important roles in mammalian cardiovascular tissues. In the present study, we investigated the cardioprotective effect of S-diclofenac (2-[(2,6-dichlorophenyl)amino] benzeneacetic acid 4-(3H-1,2,dithiol-3-thione-5-yl)phenyl ester), a novel H2S-releasing derivative of diclofenac, in a murine model of doxorubicin-induced cardiomyopathy. After a single dose injection of doxorubicin (15 mg/kg, i.p.), male C57BL/6J mice were given daily treatment of S-diclofenac (25 and 50 µmol/kg, i.p.), diclofenac (25 and 50 µmol/kg, i.p.), NaHS (50 µmol/kg, i.p.), or same volume of vehicle. The cardioprotective effect of S-diclofenac was observed after 14 days. It showed that S-diclofenac, but not diclofenac, dose-dependently inhibited the doxorubicin-induced downregulation of cardiac gap junction proteins (connexin 43 and connexin 45) and thus reversed the remodeling of gap junctions in hearts. It also dose-dependently suppressed doxorubicin-induced activation of JNK in hearts. Furthermore, S-diclofenac produced a dose-dependent anti-inflammatory and anti-oxidative effect in this model. As a result, S-diclofenac significantly attenuated doxorubicin-related cardiac injury and cardiac dysfunction, and improved the survival rate of mice with doxorubicin-induced cardiomyopathy. These effects of S-diclofenac were mimicked in large part by NaHS. Therefore, we propose that H2S released from S-diclofenac in vivo contributes to the protective effect in doxorubicin-induced cardiomyopathy. These data also provide evidence for a critical role of H2S in the pathogenesis of doxorubicin-induced cardiomyopathy. PMID:22039489

  13. S-diclofenac protects against doxorubicin-induced cardiomyopathy in mice via ameliorating cardiac gap junction remodeling.

    Directory of Open Access Journals (Sweden)

    Huili Zhang

    Full Text Available Hydrogen sulfide (H(2S, as a novel gaseous mediator, plays important roles in mammalian cardiovascular tissues. In the present study, we investigated the cardioprotective effect of S-diclofenac (2-[(2,6-dichlorophenylamino] benzeneacetic acid 4-(3H-1,2,dithiol-3-thione-5-ylphenyl ester, a novel H(2S-releasing derivative of diclofenac, in a murine model of doxorubicin-induced cardiomyopathy. After a single dose injection of doxorubicin (15 mg/kg, i.p., male C57BL/6J mice were given daily treatment of S-diclofenac (25 and 50 µmol/kg, i.p., diclofenac (25 and 50 µmol/kg, i.p., NaHS (50 µmol/kg, i.p., or same volume of vehicle. The cardioprotective effect of S-diclofenac was observed after 14 days. It showed that S-diclofenac, but not diclofenac, dose-dependently inhibited the doxorubicin-induced downregulation of cardiac gap junction proteins (connexin 43 and connexin 45 and thus reversed the remodeling of gap junctions in hearts. It also dose-dependently suppressed doxorubicin-induced activation of JNK in hearts. Furthermore, S-diclofenac produced a dose-dependent anti-inflammatory and anti-oxidative effect in this model. As a result, S-diclofenac significantly attenuated doxorubicin-related cardiac injury and cardiac dysfunction, and improved the survival rate of mice with doxorubicin-induced cardiomyopathy. These effects of S-diclofenac were mimicked in large part by NaHS. Therefore, we propose that H(2S released from S-diclofenac in vivo contributes to the protective effect in doxorubicin-induced cardiomyopathy. These data also provide evidence for a critical role of H(2S in the pathogenesis of doxorubicin-induced cardiomyopathy.

  14. Electrical remodeling of preoptic GABAergic neurons involves the Kv1.5 subunit.

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    Iustin V Tabarean

    Full Text Available The electrogenic machinery of an excitable cell can adapt in response to changes in input, genetic deficit or in pathological conditions, however the underlying molecular mechanisms are not understood. In cases of genetic deletion it is commonly observed that a channel subunit from the same family replaces the missing one. We have previously reported that Kv4.2-/- preoptic GABAergic neurons display identical firing characteristics to those of wild-type neurons despite having reduced A-type currents, and that, surprisingly, they present a robust upregulation of a delayed rectifier current, the nature of which is unknown. Here, using pharmacology, qPCR and Western blots we report that, although the wild-type neurons express several Kv subunits, the upregulated current is conducted by the Kv1.5 subunit exclusively. Thus, this study reveals the molecular nature of a novel mechanism of electrical remodeling in central neurons.

  15. High molecular weight fibroblast growth factor-2 in the human heart is a potential target for prevention of cardiac remodeling.

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    Jon-Jon Santiago

    Full Text Available Fibroblast growth factor 2 (FGF-2 is a multifunctional protein synthesized as high (Hi- and low (Lo- molecular weight isoforms. Studies using rodent models showed that Hi- and Lo-FGF-2 exert distinct biological activities: after myocardial infarction, rat Lo-FGF-2, but not Hi-FGF-2, promoted sustained cardioprotection and angiogenesis, while Hi-FGF-2, but not Lo-FGF-2, promoted myocardial hypertrophy and reduced contractile function. Because there is no information regarding Hi-FGF-2 in human myocardium, we undertook to investigate expression, regulation, secretion and potential tissue remodeling-associated activities of human cardiac (atrial Hi-FGF-2. Human patient-derived atrial tissue extracts, as well as pericardial fluid, contained Hi-FGF-2 isoforms, comprising, respectively, 53%(±20 SD and 68% (±25 SD of total FGF-2, assessed by western blotting. Human atrial tissue-derived primary myofibroblasts (hMFs expressed and secreted predominantly Hi-FGF-2, at about 80% of total. Angiotensin II (Ang II up-regulated Hi-FGF-2 in hMFs, via activation of both type 1 and type 2 Ang II receptors; the ERK pathway; and matrix metalloprotease-2. Treatment of hMFs with neutralizing antibodies selective for human Hi-FGF-2 (neu-AbHi-FGF-2 reduced accumulation of proteins associated with fibroblast-to-myofibroblast conversion and fibrosis, including α-smooth muscle actin, extra-domain A fibronectin, and procollagen. Stimulation of hMFs with recombinant human Hi-FGF-2 was significantly more potent than Lo-FGF-2 in upregulating inflammation-associated proteins such as pro-interleukin-1β and plasminogen-activator-inhibitor-1. Culture media conditioned by hMFs promoted cardiomyocyte hypertrophy, an effect that was prevented by neu-AbHi-FGF-2 in vitro. In conclusion, we have documented that Hi-FGF-2 represents a substantial fraction of FGF-2 in human cardiac (atrial tissue and in pericardial fluid, and have shown that human Hi-FGF-2, unlike Lo-FGF-2, promotes

  16. Modest elevation in BNP in asymptomatic hypertensive patients reflects sub-clinical cardiac remodeling, inflammation and extracellular matrix changes.

    LENUS (Irish Health Repository)

    Phelan, Dermot

    2012-11-01

    In asymptomatic subjects B-type natriuretic peptide (BNP) is associated with adverse cardiovascular outcomes even at levels well below contemporary thresholds used for the diagnosis of heart failure. The mechanisms behind these observations are unclear. We examined the hypothesis that in an asymptomatic hypertensive population BNP would be associated with sub-clinical evidence of cardiac remodeling, inflammation and extracellular matrix (ECM) alterations. We performed transthoracic echocardiography and sampled coronary sinus (CS) and peripheral serum from patients with low (n = 14) and high BNP (n = 27). Peripheral BNP was closely associated with CS levels (r = 0.92, p<0.001). CS BNP correlated significantly with CS levels of markers of collagen type I and III turnover including: PINP (r = 0.44, p = 0.008), CITP (r = 0.35, p = 0.03) and PIIINP (r = 0.35, p = 0.001), and with CS levels of inflammatory cytokines including: TNF-α (r = 0.49, p = 0.002), IL-6 (r = 0.35, p = 0.04), and IL-8 (r = 0.54, p<0.001). The high BNP group had greater CS expression of fibro-inflammatory biomarkers including: CITP (3.8±0.7 versus 5.1±1.9, p = 0.007), TNF-α (3.2±0.5 versus 3.7±1.1, p = 003), IL-6 (1.9±1.3 versus 3.4±2.7, p = 0.02) and hsCRP (1.2±1.1 versus 2.4±1.1, p = 0.04), and greater left ventricular mass index (97±20 versus 118±26 g\\/m(2), p = 0.03) and left atrial volume index (18±2 versus 21±4, p = 0.008). Our data provide insight into the mechanisms behind the observed negative prognostic impact of modest elevations in BNP and suggest that in an asymptomatic hypertensive cohort a peripheral BNP measurement may be a useful marker of an early, sub-clinical pathological process characterized by cardiac remodeling, inflammation and ECM alterations.

  17. Modest elevation in BNP in asymptomatic hypertensive patients reflects sub-clinical cardiac remodeling, inflammation and extracellular matrix changes.

    Directory of Open Access Journals (Sweden)

    Dermot Phelan

    Full Text Available In asymptomatic subjects B-type natriuretic peptide (BNP is associated with adverse cardiovascular outcomes even at levels well below contemporary thresholds used for the diagnosis of heart failure. The mechanisms behind these observations are unclear. We examined the hypothesis that in an asymptomatic hypertensive population BNP would be associated with sub-clinical evidence of cardiac remodeling, inflammation and extracellular matrix (ECM alterations. We performed transthoracic echocardiography and sampled coronary sinus (CS and peripheral serum from patients with low (n = 14 and high BNP (n = 27. Peripheral BNP was closely associated with CS levels (r = 0.92, p<0.001. CS BNP correlated significantly with CS levels of markers of collagen type I and III turnover including: PINP (r = 0.44, p = 0.008, CITP (r = 0.35, p = 0.03 and PIIINP (r = 0.35, p = 0.001, and with CS levels of inflammatory cytokines including: TNF-α (r = 0.49, p = 0.002, IL-6 (r = 0.35, p = 0.04, and IL-8 (r = 0.54, p<0.001. The high BNP group had greater CS expression of fibro-inflammatory biomarkers including: CITP (3.8±0.7 versus 5.1±1.9, p = 0.007, TNF-α (3.2±0.5 versus 3.7±1.1, p = 003, IL-6 (1.9±1.3 versus 3.4±2.7, p = 0.02 and hsCRP (1.2±1.1 versus 2.4±1.1, p = 0.04, and greater left ventricular mass index (97±20 versus 118±26 g/m(2, p = 0.03 and left atrial volume index (18±2 versus 21±4, p = 0.008. Our data provide insight into the mechanisms behind the observed negative prognostic impact of modest elevations in BNP and suggest that in an asymptomatic hypertensive cohort a peripheral BNP measurement may be a useful marker of an early, sub-clinical pathological process characterized by cardiac remodeling, inflammation and ECM alterations.

  18. Metabolic Syndrome Remodels Electrical Activity of the Sinoatrial Node and Produces Arrhythmias in Rats

    Science.gov (United States)

    Albarado-Ibañez, Alondra; Avelino-Cruz, José Everardo; Velasco, Myrian; Torres-Jácome, Julián; Hiriart, Marcia

    2013-01-01

    In the last ten years, the incidences of metabolic syndrome and supraventricular arrhythmias have greatly increased. The metabolic syndrome is a cluster of alterations, which include obesity, hypertension, hypertriglyceridemia, glucose intolerance and insulin resistance, that increase the risk of developing, among others, atrial and nodal arrhythmias. The aim of this study is to demonstrate that metabolic syndrome induces electrical remodeling of the sinus node and produces arrhythmias. We induced metabolic syndrome in 2-month-old male Wistar rats by administering 20% sucrose in the drinking water. Eight weeks later, the rats were anesthetized and the electrocardiogram was recorded, revealing the presence of arrhythmias only in treated rats. Using conventional microelectrode and voltage clamp techniques, we analyzed the electrical activity of the sinoatrial node. We observed that in the sinoatrial node of “metabolic syndrome rats”, compared to controls, the spontaneous firing of all cells decreased, while the slope of the diastolic depolarization increased only in latent pacemaker cells. Accordingly, the pacemaker currents If and Ist increased. Furthermore, histological analysis showed a large amount of fat surrounding nodal cardiomyocytes and a rise in the sympathetic innervation. Finally, Poincaré plot denoted irregularity in the R-R and P-P ECG intervals, in agreement with the variability of nodal firing potential recorded in metabolic syndrome rats. We conclude that metabolic syndrome produces a dysfunction SA node by disrupting normal architecture and the electrical activity, which could explain the onset of arrhythmias in rats. PMID:24250786

  19. Salvianolic acid A, a novel matrix metalloproteinase-9 inhibitor, prevents cardiac remodeling in spontaneously hypertensive rats.

    Directory of Open Access Journals (Sweden)

    Baohong Jiang

    Full Text Available Cardiac fibrosis is a deleterious consequence of hypertension which may further advance to heart failure and increased matrix metalloproteinase-9 (MMP-9 contributes to the underlying mechanism. Therefore, new therapeutic strategies to attenuate the effects of MMP-9 are urgently needed. In the present study, we characterize salvianolic acid A (SalA as a novel MMP-9 inhibitor at molecular, cellular and animal level. We expressed a truncated form of MMP-9 which contains only the catalytic domain (MMP-9 CD, and used this active protein for enzymatic kinetic analysis and Biacore detection. Data generated from these assays indicated that SalA functioned as the strongest competitive inhibitor of MMP-9 among 7 phenolic acids from Salvia miltiorrhiza. In neonatal cardiac fibroblast, SalA inhibited fibroblast migration, blocked myofibroblast transformation, inhibited secretion of intercellular adhesion molecule (ICAM, interleukin-6 (IL-6 and soluble vascular cell adhesion molecule-1 (sVCAM-1 as well as collagen induced by MMP-9 CD. Functional effects of SalA inhibition on MMP-9 was further confirmed in cultured cardiac H9c2 cell overexpressing MMP-9 in vitro and in heart of spontaneously hypertensive rats (SHR in vivo. Moreover, SalA treatment in SHR resulted in decreased heart fibrosis and attenuated heart hypertrophy. These results indicated that SalA is a novel inhibitor of MMP-9, thus playing an inhibitory role in hypertensive fibrosis. Further studies to develop SalA and its analogues for their potential clinical application of cardioprotection are warranted.

  20. Salvianolic Acid A, a Novel Matrix Metalloproteinase-9 Inhibitor, Prevents Cardiac Remodeling in Spontaneously Hypertensive Rats

    Science.gov (United States)

    Deng, Yanping; Teng, Fukang; Chen, Jing; Xue, Song; Kong, Xiangqian; Luo, Cheng; Shen, Xu; Jiang, Hualiang; Xu, Feng; Yang, Wengang; Yin, Jun; Wang, Yanhui; Chen, Hui; Wu, Wanying; Liu, Xuan; Guo, De-an

    2013-01-01

    Cardiac fibrosis is a deleterious consequence of hypertension which may further advance to heart failure and increased matrix metalloproteinase-9 (MMP-9) contributes to the underlying mechanism. Therefore, new therapeutic strategies to attenuate the effects of MMP-9 are urgently needed. In the present study, we characterize salvianolic acid A (SalA) as a novel MMP-9 inhibitor at molecular, cellular and animal level. We expressed a truncated form of MMP-9 which contains only the catalytic domain (MMP-9 CD), and used this active protein for enzymatic kinetic analysis and Biacore detection. Data generated from these assays indicated that SalA functioned as the strongest competitive inhibitor of MMP-9 among 7 phenolic acids from Salvia miltiorrhiza. In neonatal cardiac fibroblast, SalA inhibited fibroblast migration, blocked myofibroblast transformation, inhibited secretion of intercellular adhesion molecule (ICAM), interleukin-6 (IL-6) and soluble vascular cell adhesion molecule-1 (sVCAM-1) as well as collagen induced by MMP-9 CD. Functional effects of SalA inhibition on MMP-9 was further confirmed in cultured cardiac H9c2 cell overexpressing MMP-9 in vitro and in heart of spontaneously hypertensive rats (SHR) in vivo. Moreover, SalA treatment in SHR resulted in decreased heart fibrosis and attenuated heart hypertrophy. These results indicated that SalA is a novel inhibitor of MMP-9, thus playing an inhibitory role in hypertensive fibrosis. Further studies to develop SalA and its analogues for their potential clinical application of cardioprotection are warranted. PMID:23533637

  1. Dominant negative Ras attenuates pathological ventricular remodeling in pressure overload cardiac hypertrophy

    Science.gov (United States)

    Ramos-Kuri, Manuel; Rapti, Kleopatra; Mehel, Hind; Zhang, Shihong; Dhandapany, Perundurai S.; Liang, Lifan; García-Carrancá, Alejandro; Bobe, Regis; Fischmeister, Rodolphe; Adnot, Serge; Lebeche, Djamel; Hajjar, Roger J.; Lipskaia, Larissa; Chemaly, Elie R.

    2015-01-01

    The importance of the oncogene Ras in cardiac hypertrophy is well appreciated. The hypertrophic effects of the constitutively active mutant Ras-Val12 are revealed by clinical syndromes due to the Ras mutations and experimental studies. We examined the possible anti-hypertrophic effect of Ras inhibition in vitro using rat neonatal cardiomyocytes (NRCM) and in vivo in the setting of pressure-overload left ventricular (LV) hypertrophy (POH) in rats. Ras functions were modulated via adenovirus directed gene transfer of active mutant Ras-Val12 or dominant negative mutant N17-DN-Ras (DN-Ras). Ras-Val12 expression in vitro activates NFAT resulting in pro-hypertrophic and cardio-toxic effects on NRCM beating and Z-line organization. In contrast, the DN-Ras was antihypertrophic on NRCM, inhibited NFAT and exerted cardio-protective effects attested by preserved NRCM beating and Z line structure. Additional experiments with silencing H-Ras gene strategy corroborated the antihypertrophic effects of siRNA-H-Ras on NRCM. In vivo, with the POH model, both Ras mutants were associated with similar hypertrophy two weeks after simultaneous induction of POH and Ras-mutant gene transfer. However, LV diameters were higher and LV fractional shortening lower in the Ras-Val12 group compared to control and DN-Ras. Moreover, DN-Ras reduced the cross-sectional area of cardiomyocytes in vivo, and decreased the expression of markers of pathologic cardiac hypertrophy. In isolated adult cardiomyocytes after 2 weeks of POH and Ras-mutant gene transfer, DN-Ras improved sarcomere shortening and calcium transients compared to Ras-Val12. Overall, DN-Ras promotes a more physiological form of hypertrophy, suggesting an interesting therapeutic target for pathological cardiac hypertrophy. PMID:26260012

  2. (Prorenin receptor triggers distinct angiotensin II-independent extracellular matrix remodeling and deterioration of cardiac function.

    Directory of Open Access Journals (Sweden)

    Anne-Mari Moilanen

    Full Text Available BACKGROUND: Activation of the renin-angiotensin-system (RAS plays a key pathophysiological role in heart failure in patients with hypertension and myocardial infarction. However, the function of (prorenin receptor ((PRR is not yet solved. We determined here the direct functional and structural effects of (PRR in the heart. METHODOLOGY/PRINCIPAL FINDINGS: (PRR was overexpressed by using adenovirus-mediated gene delivery in normal adult rat hearts up to 2 weeks. (PRR gene delivery into the anterior wall of the left ventricle decreased ejection fraction (P<0.01, fractional shortening (P<0.01, and intraventricular septum diastolic and systolic thickness, associated with approximately 2-fold increase in left ventricular (PRR protein levels at 2 weeks. To test whether the worsening of cardiac function and structure by (PRR gene overexpression was mediated by angiotensin II (Ang II, we infused an AT(1 receptor blocker losartan via osmotic minipumps. Remarkably, cardiac function deteriorated in losartan-treated (PRR overexpressing animals as well. Intramyocardial (PRR gene delivery also resulted in Ang II-independent activation of extracellular-signal-regulated kinase1/2 phosphorylation and myocardial fibrosis, and the expression of transforming growth factor-β1 and connective tissue growth factor genes. In contrast, activation of heat shock protein 27 phosphorylation and apoptotic cell death by (PRR gene delivery was Ang II-dependent. Finally, (PRR overexpression significantly increased direct protein-protein interaction between (PRR and promyelocytic zinc-finger protein. CONCLUSIONS/SIGNIFICANCE: These results indicate for the first time that (PRR triggers distinct Ang II-independent myocardial fibrosis and deterioration of cardiac function in normal adult heart and identify (PRR as a novel therapeutic target to optimize RAS blockade in failing hearts.

  3. Cardiac resynchronization induces major structural and functional reverse remodeling in patients with New York Heart Association class I/II heart failure

    DEFF Research Database (Denmark)

    St John Sutton, Martin; Ghio, Stefano; Plappert, Ted;

    2009-01-01

    BACKGROUND: Cardiac resynchronization therapy (CRT) improves LV structure, function, and clinical outcomes in New York Heart Association class III/IV heart failure with prolonged QRS. It is not known whether patients with New York Heart Association class I/II systolic heart failure exhibit left...... ventricular (LV) reverse remodeling with CRT or whether reverse remodeling is modified by the cause of heart failure. METHODS AND RESULTS: Six hundred ten patients with New York Heart Association class I/II heart failure, QRS duration > or =120 ms, LV end-diastolic dimension > or =55 mm, and LV ejection...... reduction in LV end-diastolic and end-systolic volume indexes and a 3-fold greater increase in LV ejection fraction in patients with nonischemic causes of heart failure. CONCLUSIONS: CRT in patients with New York Heart Association I/II resulted in major structural and functional reverse remodeling at 1 year...

  4. Long Non-Coding RNA Malat-1 Is Dispensable during Pressure Overload-Induced Cardiac Remodeling and Failure in Mice.

    Directory of Open Access Journals (Sweden)

    Tim Peters

    Full Text Available Long non-coding RNAs (lncRNAs are a class of RNA molecules with diverse regulatory functions during embryonic development, normal life, and disease in higher organisms. However, research on the role of lncRNAs in cardiovascular diseases and in particular heart failure is still in its infancy. The exceptionally well conserved nuclear lncRNA Metastasis associated in lung adenocarcinoma transcript 1 (Malat-1 is a regulator of mRNA splicing and highly expressed in the heart. Malat-1 modulates hypoxia-induced vessel growth, activates ERK/MAPK signaling, and scavenges the anti-hypertrophic microRNA-133. We therefore hypothesized that Malat-1 may act as regulator of cardiac hypertrophy and failure during cardiac pressure overload induced by thoracic aortic constriction (TAC in mice.Absence of Malat-1 did not affect cardiac hypertrophy upon pressure overload: Heart weight to tibia length ratio significantly increased in WT mice (sham: 5.78±0.55, TAC 9.79±1.82 g/mm; p<0.001 but to a similar extend also in Malat-1 knockout (KO mice (sham: 6.21±1.12, TAC 8.91±1.74 g/mm; p<0.01 with no significant difference between genotypes. As expected, TAC significantly reduced left ventricular fractional shortening in WT (sham: 38.81±6.53%, TAC: 23.14±11.99%; p<0.01 but to a comparable degree also in KO mice (sham: 37.01±4.19%, TAC: 25.98±9.75%; p<0.05. Histological hallmarks of myocardial remodeling, such as cardiomyocyte hypertrophy, increased interstitial fibrosis, reduced capillary density, and immune cell infiltration, did not differ significantly between WT and KO mice after TAC. In line, the absence of Malat-1 did not significantly affect angiotensin II-induced cardiac hypertrophy, dysfunction, and overall remodeling. Above that, pressure overload by TAC significantly induced mRNA levels of the hypertrophy marker genes Nppa, Nppb and Acta1, to a similar extend in both genotypes. Alternative splicing of Ndrg2 after TAC was apparent in WT (isoform ratio

  5. High-fat Diet Promotes Cardiac Remodeling in an Experimental Model of Obesity

    Directory of Open Access Journals (Sweden)

    Fernando Martins

    2015-01-01

    Full Text Available AbstractBackground:Although nutritional, metabolic and cardiovascular abnormalities are commonly seen in experimental studies of obesity, it is uncertain whether these effects result from the treatment or from body adiposity.Objective:To evaluate the influence of treatment and body composition on metabolic and cardiovascular aspects in rats receiving high saturated fat diet.Methods:Sixteen Wistar rats were used, distributed into two groups, the control (C group, treated with isocaloric diet (2.93 kcal/g and an obese (OB group, treated with high-fat diet (3.64 kcal/g. The study period was 20 weeks. Analyses of nutritional behavior, body composition, glycemia, cholesterolemia, lipemia, systolic arterial pressure, echocardiography, and cardiac histology were performed.Results:High-fat diet associates with manifestations of obesity, accompanied by changes in glycemia, cardiomyocyte hypertrophy, and myocardial interstitial fibrosis. After adjusting for adiposity, the metabolic effects were normalized, whereas differences in morphometric changes between groups were maintained.Conclusion:It was concluded that adiposity body composition has a stronger association with metabolic disturbances in obese rodents, whereas the high-fat dietary intervention is found to be more related to cardiac morphological changes in experimental models of diet-induced obesity.

  6. Getting to the heart of cardiac remodeling; how collagen subtypes may contribute to phenotype.

    Science.gov (United States)

    Collier, P; Watson, C J; van Es, M H; Phelan, D; McGorrian, C; Tolan, M; Ledwidge, M T; McDonald, K M; Baugh, J A

    2012-01-01

    The objective of this study was to investigate the nature and biomechanical properties of collagen fibers within the human myocardium. Targeting cardiac interstitial abnormalities will likely become a major focus of future preventative strategies with regard to the management of cardiac dysfunction. Current knowledge regarding the component structures of myocardial collagen networks is limited, further delineation of which will require application of more innovative technologies. We applied a novel methodology involving combined confocal laser scanning and atomic force microscopy to investigate myocardial collagen within ex-vivo right atrial tissue from 10 patients undergoing elective coronary bypass surgery. Immuno-fluorescent co-staining revealed discrete collagen I and III fibers. During single fiber deformation, overall median values of stiffness recorded in collagen III were 37±16% lower than in collagen I [pretraction, collagen I exhibited greater degrees of elastic recoil [patrial biopsies taken from patients in permanent atrial fibrillation (n=5) versus sinus rhythm (n=5), stiffness of both collagen fiber subtypes was augmented (patrial fibrillation compared to those in sinus rhythm are consistent with recent published findings of increased collagen cross-linking in this setting.

  7. Electrical Pacing of Cardiac Tissue Including Potassium Inward Rectification.

    Science.gov (United States)

    Galappaththige, Suran; Roth, Bradley J

    2015-01-01

    In this study cardiac tissue is stimulated electrically through a small unipolar electrode. Numerical simulations predict that around an electrode are adjacent regions of depolarization and hyperpolarization. Experiments have shown that during pacing of resting cardiac tissue the hyperpolarization is often inhibited. Our goal is to determine if the inward rectifying potassium current (IK1) causes the inhibition of hyperpolarization. Numerical simulations were carried out using the bidomain model with potassium dynamics specified to be inward rectifying. In the simulations, adjacent regions of depolarization and hyperpolarization were observed surrounding the electrode. For cathodal currents the virtual anode produces a hyperpolarization that decreases over time. For long duration pulses the current-voltage curve is non-linear, with very small hyperpolarization compared to depolarization. For short pulses, the hyperpolarization is more prominent. Without the inward potassium rectification, the current voltage curve is linear and the hyperpolarization is evident for both long and short pulses. In conclusion, the inward rectification of the potassium current explains the inhibition of hyperpolarization for long duration stimulus pulses, but not for short duration pulses.

  8. Electrical Pacing of Cardiac Tissue Including Potassium Inward Rectification.

    Directory of Open Access Journals (Sweden)

    Suran Galappaththige

    Full Text Available In this study cardiac tissue is stimulated electrically through a small unipolar electrode. Numerical simulations predict that around an electrode are adjacent regions of depolarization and hyperpolarization. Experiments have shown that during pacing of resting cardiac tissue the hyperpolarization is often inhibited. Our goal is to determine if the inward rectifying potassium current (IK1 causes the inhibition of hyperpolarization. Numerical simulations were carried out using the bidomain model with potassium dynamics specified to be inward rectifying. In the simulations, adjacent regions of depolarization and hyperpolarization were observed surrounding the electrode. For cathodal currents the virtual anode produces a hyperpolarization that decreases over time. For long duration pulses the current-voltage curve is non-linear, with very small hyperpolarization compared to depolarization. For short pulses, the hyperpolarization is more prominent. Without the inward potassium rectification, the current voltage curve is linear and the hyperpolarization is evident for both long and short pulses. In conclusion, the inward rectification of the potassium current explains the inhibition of hyperpolarization for long duration stimulus pulses, but not for short duration pulses.

  9. Cardiac thrombus developing after an accidental high-voltage electric shock in a child.

    Science.gov (United States)

    Akın, Alper; Bilici, Meki; Demir, Fikri; Gözü Pirinççioğlu, Ayfer; Yavuz, Celal

    2015-01-01

    Electric shock is a condition that may affect various organ systems and potentially cause death. Cardiac findings vary from asymptomatic mild injury to fatal myocardial involvement. Herein we present a five-year-old boy with a cardiac thrombus developing after an accidental electrical shock. Cardiac arrhythmias and evidence of ischemia have been reported after electric shock; we were, however, unable to identify an earlier case report of intracardiac thrombosis related to electric shock. Findings such as elevated cardiac enzymes and systolic dysfunction, which indicate myocardial damage following electric shock, were present in our patient. We think that the cardiac thrombus might have resulted from the myocardial damage and the slowed intracardiac blood flow related to systolic dysfunction. As the thrombus was thought to have been formed through known mechanisms, it was treated traditionally. However, further data regarding the etiology and management of such thrombi is needed.

  10. Relationship of cardiac arrhythmias to myocar- dial remodeling and expression of adhesion molecules in patients with mitral valve prolapse

    Directory of Open Access Journals (Sweden)

    A.V. Yagoda

    Conclusion. Myocardial remodeling and dysregulation of cell adhesion proteins are recorded in young patients with MVP and arrhythmias. Relaionship of severity of arrhythmic syndrome to myocardial remodeling and VCAM-1 level was revealed.

  11. Crosstalk between obesity and MMP-9 in cardiac remodelling -a cross-sectional study in apparent treatment-resistant hypertension.

    Science.gov (United States)

    Ritter, Alessandra Mileni Versuti; de Faria, Ana Paula; Barbaro, Natália; Sabbatini, Andréa Rodrigues; Corrêa, Nathália Batista; Brunelli, Veridiana; Amorim, Rivadavio; Modolo, Rodrigo; Moreno, Heitor

    2017-04-01

    The balance between matrix metalloproteinases (MMP) and their tissue inhibitors (TIMP) plays a key role in the development of hypertension and obesity. We aimed to evaluate the levels of MMP-2 and 9 and TIMP-2 and -1 in obese and non-obese apparent treatment-resistant hypertensive subjects (aTRH) and its association with cardiac hypertrophy. This cross-sectional study enrolled 122 subjects and divided into obese aTRH (n = 67) and non-obese (n = 55) group. Clinical and biochemical data were compared between both groups, including office BP, ambulatory BP, plasma MMP-2 and 9, TIMP-2 and 1 and left ventricular mass index (LVMI). We found higher MMP-9 levels and MMP-9/TIMP-1 ratio in obese aTRH subjects but no difference in MMP-2 and TIMP-1 levels. Obesity influenced MMP-9 levels [β = 20.8 SE =8.6, p = 0.02) independently of potential confounders. In addition, we found a positive correlation between MMP-9 and anthropomorphic parameters. Finally, obese aTRH subjects with left ventricular hypertrophy (LVH) had greater MMP-9 levels compared with non-obese with LVH. Our study suggests that MMP-9 levels are influenced by obesity and may directly participate in the progressive LV remodelling process, suggesting a possible role for a higher cardiovascular risk in apparent resistant hypertensive subjects.

  12. Structural and electrical myocardial remodeling in a rodent model of depression

    NARCIS (Netherlands)

    Carnevali, Luca; Trombini, Mimosa; Rossi, Stefano; Graiani, Gallia; Manghi, Massimo; Koolhaas, Jaap M.; Quaini, Federico; Macchi, Emilio; Nalivaiko, Eugene; Sgoifo, Andrea

    2013-01-01

    Objective: Despite a well-documented association between stress and depression with cardiac morbidity and mortality, there is no satisfactory explanation for the mechanisms linking affective and cardiac disorders. This study investigated cardiac electrophysiological properties in an animal model of

  13. Atrial metabolism and tissue perfusion as determinants of electrical and structural remodelling in atrial fibrillation.

    Science.gov (United States)

    Opacic, Dragan; van Bragt, Kelly A; Nasrallah, Hussein M; Schotten, Ulrich; Verheule, Sander

    2016-04-01

    Atrial fibrillation (AF) is the most common tachyarrhythmia in clinical practice. Over decades of research, a vast amount of knowledge has been gathered about the causes and consequences of AF related to cellular electrophysiology and features of the tissue structure that influence the propagation of fibrillation waves. Far less is known about the role of myocyte metabolism and tissue perfusion in the pathogenesis of AF. However, the rapid rates of electrical activity and contraction during AF must present an enormous challenge to the energy balance of atrial myocytes. This challenge can be met by scaling back energy demand and by increasing energy supply, and there are several indications that both phenomena occur as a result of AF. Still, there is ample evidence that these adaptations fall short of redressing this imbalance, which may represent a driving force for atrial electrical as well as structural remodelling. In addition, several 'metabolic diseases' such as diabetes, obesity, and abnormal thyroid function precipitate some well-known 'culprits' of the AF substrate such as myocyte hypertrophy and fibrosis, while some other AF risk factors, such as heart failure, affect atrial metabolism. This review provides an overview of metabolic and vascular alterations in AF and their involvement in its pathogenesis.

  14. Inhibiting metalloproteases with PD 166793 in heart failure: impact on cardiac remodeling and beyond.

    Science.gov (United States)

    Kaludercic, Nina; Lindsey, Merry L; Tavazzi, Barbara; Lazzarino, Giuseppe; Paolocci, Nazareno

    2008-01-01

    Metalloproteinases (MMPs, also called matrixins) are extracellular proteolytic enzymes involved in the degradation of both matrix and nonmatrix proteins. Currently, 25 MMPs have been identified in humans, and the overexpression of one or more MMPs has been implicated in several pathologies, spanning from cancer to rheumathoid arthritis to cardiovascular disease. While research over the past 20 years has focused on understanding MMP biology and selectively inhibiting MMP activity, key issues that remain to be addressed include MMP roles in the context of normal versus pathological conditions and whether globally inhibiting MMPs improves or deteriorates overall organ function. In terms of cardiovascular disease, increased MMP expression has been demonstrated in the setting of myocardial ischemia, reperfusion injury, and during the progression to congestive heart failure. MMPs are also major contributors to the progression of atherosclerotic lesions. In this review, we focus on cardiovascular effects produced by PD 166793, a wide-broad spectrum MMP inhibitor, originally developed by Parke-Davis (now Pfizer). We will briefly review its structure, mechanism of action, and inhibitory capacity. Finally, we will illustrate the cardiac contexts, both in vivo and in vitro, in which PD166793 administration has proven beneficial.

  15. Cardiac-Restricted IGF-1Ea Overexpression Reduces the Early Accumulation of Inflammatory Myeloid Cells and Mediates Expression of Extracellular Matrix Remodelling Genes after Myocardial Infarction

    Directory of Open Access Journals (Sweden)

    Enrique Gallego-Colon

    2015-01-01

    Full Text Available Strategies to limit damage and improve repair after myocardial infarct remain a major therapeutic goal in cardiology. Our previous studies have shown that constitutive expression of a locally acting insulin-like growth factor-1 Ea (IGF-1Ea propeptide promotes functional restoration after cardiac injury associated with decreased scar formation. In the current study, we investigated the underlying molecular and cellular mechanisms behind the enhanced functional recovery. We observed improved cardiac function in mice overexpressing cardiac-specific IGF-1Ea as early as day 7 after myocardial infarction. Analysis of gene transcription revealed that supplemental IGF-1Ea regulated expression of key metalloproteinases (MMP-2 and MMP-9, their inhibitors (TIMP-1 and TIMP-2, and collagen types (Col 1α1 and Col 1α3 in the first week after injury. Infiltration of inflammatory cells, which direct the remodelling process, was also altered; in particular there was a notable reduction in inflammatory Ly6C+ monocytes at day 3 and an increase in anti-inflammatory CD206+ macrophages at day 7. Taken together, these results indicate that the IGF-1Ea transgene shifts the balance of innate immune cell populations early after infarction, favouring a reduction in inflammatory myeloid cells. This correlates with reduced extracellular matrix remodelling and changes in collagen composition that may confer enhanced scar elasticity and improved cardiac function.

  16. Ablation of C/EBP homologous protein increases the acute phase mortality and doesn't attenuate cardiac remodeling in mice with myocardial infarction.

    Science.gov (United States)

    Luo, Guangjin; Li, Qingman; Zhang, Xiajun; Shen, Liang; Xie, Jiahe; Zhang, Jingwen; Kitakaze, Masafumi; Huang, Xiaobo; Liao, Yulin

    2015-08-14

    Endoplasmic reticulum stress is a proapoptotic and profibrotic stimulus. Ablation of C/EBP homologous protein (CHOP) is reported to reverse cardiac dysfunction by attenuating cardiac endoplasmic reticulum stress in mice with pressure overload or ischemia/reperfusion, but it is unclear whether loss of CHOP also inhibits cardiac remodeling induced by permanent-infarction. In mice with permanent ligation of left coronary artery, we found that ablation of CHOP increased the acute phase mortality. For the mice survived to 4 weeks, left ventricular anterior (LV) wall thickness was larger in CHOP knockout mice than in the wildtype littermates, while no difference was noted on posterior wall thickness, LV dimensions, LV fractional shortening and ejection fraction. Similarly, invasive assessment of LV hemodynamics, morphological analysis of heart and lung weight indexes, myocardial fibrosis and TUNEL-assessed apoptosis showed no significant differences between CHOP knockout mice and their wildtype ones, while in mice with ischemia for 45 min and reperfusion for 1 week, myocardial fibrosis and apoptosis in the infarct area were significantly attenuated in CHOP knockout mice. These findings indicate that ablation of CHOP doesn't ameliorate cardiac remodeling induced by permanent-myocardial infarction, which implicates that early reperfusion is a prerequisite for ischemic myocardium to benefit from CHOP inhibition.

  17. Effect of transcutaneous electric stimulation on the cardiac electrical activity in New Zealand white rabbits

    Directory of Open Access Journals (Sweden)

    Wang ZHANG

    2015-10-01

    Full Text Available Objective To study the effect of transcutaneous electric stimulation on the cardiac electrical activity in New Zealand white rabbits, in order to search a safety threshold for clinical electrical stimulation therapy, as to provide the theoretical basis for the design of in vitro pacemaker. Methods New Zealand white rabbits were randomly assigned into 17 groups (6 each. Rabbits in 16 experimental groups were given 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75 and 80V electrical stimulation, respectively, with the stimulating site designated at epigastric region. BL -420F biological function experimental system was employed to supply the power and acquire the ECG, with the output pulse electrical stimulation frequency set at 270 times/minute, and the stimulating wave as square wave. A control group was set, in which the stimulating voltage was set to 35V, the stimulant anode was located in the anterior chest area, and the cathode was on the skin surface of back corresponding to the site of the heart, and the rest was the same as in experimental groups. Results No stimulation rhythm was observed in rabbits of those experimental groups with voltage ≤35V, but all stimulation rhythm was observed in rabbits of control group. No arrhythmia occurred in rabbits of those experimental groups with voltage ≤30V, while the heart rate was slowed down after stimulation in rabbits of the experimental groups with voltage ≥45V stimulation. In rabbits receiving stimulation with voltage ≤35V there was no dystropy or light dystropy, but with no visible injury to the local tissues. No visible injury was observed in the rabbits undergoing stimulation with voltage ≤40V. Conclusion Pulse electric stimulation with voltage ≤35V in the epigastric region would not affect the cardiac electrical activity in rabbits, while stimulation with 35V will lead to all pacing rhythm of the heart without affecting the cardiac electrical activity in rabbits

  18. Research Progress of ACE2 against Cardiac Remodeling%ACE2抗心室重构作用的研究进展

    Institute of Scientific and Technical Information of China (English)

    张培勇

    2013-01-01

    心室重构是心脏对损伤或室壁压力增高的适应性变化,病理性心室重构导致心功能进行性恶化,最终导致心力衰竭.肾素-血管紧张素系统(RAS)通过间接和直接作用在心室重构的发生、发展中发挥重要作用.血管紧张素转换酶2(ACE2)可水解血管紧张素Ⅱ生成血管紧张素-(1-7),负性调节RAS,延缓或逆转病理型心室重构.现对近年来ACE2抗心室重构作用的研究进展进行综述.%Remodeling of the heart which occurs in response to injury and/or an increase in wall stress plays a key role in the progressive deterioration of cardiac function that leads to heart failure. The renin-angiotensin system ( RAS ) is a key regulator in the progress of pathological remodeling, through indirect and direct effects on cells of heart. Angiotensin converting enzyme 2( ACE2 ), which can break down Ang Ⅱ while generating angiotensin-( 1 -7 ), can down-regulate RAS and have an important role against cardiac remodeling. Here is to make a review focusing on advances made in understanding the effects of ACE2 against cardiac remodeling.

  19. Nanowires and Electrical Stimulation Synergistically Improve Functions of hiPSC Cardiac Spheroids.

    Science.gov (United States)

    Richards, Dylan J; Tan, Yu; Coyle, Robert; Li, Yang; Xu, Ruoyu; Yeung, Nelson; Parker, Arran; Menick, Donald R; Tian, Bozhi; Mei, Ying

    2016-07-13

    The advancement of human induced pluripotent stem-cell-derived cardiomyocyte (hiPSC-CM) technology has shown promising potential to provide a patient-specific, regenerative cell therapy strategy to treat cardiovascular disease. Despite the progress, the unspecific, underdeveloped phenotype of hiPSC-CMs has shown arrhythmogenic risk and limited functional improvements after transplantation. To address this, tissue engineering strategies have utilized both exogenous and endogenous stimuli to accelerate the development of hiPSC-CMs. Exogenous electrical stimulation provides a biomimetic pacemaker-like stimuli that has been shown to advance the electrical properties of tissue engineered cardiac constructs. Recently, we demonstrated that the incorporation of electrically conductive silicon nanowires to hiPSC cardiac spheroids led to advanced structural and functional development of hiPSC-CMs by improving the endogenous electrical microenvironment. Here, we reasoned that the enhanced endogenous electrical microenvironment of nanowired hiPSC cardiac spheroids would synergize with exogenous electrical stimulation to further advance the functional development of nanowired hiPSC cardiac spheroids. For the first time, we report that the combination of nanowires and electrical stimulation enhanced cell-cell junction formation, improved development of contractile machinery, and led to a significant decrease in the spontaneous beat rate of hiPSC cardiac spheroids. The advancements made here address critical challenges for the use of hiPSC-CMs in cardiac developmental and translational research and provide an advanced cell delivery vehicle for the next generation of cardiac repair.

  20. Adaptations to iron deficiency: cardiac functional responsiveness to norepinephrine, arterial remodeling, and the effect of beta-blockade on cardiac hypertrophy

    Directory of Open Access Journals (Sweden)

    Walker LeeAnn

    2002-01-01

    Full Text Available Abstract Background Iron deficiency (ID results in ventricular hypertrophy, believed to involve sympathetic stimulation. We hypothesized that with ID 1 intravenous norepinephrine would alter heart rate (HR and contractility, 2 abdominal aorta would be larger and more distensible, and 3 the beta-blocker propanolol would reduce hypertrophy. Methods 1 30 CD rats were fed an ID or replete diet for 1 week or 1 month. Norepinephrine was infused via jugular vein; pressure was monitored at carotid artery. Saline infusions were used as a control. The pressure trace was analyzed for HR, contractility, systolic and diastolic pressures. 2 Abdominal aorta catheters inflated the aorta, while digital microscopic images were recorded at stepwise pressures to measure arterial diameter and distensibility. 3 An additional 10 rats (5 ID, 5 control were given a daily injection of propanolol or saline. After 1 month, the hearts were excised and weighed. Results Enhanced contractility, but not HR, was associated with ID hypertrophic hearts. Systolic and diastolic blood pressures were consistent with an increase in arterial diameter associated with ID. Aortic diameter at 100 mmHg and distensibility were increased with ID. Propanolol was associated with an increase in heart to body mass ratio. Conclusions ID cardiac hypertrophy results in an increased inotropic, but not chronotropic response to the sympathetic neurotransmitter, norepinephrine. Increased aortic diameter is consistent with a flow-dependent vascular remodeling; increased distensibility may reflect decreased vascular collagen content. The failure of propanolol to prevent hypertrophy suggests that ID hypertrophy is not mediated via beta-adrenergic neurotransmission.

  1. The Nuclear Factor kappaB Inhibitor Pyrrolidine Dithiocarbamate Prevents Cardiac Remodelling and Matrix Metalloproteinase-2 Up-Regulation in Renovascular Hypertension.

    Science.gov (United States)

    Cau, Stefany B A; Guimaraes, Danielle A; Rizzi, Elen; Ceron, Carla S; Gerlach, Raquel F; Tanus-Santos, Jose E

    2015-10-01

    Imbalanced matrix metalloproteinase (MMP) activity is involved in hypertensive cardiac hypertrophy. Pharmacological inhibition of nuclear factor kappaB (NF-кB) with pyrrolidine dithiocarbamate (PDTC) can prevent MMP up-regulation. We suggested that treatment with PDTC could prevent 2-kidney, 1-clip (2K1C) hypertension-induced left ventricular remodelling. Sham-operated controls or 2K1C rats with hypertension received either vehicle or PDTC (100 mg/kg/day) by gavage for 8 weeks. Systolic blood pressure was monitored every week. Histological assessment of left ventricles was carried out with haematoxylin/eosin sections, and fibrosis was quantified in picrosirius red-stained sections. Oxidative stress was evaluated in heart samples with the dihydroethidium probe. Cardiac MMP activity was determined by in situ zymography, and cardiac MMP-2 was assessed by immunofluorescence. 2K1C surgery significantly increased systolic blood pressure in the 2K1C vehicle. PDTC exerted antihypertensive effects after 2 weeks of treatment. Histology revealed increased left ventricular and septum wall thickness associated with augmented myocyte diameter in hypertensive rats, which were reversed by treatment with PDTC. Hypertensive rats developed pronounced cardiac fibrosis with increased interstitial collagen area, increased cardiac reactive oxygen species levels, gelatinase activity and MMP-2 expression. PDTC treatment decreased these alterations. These findings show that PDTC modulates myocardial MMP-2 expression and ameliorates cardiac remodelling in renovascular hypertension. These results suggest that interfering with MMP expression at transcriptional level may be an interesting strategy in the therapy of organ damage associated with hypertension.

  2. Electrical stimulation of cardiac adipose tissue-derived progenitor cells modulates cell phenotype and genetic machinery.

    Science.gov (United States)

    Llucià-Valldeperas, A; Sanchez, B; Soler-Botija, C; Gálvez-Montón, C; Prat-Vidal, C; Roura, S; Rosell-Ferrer, J; Bragos, R; Bayes-Genis, A

    2015-11-01

    A major challenge of cardiac tissue engineering is directing cells to establish the physiological structure and function of the myocardium being replaced. Our aim was to examine the effect of electrical stimulation on the cardiodifferentiation potential of cardiac adipose tissue-derived progenitor cells (cardiac ATDPCs). Three different electrical stimulation protocols were tested; the selected protocol consisted of 2 ms monophasic square-wave pulses of 50 mV/cm at 1 Hz over 14 days. Cardiac and subcutaneous ATDPCs were grown on biocompatible patterned surfaces. Cardiomyogenic differentiation was examined by real-time PCR and immunocytofluorescence. In cardiac ATDPCs, MEF2A and GATA-4 were significantly upregulated at day 14 after stimulation, while subcutaneous ATDPCs only exhibited increased Cx43 expression. In response to electrical stimulation, cardiac ATDPCs elongated, and both cardiac and subcutaneous ATDPCs became aligned following the linear surface pattern of the construct. Cardiac ATDPC length increased by 11.3%, while subcutaneous ATDPC length diminished by 11.2% (p = 0.013 and p = 0.030 vs unstimulated controls, respectively). Compared to controls, electrostimulated cells became aligned better to the patterned surfaces when the pattern was perpendicular to the electric field (89.71 ± 28.47º for cardiac ATDPCs and 92.15 ± 15.21º for subcutaneous ATDPCs). Electrical stimulation of cardiac ATDPCs caused changes in cell phenotype and genetic machinery, making them more suitable for cardiac regeneration approaches. Thus, it seems advisable to use electrical cell training before delivery as a cell suspension or within engineered tissue.

  3. The Combined Effect of Endurance Training and Various Doses of Atorvastatin on Cardiac Remodeling after Myocardial Infarction in Male Rats

    Directory of Open Access Journals (Sweden)

    Hadi Abdi

    2015-12-01

    Full Text Available Introduction: Statins and exercise have beneficial effects in preventing cardiovascular diseases. However, prolonged use of statins particularly at high doses has unpleasant side effects. This study aimed to investigate the combined effect of endurance training and three doses of Atorvastatin on cardiac remodeling after myocardial infarction in male rats.Methods: 75 male wistar rats (weighing 210-250g were randomly divided to 9 groups. Sham, control, endurance training, Atorvastatin (5, 10 and 15 mg/kg, and exercise plus Atorvastatin (5, 10 and 15 mg/kg: Myocardial infarction was induced by subcutaneous injection of isoprenaline (150 mg/kg in two consecutive days. Drug and training intervention was initiated 2 days after infarction and continued for 4 weeks. In order to assess the necrosis lesion and fibrosis tissue, hematoxylin & eosin and masson trichrome staining were used respectively.Results: The combination of endurance training and various doses of Atorvastatin significantly reduced the amount of necrosis and fibrosis tissue compared with the control group (P<0.01. Endurance exercise training alone did not cause significant changes in the extent of necrosis damage, but significantly increased fibrosis tissue compared with the control group (P<0.001. Various doses of Atorvastatin alone significantly reduced necrosis damage (P<0.001, but the difference between these groups and the control group in terms of fibrous tissue was statistically significant only at dose of 15 mg/kg (P<0.001.Conclusion: The results of this study showed that the combination of training and various doses of Atorvastatin are more effective in improving of tissue damage caused by myocardial infarction than exercise and Atorvastatin alone. However, the use of endurance training with medical therapy can not reduce the dose of Atorvastatin.

  4. Sensing Cardiac Electrical Activity With a Cardiac Myocyte--Targeted Optogenetic Voltage Indicator

    NARCIS (Netherlands)

    Chang Liao, Mei-Ling; de Boer, Teun P; Mutoh, Hiroki; Raad, Nour; Richter, Claudia; Wagner, Eva; Downie, Bryan R; Unsöld, Bernhard; Arooj, Iqra; Streckfuss-Bömeke, Katrin; Döker, Stephan; Luther, Stefan; Guan, Kaomei; Wagner, Stefan; Lehnart, Stephan E; Maier, Lars S; Stühmer, Walter; Wettwer, Erich; van Veen, Toon; Morlock, Michael M; Knöpfel, Thomas; Zimmermann, Wolfram-Hubertus

    2015-01-01

    RATIONALE: Monitoring and controlling cardiac myocyte activity with optogenetic tools offer exciting possibilities for fundamental and translational cardiovascular research. Genetically encoded voltage indicators may be particularly attractive for minimal invasive and repeated assessments of cardiac

  5. Effect of nifekalant on acute electrical remodelling in rapid atrial pacing canine model

    Institute of Scientific and Technical Information of China (English)

    TANG Min; ZHANG Shu; SUN Qi; HUA Wei; HUANG Cong-xin

    2006-01-01

    inhibited ERP shortening and ERP heterogeneity increasing,decreased AF induction. Nifekalant can reverse acute electrical remodeling effect in this model.

  6. Effects of Long-term Ramipril on Ventricular Remodeling, Cardiac Function and Survival in Rat Congestive Heart Failure after Myocardial Infarction

    Institute of Scientific and Technical Information of China (English)

    陶则伟; 黄元伟

    2004-01-01

    Objectives The purpose of this study was to investigate the effects of long-term ramipril on ventricular remodeling, cardiac function and survival in rat congestive heart failure after myocardial infarction. Methods Myocardial infarction (MI) was caused by ligation of the left anterior descending coronary artery in rats. 7 days after the surgery, the surviving rats were randomly assigned to the following treatment protocols: 1) MI rats with no therapy, 2) MI rats treated with ramipril 3 mg/kg per day, 3) Sham-operated control rats, and 4) Sham-operated rats treated with ramipril 3 mg/kg per day. At 22 weeks, cardiac hemodynamic parameters such as MAP, LVSP, ±dP/dtmax and LVEDP were measured,and cardiac morphometric parameters such as HW,LVW and LVCA were measured, mRNA of cardiacmolecule genes, such as βMHC, BNP, collagen Ⅰ and Ⅲ, and TGF-β1, were quantified, and survival rates were calculated. Results Compared with sham-operated rats, MI rats without therapy showed significant increases in cardiac morphological parameters as well as in mRAN expressions of cardiac molecule genes (P<0.01); while their hemodynamic parameters were significantly impaired (P<0.01), and survival rate shortened (P<0.05). Compared with MI rats with no therapy, MI rats treated with ramipril showed significant attenuation of mRAN expressions of cardiac molecule genes (P<0.01); while their hemodynamic parameters were significantly impaired (P<0.01), and survival rate shortened (P<0.05). Compared with MI rats with no therapy, MI rats treated with ramipril showed significant attenuation of mRAN expressions of cardiac molecule genes (P<0.01); while their hemodynamic parameters were significantly improved (P<0.05 or P<0.01), and survival rates prolonged (P<0.05). Conclusions Treatment with long-term ramipril may improve LV remodeling, cardiac function and survival in rat congestive heart failure after MI.

  7. Impact of pulmonary vein isolation on atrial vagal activity and atrial electrical remodeling

    Institute of Scientific and Technical Information of China (English)

    Yingxue Dong; Shulong Zhang; Lianjun Gao; Hongwei Zhao; Donghui Yang; Yunlong Xia; Yanzong Yang

    2008-01-01

    Objective Mechanisms of pulmonary vein isolation (PVI) for atrial fibrillation remain controversy.This study aimed to investigate the impact of PVI on vagal modulation to atria.Methods Eighteen adult mongrel dogs under general anesthesia were randomly divided into two groups.Bilateral cervical sympathovagal trunks were decentralized and sympathetic effects was blocked by metoprolol administration.Atrial electrical remodeling (AER) was established by rapid right atrial pacing at the rate of 600 bpm for 30 minutes.PVI was performed in group A.Atrial effective refractory period (ERP),vulnerability window (VW) of atrial fibrillation,and sinus rhythm cycle length (SCL) were measured at baseline and during vagal stimulation before and after atrial rapid pacing with and without PVI at fight atrial appendage (RAA),left atrial appendage (LAA),distal coronary sinus (CSd) and proximal coronary sinus (CSp).Results (1) Effects of PVI on vagal modulation:Shortening of SCL during vagal stimulation decreased significantly after PVI compared with that before PVI in group A (P<0.001).Shortening of ERP during vagal stimulation decreaseed significantly after PVI compared with that before PVI (P<0.05).VW of atrial fibrillation during vagal stimulation decreased significantly after PVI compared with that before PVI (P<0.05).(2) Effects of PVI on AER:shortening of ERP before and after atrial rapid pacing increased significantly at baseline and vagal stimulation in group B compared with that in group A (P<0.05).VW during vagal stimulation increased significantly after atrial rapid pacing in group B (P<0.05).Conclusion PVI attenuates the vagal modulation to the atria,thereby decreases the susceptibility to atrial fibrillation mediated by vagal activity.PVI releases AER,which maybe contributes to the vagal denervation.Our study indicates that PVI not only can eradicate triggered foci but also modify substrates for AF.(J Geriatr Cardiol 2008;5:28-32)

  8. Understanding cardiac electrical phenotypes in the genomic era

    NARCIS (Netherlands)

    A. Milano

    2015-01-01

    Sudden cardiac death (SCD) is defined as unexpected death due to a cardiac cause. It most often results from life-threatening ventricular fibrillation (VF) and ranks among the most common causes of death worldwide, with an incidence in the community varying between 0.6 and >1.4 per 1,000 individuals

  9. Proarrhythmic electrical remodelling is associated with increased beat-to-beat variability of repolarisation

    DEFF Research Database (Denmark)

    Thomsen, Morten Bækgaard; Oros, Avram; Schoenmakers, Marieke;

    2007-01-01

    Acquired long-QT syndrome in combination with increased beat-to-beat variability of repolarisation duration (BVR) is associated with lethal torsades de pointes arrhythmias (TdP) in dogs with remodelled heart after atrioventricular block (AVB). We evaluated the relative contributions of bradycardi...... and ventricular remodelling to proarrhythmic BVR with and without pharmacological I(Kr) block in order to identify the individual at risk....

  10. HCM-Linked Δ 160E Cardiac Troponin T Mutation Causes Unique Progressive Structural and Molecular Ventricular Remodeling in Transgenic Mice

    Science.gov (United States)

    Moore, Rachel K.; Grinspan, Lauren Tal; Jimenez, Jesus; Guinto, Pia J.; Ertz-Berger, Briar; Tardiff, Jil C.

    2013-01-01

    Hypertrophic cardiomyopathy (HCM) is a primary disease of cardiac muscle, and one of the most common causes of sudden cardiac death (SCD) in young people. Many mutations in cardiac troponin T (cTnT) lead to a complex form of HCM with varying degrees of ventricular hypertrophy and ~65% of all cTnT mutations occur within or flanking the elongated N-terminal TNT1 domain. Biophysical studies have predicted that distal TNT1 mutations, including Δ160E, cause disease by a novel, yet unknown mechanism as compared to N-terminal mutations. To begin to address the specific effects of this commonly observed cTnT mutation we generated two independent transgenic mouse lines carrying variant doses of the mutant transgene. Hearts from the 30% and 70% cTnT Δ160E lines demonstrated a highly unique, dose-dependent disruption in cellular and sarcomeric architecture and a highly progressive pattern of ventricular remodeling. While adult ventricular myocytes isolated from Δ160E transgenic mice exhibited dosage-independent mechanical impairments, decreased sarcoplasmic reticulum calcium load and SERCA2a calcium uptake activity, the observed decreases in calcium transients were dosage-dependent. The latter findings were concordant with measures of calcium regulatory proteins abundance and phosphorylation state. Finally, studies of whole heart physiology in the isovolumic mode demonstrated dose-dependent differences in the degree of cardiac dysfuction. We conclude that the observed clinical severity of the cTnT Δ160E mutation is caused by a combination of direct sarcomeric disruption coupled to a profound disregulation of Ca2+ homeostasis at the cellular level that results in a unique and highly progressive pattern of ventricular remodeling. PMID:23434821

  11. Three dimensional graphene scaffold for cardiac tissue engineering and in-situ electrical recording.

    Science.gov (United States)

    Ameri, S K; Singh, P K; D'Angelo, R; Stoppel, W; Black, L; Sonkusale, S R

    2016-08-01

    In this paper, we present a three-dimensional graphene foam made of few layers of CVD grown graphene as a scaffold for growing cardiac cells and recording their electrical activity. Our results show that graphene foam not only provides an excellent extra-cellular matrix (ECM) for the culture of such electrogenic cells but also enables recording of its extracellular electrical activity in-situ. Recording is possible due to graphene's excellent conductivity. In this paper, we present our results on the fabrication of the graphene scaffold and initial studies on the culture of cardiac cell lines such as HL-1 and recording of their real-time electrical activity.

  12. Modulation of vagal activity to atria electrical remodeling resulted from rapid atrial pacing

    Institute of Scientific and Technical Information of China (English)

    Shulong Zhang; Yanzong Yang; Yingxue Dong; Lianjun Gao; Donghui Yang; Chunyue Zhao; Hongwei Zhao; Xiaomeng Yin; Jinqiu Liu; Zhihu Lin

    2008-01-01

    Background Atrial electrical remodeling(AER)plays an important role in the pathogenesis and maintenance of atrialfibrillation.However,little is known about modulation of vagal activilty to AER.This study aimed to investigate the relationshipbetween vagal moduation and AER. Methods Twenty four adult mongrel dogs under general anesthesia were randomized into 3groups.Sympathetic activity was blocked by administration of metoprolol in 3 groups.The changes in vagal modulation to atria afterAER were observed in 10 dogs without vagal interruption in group A.The effects of vagal intervention on AER were investigated in 8dogs with administration of atropine in group B.The impact of aggressively vagal activity on AER was studied in 6 dogs with bilateralcervical vag sympathetic trunLks stimulation during AER in group C.Bilateral cervicall vagosympathetic trunks were decentralized.Multipolar catheters wereplaced into high right atria(RA),coronary sinus(CS)and rightventricle(RV).AER was induced by 600 bpmpacing through RA catheter for 30 minutes.Attial effective refractory period(ERP)and vulnerability window (VW)of atrial fibrillationwere measured with and without vagal stimulation before and after AER.Results In group A,ERP decreased significantly at baselineand during vagal stimulation after AER compared with that beforeAER(all P<0.05).In group B,ERP remaind unchanged at baselineand vagal stimulation after AER compared with tbat before AER (all P>0.05).In group C,ERP shortened significantly at baseline andvagal stimulation after AER compared with that before AER(all P<0.05).ERP shortening after AER in Groups A and C increasedsignificantly than that in group B (all P<0.05).Atrial fibrillation could not be induced at baseline(VW close to 0) before and after AERin three groups.VW became widen significantly during vagal stimulation after AER compared with that before AER in Groups A and C(all P<0.05),while VW remained unchanged in group B (VW close to 0).Conclusions

  13. Circulating Endothelial Cells and Endothelial Function predict Major Adverse Cardiac Events and Early Adverse Left Ventricular Remodeling in Patients with ST-Segment Elevation Myocardial Infarction

    Science.gov (United States)

    Magdy, Abdel Hamid; Bakhoum, Sameh; Sharaf, Yasser; Sabry, Dina; El-Gengehe, Ahmed T; Abdel-Latif, Ahmed

    2016-01-01

    Endothelial progenitor cells (EPCs) and circulating endothelial cells (CECs) are mobilized from the bone marrow and increase in the early phase after ST-elevation myocardial infarction (STEMI). The aim of this study was to assess the prognostic significance of CECs and indices of endothelial dysfunction in patients with STEMI. In 78 patients with acute STEMI, characterization of CD34+/VEGFR2+ CECs, and indices of endothelial damage/dysfunction such as brachial artery flow mediated dilatation (FMD) were determined. Blood samples for CECs assessment and quantification were obtained within 24 hours of admission and FMD was assessed during the index hospitalization. At 30 days follow up, the primary composite end point of major cardiac adverse events (MACE) consisting of all-cause mortality, recurrent non-fatal MI, or heart failure and the secondary endpoint of early adverse left ventricular (LV) remodeling were analyzed. The 17 patients (22%) who developed MACE had significantly higher CEC level (P = 0.004), vWF level (P =0.028), and significantly lower FMD (P = 0.006) compared to the remaining patients. Logistic regression analysis showed that CECs level and LV ejection fraction were independent predictors of MACE. The areas under the receiver operating characteristic curves (ROC) for CEC level, FMD, and the logistic model with both markers were 0.73, 0.75, and 0.82 respectively for prediction of the MACE. The 16 patients who developed the secondary endpoint had significantly higher CEC level compared to remaining patients (p =0.038). In conclusion, increased circulating endothelial cells and endothelial dysfunction predicted the occurrence of major adverse cardiac events and adverse cardiac remodeling in patients with STEMI. PMID:26864952

  14. Effects of Potassium Currents upon Action Potential of Cardiac Cells Exposed to External Electric fields

    Institute of Scientific and Technical Information of China (English)

    An-Ying Zhang; Xiao-Feng Pang

    2008-01-01

    Previous studies show that exposure to high-voltage electric fields would influence the electro cardiogram both in experimental animate and human beings. The effects of the external electric fields upon action potential of cardiac cells are studied in this paper based on the dynamical model, LR91. Fourth order Runger-Kuta is used to analyze the change of potassium ion channels exposed to external electric fields in detail. Results indicate that external electric fields could influence the current of potassium ion by adding an induced component voltage on membrane. This phenomenon might be one of the reasons of heart rate anomaly under the high-voltage electric fields.

  15. An unusual case of cardiac tamponade following electrical cardioversion

    NARCIS (Netherlands)

    Jessurun, GAJ; Crijns, HJGM; vanWijngaarden, J

    1996-01-01

    The clinical presentation of cardiac tamponade may uncover underlying pericardial disease. We describe a patient who was being treated for lone atrial fibrillation, In this case, direct current cardioversion for recurrence of atrial fibrillation was complicated by a life-threatening hemopericardium.

  16. Biphasic Electrical Field Stimulation Aids in Tissue Engineering of Multicell-Type Cardiac Organoids

    Science.gov (United States)

    Chiu, Loraine L.Y.; Iyer, Rohin K.; King, John-Paul

    2011-01-01

    The main objectives of current work were (1) to compare the effects of monophasic or biphasic electrical field stimulation on structure and function of engineered cardiac organoids based on enriched cardiomyocytes (CM) and (2) to determine if electrical field stimulation will enhance electrical excitability of cardiac organoids based on multiple cell types. Organoids resembling cardiac myofibers were cultivated in Matrigel-coated microchannels fabricated of poly(ethylene glycol)-diacrylate. We found that field stimulation using symmetric biphasic square pulses at 2.5 V/cm, 1 Hz, 1 ms (per pulse phase) was an improved stimulation protocol, as compared to no stimulation and stimulation using monophasic square pulses of identical total amplitude and duration (5 V/cm, 1 Hz, 2 ms). This was supported by the highest success rate for synchronous contractions, low excitation threshold, the highest cell density, and the highest expression of Connexin-43 in the biphasic group. Subsequently, enriched CM were seeded on the networks of (1) cardiac fibroblasts (FB), (2) D4T endothelial cells (EC), or (3) a mixture of FB and EC that were precultured for 2 days prior to the addition of enriched CM. Biphasic field stimulation was also effective at improving electrical excitability of these cardiac organoids by improving the three-dimensional organization of the cells, increasing cellular elongation and enhancing Connexin-43 presence. PMID:18783322

  17. Biphasic electrical field stimulation aids in tissue engineering of multicell-type cardiac organoids.

    Science.gov (United States)

    Chiu, Loraine L Y; Iyer, Rohin K; King, John-Paul; Radisic, Milica

    2011-06-01

    The main objectives of current work were (1) to compare the effects of monophasic or biphasic electrical field stimulation on structure and function of engineered cardiac organoids based on enriched cardiomyocytes (CM) and (2) to determine if electrical field stimulation will enhance electrical excitability of cardiac organoids based on multiple cell types. Organoids resembling cardiac myofibers were cultivated in Matrigel-coated microchannels fabricated of poly(ethylene glycol)-diacrylate. We found that field stimulation using symmetric biphasic square pulses at 2.5 V/cm, 1 Hz, 1 ms (per pulse phase) was an improved stimulation protocol, as compared to no stimulation and stimulation using monophasic square pulses of identical total amplitude and duration (5 V/cm, 1 Hz, 2 ms). This was supported by the highest success rate for synchronous contractions, low excitation threshold, the highest cell density, and the highest expression of Connexin-43 in the biphasic group. Subsequently, enriched CM were seeded on the networks of (1) cardiac fibroblasts (FB), (2) D4T endothelial cells (EC), or (3) a mixture of FB and EC that were precultured for 2 days prior to the addition of enriched CM. Biphasic field stimulation was also effective at improving electrical excitability of these cardiac organoids by improving the three-dimensional organization of the cells, increasing cellular elongation and enhancing Connexin-43 presence.

  18. Wave trains induced by circularly polarized electric fields in cardiac tissues.

    Science.gov (United States)

    Feng, Xia; Gao, Xiang; Tang, Juan-Mei; Pan, Jun-Ting; Zhang, Hong

    2015-08-25

    Clinically, cardiac fibrillation caused by spiral and turbulent waves can be terminated by globally resetting electric activity in cardiac tissues with a single high-voltage electric shock, but it is usually associated with severe side effects. Presently, a promising alternative uses wave emission from heterogeneities induced by a sequence of low-voltage uniform electric field pulses. Nevertheless, this method can only emit waves locally near obstacles in turbulent waves and thereby requires multiple obstacles to globally synchronize myocardium and thus to terminate fibrillation. Here we propose a new approach using wave emission from heterogeneities induced by a low-voltage circularly polarized electric field (i.e., a rotating uniform electric field). We find that, this approach can generate circular wave trains near obstacles and they propagate outwardly. We study the characteristics of such circular wave trains and further find that, the higher-frequency circular wave trains can effectively suppress spiral turbulence.

  19. Effect of the sphingosine kinase 1 selective inhibitor, PF-543 on arterial and cardiac remodelling in a hypoxic model of pulmonary arterial hypertension.

    Science.gov (United States)

    MacRitchie, Neil; Volpert, Giora; Al Washih, Mohammed; Watson, David G; Futerman, Anthony H; Kennedy, Simon; Pyne, Susan; Pyne, Nigel J

    2016-08-01

    Recent studies have demonstrated that the expression of sphingosine kinase 1, the enzyme that catalyses formation of the bioactive lipid, sphingosine 1-phosphate, is increased in lungs from patients with pulmonary arterial hypertension. In addition, Sk1(-/-) mice are protected from hypoxic-induced pulmonary arterial hypertension. Therefore, we assessed the effect of the sphingosine kinase 1 selective inhibitor, PF-543 and a sphingosine kinase 1/ceramide synthase inhibitor, RB-005 on pulmonary and cardiac remodelling in a mouse hypoxic model of pulmonary arterial hypertension. Administration of the potent sphingosine kinase 1 inhibitor, PF-543 in a mouse hypoxic model of pulmonary hypertension had no effect on vascular remodelling but reduced right ventricular hypertrophy. The latter was associated with a significant reduction in cardiomyocyte death. The protection involves a reduction in the expression of p53 (that promotes cardiomyocyte death) and an increase in the expression of anti-oxidant nuclear factor (erythroid-derived 2)-like 2 (Nrf-2). In contrast, RB-005 lacked effects on right ventricular hypertrophy, suggesting that sphingosine kinase 1 inhibition might be nullified by concurrent inhibition of ceramide synthase. Therefore, our findings with PF-543 suggest an important role for sphingosine kinase 1 in the development of hypertrophy in pulmonary arterial hypertension.

  20. 前列地尔对心力衰竭患者心脏功能和心室重构影响%The Effect of Alprostadil on Cardiac Function and Ventricular Remodeling of Patients with Cardiac Failure

    Institute of Scientific and Technical Information of China (English)

    朱鹏程; 林镇荣; 陈庆超; 杨锡泉; 张琳

    2015-01-01

    Objective:To explore the effect of alprostadil on cardiac function and ventricular remodeling of patients with cardiac failure. Method:80 patients with cardiac failure in Overseas Chinese Hospital of Raoping County were divided into research group (n=40) and control group (n=40) randomly from Aug 2013 to May 2015. The research group was treated by alprostadil based on the conventional methods in the control group. There were no differences in the baseline data including age, history, primary disease and ventricular rate between the two groups. Alprostadil was added 10 μg/d for 10-14 days in research group. The differences on cardiac function and ventricular remodeling were compared after 2 weeks after treatment between the two groups. Results:Compared with the control group,there were shorter left ventricular end diastolic diameter,larger left ventricular ejection fraction, longer walking distance in 6 minutes and slower resting heart rate,and higher the total effective rate in the research group,all P<0.01.There were no severe side actions in the research group. Conclusion:It is effective and safe in patients with cardiac failure treated by Alprostadil. Alprostadil could increase cardiac function and improve ventricular remodeling and could be used more popular in patients with cardiac failure.%目的:探讨前列地尔对心力衰竭患者心脏功能和心室重构的影响。方法:将2013年8月至2015年5月广东省潮州市饶平县华侨医院心内科收治的心力衰竭患者80例随机分为对照组和研究组各40例,两组年龄、病程、原发病和心室率等差异无显著性(P >0.05);对照组按常规治疗,研究组在对照组治疗的基础上加用前列地尔10 ug/次,每日1次,持续10-14 d,2周后比较两组治疗前后心脏功能和心室重构的变化。结果:与对照组相比,治疗后研究组的左室舒张末期内径缩小,左室射血分数增高,6 min步行距离延长,静

  1. Forward and inverse problem for cardiac magnetic field and electric potential using two boundary element methods

    Science.gov (United States)

    Tang, Fa-Kuan; Wang, Qian; Hua, Ning; Tang, Xue-Zheng; Lu, Hong; Ma, Ping

    2010-12-01

    This paper discusses the forward and inverse problem for cardiac magnetic fields and electric potentials. A torso-heart model established by boundary element method (BEM) is used for studying the distributions of cardiac magnetic fields and electric potentials. Because node-to-node and triangle-to-triangle BEM can lead to discrepant field distributions, their properties and influences are compared. Then based on constructed torso-heart model and supposed current source functional model—current dipole array, the magnetic and electric imaging by optimal constrained linear inverse method are applied at the same time. Through figure and reconstructing parameter comparison, though the magnetic current dipole array imaging possesses better reconstructing effect, however node-to-node BEM and triangle-to-triangle BEM make little difference to magnetic and electric imaging.

  2. Attenuation of salt-induced cardiac remodeling and diastolic dysfunction by the GPER agonist G-1 in female mRen2.Lewis rats.

    Directory of Open Access Journals (Sweden)

    Jewell A Jessup

    Full Text Available INTRODUCTION: The G protein-coupled estrogen receptor (GPER is expressed in various tissues including the heart. Since the mRen2.Lewis strain exhibits salt-dependent hypertension and early diastolic dysfunction, we assessed the effects of the GPER agonist (G-1, 40 nmol/kg/hr for 14 days or vehicle (VEH, DMSO/EtOH on cardiac function and structure. METHODS: Intact female mRen2.Lewis rats were fed a normal salt (0.5% sodium; NS diet or a high salt (4% sodium; HS diet for 10 weeks beginning at 5 weeks of age. RESULTS: Prolonged intake of HS in mRen2.Lewis females resulted in significantly increased blood pressure, mildly reduced systolic function, and left ventricular (LV diastolic compliance (as signified by a reduced E deceleration time and E deceleration slope, increased relative wall thickness, myocyte size, and mid-myocardial interstitial and perivascular fibrosis. G-1 administration attenuated wall thickness and myocyte hypertrophy, with nominal effects on blood pressure, LV systolic function, LV compliance and cardiac fibrosis in the HS group. G-1 treatment significantly increased LV lusitropy [early mitral annular descent (e'] independent of prevailing salt, and improved the e'/a' ratio in HS versus NS rats (P<0.05 as determined by tissue Doppler. CONCLUSION: Activation of GPER improved myocardial relaxation in the hypertensive female mRen2.Lewis rat and reduced cardiac myocyte hypertrophy and wall thickness in those rats fed a high salt diet. Moreover, these advantageous effects of the GPER agonist on ventricular lusitropy and remodeling do not appear to be associated with overt changes in blood pressure.

  3. The Relationship among Carotid Artery Remodeling, Cardiac Geometry, and Serum N-Terminal Pro-B-Type Natriuretic Peptide Level in Asymptomatic Asians: Sex-Differences and Longitudinal GEE Study.

    Directory of Open Access Journals (Sweden)

    Chen-Yen Chien

    Full Text Available Carotid artery remodeling is known to be associated with a variety of cardiovascular diseases. However, there is limited information regarding gender differences in carotid remodeling. We sought to investigate the associations among blood pressure (BP, carotid artery remodeling and cardiac geometries, and further explore gender differences.In a large cohort of asymptomatic adults undergoing routine health screening with repeated observations, we related measures of carotid artery diameter (CCAD to various BP components, cardiac geometries and blood N-terminal pro-brain natriuretic peptide (NT-proBNP level, both from baseline cross-sectional and longitudinal dataset using generalized estimating equations (GEE.A total of 2,914 person-visits (baseline: n=998, mean age: 47 ± 8.9 years, 34% female were studied (median: 6 ± 1.73 years follow up. We observed that CCAD was larger in men (p=300pg/mL; AUROC: 0.79, CCAD cut-off: 7.95mm, all p<0.05, which remained significant in multi-variate and longitudinal models. There was a prominent sex interaction (p for interaction with age and systolic BP: 0.004 and 0.028 respectively, where the longitudinal associations of age and systolic BP with increasing CCAD as more pronounced in women than men.These data demonstrated that carotid artery remodeling may parallel subclinical biomarker of cardiac dysfunction, and further showed greater effects of aging and higher blood pressure on such remodeling process in women than men. Further study is warranted to understand how this predisposition of elderly hypertensive women to vascular remodeling may play a role in clinical settings.

  4. Cardiac remodeling as a consequence of atrial fibrillation: An anatomical study of perfusion-fixed human heart specimens

    Institute of Scientific and Technical Information of China (English)

    Christopher D Rolfes; Stephen A Howard; Ryan P Goff; Paul A Iaizzo

    2011-01-01

    Background Atrial fibrillation(AF)causes a continuum of atrial anatomical remodeling.Methods Using a library of perfusion-fixed human hearts,specimens with AF were compared to controls.During this preliminary assessment study,direct measurements were taken of atrial volume,pulmonary vein(PV)circumference,and left atrial(LA)wall thicknesses.Results Hearts with AF typically had larger atrial volumes,as well as a much larger variation in volume compared to controls(range of 59.6-227.1 mL in AF hearts compared to 65.1-115.9 mL in controls).For all hearts,right PVs were larger than left PVs(mean: 171.4±84.6 mm' for right and 118.2±50.1 mm2 for left P<0.005).LA wall thicknesses ranged from 0.7 mm to 3.1 min for both AF and control hearts.Conclusions Hearts with AF had a large range of sizes which is consistent with the progression of atrial remodeling during AF.The large range of thicknesses will influence the amount of energy needed to create transmural lesions during ablation procedures.

  5. Hemodynamic Sensor in Cardiac Implantable Electric Devices: The Endocardial Accelaration Technology

    Directory of Open Access Journals (Sweden)

    Stefania Sacchi

    2013-01-01

    Full Text Available There have been substantial progresses in the technology of cardiac implantable electric devices (CIEDs during the past decades. One of the progresses is represented by the development of a hemodynamic sensor embedded at the tip of a pacing lead that measures myocardial contractility by the analysis of myocardial mechanical vibrations occurring during the cardiac cycle. This sensor, providing continuous hemodynamic monitoring, could play an important role in clinical practice because of several clinical applications in CIEDs recipients. The objectives of this work are to report how this sensor operates and to review the main findings about its clinical applications.

  6. Modeling cardiac mechano-electrical feedback using reaction-diffusion-mechanics systems

    Science.gov (United States)

    Keldermann, R. H.; Nash, M. P.; Panfilov, A. V.

    2009-06-01

    In many practically important cases, wave propagation described by the reaction-diffusion equation initiates deformation of the medium. Mathematically, such processes are described by coupled reaction-diffusion-mechanics (RDM) systems. RDM systems were recently used to study the effects of deformation on wave propagation in cardiac tissue, so called mechano-electrical feedback (MEF). In this article, we review the results of some of these studies, in particular those relating to the effects of deformation on pacemaker activity and spiral wave dynamics in the heart. We also provide brief descriptions of the numerical methods used, and the underlying cardiac physiology.

  7. Turbulent electrical activity at sharp-edged inexcitable obstacles in a model for human cardiac tissue.

    Science.gov (United States)

    Majumder, Rupamanjari; Pandit, Rahul; Panfilov, A V

    2014-10-01

    Wave propagation around various geometric expansions, structures, and obstacles in cardiac tissue may result in the formation of unidirectional block of wave propagation and the onset of reentrant arrhythmias in the heart. Therefore, we investigated the conditions under which reentrant spiral waves can be generated by high-frequency stimulation at sharp-edged obstacles in the ten Tusscher-Noble-Noble-Panfilov (TNNP) ionic model for human cardiac tissue. We show that, in a large range of parameters that account for the conductance of major inward and outward ionic currents of the model [fast inward Na(+) current (INa), L-type slow inward Ca(2+) current (ICaL), slow delayed-rectifier current (IKs), rapid delayed-rectifier current (IKr), inward rectifier K(+) current (IK1)], the critical period necessary for spiral formation is close to the period of a spiral wave rotating in the same tissue. We also show that there is a minimal size of the obstacle for which formation of spirals is possible; this size is ∼2.5 cm and decreases with a decrease in the excitability of cardiac tissue. We show that other factors, such as the obstacle thickness and direction of wave propagation in relation to the obstacle, are of secondary importance and affect the conditions for spiral wave initiation only slightly. We also perform studies for obstacle shapes derived from experimental measurements of infarction scars and show that the formation of spiral waves there is facilitated by tissue remodeling around it. Overall, we demonstrate that the formation of reentrant sources around inexcitable obstacles is a potential mechanism for the onset of cardiac arrhythmias in the presence of a fast heart rate.

  8. Cardiac microstructure: implications for electrical propagation and defibrillation in the heart.

    Science.gov (United States)

    Hooks, Darren A; Tomlinson, Karl A; Marsden, Scott G; LeGrice, Ian J; Smaill, Bruce H; Pullan, Andrew J; Hunter, Peter J

    2002-08-23

    Our understanding of the electrophysiological properties of the heart is incomplete. We have investigated two issues that are fundamental to advancing that understanding. First, there has been widespread debate over the mechanisms by which an externally applied shock can influence a sufficient volume of heart tissue to terminate cardiac fibrillation. Second, it has been uncertain whether cardiac tissue should be viewed as an electrically orthotropic structure, or whether its electrical properties are, in fact, isotropic in the plane orthogonal to myofiber direction. In the present study, a computer model that incorporates a detailed three-dimensional representation of cardiac muscular architecture is used to investigate these issues. We describe a bidomain model of electrical propagation solved in a discontinuous domain that accurately represents the microstructure of a transmural block of rat left ventricle. From analysis of the model results, we conclude that (1) the laminar organization of myocytes determines unique electrical properties in three microstructurally defined directions at any point in the ventricular wall of the heart, and (2) interlaminar clefts between layers of cardiomyocytes provide a substrate for bulk activation of the ventricles during defibrillation.

  9. microRNAs and Cardiovascular Remodeling.

    Science.gov (United States)

    Ono, Koh

    2015-01-01

    Heart failure (HF) is associated with significant morbidity and mortality attributable largely to structural changes in the heart and with associated cardiac dysfunction. Remodeling is defined as alteration of the mass, dimensions, or shape of the heart (termed cardiac or ventricular remodeling) and vessels (vascular remodeling) in response to hemodynamic load and/or cardiovascular injury in association with neurohormonal activation. Remodeling may be described as physiologic or pathologic; alternatively, remodeling may be classified as adaptive or maladaptive. The importance of remodeling as a pathogenic mechanism has been controversial because factors leading to remodeling as well as the remodeling itself may be major determinants of patients' prognosis. The basic mechanisms of cardiovascular remodeling, and especially the roles of microRNAs in HF progression and vascular diseases, will be reviewed here.

  10. Tenascin-x facilitates myocardial fibrosis and cardiac remodeling through transforming growth factor-β1 and peroxisome proliferator-activated receptor γ in alcoholic cardiomyopathy

    Institute of Scientific and Technical Information of China (English)

    JING Ling; ZHOU Li-jun; ZHANG Feng-min; LI Wei-min; SANG Ying

    2011-01-01

    Background Tenascin-x, an extracellular matrix glycoprotein exclusively expressed in fibroblasts, can mediate fibrosis in the presence of collagen. Therefore, we have investigated its potential role in facilitating myocardial fibrosis and cardiac remodeling via the transforming growth factor-lβ1 and peroxisome proliferator-activated receptor γ(TGFβ1-PPARγ) pathway in alcoholic cardiomyopathy (ACM).Methods Experimental animals were divided into control (group A) and tenascin-x knock-out groups (group B)receiving alcohol. Six months post treatment, cardiac ejections fraction (EF), fractional shortening (FS), left ventricle end-diastole internal diameter (LVEDd) and collagen column fraction (CVF) were observed. Tenascin-x, smad-3, TGFβ1,smad-7 and PPARγ protein expression levels were detected by Western blotting.Results Six months post treatment, EF and FS values were higher in group B than in group A (P <0.05 and P <0.01,respectively), while LVEDd and CVF were lower in group B (P <0.05 and P <0.01, respectively). Tenascin-x, smad-3 and TGFβ1 protein expression levels were higher in group A, while smad-7 and PPARY levels were lower than in group B (P<0.01), as measured by immunohistochemistry and Western blotting. Tenascin-x protein expression was negatively correlated with EF, FS, smad-7 and PPARγ, and positively correlated with LVEDd, CVF, smad-3, and TGFβ1 (P <0.001).Conclusion Tenascin-x is an initiator of myocardial fibrosis and ACM development via upregulation of TGFβ1 and downregulation of PPARγ.

  11. High intensity interval and endurance training have opposing effects on markers of heart failure and cardiac remodeling in hypertensive rats.

    Science.gov (United States)

    Holloway, Tanya M; Bloemberg, Darin; da Silva, Mayne L; Simpson, Jeremy A; Quadrilatero, Joe; Spriet, Lawrence L

    2015-01-01

    There has been re-emerging interest and significant work dedicated to investigating the metabolic effects of high intensity interval training (HIIT) in recent years. HIIT is considered to be a time efficient alternative to classic endurance training (ET) that elicits similar metabolic responses in skeletal muscle. However, there is a lack of information on the impact of HIIT on cardiac muscle in disease. Therefore, we determined the efficacy of ET and HIIT to alter cardiac muscle characteristics involved in the development of diastolic dysfunction, such as ventricular hypertrophy, fibrosis and angiogenesis, in a well-established rodent model of hypertension-induced heart failure before the development of overt heart failure. ET decreased left ventricle fibrosis by ~40% (P HIIT did not decrease existing fibrosis, and HIIT animals displayed a 20% increase in left ventricular mass (PHIIT also increased brain natriuretic peptide by 50% (PHIIT promoted a pathological adaptation in the left ventricle in the presence of hypertension, highlighting the need for further research on the widespread effects of HIIT in the presence of disease.

  12. Long-Term Overexpression of Hsp70 Does Not Protect against Cardiac Dysfunction and Adverse Remodeling in a MURC Transgenic Mouse Model with Chronic Heart Failure and Atrial Fibrillation.

    Science.gov (United States)

    Bernardo, Bianca C; Sapra, Geeta; Patterson, Natalie L; Cemerlang, Nelly; Kiriazis, Helen; Ueyama, Tomomi; Febbraio, Mark A; McMullen, Julie R

    2015-01-01

    Previous animal studies had shown that increasing heat shock protein 70 (Hsp70) using a transgenic, gene therapy or pharmacological approach provided cardiac protection in models of acute cardiac stress. Furthermore, clinical studies had reported associations between Hsp70 levels and protection against atrial fibrillation (AF). AF is the most common cardiac arrhythmia presenting in cardiology clinics and is associated with increased rates of heart failure and stroke. Improved therapies for AF and heart failure are urgently required. Despite promising observations in animal studies which targeted Hsp70, we recently reported that increasing Hsp70 was unable to attenuate cardiac dysfunction and pathology in a mouse model which develops heart failure and intermittent AF. Given our somewhat unexpected finding and the extensive literature suggesting Hsp70 provides cardiac protection, it was considered important to assess whether Hsp70 could provide protection in another mouse model of heart failure and AF. The aim of the current study was to determine whether increasing Hsp70 could attenuate adverse cardiac remodeling, cardiac dysfunction and episodes of arrhythmia in a mouse model of heart failure and AF due to overexpression of Muscle-Restricted Coiled-Coil (MURC). Cardiac function and pathology were assessed in mice at approximately 12 months of age. We report here, that chronic overexpression of Hsp70 was unable to provide protection against cardiac dysfunction, conduction abnormalities, fibrosis or characteristic molecular markers of the failing heart. In summary, elevated Hsp70 may provide protection in acute cardiac stress settings, but appears insufficient to protect the heart under chronic cardiac disease conditions.

  13. Onset of hypertension during pregnancy is associated with long-term worse blood pressure control and adverse cardiac remodeling.

    Science.gov (United States)

    Mesquita, Roberto F; Reis, Muriel; Beppler, Ana Paula; Bellinazzi, Vera Regina; Mattos, Sandra S; Lima-Filho, José L; Cipolli, José A; Coelho-Filho, Otavio R; Pio-Magalhães, José A; Sposito, Andrei C; Matos-Souza, José R; Nadruz, Wilson

    2014-11-01

    Up to 20% of women with hypertensive pregnancy disorders might persist with chronic hypertension. This study compared clinical and echocardiographic features between women whose hypertension began as hypertensive pregnancy disorders (PH group) and women whose diagnosis of hypertension did not occur during pregnancy (NPH group). Fifty PH and 100 NPH women were cross-sectionally evaluated by clinical, laboratory, and echocardiography analysis, and the groups were matched by duration of hypertension. PH exhibited lower age (46.6 ± 1.4 vs. 65.3 ± 1.1 years; P < .001), but higher systolic (159.8 ± 3.9 vs. 148.0 ± 2.5 mm Hg; P = .009) and diastolic (97.1 ± 2.4 vs. 80.9 ± 1.3 mm Hg; P < .001) blood pressure than NPH, although used more antihypertensive classes (3.4 ± 0.2 vs. 2.6 ± 0.1; P < .001). Furthermore, PH showed higher left ventricular wall thickness and increased prevalence of concentric hypertrophy than NPH after adjusting for age and blood pressure. In conclusion, this study showed that PH may exhibit worse blood pressure control and adverse left ventricular remodeling compared with NPH.

  14. Unpinning of rotating spiral waves in cardiac tissues by circularly polarized electric fields

    Science.gov (United States)

    Feng, Xia; Gao, Xiang; Pan, De-Bei; Li, Bing-Wei; Zhang, Hong

    2014-04-01

    Spiral waves anchored to obstacles in cardiac tissues may cause lethal arrhythmia. To unpin these anchored spirals, comparing to high-voltage side-effect traditional therapies, wave emission from heterogeneities (WEH) induced by the uniform electric field (UEF) has provided a low-voltage alternative. Here we provide a new approach using WEH induced by the circularly polarized electric field (CPEF), which has higher success rate and larger application scope than UEF, even with a lower voltage. And we also study the distribution of the membrane potential near an obstacle induced by CPEF to analyze its mechanism of unpinning. We hope this promising approach may provide a better alternative to terminate arrhythmia.

  15. Improvement of cardiac function and reversal of gap junction remodeling by Neuregulin-1β in volume-overloaded rats with heart failure

    Institute of Scientific and Technical Information of China (English)

    Xue-Hui Wang; Xiao-Zhen Zhuo; Ya-Juan Ni; Min Gong; Ting-Zhong Wang; Qun Lu; Ai-Qun Ma

    2012-01-01

    Objective We performed experiments using Neuregulin-1β (NRG-1β) treatment to determine a mechanism for the protective role derived from its beneficial effects by remodeling gap junctions (GJs) during heart failure (HF). Methods Rat models of HF were established by aortocaval fistula. Forty-eight rats were divided randomly into the HF (HF, n = 16), NRG-1β treatment (NRG, n = 16), and sham operation (S, n = 16) group. The rats in the NRG group were administered NRG-1β (10 μg/kg per day) for 7 days via the tail vein, whereas the other groups were injected with the same doses of saline. Twelve weeks after operation, Connexin 43 (Cx43) expression in single myocytes obtained from the left ventricle was determined by immunocytochemistry. Total protein was extracted from frozen left ventricular tissues for immunoblotting assay, and the ultrastructure of myocytes was observed by transmission electron microscopy. Results Compared with the HF group, the cardiac function of rats in the NRG group was markedly improved, irregular distribution and deceased Cx43 expression were relieved. The ultrastructure of myocytes was seriously damaged in HF rats, and NRG-1β reduced these pathological damages. Conclusions Short-term NRG-1β treatment can rescue pump failure in experimental models of volume overload-induced HF, which is related to the recovery of GJs structure and the improvement of Cx43 expression.

  16. 心脏重构中微 RNA 的作用%The Role of MicroRNAs in the Cardiac Remodeling

    Institute of Scientific and Technical Information of China (English)

    李歆跃(综述); 杨巍(审校)

    2015-01-01

    心脏重构是各类心血管疾病的重要进程之一,包括心肌梗死、瓣膜疾病、心肌炎、扩张型心肌病、心房颤动和心力衰竭等。多项研究发现,微 RNA( miRNA)与此过程息息相关,并且在体内和体外实验模型中都证实了 miRNA 广泛地参与此进程。临床上,miRNA 已作为潜在的诊断指标和治疗靶点被重视。该文就近年的热点及被重点研究的几种 miRNA 进行综述。%Cardiac remodeling is the key process in cardiovascular diseases including myocardial infarc-tion,valvular disease,myocarditis,dilated cardiomyopathy,atrial fibrillation and heart failure.Both in vitro and vivo models have proved that microRNAs play an important role in a wide range of processes.Clinically, miRNAs have been attached much attention as the potential diagnostic biomarkers and novel therapeutic tar-get recently.Here is to make a review of the focal points and mostly studied miRNA in the recent years.

  17. Adenosine A2A  receptor agonist prevents cardiac remodeling and dysfunction in spontaneously hypertensive male rats after myocardial infarction

    Directory of Open Access Journals (Sweden)

    da Silva JS

    2017-03-01

    Full Text Available Jaqueline S da Silva,1 Daniele Gabriel-Costa,1 Roberto T Sudo,1 Hao Wang,2 Leanne Groban,2 Emanuele B Ferraz,3 José Hamilton M Nascimento,3 Carlos Alberto M Fraga,1 Eliezer J Barreiro,1 Gisele Zapata-Sudo1 1Research Program Development of Drugs, Institute of Biomedical Sciences, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; 2Department of Anesthesiology, Wake Forest School of Medicine, Winston-Salem, NC, USA; 3Institute of Biophysics Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil Background: This work evaluated the hypothesis that 3,4-methylenedioxybenzoyl-2- thienylhydrazone (LASSBio-294, an agonist of adenosine A2A  receptor, could be beneficial for preventing cardiac dysfunction due to hypertension associated with myocardial infarction (MI. Methods: Male spontaneously hypertensive rats (SHR were randomly divided into four groups (six animals per group: sham-operation (SHR-Sham, and myocardial infarction rats (SHR-MI were treated orally either with vehicle or LASSBio-294 (10 and 20 mg.kg-1.d-1 for 4 weeks. Echocardiography and in vivo hemodynamic parameters measured left ventricle (LV structure and function. Exercise tolerance was evaluated using a treadmill test. Cardiac remodeling was accessed by LV collagen deposition and tumor necrosis factor α expression. Results: Early mitral inflow velocity was significantly reduced in the SHR-MI group, and there was significant recovery in a dose-dependent manner after treatment with LASSBio-294. Exercise intolerance observed in the SHR-MI group was prevented by 10 mg.kg-1.d-1 of LASSBio-294, and exercise tolerance exceeded that of the SHR-Sham group at 20 mg.kg-1.d-1. LV end-diastolic pressure increased after MI, and this was prevented by 10 and 20 mg.kg-1.d-1 of LASSBio-294. Sarcoplasmic reticulum Ca2+ ATPase levels were restored in a dose-dependent manner after treatment with LASSBio-294. Fibrosis and inflammatory processes were also

  18. Assessment of cardiac remodeling in asymptomatic mitral regurgitation for surgery timing: a comparative study of echocardiography and magnetic resonance imaging

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    Ozdogan Oner

    2010-08-01

    Full Text Available Abstract Background Early surgery is recommended for asymptomatic severe mitral regurgitation (MR, because of increased postoperative left ventricular (LV dysfunction in patients with late surgery. On the other hand, recent reports emphasized a "watchful waiting" process for the determination of the proper time of mitral valve surgery. In our study, we compared magnetic resonance imaging (MRI and transthoracic echocardiography to evaluate the LV and left atrial (LA remodeling; for better definitions of patients that may benefit from early valve surgery. Methods Twenty-one patients with moderate to severe asymptomatic MR were evaluated by echocardiography and MRI. LA and LV ejection fractions (EFs were calculated by echocardiography and MRI. Pulmonary veins (PVs were measured from vein orifices in diastole and systole from the tangential of an imaginary circle that completed LA wall. Right upper PV indices were calculated with the formula; (Right upper PV diastolic diameter- Right upper PV systolic diameter/Right upper PV diastolic diameter. Results In 9 patients there were mismatches between echocardiography and MRI measurements of LV EF. LV EFs were calculated ≥60% by echocardiography, meanwhile 0.05. However, both right upper PV indices (0.16 ± 0.06 vs. 0.24 ± 0.08, p: 0.024 and LA EFs (0.19 ± 0.09 vs. 0.33 ± 0.14, p: 0.025 were significantly decreased in patients with depressed EFs when compared to patients with normal EFs. Conclusions MRI might be preferred when small changes in functional parameters like LV EF, LA EF, and PV index are of clinical importance to disease management like asymptomatic MR patients that we follow up for appropriate surgery timing.

  19. Alterations in the expression of atrial calpains in electrical and structural remodeling during aging and atrial fibrillation.

    Science.gov (United States)

    Xu, Guo-Jun; Gan, Tian-Yi; Tang, Bao-Peng; Chen, Zu-Heng; Mahemuti, Ailiman; Jiang, Tao; Song, Jian-Guo; Guo, Xia; Li, Yao-Dong; Zhou, Xian-Hui; Zhang, Yu; Li, Jin-Xin

    2013-11-01

    The aim of this study was to investigate the correlation between the change in the expression of atrial calpains and electrical, molecular and structural remodeling during aging and atrial fibrillation (AF). Adult and aged canines in sinus rhythm (SR) and with persistent AF (induced by rapid atrial pacing) were investigated. A whole-cell patch clamp was used to measure the L-type Ca2+ current (ICa-L) in cells in the left atrium. The mRNA and protein expression of the L-type calcium channel alc subunit (LVDCCa1c) and calpains were measured by quantitative (q)PCR and western blot analysis. Histopathological and ultrastructural changes were analyzed via light and electron microscopy. The quantity of apoptotic myocytes was determined by a terminal deoxynucleotidyl-transferase-mediated dUTP nick end labeling (TUNEL) assay. In SR groups, atrial cells of the aged canines exhibited a longer action potential (AP) duration to 90% repolarization (APD90), lower AP plateau potential and peak ICa-L current densities (Pcalpain 1 was increased in the adult and the aged groups with AF (Pcalpain 1. The general pathophysiological alterations in normal aged atria may therefore produce a substrate that is conducive to AF.

  20. Comparison of Transcutaneous Electrical Nerve Stimulation and Parasternal Block for Postoperative Pain Management after Cardiac Surgery

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    Nilgun Kavrut Ozturk

    2016-01-01

    Full Text Available Background. Parasternal block and transcutaneous electrical nerve stimulation (TENS have been demonstrated to produce effective analgesia and reduce postoperative opioid requirements in patients undergoing cardiac surgery. Objectives. To compare the effectiveness of TENS and parasternal block on early postoperative pain after cardiac surgery. Methods. One hundred twenty patients undergoing cardiac surgery were enrolled in the present randomized, controlled prospective study. Patients were assigned to three treatment groups: parasternal block, intermittent TENS application, or a control group. Results. Pain scores recorded 4 h, 5 h, 6 h, 7 h, and 8 h postoperatively were lower in the parasternal block group than in the TENS and control groups. Total morphine consumption was also lower in the parasternal block group than in the TENS and control groups. It was also significantly lower in the TENS group than in the control group. There were no statistical differences among the groups regarding the extubation time, rescue analgesic medication, length of intensive care unit stay, or length of hospital stay. Conclusions. Parasternal block was more effective than TENS in the management of early postoperative pain and the reduction of opioid requirements in patients who underwent cardiac surgery through median sternotomy. This trial is registered with Clinicaltrials.gov number NCT02725229.

  1. Embryonic Stem Cell-Derived Cardiomyocyte Heterogeneity and the Isolation of Immature and Committed Cells for Cardiac Remodeling and Regeneration

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    Kenneth R. Boheler

    2011-01-01

    Full Text Available Pluripotent stem cells represent one promising source for cell replacement therapy in heart, but differentiating embryonic stem cell-derived cardiomyocytes (ESC-CMs are highly heterogeneous and show a variety of maturation states. In this study, we employed an ESC clonal line that contains a cardiac-restricted ncx1 promoter-driven puromycin resistance cassette together with a mass culture system to isolate ESC-CMs that display traits characteristic of very immature CMs. The cells display properties of proliferation, CM-restricted markers, reduced mitochondrial mass, and hypoxia-resistance. Following transplantation into rodent hearts, bioluminescence imaging revealed that immature cells, but not more mature CMs, survived for at least one month following injection. These data and comparisons with more mature cells lead us to conclude that immature hypoxia resistant ESC-CMs can be isolated in mass in vitro and, following injection into heart, form grafts that may mediate long-term recovery of global and regional myocardial contractile function following infarction.

  2. Assessment of cardiac stroke volume in patients with implanted cardiac pacemaker using parametric electrical impedance tomography: a theoretical 2D study.

    Science.gov (United States)

    Mhajna, Muhammad; Abboud, Shimon

    2013-05-01

    The present theoretical study examines the ability to estimate cardiac stroke volume (CSV) in patients with implanted cardiac pacemaker using parametric electrical impedance tomography (pEIT) in a 2D computerized model of the thorax. CSV is a direct indicator of the cardiac pumping efficiency. The commonly used methods for measuring CSV require the invasive procedure of right heart catheterization or use expensive imaging techniques (i.e., MRI). Hence, experience with these techniques for diagnosis and monitoring has been limited to hospitalized patients. In the present study, pEIT scheme was applied in a computerized 2D model of the human thorax with implanted cardiac device to determine the left ventricular (LV) volume at different cardiac cycle phases. The LV was simulated as a prolate ellipse with its axes' lengths as the reconstruction parameters while all other geometries and conductivity values remained constant. An optimization was carried out in order to ensure that the ellipse is the appropriate model for the LV at each cardiac cycle phase. LV volumes calculated by both the pEIT algorithm and the ellipsoid model are consistent. A high correlation (ρ = 0.99) between the true and reconstructed volumes was found. The SV calculation error was ∼1%. The results suggest that the LV volume can be estimated using the pEIT method in a 2D computerized model, and that the method has the potential to be used for monitoring patients with implanted cardiac pacemaker.

  3. Mechanisms of electrical activation and conduction in the gastrointestinal system: lessons from cardiac electrophysiology

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    Gary eTse

    2016-05-01

    Full Text Available The gastrointestinal (GI tract is an electrically excitable organ system containing multiple cell types, which coordinate electrical activity propagating through this tract. Disruption in its normal electrophysiology is observed in a number of GI motility disorders. However, this is not well characterized and the field of GI electrophysiology is much less developed compared to the cardiac field. The aim of this article is to use the established knowledge of cardiac electrophysiology to shed light on the mechanisms of electrical activation and propagation along the GI tract, and how abnormalities in these processes lead to motility disorders and suggest better treatment options based on this improved understanding. In the first part of the article, the ionic contributions to the generation of GI slow wave and the cardiac action potential (AP are reviewed. Propagation of these electrical signals can be described by the core conductor theory in both systems. However, specifically for the GI tract, the following unique properties are observed: changes in slow wave frequency along its length, periods of quiescence, synchronization in short distances and desynchronization over long distances. These are best described by a coupled oscillator theory. Other differences include the diminished role of gap junctions in mediating this conduction in the GI tract compared to the heart. The electrophysiology of conditions such as gastroesophageal reflux disease and gastroparesis, and functional problems such as irritable bowel syndrome are discussed in detail, with reference to ion channel abnormalities and potential therapeutic targets. A deeper understanding of the molecular basis and physiological mechanisms underlying GI motility disorders will enable the development of better diagnostic and therapeutic tools and the advancement of this field.

  4. Cardioprotective effects of simvastatin on reversing electrical remodeling induced by myocardial ischemia-reperfusion in normocholesterolemic rabbits

    Institute of Scientific and Technical Information of China (English)

    DING Chao; FU Xiang-hua; HE Zhen-shan; CHEN Hui-xiao; XUE Ling; LI Jun-xia

    2008-01-01

    Background Recent studies have revealed that pretreatment with statin is effective in preventing armythmia,but its electrophysiological mechanism is unclear.This study was conducted to investigate the cardioprotective effects of simvastatin on reversing electrical remodeling in left ventricular myocytes of rabbit heart undergoing ischemia-reperfusion.so as to explore the ionic mechanism responsible for the anti-arrhythmic effect of statin.Methods Forty-five rabbits were randomly divided into three groups:ischemic-reperfusion group(I-R),simvastatin intervention group (Statin) and sham-operated control group(CON).Anesthetized rabbits were subjected to 30-minute ischemia by ligation of the left anterior descending coronary artery and a 60-minute reperfusion after a 3-day administration of oral simvastatin of 5 mg·kg-1·d-1 in the Statin group or a placebo in the I-R group.Single ventricular myocytes were isolated enzymatically from the epicardial zone of the infracted region derived from the hearts in the I-R and Statin group and the same anatomical region in the CON animals.The whole cell patch-clamp technique was used to record membrane ionic currents,including sodium current(Ina),L-type calcium current(Ica-L)and transient outward potassium current(Ito).Simultaneously,the level of serum cholesterol was examined.Results There was no significant difference in the serum cholesterol concentration among the three groups.The peak Ina current density(at-30 mV)was significantly decreased in I-R((-22.46±5.32)pA/pF,n=12)compared with CON ((-42.78±5.48)pA/pF,n=16,P<0.01)and Statin((-40.66±5.89)pA/pF,n=15,P<0.01),while the peak Ina current density in the Statin group was not different from CON(P>0.05).The peak Ica-L current density(at 0 mV)was significantly increased in I-R((-4.34±0.92)pA/pF,n=15)compared with CON((-3.13±1.22)pA/pF,n=13,P<0.05)and Statin ((-3.46±0.85)pA/pF,n=16,P<0.05),while the Peak Ica-L current density in Statin was not different from CON

  5. Optimisation of a Generic Ionic Model of Cardiac Myocyte Electrical Activity

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    Tianruo Guo

    2013-01-01

    Full Text Available A generic cardiomyocyte ionic model, whose complexity lies between a simple phenomenological formulation and a biophysically detailed ionic membrane current description, is presented. The model provides a user-defined number of ionic currents, employing two-gate Hodgkin-Huxley type kinetics. Its generic nature allows accurate reconstruction of action potential waveforms recorded experimentally from a range of cardiac myocytes. Using a multiobjective optimisation approach, the generic ionic model was optimised to accurately reproduce multiple action potential waveforms recorded from central and peripheral sinoatrial nodes and right atrial and left atrial myocytes from rabbit cardiac tissue preparations, under different electrical stimulus protocols and pharmacological conditions. When fitted simultaneously to multiple datasets, the time course of several physiologically realistic ionic currents could be reconstructed. Model behaviours tend to be well identified when extra experimental information is incorporated into the optimisation.

  6. Echocardiography integrated ACLS protocol versus conventional cardiopulmonary resuscitation in patients with pulseless electrical activity cardiac arrest

    Institute of Scientific and Technical Information of China (English)

    Mojtaba Chardoli; Farhad Heidari; Helaleh Rabiee; Mahdi Sharif-Alhoseini; Hamid Shokoohi; Vafa Rahimi-Movaghar

    2012-01-01

    Objective: To examine the utility of bedside echocardiography in detecting the reversible causes of pulseless electrical activity (PEA) cardiac arrest and predicting the resuscitation outcomes.Methods: In this prospective interventional study,patients presenting with PEA cardiac arrest were randomized into two groups.In Group A,ultrasound trained emergency physicians performed echocardiography evaluating cardiac activity,right ventricle dilation,left ventricle function,pericardial effusion/tamponade and ⅣC size along with the advanced cardiac life support (ACLS) protocol.Patients in Group B solely underwent ACLS protocol without applying echocardiography.The presence or absence of mechanical ventricular activity (MVA) and evidences of PEA reversible causes were recorded.The return of spontaneous circulation (ROSC) and death were evaluated in both groups.Results: One hundred patients with the mean age of (58±6.1) years were enrolled in this study.Fifty patients (Group A) had echocardiography detected in parallel with cardiopulmonary resuscitation (CPR).Among them,7 patients (14%) had pericardial effusion,11 (22%) had hypovolemia,and 39 (78%) were revealed the presence of MVA.In the pseudo PEA subgroup (presence of MVA),43% had ROSC (positive predictive value) and in the true PEA subgroup with cardiac standstill (absence of MVA),there was no recorded ROSC (negative predictive value).Among patients in Group B,no reversible etiology was detected.There was no significant difference in resuscitation results between Groups A and B observed (P=0.52).Conclusion: Bedside echocardiography can identify some reversible causes of PEA.However,there are no significant changes in survival outcome between the echo group and those with traditional CPR.

  7. Electrically conductive gold nanoparticle-chitosan thermosensitive hydrogels for cardiac tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Baei, Payam [Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran (Iran, Islamic Republic of); Cardiovascular Engineering Laboratory, Faculty of Biomedical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran (Iran, Islamic Republic of); Jalili-Firoozinezhad, Sasan [Department of Biomedicine and Surgery, University Hospital Basel, University of Basel, Hebelstrasse 20, CH-4031 Basel (Switzerland); Department of Bioengineeringand IBB - Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Lisboa (Portugal); Rajabi-Zeleti, Sareh [Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran (Iran, Islamic Republic of); Tafazzoli-Shadpour, Mohammad [Cardiovascular Engineering Laboratory, Faculty of Biomedical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran (Iran, Islamic Republic of); Baharvand, Hossein, E-mail: Baharvand@royaninstitute.org [Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran (Iran, Islamic Republic of); Department of Developmental Biology, University of Science and Culture, ACECR, Tehran (Iran, Islamic Republic of); Aghdami, Nasser, E-mail: Nasser.Aghdami@royaninstitute.org [Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran (Iran, Islamic Republic of)

    2016-06-01

    Injectable hydrogels that resemble electromechanical properties of the myocardium are crucial for cardiac tissue engineering prospects. We have developed a facile approach that uses chitosan (CS) to generate a thermosensitive conductive hydrogel with a highly porous network of interconnected pores. Gold nanoparticles (GNPs) were evenly dispersed throughout the CS matrix in order to provide electrical cues. The gelation response and electrical conductivity of the hydrogel were controlled by different concentrations of GNPs. The CS-GNP hydrogels were seeded with mesenchymal stem cells (MSCs) and cultivated for up to 14 days in the absence of electrical stimulations. CS-GNP scaffolds supported viability, metabolism, migration and proliferation of MSCs along with the development of uniform cellular constructs. Immunohistochemistry for early and mature cardiac markers showed enhanced cardiomyogenic differentiation of MSCs within the CS-GNP compared to the CS matrix alone. The results of this study demonstrate that incorporation of nanoscale electro-conductive GNPs into CS hydrogels enhances the properties of myocardial constructs. These constructs could find utilization for regeneration of other electroactive tissues. - Highlights: • Thermosensitive electro-conductive hydrogels were prepared from CS and GNPs. • Gelation time and conductivity were tuned by varying concentration of GNPs. • CS-2GNP with gelation time of 25.7 min and conductivity of 0.13 S·m{sup −1} was selected for in vitro studies. • CS-2GNP supported active metabolism, migration and proliferation of MSCs. • Expression of cardiac markers increased about two-fold in CS-2GNP compared to CS.

  8. [Effects and the mechanisms of cardiac short-term memory on cellular electrical excitability].

    Science.gov (United States)

    Wang, Juan; Zhang, Hong; Yang, Lin; Wu, Ruijuan; Zhang, Zhenxi

    2012-08-01

    Electrical instability easily induces a unidirectional conduction block, resulting in ventricular tachycardia (VT) or even fibrillation (VF). Cardiac memory affects dynamic electrical characteristics through previous pacing so that it makes the memory important in arrhythmia study. This paper investigates the impact of the rapid pacing duration on cellular excitability and its mechanism. Based on the canine endocardial single cell, a one-dimensional tissue model was developed. Simulations were realized with OpenMP parallel programming method. The results showed that with repetitive pacing, the cellular excitability became low while the conduction velocity decreased. Accumulation of intracellular [Ca2+]i and [Na+]i and depletion of [K+]i led to the shift of membrane current-voltage curves, changing the membrane resistance. Excitability determined by the resistance at the large width of stimulus pulse, therefore, it suggested that [Ca2+]i and [K+]i-induced memory formed the ionic substrates for the alteration of excitability.

  9. Cardiac tissue structure. Electric field interactions in polarizing the heart: 3D computer models and applications

    Science.gov (United States)

    Entcheva, Emilia

    1998-11-01

    The goal of this research is to investigate the interactions between the cardiac tissue structure and applied electric fields in producing complex polarization patterns. It is hypothesized that the response of the heart in the conditions of strong electric shocks, as those applied in defibrillation, is dominated by mechanisms involving the cardiac muscle structure perceived as a continuum. Analysis is carried out in three-dimensional models of the heart with detailed fiber architecture. Shock-induced transmembrane potentials are calculated using the bidomain model in its finite element implementation. The major new findings of this study can be summarized as follows: (1) The mechanisms of polarization due to cardiac fiber curvature and fiber rotation are elucidated in three-dimensional ellipsoidal hearts of variable geometry; (2) Results are presented showing that the axis of stimulation and the polarization axis on a whole heart level might differ significantly due to geometric and anisotropic factors; (3) Virtual electrode patterns are demonstrated numerically inside the ventricular wall in internal defibrillation conditions. The role of the tissue-bath interface in shaping the shock-induced polarization is revealed; (4) The generation of 3D phase singularity scrolls by shock-induced intramural virtual electrode patterns is proposed as evidence for a possible new mechanism for the failure to defibrillate. The results of this study emphasize the role of unequal anisotropy in the intra- and extracellular domains, as well as the salient fiber architecture characteristics, such as curvature and transmural rotation, in polarizing the myocardium. Experimental support of the above findings was actively sought and found in recent optical mapping studies using voltage-sensitive dyes. If validated in vivo, these findings would significantly enrich the prevailing concepts about the mechanisms of stimulation and defibrillation of the heart.

  10. Interplay between cardiac function and heart development.

    Science.gov (United States)

    Andrés-Delgado, Laura; Mercader, Nadia

    2016-07-01

    Mechanotransduction refers to the conversion of mechanical forces into biochemical or electrical signals that initiate structural and functional remodeling in cells and tissues. The heart is a kinetic organ whose form changes considerably during development and disease. This requires cardiomyocytes to be mechanically durable and able to mount coordinated responses to a variety of environmental signals on different time scales, including cardiac pressure loading and electrical and hemodynamic forces. During physiological growth, myocytes, endocardial and epicardial cells have to adaptively remodel to these mechanical forces. Here we review some of the recent advances in the understanding of how mechanical forces influence cardiac development, with a focus on fluid flow forces. This article is part of a Special Issue entitled: Cardiomyocyte Biology: Integration of Developmental and Environmental Cues in the Heart edited by Marcus Schaub and Hughes Abriel.

  11. Effects of Electric Stimulations Applied during Absolute Refractory Period on Cardiac Function of Rabbits with Heart Failure

    Institute of Scientific and Technical Information of China (English)

    张海柱; 崔长琮; 胡大一

    2010-01-01

    The effects of electric currents applied during absolute refractory period(ARP) on the cardiac function of rabbits with heart failure due to myocardial infarction(MI),and the safety of this method were investigated.Thirty rabbits were randomly assigned equally to 3 groups:sham-operated group,LV-anterior wall cardiac contractility modulation(LV-CCM) group,and septum-CCM(S-CCM) group.A thoracotomy was performed on all the rabbits.Electric pulses were delivered during the ARP on the anterior wall of left ventr...

  12. Effect of Twisted Fiber Anisotropy in Cardiac Tissue on Ablation with Pulsed Electric Fields

    Science.gov (United States)

    Xie, Fei; Zemlin, Christian W.

    2016-01-01

    Background Ablation of cardiac tissue with pulsed electric fields is a promising alternative to current thermal ablation methods, and it critically depends on the electric field distribution in the heart. Methods We developed a model that incorporates the twisted anisotropy of cardiac tissue and computed the electric field distribution in the tissue. We also performed experiments in rabbit ventricles to validate our model. We find that the model agrees well with the experimentally determined ablation volume if we assume that all tissue that is exposed to a field greater than 3 kV/cm is ablated. In our numerical analysis, we considered how tissue thickness, degree of anisotropy, and electrode configuration affect the geometry of the ablated volume. We considered two electrode configurations: two parallel needles inserted into the myocardium (“penetrating needles” configuration) and one circular electrode each on epi- and endocardium, opposing each other (“epi-endo” configuration). Results For thick tissues (10 mm) and moderate anisotropy ratio (a = 2), we find that the geometry of the ablated volume is almost unaffected by twisted anisotropy, i.e. it is approximately translationally symmetric from epi- to endocardium, for both electrode configurations. Higher anisotropy ratio (a = 10) leads to substantial variation in ablation width across the wall; these variations were more pronounced for the penetrating needle configuration than for the epi-endo configuration. For thinner tissues (4 mm, typical for human atria) and higher anisotropy ratio (a = 10), the epi-endo configuration yielded approximately translationally symmetric ablation volumes, while the penetrating electrodes configuration was much more sensitive to fiber twist. Conclusions These results suggest that the epi-endo configuration will be reliable for ablation of atrial fibrillation, independently of fiber orientation, while the penetrating electrode configuration may experience problems when the

  13. Cardiac Mean Electrical Axis in Thoroughbreds—Standardization by the Dubois Lead Positioning System

    Science.gov (United States)

    da Costa, Cássia Fré; Samesima, Nelson; Pastore, Carlos Alberto

    2017-01-01

    Background Different methodologies for electrocardiographic acquisition in horses have been used since the first ECG recordings in equines were reported early in the last century. This study aimed to determine the best ECG electrodes positioning method and the most reliable calculation of mean cardiac axis (MEA) in equines. Materials and Methods We evaluated the electrocardiographic profile of 53 clinically healthy Thoroughbreds, 38 males and 15 females, with ages ranging 2–7 years old, all reared at the São Paulo Jockey Club, in Brazil. Two ECG tracings were recorded from each animal, one using the Dubois lead positioning system, the second using the base-apex method. QRS complex amplitudes were analyzed to obtain MEA values in the frontal plane for each of the two electrode positioning methods mentioned above, using two calculation approaches, the first by Tilley tables and the second by trigonometric calculation. Results were compared between the two methods. Results There was significant difference in cardiac axis values: MEA obtained by the Tilley tables was +135.1° ± 90.9° vs. -81.1° ± 3.6° (p<0.0001), and by trigonometric calculation it was -15.0° ± 11.3° vs. -79.9° ± 7.4° (p<0.0001), base-apex and Dubois, respectively. Furthermore, Dubois method presented small range of variation without statistical or clinical difference by either calculation mode, while there was a wide variation in the base-apex method. Conclusion Dubois improved centralization of the Thoroughbreds' hearts, engendering what seems to be the real frontal plane. By either calculation mode, it was the most reliable methodology to obtain cardiac mean electrical axis in equines. PMID:28095442

  14. Effects of muscle electrical stimulation on peak VO2 in cardiac transplant patients.

    Science.gov (United States)

    Vaquero, A F; Chicharro, J L; Gil, L; Ruiz, M P; Sánchez, V; Lucía, A; Urrea, S; Gómez, M A

    1998-07-01

    Peak oxygen consumption (peak VO2) has become a critical component in the evaluation of heart transplant recipients (HTR). In these patients, peak VO2 remains low after cardiac transplantation mainly because of persisting peripheral limitations in the working muscles. Muscular electrical stimulation, on the other hand, has been shown to enhance the oxidative capacity of healthy muscle. It was the purpose of our investigation to study the effects of ES on the peak VO2 of HTR. Fourteen (11 males and 3 females) HTR (age: 57+/-7yr, mean +/- SD; height: 163+/-7 cm, weight: 70.5+/-8.6 kg) were selected as subjects and each of them was randomly assigned to one of two groups: (a) group EXP (n = 7), receiving electrical stimulation on both quadriceps muscles during a period of 8 weeks, and (b) group CONT (n = 7), not receiving electrical stimulation. Before (PRE) and after (POST) the aforementioned 8-week period, respectively, all the subjects performed a cardiopulmonary exercise test (ramp protocol) on a cycle ergometer for peak VO2 determination. PRE values of peak VO2 were similar in both groups (17.1+/-2.0 vs 16.9+/-3.8ml x kg(-1) x min(-1) in EXP and CONT, respectively). However, peak values of VO2 significantly increased in EXP (p < 0.05) after the period of electrical stimulation (POST peak VO2: 18.7+/-2.0ml x kg(-1)), whereas no change was observed in CONT (POST peak VO2: 16.2+/-3.2 ml x kg(-1) x min(-1)). In conclusion, electrical stimulation could therefore be used to improve the functional capacity of HTR, and might be included in the rehabilitation programs of this population group.

  15. Simulation method for cardiac stroke volume estimation by intracardiac electrical impedance measurement.

    Science.gov (United States)

    Barak, C; Leviatan, Y; Inbar, G F; Hoekstein, K N

    1992-09-01

    Using the electrical impedance measurement technique to investigate stroke volume estimation, three models of the ventricle were simulated. A four-electrode impedance catheter was used; two electrodes to set up an electric field in the model and the other two to measure the potential difference. A new approach, itself an application of the quasi-static case of a method used to solve electromagnetic field problems, was used to solve the electric field in the model. The behaviour of the estimation is examined with respect to the electrode configuration on the catheter and to catheter location with respect to the ventricle walls. Cardiac stroke volume estimation was found to be robust to catheter location generating a 10 per cent error for an offset of 40 per cent of the catheter from the chamber axis and rotation of 20 degrees with respect to the axis. The electrode configuration has a dominant effect on the sensitivity and accuracy of the estimation. Certain configurations gave high accuracy, whereas in others high sensitivity was found with lower accuracy. This led to the conclusion that the electrode configuration should be carefully chosen according to the desired criteria.

  16. THE EFFICACY OF MELDONIUM IN REDUCTION OF CARDIAC ELECTRICAL INSTABILITY IN PATIENTS WITH ISCHEMIC STROKE

    Directory of Open Access Journals (Sweden)

    A. A. Abdullaev

    2015-09-01

    Full Text Available Aim. To study meldonium effect in the combination therapy for ventricular repolarization disorders and cardiac electrical instability in patients with ischemic stroke.Material and methods. Patients (n=46 with acute phase of ischemic stroke were included in a randomized, open-label, uncontrolled study. Patients were randomized into two groups. Group 1 patients (n=25 had been receiving meldonium (Mildronate;Grindex,Latvia;Pharmstandard,Russia, 1.0 g/day intravenously once daily, as a part of standard therapy for 10 days since admission to the hospital. Group 2 patients (n=21 had standard therapy alone. A standart 12-lead ECG, ventricular late potentials (VLP, 24-hour Holter monitoring, troponin test were performed at the baseline and after 10 days.Results. Patients of the group 1 as compared to the group 2 demonstrated more significant positive effect on the clinical condition of patients with ischemic stroke, ventricular repolarization, reduction of frequency (from 3.7±0.5 to 2.1±0.4; p<0.05 and duration (from 6.6±1, 3 to 4.0±1.1 min; p<0.05 of painless myocardial ischemia episodes and VLP (from 48 to 32%.Conclusion. Adding meldonium to standard therapy in patients with acute phase of ischemic stroke can have a positive effect on the clinical condition, repolarization disorders on ECG, frequency of VLP and episodes of painless myocardial ischemia detection. This may have a positive effect on the electrical stability and prevention of cardiac arrhythmias. 

  17. THE EFFICACY OF MELDONIUM IN REDUCTION OF CARDIAC ELECTRICAL INSTABILITY IN PATIENTS WITH ISCHEMIC STROKE

    Directory of Open Access Journals (Sweden)

    A. A. Abdullaev

    2014-01-01

    Full Text Available Aim. To study meldonium effect in the combination therapy for ventricular repolarization disorders and cardiac electrical instability in patients with ischemic stroke.Material and methods. Patients (n=46 with acute phase of ischemic stroke were included in a randomized, open-label, uncontrolled study. Patients were randomized into two groups. Group 1 patients (n=25 had been receiving meldonium (Mildronate;Grindex,Latvia;Pharmstandard,Russia, 1.0 g/day intravenously once daily, as a part of standard therapy for 10 days since admission to the hospital. Group 2 patients (n=21 had standard therapy alone. A standart 12-lead ECG, ventricular late potentials (VLP, 24-hour Holter monitoring, troponin test were performed at the baseline and after 10 days.Results. Patients of the group 1 as compared to the group 2 demonstrated more significant positive effect on the clinical condition of patients with ischemic stroke, ventricular repolarization, reduction of frequency (from 3.7±0.5 to 2.1±0.4; p<0.05 and duration (from 6.6±1, 3 to 4.0±1.1 min; p<0.05 of painless myocardial ischemia episodes and VLP (from 48 to 32%.Conclusion. Adding meldonium to standard therapy in patients with acute phase of ischemic stroke can have a positive effect on the clinical condition, repolarization disorders on ECG, frequency of VLP and episodes of painless myocardial ischemia detection. This may have a positive effect on the electrical stability and prevention of cardiac arrhythmias. 

  18. Electrical stimulation directs engineered cardiac tissue to an age-matched native phenotype

    Directory of Open Access Journals (Sweden)

    Richard A Lasher

    2012-12-01

    Full Text Available Quantifying structural features of native myocardium in engineered tissue is essential for creating functional tissue that can serve as a surrogate for in vitro testing or the eventual replacement of diseased or injured myocardium. We applied three-dimensional confocal imaging and image analysis to quantitatively describe the features of native and engineered cardiac tissue. Quantitative analysis methods were developed and applied to test the hypothesis that environmental cues direct engineered tissue toward a phenotype resembling that of age-matched native myocardium. The analytical approach was applied to engineered cardiac tissue with and without the application of electrical stimulation as well as to age-matched and adult native tissue. Individual myocytes were segmented from confocal image stacks and assigned a coordinate system from which measures of cell geometry and connexin-43 spatial distribution were calculated. The data were collected from 9 nonstimulated and 12 electrically stimulated engineered tissue constructs and 5 postnatal day 12 and 7 adult hearts. The myocyte volume fraction was nearly double in stimulated engineered tissue compared to nonstimulated engineered tissue (0.34 ± 0.14 vs 0.18 ± 0.06 but less than half of the native postnatal day 12 (0.90 ± 0.06 and adult (0.91 ± 0.04 myocardium. The myocytes under electrical stimulation were more elongated compared to nonstimulated myocytes and exhibited similar lengths, widths, and heights as in age-matched myocardium. Furthermore, the percentage of connexin-43-positive membrane staining was similar in the electrically stimulated, postnatal day 12, and adult myocytes, whereas it was significantly lower in the nonstimulated myocytes. Connexin-43 was found to be primarily located at cell ends for adult myocytes and irregularly but densely clustered over the membranes of nonstimulated, stimulated, and postnatal day 12 myocytes. These findings support our hypothesis and reveal

  19. 体外心脏震波治疗改善心肌梗死后心室重塑研究进展%Research Progress of Extracorporeal Cardiac Shock Wave Therapy Improving Ventricular Remodeling after Myocardial Infarction

    Institute of Scientific and Technical Information of China (English)

    陶四明; 王钰; 郭涛

    2009-01-01

    Ventricular remodeling after myocardial infarction is a pathophysiological process. It is one of the most important risk factors for long-term mortality. Some research has found that many factors participate in, and accelerate the occurance of, ventricular remodeling after myocardial infarction. It was discovered that low-energy extracorporeal shock wave therapy can improve and regulate the function of myocardium during necrosis and can reconstruct the collagen metabolic process. This article reviews the mechanism of ventricular remodeling after myocardial infarction, explains the biological effect of shock wave, and the status of clinical application of extracorporeal cardiac shock wave therapy with the intent of improving ventricular remodeling after myocardial infarction.%急性心肌梗死后左室重构是临床上常见的进行性发展的病理生理过程,是心肌梗死远期心脏性死亡最重要危险因素之一.研究发现有多重因素参与相互促进,共同维持心肌梗死后心室重塑的发生发展.研究发现低能量的体外震波治疗有多项机制调节参与改善和恢复坏死区休眠心肌细胞功能,重新建立胶原代谢平衡,终止和缓解心室重塑发展.现综述心肌梗死后心室重塑发生机制;阐述震波治疗的生物效应及体外心脏震波治疗改善心肌梗死后心室重塑的潜在机制及研究现状.

  20. Role of the basement membrane in regulation of cardiac electrical properties.

    Science.gov (United States)

    Yang, Huaxiao; Borg, Thomas K; Wang, Zhonghai; Ma, Zhen; Gao, Bruce Z

    2014-06-01

    In the heart muscle, each adult cardiomyocyte is enclosed by a basement membrane (BM). This innermost extracellular matrix is a layered assembly of laminin, collagen IV, glycoproteins, and proteoglycans. In this study, the role of the BM network in regulation of the electrical properties of neonatal cardiomyocytes (NCMs) cultured on an aligned collagen I gel was investigated using a multielectrode array (MEA). A laminin antibody was added to the culture medium for 48-120 h to conjugate newly secreted laminin. Then, morphology of the NCMs on an MEA was monitored using a phase contrast microscope, and the BM network that was immunocytostained for laminin was imaged using a fluorescence microscope. When the BM laminin was absent in this culture model, dramatic changes in NCM morphology were observed. Simultaneously, the MEA-recorded cardiac field potential showed changes compared to that from the control groups: The period of contraction shortened to 1/2 of that from the control groups, and the waveform of the calcium influx shifted from a flat plateau to a peak-like waveform, indicating that the electrical properties of the NCMs were closely related to the components and distribution of the BM network.

  1. A generalized finite difference method for modeling cardiac electrical activation on arbitrary, irregular computational meshes.

    Science.gov (United States)

    Trew, Mark L; Smaill, Bruce H; Bullivant, David P; Hunter, Peter J; Pullan, Andrew J

    2005-12-01

    A generalized finite difference (GFD) method is presented that can be used to solve the bi-domain equations modeling cardiac electrical activity. Classical finite difference methods have been applied by many researchers to the bi-domain equations. However, these methods suffer from the limitation of requiring computational meshes that are structured and orthogonal. Finite element or finite volume methods enable the bi-domain equations to be solved on unstructured meshes, although implementations of such methods do not always cater for meshes with varying element topology. The GFD method solves the bi-domain equations on arbitrary and irregular computational meshes without any need to specify element basis functions. The method is useful as it can be easily applied to activation problems using existing meshes that have originally been created for use by finite element or finite difference methods. In addition, the GFD method employs an innovative approach to enforcing nodal and non-nodal boundary conditions. The GFD method performs effectively for a range of two and three-dimensional test problems and when computing bi-domain electrical activation moving through a fully anisotropic three-dimensional model of canine ventricles.

  2. Preservation of cardiac function by prolonged action potentials in mice deficient of KChIP2

    DEFF Research Database (Denmark)

    Grubb, Søren Jahn; Aistrup, Gary L; Koivumäki, Jussi T

    2015-01-01

    Inherited ion channelopathies and electrical remodeling in heart disease alter the cardiac action potential with important consequences for excitation-contraction coupling. Potassium channel-interacting protein 2 (KChIP2) is reduced in heart failure and interacts under physiological conditions...

  3. Cardiac structure and function, remodeling, and clinical outcomes among patients with diabetes after myocardial infarction complicated by left ventricular systolic dysfunction, heart failure, or both

    DEFF Research Database (Denmark)

    Shah, Amil M; Hung, Chung-Lieh; Shin, Sung Hee;

    2011-01-01

    The mechanisms responsible for the increased risk of heart failure (HF) post-myocardial infarction (MI) may differ between patients with versus without diabetes. We hypothesized that after high-risk MI, patients with diabetes would demonstrate patterns of remodeling that are suggestive of reduced...

  4. Myocardial area at risk after ST-elevation myocardial infarction measured with the late gadolinium enhancement after scar remodeling and T2-weighted cardiac magnetic resonance imaging

    DEFF Research Database (Denmark)

    Lønborg, Jacob; Engstrøm, Thomas; Mathiasen, Anders B;

    2011-01-01

    To evaluate the myocardial area at risk (AAR) measured by the endocardial surface area (ESA) method on late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) when applied after scar remodeling (3 months after index infarction) compared to T2-weighted CMR imaging. One hundred...

  5. Myocardial area at risk after ST-elevation myocardial infarction measured with the late gadolinium enhancement after scar remodeling and T2-weighted cardiac magnetic resonance imaging

    DEFF Research Database (Denmark)

    Lønborg, Jacob; Engstrøm, Thomas; Mathiasen, Anders B;

    2012-01-01

    To evaluate the myocardial area at risk (AAR) measured by the endocardial surface area (ESA) method on late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) when applied after scar remodeling (3 months after index infarction) compared to T2-weighted CMR imaging. One hundred...

  6. Modeling the response of normal and ischemic cardiac tissue to electrical stimulation

    Science.gov (United States)

    Kandel, Sunil Mani

    Heart disease, the leading cause of death worldwide, is often caused by ventricular fibrillation. A common treatment for this lethal arrhythmia is defibrillation: a strong electrical shock that resets the heart to its normal rhythm. To design better defibrillators, we need a better understanding of both fibrillation and defibrillation. Fundamental mysteries remain regarding the mechanism of how the heart responds to a shock, particularly anodal shocks and the resultant hyperpolarization. Virtual anodes play critical roles in defibrillation, and one cannot build better defibrillators until these mechanisms are understood. We are using mathematical modeling to numerically simulate observed phenomena, and are exploring fundamental mechanisms responsible for the heart's electrical behavior. Such simulations clarify mechanisms and identify key parameters. We investigate how systolic tissue responds to an anodal shock and how refractory tissue reacts to hyperpolarization by studying the dip in the anodal strength-interval curve. This dip is due to electrotonic interaction between regions of depolarization and hyperpolarization following a shock. The dominance of the electrotonic mechanism over calcium interactions implies the importance of the spatial distribution of virtual electrodes. We also investigate the response of localized ischemic tissue to an anodal shock by modeling a regional elevation of extracellular potassium concentration. This heterogeneity leads to action potential instability, 2:1 conduction block (alternans), and reflection-like reentry at the boarder of the normal and ischemic regions. This kind of reflection (reentry) occurs due to the delay between proximal and distal segments to re-excite the proximal segment. Our numerical simulations are based on the bidomain model, the state-of-the-art mathematical description of how cardiac tissue responds to shocks. The dynamic LuoRudy model describes the active properties of the membrane. To model ischemia

  7. Abnormal sodium current properties contribute to cardiac electrical and contractile dysfunction in a mouse model of myotonic dystrophy type 1.

    Science.gov (United States)

    Algalarrondo, Vincent; Wahbi, Karim; Sebag, Frédéric; Gourdon, Geneviève; Beldjord, Chérif; Azibi, Kamel; Balse, Elise; Coulombe, Alain; Fischmeister, Rodolphe; Eymard, Bruno; Duboc, Denis; Hatem, Stéphane N

    2015-04-01

    Myotonic dystrophy type 1 (DM1) is the most common neuromuscular disorder and is associated with cardiac conduction defects. However, the mechanisms of cardiac arrhythmias in DM1 are unknown. We tested the hypothesis that abnormalities in the cardiac sodium current (INa) are involved, and used a transgenic mouse model reproducing the expression of triplet expansion observed in DM1 (DMSXL mouse). The injection of the class-I antiarrhythmic agent flecainide induced prominent conduction abnormalities and significantly lowered the radial tissular velocities and strain rate in DMSXL mice compared to WT. These abnormalities were more pronounced in 8-month-old mice than in 3-month-old mice. Ventricular action potentials recorded by standard glass microelectrode technique exhibited a lower maximum upstroke velocity [dV/dt](max) in DMSXL. This decreased [dV/dt](max) was associated with a 1.7 fold faster inactivation of INa in DMSXL myocytes measured by the whole-cell patch-clamp technique. Finally in the DMSXL mouse, no mutation in the Scn5a gene was detected and neither cardiac fibrosis nor abnormalities of expression of the sodium channel protein were observed. Therefore, alterations in the sodium current markedly contributed to electrical conduction block in DM1. This result should guide pharmaceutical and clinical research toward better therapy for the cardiac arrhythmias associated with DM1.

  8. Protein kinase C pathway on cardiac sympathetic nerve neuroplasticity and myocardial interstitial remodeling%心脏交感神经和心肌间质重塑的共同通路——蛋白激酶C途径

    Institute of Scientific and Technical Information of China (English)

    李贺; 周欣; 王坷; 赵丽霞; 王志宏; 李玉明

    2011-01-01

    Cardiac sympathetic nerve and myocardial interstitium play important roles for preservation of heart function. Different extent of the interstitial remodeling and neuroplasticity commonly occur in many kinds of cardiovascular diseases. The abnormalities interact and contribute to progression and worsening of the diseases. There is accumulating evidence suggesting that protein kinase C activation as a regulator involves in and mediates interaction between the neuroplasticity and remodeling under such conditions, which plays a critical role in the nerve dysfunction and myocardial fibrosis.%心脏交感神经和心肌间质对维持正常心功能有重要作用.心血管患病时,两者均发生不同程度的重塑,并互相影响,这些变化对疾病进展发挥重要影响.研究证据显示,两者间的相互作用可能通过蛋白激酶C介导,对交感神经功能异常和心肌纤维化都发挥重要作用.

  9. Development of Electrically Conductive Double-Network Hydrogels via One-Step Facile Strategy for Cardiac Tissue Engineering.

    Science.gov (United States)

    Yang, Boguang; Yao, Fanglian; Hao, Tong; Fang, Wancai; Ye, Lei; Zhang, Yabin; Wang, Yan; Li, Junjie; Wang, Changyong

    2016-02-18

    Cardiac tissue engineering is an effective method to treat the myocardial infarction. However, the lack of electrical conductivity of biomaterials limits their applications. In this work, a homogeneous electronically conductive double network (HEDN) hydrogel via one-step facile strategy is developed, consisting of a rigid/hydrophobic/conductive network of chemical crosslinked poly(thiophene-3-acetic acid) (PTAA) and a flexible/hydrophilic/biocompatible network of photo-crosslinking methacrylated aminated gelatin (MAAG). Results suggest that the swelling, mechanical, and conductive properties of HEDN hydrogel can be modulated via adjusting the ratio of PTAA network to MAAG network. HEDN hydrogel has Young's moduli ranging from 22.7 to 493.1 kPa, and its conductivity (≈10(-4) S cm(-1)) falls in the range of reported conductivities for native myocardium tissue. To assess their biological activity, the brown adipose-derived stem cells (BADSCs) are seeded on the surface of HEDN hydrogel with or without electrical stimulation. Our data show that the HEDN hydrogel can support the survival and proliferation of BADSCs, and that it can improve the cardiac differentiation efficiency of BADSCs and upregulate the expression of connexin 43. Moreover, electrical stimulation can further improve this effect. Overall, it is concluded that the HEDN hydrogel may represent an ideal scaffold for cardiac tissue engineering.

  10. Evidence of structural remodeling in the dyssynchronous failing heart.

    Science.gov (United States)

    Helm, Patrick A; Younes, Laurent; Beg, Mirza F; Ennis, Daniel B; Leclercq, Christophe; Faris, Owen P; McVeigh, Elliot; Kass, David; Miller, Michael I; Winslow, Raimond L

    2006-01-01

    Ventricular remodeling of both geometry and fiber structure is a prominent feature of several cardiac pathologies. Advances in MRI and analytical methods now make it possible to measure changes of cardiac geometry, fiber, and sheet orientation at high spatial resolution. In this report, we use diffusion tensor imaging to measure the geometry, fiber, and sheet architecture of eight normal and five dyssynchronous failing canine hearts, which were explanted and fixed in an unloaded state. We apply novel computational methods to identify statistically significant changes of cardiac anatomic structure in the failing and control heart populations. The results demonstrate significant regional differences in geometric remodeling in the dyssynchronous failing heart versus control. Ventricular chamber dilatation and reduction in wall thickness in septal and some posterior and anterior regions are observed. Primary fiber orientation showed no significant change. However, this result coupled with the local wall thinning in the septum implies an altered transmural fiber gradient. Further, we observe that orientation of laminar sheets become more vertical in the early-activated septum, with no significant change of sheet orientation in the late-activated lateral wall. Measured changes in both fiber gradient and sheet structure will affect both the heterogeneity of passive myocardial properties as well as electrical activation of the ventricles.

  11. SR-targeted CaMKII inhibition improves SR Ca2+ handling, but accelerates cardiac remodeling in mice overexpressing CaMKIIδC

    OpenAIRE

    Huke, Sabine; DeSantiago, Jaime; Kaetzel, Marcia A.; Mishra, Shikha; Brown, Joan H.; Dedman, John R.; Bers, Donald M.

    2010-01-01

    Cardiac myocyte overexpression of CaMKIIδC leads to cardiac hypertrophy and heart failure (HF) possibly caused by altered myocyte Ca2+ handling. A central defect might be the marked CaMKII-induced increase in diastolic sarcoplasmic reticulum (SR) Ca2+ leak which decreases SR Ca2+ load and Ca2+ transient amplitude. We hypothesized that inhibition of CaMKII near the SR membrane would decrease the leak, improve Ca2+ handling and prevent the development of contractile dysfunction and HF. To test ...

  12. Material-based engineering strategies for cardiac regeneration.

    Science.gov (United States)

    Marion, Mieke H van; Bax, Noortje A M; Spreeuwel, Ariane C C van; van der Schaft, Daisy W J; Bouten, Carlijn V C

    2014-01-01

    Cardiac tissue is composed of muscle and non-muscle cells, surrounded by extracellular matrix (ECM) and spatially organized into a complex three-dimensional (3D) architecture to allow for coordinated contraction and electrical pulse propagation. Despite emerging evidence for cardiomyocyte turnover in mammalian hearts, the regenerative capacity of human cardiac tissue is insufficient to recover from damage, e.g. resulting from myocardial infarction (MI). Instead, the heart 'repairs' lost or injured tissue by ongoing synthesis and remodeling of scar tissue. Conventional therapies and timely (stem) cell delivery to the injured tissue markedly improve short-term function and remodeling, but do not attenuate later stage adverse remodeling, leading to functional deterioration and eventually failure of the heart. Material-based therapies have been successfully used to mechanically support and constrain the post-MI failing heart, preventing it from further remodeling and dilation. When designed to deliver the right microenvironment for endogenous or exogenous cells, as well as the mechanical and topological cues to guide neo-tissue formation, material-based therapies may even reverse remodeling and boost cardiac regeneration. This paper reviews the up-to-date status of material-based cardiac regeneration with special emphasis on 1) the use of bare biomaterials to deliver passive constraints that unload the heart, 2) the use of materials and cells to create engineered cardiac constructs for replacement, support, or regeneration of damaged myocardium, and 3) the development of bio-inspired and bioactive materials that aim to enhance the endogenous regenerative capacity of the heart. As the therapies should function in the infarcted heart, the damaged host environment and engineered in vitro test systems that mimic this environment, are reviewed as well.

  13. [Electrical cardioversion in the treatment of cardiac arrhythmias during pregnancy--case report and review of literature].

    Science.gov (United States)

    Gałczyński, Krzysztof; Marciniak, Beata; Kudlicki, Janusz; Kimber-Trojnar, Zaneta; Leszczyńska-Gorzelak, Bozena; Oleszczukz, Jan

    2013-10-01

    The incidence of cardiac arrhythmias is estimated et 1.2 per 1000 pregnancies, usually in the third trimester and 50% of them are asymptomatic. They may appear for the first time in pregnancy or have a recurring character An important risk factor related to their appearance is the presence of structural heart disease, which complicates arrhythmias may require urgent, life-saving procedures. External electrical cardioversion is associated with the application of certain amount of energy via two electrodes placed on the thorax. It is used to treat hemodynamically unstable supraventricular tachycardias, including atrial fibrillation and atrial flutter Also in hemodynamically stable patients in whom drug therapy was ineffective elective electrical cardioversion can be use to convert cardiac arrhythmia to sinus rhythm. We present a case of a 33 years old patient with congenital heart disease surgically corrected in childhood who had first incident of atrial flutter in pregnancy. Arrhytmia occured in 26th week of gestation. The patient was hemodynamically stable and did not approve electrical cardioversion as a method of treatment therefore pharmacotherapy was started. Heart rate was controled with metoprolol and digoxin, warfarin was used to anticoagulation. Calcium and potassium were also given. Described therapy did not convert atrial flutter to sinus rhythm therefore in 33rd week of gestation after patient's approval electrical cardioversion was performed. Before cardioversion transesophageal echocardiogram was made to exclude the presence of thrombus inside atria. Energy of 50J was applied and sinus rhythm was restored. Cardiotocography during and after cardioversion did not show any significant fetal heart rate changes. Further pregnancy and puerperium were uneventful. Case report and review of the literature about cardiac arrhytmias and methods of its treatment especially in pregnant women. Analysis of medical documentation of the patient treated in the Department

  14. Remodeling in the ischemic heart: the stepwise progression for heart

    Directory of Open Access Journals (Sweden)

    J.G. Mill

    2011-09-01

    Full Text Available Abstract Coronary artery disease is the leading cause of death in the developed world and in developing countries. Acute mortality from acute myocardial infarction (MI has decreased in the last decades. However, the incidence of heart failure (HF in patients with healed infarcted areas is increasing. Therefore, HF prevention is a major challenge to the health system in order to reduce healthcare costs and to provide a better quality of life. Animal models of ischemia and infarction have been essential in providing precise information regarding cardiac remodeling. Several of these changes are maladaptive, and they progressively lead to ventricular dilatation and predispose to the development of arrhythmias, HF and death. These events depend on cell death due to necrosis and apoptosis and on activation of the inflammatory response soon after MI. Systemic and local neurohumoral activation has also been associated with maladaptive cardiac remodeling, predisposing to HF. In this review, we provide a timely description of the cardiovascular alterations that occur after MI at the cellular, neurohumoral and electrical level and discuss the repercussions of these alterations on electrical, mechanical and structural dysfunction of the heart. We also identify several areas where insufficient knowledge limits the adoption of better strategies to prevent HF development in chronically infarcted individuals.

  15. Hormones and sex differences: changes in cardiac electrophysiology with pregnancy.

    Science.gov (United States)

    Bett, Glenna C L

    2016-05-01

    Disruption of cardiac electrical activity resulting in palpitations and syncope is often an early symptom of pregnancy. Pregnancy is a time of dramatic and dynamic physiological and hormonal changes during which numerous demands are placed on the heart. These changes result in electrical remodelling which can be detected as changes in the electrocardiogram (ECG). This gestational remodelling is a very under-researched area. There are no systematic large studies powered to determine changes in the ECG from pre-pregnancy, through gestation, and into the postpartum period. The large variability between patients and the dynamic nature of pregnancy hampers interpretation of smaller studies, but some facts are consistent. Gestational cardiac hypertrophy and a physical shift of the heart contribute to changes in the ECG. There are also electrical changes such as an increased heart rate and lengthening of the QT interval. There is an increased susceptibility to arrhythmias during pregnancy and the postpartum period. Some changes in the ECG are clearly the result of changes in ion channel expression and behaviour, but little is known about the ionic basis for this electrical remodelling. Most information comes from animal models, and implicates changes in the delayed-rectifier channels. However, it is likely that there are additional roles for sodium channels as well as changes in calcium homoeostasis. The changes in the electrical profile of the heart during pregnancy and the postpartum period have clear implications for the safety of pregnant women, but the field remains relatively undeveloped.

  16. Chromatin remodeling in cardiovascular development and physiology.

    Science.gov (United States)

    Han, Pei; Hang, Calvin T; Yang, Jin; Chang, Ching-Pin

    2011-02-04

    Chromatin regulation provides an important means for controlling cardiac gene expression under different physiological and pathological conditions. Processes that direct the development of normal embryonic hearts and pathology of stressed adult hearts may share general mechanisms that govern cardiac gene expression by chromatin-regulating factors. These common mechanisms may provide a framework for us to investigate the interactions among diverse chromatin remodelers/modifiers and various transcription factors in the fine regulation of gene expression, essential for all aspects of cardiovascular biology. Aberrant cardiac gene expression, triggered by a variety of pathological insults, can cause heart diseases in both animals and humans. The severity of cardiomyopathy and heart failure correlates strongly with abnormal cardiac gene expression. Therefore, controlling cardiac gene expression presents a promising approach to the treatment of human cardiomyopathy. This review focuses on the roles of ATP-dependent chromatin-remodeling factors and chromatin-modifying enzymes in the control of gene expression during cardiovascular development and disease.

  17. 先心病心脏重构患者血清血管紧张素转化酶2水平研究%The Serum Levels of Angiotensin-converting Enzyme2 in Patients of Congenital Heart Disease with Cardiac Remodeling

    Institute of Scientific and Technical Information of China (English)

    郭玥; 吕宁; 尹小龙

    2013-01-01

    目的 观察先心病(congenital heart disease,CHD)伴心脏重构(Cardiac remodeling)患者血管紧张素转化酶2 (angiotensin-convertirg enzyrre 2,ACE2)含量和活性的变化,探讨它们与心脏重构的关系.方法 收集被确诊为先心病的患者104例, (其中无心脏重构组80例,合并心脏重构组24例),正常对照组33例.抽取受试者静脉血,应用酶联免疫吸附法(ELISA)检测血清ACE2酶含量,用比色法检测ACE2酶活性的水平,所得实验数据使用SPSS统计软件进行分析.结果 (1)正常对照组、先心病无心脏重构组、先心病心脏重构组ACE2酶含量测定值分别为(15.79± 5.03) U/L、(18.85±6.46) U/L、(14.80±4.58) U/L.正常对照组与先心病无心脏重构组比较,ACE2含量差异有统计学意义(P<0.05);正常对照组与先心病心脏重构组比较,ACE2含量无差异(P>0.05);先心病无心脏重构组与心脏重构组比较,ACE2含量差异有统计学意义(P<0.01); (2)正常对照组、先心病无心脏重构组、先心病心脏重构组ACE2酶活性测定值分别为(1.75±0.82) U/L、(1.85±0.62) U/L、(158±0.52) U/L,3组间比较差异无统计学意义(P>0.05).结论 (1)先心病无心脏重构患者血清中的ACE2酶含量显著升高; (2)先心病无心脏重构患者与心脏重构患者血清中ACE2酶活性无变化.%Objective To observe the Angiotensin-converting enzyme2 (ACE2) protein contents and activity in the serum of patients with Congenital Heart Disease (CHD) combined with cardiac remodeling (CR) , and investigate the correlation of those with cardiac remodeling. Methods 104 patients with Congenital Heart Disease and 33 normal control patients were collected. The patients with congenital heart disease were divided into 80 cases of non-cardiac remodeling group, and 24 cases of cardiac remodeling group. The serum levels of ACE2 protein were detected by enzyme-linked immunosorbent assay ( ELISA) , ACE2 activity was detected by colorimetric

  18. Acceleration of cutaneous healing by electrical stimulation: degenerate electrical waveform down-regulates inflammation, up-regulates angiogenesis and advances remodeling in temporal punch biopsies in a human volunteer study.

    Science.gov (United States)

    Sebastian, Anil; Syed, Farhatullah; Perry, Donna; Balamurugan, Vinayagapriya; Colthurst, James; Chaudhry, Iskander H; Bayat, Ardeshir

    2011-11-01

    We previously demonstrated the beneficial effect of a novel electrical stimulation (ES) waveform, degenerate wave (DW) on skin fibroblasts, and now hypothesize that DW can enhance cutaneous wound healing in vivo. Therefore, a punch biopsy was taken from the upper arm of 20 volunteers on day 0 and repeated on day 14 (NSD14). A contralateral upper arm biopsy was taken on day 0 and treated with DW for 14 days prior to a repeat biopsy on day 14 (ESD14). A near-completed inflammatory stage of wound healing in ESD14, compared to NSD14 was demonstrated by up-regulation of interleukin-10 and vasoactive intestinal peptide using quantitative real time polymerase chain reaction and down-regulation of CD3 by immunohistochemistry (IHC) (p advanced remodeling phase.

  19. Effect of Shensong Yangxin Capsule on Cardiac Remodelling of Myocardial Infarction Mouse Model%参松养心胶囊对心肌梗死模型小鼠心脏重构的影响

    Institute of Scientific and Technical Information of China (English)

    向家培; 赵劲波; 王勇; 华晓芳; 黄浩; 雷玉华

    2016-01-01

    Objective To investigate the effect of Shensong Yangxin capsule on cardiac remodelling of myocardial infarction mouse model and the possible molecular mechanisms. Methods Adult male C57BL/6J mice were divided into sham operation group(n=10), model control group(n=20)and Shensong Yangxin group(n=20)according to random number table. Left anterior descending branch of coronary artery was ligated to establish myocardic infarction model in the model control group and Shensong Yangxin group. From the 2nd day after the surgery, Shensong Yangxin ( 400 mg . kg-1 ) was intragastrically administered, and the death rate of the mice was observed.Four weeks after the surgery, echocardiography was used to measure the cardiac function;myocardiac infarction area was detected by pathological staining;the expression levels of cardiac remodelling markers and extracellular matrix proteins were detected by RT-PCR. The possible molecular mechanisms were screened by Western blotting. Results As compared with the model control group, Shensong Yangxin significantly reduced the mortality after myocardial infarction in mice(P<0.05), as well as the myocardial infarct size(P<0.05).The mRNA expression levels of cardiac remodelling markers ANP, BNP, and β-MHC and the extracellular matrix proteins(collagenⅠ, collagen Ⅲ, CTGF, TGFβ) decreased significantly in the Shensong Yangxin group as compared with the model control group. Western blotting showed that Shensong Yangxin significantly decreased activation of smad3, and reduced expression level of smad4. Conclusion Shensong Yangxin attenuates cardiac remodelling after myocardial infarction and the mechanism may be related with blockage of smad signaling pathway.%目的:探讨参松养心胶囊对小鼠心肌梗死后心脏重构的影响及其可能的分子机制。方法 C57BL/6J小鼠按照随机数字表法分为假手术组( n=10),模型对照组( n=20)和参松养心组( n=20)。模型对照组和参松养心组采用冠状动

  20. The relationship between gap junctional remodeling and human atrial fibrillation

    Institute of Scientific and Technical Information of China (English)

    李大强; 冯义柏; 张会琴

    2004-01-01

    @@ Atrial fibrillation (AF) is currently the most common cardiac tachyarrhythmia in clinical practice. AF has a tendency to become more persistent over time. Progression of an underlying disease is one explanation. Another possible explanation is electrical, structural, and gap junctional remodeling of the atrium by repetitive induction of AF.1 The expression level and distribution of it have close relation with the conduction velocity of electrical activation in the atrium. The aim of the present study was to investigate the alternations of the expression and distribution of (connexin 40, Cx 40) and (connexin 43, Cx 43) in the right atrial appendages of the patients with AF by laser confocal scanning microscopy and Western blot technique.

  1. [Parameters of cardiac muscle repolarization on the electrocardiogram when changing anatomical and electric position of the heart].

    Science.gov (United States)

    Chaĭkovskiĭ, I A; Baum, O V; Popov, L A; Voloshin, V I; Budnik, N N; Frolov, Iu A; Kovalenko, A S

    2014-01-01

    While discussing the diagnostic value of the single channel electrocardiogram a set of theoretical considerations emerges inevitably, one of the most important among them is the question about dependence of the electrocardiogram parameters from the direction of electrical axis of heart. In other words, changes in what of electrocardiogram parameters are in fact liable to reflect pathological processes in myocardium, and what ones are determined by extracardiac factors, primarily by anatomic characteristics of patients. It is arguable that while analyzing electrocardiogram it is necessary to orient to such physiologically based informative indexes as ST segment displacement. Also, symmetry of the T wave shape is an important parameter which is independent of patients anatomic features. The results obtained are of interest for theoretical and applied aspects of the biophysics of the cardiac electric field.

  2. Electrical Properties of Isolated Cardiomyocytes in a Rat Model of Thiamine Deficiency

    Directory of Open Access Journals (Sweden)

    Artur Santos-Miranda

    2015-03-01

    Full Text Available In modern society, thiamine deficiency (TD remains an important medical condition linked to altered cardiac function. There have been contradictory reports about the impact of TD on heart physiology, especially in the context of cardiac excitability. In order to address this particular question, we used a TD rat model and patch-clamp technique to investigate the electrical properties of isolated cardiomyocytes from epicardium and endocardium. Neither cell type showed substantial differences on the action potential waveform and transient outward potassium current. Based on our results we can conclude that TD does not induce major electrical remodeling in isolated cardiac myocytes in either endocardium or epicardium cells.

  3. Atrial Electrophysiological Remodeling and Fibrillation in Heart Failure

    Science.gov (United States)

    Pandit, Sandeep V.; Workman, Antony J.

    2016-01-01

    Heart failure (HF) causes complex, chronic changes in atrial structure and function, which can cause substantial electrophysiological remodeling and predispose the individual to atrial fibrillation (AF). Pharmacological treatments for preventing AF in patients with HF are limited. Improved understanding of the atrial electrical and ionic/molecular mechanisms that promote AF in these patients could lead to the identification of novel therapeutic targets. Animal models of HF have identified numerous changes in atrial ion currents, intracellular calcium handling, action potential waveform and conduction, as well as expression and signaling of associated proteins. These studies have shown that the pattern of electrophysiological remodeling likely depends on the duration of HF, the underlying cardiac pathology, and the species studied. In atrial myocytes and tissues obtained from patients with HF or left ventricular systolic dysfunction, the data on changes in ion currents and action potentials are largely equivocal, probably owing mainly to difficulties in controlling for the confounding influences of multiple variables, such as patient’s age, sex, disease history, and drug treatments, as well as the technical challenges in obtaining such data. In this review, we provide a summary and comparison of the main animal and human electrophysiological studies to date, with the aim of highlighting the consistencies in some of the remodeling patterns, as well as identifying areas of contention and gaps in the knowledge, which warrant further investigation. PMID:27812293

  4. Chromatin remodeling in cardiovascular development and physiology

    OpenAIRE

    Han, Pei; Hang, Calvin T.; Yang, Jin; Chang, Ching-Pin

    2011-01-01

    Chromatin regulation provides an important means of controlling cardiac gene expression under different physiological and pathological conditions. Processes that direct the development of normal embryonic hearts and pathology of stressed adult hearts may share general mechanisms that govern cardiac gene expression by chromatin-regulating factors. These common mechanisms may provide a framework for us to investigate the interactions among diverse chromatin remodelers/modifiers and various tran...

  5. Raise the Floor When Remodeling Science Labs

    Science.gov (United States)

    Nation's Schools, 1972

    1972-01-01

    A new remodeling idea adopts the concept of raised floor covering gas, water, electrical, and drain lines. The accessible floor has removable panels set into an adjustable support frame 24 inches above a concrete subfloor. (Author)

  6. PARP-inhibitor treatment prevents hypertension induced cardiac remodeling by favorable modulation of heat shock proteins, Akt-1/GSK-3β and several PKC isoforms.

    Directory of Open Access Journals (Sweden)

    Laszlo Deres

    Full Text Available Spontaneously hypertensive rat (SHR is a suitable model for studies of the complications of hypertension. It is known that activation of poly(ADP-ribose polymerase enzyme (PARP plays an important role in the development of postinfarction as well as long-term hypertension induced heart failure. In this study, we examined whether PARP-inhibitor (L-2286 treatment could prevent the development of hypertensive cardiopathy in SHRs. 6-week-old SHR animals were treated with L-2286 (SHR-L group or placebo (SHR-C group for 24 weeks. Wistar-Kyoto rats were used as aged-matched, normotensive controls (WKY group. Echocardiography was performed, brain-derived natriuretic peptide (BNP activity and blood pressure were determined at the end of the study. We detected the extent of fibrotic areas. The amount of heat-shock proteins (Hsps and the phosphorylation state of Akt-1(Ser473, glycogen synthase kinase (GSK-3β(Ser9, forkhead transcription factor (FKHR(Ser256, mitogen activated protein kinases (MAPKs, and protein kinase C (PKC isoenzymes were monitored. The elevated blood pressure in SHRs was not influenced by PARP-inhibitor treatment. Systolic left ventricular function and BNP activity did not differ among the three groups. L-2286 treatment decreased the marked left ventricular (LV hypertrophy which was developed in SHRs. Interstitial collagen deposition was also decreased by L-2286 treatment. The phosphorylation of extracellular signal-regulated kinase (ERK1/2(Thr183-Tyr185, Akt-1(Ser473, GSK-3β(Ser9, FKHR(Ser256, and PKC ε(Ser729 and the level of Hsp90 were increased, while the activity of PKC α/βII(Thr638/641, ζ/λ(410/403 were mitigated by L-2286 administration. We could detect signs of LV hypertrophy without congestive heart failure in SHR groups. This alteration was prevented by PARP inhibition. Our results suggest that PARP-inhibitor treatment has protective effect already in the early stage of hypertensive myocardial remodeling.

  7. Evaluation of cerebral electrical activity and cardiac output after patent ductus arteriosus ligation in preterm infants.

    LENUS (Irish Health Repository)

    Leslie, A T F S

    2013-11-01

    To characterize and investigate the relationship between systemic blood flow and pre- and postoperative cerebral electrical activity in preterm neonates undergoing patent ductus arteriosus (PDA) ligation.

  8. Mechanical cardiac remodeling and new-onset atrial fibrillation in long-term follow-up of subjects with chronic Chagas' disease

    Directory of Open Access Journals (Sweden)

    P.R. Benchimol-Barbosa

    2009-03-01

    Full Text Available Atrial fibrillation (AF affects subjects with Chagas' disease and is an indicator of poor prognosis. We investigated clinical, echocardiographic and electrocardiographic variables of Chagas' disease in a long-term longitudinal study as predictors of a new-onset AF episode lasting >24 h, nonfatal embolic stroke and cardiac death. Fifty adult outpatients (34 to 74 years old, 62% females staged according to the Los Andes classification were enrolled. During a follow-up of (mean ± SD 84.2 ± 39.0 months, 9 subjects developed AF (incidence: 3.3 ± 1.0%/year, 5 had nonfatal stroke (incidence: 1.3 ± 1.0%/year, and nine died (mortality rate: 2.3 ± 0.8%/year. The progression rate of left ventricular mass and left ventricular ejection fraction was significantly greater in subjects who experienced AF (16.4 ± 20.0 g/year and -8.6 ± 7.6%/year, respectively than in those who did not (8.2 ± 8.4 g/year; P = 0.03, and -3.0 ± 2.5%/year; P = 0.04, respectively. In univariate analysis, left atrial diameter ≥3.2 cm (P = 0.002, pulmonary arterial hypertension (P = 0.035, frequent premature supraventricular and ventricular contraction counts/24 h (P = 0.005 and P = 0.007, respectively, ventricular couplets/24 h (P = 0.002, and ventricular tachycardia (P = 0.004 were long-term predictors of AF. P-wave signal-averaged ECG revealed a limited long-term predictive value for AF. In chronic Chagas' disease, large left atrial diameter, pulmonary arterial hypertension, frequent supraventricular and ventricular premature beats, and ventricular tachycardia are long-term predictors of AF. The rate of left ventricular mass enlargement and systolic function deterioration impact AF incidence in this population.

  9. Biomimetic material strategies for cardiac tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Prabhakaran, Molamma P., E-mail: nnimpp@nus.edu.sg [Health Care and Energy Materials Laboratory, Nanoscience and Nanotechnology Initiative, Faculty of Engineering, National University of Singapore, 2 Engineering Drive 3, Singapore 117576 (Singapore); Venugopal, J. [Health Care and Energy Materials Laboratory, Nanoscience and Nanotechnology Initiative, Faculty of Engineering, National University of Singapore, 2 Engineering Drive 3, Singapore 117576 (Singapore); Kai, Dan [NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore (Singapore); Ramakrishna, Seeram [Health Care and Energy Materials Laboratory, Nanoscience and Nanotechnology Initiative, Faculty of Engineering, National University of Singapore, 2 Engineering Drive 3, Singapore 117576 (Singapore)

    2011-04-08

    Cardiovascular disease precedes many serious complications including myocardial infarction (MI) and it remains a major problem for the global community. Adult mammalian heart has limited ability to regenerate and compensate for the loss of cardiomyocytes. Restoration of cardiac function by replacement of diseased myocardium with functional cardiomyocytes is an intriguing strategy because it offers a potential cure for MI. Biomaterials are fabricated in nanometer scale dimensions by combining the chemical, biological, mechanical and electrical aspects of material for potential tissue engineering (TE) applications. Synthetic polymers offer advantageous in their ability to tailor the mechanical properties, and natural polymers offer cell recognition sites necessary for cell, adhesion and proliferation. Cardiac tissue engineering (TE) aim for the development of a bioengineered construct that can provide physical support to the damaged cardiac tissue by replacing certain functions of the damaged extracellular matrix and prevent adverse cardiac remodeling and dysfunction after MI. Electrospun nanofibers are applied as heart muscle patches, while hydrogels serve as a platform for controlled delivery of growth factors, prevent mechanical complications and assist in cell recruitment. This article reviews the applications of different natural and synthetic polymeric materials utilized as cardiac patches, injectables or 3D constructs for cardiac TE. Smart organization of nanoscale assemblies with synergistic approaches of utilizing nanofibers and hydrogels could further advance the field of cardiac tissue engineering. Rapid innovations in biomedical engineering and cell biology will bring about new insights in the development of optimal scaffolds and methods to create tissue constructs with relevant contractile properties and electrical integration to replace or substitute the diseased myocardium.

  10. Nanosecond pulsed platelet-rich plasma (nsPRP) improves mechanical and electrical cardiac function following myocardial reperfusion injury.

    Science.gov (United States)

    Hargrave, Barbara; Varghese, Frency; Barabutis, Nektarios; Catravas, John; Zemlin, Christian

    2016-02-01

    Ischemia and reperfusion (I/R) of the heart is associated with biochemical and ionic changes that result in cardiac contractile and electrical dysfunction. In rabbits, platelet-rich plasma activated using nanosecond pulsed electric fields (nsPRP) has been shown to improve left ventricular pumping. Here, we demonstrate that nsPRP causes a similar improvement in mouse left ventricular function. We also show that nsPRP injection recovers electrical activity even before reperfusion begins. To uncover the mechanism of nsPRP action, we studied whether the enhanced left ventricular function in nsPRP rabbit and mouse hearts was associated with increased expression of heat-shock proteins and altered mitochondrial function under conditions of oxidative stress. Mouse hearts underwent 30 min of global ischemia and 1 h of reperfusion in situ. Rabbit hearts underwent 30 min of ischemia in vivo and were reperfused for 14 days. Hearts treated with nsPRP expressed significantly higher levels of Hsp27 and Hsp70 compared to hearts treated with vehicle. Also, pretreatment of cultured H9c2 cells with nsPRP significantly enhanced the "spare respiratory capacity (SRC)" also referred to as "respiratory reserve capacity" and ATP production in response to the uncoupler FCCP. These results suggest a cardioprotective effect of nsPRP on the ischemic heart during reperfusion.

  11. Why QRS Duration Should Be Replaced by Better Measures of Electrical Activation to Improve Patient Selection for Cardiac Resynchronization Therapy.

    Science.gov (United States)

    Engels, Elien B; Mafi-Rad, Masih; van Stipdonk, Antonius M W; Vernooy, Kevin; Prinzen, Frits W

    2016-08-01

    Cardiac resynchronization therapy (CRT) is a well-known treatment modality for patients with a reduced left ventricular ejection fraction accompanied by a ventricular conduction delay. However, a large proportion of patients does not benefit from this therapy. Better patient selection may importantly reduce the number of non-responders. Here, we review the strengths and weaknesses of the electrocardiogram (ECG) markers currently being used in guidelines for patient selection, e.g., QRS duration and morphology. We shed light on the current knowledge on the underlying electrical substrate and the mechanism of action of CRT. Finally, we discuss potentially better ECG-based biomarkers for CRT candidate selection, of which the vectorcardiogram may have high potential.

  12. Imaging cardiac activity by the D-bar method for electrical impedance tomography

    OpenAIRE

    Isaacson, D; Mueller, J L; Newell, J C; Siltanen, S

    2006-01-01

    A practical D-bar algorithm for reconstructing conductivity changes from EIT data taken on electrodes in a 2D geometry is described. The algorithm is based on the global uniqueness proof of Nachman (1996 Ann. Math. 143 71–96) for the 2D inverse conductivity problem. Results are shown for reconstructions from data collected on electrodes placed around the circumference of a human chest to reconstruct a 2D cross-section of the torso. The images show changes in conductivity during a cardiac cycl...

  13. Vagal cardiac efferent innervation in F344 rats: Effects of chronic intermittent hypoxia.

    Science.gov (United States)

    Cheng, Zixi Jack

    2017-03-01

    Chronic intermittent hypoxia (CIH), which is a physiological consequence of obstructive sleep apnea, reduces baroreflex control of heart rate (HR). Previously, we showed that the heart rate (HR) response to electrical stimulation of the vagal efferent nerve was significantly increased following CIH in F344 rats. Since vagal cardiac efferent from the nucleus ambiguus (NA) project to cardiac ganglia and regulate HR, we hypothesized that vagal cardiac efferent innervation of cardiac ganglia is reorganized. Young adult F344 rats were exposed either to room air (RA) or to intermittent hypoxia for 35-50days. Fluorescent tracer DiI was injected into the NA to label vagal efferent innervation of cardiac ganglia which had been counterstained by Fluoro-Gold (FG) injections (i.p). Confocal microscopy was used to examine vagal cardiac efferent axons and terminals in cardiac ganglia. NA axons entered cardiac ganglia and innervated principal neurons (PNs) with robust basket endings in both RA control and CIH animals. In addition, the percentage of PNs which were innervated by DiI-labeled fibers in ganglia was similar. In CIH rats, abnormally large swollen cardiac axon segments and disorganized terminals as well as leaky endings were observed. In general, vagal efferent terminal varicosities around PNs appeared larger and the number of varicosities was significantly increased. Interestingly, some cardiac axons had sprouting-like terminal structures in the cardiac ganglia as well as in cardiac muscle, which had not been found in RA control. Finally, CIH increased the size of PNs and reduced the ratio of nucleus to PN somata. Thus, CIH significantly remodeled the structure of vagal cardiac axons and terminals in cardiac ganglia as well as cardiac PNs.

  14. CYP2J2 overexpression protects against arrhythmia susceptibility in cardiac hypertrophy.

    Directory of Open Access Journals (Sweden)

    Christina Westphal

    Full Text Available Maladaptive cardiac hypertrophy predisposes one to arrhythmia and sudden death. Cytochrome P450 (CYP-derived epoxyeicosatrienoic acids (EETs promote anti-inflammatory and antiapoptotic mechanisms, and are involved in the regulation of cardiac Ca(2+-, K(+- and Na(+-channels. To test the hypothesis that enhanced cardiac EET biosynthesis counteracts hypertrophy-induced electrical remodeling, male transgenic mice with cardiomyocyte-specific overexpression of the human epoxygenase CYP2J2 (CYP2J2-TG and wildtype littermates (WT were subjected to chronic pressure overload (transverse aortic constriction, TAC or β-adrenergic stimulation (isoproterenol infusion, ISO. TAC caused progressive mortality that was higher in WT (42% over 8 weeks after TAC, compared to CYP2J2-TG mice (6%. In vivo electrophysiological studies, 4 weeks after TAC, revealed high ventricular tachyarrhythmia inducibility in WT (47% of the stimulation protocols, but not in CYP2J2-TG mice (0%. CYP2J2 overexpression also enhanced ventricular refractoriness and protected against TAC-induced QRS prolongation and delocalization of left ventricular connexin-43. ISO for 14 days induced high vulnerability for atrial fibrillation in WT mice (54% that was reduced in CYP-TG mice (17%. CYP2J2 overexpression also protected against ISO-induced reduction of atrial refractoriness and development of atrial fibrosis. In contrast to these profound effects on electrical remodeling, CYP2J2 overexpression only moderately reduced TAC-induced cardiac hypertrophy and did not affect the hypertrophic response to β-adrenergic stimulation. These results demonstrate that enhanced cardiac EET biosynthesis protects against electrical remodeling, ventricular tachyarrhythmia, and atrial fibrillation susceptibility during maladaptive cardiac hypertrophy.

  15. Cardiac sodium channelopathies

    NARCIS (Netherlands)

    Amin, A.S.; Asghari-Roodsari, A.; Tan, H.L.

    2010-01-01

    Cardiac sodium channel are protein complexes that are expressed in the sarcolemma of cardiomyocytes to carry a large inward depolarizing current (I-Na) during phase 0 of the cardiac action potential. The importance of I-Na for normal cardiac electrical activity is reflected by the high incidence of

  16. The Notch pathway: a novel target for myocardial remodelling therapy?

    Science.gov (United States)

    Ferrari, Roberto; Rizzo, Paola

    2014-08-21

    Pathological ventricle remodelling, which follows a cardiac insult, causes heart failure. Despite the existence of multiple pharmaceutical approaches, heart failure is one of the leading causes of death worldwide and there is an urgent need to explore new therapeutic avenues. The Notch pathway is an evolutionary conserved fundamental pathway that regulates cell fate during development as well as throughout postnatal life in self-renewing tissues. In the myocardium, Notch signalling is involved in the modulation of cardiomyocytes survival, cardiac stem cells differentiation, and angiogenesis which are factors known to determine the extent of pathological cardiac remodelling. Modulation of the Notch pathway could become a tool to limit ventricle remodelling and the associated inexorable deterioration of cardiac performance.

  17. Vagal control of cardiac electrical activity and wall motion during ventricular fibrillation in large animals.

    Science.gov (United States)

    Naggar, Isaac; Nakase, Ko; Lazar, Jason; Salciccioli, Louis; Selesnick, Ivan; Stewart, Mark

    2014-07-01

    Vagal inputs control pacemaking and conduction systems in the heart. Anatomical evidence suggests a direct ventricular action, but functional evidence that separates direct and indirect (via the conduction system) vagal actions is less well established. We studied vagus nerve stimulation (VNS) during sinus rhythm and ventricular fibrillation (VF) in pigs and sheep to determine: 1) the range of unilateral and bilateral actions (inotropic and chronotropic) and 2) whether VNS alters left ventricular motion and/or electrical activity during VF, a model of abnormal electrical conduction of the left ventricle that excludes sinus and atrioventricular nodal function. Adult pigs (N=8) and sheep (N=10) were anesthetized with urethane and mechanically ventilated. VNS was performed in animals at 1, 2, 5, 10, 20, 50, and 100Hz for 20s. VF was induced with direct current to the ventricles or occlusion of the left anterior descending coronary artery. In 4 pigs and 3 sheep, left ventricular wall motion was assessed from endocardial excursion in epicardial echocardiography. In sheep and pigs, the best frequency among those tested for VNS during sinus rhythm to produce sustained electrical and mechanical ventricular standstill was 50Hz for unilateral or bilateral stimulation. When applied during VF, bilateral VNS increased the variability of the dominant VF frequency, indicating a direct impact on the excitability of ventricular myocytes, and decreased endocardial excursion by more than 50% during VF. We conclude that the vagus nerve directly modulates left ventricular function independently from its effects on the conduction system.

  18. Regional electroporation of single cardiac myocytes in a focused electric field.

    Science.gov (United States)

    Klauke, Norbert; Smith, Godfrey; Cooper, Jonathan M

    2010-01-15

    There is now a significant interest in being able to locate single cells within geometrically defined regions of a microfluidic chip and to gain intracellular access through the local electroporation of the cell membrane. This paper describes the microfabrication of electroporation devices which can enable the regional electroporation of adult ventricular myocytes, in order to lower the local electrical resistance of the cell membrane. Initially three different devices, designed to suit the characteristic geometry of the cardiomyocyte, were investigated (all three designs serve to focus the electric field to selected regions of the cell). We demonstrate that one of these three devices revealed the sequence of cellular responses to field strengths of increasing magnitudes, namely, cell contraction, hypercontraction, and lysis. This same device required a reduced threshold voltage for each of these events, including in particular membrane breakdown. We were not only able to show the gradual regional increase in the electric conductivity of the cell membrane but were also able to avoid changes in the local intra- and extracellular pH (by preventing the local generation of protons at the electrode surface, as a consequence of the reduced threshold voltage). The paper provides evidence for new strategies for achieving robust and reproducible regional electroporation, a technique which, in future, may be used for the insertion of large molecular weight molecules (including genes) as well as for on-chip voltage clamping of the primary adult cardiomyocyte.

  19. Electrophysiological and structural remodeling in heart failure modulate arrhythmogenesis. 2D simulation study.

    Directory of Open Access Journals (Sweden)

    Juan F Gomez

    Full Text Available Heart failure is operationally defined as the inability of the heart to maintain blood flow to meet the needs of the body and it is the final common pathway of various cardiac pathologies. Electrophysiological remodeling, intercellular uncoupling and a pro-fibrotic response have been identified as major arrhythmogenic factors in heart failure.In this study we investigate vulnerability to reentry under heart failure conditions by incorporating established electrophysiological and anatomical remodeling using computer simulations.The electrical activity of human transmural ventricular tissue (5 cm × 5 cm was simulated using the human ventricular action potential model Grandi et al. under control and heart failure conditions. The MacCannell et al. model was used to model fibroblast electrical activity, and their electrotonic interactions with myocytes. Selected degrees of diffuse fibrosis and variations in intercellular coupling were considered and the vulnerable window (VW for reentry was evaluated following cross-field stimulation.No reentry was observed in normal conditions or in the presence of HF ionic remodeling. However, defined amount of fibrosis and/or cellular uncoupling were sufficient to elicit reentrant activity. Under conditions where reentry was generated, HF electrophysiological remodeling did not alter the width of the VW. However, intermediate fibrosis and cellular uncoupling significantly widened the VW. In addition, biphasic behavior was observed, as very high fibrotic content or very low tissue conductivity hampered the development of reentry. Detailed phase analysis of reentry dynamics revealed an increase of phase singularities with progressive fibrotic components.Structural remodeling is a key factor in the genesis of vulnerability to reentry. A range of intermediate levels of fibrosis and intercellular uncoupling can combine to favor reentrant activity.

  20. 迷走神经干预在心房电重构中的作用研究%The study on the intervention role of vagus nerve in atrial electrical remodeling

    Institute of Scientific and Technical Information of China (English)

    王猛; 曾莉容; 张弢; 林岫芳

    2013-01-01

    目的 探讨迷走神经干预对心房电重构的影响及意义.方法 30条杂种犬给予美托洛尔以消除交感神经对心房电重构的影响;观察使用阿托品前、后及心房电重构后高位右心房(SA)和冠状静脉窦(CS),迷走神经刺激(VS)下或无迷走神经刺激(Non-VS)下的心房有效不应期(ERP)及心房颤动易感窗口(VW).结果 应用阿托品前,VS后发现ERP显著缩短[(54.83 ±46.23) ms],VW显著性增加[(19.86±13.23)ms],此时心房颤动易于发生;使用阿托品后,VS下的ERP明显延长[(112.33±9.63) ms],可并未诱发房颤;心房电经过重构后,基础和VS下的ERP与心房电重构前差异均无统计学意义(t=2.116、0.853,均P>0.05).结论 VS可加重心房电重构,增加心房颤动易感性;迷走神经阻滞能减轻心房电重构,使心房颤动易感性降低.%Objective To investigate the impact and significance of the vagus nerve intervention on the atrial electrical emodeling.Methods 30 mongrel dogs were given metoprolol in order to eliminate the effects of sympathetic nerve on atrial electrical remodeling;observe the atrial effective refractory period (ERP) and atrial fibrillation susceptible window(VW) in the high right atrial(SA) and coronary sinus (CS) by the vagus nerve stimulation(VS) or vagus nerve stimulation(Non-VS) before and after using atropine and after atrial electrical remodeling was observed.Results Before using vagus nerve blocking agents atropine,ERP shortened significantly [(54.83 ± 46.23) ms] and VW increased significantly [(19.86±13.23) ms] after VS,this time with atrial fibrillation-prone ; After using atropine,ERP increased significantly [(112.33 ± 9.63) ms] under VS,did not induce atrial fibrillation; After atrial electrical remodeling,the value of ERP was no significant difference under basis and VS (t =2.116,0.853,all P >0.05).Conclusion VS can increase the atrial electrical remodeling,an increase of atrial fibrillation susceptibility

  1. The Relationship of Left Ventricular Remodeling and Cardiac Function with Ventricular Arrhythmia in Ischemic Cardiomyopathy%缺血性心肌病左室重构和心功能与室性心律失常的关系

    Institute of Scientific and Technical Information of China (English)

    楚涛

    2012-01-01

    目的:探讨缺血性心肌病(ICM)患者左心室重构和心功能与室性心律失常的关系.方法:120例ICM患者分别按左心功能和左心室舒张末期内径(left ventricle end diastolic dimension,LVEDd)分组,分析各组患者发生室性心律失常的情况.结果:ICM患者的复杂型室性早搏、室内传导阻滞、室性早搏并发室内传导阻滞的发生率与LVEDd有明显相关性,差异有显著性(P<0.05);复杂型室性早搏的发生率与左心功能有关,差异有显著性(P<0.05),而室内传导阻滞以及室性早搏并发室内传导阻滞的发生率与左心功能无关,差异无显著性(P>0.05);简单型室性早搏的发生率与LVEDd和左心功能无关,差异无显著性(P>0.05).结论:ICM患者复杂型室性早搏发生与LVEDd及心功能有明显相关性,LVEDd重度增大者更易发生室性早搏及室内传导阻滞.%Objective: To investigate the relationship of left ventricular remodeling and cardiac function with ventricular arrhythmias in patients with ischemic cardiomyopathy (ICM). Methods; Total 120 cases with ICM were divided into groups according to left ventricle end-diastolic dimension (LVEDd) and left ventricular function, and the occurrence of ventricular arrhythmias in each group was investigated. Results; The occurrence of complex ventricular premature beat, intraventricular block and ventricular premature beat complicated with intraventricular block was related to LVEDd ( P 0. 05). Simple type of ventricular premature beat was not related to LVEDd and left heart function (P > 0. 05). Conclusions: The occurrence of complex ventricular premature beat is related to LVEDd and left heart function. When LVEDd is severe enlargement, ventricular premature beat complicated with intraventricular block is more likely to occur.

  2. A coupled 3D-1D numerical monodomain solver for cardiac electrical activation in the myocardium with detailed Purkinje network

    Science.gov (United States)

    Vergara, Christian; Lange, Matthias; Palamara, Simone; Lassila, Toni; Frangi, Alejandro F.; Quarteroni, Alfio

    2016-03-01

    We present a model for the electrophysiology in the heart to handle the electrical propagation through the Purkinje system and in the myocardium, with two-way coupling at the Purkinje-muscle junctions. In both the subproblems the monodomain model is considered, whereas at the junctions a resistor element is included that induces an orthodromic propagation delay from the Purkinje network towards the heart muscle. We prove a sufficient condition for convergence of a fixed-point iterative algorithm to the numerical solution of the coupled problem. Numerical comparison of activation patterns is made with two different combinations of models for the coupled Purkinje network/myocardium system, the eikonal/eikonal and the monodomain/monodomain models. Test cases are investigated for both physiological and pathological activation of a model left ventricle. Finally, we prove the reliability of the monodomain/monodomain coupling on a realistic scenario. Our results underlie the importance of using physiologically realistic Purkinje-trees with propagation solved using the monodomain model for simulating cardiac activation.

  3. Influence of rosuvastatin in left ventricular remodeling and cardiac function after myocardial infarction in rabbits%瑞舒伐他汀对老年兔心肌梗死左室重构和心功能的影响

    Institute of Scientific and Technical Information of China (English)

    陈丹丹; 李加平

    2013-01-01

    Objective To observe and study correlation influence of rosuvastatin in left ventricular remodeling and cardiac function after myocardial infarction in rabbits. Methods Olderly male New Zealand white rabbits were random divided into control group, myocardial infarction group and rosuvastatin group. Myocardial infarction combination rosuvastatin group were established the left anterior descending coronary artery ligation after infarction model, infarction after the establishment of the model to red easy cutting statin calcium from the gastrointestinal tract infusion 4 weeks group for Rosuvastatin group. Before and after molding respectively, left ventricular end-diastolic diameter (LVDD), left ventricular end-systolic diameter (LVDS), left ventricular short axis shorten rate (LVFS) and left ventricular ejection fraction (LVEF) were measured, postoperation muscle cell scar index and muscle cell apoptosis index (AI) was measured. Results The scores and sham operation group comparison, after the success of the infarction myocardial infarction group and red easy cutting statin group of LVFS, LVEF was decreased, but in a way LVDD, LVDS significantly increased (P <0. 01); In myocardial infarction manufacturing model after the success of 14 and 28 d red easy cutting statin group LVDS below myocardial infarction group (P<0. 05 and 0. 01), however LVFS and LVEF were significantly higher than that of myocardial infarction group (P<0. 01) ; In the infarction model after the establishment of the 28 d Rosuvastatin group myocardial scarring index less than myocardial infarction group (P<0. 05); sham operation group AI significantly lower than easy cutting statin group and myocardial infarction group (P<0. 01), but the myocardial infarction group is obviously higher than that of the red easy cutting statin group (P<0. 05). Conclusion Rosuvastatin for elderly rabbit after myocardial infarction myocardial remodeling and cardiac function in a benign influence, its

  4. Mapping cardiac surface mechanics with structured light imaging.

    Science.gov (United States)

    Laughner, Jacob I; Zhang, Song; Li, Hao; Shao, Connie C; Efimov, Igor R

    2012-09-15

    Cardiovascular disease often manifests as a combination of pathological electrical and structural heart remodeling. The relationship between mechanics and electrophysiology is crucial to our understanding of mechanisms of cardiac arrhythmias and the treatment of cardiac disease. While several technologies exist for describing whole heart electrophysiology, studies of cardiac mechanics are often limited to rhythmic patterns or small sections of tissue. Here, we present a comprehensive system based on ultrafast three-dimensional (3-D) structured light imaging to map surface dynamics of whole heart cardiac motion. Additionally, we introduce a novel nonrigid motion-tracking algorithm based on an isometry-maximizing optimization framework that forms correspondences between consecutive 3-D frames without the use of any fiducial markers. By combining our 3-D imaging system with nonrigid surface registration, we are able to measure cardiac surface mechanics at unprecedented spatial and temporal resolution. In conclusion, we demonstrate accurate cardiac deformation at over 200,000 surface points of a rabbit heart recorded at 200 frames/s and validate our results on highly contrasting heart motions during normal sinus rhythm, ventricular pacing, and ventricular fibrillation.

  5. Iron deposition following chronic myocardial infarction as a substrate for cardiac electrical anomalies: initial findings in a canine model.

    Directory of Open Access Journals (Sweden)

    Ivan Cokic

    Full Text Available PURPOSE: Iron deposition has been shown to occur following myocardial infarction (MI. We investigated whether such focal iron deposition within chronic MI lead to electrical anomalies. METHODS: Two groups of dogs (ex-vivo (n = 12 and in-vivo (n = 10 were studied at 16 weeks post MI. Hearts of animals from ex-vivo group were explanted and sectioned into infarcted and non-infarcted segments. Impedance spectroscopy was used to derive electrical permittivity ([Formula: see text] and conductivity ([Formula: see text]. Mass spectrometry was used to classify and characterize tissue sections with (IRON+ and without (IRON- iron. Animals from in-vivo group underwent cardiac magnetic resonance imaging (CMR for estimation of scar volume (late-gadolinium enhancement, LGE and iron deposition (T2* relative to left-ventricular volume. 24-hour electrocardiogram recordings were obtained and used to examine Heart Rate (HR, QT interval (QT, QT corrected for HR (QTc and QTc dispersion (QTcd. In a fraction of these animals (n = 5, ultra-high resolution electroanatomical mapping (EAM was performed, co-registered with LGE and T2* CMR and were used to characterize the spatial locations of isolated late potentials (ILPs. RESULTS: Compared to IRON- sections, IRON+ sections had higher[Formula: see text], but no difference in[Formula: see text]. A linear relationship was found between iron content and [Formula: see text] (p1.5% with similar scar volumes (7.28% ± 1.02% (Iron (1.5%, p = 0.51 but markedly different iron volumes (1.12% ± 0.64% (Iron (1.5%, p = 0.02, QT and QTc were elevated and QTcd was decreased in the group with the higher iron volume during the day, night and 24-hour period (p<0.05. EAMs co-registered with CMR images showed a greater tendency for ILPs to emerge from scar regions with iron versus without iron. CONCLUSION: The electrical behavior of infarcted hearts with iron appears to be different from those without iron. Iron within infarcted zones may

  6. Magnetic Imaging of Applied and Propagating Action Currents in Cardiac Tissue Slices: Determination of Anisotropic Electrical Conductivities in a Two-Dimensional Bidomain.

    Science.gov (United States)

    Staton, Daniel Joseph

    We describe the first, high-resolution magnetic images of applied currents and propagating action currents in slices of canine cardiac tissue. This tissue was maintained in vitro at 37^circC. Our main conclusions are summarized as follows: the action currents produce magnetic fields which are measurable; during the initial stages of the propagating action potential, small, expanding, quatrefoil loops of current develop; the magnetic fields produced by repolarization currents are larger than previously anticipated. Most of the current associated with the propagating action potential is confined within the wavefront and should be magnetically silent; however, differences in the intracellular and extracellular electrical conductivities, in both the longitudinal and transverse fiber directions, are great enough that expanding quatrefoil current densities are associated with the wavefront and produce measurable magnetic fields. Since action currents are affected by the electrical conductivities, it is of interest to determine their values, which depend not only upon the tissue characteristics, but also on the mathematical model used to interpret the measured data. In our analysis of current injection, we use the anisotropic bidomain model which incorporates a passive, linear membrane. We introduce theoretical techniques to calculate the anisotropic conductivities of a two-dimensional bidomain. To apply these techniques to magnetic fields resulting from current injection into cardiac tissue slices, we need to improve the higher spatial frequency content of our present measurements. This may be done by measuring the magnetic field closer to the cardiac slice (presently 2.5 mm), decreasing the sampling interval of the measurement, and increasing the sampling area of the field. Magnetic fields are produced by propagating action currents, which are in turn the result of the propagating action potential. From the magnetic field, we directly image isochronal transmembrane

  7. Influence of cardiac magnetic resonance imaging on the ventricular remodeling after ischemic post-conditioning ST-segment elevation myocardial infarction%心脏核磁共振成像对缺血后处理急性 ST 段抬高型心肌梗死后心室重塑的影响

    Institute of Scientific and Technical Information of China (English)

    陈德华; 郑仕杰; 周敬群; 向常清

    2014-01-01

    目的:探讨心脏核磁共振成像(CMR)对缺血后处理急性 ST 段抬高型心肌梗死(STEMI)后心室重塑的影响。方法选择32例12 h 内行缺血后处理的 STEMI 患者作为实验组及12例健康志愿者作为对照组。2组均于术后6个月行 CMR检查,测量左室心功能指标及梗死心肌面积所占百分比,并以24%为分界值,将实验组又分为无重塑组和重塑组。分析各组间的心功能参数差异,并进行受试者工作特征(ROC)分析。结果与对照组比较,无重塑组与重塑组患者的舒张末期容积(EDV)、收缩末期容积(ESV)和每搏输出量(SV)均明显增加,而射血分数(EF)、PER 和 PFR 均有不同程度的下降,其中重塑组下降的幅度更为显著。ESV 与 EDV 的增大呈线性关系;PFR、PER 和 EF 均随 EDV 的增大而呈线性下降趋势。ROC 分析结果显示,EDV、ESV、EF 和 PFR 的曲线下面积分别为0.741、0.764、0.713和0.743。结论CMR 对预测心室重塑有重要作用,其中 PFR、ESV 和 EDV 可作为独立因子预测心室重塑。%Objective To explore the influence of cardiac magnetic resonance imaging (MRI)on the ventricular remodeling after ischemic post-conditioning ST-segment elevation myocardial infarction (STEMI).Methods 32 STEMI patients treated with ischemic post-conditioning in 12 hours were designed as experimental group,and 12 healthy volunteers were designed as control group.The patients in both groups were given CMR 6 months after surgery,and the left ventricular functional in-dexes and percentage of infarction size were measured.With 24% as the limit value,the experiment group was divided into remodeling and non-remodeling groups.Differences of cardiac functional param-eters and receiver operating characteristic (ROC)were analyzed among groups.Results Compared with control group,end-diastolic volume (EDV),end-systolic volume (ESV)and stroke volume (SV)in remodeling and

  8. Usefulness of short-term variability of QT intervals as a predictor for electrical remodeling and proarrhythmia in patients with nonischemic heart failure

    DEFF Research Database (Denmark)

    Hinterseer, Martin; Beckmann, Britt-Maria; Thomsen, Morten Bækgaard;

    2010-01-01

    The high incidence of sudden cardiac death in heart failure (HF) reflects electrophysiologic changes in response to myocardial failure. We previously showed that short-term variability of QT intervals (STV(QT)) identifies latent repolarization disorders in patients with drug-induced or congenital...

  9. ghrelin调控神经生长因子信号途径介导心肌梗死后神经重构%Ghrelin inhibits cardiac neural remodeling after myocardial infarction in rats

    Institute of Scientific and Technical Information of China (English)

    王广丽; 刘磊; 邓笑伟

    2011-01-01

    Objective Ghrelin is a newly discovered peptide as an endogenous ligand for the growth hormone secretagogue receptor,and has been demonstrated to exert beneficial effect in the cardiovascular system.In the present study,we investigated whether ghrelin administration could inhibit cardiac neural remodeling and sympathetic hyperinnervation after myocardial infarction(MI).Methods Sprague-Dawley rats underwent coronary ligation to induce MI and received rat ghrelin(100μg/kg SC BID)or saline(control).Four weeks after treatment,rats were sacrificed.We examined the expression of nerve growth factor and never markers as well as the mRNA expressions of proinflammatory mediators.We also examined the NF-κB p65 protein and IκBα protein levels by western blot analysis.Results Compared to the control group,ghrelin administration significantly decreased the density of nerve fibers with positive immunostaining for GAP43 and TH,and decreased NGF mRNA and protein levels.Ghrelin also significantly suppressed interleukin-1β,tumor necrosis factor-α,and endothelin-1 mRNA expression,and inhibited NF-κB activation.In the MI rats,the mRNA expression of ET-1 at the non-infarcted zones had a significantly positive correlation with the NGF protein levels.Conclusion Treatment with ghrelin inhibited neural remodeling and sympathetic hyperinnervation,the process may be associated with the inhibition of proinflammatory response and NGF signaling.%目的 ghrelin是最近在胃中分离出来的生长激素释放肽受体的内源性配体,在心血管系统显示出了保护效应.本实验探讨了ghrelin对心肌梗死(MI)后大鼠神经重构的影响及其作用机制.方法 SD大鼠结扎冠状动脉制作MI模型作为对照组,干预组在手术后第1天开始给予ghrelin皮下注射,剂量为100μg/kg,每天两次.对照组开胸后在冠状动脉下穿线,但不结扎,给予盐水作皮下注射.经过4个星期治疗后,处死动物.检测梗死区及梗死边缘区神经生长

  10. Crib death: further support for the concept of fatal cardiac electrical instability as the final common pathway.

    Science.gov (United States)

    Ottaviani, Giulia; Matturri, Luigi; Rossi, Lino; James, Thomas N

    2003-11-01

    This work intends to be a review of the current status of knowledge on the cardiac conduction system in the crib death as well as remaining challenges, including reflections upon authors' personal works as well as many studies by others. The cardiac conduction system findings of resorptive degeneration, His bundle dispersion, Mahaim fibers, cartilaginous meta-hyperplasia, persistent fetal dispersion, left sided His bundle, hemorrhage of the atrio-ventricular junction, septation of the bifurcation, atrio-ventricular node dispersion, sinus node hypoplasia, Zahn node, His bundle hypoplasia, atrio-ventricular node and His bundle dualism are hereby discussed by the authors. The cardiac hypotheses postulating that crib death could be due to lethal cardiac arrhythmias or heart block were considered of great interest in the 1970s. After a general abandon of the conduction studies in crib death, the cardiac concept of crib death is gathering a renewed interest, as well as the occurrence of infantile junctional tachycardia. Both the morphological and functional derangement underlying crib death remain poorly understood, assuring that it remains to be a major medical and social problem. Despite the non-specificity of most of the cardiac conduction findings in crib death, we believe that they, in association with altered neurovegetative stimuli, could underlie potentially malignant arrhythmias, providing a morphologic support for the cardiac concept of crib death.

  11. Comparison of transthoracic electrical bioimpedance cardiac output measurement with thermodilution method in post coronary artery bypass graft patients.

    Science.gov (United States)

    Sharma, Vikas; Singh, Ajmer; Kansara, Bhuvnesh; Karlekar, Anil

    2011-01-01

    Transthoracic electrical bioimpedance (TEB) has been proposed as a non-invasive, continuous, and cost-effective method of cardiac output (CO) measurement. In this prospective, non-randomized, clinical study, we measured CO with NICOMON (Larsen and Toubro Ltd., Mysore, India) and compared it with thermodilution (TD) method in patients after off-pump coronary artery bypass (OPCAB) graft surgery. We also evaluated the effect of ventilation (mechanical and spontaneous) on the measurement of CO by the two methods. Forty-six post-OPCAB patients were studied at five predefined time points during controlled ventilation and at five time points when breathing spontaneously. A total of 230 data pairs of CO were obtained. During controlled ventilation, TD CO values ranged from 2.29 to 6.74 L/min (mean 4.45 ± 0.85 L/min), while TEB CO values ranged from 1.70 to 6.90 L/min (mean 4.43 ± 0.94 L/min). The average correlation (r) was 0.548 (P = 0.0002), accompanied by a bias of 0.015 L/min and precision of 0.859 L/min. In spontaneously breathing patients, TD CO values ranged from 2.66 to 6.92 L/min (mean 4.66 ± 0.76 L/min), while TEB CO values ranged from 3.08 to 6.90 L/min (mean 4.72 ± 0.82 L/min). Their average correlation was relatively poor (r = 0.469, P= 0.002), accompanied by a bias of -0.059 L/min and precision of 0.818 L/min. The overall percent errors between TD CO and TEB CO were 19.3% (during controlled ventilation) and 17.4% (during spontaneous breathing), respectively. To conclude, a fair correlation was found between TD CO and TEB CO measurements among post-OPCAB patients during controlled ventilation. However, the correlation was weak in spontaneously breathing patients.

  12. Comparison of transthoracic electrical bioimpedance cardiac output measurement with thermodilution method in post coronary artery bypass graft patients

    Directory of Open Access Journals (Sweden)

    Sharma Vikas

    2011-01-01

    Full Text Available Transthoracic electrical bioimpedance (TEB has been proposed as a non-invasive, continuous, and cost-effective method of cardiac output (CO measurement. In this prospective, non-randomized, clinical study, we measured CO with NICOMON (Larsen and Toubro Ltd., Mysore, India and compared it with thermodilution (TD method in patients after off-pump coronary artery bypass (OPCAB graft surgery. We also evaluated the effect of ventilation (mechanical and spontaneous on the measurement of CO by the two methods. Forty-six post-OPCAB patients were studied at five predefined time points during controlled ventilation and at five time points when breathing spontaneously. A total of 230 data pairs of CO were obtained. During controlled ventilation, TD CO values ranged from 2.29 to 6.74 L/min (mean 4.45 ± 0.85 L/min, while TEB CO values ranged from 1.70 to 6.90 L/min (mean 4.43 ± 0.94 L/min. The average correlation (r was 0.548 (P = 0.0002, accompanied by a bias of 0.015 L/min and precision of 0.859 L/min. In spontaneously breathing patients, TD CO values ranged from 2.66 to 6.92 L/min (mean 4.66 ± 0.76 L/min, while TEB CO values ranged from 3.08 to 6.90 L/min (mean 4.72 ± 0.82 L/min. Their average correlation was relatively poor (r = 0.469, P= 0.002, accompanied by a bias of −0.059 L/min and precision of 0.818 L/min. The overall percent errors between TD CO and TEB CO were 19.3% (during controlled ventilation and 17.4% (during spontaneous breathing, respectively. To conclude, a fair correlation was found between TD CO and TEB CO measurements among post-OPCAB patients during controlled ventilation. However, the correlation was weak in spontaneously breathing patients.

  13. Cardiac output measured by electrical velocimetry in the CT suite correlates with coronary artery enhancement: a feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Flinck, Marianne; Graden, Aasa; Milde, Helen; Flinck, Agneta; Hellstroem, Mikael (Dept. of Radiology, Sahlgrenska Univ. Hospital and Sahlgrenska Academy at Goetenborg Univ., Goeteborg (Sweden)); Bjoerk, Jonas (Competence Centre for Clinical Research, Lund Univ. Hospital, Lund (Sweden)); Nyman, Ulf (Dept. of Radiology, Lasarettet Trelleborg, Univ. of Lund, Trelleborg (Sweden)), e-mail: ulf.nyman@skane.se

    2010-10-15

    Background: Cardiac output (CO) is inversely related to vascular contrast medium (CM) enhancement during computed tomography (CT). Impedance cardiography with a new technique, electrical velocimetry (EV), may create opportunities to measure CO pre-examination for adaptation of CM injection parameters. Purpose: To relate COEV measured by radiology staff to aortic attenuation as a measure of coronary artery attenuation during CT coronary angiography (CTCA), and to formulate a tentative statistical model to adapt CM injection parameters to CO. Material and Methods: COEV was measured immediately before 100 kVp CTCA (64-multirow detector) in 27 patients with presumed coronary artery disease. For CTCA, 260 mg I/kg (maximum dosage weight: 80/90 kg for women/men) was injected intravenously during 12 s. Simple linear regression analysis was performed to explore the correlation between aortic attenuation (Hounsfield units, HU) and body weight, the influence of COEV on aortic attenuation adjusted to injected CM dose rate (HU per mg I/kg/s), and to establish a tentative formula on how to adapt CM injection parameters to COEV and desired aortic attenuation. Results: The correlation between aortic attenuation and body weight was weak and non-significant (r=-0.14 after outlier exclusion). A significant negative correlation (r=-0.63) was found between aortic attenuation adjusted to injected CM dose rate (HU per mg I/kg/s) and COEV. The resulting formula, CM dose rate=COEVx(aortic attenuation-240)/55, made it possible to calculate CM volumes and injection rates at various COs and, for example, the present mean aortic attenuation (438 HU), injection time (12 s), CM concentration (320 mg I/ml), and a certain body weight. Conclusion: EV makes it possible to measure CO in the CT suite before vascular examinations. Hence, CM doses may be decreased in low CO states to reduce the risk of CM-induced nephropathy without jeopardizing diagnostic quality and may be increased in high CO states

  14. Cardiomyopathy induced by artificial cardiac pacing: myth or reality sustained by evidence?

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    Andrés Di Leoni Ferrari

    2014-09-01

    Full Text Available Implantable cardiac pacing systems are a safe and effective treatment for symptomatic irreversible bradycardia. Under the proper indications, cardiac pacing might bring significant clinical benefit. Evidences from literature state that the action of the artificial pacing system, mainly when the ventricular lead is located at the apex of the right ventricle, produces negative effects to cardiac structure (remodeling, dilatation and function (dissinchrony. Patients with previously compromised left ventricular function would benefit the least with conventional right ventricle apical pacing, and are exposed to the risk of developing higher incidence of morbidity and mortality for heart failure. However, after almost 6 decades of cardiac pacing, just a reduced portion of patients in general would develop these alterations. In this context, there are not completely clear some issues related to cardiac pacing and the development of this cardiomyopathy. Causality relationships among QRS widening with a left bundle branch block morphology, contractility alterations within the left ventricle, and certain substrates or clinical (previous systolic dysfunction, structural heart disease, time from implant or electrical conditions (QRS duration, percentage of ventricular stimulation are still subjecte of debate. This review analyses contemporary data regarding this new entity, and discusses alternatives of how to use cardiac pacing in this context, emphasizing cardiac resynchronization therapy.

  15. Measuring and mapping cardiac fiber and laminar architecture using diffusion tensor MR imaging.

    Science.gov (United States)

    Helm, Patrick; Beg, Mirza Faisal; Miller, Michael I; Winslow, Raimond L

    2005-06-01

    The ventricular myocardium is known to exhibit a complex spatial organization, with fiber orientation varying as a function of transmural location. It is now well established that diffusion tensor magnetic resonance imaging (DTMRI) may be used to measure this fiber orientation at high spatial resolution. Cardiac fibers are also known to be organized in sheets with surface orientation varying throughout the ventricles. This article reviews results on use of DTMRI for measuring ventricular fiber orientation, as well as presents new results providing strong evidence that the tertiary eigenvector of the diffusion tensor is aligned locally with the cardiac sheet surface normal. Considered together, these data indicate that DTMRI may be used to reconstruct both ventricular fiber and sheet organization. This article also presents the large deformation diffeomorphic metric mapping (LDDMM) algorithm and shows that this algorithm may be used to bring ensembles of imaged and reconstructed hearts into correspondence (e.g., registration) so that variability of ventricular geometry, fiber, and sheet orientation may be quantified. Ventricular geometry and fiber structure is known to be remodeled in a range of disease processes; however, descriptions of this remodeling have remained subjective and qualitative. We anticipate that use of DTMRI for reconstruction of ventricular anatomy coupled with application of the LDDMM method for image volume registration will enable the detection and quantification of changes in cardiac anatomy that are characteristic of specific disease processes in the heart. Finally, we show that epicardial electrical mapping and DTMRI imaging may be performed in the same hearts. The anatomic data may then be used to simulate electrical conduction in a computational model of the very same heart that was mapped electrically. This facilitates direct comparison and testing of model versus experimental results and opens the door to quantitative measurement

  16. Echocardiographic evaluation of pressure overload-induced cardiac remodeling in mice using different ultrasound machines%小动物超声仪与临床用超声仪评价小鼠心脏重构的对比分析

    Institute of Scientific and Technical Information of China (English)

    赵静; 曾智; 颜亮; 纪丽景; 罗滔; 宾建平; 廖禹林

    2011-01-01

    目的 比较不同类型超声仪对小鼠压力负荷下心脏重构的评价结果.方法 C57 BL/6小鼠18只,随机分为假手术(sham)组和主动脉弓缩窄(TAC)组,每组9只.手术8周后,首先应用连接15L8高频探头的临床用西门子超声仪测定TAC组小鼠心功能,并比较清醒和麻醉状态下的差异.然后比较西门子超声仪和小动物用高分辨超声仪(Vevo770)对心功能评价的影响.结果 与清醒状态相比,异氟烷吸入麻醉小鼠的心率和左室短轴缩短率显著降低(P<0.001),而左室内径显著增加(P<0.05).但与相应的sham组比较,两种仪器都可以较敏感地反映TAC组的心脏重构.与西门子超声仪相比,小动物超声仪的分辨率明显增高,并可通过二尖瓣血流频谱图评价左室舒张功能,但暂不能在小鼠清醒状态下评价心功能.结论 麻醉本身会降低心功能,但在反映干预手段对心脏重构的影响程度上与清醒状态下有可比性.高分辨小动物超声仪在评价左室舒张功能方面优于西门子超声仪.%To compare the results of echocardiographic evaluation of pressure overload-induced cardiac remodeling in mice using different ultrasound machines. Methods Eighteen C57 BL/6 mice were randomly divided into the sham-operated and the transverse aortic constriction (TAC) groups (n=9). Eight weeks after the operation, the cardiac function of TAC group was evaluated using Siemens ultrasonic instrument with 15L8 probe and the differences between the awake and anesthetized states were compared. The heart rate, left ventricular (LV) dimensions, systolic and diastolic functions were measured in both sham-operated and TAC groups using the Siemens ultrasonic instrument and a high-resolution ultrasonic imaging system for small animals (Vevo 770). Results Compared with the mice in wakefulness, the anesthetized mice showed significantly decreased heart rate and LV fractional shortening (P<0.001) and markedly increased LV end

  17. Effects of erythropoietin on advanced pulmonary vascular remodelling

    NARCIS (Netherlands)

    van Albada, M. E.; Sarvaas, G. J. du Marchie; Koster, J.; Houwertjes, M. C.; Berger, R. M. F.; Schoemaker, R. G.

    2008-01-01

    Erythropoietin (EPO) mobilises endothelial progenitor cells and promotes neovascularisation in heart failure. The present authors studied the effects of EPO on pulmonary vascular and cardiac remodelling in a model for flow-associated pulmonary arterial hypertension (PAH). PAH was induced in adult ma

  18. Do mathematical model studies settle the controversy on the origin of cardiac synchronous trans-thoracic electrical impedance variations? A systematic review.

    Science.gov (United States)

    de Sitter, A; Verdaasdonk, R M; Faes, T J C

    2016-09-01

    Impedance cardiography (ICG) is a method to evaluate cardiac-stroke volume and cardiac-output by measuring the cardiac-synchronous changes in the dynamic trans-thoracic electrical impedance (ΔZ). Clinical evaluations on the accuracy of ICG showed varying results. Consequently, the classic assumption in ICG-the aorta as a main source of ΔZ-is questioned and subsequently investigated in simulation studies using mathematical models of the electrical resistivity of the human body. The aim is to review the consensus in mathematical modelling studies that investigate the origin of the ΔZ as measured in ICG. In a systematic literature search, studies were identified and surveyed with reference to characteristics, such as included organs and their resistivity and geometries, electrode positions and calculation of ΔZ, to review the consensus between mathematical modelling studies that investigate the origin of the ΔZ as measured in ICG. Thirteen papers showed considerable variation in the model's characteristics with varying or contradicting outcomes for the ΔZ 's origin. For instance, 11 studies excluded perfused muscle tissue, implying implicitly their insignificance, while 3 other studies included muscle tissue and indicated it as the most important origin of ΔZ. In conclusion, the reviewed papers show a lack of consensus with respect to both the modelled characteristics as well as the model outcomes and, as a result, these studies failed to settle the controversy on ΔZ 's origin. Recommendations have been added to improve future mathematical model studies.

  19. Remodeling A School Shop?

    Science.gov (United States)

    Baker, G. E.

    1970-01-01

    Presents guidelines for remodeling a school shop combining major considerations of funds, program changes, class management, and flexibility, with the needs of wiring, painting, and placement of equipment. (Author)

  20. Myocardial remodeling and bioelectric changes in tachycardia-induced heart failure in dogs

    Energy Technology Data Exchange (ETDEWEB)

    Song, B.; Wang, B.N.; Chen, D.N.; Luo, Z.G. [Department of Cardiovascular Medicine, The First Affiliated Hospital, Anhui Medical University, HeFei, Anhui Province (China)

    2013-09-06

    In this study, electrical and structural remodeling of ventricles was examined in tachycardia-induced heart failure (HF). We studied two groups of weight-matched adult male mongrel dogs: a sham-operated control group (n=5) and a pacing group (n=5) that underwent ventricular pacing at 230 bpm for 3 weeks. Clinical symptoms of congestive HF were observed in both groups. Their hemodynamic parameters were determined and the severity of the HF was evaluated by M-mode echocardiography. Changes in heart morphology were observed by scanning electron and light microscopy. Ventricular action potential duration (APD), as well as the 50 and 90% APD were measured in both groups. All dogs exhibited clinical symptoms of congestive HF after rapid right ventricular pacing for 3 weeks. These data indicate that rapid, right ventricular pacing produces a useful experimental model of low-output HF in dogs, characterized by biventricular pump dysfunction, biventricular cardiac dilation, and non-ischemic impairment of left ventricular contractility. Electrical and structural myocardial remodeling play an essential role in congestive HF progression, and should thus be prevented.

  1. Mouse models of SCN5A-related cardiac arrhythmias

    Directory of Open Access Journals (Sweden)

    Flavien eCharpentier

    2012-06-01

    Full Text Available Mutations of SCN5A gene, which encodes the α-subunit of the voltage-gated Na+ channel NaV1.5, underlie hereditary cardiac arrhythmic syndromes such as the type 3 long QT syndrome, cardiac conduction diseases, the Brugada syndrome, the sick sinus syndrome, atrial standstill and numerous overlap syndromes. Patch-clamp studies in heterologous expression systems have provided important information to understand the genotype-phenotype relationships of these diseases. However, they could not clarify how SCN5A mutations can be responsible for such a large spectrum of diseases, for the late age of onset or the progressiveness of some of these diseases and for the overlapping syndromes. Genetically modified mice rapidly appeared as promising tools for understanding the pathophysiological mechanisms of cardiac SCN5A-related arrhythmic syndromes and several mouse models have been established. This paper reviews some of the results obtained on these models that, for most of them, recapitulate the clinical phenotypes of the patients. It also points out that these models also have their own limitations. Overall, mouse models appear as powerful tools to elucidate the pathophysiological mechanisms of SCN5A-related diseases and offer the opportunity to investigate the secondary cellular consequences of SCN5A mutations such as the expression remodelling of other genes that might participate to the overall phenotype. Finally, they constitute useful tools for addressing the role of genetic and environmental modifiers on cardiac electrical activity.

  2. Cardiac electrical defects in progeroid mice and Hutchinson–Gilford progeria syndrome patients with nuclear lamina alterations

    Science.gov (United States)

    Rivera-Torres, José; Calvo, Conrado J.; Llach, Anna; Guzmán-Martínez, Gabriela; Caballero, Ricardo; González-Gómez, Cristina; Jiménez-Borreguero, Luis J.; Guadix, Juan A.; Osorio, Fernando G.; López-Otín, Carlos; Herraiz-Martínez, Adela; Cabello, Nuria; Vallmitjana, Alex; Benítez, Raul; Gordon, Leslie B.; Pérez-Pomares, José M.; Tamargo, Juan; Delpón, Eva; Hove-Madsen, Leif; Filgueiras-Rama, David; Andrés, Vicente

    2016-01-01

    Hutchinson–Gilford progeria syndrome (HGPS) is a rare genetic disease caused by defective prelamin A processing, leading to nuclear lamina alterations, severe cardiovascular pathology, and premature death. Prelamin A alterations also occur in physiological aging. It remains unknown how defective prelamin A processing affects the cardiac rhythm. We show age-dependent cardiac repolarization abnormalities in HGPS patients that are also present in the Zmpste24−/− mouse model of HGPS. Challenge of Zmpste24−/− mice with the β-adrenergic agonist isoproterenol did not trigger ventricular arrhythmia but caused bradycardia-related premature ventricular complexes and slow-rate polymorphic ventricular rhythms during recovery. Patch-clamping in Zmpste24−/− cardiomyocytes revealed prolonged calcium-transient duration and reduced sarcoplasmic reticulum calcium loading and release, consistent with the absence of isoproterenol-induced ventricular arrhythmia. Zmpste24−/− progeroid mice also developed severe fibrosis-unrelated bradycardia and PQ interval and QRS complex prolongation. These conduction defects were accompanied by overt mislocalization of the gap junction protein connexin43 (Cx43). Remarkably, Cx43 mislocalization was also evident in autopsied left ventricle tissue from HGPS patients, suggesting intercellular connectivity alterations at late stages of the disease. The similarities between HGPS patients and progeroid mice reported here strongly suggest that defective cardiac repolarization and cardiomyocyte connectivity are important abnormalities in the HGPS pathogenesis that increase the risk of arrhythmia and premature death. PMID:27799555

  3. Functional Alterations of Ion Channels From Cardiac Fibroblasts in Heart Diseases

    Directory of Open Access Journals (Sweden)

    Gracious R. Ross

    2016-11-01

    Full Text Available In an aged population, cardiovascular disease is the leading cause of fatality and morbidity. Age-related fibrotic remodeling of the heart contributes to progressive myocardial dysfunction. Cardiac fibroblasts (CF, responsible for the maintenance of extracellular matrix and fibrosis process, play an important role in cardiac health and disease. CFs influence myocardial function by their chemical, electrical and mechanical interactions with cardiomyocytes through extracellular matrix deposition or secretion of cytokines and growth factors. These, in turn, are modulated by ion channels, macromolecular pores in the plasma membrane that allow selective ionic fluxes of major ions like K+, Ca2+, Na+ or Cl-, which affect membrane potential and cellular signal transduction. The importance of ion channels in modulating various functions of CFs, including proliferation, differentiation, secretion and apoptosis, is being recognized from recent studies of CFs from animal models and tissue from patients with various cardiac pathologies. Understanding the role of ion channels in CFs under physiological conditions and their alterations in age-related cardiac diseases may help facilitate development of novel therapeutic strategies to limit cardiac fibrosis and its adverse effect on myocardial function. This narrative review summarizes the knowledge gained thus far on ion channels in CFs and their relationship with cardiac diseases in human and experimental animal models.

  4. Left Atrial Reverse Remodeling: Mechanisms, Evaluation, and Clinical Significance.

    Science.gov (United States)

    Thomas, Liza; Abhayaratna, Walter P

    2017-01-01

    The left atrium is considered a biomarker for adverse cardiovascular outcomes, particularly in patients with left ventricular diastolic dysfunction and atrial fibrillation in whom left atrial (LA) enlargement is of prognostic importance. LA enlargement with a consequent decrease in LA function represents maladaptive structural and functional "remodeling" that in turn promotes electrical remodeling and a milieu conducive for incident atrial fibrillation. Medical and nonmedical interventions may arrest this pathophysiologic process to the extent that subsequent reverse remodeling results in a reduction in LA size and improvement in LA function. This review examines cellular and basic mechanisms involved in LA remodeling, evaluates the noninvasive techniques that can assess these changes, and examines potential mechanisms that may initiate reverse remodeling.

  5. Effect of spironolactone on atrial structural remodeling and electrical remodeling in the canine atrial fibrillation model%螺内酯在犬心房颤动模型中对心房结构重构及电重构的影响

    Institute of Scientific and Technical Information of China (English)

    吕云波; 曾秋棠; 钟金鹏

    2013-01-01

    Obiective:To observe the effect of spironolactone on atrial structure remodeling and electrical remodeling in the canine atrial fibrillation model.Method:Twenty-four healthy adult dogs were selected and randomly divided into control group (n=8,normal feeding),atrial fibrillation group (n=8,pacemaker implantation and normal feeding) and spironolactone group (n=8,pacemaker implantation and spironolactone intervention).Pacemaker implantation and rapid atrial pacing were adopted to establish the canine atrial fibrillation model.After a week the model was successfully established and left atrial tissue was taken to determination the level of matrix metalloproteinase (MMP)-9,tissue inhibitor-1 of MMP (TIMP-1) and miRNA-101.Then we compared the above indexes between different groups.Result:Compared to control group,the level of MMP-9,MMP-9/TIMP-1 ratio were significantly higher in atrial fibrillation group and spironolactone group (both P<0.01),the level of TIMP1 was significantly lower in atrial fibrillation group (P<0.01) and was significantly higher in spironolactone group (P<0.01); Compared to atrial fibrillation group,the level of MMP-9 in spironolactone group was lower (P<0.05),the expression of TIMP-1 was higher (P < 0.05),the ratio of MMP-9/TIMP-1 declined (P< 0.05).Quantitative analysis showed that the miRNA-101 in atrial fibrillation group obviously down-regulated compared with in control group and spironolactone group (both P<0.05),and it didn't show statistically significant difference between spironolactone group and control group.Conclusion:Atrial fibrillation caused by rapid atrial pacing could lead atrial structural remodeling and electrical remodeling.Spironolactone intervention could up-regulate miRNA-101,decrease MMP-9 levels and elevate TIMP-1 levels,which play a role of prevention and treatment for atrial fibrillation.%目的:观察螺内酯在犬心房颤动(房颤)模型中对心房结构重构和电重构的影响.方法:24只健康

  6. Berberine treatment prevents cardiac dysfunction and remodeling through activation of 5'-adenosine monophosphate-activated protein kinase in type 2 diabetic rats and in palmitate-induced hypertrophic H9c2 cells.

    Science.gov (United States)

    Chang, Wenguang; Zhang, Ming; Meng, Zhaojie; Yu, Yang; Yao, Fan; Hatch, Grant M; Chen, Li

    2015-12-15

    Diabetic cardiomyopathy is the major cause of death in type 2 diabetic patients. Berberine is an isoquinoline alkaloid extract from traditional chinese herbs and its hypoglycemic and hypolipidemic effects make it a promising drug for treatment of type 2 diabetes. We examined if berberine improved cardiac function and attenuated cardiac hypertrophy and fibrosis in high fat diet and streptozotocin induced-type 2 diabetic rats in vivo and reduced expression of hypertrophy markers in palmitate-induced hypertrophic H9c2 cells in vitro. Treatment of diabetic animals with berberine partially improved cardiac function and restored fasting blood insulin, fasting blood glucose, total cholesterol, and triglyceride levels to that of control. In addition, berberine treatment of diabetic animals increased cardiac 5'-adenosine monophosphate-activated protein kinase (AMPK) and protein kinase B (AKT) activation and reduced glycogen synthase kinase 3 beta (GSK3β) activation compared to control. Palmitate incubation of H9c2 cells resulted in cellular hypertrophy and decreased expression of alpha-myosin heavy chain (α-MHC) and increased expression of beta-myosin heavy chain (β-MHC) compared to controls. Berberine treatment of palmitate-incubated H9c2 cells reduced hypertrophy, increased α-MHC expression and decreased β-MHC expression. In addition, berberine treatment of palmitate-incubated H9c2 cells increased AMPK and AKT activation and reduced GSK3β activation. The presence of the AMPK inhibitor Compound C attenuated the effects of berberine. The results strongly indicate that berberine treatment may be protective against the development of diabetic cardiomyopathy.

  7. Association between the polymorphism of A9570G in angiotensin I converting enzyme 2 gene and cardiac dysfunction and ventricular remodeling after myocardial infarction%ACE2基因多态性与心肌梗死后心功能不全及心室重构的相关性研究

    Institute of Scientific and Technical Information of China (English)

    陈文忠; 周永健; 周劲东; 李志樑; 徐春生

    2010-01-01

    Objective To determine the effects of polymorphism of A9570G in angiotensin I converting enzyme 2 gene ( ACE2) gene on cardiac dysfunction and ventricular remodeling after myocardial infarction. Methods 252 patients with old myccardial infarction were included in this study. They were classified according to their polymorphisms of ACE 2 gene analyzed by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). Echocardiograms were used to determine left ventricular end diastolic diameters (LVEDd) , Left ventricular mass index (LVMI) , mitral flow pattern early diastolic and late diastolic peak flow ratio (E/A) and left ventricular ejection fraction ( LVEF). Results In male, LVEDd, LVMI, and LVEF had significant difference among ACE2 genotypes ( t = 2. 609,3.527and 2.063, P =0.010,0.001 and 0.041), and no significant differences in E/A( t =0.689,P =0.492). In female,LVEDd, LVMI, E/A and LVEF had no significant difference among ACE2 genotypes( F =0. 848, 0.077,0. 985 and 1.611, P = 0. 432,0. 926,0. 377 and 0. 205 ). Conclusion The polymorphism of A9570G in ACE2 gene may be associated with cardiac dysfunction and ventricular remodeling after myocardial infarction in male. ACE 2 gene polymorphism may be a genetic factor on cardiac dysfunction and ventricular remodeling after myocardial infarction.%目的 研究血管紧张素转换酶2基因A9570G多态性与心肌梗死后心功能不全及心室重构的关系.方法 收集252例陈旧性心肌梗死患者,采取外周血2ml提取DNA,多聚酶链扩增反应及限制性内切酶法检测ACE2基因A9570G基因型,按基因型进行分组,采用超声心动图比较不同基因型间患者LVEF,E/A,LVEDd及LVMI的差异.结果 在男性,G基因型组LVEF、LVEDd、LVMI与A基因型组比较,差异有统计学意义(t=2.609、3.527、2.063,P0.05);在女性,3种基因型间患者LVEF、E/A、LVEDd及LVMI差异均无统计学意义(P>0.05).结论 ACE2基因A9570G多态性与男性心肌梗死后

  8. Data analysis in cardiac arrhythmias.

    Science.gov (United States)

    Rodrigo, Miguel; Pedrón-Torecilla, Jorge; Hernández, Ismael; Liberos, Alejandro; Climent, Andreu M; Guillem, María S

    2015-01-01

    Cardiac arrhythmias are an increasingly present in developed countries and represent a major health and economic burden. The occurrence of cardiac arrhythmias is closely linked to the electrical function of the heart. Consequently, the analysis of the electrical signal generated by the heart tissue, either recorded invasively or noninvasively, provides valuable information for the study of cardiac arrhythmias. In this chapter, novel cardiac signal analysis techniques that allow the study and diagnosis of cardiac arrhythmias are described, with emphasis on cardiac mapping which allows for spatiotemporal analysis of cardiac signals.Cardiac mapping can serve as a diagnostic tool by recording cardiac signals either in close contact to the heart tissue or noninvasively from the body surface, and allows the identification of cardiac sites responsible of the development or maintenance of arrhythmias. Cardiac mapping can also be used for research in cardiac arrhythmias in order to understand their mechanisms. For this purpose, both synthetic signals generated by computer simulations and animal experimental models allow for more controlled physiological conditions and complete access to the organ.

  9. Structural remodeling and mechanical function in heart failure.

    Science.gov (United States)

    Leonard, Bridget Louise; Smaill, Bruce Henry; LeGrice, Ian John

    2012-02-01

    The cardiac extracellular matrix (ECM) is the three-dimensional scaffold that defines the geometry and muscular architecture of the cardiac chambers and transmits forces produced during the cardiac cycle throughout the heart wall. The cardiac ECM is an active system that responds to the stresses to which it is exposed and in the normal heart is adapted to facilitate efficient mechanical function. There are marked differences in the short- and medium-term changes in ventricular geometry and cardiac ECM that occur as a result of volume overload, hypertension, and ischemic cardiomyopathy. Despite this, there is a widespread view that a common remodeling "phenotype" governs the final progression to end-stage heart failure in different forms of heart disease. In this review article, we make the case that this interpretation is not consistent with the clinical and experimental data on the topic. We argue that there is a need for new theoretical and experimental models that will enable stresses acting on the ECM and resultant deformations to be estimated more accurately and provide better spatial resolution of local signaling mechanisms that are activated as a result. These developments are necessary to link the effects of structural remodeling with altered cardiac mechanical function.

  10. 丹红注射液对心肌梗死大鼠心功能和左室重构的改善作用%The improvement effect of Danhong injection on the cardiac function and left ventricular remodeling in myocardial infarction rats

    Institute of Scientific and Technical Information of China (English)

    李骏峰; 王虹; 贾玲; 邢永红; 王育新

    2013-01-01

    目的:探讨丹红注射液(DHI)对心肌梗死大鼠的心功能和左室重构的改善作用.方法:采用冠状动脉结扎法(CAL)制备心肌梗死(MI)模型,观察DHI对大鼠心肌梗死后12周的心脏及肺的解剖学指标、心室的疤痕面积、左心室血流动力学指标、心肌病理指标及凋亡基因水平的影响.结果:心肌梗死后连续12周的DHI治疗可降低心脏和湿肺与体质量的比值、左室舒张末期压力、心肌细胞直径和胶原容积分数(P<0.05),升高左心室内压最大上升速率(P<0.05),但对凋亡基因的异常表达和心室前壁出现梗死疤痕无明显作用(P>0.05).结论:丹红注射液可有效逆转CAL诱导的心肌梗死大鼠的心功能恶化并改善除凋亡外的心室重构.%OBJECTIVE To explore the improving effect of Danhong injection(DHI)on the cardiac function and left ventricular remodeling in myocardial infarction rats. METHODS Coronary artery ligation (CAD was used to induce an in vivo model of myocardial infarction (MI). The experiment observed the influences of DHI on the anatomy indicators of heart and lung, ventricular scar area, left ventricular hemodynamics, myocardial pathological indicators and the levels of apoptotic genes. RESULTS 12 consecutive weeks' treatment of DHI after myocardial infarction could reduce the ratio of HW/BW and WLW/ BW,left ventricular end-diastolic pressure, the diameter of cardiomyocyte and collagen volume fraction (P<0. 05) ,and increase the maximum rate of change of left ventricular pressure(P<0. 05), while caused no changes on the ventricular scar area and the apoptosis. CONCLUSION Danhong injection can attenuate the deterioration of cardiac function and ventricular remodeling (except the apoptosis) in the myocardial infarction rats.

  11. 体外心脏震波对急性心肌梗死模型猪左心室重塑的影响%Effect of extracorporeal cardiac shock wave therapy on left ventricular remodeling in a porcine model of acute myocardial infarction

    Institute of Scientific and Technical Information of China (English)

    陶四明; 郭涛; 王钰; 李建美; 蔡红雁; 羊超

    2012-01-01

    BACKGROUND: Initial studies have confirmed that extracorporeal cardiac shock wave therapy can ameliorate metabolism of ischemia myocardium from the level of gene and cells. However, will the therapy improve the development of post-infarction ventricular remodeling in a morphology level?OBJECTIVE: To explore the effects of extracorporeal cardiac shockwave therapy on the function and morphology of the left ventricle after acute myocardial infarction.METHODS: A total of 25 pigs were randomly divided into three groups: shock wave group, sham shock wave group and sham operation group. Pigs in the shock wave group were treated with extracorporeal cardiac shock wave therapy on 3, 5 and 7 days after the model construction of myocardial infarction. Pigs in the sham shock wave group received the same therapy to the shock wave group except for the shock waves and energy. Sham operation group received the same treatment to the sham shock wave group without constructing the myocardial infarction model.RESULTS AND CONCLUSION: Compared with the sham shockwave group, shockwave therapy significantly reduced the left ventricular end-systolic volume, increased the end-diastolic volume and improved the global left ventricular function (P< 0.001); it significantly improved the ventricular wall motor function in the myocardium of the myocardial infarction border zone and the motion compatibleness of the left ventricular. These findings demonstrate that the early application of effective extracorporeal cardiac shock wave therapy can delay the development to some extent from reversible stage to irreversible stage in the left ventricular remodeling after myocardial infarction.%背景:初期实验已经证实体外心脏震波治疗可从基因和细胞水平改善缺血心肌代谢,但是否在形态学水平也可缓解梗死后心室重塑的发展?目的:观察体外心脏震波对急性心肌梗死后左心室心功能及形态学指标的影响.方法:将25只猪随机分为3组:震

  12. Pregnancy-induced remodeling of heart valves.

    Science.gov (United States)

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

    2015-11-01

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

  13. Abrogation of CC chemokine receptor 9 ameliorates ventricular remodeling in mice after myocardial infarction.

    Science.gov (United States)

    Huang, Yan; Wang, Dandan; Wang, Xin; Zhang, Yijie; Liu, Tao; Chen, Yuting; Tang, Yanhong; Wang, Teng; Hu, Dan; Huang, Congxin

    2016-01-01

    CC chemokine receptor 9 (CCR9), which is a unique receptor for CC chemokine ligand (CCL25), is mainly expressed on lymphocytes, dendritic cells (DCs) and monocytes/macrophages. CCR9 mediates the chemotaxis of inflammatory cells and participates in the pathological progression of inflammatory diseases. However, the role of CCR9 in the pathological process of myocardial infarction (MI) remains unexplored; inflammation plays a key role in this process. Here, we used CCR9 knockout mice to determine the functional significance of CCR9 in regulating post-MI cardiac remodeling and its underlying mechanism. MI was induced by surgical ligation of the left anterior descending coronary artery in CCR9 knockout mice and their CCR9+/+ littermates. Our results showed that the CCR9 expression levels were up-regulated in the hearts of the MI mice. Abrogation of CCR9 improved the post-MI survival rate and left ventricular (LV) dysfunction and decreased the infarct size. In addition, the CCR9 knockout mice exhibited attenuated inflammation, apoptosis, structural and electrical remodeling compared with the CCR9+/+ MI mice. Mechanistically, CCR9 mainly regulated the pathological response by interfering with the NF-κB and MAPK signaling pathways. In conclusion, the data reveal that CCR9 serves as a novel modulator of pathological progression following MI through NF-κB and MAPK signaling.

  14. Effects of Electrical Spinal Cord Stimulation on Cardiac Ischemic Rat%脊髓电刺激对心肌缺血再灌注损伤大鼠的作用

    Institute of Scientific and Technical Information of China (English)

    苏秋香; 丁晓慧; 姚敏; 解辉; 郭丽; 祁荣; 唐青松; 王璐奇

    2012-01-01

    目的 检测脊髓电刺激对心肌缺血的治疗作用.方法 36只健康成年雄性SD大鼠随机分为对照组、心肌缺血组和脊髓电刺激+心肌缺血组.检测各组P物质在中枢神经系统的表达及心肌缺血组和脊髓电刺激+心肌缺血组心肌缺血面积的大小.结果 与对照组比较,心肌缺血组P物质在中枢神经系统的表达明显增高(P<0.05);脊髓电刺激+心肌缺血组与心肌缺血组比较,脊髓电刺激可减低P物质在心肌缺血时表达的增加(P<0.05).心肌缺血组和脊髓电刺激+心肌缺血组心肌缺血面积占左心室面积的百分比平均值分别为(46.51±2.19)%和(35.33±3.34)%,脊髓电刺激+心肌缺血组与心肌缺血组相比降低30.0%(P< 0.01).结论 脊髓电刺激使心肌缺血时传导痛觉的神经递质P物质在中枢神经系统的表达减少,且降低了心肌缺血损伤面积,对心肌缺血具有治疗作用.%Objective To investigate the effects of electrical spinal cord stimulation on cardiac ischemia area induced by cardiac ischemia reperfusion injury. Methods A total of 36 healthy male adult SD rats were randomly divided into 3 groups (control group, cardiac ischemia group and cardiac ischemia + spinal cord stimulation group). The expression of substance P in central nervous system and the cardiac ischemic area of the latter two groups were observed and compared statistically. Results Compared with the control group, the expression of substance P in central nervous system was increased in cardiac ischemia group (P < 0.05). Comparing cardiac ischemia + spinal cord stimulation group with cardiac ischemia group, (lie spinal cord stimulation could reduce the expression of substance P during cardiac ischemia (P < 0.05). In cardiac ischemia group,the mean ratio of cardiac ischemic area to the left ventricle was about 46.51%±2.19%. In cardiac ischemia + spinal cord stimulation group,the mean ratio of cardiac ischemia area to the left ventricle

  15. 甲状腺功能与老年慢性充血性心力衰竭患者心功能、左心室重构的关系研究%Relationship Between Thyroid Function and Cardiac Function/Left Ventricular Remodeling of Elderly Patients With Chronic Congestive Heart Failure

    Institute of Scientific and Technical Information of China (English)

    张萍; 赵东升

    2016-01-01

    目的:探讨甲状腺功能与老年慢性充血性心力衰竭(CHF)患者心功能、左心室重构的关系。方法选取2013年1月—2015年1月衡水市第二人民医院收治的老年(年龄≥60岁)CHF 患者90例作为 CHF 组,另选取同期于衡水市第二人民医院体检的老年非 CHF 者77例作为对照组。比较两组受检者甲状腺功能、心功能及左心室重构指标,比较不同纽约心脏病协会(NYHA)分级 CHF 患者甲状腺功能指标,分析甲状腺功能指标与左心室重构指标的相关性。结果对照组受检者 NYHA 分级均为Ⅰ级,共77例;CHF 组患者 NYHA 分级Ⅱ级37例,Ⅲ级36例,Ⅳ级17例。CHF 组患者促甲状腺素(TSH)、总三碘甲状腺原氨酸(TT3)、总甲状腺素( TT4)、游离三碘甲状腺原氨酸(FT3)、游离甲状腺素(FT4)水平、左心室射血分数(LVEF)低于对照组,左心室收缩末期内径(LVESD)、左心室舒张末期内径(LVEDD)、左心室质量指数(LVMI)高于对照组(P <0.05)。Ⅲ级 CHF 患者 TSH、TT3、FT3水平低于Ⅱ级 CHF 患者(P <0.05);Ⅳ级 CHF 患者 TSH、TT3、TT4、FT3、FT4水平低于Ⅱ级 CHF 患者,TT3、FT3、FT4水平低于Ⅲ级 CHF 患者(P <0.05)。CHF 组患者 TSH 水平与 LVEDD、LVMI 呈负相关(r 值分别为-0.598、-0.566, P <0.05),TT3水平与 LVESD、LVMI 呈负相关( r 值分别为-0.655、-0.832,P <0.05),TT4水平与 LVESD、LVEDD 呈负相关(r 值分别为-0.738、-0.787,P <0.05),FT3水平与 LVMI 呈负相关( r =-0.540,P <0.05), FT4水平与 LVESD 呈负相关(r =-0.547,P <0.05)。结论甲状腺功能与老年 CHF 患者心功能、左心室重构有关,调节甲状腺功能可改善老年 CHF 患者心功能及左心室重构。%Objective To investigate the relationship between thyroid function and cardiac function/ left ventricular remodeling of elderly patients

  16. 二尖瓣环位移对肥厚性重构患者左室收缩功能的评估作用%Evaluation of left ventricular systolic dysfunction by mitral annular displacement in patients with cardiac hypertrophy and remodeling

    Institute of Scientific and Technical Information of China (English)

    吴卫华; 黄艳; 陆静; 马兰; 魏松霞; 谢晓奕; 刘奇志; 王雷; 杨玲

    2011-01-01

    目的 应用超声二维斑点追踪显像技术测定二尖瓣环位移(MAD),探讨其在评估肥厚性重构所致的早期左室收缩功能减退方面的临床应用价值.方法 选择86例左室射血分数(LVEF)正常(>50%)的各类心肌肥厚(左室壁厚度≥12 mm)患者作为研究对象.采用Philips Sonos iE33超声仪进行检查,先通过M型超声计算出相对室壁厚度(RWT),然后取心尖四腔观分别采集二维和实时三维全容积(RT3D)图像.应用QLAB 6.2在机量化分析软件分别获取MAD相关参数(包括二尖瓣环中点位移和左室长轴缩短率)和经RT3D图像测得左室射血分数(RT3D-LVEF);计算三维心肌重构指标,包括左室舒末容积指数(LVEDVI)和左室质量指数(LVMI).将心肌肥厚患者中RWT<0.45且LVMI在正常范围内的患者归入肥厚正常几何构型组(HNG组),其余归入肥厚重构组(HR组);以46名年龄相匹配的健康志愿者作为正常对照组.结果 HNG组、HR组和正常对照组的RT3D-LVEF均在正常范围内,两两比较差异均无统计学意义(P>0.05).HR组的MAD各值和LVEDVI均显著低于HNG组和正常对照组,差异均有统计学意义(P<0.01或P<0.05);HNG组与正常对照组MAD相关参数值和LVEDVI比较差异均无统计学意义(P>0.05).Bland-Altman分析显示MAD各值的可重复性较高.结论 在心肌肥厚性重构患者中,与LVEF比较,MAD能更早地反映患者的左室收缩功能减退情况.%Objective To investigate the value of mitral annular displacement (MAD) by two-dimensional speckle tracking in evaluating left ventricular systolic dysfunction in patients with cardiac hypertrophy and remodeling.Methods Eightysix patients with cardiac hypertrophy ( left ventricular wall thickness ≥ 12 mm) and normal left ventricular ejection fraction (LVEF) ( > 50% ) were selected.Philips Sonos iE33 ultrasound device was used for examinations.Relative wall thickness (IRWT) was calculated by M mode ultrasound, and two

  17. Metformin Inhibits Angiotensin II-Induced Differentiation of Cardiac Fibroblasts into Myofibroblasts

    OpenAIRE

    Jian Bai; Na Zhang; Ying Hua; Bingjian Wang; Lin Ling; Albert Ferro; Biao Xu

    2013-01-01

    Differentiation of cardiac fibroblasts into myofibroblasts is a critical event in the progression of cardiac fibrosis that leads to pathological cardiac remodeling. Metformin, an antidiabetic agent, exhibits a number of cardioprotective properties. However, much less is known regarding the effect of metformin on cardiac fibroblast differentiation. Thus, in the present study, we examined the effect of metformin on angiotensin (Ang) II-induced differentiation of cardiac fibroblasts into myofibr...

  18. Intra-coronary administration of soluble receptor for advanced glycation end-products attenuates cardiac remodeling with decreased myocardial transforming growth factor-β1 expression and fibrosis in minipigs with ischemia-reperfusion injury

    Institute of Scientific and Technical Information of China (English)

    LU Lin; SHEN Wei-feng; ZHANG Qi; XU Yan; ZHU Zheng-bin; GENG Liang; WANG Ling-jie; JIN Cao; CHEN Qiu-jing; Ann Marie Schmidt

    2010-01-01

    Background The cardioprotective effects of soluble receptor for advanced glycation end-products (sRAGE) have not been evaluated in large animals and the underlying mechanisms are not fully understood. This study aimed to evaluate the effects of intra-coronary administration of sRAGE on left ventricular function and myocardial remodeling in a porcine model of ischemia-reperfusion (I/R) injury. Methods Ten male minipigs with I/R injury were randomly allocated to receive intra-coronary administration of sRAGE (sRAGE group, n=5) or saline (control group, n=5). Echocardiography was performed before and 2 months after infarction. Myocardial expression of transforming growth factor (TGF)-β1was determined by immunohistochemistry and fibrosis was evaluated by Sirius red staining. Results As compared with the baseline values in the control animals, left ventricular end-diastolic volume (from (19.5 5.1) to (32.3 5.6) ml, P <0.05) and end-systolic volume (from (8.3 3.2) to (15.2 4.1) ml, P <0.05) were significantly increased, whereas ejection fraction was decreased (from (61.6 13.3)% to (50.2 11.9)%, P<0.05). No obvious change in these parameters was observed in the sRAGE group. Myocardial expression of TGF-β1 was significantly elevated in the infarct and non-infarct regions in the control group, as compared with sRAGE group (both P<0.01). Fibrotic lesions were consistently more prominent in the infarct region of the myocardium in the control animals (P<0.05). Conclusion Intra-coronary sRAGE administration attenuates RAGE-mediated myocardial fibrosis and I/R injury through a TGF-β1-dependent mechanism, suggesting a clinical potential in treating RAGE/ligand-associated cardiovascular diseases.

  19. Transcriptional network analysis for the regulation of left ventricular hypertrophy and microvascular remodeling.

    Science.gov (United States)

    Moreno-Moral, Aida; Mancini, Massimiliano; D'Amati, Giulia; Camici, Paolo; Petretto, Enrico

    2013-12-01

    Hypertension and cardiomyopathies share maladaptive changes of cardiac morphology, eventually leading to heart failure. These include left ventricular hypertrophy (LVH), myocardial fibrosis, and structural remodeling of coronary microcirculation, which is the morphologic hallmark of coronary microvascular dysfunction. To pinpoint the complex molecular mechanisms and pathways underlying LVH-associated cardiac remodeling independent of blood pressure effects, we employed gene network approaches to the rat heart. We used the Spontaneously Hypertensive Rat model showing many features of human hypertensive cardiomyopathy, for which we collected histological and histomorphometric data of the heart and coronary vasculature, and genome-wide cardiac gene expression. Here, we provide a large catalogue of gene co-expression networks in the heart that are significantly associated with quantitative variation in LVH, microvascular remodeling, and fibrosis-related traits. Many of these networks were significantly conserved to human idiopathic and/or ischemic cardiomyopathy patients, suggesting a potential role for these co-expressed genes in human heart disease.

  20. Chromatin Remodeling and Plant Immunity.

    Science.gov (United States)

    Chen, W; Zhu, Q; Liu, Y; Zhang, Q

    2017-01-01

    Chromatin remodeling, an important facet of the regulation of gene expression in eukaryotes, is performed by two major types of multisubunit complexes, covalent histone- or DNA-modifying complexes, and ATP-dependent chromosome remodeling complexes. Snf2 family DNA-dependent ATPases constitute the catalytic subunits of ATP-dependent chromosome remodeling complexes, which accounts for energy supply during chromatin remodeling. Increasing evidence indicates a critical role of chromatin remodeling in the establishment of long-lasting, even transgenerational immune memory in plants, which is supported by the findings that DNA methylation, histone deacetylation, and histone methylation can prime the promoters of immune-related genes required for disease defense. So what are the links between Snf2-mediated ATP-dependent chromosome remodeling and plant immunity, and what mechanisms might support its involvement in disease resistance?

  1. Longstanding hyperthyroidism is associated with normal or enhanced intrinsic cardiomyocyte function despite decline in global cardiac function.

    Directory of Open Access Journals (Sweden)

    Nathan Y Weltman

    Full Text Available Thyroid hormones (THs play a pivotal role in cardiac homeostasis. TH imbalances alter cardiac performance and ultimately cause cardiac dysfunction. Although short-term hyperthyroidism typically leads to heightened left ventricular (LV contractility and improved hemodynamic parameters, chronic hyperthyroidism is associated with deleterious cardiac consequences including increased risk of arrhythmia, impaired cardiac reserve and exercise capacity, myocardial remodeling, and occasionally heart failure. To evaluate the long-term consequences of chronic hyperthyroidism on LV remodeling and function, we examined LV isolated myocyte function, chamber function, and whole tissue remodeling in a hamster model. Three-month-old F1b hamsters were randomized to control or 10 months TH treatment (0.1% grade I desiccated TH. LV chamber remodeling and function was assessed by echocardiography at 1, 2, 4, 6, 8, and 10 months of treatment. After 10 months, terminal cardiac function was assessed by echocardiography and LV hemodynamics. Hyperthyroid hamsters exhibited significant cardiac hypertrophy and deleterious cardiac remodeling characterized by myocyte lengthening, chamber dilatation, decreased relative wall thickness, increased wall stress, and increased LV interstitial fibrotic deposition. Importantly, hyperthyroid hamsters demonstrated significant LV systolic and diastolic dysfunction. Despite the aforementioned remodeling and global cardiac decline, individual isolated cardiac myocytes from chronically hyperthyroid hamsters had enhanced function when compared with myocytes from untreated age-matched controls. Thus, it appears that long-term hyperthyroidism may impair global LV function, at least in part by increasing interstitial ventricular fibrosis, in spite of normal or enhanced intrinsic cardiomyocyte function.

  2. Remodeling with the sun

    Energy Technology Data Exchange (ETDEWEB)

    Bodzin, S. [ed.

    1997-05-01

    Remodeling is the perfect time to improve daylighting, direct gain heating and shading with passive solar techniques. It can also provide the best opportunity to add solar water heating or even photoboltaics to a home. This article describes addition of such energy efficient plans to a home in terms of what is needed and what the benefits are: adding windows, North glass, east and west glass, south glass, daylighting, the roof, shingles and roofing tiles, walls and floors, solar hot water, photovoltaics. Two side bars discuss the sunplace: a passive solar room and angles and overhangs.

  3. Cardiac arrest

    Science.gov (United States)

    ... Article.jsp. Accessed June 16, 2014. Myerburg RJ, Castellanos A. Approach to cardiac arrest and life-threatening ... PA: Elsevier Saunders; 2011:chap 63. Myerburg RJ, Castellanos A. Cardiac arrest and audden aardiac death. In: ...

  4. 左旋卡尼汀在犬心房急性电重构中的抗氧化作用%Anti-oxidative stress effects of L-carnitine on acute atrial electrical re-modeling in dogs

    Institute of Scientific and Technical Information of China (English)

    官媛; 单兆亮; 郑强荪; 张晔; 郭红阳; 王玉堂

    2011-01-01

    目的:探讨左旋卡尼汀(L-carnitine,L-CN)抑制犬心房颤动(房颤)时心房急性电重构的作用机制.方法:18条成年杂种犬,随机分为生理盐水(NS)组、L-CN组和正常对照(normal control,NC)组.NS组予右心房600次/min快速起搏,诱发并维持房颤2 h;起搏前半小时静推生理盐水(300 mg/kg),继以液速50 ml/h维持静脉点滴2 h.L-CN组:右心房600 次/min快速起搏,诱发并维持房颤2 h,起搏前半小时静推L-CN(300 ms/kg),继以2.5mg/(kg·min)(液速50 ml/h)维持静脉点滴2 h.在不同观察时间点测定房颤前后电生理指标及静脉血氧化及抗氧化指标的变化.结果:①房颤后Ns组心房有效不应期(AERP)显著缩短(P<0.01),AERP的频率适应性显著下降(P<0.01);L-cN组房颤前后AERP和频率适应性无显著缩短;L-CN组较Ns组房颤诱发率明显降低(P<0.05).②NS组房颤时静脉血氧化应激产物较NC组显著增多(P<0.05),抗氧化指标显著下降(P<0.01).③L-CN组丙二醛(Malondialdehyd,MDA)生成显著减少(P<0.01),超氧化物歧化酶(superoxide dismutase,SOD)显著增加(P<0.05).结论:L-CN对房颤时氧化应激及电重构有明显保护作用,这种保护机制可能通过清除自由基,抑制脂质过氧化而发挥作用.%AIM: To evaluate the anti-oxidative stress effects of L-carnitine (L-CN) on tachycardiainduced acute atrial electrical remodeling in dogs. METHODS: Eighteen dogs were randomly divided into three groups: normal saline (NS) group, L-CN group and normal control (NC) group. In both NS and L-CN groups, right atrium was paced at 600 beats per minute (bpm) to induce atrial fibrillation (AF) and maintained for 2 h; 0. 9% normal saline (300 mg/kg, IV) or L-carnitine (300 mg/kg, IV)was given before the pace and 0.9% normal saline or L-carnitine [2.5 mg/(kg ·min), 50 ml/h, ID]was administered for 2 h. The observed atrial electrophysiology indexes included atrial effective refractory period (AERP), index of the AERP rate adaptation

  5. Influence of telmisartan on morning peak of blood pressure and cardiac remodeling in aged patients with hypertension%替米沙坦对老年高血压患者血压晨峰与心脏重构的影响

    Institute of Scientific and Technical Information of China (English)

    周咏梅; 陶剑虹

    2012-01-01

    目的:探讨替米沙坦对老年高血压患者血压晨峰现象及心脏重构的影响.方法:120例老年高血压患者根据血压晨峰是否超过23.58mmHg分为晨峰组(60例)与非晨峰组(60例),均予以替米沙坦80~160mg/d治疗6月,治疗前后行动态血压、心脏超声检查.结果:与血压非晨峰组比较,晨峰组左室肥厚发生率(36.7%比51.6%)、左房内径扩大率(26.7%比41.7%)明显升高(P均<0.01);与治疗前比较,晨峰组经替米沙坦治疗6月后收缩压(SBP)差值[(32.7±4.2) mmHg比(21.2±6.7) mmHg]、舒张压(DBP)差值[(20.3±3.6)mmHg比(13.5±7.4) mmHg]明显降低(P<0.01),而非晨峰组SBP、DBP差值较治疗前无明显降低(P>0.05),两组替米沙坦治疗6月后左室重量指数均明显降低(P<0.05).结论:老年高血压患者血压晨峰程度与心脏重构密切相关,替米沙坦能有效控制老年高血压患者晨峰现象,逆转左室肥厚.%Objective: To investigate influence of telmisartan on morning peak of blood pressure and cardiac remodeling in aged patients with hypertension. Methods: According to morning peak of blood pressure≥23. 58 mmHg or not, a total of 120 aged patients with hypertension were divided into morning peak of blood pressure group (observe group, n = 60) and non-morning peak of blood pressure group (control group, n = 60). Both groups received telmis-artan 80~160 mg/d for six months and underwent ambulatory blood pressure monitoring and echocardiography examination before and after treatment. Results: Compared with control group, incidence rates of left ventricular hypertrophy (36.7% vs. 51.6%) and left atrial enlargement rate (26.7% vs. 41.7%) significantly increased in observe group, P0. 05). After six- month telmisartan treatment, left ventricular mass indexes of the two groups significantly decreased (P<0. 05). Conclusion: Morning peak of blood pressure is closely correlated with cardiac remodeling in aged patients with hypertension

  6. A exposição crônica à fumaça do cigarro resulta em remodelação cardíaca e prejuízo da função ventricular em ratos Chronic cigarette smoke exposure results in cardiac remodeling and impaired ventricular function in rats

    Directory of Open Access Journals (Sweden)

    Édson Castardeli

    2005-04-01

    Full Text Available OBJETIVO: Determinar as alterações cardíacas estruturais e funcionais causadas pela exposição à fumaça do cigarro em ratos. MÉTODOS: Os animais foram aleatoriamente distribuídos em dois grupos: fumante (F, composto por 10 animais, expostos à fumaça do cigarro, na taxa de 40 cigarros/dia e controle (C, constituído por 10 animais não submetidos à exposição. Após 4 meses, os animais foram submetidos a estudo morfológico e funcional por meio do ecocardiograma. As variáveis estudadas foram analisadas pelo teste t ou pelo teste de Mann-Whitney. RESULTADOS: Os ratos fumantes apresentaram maior átrio esquerdo (F=4,2± 0,7mm; C=3,5±0,6mm; pOBJECTIVE: To determine the cardiac structural and functional alterations caused by cigarette smoke exposure in rats. METHODS: The animals were randomly distributed into the following 2 groups: 1 smokers (S, comprising 10 animals exposed to cigarette smoke at a rate of 40 cigarettes/day; and 2 control (C, comprising 10 animals not exposed to cigarette smoke. After 4 months, the animals underwent morphological and functional study with echocardiography. The variables studied were analyzed by use of the t test or the Mann-Whitney test. RESULTS: The smoking rats had a greater left atrium (S=4.2±0.7mm; C=3.5±0.6mm; P<0.05, and greater left ventricular diastolic (S=7.9±0.7mm; C=7.2±0.5mm; P<0.05 and systolic (S=4.1±0.5; C=3.4±0.5; P<0.05 diameters. The left ventricular mass index was greater in the smoking animals (S=1.5mg/kg±0.2; C=1.3mg/kg±0.2; P<0.05, and the ejection fraction (S=0.85±0.03; C=0.89±0.03; P<0.05 and the shortening fraction (S=47.8%±3.7; C=52.7%±4.6; P<0.05 were greater in the control group. No differences were observed in the diastolic transmitral flow variables (E wave, A wave, and E/A ratio. CONCLUSION: Chronic cigarette smoke exposure results in cardiac remodeling with a decrease in ventricular functional capacity.

  7. Electrical admittance for filling of the heart during lower body negative pressure in humans

    DEFF Research Database (Denmark)

    Cai, Yan; Holm, Søren; Jenstrup, Morten;

    2000-01-01

    cardiac output, electrical impedance, heart rate, positron emission tomography, technetium-labeled erythrocytes......cardiac output, electrical impedance, heart rate, positron emission tomography, technetium-labeled erythrocytes...

  8. To Remodel or To Build?

    Science.gov (United States)

    Rosenblum, Todd

    2009-01-01

    The question of remodeling an existing house to make it wheelchair accessible or building a new barrier-free house is a difficult decision. This article presents some initial questions and considerations followed by a list of pros and cons for remodeling an existing house vs. building a new house.

  9. No-Regrets Remodeling, 2nd Edition

    Energy Technology Data Exchange (ETDEWEB)

    None

    2013-12-01

    No-Regrets Remodeling, sponsored by Oak Ridge National Laboratory, is an informative publication that walks homeowners and/or remodelers through various home remodeling projects. In addition to remodeling information, the publication provides instruction on how to incorporate energy efficiency into the remodeling process. The goal of the publication is to improve homeowner satisfaction after completing a remodeling project and to provide the homeowner with a home that saves energy and is comfortable and healthy.

  10. Molecular mechanisms of remodeling in human atrial fibrillation

    NARCIS (Netherlands)

    Brundel, BJJM; Henning, RH; Kampinga, HH; Van Gelder, IC; Crijns, HJGM

    2002-01-01

    An important acknowledgement of the last several years is that atrial fibrillation (AF) modifies the electrical properties of the atrium in a way that promotes its occurrence and maintenance. This arrhythmogenic electrophysiological remodeling is well established, but can not explain by itself that

  11. Cardiac Electrophysiology: Normal and Ischemic Ionic Currents and the ECG

    Science.gov (United States)

    Klabunde, Richard E.

    2017-01-01

    Basic cardiac electrophysiology is foundational to understanding normal cardiac function in terms of rate and rhythm and initiation of cardiac muscle contraction. The primary clinical tool for assessing cardiac electrical events is the electrocardiogram (ECG), which provides global and regional information on rate, rhythm, and electrical…

  12. Cardiac applications of optogenetics.

    Science.gov (United States)

    Ambrosi, Christina M; Klimas, Aleksandra; Yu, Jinzhu; Entcheva, Emilia

    2014-08-01

    In complex multicellular systems, such as the brain or the heart, the ability to selectively perturb and observe the response of individual components at the cellular level and with millisecond resolution in time, is essential for mechanistic understanding of function. Optogenetics uses genetic encoding of light sensitivity (by the expression of microbial opsins) to provide such capabilities for manipulation, recording, and control by light with cell specificity and high spatiotemporal resolution. As an optical approach, it is inherently scalable for remote and parallel interrogation of biological function at the tissue level; with implantable miniaturized devices, the technique is uniquely suitable for in vivo tracking of function, as illustrated by numerous applications in the brain. Its expansion into the cardiac area has been slow. Here, using examples from published research and original data, we focus on optogenetics applications to cardiac electrophysiology, specifically dealing with the ability to manipulate membrane voltage by light with implications for cardiac pacing, cardioversion, cell communication, and arrhythmia research, in general. We discuss gene and cell delivery methods of inscribing light sensitivity in cardiac tissue, functionality of the light-sensitive ion channels within different types of cardiac cells, utility in probing electrical coupling between different cell types, approaches and design solutions to all-optical electrophysiology by the combination of optogenetic sensors and actuators, and specific challenges in moving towards in vivo cardiac optogenetics.

  13. Effects of multi-intervention RAAS on ventricular remodeling and serum K+ concentration in the chronic cardiac insufficiency rats%多重干预RAAS对大鼠慢性心功能不全心室重构及血钾的影响

    Institute of Scientific and Technical Information of China (English)

    陈斗佳; 陈娅; 吴伦宽

    2011-01-01

    目的 探讨多重干预RAAS对大鼠慢性心功能不全心室重构及血钾的影响.方法 实验采用缩窄大鼠腹主动脉法建立慢性压力负荷致心功能不全动物模型,选6周龄20只雌性SD大鼠,随机分4组(每组5只),B组(手术模型组)、C组(卡托普利组)、D组(卡托普利+缬沙坦组)、E组(卡托普利+缬沙坦+螺内酯组),另随机抽取5只同龄雌性SD大鼠假手术作为对照(A组).给药8周后用Doppler超声心动图检测大鼠心脏结构和心功能各项参数的变化,放射免疫法测定血浆Ang Ⅱ,ALDO浓度,并生化检测血钾水平.结果 腹主动脉结扎后第9周,与A组比较,B组舒张末期室间隔厚度(IVSTD)、舒张末期左室后壁厚度(LVPWTD)、相对室壁厚度(RWT)、左室重量(LVM)、左室重量与体重比(LVM/BW)均显著提高(P<0.05);C、D、E组与B组相比,LVM,LVM/BW下降显著(P<0.05).各药物干预组(C、D、E)血浆Ang Ⅱ,ALDO水平明显低于B组(P<0.05),以联合应用螺内酯组明显.各药物干预组与A组和B组相比较,血钾水平差异无显著性(P>0.05).结论 联合应用卡托普利、缬沙坦及螺内酯多重干预RAAS能明显改善大鼠慢性心功能不全心室重构,对血钾无明显影响.%Objective To explore the effects of multi-intervention RAAS on ventricular remodeling and serum K+ concentration in the chronic pressure overload heart due to cardiac insufficiency in rats. Methods To establish chronic cardiac insufficiency animal models with suprarenal abdominal aortic banding in rats. Six-week old female Sprague-Dawley rats were enrolled and the suprarenal abdominal aorta was ligated by 4-0 nylon suture against a needle (outer diameter 0. 7 mm). Twenty female rats were randomized into four groups (n = 5), including operated rats (group B), and Captopriltreated rats ( group C), Captopril + Valsartan treatment rats ( group D) and Captopril + Valsartan + Spironolactone treatment rats (group E), which were treated by

  14. Implantable defibrillators improve survival in patients with mildly symptomatic heart failure receiving cardiac resynchronization therapy

    DEFF Research Database (Denmark)

    Gold, Michael R; Daubert, Jean-Claude; Abraham, William T;

    2013-01-01

    Cardiac resynchronization therapy (CRT) decreases mortality, improves functional status, and induces reverse left ventricular remodeling in selected populations with heart failure. These benefits have been noted with both CRT-pacemakers as well as those devices with defibrillator backup (CRT...

  15. microRNA-21通过促进成纤维细胞的增殖和分化调节心肌梗死后的心脏重塑%MicroRNA-21 Regulates Cardiac Remodeling by Promoting Proliferation and Differentiation of Fibroblast after Myocardial Infarction

    Institute of Scientific and Technical Information of China (English)

    郭东; 张闽红; 肖清萍; 刘建文

    2014-01-01

    R-21 were measured by quantitative real-time PCR in the various myocardial tissues. The cardiac fibroblasts transfected with miR-21 mimic were over-expressed miR-21. The proliferation was assessed by immunostaining for 5-ethynyl-2’-deoxyuridine (EdU). Western blot assay was used to detect the expression ofα-SMA and Smad7 in the cardiac fibroblasts,and compared with control group and blank group. Results The expression of miR-21 was significantly increased in border area in MI group than that of sham group [(6.043 ± 0.231)×10-4 vs(1.620±0.451)×10-4,P<0.01]. There was a higher expression of miR-21 in miR-21 mimic group than that of control group and blank group [(4.839±0.705)×10-4 vs(1.143±0.064)×10-4 vs(1.017±0.201)×10-4,P<0.01]. The EdU positive rate was significantly higher in miR-21 mimic group than that of control group and blank group[(27.892±1.645)%vs(12.553 ± 1.227)% vs(13.946 ± 1.550)%,P<0.01]. The expression of α-SMA was significantly increased in miR-21 mimic group, while the expression of Smad7, a target gene of miR-21, was significantly decreased. Conclusion The over-expression of miR-21 in cardiac fibroblasts disrupts TGF-βsignaling pathway by reducing the expression of Smad7, which promotes the proliferation and differentiation of cardiac fibroblast, and finally regulates cardiac remodeling after myocardial infarction.

  16. Effects of valsartan on left ventricular remodeling and cardiac function in patients with essential hypertension using echocardiography with automated segmental motion analysis and free angle model%自动室壁分区运动分析与全方位M型超声心动图评价缬沙坦对高血压左心室重构及心脏整体功能的影响

    Institute of Scientific and Technical Information of China (English)

    赖小今; 梁燕; 朱峻; 陶杰; 陈重; 邓旦; 廖明松

    2010-01-01

    Objective To assess the effects of valsartan on left ventricular remodeling and cardiac functions in patients with essential hypertension using echocardiography with automated segmental motion analysis(ASMA)and free angle model(FAM).Methods The parameters about the cardiac morphology and function of the 178cases with essential hypertension were observed before and per three months(total about twelve months)after valsartan treated(80 mg/day)using echocardiography with ASMA-FAM,and the blood pressure values and patients' symptoms were observed at the same time.Results The patients' symptoms were improved,and the values of the patients blood pressure were decreased gradually after using valsartan two weeks,and they were to steady after five weeks.The values of left ventricle diameter,wall thickness,and left ventricular mass index were be decreased after treated six months(P<0.05),and they were be decreased obviously after treated one year(P<0.01),the left ventricular wall kinestate,cardiac functions were improved(P<0.01).Conclusions The left ventricular remodeling and the cardiac functions in patients with essential hypertension are improved obviously after using valsartan treated twelve months.The cardiac structures,left ventricle wall kinestate,and cardiac functions can be evaluated overall and objectively using echocardiography with ASMA-FAM.%目的 探讨自动室壁分区运动分析(ASMA)与全方位M型超声心动图(FAM)技术评价血管紧张素Ⅱ受体拮抗剂缬沙坦对原发性高血压左室重构及心脏整体功能的影响.方法 原发性高血压患者178例,应用缬沙坦80 mg/d口服治疗,疗程12个月.观察治疗过程中患者血压及症状体征的变化情况,并分别在治疗前及治疗后每3个月分阶段应用ASMA-FAM技术观察心脏形态学及心脏整体功能变化情况.结果 在治疗缬沙坦2周后血压开始下降,5周后趋于平稳;心腔径、室壁厚度及左室质量指数等在治疗3月后开始降低(P<0

  17. Over-phosphorylation of FKBP12.6, phospholamban,relating to exacerbation of cardiac arrhythmias and failure

    Institute of Scientific and Technical Information of China (English)

    De-zaiDAI

    2004-01-01

    AIM: Cardiac arrhythmias occur severely in diseased and failing hearts and remain an important cause of mortality in cardiovascular disorders. It was intended to explore mechanisms of abnormal ion channels underlying cardiac arrhythmias and failure and in responses to drug interventions. METHODS: Chronic infarction plus isoproterenol (ISO) medication or L-thyroxin (THY) repetitive medication promote cardiac remodeling and exaggerated

  18. Arrhythmogenesis in the remodeled heart : the role of spatially dispersed Cx43 expression

    NARCIS (Netherlands)

    Boulaksil, M.

    2010-01-01

    The heart is able to adapt to new, often pathologic, conditions, so-called cardiac remodeling. Although initially adequate, these adaptations could can become maladaptive over time. One of the adaptations of the heart during pathology is ventricular hypertrophy, which may go hand in hand with an inc

  19. Cardiac Sarcoidosis.

    Science.gov (United States)

    Birnie, David; Ha, Andrew C T; Gula, Lorne J; Chakrabarti, Santabhanu; Beanlands, Rob S B; Nery, Pablo

    2015-12-01

    Studies suggest clinically manifest cardiac involvement occurs in 5% of patients with pulmonary/systemic sarcoidosis. The principal manifestations of cardiac sarcoidosis (CS) are conduction abnormalities, ventricular arrhythmias, and heart failure. Data indicate that an 20% to 25% of patients with pulmonary/systemic sarcoidosis have asymptomatic (clinically silent) cardiac involvement. An international guideline for the diagnosis and management of CS recommends that patients be screened for cardiac involvement. Most studies suggest a benign prognosis for patients with clinically silent CS. Immunosuppression therapy is advocated for clinically manifest CS. Device therapy, with implantable cardioverter defibrillators, is recommended for some patients.

  20. Epigenetic mechanisms in cardiac development and disease

    Institute of Scientific and Technical Information of China (English)

    Marcus Vallaster; Caroline Dacwag Vallaster; Sean M. Wu

    2012-01-01

    During mammalian development,cardiac specification and ultimately lineage commitment to a specific cardiac cell type is accomplished by the action of specific transcription factors (TFs) and their meticulous control on an epigenetic level.In this review,we detail how cardiacspecific TFs function in concert with nucleosome remodeling and histone-modifying enzymes to regulate a diverse network of genes required for processes such as cell growth and proliferation,or epithelial to mesenchymal transition (EMT),for instance.We provide examples of how several cardiac TFs,such as Nkx2.5,WHSC1,Tbx5,and Tbx1,which are associated with developmental and congenital heart defects,are required for the recruitment of histone modifiers,such as Jarid2,p300,and Ash21,and components of ATP-dependent remodeling enzymes like Brg1,Baf60c,and Baf180.Binding of these TFs to their respective sites at cardiac genes coincides with a distinct pattern of histone marks,indicating that the precise regulation of cardiac gene networks is orchestrated by interactions between TFs and epigenetic modifiers.Furthermore,we speculate that an epigenetic signature,comprised of TF occupancy,histone modifications,and overall chromatin organization,is an underlying mechanism that governs cardiac morphogenesis and disease.

  1. Cardiac tissue engineering

    Directory of Open Access Journals (Sweden)

    MILICA RADISIC

    2005-03-01

    Full Text Available We hypothesized that clinically sized (1-5 mm thick,compact cardiac constructs containing physiologically high density of viable cells (~108 cells/cm3 can be engineered in vitro by using biomimetic culture systems capable of providing oxygen transport and electrical stimulation, designed to mimic those in native heart. This hypothesis was tested by culturing rat heart cells on polymer scaffolds, either with perfusion of culture medium (physiologic interstitial velocity, supplementation of perfluorocarbons, or with electrical stimulation (continuous application of biphasic pulses, 2 ms, 5 V, 1 Hz. Tissue constructs cultured without perfusion or electrical stimulation served as controls. Medium perfusion and addition of perfluorocarbons resulted in compact, thick constructs containing physiologic density of viable, electromechanically coupled cells, in contrast to control constructs which had only a ~100 mm thick peripheral region with functionally connected cells. Electrical stimulation of cultured constructs resulted in markedly improved contractile properties, increased amounts of cardiac proteins, and remarkably well developed ultrastructure (similar to that of native heart as compared to non-stimulated controls. We discuss here the state of the art of cardiac tissue engineering, in light of the biomimetic approach that reproduces in vitro some of the conditions present during normal tissue development.

  2. ANGPTL2 activity in cardiac pathologies accelerates heart failure by perturbing cardiac function and energy metabolism

    Science.gov (United States)

    Tian, Zhe; Miyata, Keishi; Kadomatsu, Tsuyoshi; Horiguchi, Haruki; Fukushima, Hiroyuki; Tohyama, Shugo; Ujihara, Yoshihiro; Okumura, Takahiro; Yamaguchi, Satoshi; Zhao, Jiabin; Endo, Motoyoshi; Morinaga, Jun; Sato, Michio; Sugizaki, Taichi; Zhu, Shunshun; Terada, Kazutoyo; Sakaguchi, Hisashi; Komohara, Yoshihiro; Takeya, Motohiro; Takeda, Naoki; Araki, Kimi; Manabe, Ichiro; Fukuda, Keiichi; Otsu, Kinya; Wada, Jun; Murohara, Toyoaki; Mohri, Satoshi; Yamashita, Jun K.; Sano, Motoaki; Oike, Yuichi

    2016-01-01

    A cardioprotective response that alters ventricular contractility or promotes cardiomyocyte enlargement occurs with increased workload in conditions such as hypertension. When that response is excessive, pathological cardiac remodelling occurs, which can progress to heart failure, a leading cause of death worldwide. Mechanisms underlying this response are not fully understood. Here, we report that expression of angiopoietin-like protein 2 (ANGPTL2) increases in pathologically-remodeled hearts of mice and humans, while decreased cardiac ANGPTL2 expression occurs in physiological cardiac remodelling induced by endurance training in mice. Mice overexpressing ANGPTL2 in heart show cardiac dysfunction caused by both inactivation of AKT and sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA)2a signalling and decreased myocardial energy metabolism. Conversely, Angptl2 knockout mice exhibit increased left ventricular contractility and upregulated AKT-SERCA2a signalling and energy metabolism. Finally, ANGPTL2-knockdown in mice subjected to pressure overload ameliorates cardiac dysfunction. Overall, these studies suggest that therapeutic ANGPTL2 suppression could antagonize development of heart failure. PMID:27677409

  3. Extracellular Matrix Remodeling During the Progression of Volume Overload-Induced Heart Failure

    Science.gov (United States)

    Hutchinson, Kirk R.; Stewart, James A.; Lucchesi, Pamela A.

    2009-01-01

    Volume overload-induced heart failure results in progressive left ventricular remodeling characterized by chamber dilation, eccentric cardiac myocyte hypertrophy and changes in extracellular matrix (ECM) remodeling changes. The ECM matrix scaffold is an important determinant of the structural integrity of the myocardium and actively participates in force transmission across the LV wall. In response to this hemodynamic overload, the ECM undergoes a distinct pattern of remodeling that differs from pressure overload. Once thought to be a static entity, the ECM is now regarded to be a highly adaptive structure that is dynamically regulated by mechanical stress, neurohormonal activation, inflammation and oxidative stress, that result in alterations in collagen and other matrix components and a net change in matrix metalloproteinase (MMP) expression and activation. These changes dictate overall ECM turnover during volume overload hear failure progression. This review will discuss the cellular and molecular mechanisms that dictate the temporal patterns of ECM remodeling during heart disease progression. PMID:19524591

  4. Cardiac Malpositions

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Shi Joon; Im, Chung Gie; Yeon, Kyung Mo; Hasn, Man Chung [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1979-06-15

    Cardiac Malposition refers to any position of the heart other than a left-sided heart in a situs solitus individual. Associated cardiac malformations are so complex that even angiocardiographic and autopsy studies may not afford an accurate information. Although the terms and classifications used to describe the internal cardiac anatomy and their arterial connections in cardiac malpositions differ and tend to be confusing, common agreement exists on the need for a segmental approach to diagnosis. Authors present 18 cases of cardiac malpositions in which cardiac catheterization and angiocardiography were done at the Department of Radiology, Seoul National University Hospital between 1971 and 1979. Authors analyzed the clinical, radiographic, operative and autopsy findings with the emphasis on the angiocardiographic findings. The results are as follows: 1. Among 18 cases with cardiac malpositions, 6 cases had dextrocardia with situs inversus, 9 cases had dextrocardia with situs solitus and 3 cases had levocardia with situs inversus. 2. There was no genuine exception to visceroatrial concordance rule. 3. Associated cardiac malpositions were variable and complex with a tendency of high association of transposition and double outlet varieties with dextrocardia in situs solitus and levocardia in situs inversus. Only one in 6 cases of dextrocardia with situs inversus had pure transposition. 4. In two cases associated pulmonary atresia was found at surgery which was not predicted by angiocardiography. 5. Because many of the associated complex lesions can be corrected surgically provided the diagnosis is accurate, the selective biplane angiocardiography with or without cineradiography is essential.

  5. 经胸微创封堵治疗对先天性心脏病患者心脏重构的近期影响%Short-term effect of minimally invasive transthoracic closure on cardiac remodeling in patients with congenital heart disease

    Institute of Scientific and Technical Information of China (English)

    王海永; 陈辉; 阳玉晶; 胡江苇; 李安桂; 杜振宗; 宋剑非

    2015-01-01

    transthoracic closure can effectively improve the short-term cardiac remodeling of patients with congenital heart disease.

  6. Extracellular matrix remodelling in myocardial hypertrophy and failure : focus on osteopontin.

    Science.gov (United States)

    Francia, Pietro; Uccellini, Arianna; Frattari, Alessandra; Modestino, Anna; Ricotta, Agnese; Balla, Cristina; Scialla, Ludovica; Volpe, Massimo

    2009-12-01

    Cardiac remodelling refers to molecular and cellular changes of the myocardium, as well as adapting alterations in size, shape and function of the heart in response to changing loading conditions. It represents the final common pathway of different heart diseases, and is recognized as a crucial aspect of cardiac and myocardial dysfunction and a well established determinant of the clinical course of heart failure.Osteopontin is an extracellular matrix glycoprotein secreted by osteoblasts, osteoclasts, macrophages, T cells, vascular smooth muscle cells, fibroblasts and cardiomyocytes. Osteopontin is not expressed in healthy cardiac tissue, although its expression can be triggered by pressure or volume overload, hypoxia and angiotensin II. Indeed, osteopontin has been reported in macrophages and interstitial tissues early after myocardial infarction and in cardiac macrophage-like cells of inflammatory lesions in experimental models of cardiomyopathy. Pressure overload is associated with osteopontin overexpression as well. Indeed, myocardial osteopontin messenger RNA is upregulated in rats following renovascular hypertension or aortic banding. In humans, a significant correlation exists between increased osteopontin immunoreactivity in cardiac myocytes and impaired left ventricular function or cardiomyocyte hypertrophy in patients with dilated cardiomyopathy.The present article focuses on the role of osteopontin in myocardial hypertrophy and remodelling. In general, evidence supports the concept that osteopontin plays a crucial role in extracellular matrix remodelling following myocardial adaptation to hypertrophic, inflammatory and neurohormonal stimuli in the overloaded heart.

  7. Combining experimental and mathematical modeling to reveal mechanisms of macrophage-dependent left ventricular remodeling

    Directory of Open Access Journals (Sweden)

    Dai Qiuxia

    2011-05-01

    Full Text Available Abstract Background Progressive remodeling of the left ventricle (LV following myocardial infarction (MI can lead to congestive heart failure, but the underlying initiation factors remain poorly defined. The objective of this study, accordingly, was to determine the key factors and elucidate the regulatory mechanisms of LV remodeling using integrated computational and experimental approaches. Results By examining the extracellular matrix (ECM gene expression and plasma analyte levels in C57/BL6J mice LV post-MI and ECM gene responses to transforming growth factor (TGF-β1 in cultured cardiac fibroblasts, we found that key factors in LV remodeling included macrophages, fibroblasts, transforming growth factor-β1, matrix metalloproteinase-9 (MMP-9, and specific collagen subtypes. We established a mathematical model to study LV remodeling post-MI by quantifying the dynamic balance between ECM construction and destruction. The mathematical model incorporated the key factors and demonstrated that TGF-β1 stimuli and MMP-9 interventions with different strengths and intervention times lead to different LV remodeling outcomes. The predictions of the mathematical model fell within the range of experimental measurements for these interventions, providing validation for the model. Conclusions In conclusion, our results demonstrated that the balance between ECM synthesis and degradation, controlled by interactions of specific key factors, determines the LV remodeling outcomes. Our mathematical model, based on the balance between ECM construction and destruction, provides a useful tool for studying the regulatory mechanisms and for predicting LV remodeling outcomes.

  8. Cardiac Imaging in Heart Failure with Comorbidities.

    Science.gov (United States)

    Wong, Chiew; Chen, Sylvia; Iyngkaran, Pupalan

    2017-01-01

    Imaging modalities stand at the frontiers for progress in congestive heart failure (CHF) screening, risk stratification and monitoring. Advancements in echocardiography (ECHO) and Magnetic Resonance Imaging (MRI) have allowed for improved tissue characterizations, cardiac motion analysis, and cardiac performance analysis under stress. Common cardiac comorbidities such as hypertension, metabolic syndromes and chronic renal failure contribute to cardiac remodeling, sharing similar pathophysiological mechanisms starting with interstitial changes, structural changes and finally clinical CHF. These imaging techniques can potentially detect changes earlier. Such information could have clinical benefits for screening, planning preventive therapies and risk stratifying patients. Imaging reports have often focused on traditional measures without factoring these novel parameters. This review is aimed at providing a synopsis on how we can use this information to assess and monitor improvements for CHF with comorbidities.

  9. Nanomaterials for Cardiac Myocyte Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Rodolfo Amezcua

    2016-07-01

    Full Text Available Since their synthesizing introduction to the research community, nanomaterials have infiltrated almost every corner of science and engineering. Over the last decade, one such field has begun to look at using nanomaterials for beneficial applications in tissue engineering, specifically, cardiac tissue engineering. During a myocardial infarction, part of the cardiac muscle, or myocardium, is deprived of blood. Therefore, the lack of oxygen destroys cardiomyocytes, leaving dead tissue and possibly resulting in the development of arrhythmia, ventricular remodeling, and eventual heart failure. Scarred cardiac muscle results in heart failure for millions of heart attack survivors worldwide. Modern cardiac tissue engineering research has developed nanomaterial applications to combat heart failure, preserve normal heart tissue, and grow healthy myocardium around the infarcted area. This review will discuss the recent progress of nanomaterials for cardiovascular tissue engineering applications through three main nanomaterial approaches: scaffold designs, patches, and injectable materials.

  10. The hearts of competitive athletes: an up-to-date overview of exercise-induced cardiac adaptations.

    Science.gov (United States)

    Dores, Hélder; Freitas, António; Malhotra, Aneil; Mendes, Miguel; Sharma, Sanjay

    2015-01-01

    Intense and regular physical exercise is responsible for various cardiac changes (electrical, structural and functional) that represent physiological adaptation to exercise training. This remodeling, commonly referred to as 'athlete's heart', can overlap with several pathological entities, in which sudden cardiac death may be the first clinical presentation. Although pre-competitive screening can identify athletes with life-threatening cardiovascular abnormalities, there are no widely used standardized pre-participation programs and those currently implemented are controversial. Data from personal and family history, features of physical examination and changes in the 12-lead electrocardiogram can raise the suspicion of cardiac disease and lead to early detection of entities such as hypertrophic cardiomyopathy. However, interpreting the electrocardiogram is often challenging, because some changes are considered physiological in athletes. Thus, clinical decision-making in such cases can prove difficult: missing a condition associated with an increased risk of life-threatening events, or conversely, mislabeling an athlete with a disease that leads to unnecessary disqualification, are both situations to avoid. This paper provides an up-to-date review of the physiological cardiac effects of exercise training and highlights key points that should be taken into consideration in the assessment of young competitive athletes.

  11. Zebrafish in the Study of Early Cardiac Development

    OpenAIRE

    Liu, Jiandong; Stainier, Didier Y.R.

    2012-01-01

    Heart development is a complex process that involves cell specification and differentiation, as well as elaborate tissue morphogenesis and remodeling, to generate a functional organ. The zebrafish has emerged as a powerful model system to unravel the basic genetic, molecular and cellular mechanisms of cardiac development and function. Here we summarize and discuss recent discoveries on early cardiac specification and the identification of the second heart field in zebrafish. In addition to th...

  12. CTGF knockout does not affect cardiac hypertrophy and fibrosis formation upon chronic pressure overload

    NARCIS (Netherlands)

    Fontes, Magda S C; Kessler, Elise L; van Stuijvenberg, Leonie; Brans, Maike A; Falke, LL; Kok, Bart; Leask, Andrew; van Rijen, HVM; Vos, MA; Goldschmeding, Roel; van Veen, AAB

    2015-01-01

    BACKGROUND: One of the main contributors to maladaptive cardiac remodeling is fibrosis. Connective tissue growth factor (CTGF), a matricellular protein that is secreted into the cardiac extracellular matrix by both cardiomyocytes and fibroblasts, is often associated with development of fibrosis. How

  13. Cardiac cameras.

    Science.gov (United States)

    Travin, Mark I

    2011-05-01

    Cardiac imaging with radiotracers plays an important role in patient evaluation, and the development of suitable imaging instruments has been crucial. While initially performed with the rectilinear scanner that slowly transmitted, in a row-by-row fashion, cardiac count distributions onto various printing media, the Anger scintillation camera allowed electronic determination of tracer energies and of the distribution of radioactive counts in 2D space. Increased sophistication of cardiac cameras and development of powerful computers to analyze, display, and quantify data has been essential to making radionuclide cardiac imaging a key component of the cardiac work-up. Newer processing algorithms and solid state cameras, fundamentally different from the Anger camera, show promise to provide higher counting efficiency and resolution, leading to better image quality, more patient comfort and potentially lower radiation exposure. While the focus has been on myocardial perfusion imaging with single-photon emission computed tomography, increased use of positron emission tomography is broadening the field to include molecular imaging of the myocardium and of the coronary vasculature. Further advances may require integrating cardiac nuclear cameras with other imaging devices, ie, hybrid imaging cameras. The goal is to image the heart and its physiological processes as accurately as possible, to prevent and cure disease processes.

  14. The effect of endotoxin on the controllability of cardiac rhythm in rats.

    Science.gov (United States)

    Mazloom, Roham; Shirazi, Amir H; Hajizadeh, Sohrab; Dehpour, Ahmad R; Mani, Ali R

    2014-03-01

    Decreased heart rate variability (HRV) has both diagnostic and prognostic value in patients with sepsis. However, it is not known whether reduced HRV in sepsis reflects an altered input from the autonomic nervous system or a remodeling of the cardiac pacemaker cells by inflammatory mediators. The present study aimed to investigate the effect of endotoxin on the heart rate dynamics of a denervated isolated heart in rats. Saline or endotoxin was injected into rats and their hearts were isolated and perfused. Atrial electrical activity was recorded and memory length in the time-series was assessed using inverse statistical analysis. Memory was defined as a statistical feature that lasts for a period of time and distinguishes the time-series from a random process. Endotoxaemic hearts exhibited a prolonged memory compared to the controls with respect to observing rare events. This indicates that a sudden decelerating event could potentially affect the cardiac rhythm of an endotoxaemic heart for a longer time than the controls. The prolongation of memory is indirectly linked to a reduced controllability in a complex system; therefore our data may provide evidence for a reduced controllability in cardiac rhythm following endotoxaemia.

  15. Toll-like receptor 4 activation promotes cardiac arrhythmias by decreasing the transient outward potassium current (Ito) through an IRF3-dependent and MyD88-independent pathway.

    Science.gov (United States)

    Monnerat-Cahli, Gustavo; Alonso, Hiart; Gallego, Monica; Alarcón, Micaela Lopez; Bassani, Rosana A; Casis, Oscar; Medei, Emiliano

    2014-11-01

    Cardiac arrhythmias are one of the main causes of death worldwide. Several studies have shown that inflammation plays a key role in different cardiac diseases and Toll-like receptors (TLRs) seem to be involved in cardiac complications. In the present study, we investigated whether the activation of TLR4 induces cardiac electrical remodeling and arrhythmias, and the signaling pathway involved in these effects. Membrane potential was recorded in Wistar rat ventricle. Ca(2+) transients, as well as the L-type Ca(2+) current (ICaL) and the transient outward K(+) current (Ito), were recorded in isolated myocytes after 24 h exposure to the TLR4 agonist, lipopolysaccharide (LPS, 1 μg/ml). TLR4 stimulation in vitro promoted a cardiac electrical remodeling that leads to action potential prolongation associated with arrhythmic events, such as delayed afterdepolarization and triggered activity. After 24 h LPS incubation, Ito amplitude, as well as Kv4.3 and KChIP2 mRNA levels were reduced. The Ito decrease by LPS was prevented by inhibition of interferon regulatory factor 3 (IRF3), but not by inhibition of interleukin-1 receptor-associated kinase 4 (IRAK4) or nuclear factor kappa B (NF-κB). Extrasystolic activity was present in 25% of the cells, but apart from that, Ca(2+) transients and ICaL were not affected by LPS; however, Na(+)/Ca(2+) exchanger (NCX) activity was apparently increased. We conclude that TLR4 activation decreased Ito, which increased AP duration via a MyD88-independent, IRF3-dependent pathway. The longer action potential, associated with enhanced Ca(2+) efflux via NCX, could explain the presence of arrhythmias in the LPS group.

  16. Transient Receptor Potential Channels Contribute to Pathological Structural and Functional Remodeling After Myocardial Infarction

    Science.gov (United States)

    Davis, Jennifer; Correll, Robert N.; Trappanese, Danielle M.; Hoffman, Nicholas E.; Troupes, Constantine D.; Berretta, Remus M.; Kubo, Hajime; Madesh, Muniswamy; Chen, Xiongwen; Gao, Erhe; Molkentin, Jeffery D.; Houser, Steven R.

    2014-01-01

    Rationale The cellular and molecular basis for post myocardial infarction (MI) structural and functional remodeling is not well understood. Objective To determine if Ca2+ influx through transient receptor potential (canonical) (TRPC) channels contributes to post-MI structural and functional remodeling. Methods and Results TRPC1/3/4/6 channel mRNA increased after MI in mice and was associated with TRPC-mediated Ca2+ entry. Cardiac myocyte specific expression of a dominant negative (dn: loss of function) TRPC4 channel increased basal myocyte contractility and reduced hypertrophy and cardiac structural and functional remodeling after MI while increasing survival. We used adenovirus-mediated expression of TRPC3/4/6 channels in cultured adult feline myocytes (AFMs) to define mechanistic aspects of these TRPC-related effects. TRPC3/4/6 over expression in AFMs induced calcineurin (Cn)-Nuclear Factor of Activated T cells (NFAT) mediated hypertrophic signaling, which was reliant on caveolae targeting of TRPCs. TRPC3/4/6 expression in AFMs increased rested state contractions and increased spontaneous sarcoplasmic reticulum (SR) Ca2+ sparks mediated by enhanced phosphorylation of the ryanodine receptor. TRPC3/4/6 expression was associated with reduced contractility and response to catecholamines during steady state pacing, likely due to enhanced SR Ca2+ leak. Conclusions Ca2+ influx through TRPC channels expressed after MI activates pathological cardiac hypertrophy and reduces contractility reserve. Blocking post-MI TRPC activity improved post-MI cardiac structure and function. PMID:25047165

  17. 人生长素对雌性大鼠心力衰竭心脏重塑及心肌细胞凋亡的影响%Effect of Human Ghrelin on the Cardiac Remodeling and Cardiomyocytes Apoptosis in Heart Failure Female Rats

    Institute of Scientific and Technical Information of China (English)

    孙宇泽; 李艳丽; 赵勇; 袁寰; 田国忠; 李梅秀

    2015-01-01

    Objective To study the effect of human ghrelin on morphosis and cardiomyocytes apoptosis in heart failure ( HF) rats derived from acute myocardial infarction ( AMI) , so as to explore the cardioprotective activity mechanism of growth hormone releasing-peptides( GHRPs) .Methods Under the monitoring of the electrocardiogram ( ECG) by the multichannel physiological signal collection management system to confirm successfully permanent ligation the left anterior descending coronary artery(LAD) to set up AMI model and then by ultrasound B system to rule out the rats without HF or to make the sham group rats which merely pass through the stylolite beneeth LAD;HF model group rats accept three weeks human ghrelin through tail vein injection, using HE stain technique to analyze the changes of morphosis , the cardiomyocytes apoptosis in HF rats were assessed by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling( TUNEL) .Results TUNEL staining results showed that the cardiomyocytes in rats after permanent LAD ligation aligned ex-tremely irregularly, granular degeneration,swelling,much karyopyknosis and severe interstitial fibrosis,inflammatory cell infiltrate,while in human ghrelin intervention rats, cardiaomyocytes aligned irregularly,swelling and granular degeneration also could be found but without typical karyopyknosis or severe interstitial fibrosis.The cardiomyocytes apoptotic index in HF group rats is significantly higher than that in ghrelin intervention group rats(P<0.05).Conclusion Extrinsic human ghrelin exerted the cardioprotective activities by reducing the cardiomyocytes apoptosis and inhabitting the cardiac remodeling.%目的:研究人ghrelin对急性心肌梗死( acute myocardial infarction,AMI)致心力衰竭( heart failure,HF)大鼠心肌形态结构变化和心肌细胞凋亡的影响,探索生长素释放肽( growth hormone releasing-peptides,GHRPs)心脏保护活性机制。方法经心电图监测成功永久结

  18. Eccentric and concentric cardiac hypertrophy induced by exercise training: microRNAs and molecular determinants

    OpenAIRE

    Fernandes, T.; Soci, U.P.R.; E.M. Oliveira

    2011-01-01

    Among the molecular, biochemical and cellular processes that orchestrate the development of the different phenotypes of cardiac hypertrophy in response to physiological stimuli or pathological insults, the specific contribution of exercise training has recently become appreciated. Physiological cardiac hypertrophy involves complex cardiac remodeling that occurs as an adaptive response to static or dynamic chronic exercise, but the stimuli and molecular mechanisms underlying transduction of th...

  19. Postmyocardial Infarct Remodeling and Heart Failure: Potential Contributions from Pro- and Antiaging Factors

    Directory of Open Access Journals (Sweden)

    Halliday A. Idikio

    2011-01-01

    Full Text Available Myocardial infarction and adverse postinfarct remodeling in older persons lead to poor outcome and need greater understanding of the contributions of age-related factors on abnormal cardiac function and management. In this perspective, how normal aging processes could contribute to the events of post-myocardial infarction and remodeling is reviewed. Post-myocardial infarction and remodeling involve cardiomechanical factors and neurohormonal response. Many factors prevent or accelerate aging including immunosenescence, recruitment and regeneration of stem cells, telomere shortening, oxidative damage, antiaging hormones klotho and melatonin, nutrition, and Sirtiun protein family, and these factors could affect post-MI remodeling and heart failure. Interest in stem cell repair of myocardial infarcts to mitigate post-MI remodeling needs more information on aging of stem cells, and potential effects on stem cell use in infarct repair. Integrating genomics and proteomics methods may help find clinically novel therapy in the management of post-MI remodeling and heart failure in aged individuals.

  20. Biomarkers to Predict Reverse Remodeling and Myocardial Recovery in Heart Failure.

    Science.gov (United States)

    Motiwala, Shweta R; Gaggin, Hanna K

    2016-10-01

    Left ventricular remodeling appears to be a critical link between cardiac injury and the development and progression of heart failure with reduced ejection fraction (HFrEF). Several drug and device therapies that modify and reverse the remodeling process in patients with HFrEF are closely associated with improvement in clinical outcomes. Reverse remodeling, including partial or complete recovery of systolic function and structure, is possible but its determinants are incompletely understood. Methods to predict reverse remodeling in response to therapy are not well defined. Though non-invasive imaging techniques remain the most widely used methods of assessing reverse remodeling, serum biomarkers are now being investigated as more specific, mechanistically driven, and clinically useful predictors of reverse remodeling. Biomarkers that reflect myocyte stretch and stress, myocyte injury and necrosis, inflammation and fibrosis, and extracellular matrix turnover may be particularly valuable for predicting pathophysiologic changes and prognosis in individual patients. Their use may ultimately allow improved application of precision medicine in chronic HF.

  1. Cardiac echinococcosis

    Directory of Open Access Journals (Sweden)

    Ivanović-Krstić Branislava A.

    2002-01-01

    Full Text Available Cardiac hydatid disease is rare. We report on an uncommon hydatid cyst localized in the right ventricular wall, right atrial wall tricuspid valve left atrium and pericard. A 33-year-old woman was treated for cough, fever and chest pain. Cardiac echocardiograpic examination revealed a round tumor (5.8 x 4 cm in the right ventricular free wall and two smaller cysts behind that tumor. There were cysts in right atrial wall and tricuspidal valve as well. Serologic tests for hydatidosis were positive. Computed tomography finding was consistent with diagnosis of hydatid cyst in lungs and right hylar part. Surgical treatment was rejected due to great risk of cardiac perforation. Medical treatment with albendazole was unsuccessful and the patient died due to systemic hydatid involvement of the lungs, liver and central nervous system.

  2. Observation of functional remodeling of Ca2+-activated Cl- channel in pacing-induced canine failing heart

    Institute of Scientific and Technical Information of China (English)

    浦介麟

    2006-01-01

    Objective To study whether Ca2+-activated Cl-current (Ito2) contributes to the functional remodeling of the failing heart. Methods The cardiac myocytes were isolated enzymatically from rapidly pacing-induced failing canine hearts (HF) at room temperature. Patch-Clamp whole cell recording technique was employed to record the Ito2.The Cl- transport blocker 4,4’-diisothiocyanos-

  3. Cardiac Rehabilitation

    Science.gov (United States)

    ... your risk of future heart problems, and to improve your health and quality of life. Cardiac rehabilitation programs increase ... exercise routine at home or at a local gym. You may also continue to ... health concerns. Education about nutrition, lifestyle and weight loss ...

  4. Vascular Remodeling in Experimental Hypertension

    Directory of Open Access Journals (Sweden)

    Norma R. Risler

    2005-01-01

    Full Text Available The basic hemodynamic abnormality in hypertension is an increased peripheral resistance that is due mainly to a decreased vascular lumen derived from structural changes in the small arteries wall, named (as a whole vascular remodeling. The vascular wall is an active, flexible, and integrated organ made up of cellular (endothelial cells, smooth muscle cells, adventitia cells, and fibroblasts and noncellular (extracellular matrix components, which in a dynamic way change shape or number, or reorganize in response to physiological and pathological stimuli, maintaining the integrity of the vessel wall in physiological conditions or participating in the vascular changes in cardiovascular diseases such as hypertension. Research focused on new signaling pathways and molecules that can participate in the mechanisms of vascular remodeling has provided evidence showing that vascular structure is not only affected by blood pressure, but also by mechanisms that are independent of the increased pressure. This review will provide an overview of the evidence, explaining some of the pathophysiologic mechanisms participating in the development of the vascular remodeling, in experimental models of hypertension, with special reference to the findings in spontaneously hypertensive rats as a model of essential hypertension, and in fructose-fed rats as a model of secondary hypertension, in the context of the metabolic syndrome. The understanding of the mechanisms producing the vascular alterations will allow the development of novel pharmacological tools for vascular protection in hypertensive disease.

  5. Geschlechterunterschiede beim kardialen Remodeling der extrazellulären Matrix durch Laufradtraining und Myokardinfarkt im Mausmodell

    OpenAIRE

    Ehrenberg, Nadine

    2010-01-01

    Cardiovascular diseases, especially the myocardial infarction, are the major cause of death in industrialized countries. Incidence and mortality show obvious gender-differences. Until menopause, women rarely have myocardial infarctions and mortality is also low. Postmeno-pausal however, the risk adapts quite fast and incidence and mortality rise. The reasons for the higher mortality in males are at least in the mouse model more fatal cardiac adaptations in extracellular matrix remodeling. Mal...

  6. Large cardiac fibroma and teratoma in children- case reports.

    Science.gov (United States)

    Jha, Neerod Kumar; Kiraly, Laszlo; Tamas, Csaba; Talo, Haitham; Khan, Mohammad Daud; El Badaoui, Hazem; Jain, Anurag; Hammad, Azzam

    2015-03-22

    Primary cardiac tumours in paediatric population are an unusual occurrence. Although, majority of such tumours are benign (90%), the frequency and type of cardiac tumours in this age group is different from the adult population. There are several consecutive series published in the last decade on cardiac neoplasms. Therefore, this is not only an effort to contribute to the existing literature for better understanding and management of similar patients but also to highlight the importance of early detection either by prenatal imaging or careful evaluation of differential diagnosis of common symptoms. We herein, describe two infants with large cardiac tumours (fibroma and teratoma) both arising from the interventricular septum and underwent surgical excision. A possible role of cardiac remodeling in myocardial tissue healing after extensive tissue resection in such patients is hypothesised through available experimental or limited clinical information.

  7. Cardiac resynchronization therapy pacemaker: critical appraisal of the adaptive CRT-P device

    Directory of Open Access Journals (Sweden)

    Daoud GE

    2016-01-01

    Full Text Available Georges E Daoud,1 Mahmoud Houmsse2 1Department of the Biomedical Research, 2Division of Cardiovascular Medicine, The Ohio State University Wexner Medical Center, Columbus, OH, USA Abstract: Cardiac resynchronization therapy (CRT is an effective and well-established therapy for patients suffering with heart failure, left ventricular (LV systolic dysfunction (ejection fraction ≤35%, and electrical dyssynchrony, demonstrated by a surface QRS duration of ≥120 ms. Patients undergoing treatment with CRT have shown significant improvement in functional class, quality of life, LV ejection fraction, exercise capacity, hemodynamics, and reverse remodeling of LV, and ultimately, morbidity and mortality. However, 30%–40% of patients who receive a CRT device may not show improvement, and they are termed as nonresponders. The nonresponders have a poor prognosis; several methods have been developed to try to enhance response to CRT. Echocardiography-guided optimization of CRT has not resulted in significant clinical benefit, since it is done at rest with the patient in supine position. An ideal optimization strategy would provide continuous monitoring and adjustment of device pacing to provide maximal cardiac resynchronization, under a multitude of physiologic states. Intrinsic activation of the right ventricle (RV with paced activation of the RV, even in the setting of biventricular (BiV pacing, may result in an adverse effect on cardiac performance. With this physiology, the use of LV-only pacing may be preferred and may enhance CRT. Adaptive CRT is a novel device-based algorithm that was designed to achieve patient-specific adjustment in CRT so as to provide appropriate BiV pacing or LV-only pacing. This article will review the goals of CRT optimization, and implementation and outcomes associated with adaptive CRT. Keywords: heart failure, cardiac resynchronization, therapy, adaptive, left and biventricular pacing

  8. Molecular pathogenesis of myocardial remodeling and new potential therapeutic targets in chronic heart failure

    Directory of Open Access Journals (Sweden)

    Distefano Giuseppe

    2012-09-01

    Full Text Available Abstract It is well known that the natural history of chronic heart failure (CHF,regardless of age and aetiology,is characterized by progressive cardiac dysfunction refractory to conventional cardiokinetic, diuretic and peripheral vasodilator therapy. Several previous studies, both in animals and humans, showed that the key pathogenetic element of CHF negative clinical evolution is constituted by myocardial remodeling. This is a complex pathologic process of ultrastructural rearrangement of the heart induced by various neuro-humoral factors released by cardiac fibrocells in response to biomechanical stress connected to chronic haemodynamic overload. Typical features of myocardial remodeling are represented by cardiomyocytes hypertrophy and apoptosis, extracellular matrix alterations, mesenchymal fibrotic and phlogistic processes and by cardiac gene expression modifications with fetal genetic program reactivation. In the last years, increasing knowledge of subtle molecular and cellular mechanisms involved in myocardial remodeling has led to the discovery of some new potential therapeutic targets capable of inducing its regression. In this paper our attention is focused on the possible use of antiapoptotic and antifibrotic agents, and on the fascinating perspectives offered by the development of myocardial gene therapy and, in particular, by myocardial regenerative therapy.

  9. Molecular pathogenesis of myocardial remodeling and new potential therapeutic targets in chronic heart failure.

    Science.gov (United States)

    Distefano, Giuseppe; Sciacca, Pietro

    2012-09-12

    It is well known that the natural history of chronic heart failure (CHF),regardless of age and aetiology,is characterized by progressive cardiac dysfunction refractory to conventional cardiokinetic, diuretic and peripheral vasodilator therapy. Several previous studies, both in animals and humans, showed that the key pathogenetic element of CHF negative clinical evolution is constituted by myocardial remodeling. This is a complex pathologic process of ultrastructural rearrangement of the heart induced by various neuro-humoral factors released by cardiac fibrocells in response to biomechanical stress connected to chronic haemodynamic overload. Typical features of myocardial remodeling are represented by cardiomyocytes hypertrophy and apoptosis, extracellular matrix alterations, mesenchymal fibrotic and phlogistic processes and by cardiac gene expression modifications with fetal genetic program reactivation. In the last years, increasing knowledge of subtle molecular and cellular mechanisms involved in myocardial remodeling has led to the discovery of some new potential therapeutic targets capable of inducing its regression. In this paper our attention is focused on the possible use of antiapoptotic and antifibrotic agents, and on the fascinating perspectives offered by the development of myocardial gene therapy and, in particular, by myocardial regenerative therapy.

  10. Cardiac Calcification

    Directory of Open Access Journals (Sweden)

    Morteza Joorabian

    2011-05-01

    Full Text Available There is a spectrum of different types of cardiac"ncalcifications with the importance and significance"nof each type of cardiac calcification, especially"ncoronary artery calcification. Radiologic detection of"ncalcifications within the heart is quite common. The"namount of coronary artery calcification correlates"nwith the severity of coronary artery disease (CAD."nCalcification of the aortic or mitral valve may indicate"nhemodynamically significant valvular stenosis."nMyocardial calcification is a sign of prior infarction,"nwhile pericardial calcification is strongly associated"nwith constrictive pericarditis. A spectrum of different"ntypes of cardiac calcifications (linear, annular,"ncurvilinear,... could be seen in chest radiography and"nother imaging modalities. So a carful inspection for"ndetection and reorganization of these calcifications"nshould be necessary. Numerous modalities exist for"nidentifying coronary calcification, including plain"nradiography, fluoroscopy, intravascular ultrasound,"nMRI, echocardiography, and conventional, helical and"nelectron-beam CT (EBCT. Coronary calcifications"ndetected on EBCT or helical CT can be quantifie,"nand a total calcification score (Cardiac Calcification"nScoring may be calculated. In an asymptomatic"npopulation and/or patients with concomitant risk"nfactors like diabetes mellitus, determination of the"npresence of coronary calcifications identifies the"npatients at risk for future myocardial infarction and"ncoronary artery disease. In patients without coronary"ncalcifications, future cardiovascular events could"nbe excluded. Therefore, detecting and recognizing"ncalcification related to the heart on chest radiography"nand other imaging modalities such as fluoroscopy, CT"nand echocardiography may have important clinical"nimplications.

  11. Mechanisms involving Ang II and MAPK/ERK1/2 signaling pathways underlie cardiac and renal alterations during chronic undernutrition.

    Directory of Open Access Journals (Sweden)

    Paulo A Silva

    Full Text Available Several studies have correlated protein restriction associated with other nutritional deficiencies with the development of cardiovascular and renal diseases. The driving hypothesis for this study was that Ang II signaling pathways in the heart and kidney are affected by chronic protein, mineral and vitamin restriction.Wistar rats aged 90 days were fed from weaning with either a control or a deficient diet that mimics those used in impoverished regions worldwide. Such restriction simultaneously increased ouabain-insensitive Na+-ATPase and decreased (Na++K+ATPase activity in the same proportion in cardiomyocytes and proximal tubule cells. Type 1 angiotensin II receptor (AT1R was downregulated by that restriction in both organs, whereas AT2R decreased only in the kidney. The PKC/PKA ratio increased in both tissues and returned to normal values in rats receiving Losartan daily from weaning. Inhibition of the MAPK pathway restored Na+-ATPase activity in both organs. The undernourished rats presented expanded plasma volume, increased heart rate, cardiac hypertrophy, and elevated systolic pressure, which also returned to control levels with Losartan. Such restriction led to electrical cardiac remodeling represented by prolonged ventricular repolarization parameters, induced triggered activity, early after-depolarization and delayed after-depolarization, which were also prevented by Losartan.The mechanisms responsible for these alterations are underpinned by an imbalance in the PKC- and PKA-mediated pathways, with participation of angiotensin receptors and by activation of the MAPK/ERK1/2 pathway. These cellular and molecular alterations culminate in cardiac electric remodeling and in the onset of hypertension in adulthood.

  12. Physics of Cardiac Arrhythmogenesis

    Science.gov (United States)

    Karma, Alain

    2013-04-01

    A normal heartbeat is orchestrated by the stable propagation of an excitation wave that produces an orderly contraction. In contrast, wave turbulence in the ventricles, clinically known as ventricular fibrillation (VF), stops the heart from pumping and is lethal without prompt defibrillation. I review experimental, computational, and theoretical studies that have shed light on complex dynamical phenomena linked to the initiation, maintenance, and control of wave turbulence. I first discuss advances made to understand the precursor state to a reentrant arrhythmia where the refractory period of cardiac tissue becomes spatiotemporally disordered; this is known as an arrhythmogenic tissue substrate. I describe observed patterns of transmembrane voltage and intracellular calcium signaling that can contribute to this substrate, and symmetry breaking instabilities to explain their formation. I then survey mechanisms of wave turbulence and discuss novel methods that exploit electrical pacing stimuli to control precursor patterns and low-energy pulsed electric fields to control turbulence.

  13. Mesenchymal stem cells with overexpression of midkine enhance cell survival and attenuate cardiac dysfunction in a rat model of myocardial infarction

    NARCIS (Netherlands)

    S.-L. Zhao (Shu-Li); Y. Zhang (Yaojun); M.-H. Li (Ming-Hui); X.-L. Zhang (Xin-Lei); S.-L. Chen (Shao-Liang)

    2014-01-01

    textabstractIntroduction. Elevated midkine (MK) expression may contribute to ventricular remodeling and ameliorate cardiac dysfunction after myocardial infarction (MI). Ex vivo modification of signaling mechanisms in mesenchymal stem cells (MSCs) with MK overexpression may improve the efficacy of ce

  14. Quantitative analysis of cardiac tissue including fibroblasts using three-dimensional confocal microscopy and image reconstruction: towards a basis for electrophysiological modeling

    NARCIS (Netherlands)

    Schwab, Bettina C.; Seemann, Gunnar; Lasher, Richard A.; Torres, Natalia S.; Wülfers, Eike M.; Arp, Maren; Carruth, Eric D.; Bridge, John H.B.; Sachse, Frank B.

    2013-01-01

    Electrophysiological modeling of cardiac tissue is commonly based on functional and structural properties measured in experiments. Our knowledge of these properties is incomplete, in particular their remodeling in disease. Here, we introduce a methodology for quantitative tissue characterization bas

  15. The need to immobilise the cervical spine during cardiopulmonary resuscitation and electric shock administration in out-of-hospital cardiac arrest.

    Science.gov (United States)

    Desroziers, Milene; Mole, Sophie; Jost, Daniel; Tourtier, Jean-Pierre

    2016-06-13

    In cases of out-of hospital cardiac arrest (OHCA), falling to the ground can cause brain and neck trauma to the patient. We present a case of a man in his mid-60s who suffered from an OHCA resulting in a violent collapse. The patient received immediate cardiopulmonary resuscitation, but his spine was immobilised only after a large frontal haematoma was found. The resuscitation efforts resulted in return of spontaneous circulation and discharge from hospital. After this, doctors performed angioplasty, followed by a cardiopulmonary bypass. Later, CT scan examination reported a displaced and unstable fracture of the 6th vertebra without bone marrow involvement. The patient underwent a second operation. 40 days later, he was able to return home without sequela. This case shows the importance of analysing the circumstances of a fall, considering the possibility of two concomitant diagnoses and prioritising investigations and treatment.

  16. Antiarrhythmic effect of growth factor-supplemented cardiac progenitor cells in chronic infarcted heart.

    Science.gov (United States)

    Savi, Monia; Bocchi, Leonardo; Rossi, Stefano; Frati, Caterina; Graiani, Gallia; Lagrasta, Costanza; Miragoli, Michele; Di Pasquale, Elisa; Stirparo, Giuliano G; Mastrototaro, Giuseppina; Urbanek, Konrad; De Angelis, Antonella; Macchi, Emilio; Stilli, Donatella; Quaini, Federico; Musso, Ezio

    2016-06-01

    c-Kit(pos) cardiac progenitor cells (CPCs) represent a successful approach in healing the infarcted heart and rescuing its mechanical function, but electrophysiological consequences are uncertain. CPC mobilization promoted by hepatocyte growth factor (HGF) and IGF-1 improved electrogenesis in myocardial infarction (MI). We hypothesized that locally delivered CPCs supplemented with HGF + IGF-1 (GFs) can concur in ameliorating electrical stability of the regenerated heart. Adult male Wistar rats (139 rats) with 4-wk-old MI or sham conditions were randomized to receive intramyocardial injection of GFs, CPCs, CPCs + GFs, or vehicle (V). Enhanced green fluorescent protein-tagged CPCs were used for cell tracking. Vulnerability to stress-induced arrhythmia was assessed by telemetry-ECG. Basic cardiac electrophysiological properties were examined by epicardial multiple-lead recording. Hemodynamic function was measured invasively. Hearts were subjected to anatomical, morphometric, immunohistochemical, and molecular biology analyses. Compared with V and at variance with individual CPCs, CPCs + GFs approximately halved arrhythmias in all animals, restoring cardiac anisotropy toward sham values. GFs alone reduced arrhythmias by less than CPCs + GFs, prolonging ventricular refractoriness without affecting conduction velocity. Concomitantly, CPCs + GFs reactivated the expression levels of Connexin-43 and Connexin-40 as well as channel proteins of key depolarizing and repolarizing ion currents differently than sole GFs. Mechanical function and anatomical remodeling were equally improved by all regenerative treatments, thus exhibiting a divergent behavior relative to electrical aspects. Conclusively, we provided evidence of distinctive antiarrhythmic action of locally injected GF-supplemented CPCs, likely attributable to retrieval of Connexin-43, Connexin-40, and Cav1.2 expression, favoring intercellular coupling and spread of excitation in mended heart.

  17. Tricuspid annular plane systolic excursion and response to cardiac resynchronization therapy

    DEFF Research Database (Denmark)

    Kjaergaard, Jesper; Ghio, Stefano; St John Sutton, Martin;

    2011-01-01

    The aims of this study were to evaluate tricuspid annular plane systolic excursion (TAPSE) as a predictor of left ventricular (LV) reverse remodeling and clinical benefit of cardiac synchronization therapy (CRT) and to evaluate the effect of CRT on TAPSE in patients with mildly symptomatic systolic...... heart failure as a substudy of the REsyncronization reVErses Remodeling in Systolic left vEntricular dysfunction (REVERSE) trial....

  18. Electrophysiological Cardiac Modeling: A Review.

    Science.gov (United States)

    Beheshti, Mohammadali; Umapathy, Karthikeyan; Krishnan, Sridhar

    2016-01-01

    Cardiac electrophysiological modeling in conjunction with experimental and clinical findings has contributed to better understanding of electrophysiological phenomena in various species. As our knowledge on underlying electrical, mechanical, and chemical processes has improved over time, mathematical models of the cardiac electrophysiology have become more realistic and detailed. These models have provided a testbed for various hypotheses and conditions that may not be easy to implement experimentally. In addition to the limitations in experimentally validating various scenarios implemented by the models, one of the major obstacles for these models is computational complexity. However, the ever-increasing computational power of supercomputers facilitates the clinical application of cardiac electrophysiological models. The potential clinical applications include testing and predicting effects of pharmaceutical agents and performing patient-specific ablation and defibrillation. A review of studies involving these models and their major findings are provided.

  19. Local heterogeneities in cardiac systems suppress turbulence by generating multi-armed rotors

    Science.gov (United States)

    Zhang, Zhihui; Steinbock, Oliver

    2016-05-01

    Ventricular fibrillation is an extremely dangerous cardiac arrhythmia that is linked to rotating waves of electric activity and chaotically moving vortex lines. These filaments can pin to insulating, cylindrical heterogeneities which swiftly become the new rotation backbone of the local wave field. For thin cylinders, the stabilized rotation is sufficiently fast to repel the free segments of the turbulent filament tangle and annihilate them at the system boundaries. The resulting global wave pattern is periodic and highly ordered. Our cardiac simulations show that also thicker cylinders can establish analogous forms of tachycardia. This process occurs through the spontaneous formation of pinned multi-armed vortices. The observed number of wave arms N depends on the cylinder radius and is associated to stability windows that for N = 2, 3 partially overlap. For N = 1, 2, we find a small gap in which the turbulence is removed but the pinned rotor shows complex temporal dynamics. The relevance of our findings to human cardiology are discussed in the context of vortex pinning to more complex-shaped anatomical features and remodeled myocardium.

  20. Cardiac fluid dynamics anticipates heart adaptation.

    Science.gov (United States)

    Pedrizzetti, Gianni; Martiniello, Alfonso R; Bianchi, Valter; D'Onofrio, Antonio; Caso, Pio; Tonti, Giovanni

    2015-01-21

    Hemodynamic forces represent an epigenetic factor during heart development and are supposed to influence the pathology of the grown heart. Cardiac blood motion is characterized by a vortical dynamics, and it is common belief that the cardiac vortex has a role in disease progressions or regression. Here we provide a preliminary demonstration about the relevance of maladaptive intra-cardiac vortex dynamics in the geometrical adaptation of the dysfunctional heart. We employed an in vivo model of patients who present a stable normal heart function in virtue of the cardiac resynchronization therapy (CRT, bi-ventricular pace-maker) and who are expected to develop left ventricle remodeling if pace-maker was switched off. Intra-ventricular fluid dynamics is analyzed by echocardiography (Echo-PIV). Under normal conditions, the flow presents a longitudinal alignment of the intraventricular hemodynamic forces. When pacing is temporarily switched off, flow forces develop a misalignment hammering onto lateral walls, despite no other electro-mechanical change is noticed. Hemodynamic forces result to be the first event that evokes a physiological activity anticipating cardiac changes and could help in the prediction of longer term heart adaptations.

  1. Vascular Remodelling and Mesenchymal Transition in Systemic Sclerosis

    Directory of Open Access Journals (Sweden)

    Pier Andrea Nicolosi

    2016-01-01

    Full Text Available Fibrosis of the skin and of internal organs, autoimmunity, and vascular inflammation are hallmarks of Systemic Sclerosis (SSc. The injury and activation of endothelial cells, with hyperplasia of the intima and eventual obliteration of the vascular lumen, are early features of SSc. Reduced capillary blood flow coupled with deficient angiogenesis leads to chronic hypoxia and tissue ischemia, enforcing a positive feed-forward loop sustaining vascular remodelling, further exacerbated by extracellular matrix accumulation due to fibrosis. Despite numerous developments and a growing number of controlled clinical trials no treatment has been shown so far to alter SSc natural history, outlining the need of further investigation in the molecular pathways involved in the pathogenesis of the disease. We review some processes potentially involved in SSc vasculopathy, with attention to the possible effect of sustained vascular inflammation on the plasticity of vascular cells. Specifically we focus on mesenchymal transition, a key phenomenon in the cardiac and vascular development as well as in the remodelling of injured vessels. Recent work supports the role of transforming growth factor-beta, Wnt, and Notch signaling in these processes. Importantly, endothelial-mesenchymal transition may be reversible, possibly offering novel cues for treatment.

  2. Anti-remodeling effects of rapamycin in experimental heart failure: dose response and interaction with angiotensin receptor blockade.

    Science.gov (United States)

    Bishu, Kalkidan; Ogut, Ozgur; Kushwaha, Sudhir; Mohammed, Selma F; Ohtani, Tomohito; Xu, Xiaolei; Brozovich, Frank V; Redfield, Margaret M

    2013-01-01

    While neurohumoral antagonists improve outcomes in heart failure (HF), cardiac remodeling and dysfunction progress and outcomes remain poor. Therapies superior or additive to standard HF therapy are needed. Pharmacologic mTOR inhibition by rapamycin attenuated adverse cardiac remodeling and dysfunction in experimental heart failure (HF). However, these studies used rapamycin doses that produced blood drug levels targeted for primary immunosuppression in human transplantation and therefore the immunosuppressive effects may limit clinical translation. Further, the relative or incremental effect of rapamycin combined with standard HF therapies targeting upstream regulators of cardiac remodeling (neurohumoral antagonists) has not been defined. Our objectives were to determine if anti-remodeling effects of rapamycin were preserved at lower doses and whether rapamycin effects were similar or additive to a standard HF therapy (angiotensin receptor blocker (losartan)). Experimental murine HF was produced by transverse aortic constriction (TAC). At three weeks post-TAC, male mice with established HF were treated with placebo, rapamycin at a dose producing immunosuppressive drug levels (target dose), low dose (50% target dose) rapamycin, losartan or rapamycin + losartan for six weeks. Cardiac structure and function (echocardiography, catheterization, pathology, hypertrophic and fibrotic gene expression profiles) were assessed. Downstream mTOR signaling pathways regulating protein synthesis (S6K1 and S6) and autophagy (LC3B-II) were characterized. TAC-HF mice displayed eccentric hypertrophy, systolic dysfunction and pulmonary congestion. These perturbations were attenuated to a similar degree by oral rapamycin doses achieving target (13.3±2.1 ng/dL) or low (6.7±2.5 ng/dL) blood levels. Rapamycin treatment decreased mTOR mediated regulators of protein synthesis and increased mTOR mediated regulators of autophagy. Losartan monotherapy did not attenuate remodeling, whereas

  3. Mitochondria-Targeted Antioxidant Prevents Cardiac Dysfunction Induced by Tafazzin Gene Knockdown in Cardiac Myocytes

    Directory of Open Access Journals (Sweden)

    Quan He

    2014-01-01

    Full Text Available Tafazzin, a mitochondrial acyltransferase, plays an important role in cardiolipin side chain remodeling. Previous studies have shown that dysfunction of tafazzin reduces cardiolipin content, impairs mitochondrial function, and causes dilated cardiomyopathy in Barth syndrome. Reactive oxygen species (ROS have been implicated in the development of cardiomyopathy and are also the obligated byproducts of mitochondria. We hypothesized that tafazzin knockdown increases ROS production from mitochondria, and a mitochondria-targeted antioxidant prevents tafazzin knockdown induced mitochondrial and cardiac dysfunction. We employed cardiac myocytes transduced with an adenovirus containing tafazzin shRNA as a model to investigate the effects of the mitochondrial antioxidant, mito-Tempo. Knocking down tafazzin decreased steady state levels of cardiolipin and increased mitochondrial ROS. Treatment of cardiac myocytes with mito-Tempo normalized tafazzin knockdown enhanced mitochondrial ROS production and cellular ATP decline. Mito-Tempo also significantly abrogated tafazzin knockdown induced cardiac hypertrophy, contractile dysfunction, and cell death. We conclude that mitochondria-targeted antioxidant prevents cardiac dysfunction induced by tafazzin gene knockdown in cardiac myocytes and suggest mito-Tempo as a potential therapeutic for Barth syndrome and other dilated cardiomyopathies resulting from mitochondrial oxidative stress.

  4. Pre-transplantation specification of stem cells to cardiac lineage for regeneration of cardiac tissue.

    Science.gov (United States)

    Mayorga, Maritza; Finan, Amanda; Penn, Marc

    2009-03-01

    Myocardial infarction (MI) is a lead cause of mortality in the Western world. Treatment of acute MI is focused on restoration of antegrade flow which inhibits further tissue loss, but does not restore function to damaged tissue. Chronic therapy for injured myocardial tissue involves medical therapy that attempts to minimize pathologic remodeling of the heart. End stage therapy for chronic heart failure (CHF) involves inotropic therapy to increase surviving cardiac myocyte function or mechanical augmentation of cardiac performance. Not until the point of heart transplantation, a limited resource at best, does therapy focus on the fundamental problem of needing to replace injured tissue with new contractile tissue. In this setting, the potential for stem cell therapy has garnered significant interest for its potential to regenerate or create new contractile cardiac tissue. While to date adult stem cell therapy in clinical trials has suggested potential benefit, there is waning belief that the approaches used to date lead to regeneration of cardiac tissue. As the literature has better defined the pathways involved in cardiac differentiation, preclinical studies have suggested that stem cell pretreatment to direct stem cell differentiation prior to stem cell transplantation may be a more efficacious strategy for inducing cardiac regeneration. Here we review the available literature on pre-transplantation conditioning of stem cells in an attempt to better understand stem cell behavior and their readiness in cell-based therapy for myocardial regeneration.

  5. Remodeling, Renovation, & Conversion of Educational Facilities.

    Science.gov (United States)

    Association of Physical Plant Administrators of Universities and Colleges, Washington, DC.

    Based on a series of workshops, this collection of papers provides a framework for thought--emphasizing planning within time, flexibility, and maintenance constraints--as well as a practical guide for actual engineering of remodeling/renovation/conversion projects. Is remodeling always less expensive than new construction? Should high initial…

  6. Chromatin Remodelers: From Function to Dysfunction

    Directory of Open Access Journals (Sweden)

    Gernot Längst

    2015-06-01

    Full Text Available Chromatin remodelers are key players in the regulation of chromatin accessibility and nucleosome positioning on the eukaryotic DNA, thereby essential for all DNA dependent biological processes. Thus, it is not surprising that upon of deregulation of those molecular machines healthy cells can turn into cancerous cells. Even though the remodeling enzymes are very abundant and a multitude of different enzymes and chromatin remodeling complexes exist in the cell, the particular remodeling complex with its specific nucleosome positioning features must be at the right place at the right time in order to ensure the proper regulation of the DNA dependent processes. To achieve this, chromatin remodeling complexes harbor protein domains that specifically read chromatin targeting signals, such as histone modifications, DNA sequence/structure, non-coding RNAs, histone variants or DNA bound interacting proteins. Recent studies reveal the interaction between non-coding RNAs and chromatin remodeling complexes showing importance of RNA in remodeling enzyme targeting, scaffolding and regulation. In this review, we summarize current understanding of chromatin remodeling enzyme targeting to chromatin and their role in cancer development.

  7. The dynamic nature of hypertrophic and fibrotic remodelling in the fish ventricle.

    Directory of Open Access Journals (Sweden)

    Adam Nicholas Keen

    2016-01-01

    Full Text Available Chronic pressure or volume overload can cause the vertebrate heart to remodel. The hearts of fish remodel in response to seasonal temperature change. Here we focus on the passive properties of the fish heart. Building upon our previous work on thermal-remodelling of the rainbow trout ventricle, we hypothesized that chronic cooling would initiate a fibrotic cardiac remodelling, with increased myocardial stiffness, similar to that seen with pathological hypertrophy in mammals. We hypothesized that, in contrast to pathological hypertrophy in mammals, the remodelling response in fish would be plastic and the opposite response would occur following chronic warming. Rainbow trout held at 10 °C (control group were chronically (> 8 weeks exposed to cooling (5 °C or warming (18 °C. Chronic cold induced hypertrophy in the highly trabeculated inner layer of the fish heart, with a 41 % increase in myocyte bundle cross-sectional area, and an up-regulation of hypertrophic markers. Cold acclimation also increased collagen deposition by 1.7-fold and caused an up-regulation of collagen promoting genes. In contrast, chronic warming reduced myocyte bundle cross-sectional area, expression of hypertrophic markers and collagen deposition. Functionally, the cold-induced fibrosis and hypertrophy were associated with increased passive stiffness of the whole ventricle and with increased micromechanical stiffness of tissue sections. The opposite occurred with chronic warming. These findings suggest chronic cooling in the trout heart invokes a hypertrophic phenotype with increased cardiac stiffness and fibrosis that are associated with pathological hypertrophy in the mammalian heart. The loss of collagen and increased compliance following warming is particularly interesting as it suggests fibrosis may oscillate seasonally in the fish heart, revealing a more dynamic nature than the fibrosis associated with dysfunction in mammals.

  8. Computational approaches to understand cardiac electrophysiology and arrhythmias

    Science.gov (United States)

    Roberts, Byron N.; Yang, Pei-Chi; Behrens, Steven B.; Moreno, Jonathan D.

    2012-01-01

    Cardiac rhythms arise from electrical activity generated by precisely timed opening and closing of ion channels in individual cardiac myocytes. These impulses spread throughout the cardiac muscle to manifest as electrical waves in the whole heart. Regularity of electrical waves is critically important since they signal the heart muscle to contract, driving the primary function of the heart to act as a pump and deliver blood to the brain and vital organs. When electrical activity goes awry during a cardiac arrhythmia, the pump does not function, the brain does not receive oxygenated blood, and death ensues. For more than 50 years, mathematically based models of cardiac electrical activity have been used to improve understanding of basic mechanisms of normal and abnormal cardiac electrical function. Computer-based modeling approaches to understand cardiac activity are uniquely helpful because they allow for distillation of complex emergent behaviors into the key contributing components underlying them. Here we review the latest advances and novel concepts in the field as they relate to understanding the complex interplay between electrical, mechanical, structural, and genetic mechanisms during arrhythmia development at the level of ion channels, cells, and tissues. We also discuss the latest computational approaches to guiding arrhythmia therapy. PMID:22886409

  9. Obesity and carotid artery remodeling

    DEFF Research Database (Denmark)

    Kozakova, M; Palombo, C; Morizzo, C

    2015-01-01

    BACKGROUND/OBJECTIVE: The present study tested the hypothesis that obesity-related changes in carotid intima-media thickness (IMT) might represent not only preclinical atherosclerosis but an adaptive remodeling meant to preserve circumferential wall stress (CWS) in altered hemodynamic conditions...... and CCA LD (266 healthy subjects with wide range of body weight (24-159 kg)); (B) longitudinal associations between CCA LD and 3-year IMT progression rate (ΔIMT; 571 healthy non-obese subjects without increased cardiovascular (CV) risk); (C) the impact of obesity on CCA geometry and CWS (88 obese subjects...... without CV complications and 88 non-obese subjects matched for gender and age). RESULTS: CCA LD was independently associated with SV that was determined by body size. In the longitudinal study, baseline LD was an independent determinant of ΔIMT, and ΔIMT of subjects in the highest LD quartile...

  10. Molecular switches under TGFβ signalling during progression from cardiac hypertrophy to heart failure.

    Science.gov (United States)

    Heger, J; Schulz, R; Euler, G

    2016-01-01

    Cardiac hypertrophy is a mechanism to compensate for increased cardiac work load, that is, after myocardial infarction or upon pressure overload. However, in the long run cardiac hypertrophy is a prevailing risk factor for the development of heart failure. During pathological remodelling processes leading to heart failure, decompensated hypertrophy, death of cardiomyocytes by apoptosis or necroptosis and fibrosis as well as a progressive dysfunction of cardiomyocytes are apparent. Interestingly, the induction of hypertrophy, cell death or fibrosis is mediated by similar signalling pathways. Therefore, tiny changes in the signalling cascade are able to switch physiological cardiac remodelling to the development of heart failure. In the present review, we will describe examples of these molecular switches that change compensated hypertrophy to the development of heart failure and will focus on the importance of the signalling cascades of the TGFβ superfamily in this process. In this context, potential therapeutic targets for pharmacological interventions that could attenuate the progression of heart failure will be discussed.

  11. Improving cardiac myocytes performance by CNTs platforms

    Directory of Open Access Journals (Sweden)

    Valentina eMartinelli

    2013-09-01

    Full Text Available The application of nanotechnology to the cardiovascular system has increasingly caught scientists’ attention as a potentially powerful tool for the development of new generation devices able to interface, repair or boost the performance of cardiac tissue. Carbon nanotubes (CNTs are considered as promising materials for nanomedicine applications in general and have been recently tested towards excitable cell growth. CNTs are cylindrically shaped structures made up of rolled-up graphene sheets, with unique electrical, thermal and mechanical properties, able to effectively conducting electrical current in electrochemical interfaces. CNTs-based scaffolds have been recently found to support the in vitro growth of cardiac cells: in particular, their ability to improve cardiomyocytes proliferation, maturation and electrical behavior are making CNTs extremely attractive for the development and exploitation of interfaces able to impact on cardiac cells physiology and function.

  12. Cardiac MRI in Athletes

    NARCIS (Netherlands)

    Luijkx, T.

    2012-01-01

    Cardiac magnetic resonance imaging (CMR) is often used in athletes to image cardiac anatomy and function and is increasingly requested in the context of screening for pathology that can cause sudden cardiac death (SCD). In this thesis, patterns of cardiac adaptation to sports are investigated with C

  13. Cardiac arrhythmias

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    2010315 Effects on electrical restitution of given esanolol during cardiopulmonary resuscitation in a swine ventricular fibrillation model. WEI Jie(魏捷),et al. Dept Emerg Med,Renmin Hosp,Wuhan Univ,Wuhan 430060.Chin J Emerg Med 2010;19(3):257-263. Objective To

  14. In utero and lactational 2,3,7,8-tetrachlorodibenzo-p-dioxin exposure: Effects on fetal and adult cardiac gene expression and adult cardiac and renal morphology

    Science.gov (United States)

    The mouse heart is a target of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) during fetal development, and microarray analysis demonstrates significant changes in expression of cardiac genes involved in extracellular matrix (ECM) remodeling. We tested the hypothesis that developmental TCDD exposure wo...

  15. Airway remodeling in asthma: what really matters.

    Science.gov (United States)

    Fehrenbach, Heinz; Wagner, Christina; Wegmann, Michael

    2017-03-01

    Airway remodeling is generally quite broadly defined as any change in composition, distribution, thickness, mass or volume and/or number of structural components observed in the airway wall of patients relative to healthy individuals. However, two types of airway remodeling should be distinguished more clearly: (1) physiological airway remodeling, which encompasses structural changes that occur regularly during normal lung development and growth leading to a normal mature airway wall or as an acute and transient response to injury and/or inflammation, which ultimately results in restoration of a normal airway structures; and (2) pathological airway remodeling, which comprises those structural alterations that occur as a result of either disturbed lung development or as a response to chronic injury and/or inflammation leading to persistently altered airway wall structures and function. This review will address a few major aspects: (1) what are reliable quantitative approaches to assess airway remodeling? (2) Are there any indications supporting the notion that airway remodeling can occur as a primary event, i.e., before any inflammatory process was initiated? (3) What is known about airway remodeling being a secondary event to inflammation? And (4), what can we learn from the different animal models ranging from invertebrate to primate models in the study of airway remodeling? Future studies are required addressing particularly pheno-/endotype-specific aspects of airway remodeling using both endotype-specific animal models and "endotyped" human asthmatics. Hopefully, novel in vivo imaging techniques will be further advanced to allow monitoring development, growth and inflammation of the airways already at a very early stage in life.

  16. Galectin-3 blockade inhibits cardiac inflammation and fibrosis in experimental hyperaldosteronism and hypertension.

    Science.gov (United States)

    Martínez-Martínez, Ernesto; Calvier, Laurent; Fernández-Celis, Amaya; Rousseau, Elodie; Jurado-López, Raquel; Rossoni, Luciana V; Jaisser, Frederic; Zannad, Faiez; Rossignol, Patrick; Cachofeiro, Victoria; López-Andrés, Natalia

    2015-10-01

    Hypertensive cardiac remodeling is accompanied by molecular inflammation and fibrosis, 2 mechanisms that finally affect cardiac function. At cardiac level, aldosterone promotes inflammation and fibrosis, although the precise mechanisms are still unclear. Galectin-3 (Gal-3), a β-galactoside-binding lectin, is associated with inflammation and fibrosis in the cardiovascular system. We herein investigated whether Gal-3 inhibition could block aldosterone-induced cardiac inflammation and fibrosis and its potential role in cardiac damage associated with hypertension. Aldosterone-salt-treated rats presented hypertension, cardiac inflammation, and fibrosis that were prevented by the pharmacological inhibition of Gal-3 with modified citrus pectin. Cardiac inflammation and fibrosis presented in spontaneously hypertensive rats were prevented by modified citrus pectin treatment, whereas Gal-3 blockade did not modify blood pressure levels. In the absence of blood pressure modifications, Gal-3 knockout mice were resistant to aldosterone-induced cardiac inflammation. In human cardiac fibroblasts, aldosterone increased Gal-3 expression via its mineralocorticoid receptor. Gal-3 and aldosterone enhanced proinflammatory and profibrotic markers, as well as metalloproteinase activities in human cardiac fibroblasts, effects that were not observed in Gal-3-silenced cells treated with aldosterone. In experimental hyperaldosteronism, the increase in Gal-3 expression was associated with cardiac inflammation and fibrosis, alterations that were prevented by Gal-3 blockade independently of blood pressure levels. These data suggest that Gal-3 could be a new molecular mechanism linking cardiac inflammation and fibrosis in situations with high-aldosterone levels, such as hypertension.

  17. Reverse right ventricular structural and extracellular matrix remodeling by estrogen in severe pulmonary hypertension.

    Science.gov (United States)

    Nadadur, Rangarajan D; Umar, Soban; Wong, Gabriel; Eghbali, Mansour; Iorga, Andrea; Matori, Humann; Partow-Navid, Rod; Eghbali, Mansoureh

    2012-07-01

    Chronic pulmonary hypertension (PH) leads to right-ventricular failure (RVF) characterized by RV remodeling. Ventricular remodeling is emerging as an important process during heart failure and recovery. Remodeling in RVF induced by PH is not fully understood. Recently we discovered that estrogen (E2) therapy can rescue severe preexisting PH. Here, we focused on whether E2 (42.5 μg·kg(-1)·day(-1), 10 days) can reverse adverse RV structural and extracellular matrix (ECM) remodeling induced by PH using monocrotaline (MCT, 60 mg/kg). RV fibrosis was evident in RVF males. Intact females developed less severe RV remodeling compared with males and ovariectomized (OVX) females. Novel ECM-degrading disintegrin-metalloproteinases ADAM15 and ADAM17 transcripts were elevated ∼2-fold in all RVF animals. E2 therapy reversed RV remodeling in all groups. In vitro, E2 directly inhibited ANG II-induced expression of fibrosis markers as well as the metalloproteinases in cultured cardiac fibroblasts. Estrogen receptor-β agonist diarylpropionitrile (DPN) but not estrogen receptor-α agonist 4,4',4″-(4-propyl-[1H]-pyrazole-1,3,5-triyl)trisphenol (PPT) was as effective as E2 in inhibiting expression of these genes. Expression of ECM-interacting cardiac fetal-gene osteopontin (OPN) also increased ∼9-fold in RVF males. Intact females were partially protected from OPN upregulation (∼2-fold) but OVX females were not. E2 reversed OPN upregulation in all groups. Upregulation of OPN was also reversed in vitro by E2. Plasma OPN was elevated in RVF (∼1.5-fold) and decreased to control levels in the E2 group. RVF resulted in elevated Akt phosphorylation, but not ERK, in the RV, and E2 therapy restored Akt phosphorylation. In conclusion, E2 therapy reverses adverse RV remodeling associated with PH by reversing fibrosis and upregulation of novel ECM enzymes ADAM15, ADAM17, and OPN. These effects are likely mediated through estrogen receptor-β.

  18. Maternal uterine vascular remodeling during pregnancy.

    Science.gov (United States)

    Osol, George; Mandala, Maurizio

    2009-02-01

    Sufficient uteroplacental blood flow is essential for normal pregnancy outcome and is accomplished by the coordinated growth and remodeling of the entire uterine circulation, as well as the creation of a new fetal vascular organ: the placenta. The process of remodeling involves a number of cellular processes, including hyperplasia and hypertrophy, rearrangement of existing elements, and changes in extracellular matrix. In this review, we provide information on uterine blood flow increases during pregnancy, the influence of placentation type on the distribution of uterine vascular resistance, consideration of the patterns, nature, and extent of maternal uterine vascular remodeling during pregnancy, and what is known about the underlying cellular mechanisms.

  19. Cholinergic Regulation of Airway Inflammation and Remodelling

    Directory of Open Access Journals (Sweden)

    Saeed Kolahian

    2012-01-01

    Full Text Available Acetylcholine is the predominant parasympathetic neurotransmitter in the airways that regulates bronchoconstriction and mucus secretion. Recent findings suggest that acetylcholine regulates additional functions in the airways, including inflammation and remodelling during inflammatory airway diseases. Moreover, it has become apparent that acetylcholine is synthesized by nonneuronal cells and tissues, including inflammatory cells and structural cells. In this paper, we will discuss the regulatory role of acetylcholine in inflammation and remodelling in which we will focus on the role of the airway smooth muscle cell as a target cell for acetylcholine that modulates inflammation and remodelling during respiratory diseases such as asthma and COPD.

  20. Advances in chromatin remodeling and human disease.

    Science.gov (United States)

    Cho, Kyoung Sang; Elizondo, Leah I; Boerkoel, Cornelius F

    2004-06-01

    Epigenetic factors alter phenotype without changing genotype. A primary molecular mechanism underlying epigenetics is the alteration of chromatin structure by covalent DNA modifications, covalent histone modifications, and nucleosome reorganization. Remodeling of chromatin structure regulates DNA methylation, replication, recombination, and repair as well as gene expression. As these functions would predict, dysfunction of the proteins that remodel chromatin causes an array of multi-system disorders and neoplasias. Insights from these diseases suggest that during embryonic and fetal life, environmental distortions of chromatin remodeling encode a 'molecular memory' that predispose the individual to diseases in adulthood.

  1. Toward microendoscopy-inspired cardiac optogenetics in vivo: technical overview and perspective

    Science.gov (United States)

    Klimas, Aleksandra; Entcheva, Emilia

    2014-08-01

    The ability to perform precise, spatially localized actuation and measurements of electrical activity in the heart is crucial in understanding cardiac electrophysiology and devising new therapeutic solutions for control of cardiac arrhythmias. Current cardiac imaging techniques (i.e. optical mapping) employ voltage- or calcium-sensitive fluorescent dyes to visualize the electrical signal propagation through cardiac syncytium in vitro or in situ with very high-spatiotemporal resolution. The extension of optogenetics into the cardiac field, where cardiac tissue is genetically altered to express light-sensitive ion channels allowing electrical activity to be elicited or suppressed in a precise cell-specific way, has opened the possibility for all-optical interrogation of cardiac electrophysiology. In vivo application of cardiac optogenetics faces multiple challenges and necessitates suitable optical systems employing fiber optics to actuate and sense electrical signals. In this technical perspective, we present a compendium of clinically relevant access routes to different parts of the cardiac electrical conduction system based on currently employed catheter imaging systems and determine the quantitative size constraints for endoscopic cardiac optogenetics. We discuss the relevant technical advancements in microendoscopy, cardiac imaging, and optogenetics and outline the strategies for combining them to create a portable, miniaturized fiber-based system for all-optical interrogation of cardiac electrophysiology in vivo.

  2. Simulations of trabecular remodeling and fatigue: is remodeling helpful or harmful?

    Science.gov (United States)

    van Oers, René F M; van Rietbergen, Bert; Ito, Keita; Huiskes, Rik; Hilbers, Peter A J

    2011-05-01

    Microdamage-targeted resorption is paradoxal, because it entails the removal of bone from a region that was already overloaded. Under continued intense loading, resorption spaces could potentially cause more damage than they remove. To investigate this problem, we incorporated damage algorithms in a computer-simulation model for trabecular remodeling. We simulated damage accumulation and bone remodeling in a trabecular architecture, for two fatigue regimens, a 'moderate' regimen, and an 'intense' regimen with a higher number of loading cycles per day. Both simulations were also performed without bone remodeling to investigate if remodeling removed or exacerbated the damage. We found that remodeling tends to remove damage under the 'moderate' fatigue regimen, but it exacerbates damage under the 'intense' regimen. This harmful effect of remodeling may play a role in the development of stress fractures.

  3. 78 FR 1162 - Cardiovascular Devices; Reclassification of External Cardiac Compressor

    Science.gov (United States)

    2013-01-08

    ... improper energy transmission by the device. Cardiac arrhythmias or electrical shock. Excessive electrical... and continuous therapy; or prolonged CPR--to avoid/replace rescuer fatigue) and CPR Aid devices should... that incorporate electrical components, appropriate analysis and testing must validate...

  4. Cholinergic regulation of airway inflammation and remodelling

    NARCIS (Netherlands)

    Kolahian, Saeed; Gosens, Reinoud

    2012-01-01

    Acetylcholine is the predominant parasympathetic neurotransmitter in the airways that regulates bronchoconstriction and mucus secretion. Recent findings suggest that acetylcholine regulates additional functions in the airways, including inflammation and remodelling during inflammatory airway disease

  5. Transcriptional networks and chromatin remodeling controlling adipogenesis

    DEFF Research Database (Denmark)

    Siersbæk, Rasmus; Nielsen, Ronni; Mandrup, Susanne

    2012-01-01

    remodeling have revealed 'snapshots' of this cascade and the chromatin landscape at specific time-points of differentiation. These studies demonstrate that multiple adipogenic transcription factors co-occupy hotspots characterized by an open chromatin structure and specific epigenetic modifications...

  6. In utero and lactational 2,3,7,8-tetrachlorodibenzo-p-dioxin exposure: effects on fetal and adult cardiac gene expression and adult cardiac and renal morphology.

    Science.gov (United States)

    Aragon, Andrea C; Kopf, Phillip G; Campen, Matthew J; Huwe, Janice K; Walker, Mary K

    2008-02-01

    The mouse heart is a target of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) during fetal development, and microarray analysis demonstrates significant changes in expression of cardiac genes involved in extracellular matrix (ECM) remodeling. We tested the hypothesis that developmental TCDD exposure would disrupt cardiac ECM expression and be associated with changes in cardiac morphology in adulthood. In one study, time-pregnant C57BL/6 mice were dosed with corn oil or 1.5, 3.0, or 6.0 microg TCDD/kg on gestation day (GD) 14.5 and sacrificed on GD 17.5, when changes in fetal cardiac mRNA expression were analyzed using quantitative PCR. TCDD induced mRNA expression of genes associated with ECM remodeling (matrix metalloproteinase 9 and 13, preproendothelin-1 [preproET-1]), cardiac hypertrophy (atrial natriuretic peptide, beta-myosin heavy chain, osteopontin), and aryl hydrocarbon receptor (AHR) activation (cytochrome P4501A1, AHR repressor). Further, all TCDD-induced changes required the AHR since gene expression was not altered in AHR knockout fetuses. In a second study, time-pregnant mice were treated with corn oil or 6.0 microg TCDD/kg on GD 14.5, and male offspring were assessed for changes in cardiac gene expression and cardiac and renal morphology at 3 months. All TCDD-induced changes in cardiac gene expression observed fetally, except for preproET-1, remained induced in the hearts of adult male offspring. Adult male offspring of TCDD-exposed dams also displayed cardiac hypertrophy, decreased plasma volume, and mild hydronephrosis. These results demonstrate that in utero and lactational TCDD exposures alter cardiac gene expression and cardiac and renal morphology in adulthood, which may increase the susceptibility to cardiovascular dysfunction.

  7. Chromatin Modification and Remodeling in Heart Development

    Directory of Open Access Journals (Sweden)

    Paul Delgado-Olguín

    2006-01-01

    Full Text Available In organogenesis, cell types are specified from determined precursors as morphogenetic patterning takes place. These events are largely controlled by tissue-specific transcription factors. These transcription factors must function within the context of chromatin to activate or repress target genes. Recent evidence suggests that chromatin-remodeling and -modifying factors may have tissue-specific function. Here we review the potential roles for chromatin-remodeling and -modifying proteins in the development of the mammalian heart.

  8. The Chd Family of Chromatin Remodelers

    OpenAIRE

    Marfella, Concetta G.A.; Imbalzano, Anthony N.

    2007-01-01

    Chromatin remodeling enzymes contribute to the dynamic changes that occur in chromatin structure during cellular processes such as transcription, recombination, repair, and replication. Members of the chromodomain helicase DNA-binding (Chd) family of enzymes belong to the SNF2 superfamily of ATP-dependent chromatin remodelers. The Chd proteins are distinguished by the presence of two N-terminal chromodomains that function as interaction surfaces for a variety of chromatin components. Genetic,...

  9. Dynamics of the ethanolamine glycerophospholipid remodeling network.

    Directory of Open Access Journals (Sweden)

    Lu Zhang

    Full Text Available Acyl chain remodeling in lipids is a critical biochemical process that plays a central role in disease. However, remodeling remains poorly understood, despite massive increases in lipidomic data. In this work, we determine the dynamic network of ethanolamine glycerophospholipid (PE remodeling, using data from pulse-chase experiments and a novel bioinformatic network inference approach. The model uses a set of ordinary differential equations based on the assumptions that (1 sn1 and sn2 acyl positions are independently remodeled; (2 remodeling reaction rates are constant over time; and (3 acyl donor concentrations are constant. We use a novel fast and accurate two-step algorithm to automatically infer model parameters and their values. This is the first such method applicable to dynamic phospholipid lipidomic data. Our inference procedure closely fits experimental measurements and shows strong cross-validation across six independent experiments with distinct deuterium-labeled PE precursors, demonstrating the validity of our assumptions. In contrast, fits of randomized data or fits using random model parameters are worse. A key outcome is that we are able to robustly distinguish deacylation and reacylation kinetics of individual acyl chain types at the sn1 and sn2 positions, explaining the established prevalence of saturated and unsaturated chains in the respective positions. The present study thus demonstrates that dynamic acyl chain remodeling processes can be reliably determined from dynamic lipidomic data.

  10. Bone remodeling as a spatial evolutionary game.

    Science.gov (United States)

    Ryser, Marc D; Murgas, Kevin A

    2017-04-07

    Bone remodeling is a complex process involving cell-cell interactions, biochemical signaling and mechanical stimuli. Early models of the biological aspects of remodeling were non-spatial and focused on the local dynamics at a fixed location in the bone. Several spatial extensions of these models have been proposed, but they generally suffer from two limitations: first, they are not amenable to analysis and are computationally expensive, and second, they neglect the role played by bone-embedded osteocytes. To address these issues, we developed a novel model of spatial remodeling based on the principles of evolutionary game theory. The analytically tractable framework describes the spatial interactions between zones of bone resorption, bone formation and quiescent bone, and explicitly accounts for regulation of remodeling by bone-embedded, mechanotransducing osteocytes. Using tools from the theory of interacting particle systems we systematically classified the different dynamic regimes of the spatial model and identified regions of parameter space that allow for global coexistence of resorption, formation and quiescence, as observed in physiological remodeling. In coexistence scenarios, three-dimensional simulations revealed the emergence of sponge-like bone clusters. Comparison between spatial and non-spatial dynamics revealed substantial differences and suggested a stabilizing role of space. Our findings emphasize the importance of accounting for spatial structure and bone-embedded osteocytes when modeling the process of bone remodeling. Thanks to the lattice-based framework, the proposed model can easily be coupled to a mechanical model of bone loading.

  11. Leptin as a mediator between obesity and cardiac dysfunction

    Directory of Open Access Journals (Sweden)

    Joanna Karbowska

    2012-05-01

    Full Text Available  Obesity is now recognised as one of the most important risk factors for heart disease. Obese individuals have high circulating levels of leptin, a hormone secreted by adipose tissue and in­volved in energy homeostasis. Growing evidence suggests that leptin may contribute to the development of cardiac dysfunction. In a large prospective study leptin has been shown to be an independent risk factor for coronary heart disease. An independent positive association has also been found between plasma leptin levels and heart rate in hypertensive patients and heart transplant recipients. In animal studies chronic leptin infusion increased heart rate and blood pressure. It has also been demonstrated that circulating leptin levels are elevated in patients with heart failure. The level of plasma leptin was associated with increased myocardial wall thickness and correlated with left ventricular mass, suggesting a role for this hormone in mediating left ventricular hypertrophy in humans. Moreover, leptin directly induced hypertrophy and hyperplasia in human and rodent cardiomyocytes, accompanied by cardiac extracellular matrix remodelling. Leptin may also influence energy substrate utilisation in cardiac tissue.These findings suggest that leptin acting directly or through the sympathetic nervous system may have adverse effects on cardiac structure and function, and that chronic hyperleptinaemia may greatly increase the risk of cardiac disorders. Additional studies are needed to define the role of leptin in cardiac physiology and pathophysiology, nevertheless the reduction in plasma leptin levels with caloric restriction and weight loss may prevent cardiac dysfunction in obese patients.

  12. Mechanical modulation of cardiac microtubules.

    Science.gov (United States)

    White, Ed

    2011-07-01

    Microtubules are a major component of the cardiac myocyte cytoskeleton. Interventions that alter it may influence cardiac mechanical and electrical activity by disrupting the trafficking of proteins to and from the surface membrane by molecular motors such as dynein, which use microtubules as tracks to step along. Free tubulin dimers may transfer GTP to the α-subunits of G-proteins, thus an increase in free tubulin could increase the activity of G-proteins; evidence for and against such a role exists. There is more general agreement that microtubules act as compression-resisting structures within myocytes, influencing visco-elasticity of myocytes and increasing resistance to shortening when proliferated and resisting deformation from longitudinal shear stress. In response to pressure overload, there can be post-translational modifications resulting in more stable microtubules and an increase in microtubule density. This is accompanied by contractile dysfunction of myocytes which can be reversed by microtubule disruption. There are reports of mechanically induced changes in electrical activity that are dependent upon microtubules, but at present, a consensus is lacking on whether disruption or proliferation would be beneficial in the prevention of arrhythmias. Microtubules certainly play a role in the response of cardiac myocytes to mechanical stimulation, the exact nature and significance of this role is still to be fully determined.

  13. Sudden cardiac death risk stratification.

    Science.gov (United States)

    Deyell, Marc W; Krahn, Andrew D; Goldberger, Jeffrey J

    2015-06-01

    Arrhythmic sudden cardiac death (SCD) may be caused by ventricular tachycardia/fibrillation or pulseless electric activity/asystole. Effective risk stratification to identify patients at risk of arrhythmic SCD is essential for targeting our healthcare and research resources to tackle this important public health issue. Although our understanding of SCD because of pulseless electric activity/asystole is growing, the overwhelming majority of research in risk stratification has focused on SCD-ventricular tachycardia/ventricular fibrillation. This review focuses on existing and novel risk stratification tools for SCD-ventricular tachycardia/ventricular fibrillation. For patients with left ventricular dysfunction or myocardial infarction, advances in imaging, measures of cardiac autonomic function, and measures of repolarization have shown considerable promise in refining risk. Yet the majority of SCD-ventricular tachycardia/ventricular fibrillation occurs in patients without known cardiac disease. Biomarkers and novel imaging techniques may provide further risk stratification in the general population beyond traditional risk stratification for coronary artery disease alone. Despite these advances, significant challenges in risk stratification remain that must be overcome before a meaningful impact on SCD can be realized.

  14. In silico screening of the key cellular remodeling targets in chronic atrial fibrillation.

    Directory of Open Access Journals (Sweden)

    Jussi T Koivumäki

    2014-05-01

    Full Text Available Chronic atrial fibrillation (AF is a complex disease with underlying changes in electrophysiology, calcium signaling and the structure of atrial myocytes. How these individual remodeling targets and their emergent interactions contribute to cell physiology in chronic AF is not well understood. To approach this problem, we performed in silico experiments in a computational model of the human atrial myocyte. The remodeled function of cellular components was based on a broad literature review of in vitro findings in chronic AF, and these were integrated into the model to define a cohort of virtual cells. Simulation results indicate that while the altered function of calcium and potassium ion channels alone causes a pronounced decrease in action potential duration, remodeling of intracellular calcium handling also has a substantial impact on the chronic AF phenotype. We additionally found that the reduction in amplitude of the calcium transient in chronic AF as compared to normal sinus rhythm is primarily due to the remodeling of calcium channel function, calcium handling and cellular geometry. Finally, we found that decreased electrical resistance of the membrane together with remodeled calcium handling synergistically decreased cellular excitability and the subsequent inducibility of repolarization abnormalities in the human atrial myocyte in chronic AF. We conclude that the presented results highlight the complexity of both intrinsic cellular interactions and emergent properties of human atrial myocytes in chronic AF. Therefore, reversing remodeling for a single remodeled component does little to restore the normal sinus rhythm phenotype. These findings may have important implications for developing novel therapeutic approaches for chronic AF.

  15. Effects of Tribuli Saponins on Left Ventricular Remodeling after Acute Myocardial Infarction in Rats with Hyperlipidemia

    Institute of Scientific and Technical Information of China (English)

    GUO Yan; YIN Hui-jun; SHI Da-zhuo; CHEN Ke-ji

    2005-01-01

    Objective: To observe the effect of Tribuli saponins (TS) on left ventricularremodeling after acute myocardial infarction(AMI) in rats with hyperlipemia. Methods: A composite model of myocardial infarction and hyperlipemia was established and treated with TS to observe its effect on cardiac structure and function by echocardiography. Results: (1) Cardiac function: As compared with the model group, the fractional shortening (FS) and ejection fraction (EF) got increased, and the left ventricular end diastolic volume (LVEDV) and systolic volume (LVESV) got lower in the groups treated with high dose TS and simvastatin ( P<0.05 or P<0.01 ), but difference between the two treated groups was insignificant. (2) Cardiac structure: As compared with the model group, the left ventricular dimension end diastole (LVDd) and systole (LVDs) in the groups treated with high dose TS and simvastatin got lower ( P<0.05 or P<0.01 ). No treatment showed any effect on the thickness of ventricular wall. (3)Ventricular weight index: Both high dose TS and simvastatin could decrease the left ventricular weight index (LVWI) ( P<0.05). Conclusion: TS could attenuate the left ventricular remodeling after acute myocardial infarction to certain extent, and improve cardiac function in the early phase after AMI, thus playing an important role in controlling morbidity and mortality of cardiac events and long-term prognosis.

  16. Impact of ejection fraction on the clinical response to cardiac resynchronization therapy in mild heart failure

    DEFF Research Database (Denmark)

    Linde, Cecilia; Daubert, Claude; Abraham, William T;

    2013-01-01

    Current guidelines recommend cardiac resynchronization therapy (CRT) in mild heart failure (HF) patients with QRS prolongation and ejection fraction (EF) ≤30%. To assess the effect of CRT in less severe systolic dysfunction, outcomes in the REsynchronization reVErses Remodeling in Systolic left v...

  17. Cardiac ryanodine receptor gene (hRyR2) mutation underlying catecholaminergic polymorphic ventricular tachycardia in a Chinese adolescent presenting with sudden cardiac arrest and cardiac syncope

    Institute of Scientific and Technical Information of China (English)

    Ngai-Shing Mok; Ching-Wan Lam; Nai-Chung Fong; Yim-Wo Hui; Yuen-Choi Choi; Kwok-Yin Chan

    2006-01-01

    @@ Sudden cardiac death (SCD) in children and adolescents is uncommon and yet it is devastating for both victim's family and the society.Recently, it was increasingly recognized that SCD in young patients with structurally normal heart may be caused by inheritable primary electrical diseases due to the malfunction of cardiac ion channels, a disease entity known as the ion channelopathies.Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a specific form of ion channelopathy which can cause cardiac syncope or SCD in young patients by producing catecholamine-induced bi-directional ventricular tachycardia (BiVT), polymorphic VT and ventricular fibrillation (VF) during physical exertion or emotion.1-7 We reported here an index case of CPVT caused by cardiac ryanodine receptor gene (hRyR2)mutation which presented as cardiac syncope and sudden cardiac arrest in a Chinese adolescent female.

  18. Effect of Shenxinning decoction on ventricular remodeling in AT1 receptor-knockout mice with chronic renal insufficiency

    Directory of Open Access Journals (Sweden)

    Xuejun Yang

    2014-01-01

    Full Text Available Objective: To observe the efficacy of Shenxinning Decoction (SXND in ventricular remodeling in AT1 receptor-knockout (AT1-KO mice with chronic renal insufficiency (CRI. Materials and Methods: AT1-KO mice modeled with subtotal (5/6 nephrectomy were intervened with SXND for 12 weeks. Subsequently, blood urea nitrogen (BUN, serum creatinine (SCr, brain natriuretic peptide (BNP, echocardiography (left ventricular end-diastolic diameter, LVDD; left ventricular end-systolic diameter, LVDS; fractional shortening, FS; and ejection fraction, EF, collagen types I and III in the heart and kidney, myocardial mitochondria, and cardiac transforming growth factor-β1 (TGF-β1 of the AT1-KO mice were compared with the same model with nephrectomy only and untreated with SXND. Results: AT1-KO mice did not affect the process of CRI but it could significantly affect cardiac remodeling process. SXND decreased to some extent the AT1-KO mice′s BUN, SCr, BNP, and cardiac LVDD, LVDS, and BNP, improved FS and EF, lowered the expression of collagen type I and III in heart and kidney, increased the quantity of mitochondria and ameliorated their structure, and down-regulated the expression of TGF-β1. Conclusion: SXND may antagonize the renin-angiotensin system (RAS and decrease uremia toxins, thereby ameliorating ventricular remodeling in CRI. Furthermore, SXND has a mechanism correlated with the improvement of myocardial energy metabolism and the down-regulation of TGF-β1.

  19. 体表脉冲电刺激对昆明小鼠心电活动的影响%Effect of surface electric-impulse stimulation on cardiac electrical activity of Kunming mice

    Institute of Scientific and Technical Information of China (English)

    李永林; 张辉; 史若飞; 汤小曼; 解力; 黄吕; 张晓刚

    2014-01-01

    BACKGROUND: Electrical stimulation at different intensity, frequency and time on the human body may produce a variety of pathophysiological reactions. OBJECTIVE: To observe the effects of surface electric-impulse stimulation on heart rhythm and heart rate in mice. METHODS: Thirty Kunming mice were randomly divided into three groups, each group contained 10 mice. Electrical stimulation at different voltage, time and frequency was respectively applied to the three groups. The stimulus power was supplied by BL-420F Data Acquisition & Analysis System. The II lead electrocardiogram was recorded. The systemic reactions and local body changes of mice were observed.%背景:使用不同强度、频率及时间的电刺激作用于人体,可能产生各种不同的病理生理反应。  目的:观察体表脉冲电刺激对小鼠心律及心率的影响。  方法:将30只昆明小鼠随机分为3组,每组10只,用BL-420F型生物机能实验系统提供刺激电源,对3组昆明小鼠分别予以不同电压、不同时间、不同频率的体表电刺激,然后观察Ⅱ导联心电图、小鼠得全身反应与局部变化。  结果与结论:≤10 V的电刺激对小鼠心率无明显影响,并且未出现心律失常;电压≥15 V时,电刺激可使小鼠心率减慢,停止30 min后心率恢复正常;电压≥35 V时,小鼠出现心率减慢和心律失常,并且停止刺激后心率不能恢复正常;电压>75 V后,小鼠出现室颤。电压为10 V时,脉冲电刺激时间和频率变化对小鼠心电活动影响不显著。说明脉冲电刺激对小鼠心电活动的影响主要由所用电压高低不同引起,电压≤10 V 时对小鼠心电活动无影响;脉冲电刺激时间与电场频率对小鼠心电活动影响不明显。

  20. Cardiac-specific knockout of ETA receptor mitigates low ambient temperature-induced cardiac hypertrophy and contractile dysfunction

    Institute of Scientific and Technical Information of China (English)

    Yingmei Zhang; Linlin Li; Yinan Hua; Jennifer M. Nunn; Feng Dong; Masashi Yanagisawa; Jun Ren

    2012-01-01

    Cold exposure is associated with oxidative stress and cardiac dysfunction.The endothelin (ET) system,which plays a key role in myocardial homeostasis,may participate in cold exposure-induced cardiovascular dysfunction.This study was designed to examine the role of ET-1 in cold stress-induced cardiac geometric and contractile responses.Wild-type (WT) and ETA receptor knockout (ETAKO) mice were assigned to normal or cold exposure (4℃) environment for 2 and 5 weeks prior to evaluation of cardiac geometry,contractile,and intracellular Ca2+ properties.Levels of the temperature sensor transient receptor potential vanlllold (TRPV1),mitochondrlal proteins for biogenesis and oxidative phosphorylatlon,Including UCP2,HSP90,and PGC1α were evaluated.Cold stress triggered cardiac hypertrophy,depressed myocardial contractile capacity,including fractional shortening,peak shortening,and maximal velocity of shortening/relengthening,reduced intracellular Ca2+ release,prolonged intracellular Ca2+ decay and relengthening duration,generation of ROS and superoxide,as well as apoptosls,the effects of which were blunted by ETAKO.Western blotting revealed downregulated TRPV1 and PGC1α as well as upregulated UCP2 and activation of GSK3β,GATA4,and CREB in cold-stressed WT mouse hearts,which were obliterated by ETAKO.Levels of HSP90,an essential regulator for thermotolerance,were unchanged.The TRPV1 agonist SA13353 attenuated whereas TRPV1 antagonist capsazepino mimicked cold stress- or ET-1-induced cardiac anomalies.The GSK3β Inhibitor SB216763 ablated cold stress-induced cardiac contractile (but not remodeling) changes and ET-1-induced TRPV1 downregulation.These data suggest that ETAKO protects against cold exposure-induced cardiac remodeling and dysfunction mediated through TRPV1 and mitochondrlal function.

  1. Myocardial connective tissue growth factor (CCN2/CTGF attenuates left ventricular remodeling after myocardial infarction.

    Directory of Open Access Journals (Sweden)

    Jørgen Gravning

    Full Text Available AIMS: Myocardial CCN2/CTGF is induced in heart failure of various etiologies. However, its role in the pathophysiology of left ventricular (LV remodeling after myocardial infarction (MI remains unresolved. The current study explores the role of CTGF in infarct healing and LV remodeling in an animal model and in patients admitted for acute ST-elevation MI. METHODS AND RESULTS: Transgenic mice with cardiac-restricted overexpression of CTGF (Tg-CTGF and non-transgenic littermate controls (NLC were subjected to permanent ligation of the left anterior descending coronary artery. Despite similar infarct size (area of infarction relative to area at risk 24 hours after ligation of the coronary artery in Tg-CTGF and NLC mice, Tg-CTGF mice disclosed smaller area of scar tissue, smaller increase of cardiac hypertrophy, and less LV dilatation and deterioration of LV function 4 weeks after MI. Tg-CTGF mice also revealed substantially reduced mortality after MI. Remote/peri-infarct tissue of Tg-CTGF mice contained reduced numbers of leucocytes, macrophages, and cells undergoing apoptosis as compared with NLC mice. In a cohort of patients with acute ST-elevation MI (n = 42 admitted to hospital for percutaneous coronary intervention (PCI serum-CTGF levels (s-CTGF were monitored and related to infarct size and LV function assessed by cardiac MRI. Increase in s-CTGF levels after MI was associated with reduced infarct size and improved LV ejection fraction one year after MI, as well as attenuated levels of CRP and GDF-15. CONCLUSION: Increased myocardial CTGF activities after MI are associated with attenuation of LV remodeling and improved LV function mediated by attenuation of inflammatory responses and inhibition of apoptosis.

  2. Cardiac tamponade (image)

    Science.gov (United States)

    Cardiac tamponade is a condition involving compression of the heart caused by blood or fluid accumulation in the space ... they cannot adequately fill or pump blood. Cardiac tamponade is an emergency condition that requires hospitalization.

  3. What Is Cardiac Rehabilitation?

    Science.gov (United States)

    ANSWERS by heart Treatments + Tests What Is Cardiac Rehabilitation? A cardiac rehabilitation (rehab) program takes place in a hospital or ... special help in making lifestyle changes. During your rehabilitation program you’ll… • Have a medical evaluation to ...

  4. [Remodelling of right heart chambers in patients with occupational respiratory diseases in post-contact period].

    Science.gov (United States)

    2011-01-01

    Clinical manifestations of occupational respiratory diseases and functional cardiorespiratory state in workers were studied in thorough examination of 329 workers including main occupations of refractory metals alloys production, who are exposed to polymetallic highly dispersed aerosols in concentrations exceeding the MACs. The data obtained prove changes in intracardial hemodynamics, lower myocardial contractility and lung hypertension even at early stages of the process, progressing in the advanced disease and in post-contact period. Heart remodelling underlies frequent cardiac arrhythmias in occupational respiratory diseases. With that, intensity of the changes reliably increases with higher degree of bronchial obstruction in the patients and could serve as a marker of respiratory failure severity.

  5. Using noise to determine cardiac restitution with memory

    Science.gov (United States)

    Dai, Shu; Keener, James P.

    2012-06-01

    Variation in cardiac pacing cycles, as seen, for example, in heart rate variability, has been observed for decades. Contemporarily, various mathematical models have been constructed to investigate the electrical activity of paced cardiac cells. Yet there has not been a study of these cardiac models when there is variation in the pacing cycles such as noise. We present a method that uses the stochasticity of pacing cycles to determine approximate models of the dynamics of cardiac cells, and use these models to detect bifurcations to alternans.

  6. Reduction in dynamin-2 is implicated in ischaemic cardiac arrhythmias.

    Science.gov (United States)

    Shi, Dan; Xie, Duanyang; Zhang, Hong; Zhao, Hong; Huang, Jian; Li, Changming; Liu, Yi; Lv, Fei; The, Erlinda; Liu, Yuan; Yuan, Tianyou; Wang, Shiyi; Chen, Jinjin; Pan, Lei; Yu, Zuoren; Liang, Dandan; Zhu, Weidong; Zhang, Yuzhen; Li, Li; Peng, Luying; Li, Jun; Chen, Yi-Han

    2014-10-01

    Ischaemic cardiac arrhythmias cause a large proportion of sudden cardiac deaths worldwide. The ischaemic arrhythmogenesis is primarily because of the dysfunction and adverse remodelling of sarcolemma ion channels. However, the potential regulators of sarcolemma ion channel turnover and function in ischaemic cardiac arrhythmias remains unknown. Our previous studies indicate that dynamin-2 (DNM2), a cardiac membrane-remodelling GTPase, modulates ion channels membrane trafficking in the cardiomyocytes. Here, we have found that DNM2 plays an important role in acute ischaemic arrhythmias. In rat ventricular tissues and primary cardiomyocytes subjected to acute ischaemic stress, the DNM2 protein and transcription levels were markedly down-regulated. This DNM2 reduction was coupled with severe ventricular arrhythmias. Moreover, we identified that the down-regulation of DNM2 within cardiomyocytes increases the action potential amplitude and prolongs the re-polarization duration by depressing the retrograde trafficking of Nav1.5 and Kir2.1 channels. These effects are likely to account for the DNM2 defect-induced arrhythmogenic potentials. These results suggest that DNM2, with its multi-ion channel targeting properties, could be a promising target for novel antiarrhythmic therapies.

  7. Cenderitide-eluting film for potential cardiac patch applications.

    Directory of Open Access Journals (Sweden)

    Xu Wen Ng

    Full Text Available Cenderitide, also known as CD-NP, is a designer peptide developed by combining native mammalian c-type natriuretic peptide (CNP and the C-terminus isolated from the dendroapis natriuretic peptide (DNP of the venom from the green mamba. In early studies, intravenous and subcutaneous infusion of cenderitide was reported to reduce left ventricular (LV mass and ameliorate cardiac remodelling. In this work, biodegradable polymeric films encapsulating CD-NP were developed and were investigated for their in vitro release and degradation characteristics. Subsequently, the bioactivity of released peptide and its effects on human cardiac fibroblast (HCF were explored. We achieved sustained release from three films with low, intermediate and high release profiles for 30 days. Moreover, the bioactivity of released peptide was verified from the elevated production of cyclic guanosine monophospate (cGMP. The CD-NP released from films was able to inhibit the proliferation of hypertrophic HCF as well as suppress DNA synthesis in HCF. Furthermore, the sustained delivery from films showed comparable or superior suppressive actions on hypertrophic HCF compared to daily infusion of CD-NP. The results suggest that these films could be used to inhibit fibrosis and reduce cardiac remodelling via local delivery as cardiac patches.

  8. Multiscale Characterization of Impact of Infarct Size on Myocardial Remodeling in an Ovine Infarct Model.

    Science.gov (United States)

    Zhang, Pei; Li, Tielou; Griffith, Bartley P; Wu, Zhongjun J

    2015-01-01

    The surviving myocardium initially compensates the loss of injured myocardium after myocardial infarction (MI) and gradually becomes progressively dysfunctional. There have been limited studies on the effect of infarct size on temporal and spatial alterations in the myocardium during progressive myocardial remodeling. MI with three infarct sizes, i.e. 15, 25 and 35% of the left ventricular (LV) wall, was created in an ovine infarction model. The progressive LV remodeling over a 12-week period was studied. Echocardiography, sonomicrometry, and histological and molecular analyses were carried out to evaluate cardiac function, regional tissue contractile function, structural remodeling and cardiomyocyte hypertrophy, and calcium handling proteins. Twelve weeks after MI, the 15, 25 and 35% MI groups had normalized LV end diastole volumes of 1.4 ± 0.2, 1.7 ± 0.3 and 2.0 ± 0.4 ml/kg, normalized end systole volumes of 1.0 ± 0.1, 1.0 ± 0.2 and 1.3 ± 0.3 ml/kg and LV ejection fractions of 43 ± 3, 42 ± 6 and 34 ± 4%, respectively. They all differed from the sham group (p strain), larger cardiomyocyte size and altered expression of calcium handing proteins in the adjacent myocardium compared to the remote counterpart from the infarct. A significant correlation was found between cardiomyocyte size and remodeling strain in the adjacent zone. A comparative analysis among the three MI groups showed that a larger infarct size (35 vs. 15% MI) was associated with larger remodeling strain, more serious impairment in the cellular structure and composition, and regional contractile function at regional tissue level and LV function at organ level.

  9. Eccentric and concentric cardiac hypertrophy induced by exercise training: microRNAs and molecular determinants

    Directory of Open Access Journals (Sweden)

    T. Fernandes

    2011-09-01

    Full Text Available Among the molecular, biochemical and cellular processes that orchestrate the development of the different phenotypes of cardiac hypertrophy in response to physiological stimuli or pathological insults, the specific contribution of exercise training has recently become appreciated. Physiological cardiac hypertrophy involves complex cardiac remodeling that occurs as an adaptive response to static or dynamic chronic exercise, but the stimuli and molecular mechanisms underlying transduction of the hemodynamic overload into myocardial growth are poorly understood. This review summarizes the physiological stimuli that induce concentric and eccentric physiological hypertrophy, and discusses the molecular mechanisms, sarcomeric organization, and signaling pathway involved, also showing that the cardiac markers of pathological hypertrophy (atrial natriuretic factor, β-myosin heavy chain and α-skeletal actin are not increased. There is no fibrosis and no cardiac dysfunction in eccentric or concentric hypertrophy induced by exercise training. Therefore, the renin-angiotensin system has been implicated as one of the regulatory mechanisms for the control of cardiac function and structure. Here, we show that the angiotensin II type 1 (AT1 receptor is locally activated in pathological and physiological cardiac hypertrophy, although with exercise training it can be stimulated independently of the involvement of angiotensin II. Recently, microRNAs (miRs have been investigated as a possible therapeutic approach since they regulate the translation of the target mRNAs involved in cardiac hypertrophy; however, miRs in relation to physiological hypertrophy have not been extensively investigated. We summarize here profiling studies that have examined miRs in pathological and physiological cardiac hypertrophy. An understanding of physiological cardiac remodeling may provide a strategy to improve ventricular function in cardiac dysfunction.

  10. Eccentric and concentric cardiac hypertrophy induced by exercise training: microRNAs and molecular determinants.

    Science.gov (United States)

    Fernandes, T; Soci, U P R; Oliveira, E M

    2011-09-01

    Among the molecular, biochemical and cellular processes that orchestrate the development of the different phenotypes of cardiac hypertrophy in response to physiological stimuli or pathological insults, the specific contribution of exercise training has recently become appreciated. Physiological cardiac hypertrophy involves complex cardiac remodeling that occurs as an adaptive response to static or dynamic chronic exercise, but the stimuli and molecular mechanisms underlying transduction of the hemodynamic overload into myocardial growth are poorly understood. This review summarizes the physiological stimuli that induce concentric and eccentric physiological hypertrophy, and discusses the molecular mechanisms, sarcomeric organization, and signaling pathway involved, also showing that the cardiac markers of pathological hypertrophy (atrial natriuretic factor, β-myosin heavy chain and α-skeletal actin) are not increased. There is no fibrosis and no cardiac dysfunction in eccentric or concentric hypertrophy induced by exercise training. Therefore, the renin-angiotensin system has been implicated as one of the regulatory mechanisms for the control of cardiac function and structure. Here, we show that the angiotensin II type 1 (AT1) receptor is locally activated in pathological and physiological cardiac hypertrophy, although with exercise training it can be stimulated independently of the involvement of angiotensin II. Recently, microRNAs (miRs) have been investigated as a possible therapeutic approach since they regulate the translation of the target mRNAs involved in cardiac hypertrophy; however, miRs in relation to physiological hypertrophy have not been extensively investigated. We summarize here profiling studies that have examined miRs in pathological and physiological cardiac hypertrophy. An understanding of physiological cardiac remodeling may provide a strategy to improve ventricular function in cardiac dysfunction.

  11. Retinal Remodeling: Concerns, Emerging Remedies, and Future Prospects

    Directory of Open Access Journals (Sweden)

    Vidhyasankar eKrishnamoorthy

    2016-02-01

    Full Text Available Deafferentation results not only in sensory loss, but also in a variety of alterations in the postsynaptic circuitry. These alterations may have detrimental impact on potential treatment strategies. Progressive loss of photoreceptors in retinal degenerative diseases, such as retinitis pigmentosa and age-related macular degeneration, leads to several changes in the remnant retinal circuitry. Müller glial cells undergo hypertrophy and form a glial seal. The second- and third-order retinal neurons undergo morphological, biochemical and physiological alterations. A result of these alterations is that retinal ganglion cells (RGCs, the output neurons of the retina, become hyperactive and exhibit spontaneous, oscillatory bursts of spikes. This aberrant electrical activity degrades the signal-to-noise ratio in RGC responses, and thus the quality of information they transmit to the brain. These changes in the remnant retina, collectively termed retinal remodeling, pose challenges for genetic, cellular and bionic approaches to restore vision. It is therefore crucial to understand the nature of retinal remodeling, how it affects the ability of remnant retina to respond to novel therapeutic strategies, and how to ameliorate its effects. In this article, we discuss these topics, and suggest that the pathological state of the retinal output following photoreceptor loss is reversible, and therefore, amenable to restorative strategies.

  12. Measuring cardiac efficiency using PET/MRI

    Energy Technology Data Exchange (ETDEWEB)

    Gullberg, Grand [Lawrence Berkeley National Laboratory (United States); Aparici, Carina Mari; Brooks, Gabriel [University of California San Francisco (United States); Liu, Jing; Guccione, Julius; Saloner, David; Seo, Adam Youngho; Ordovas, Karen Gomes [Lawrence Berkeley National Laboratory (United States)

    2015-05-18

    Heart failure (HF) is a complex syndrome that is projected by the American Heart Association to cost $160 billion by 2030. In HF, significant metabolic changes and structural remodeling lead to reduced cardiac efficiency. A normal heart is approximately 20-25% efficient measured by the ratio of work to oxygen utilization (1 ml oxygen = 21 joules). The heart requires rapid production of ATP where there is complete turnover of ATP every 10 seconds with 90% of ATP produced by mitochondrial oxidative metabolism requiring substrates of approximately 30% glucose and 65% fatty acids. In our preclinical PET/MRI studies in normal rats, we showed a negative correlation between work and the influx rate constant for 18FDG, confirming that glucose is not the preferred substrate at rest. However, even though fatty acid provides 9 kcal/gram compared to 4 kcal/gram for glucose, in HF the preferred energy source is glucose. PET/MRI offers the potential to study this maladapted mechanism of metabolism by measuring work in a region of myocardial tissue simultaneously with the measure of oxygen utilization, glucose, and fatty acid metabolism and to study cardiac efficiency in the etiology of and therapies for HF. MRI is used to measure strain and a finite element mechanical model using pressure measurements is used to estimate myofiber stress. The integral of strain times stress provides a measure of work which divided by energy utilization, estimated by the production of 11CO2 from intravenous injection of 11C-acetate, provides a measure of cardiac efficiency. Our project involves translating our preclinical research to the clinical application of measuring cardiac efficiency in patients. Using PET/MRI to develop technologies for studying myocardial efficiency in patients, provides an opportunity to relate cardiac work of specific tissue regions to metabolic substrates, and measure the heterogeneity of LV efficiency.

  13. Sudden cardiac death and mitral and aortic valve disease

    Directory of Open Access Journals (Sweden)

    Bockeria O.L.

    2013-09-01

    Independent determinants of sudden death were left ventricular ejection fraction and atrial fibrillation. The main cause of death in patients with mitral valve stenosis is a thromboembolism from the left heart chambers to systemic circulation, and the risk of the latter increases with atrial fibrillation. There is no sudden cardiac death in mitral valve stenosis. The absence of left ventricular remodeling in mitral valve stenosis probably explains this finding. Onset of symptoms and signs of left ventricular dysfunction are the main predictors of sudden death and are indications for surgery. It should be emphasized that the database of sudden cardiac death in patients with valvular heart disease is very limited compared to patients with coronary heart disease and cardiomyopathies. Some issues related to predictors and mechanisms of SCD are currently poorly understood, therefore prevention of sudden cardiac death is difficult, especially in asymptomatic patients.

  14. Pathophysiology of cardiac hypertrophy and heart failure: signaling pathways and novel therapeutic targets.

    Science.gov (United States)

    Tham, Yow Keat; Bernardo, Bianca C; Ooi, Jenny Y Y; Weeks, Kate L; McMullen, Julie R

    2015-09-01

    The onset of heart failure is typically preceded by cardiac hypertrophy, a response of the heart to increased workload, a cardiac insult such as a heart attack or genetic mutation. Cardiac hypertrophy is usually characterized by an increase in cardiomyocyte size and thickening of ventricular walls. Initially, such growth is an adaptive response to maintain cardiac function; however, in settings of sustained stress and as time progresses, these changes become maladaptive and the heart ultimately fails. In this review, we discuss the key features of pathological cardiac hypertrophy and the numerous mediators that have been found to be involved in the pathogenesis of cardiac hypertrophy affecting gene transcription, calcium handling, protein synthesis, metabolism, autophagy, oxidative stress and inflammation. We also discuss new mediators including signaling proteins, microRNAs, long noncoding RNAs and new findings related to the role of calcineurin and calcium-/calmodulin-dependent protein kinases. We also highlight mediators and processes which contribute to the transition from adaptive cardiac remodeling to maladaptive remodeling and heart failure. Treatment strategies for heart failure commonly include diuretics, angiotensin converting enzyme inhibitors, angiotensin II receptor blockers and β-blockers; however, mortality rates remain high. Here, we discuss new therapeutic approaches (e.g., RNA-based therapies, dietary supplementation, small molecules) either entering clinical trials or in preclinical development. Finally, we address the challenges that remain in translating these discoveries to new and approved therapies for heart failure.

  15. 10.2.Cardiac arrhythmias

    Institute of Scientific and Technical Information of China (English)

    1993-01-01

    930257 Electrophysiologic study of reperfu-sion arrhythmias.YIN Hong (尹红),et al.Af-fil Hosp,Shandong Med Univ,Jinan.Chin CirJ 1993;8(1):37—39.Twenty dogs of experimental ischemic reper-fusion were studied with a three-dimensionalmapping system of cardiac electric activity andmultiple—level myocardial recordings by bipolarplunge—needle electrodes.27% of the nonsus-tained ventricular tachycardia (NSVT) of intra-mural reentry occurred in the ischemic subendo-

  16. Cardiac biomarkers in children with congenital heart disease

    Institute of Scientific and Technical Information of China (English)

    Masaya Sugimoto; Seiko Kuwata; Clara Kurishima; Jeong Hye Kim; Yoich Iwamoto; Hideaki Senzaki

    2015-01-01

    Background: Most congenital heart diseases (CHDs) have specific hemodynamics, including volume and pressure overload, as well as cyanosis and pulmonary hypertension, associated with anatomical abnormalities. Such hemodynamic abnormalities can cause activation of neurohormones, inflammatory cytokines, fibroblasts, and vascular endothelial cells, which in turn contribute to the development of pathologic conditions such as cardiac hypertrophy,fi brosis, and cardiac cell damages and death. Measuring biomarker levels facilitates the prediction of these pathological changes, and provides information about the stress placed on the myocardial cells, the severity of the damage, the responses of neurohumoral factors, and the remodeling of the ventricle. Compared to the ample information on cardiac biomarkers in adult heart diseases, data from children with CHD are still limited. Data sources: We reviewed cardiac biomarkers-specifi cally focusing on troponin as a biomarker of myocardial damage, amino-terminal procollagen type III peptide (PIIIP) as a biomarker of myocardialfi brosis and stromal remodeling, and B-type natriuretic peptide (BNP)/N-terminal proBNP as biomarkers of cardiac load and heart failure, by introducing relevant publications, including our own, on pediatric CHD patients as well as adults. Results: Levels of highly sensitive troponin I are elevated in patients with atrial septal defects (ASDs) and ventricular septal defects (VSDs). PIIIP levels are also elevated in patients with ASD, VSD, pulmonary stenosis, and Tetralogy of Fallot. Measurement of BNP and N-terminal proBNP levels shows good correlation with heart failure score in children. Conclusions: In the treatment of children with CHD requiring delicate care, it is vital to know the specifi c degree of myocardial damage and severity of heart failure. Cardiac biomarkers are useful tools for ascertaining the condition of CHDs with ease and are likely to be useful in determining the appropriate care of

  17. 辛伐他汀对大鼠心肌梗死后心室电重构及室颤阈值的影响%Effects of simvastatin on ventricular electrical remodeling and ventricular fibrillation threshold in rats with myocardial infarction

    Institute of Scientific and Technical Information of China (English)

    李帅; 李京波; 朱伟; 余涛; 顾北音; 魏盟

    2011-01-01

    Objective To investigate the effects of simvastatin on ventricular electrical remodeling and ventricular fibrillation threshold after myocardial infarction (MI). Methods MI was induced by ligation of the anterior descending coronary arteries in rats, and the rats survived were randomized to MI group ( n = 8), medium dose simvastatin group ( M-SIM group, n = 8) and high dose simvastatin group ( H-SIM group, n = 8). Another eight rats were served as sham operation controls( sham group). Twenty-four hours after MI, 1 mg· kg - 1· d -1 and 10 mg· kg- 1 · d - 1 simvastatin was dissolved in distilled water and given by gavage to M-SIM group and H-SIM group for 4 weeks, respectively. Isovolume distilled water was given by garage to MI group and Sham group, respectively. Four weeks after MI, echocardiography was conducted, and in vivo electrophysiological examinations were performed. Results There was no significant difference in QTc intervals in each group before MI (P > 0.05). Four weeks after operation, compared with Sham group, QTc intervals was significantly prolonged in MI group ( P < O. 05), effective refractory period (ERP) was shortened in MI group, resulting in downward shifting of ERP-frequency curves (P < 0.05). The incidence of inducible ventricular tachyarrhythmias (IVT) was higher in MI group (P < O. 05), with lower threshold of ventricular fibrillation ( P < 0.05). In M1 group, ERP was significantly prolonged at S1 S1 intervals of 90 ms and 80 ms compared with that at S1 S1 interval of 120 ms ( P < O. 05). QTc intervals in M-SIM group and H-SIM group were significantly shorter than those in MI group (P < 0.05), resulting in upward shifting of ERP-frequency curves, with no significant difference in ERP between S1S1 intervals (P > 0.05). The incidences of IVT in M-SIM group and H-SIM group were also significantly decreased, with significantly higher thresholds of ventricular fibrillation ( P < O. 05). There was no significant difference

  18. Mechanisms of cardiac pain.

    Science.gov (United States)

    Foreman, Robert D; Garrett, Kennon M; Blair, Robert W

    2015-04-01

    Angina pectoris is cardiac pain that typically is manifested as referred pain to the chest and upper left arm. Atypical pain to describe localization of the perception, generally experienced more by women, is referred to the back, neck, and/or jaw. This article summarizes the neurophysiological and pharmacological mechanisms for referred cardiac pain. Spinal cardiac afferent fibers mediate typical anginal pain via pathways from the spinal cord to the thalamus and ultimately cerebral cortex. Spinal neurotransmission involves substance P, glutamate, and transient receptor potential vanilloid-1 (TRPV1) receptors; release of neurokinins such as nuclear factor kappa b (NF-kb) in the spinal cord can modulate neurotransmission. Vagal cardiac afferent fibers likely mediate atypical anginal pain and contribute to cardiac ischemia without accompanying pain via relays through the nucleus of the solitary tract and the C1-C2 spinal segments. The psychological state of an individual can modulate cardiac nociception via pathways involving the amygdala. Descending pathways originating from nucleus raphe magnus and the pons also can modulate cardiac nociception. Sensory input from other visceral organs can mimic cardiac pain due to convergence of this input with cardiac input onto spinothalamic tract neurons. Reduction of converging nociceptive input from the gallbladder and gastrointestinal tract can diminish cardiac pain. Much work remains to be performed to discern the interactions among complex neural pathways that ultimately produce or do not produce the sensations associated with cardiac pain.

  19. The pathogenesis and treatment of cardiac atrophy in cancer cachexia.

    Science.gov (United States)

    Murphy, Kate T

    2016-02-15

    Cancer cachexia is a multifactorial syndrome characterized by a progressive loss of skeletal muscle mass associated with significant functional impairment. In addition to a loss of skeletal muscle mass and function, many patients with cancer cachexia also experience cardiac atrophy, remodeling, and dysfunction, which in the field of cancer cachexia is described as cardiac cachexia. The cardiac alterations may be due to underlying heart disease, the cancer itself, or problems initiated by the cancer treatment and, unfortunately, remains largely underappreciated by clinicians and basic scientists. Despite recent major advances in the treatment of cancer, little progress has been made in the treatment of cardiac cachexia in cancer, and much of this is due to lack of information regarding the mechanisms. This review focuses on the cardiac atrophy associated with cancer cachexia, describing some of the known mechanisms and discussing the current and future therapeutic strategies to treat this condition. Above all else, improved awareness of the condition and an increased focus on identification of mechanisms and therapeutic targets will facilitate the eventual development of an effective treatment for cardiac atrophy in cancer cachexia.

  20. Cardiac conductive system excitation maps using intracardiac tissue Doppler imaging

    Institute of Scientific and Technical Information of China (English)

    尹立雪; 郑昌琼; 蔡力; 郑翊; 李春梅; 邓燕; 罗芸; 李德玉; 赵树魁

    2003-01-01

    Objective To precisely visualize cardiac anatomic structures and simultaneously depict ele ctro-mechanical events for the purpose of precise underblood intervention. Methods Intracardiac high-resolution tissue Doppler imaging was used to map realt imemyocardial contractions in response to electrical activation within the anat omic structure of the cardiac conductive system using a canine open-chest model . Results The detailed inner anatomic structure of the cardiac conductive system at differ entsites (i.e., sino-atrial, atrial wall, atrial-ventricular node and ventr icular wall) with the inside onset and propagation of myocardial velocity and ac celeration induced by electrical activation was clearly visualized and quan titatively evaluated.Conclusion The simultaneous single modality visualization of the anatomy, function and electrical events of the cardiac conductive system will foster target pacing and pre cision ablation.

  1. Permanent ligation of the left anterior descending coronary artery in mice: a model of post-myocardial infarction remodelling and heart failure.

    Science.gov (United States)

    Muthuramu, Ilayaraja; Lox, Marleen; Jacobs, Frank; De Geest, Bart

    2014-12-02

    Heart failure is a syndrome in which the heart fails to pump blood at a rate commensurate with cellular oxygen requirements at rest or during stress. It is characterized by fluid retention, shortness of breath, and fatigue, in particular on exertion. Heart failure is a growing public health problem, the leading cause of hospitalization, and a major cause of mortality. Ischemic heart disease is the main cause of heart failure. Ventricular remodelling refers to changes in structure, size, and shape of the left ventricle. This architectural remodelling of the left ventricle is induced by injury (e.g., myocardial infarction), by pressure overload (e.g., systemic arterial hypertension or aortic stenosis), or by volume overload. Since ventricular remodelling affects wall stress, it has a profound impact on cardiac function and on the development of heart failure. A model of permanent ligation of the left anterior descending coronary artery in mice is used to investigate ventricular remodelling and cardiac function post-myocardial infarction. This model is fundamentally different in terms of objectives and pathophysiological relevance compared to the model of transient ligation of the left anterior descending coronary artery. In this latter model of ischemia/reperfusion injury, the initial extent of the infarct may be modulated by factors that affect myocardial salvage following reperfusion. In contrast, the infarct area at 24 hr after permanent ligation of the left anterior descending coronary artery is fixed. Cardiac function in this model will be affected by 1) the process of infarct expansion, infarct healing, and scar formation; and 2) the concomitant development of left ventricular dilatation, cardiac hypertrophy, and ventricular remodelling. Besides the model of permanent ligation of the left anterior descending coronary artery, the technique of invasive hemodynamic measurements in mice is presented in detail.

  2. MicroRNA-101a Inhibits Cardiac Fibrosis Induced by Hypoxia via Targeting TGFβRI on Cardiac Fibroblasts

    Directory of Open Access Journals (Sweden)

    Xin Zhao

    2015-01-01

    Full Text Available Background/Aims: Hypoxia is a basic pathological challenge that is associated with numerous cardiovascular disorders including aberrant cardiac remodeling. Transforming growth factor beta (TGF-β signaling pathway plays a pivotal role in mediating cardiac fibroblast (CF function and cardiac fibrosis. Recent data suggested that microRNA-101a (miR-101a exerted anti-fibrotic effects in post-infarct cardiac remodeling and improved cardiac function. This study aimed to investigate the potential relationship between hypoxia, miR-101a and TGF-β signaling pathway in CFs. Methods and Results: Two weeks following coronary artery occlusion in rats, the expression levels of both TGFβ1 and TGFβRI were increased, but the expression of miR-101a was decreased at the site of the infarct and along its border. Cultured rat neonatal CFs treated with hypoxia were characterized by the up-regulation of TGFβ1 and TGFβRI and the down-regulation of miR-101a. Delivery of miR-101a mimics significantly suppressed the expression of TGFβRI and p-Smad 3, CF differentiation and collagen content of CFs. These anti-fibrotic effects were abrogated by co-transfection with AMO-miR-101a, an antisense inhibitor of miR-101a. The repression of TGFβRI, a target of miR-101a, was validated by luciferase reporter assays targeting the 3'UTR of TGFβRI. Additionally, we found that overexpression of miR-101a reversed the improved migration ability of CFs and further reduced CF proliferation caused by hypoxia. Conclusion: Our study illustrates that miR-101a exerts anti-fibrotic effects by targeting TGFβRI, suggesting that miR-101a plays a multi-faceted role in modulating TGF-β signaling pathway and cardiac fibrosis.

  3. Echocardiographic assessment for the reverse effect of amlodipine on left ventricular remodeling and cardiac function%超声心动图评价氨氯地平对左室重构及心功能干预作用的研究

    Institute of Scientific and Technical Information of China (English)

    陈慧慧; 王建春; 赵勇; 邵建华

    2012-01-01

    Objective To evaluate the effects of amlodipine on left ventricular hypertrophy (LVH) and cardiac function assessed by echocardiography in patients with essential hypertension. Methods A total number of 120 hypertensive patients with LVH were randomly assigned to two regimens for 6 months: Group A (n=60) were treated with amlodipine. while Group B (n=60) with benazepril. Both groups had not taken any antihypertensive agents (or at least 4~6 weeks. Blood pressures and adverse reaction during treatment were recorded. Echocardiography was applied to assess the morphological and functional changes of heart before and after 6-month treatment. Results Compared with those before treatment, the LVM1 in both groups decreased significantly and the E peak. E/A ratio and LVEF increased significantly after treatment ( P<0. 05). The LVEF in group A increased more notably than that in group B ( P<0. 05). Conclusion Amlodipine can effectively lower blood pressures, reverse LVH and improve cardiac function.%目的 应用超声心动图技术评价氨氯地平对原发性高血压左室肥厚(LVH)及心脏功能的干预作用.方法 将120例原发性高血压LVH患者随机分为A、B两组,A组(n=60)予以氨氯地平治疗,B组(n=60)予以贝那普利治疗.疗程6个月.两组在入选前4~6周末服用降压药物,观察治疗过程中患者血压变化及药物不良反应,并且应用超声心动图测定治疗前后心脏形态及功能指标.结果 与用药前比较,A、B两组患者治疗后左室质量指数均下降,E峰,E/A比值、左室射血分数(LVEF)均升高,A峰均降低(P<0.05);A组患者LVEF的改善程度优于B组( P<0.05).结论 氨氯地平具有较好的降压、逆转左室肥厚并且改善心脏功能的作用.

  4. Cardiac Fibroblast-Specific Activating Transcription Factor 3 Protects Against Heart Failure by Suppressing MAP2K3-p38 Signaling.

    Science.gov (United States)

    Li, Yulin; Li, Zhenya; Zhang, Congcong; Li, Ping; Wu, Yina; Wang, Chunxiao; Lau, Wayne Bond; Ma, Xin-Liang; Du, Jie

    2017-03-01

    Background -Hypertensive ventricular remodeling is a common cause of heart failure. However, the molecular mechanisms regulating ventricular remodeling remain poorly understood. Methods -We used a discovery-driven/nonbiased approach to indentify increased ATF3 expression in hypertensive heart. We employed loss/gain of function approaches to understand the role of ATF3 in heart failure. We also examine the mechanisms through transcriptome, CHIP-seq analysis and in vivo and vitro experiments. Results -ATF3 expression increased in murine hypertensive heart and human hypertrophic heart. Cardiac fibroblast cells are the primary cell type expressing high ATF3 levels in response to hypertensive stimuli. ATF3 knockout (ATF3KO) markedly exaggerated hypertensive ventricular remodeling, a state rescued by lentivirus-mediated/miRNA-aided cardiac fibroblast-selective ATF3 overexpression. Conversely, conditional cardiac fibroblast cell-specific ATF3 transgenic overexpression significantly ameliorated ventricular remodeling and heart failure. We identified Map2K3 as a novel ATF3 target. ATF3 binds with the Map2K3 promoter, recruiting HDAC1, resulting in Map2K3 gene-associated histone deacetylation, thereby inhibiting Map2K3 expression. Genetic Map2K3 knockdown rescued the pro-fibrotic/hypertrophic phenotype in ATF3KO cells. Finally, we demonstrated that p38 is the downstream molecule of Map2K3 mediating the pro-fibrotic/hypertrophic effects in ATF3KO animals. Inhibition of p38 signaling reduced TGF-β signaling-related pro-fibrotic and hypertrophic gene expression, and blocked exaggerated cardiac remodeling in ATF3KO cells. Conclusions -Our study provides the first evidence that ATF3 upregulation in cardiac fibroblasts in response to hypertensive stimuli protects heart by suppressing Map2K3 expression and subsequent p38-TGF-β signaling. These results suggest that positive modulation of cardiac fibroblast ATF3 may represent a novel therapeutic approach against hypertensive

  5. Biomimetic materials design for cardiac tissue regeneration.

    Science.gov (United States)

    Dunn, David A; Hodge, Alexander J; Lipke, Elizabeth A

    2014-01-01

    Cardiovascular disease is the leading cause of death worldwide. In the absence of sufficient numbers of organs for heart transplant, alternate approaches for healing or replacing diseased heart tissue are under investigation. Designing biomimetic materials to support these approaches will be essential to their overall success. Strategies for cardiac tissue engineering include injection of cells, implantation of three-dimensional tissue constructs or patches, injection of acellular materials, and replacement of valves. To replicate physiological function and facilitate engraftment into native tissue, materials used in these approaches should have properties that mimic those of the natural cardiac environment. Multiple aspects of the cardiac microenvironment have been emulated using biomimetic materials including delivery of bioactive factors, presentation of cell-specific adhesion sites, design of surface topography to guide tissue alignment and dictate cell shape, modulation of mechanical stiffness and electrical conductivity, and fabrication of three-dimensional structures to guide tissue formation and function. Biomaterials can be engineered to assist in stem cell expansion and differentiation, to protect cells during injection and facilitate their retention and survival in vivo, and to provide mechanical support and guidance for engineered tissue formation. Numerous studies have investigated the use of biomimetic materials for cardiac regeneration. Biomimetic material design will continue to exploit advances in nanotechnology to better recreate the cellular environment and advance cardiac regeneration. Overall, biomimetic materials are moving the field of cardiac regenerative medicine forward and promise to deliver new therapies in combating heart disease.

  6. Strategies for Energy Efficient Remodeling: SEER 2003 Case Study Report

    Energy Technology Data Exchange (ETDEWEB)

    None

    2004-11-01

    The goal of the Strategies for Energy Efficiency in Remodeling (SEER) project is to provide information, based on research and case studies, to remodelers and consumers about opportunities to increase home energy performance.

  7. Stimulating endogenous cardiac regeneration

    Directory of Open Access Journals (Sweden)

    Amanda eFinan

    2015-09-01

    Full Text Available The healthy adult heart has a low turnover of cardiac myocytes. The renewal capacity, however, is augmented after cardiac injury. Participants in cardiac regeneration include cardiac myocytes themselves, cardiac progenitor cells, and peripheral stem cells, particularly from the bone marrow compartment. Cardiac progenitor cells and bone marrow stem cells are augmented after cardiac injury, migrate to the myocardium, and support regeneration. Depletion studies of these populations have demonstrated their necessary role in cardiac repair. However, the potential of these cells to completely regenerate the heart is limited. Efforts are now being focused on ways to augment these natural pathways to improve cardiac healing, primarily after ischemic injury but in other cardiac pathologies as well. Cell and gene therapy or pharmacological interventions are proposed mechanisms. Cell therapy has demonstrated modest results and has passed into clinical trials. However, the beneficial effects of cell therapy have primarily been their ability to produce paracrine effects on the cardiac tissue and recruit endogenous stem cell populations as opposed to direct cardiac regeneration. Gene therapy efforts have focused on prolonging or reactivating natural signaling pathways. Positive results have been demonstrated to activate the endogenous stem cell populations and are currently being tested in clinical trials. A potential new avenue may be to refine pharmacological treatments that are currently in place in the clinic. Evidence is mounting that drugs such as statins or beta blockers may alter endogenous stem cell activity. Understanding the effects of these drugs on stem cell repair while keeping in mind their primary function may strike a balance in myocardial healing. To maximize endogenous cardiac regeneration,a combination of these approaches couldameliorate the overall repair process to incorporate the participation ofmultiple cell players.

  8. Incomplete RV Remodeling After Transcatheter ASD Closure in Pediatric Age.

    Science.gov (United States)

    Agha, Hala M; El-Saiedi, Sonia A; Shaltout, Mohamed F; Hamza, Hala S; Nassar, Hayat H; Abdel-Aziz, Doaa M; Tantawy, Amira Esmat El

    2015-10-01

    Published data showing the intermediate effect of transcatheter device closure of atrial septal defect (ASD) in the pediatric age-group are scarce. The objective of the study was to assess the effects of transcatheter ASD closure on right and left ventricular functions by tissue Doppler imaging (TDI). The study included 37 consecutive patients diagnosed as ASD secundum by transthoracic echocardiography and TEE and referred for transcatheter closure at Cairo University Specialized Pediatric Hospital, Egypt, from October 2010 to July 2013. Thirty-seven age- and sex-matched controls were selected. TDI was obtained using the pulsed Doppler mode, interrogating the right cardiac border (the tricuspid annulus) and lateral mitral annulus, and myocardial performance index (MPI) was calculated at 1-, 3-, 6- and 12-month post-device closure. Transcatheter closure of ASD and echocardiographic examinations were successfully performed in all patients. There were no significant differences between two groups as regards the age, gender, weight or BSA. TDI showed that patients with ASD had significantly prolonged isovolumetric contraction, relaxation time and MPI compared with control group. Decreased tissue Doppler velocities of RV and LV began at one-month post-closure compared with the controls. Improvement in RVMPI and LVMPI began at 1-month post-closure, but they are still prolonged till 1 year. Reverse remodeling of right and left ventricles began 1 month after transcatheter ASD closure, but did not completely normalize even after 1 year of follow-up by tissue Doppler imaging.

  9. The new electric comfort; Le nouveau confort electrique

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-11-01

    The document proposed by EDF, deals with the Vivrelec offer. This independent organism proposes a technical assistance to the customer in the calculation of an electric heating installation. Examples of cost of electric heating in thermally insulated houses, advices for the remodeling of old houses and a state of the art of the electric heaters are provided. (A.L.B.)

  10. Mechanisms of Airway Remodeling in Asthma

    Directory of Open Access Journals (Sweden)

    Etsuko Tagaya

    2007-01-01

    To date, many studies have identified candidate mechanisms and mediators for these observed structural changes, which are thus potential targets in the treatment of asthma. In this review, we describe the recent knowledge of the mechanisms and clinical implications of airway remodeling in asthma.

  11. Revealing remodeler function: Varied and unique

    Science.gov (United States)

    Eastlund, Allen

    Chromatin remodelers perform a necessary and required function for the successful expression of our genetic code. By modifying, shifting, or ejecting nucleosomes from the chromatin structure they allow access to the underlying DNA to the rest of the cell's machinery. This research has focused on two major remodeler motors from major families of chromatin remodelers: the trimeric motor domain of RSC and the motor domain of the ISWI family, ISWI. Using primarily stopped-flow spectrofluorometry, I have categorized the time-dependent motions of these motor domains along their preferred substrate, double-stranded DNA. Combined with collected ATP utilization data, I present the subsequent analysis and associated conclusions that stem from the underlying assumptions and models. Interestingly, there is little in common between the investigated proteins aside from their favored medium. While RSC exhibits modest translocation characteristics and highly effective motion with the ability for large molecular forces, ISWI is not only structurally different but highly inefficient in its motion leading to difficulties in determining its specific translocation mechanics. While chromatin remodeling is a ubiquitous facet of eukaryotic life, there remains much to be understood about their general mechanisms.

  12. Link between vitamin D and airway remodeling

    Directory of Open Access Journals (Sweden)

    Berraies A

    2014-04-01

    Full Text Available Anissa Berraies, Kamel Hamzaoui, Agnes HamzaouiPediatric Respiratory Diseases Department, Abderrahmen Mami Hospital, Ariana, and Research Unit 12SP15 Tunis El Manar University, Tunis, TunisiaAbstract: In the last decade, many epidemiologic studies have investigated the link between vitamin D deficiency and asthma. Most studies have shown that vitamin D deficiency increases the risk of asthma and allergies. Low levels of vitamin D have been associated with asthma severity and loss of control, together with recurrent exacerbations. Remodeling is an early event in asthma described as a consequence of production of mediators and growth factors by inflammatory and resident bronchial cells. Consequently, lung function is altered, with a decrease in forced expiratory volume in one second and exacerbated airway hyperresponsiveness. Subepithelial fibrosis and airway smooth muscle cell hypertrophy are typical features of structural changes in the airways. In animal models, vitamin D deficiency enhances inflammation and bronchial anomalies. In severe asthma of childhood, major remodeling is observed in patients with low vitamin D levels. Conversely, the antifibrotic and antiproliferative effects of vitamin D in smooth muscle cells have been described in several experiments. In this review, we briefly summarize the current knowledge regarding the relationship between vitamin D and asthma, and focus on its effect on airway remodeling and its potential therapeutic impact for asthma.Keywords: vitamin D, asthma, airway remodeling, airway smooth muscle, supplementation

  13. Retinal remodeling in human retinitis pigmentosa.

    Science.gov (United States)

    Jones, B W; Pfeiffer, R L; Ferrell, W D; Watt, C B; Marmor, M; Marc, R E

    2016-09-01

    Retinitis Pigmentosa (RP) in the human is a progressive, currently irreversible neural degenerative disease usually caused by gene defects that disrupt the function or architecture of the photoreceptors. While RP can initially be a disease of photoreceptors, there is increasing evidence that the inner retina becomes progressively disorganized as the outer retina degenerates. These alterations have been extensively described in animal models, but remodeling in humans has not been as well characterized. This study, using computational molecular phenotyping (CMP) seeks to advance our understanding of the retinal remodeling process in humans. We describe cone mediated preservation of overall topology, retinal reprogramming in the earliest stages of the disease in retinal bipolar cells, and alterations in both small molecule and protein signatures of neurons and glia. Furthermore, while Müller glia appear to be some of the last cells left in the degenerate retina, they are also one of the first cell classes in the neural retina to respond to stress which may reveal mechanisms related to remodeling and cell death in other retinal cell classes. Also fundamentally important is the finding that retinal network topologies are altered. Our results suggest interventions that presume substantial preservation of the neural retina will likely fail in late stages of the disease. Even early intervention offers no guarantee that the interventions will be immune to progressive remodeling. Fundamental work in the biology and mechanisms of disease progression are needed to support vision rescue strategies.

  14. Immune modulation of resistance artery remodelling.

    Science.gov (United States)

    Schiffrin, Ernesto L

    2012-01-01

    Low-grade inflammation plays a role in cardiovascular disease. The innate and the adaptive immune responses participate in mechanisms that contribute to inflammatory responses. It has been increasingly appreciated that different subsets of lymphocytes and the cytokines they produce modulate the vascular remodelling that occurs in cardiovascular disease. Effector T cells such as T-helper (Th) 1 (interferon-γ-producing) and Th2 lymphocytes (that produce interleukin-4), as well as Th17 (that produce interleukin-17), and T suppressor lymphocytes including regulatory T cells (Treg), which express the transcription factor forkhead box P3 (Foxp3), are involved in the remodelling of small arteries that occurs under the action of angiotensin II, deoxycorticosterone-salt and aldosterone-salt, as well as in models of hypertension such as the Dahl-salt-sensitive rat. The mechanism whereby the immune system is activated is unclear, but it has been suggested that neo-antigens may be generated by the elevation of blood pressure or other stimuli, leading to the activation of the immune response. Activated Th1 may contribute to vascular remodelling directly on blood vessels via effects of the cytokines produced or indirectly by actions on the kidney. The protective effect of Treg may be mediated similarly directly or via renal effects. These data offer promise for the discovery of new therapeutic targets to ameliorate vascular remodelling, which could lead to improved outcome in cardiovascular disease in humans.

  15. Direct and reflex cardiac bradydysrhythmias from small vagal nerve stiumaltions.

    Science.gov (United States)

    Hageman, G R; Randall, W C; Armour, J A

    1975-03-01

    Alterations in cardiac pacemaker location, its rate of discharge, and A-V conduction patterns were induced in anesthetized adult dogs by electrical stimulation of the thoracic vagi and their small cardiac branches before and after cervical vagotomy. Electrical activity from small, contiguous bipolar silver electrodes was amplified and recorded by an optical oscillograph. The electrodes were located over the SA node, the three internodal pathways, the left atrium, and ventricular epicardium. A hoffman-type plaque electrode was placed over the A-V node to record a His bundle electrogram simultaneously with a Lead II electrocardiogram. Electrical stimulation of the intact left recurrent laryngeal nerve and its cardiac branches before and after vagotomy induced both direct and reflex effects on SA nodal cycle length. Efferent dromotropic effects on the A-V node varied from first- to third-degree heart block during stimulation of individual left recurrent cardiac branches. Stimulation of the right recurrent cardiac nerve induced atrial bradycardia with heart block above the His bundle. Stimulation of individual right vagal branches near the heart induced bradycardia, cardiac asystole, shifts in atrial pacemaker location, or activation of His pacemakers. Establishment of the His rhythm probably indicates selective inhibition of supraventricular but not of the His bundle. Asystole and His rhythms induced during stimulation of the more caudal branches of the right cardiac vagal nerves were generally reflexly mediated and were abolished by cervical vagotomy.

  16. Clofibrate, calcium and cardiac muscle.

    Science.gov (United States)

    Fairhurst, A S; Wickie, G; Peabody, T

    1982-03-01

    The anti-hyperlipidemic drug clofibrate produces negative inotropic effects and arrythmias in isolated perfused rabbit heart Langendorff preparations. In electrically stimulated rat left atria, clofibrate produces negative inotropic effects, the speed of onset and extent of which are decreased by raising the Ca concentration of the bathing medium. Sensitivity of isolated rat atria to clofibrate is not increased when the tissues are stimulated under slow Ca channel conditions, in which the tissues are activated by either isoproterenol or dibutyryl cyclic AMP, although sensitivity to clofibrate is decreased when atria are exposed to increasing concentrations of norepinephrine. Increasing the stimulation frequency of isolated guinea-pig atria to produce a positive treppe also decreases the inhibitory effect of clofibrate, while in rat atria the typical negative treppe is altered towards a positive treppe in presence of clofibrate. The effects of paired electrical stimulation are not diminished by the drug, suggesting that Ca release from the sarcoplasmic reticulum is not affected by clofibrate, although the drug inhibits the rate of Ca uptake by isolated cardiac sarcoplasmic reticulum and mitochondria. These results suggest that clofibrate has multiple effects on Ca functions in cardiac muscle.

  17. Effect of hepatocyte growth factor on left ventricular remodeling after acute myocardial infarction in canine

    Institute of Scientific and Technical Information of China (English)

    Ping LI; Tingshu YANG; Liling LIANG

    2006-01-01

    Background and objectives To investigate the effect of hepatocyte growth factor (HGF) on left ventricular (LV) remodeling after acute myocardial infarction (AMI). Methods AMI was produced by ligation of proximal left anterior descending coronary artery(LAD) in 12 mongrel canines. These animals were randomized into 2 groups. In HGF group (n=6), canines were injected with pcDNA3-HGF lml (about 300ug) at the margin of infarcted myocardium; in control group (n=6) canines were injected with equal volume of normal saline. Cardiac function and left ventricular remodeling were evaluated with echocardiography at 1, 4, 8 weeks after MI. LV myocardium specimens were obtained at 8 weeks and stained with hematoxylin and eosin for histological examination or with sirius red to assess the collagen content. Results Compared with control group, LVEF in HGF group was significantly higher at 4 weeks (49.61+6.66 vs 39.84+6.39; P<0.05) and at 8 weeks (51.57+8.53 vs 40.61+7.67; P<0.05) after AMI, while LVESV was significantly lower in HGF group than that in control group at 8 weeks after AMI (18.98+3.47 vs 25.66+5.86; P<0.05). Posterior left ventricular wall thickness decreased significantly from 1 wk to 8 wks after AMI in control group, while remained unchanged in HGF group. Compared with control group, histological examination showed more neovascularization and less scar, and sirius red staining indicated higher volume of type Ⅲ collagen (7.10±4.06% vs 3.77±1.09%; P<0.05) and lower collagen Ⅰ/Ⅲ ratio value (1.11±0.52 vs 2.94±2.48; P<0.05)in HGF group. Conclusion HGF gene transfer might improve cardiac function and LV remodeling after acute myocardial infarction by stimulating angiogenesis, reducing fibrosis, and reducing myocardial scarring.

  18. Mechanisms of improvement of left ventricle remodeling by transplanting two kinds of autologous bone marrow stem cells in pigs

    Institute of Scientific and Technical Information of China (English)

    LI Shu-ren; WU Di; DONG Jie; XUN Li-ying; GAO Li-hui; JIN Fu-chang; QI Xiao-yong; HU Fu-li; ZHANG Jian-qing; WANG Tian-hong; DANG Yi; MENG Cun-liang; LIU Hui-liang; LI Ying-xiao

    2008-01-01

    Background The necrosis of a large number of myocardial cells after acute my