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Results 351 - 400 of 928
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Moro Pierre-Julien - - 2011
During ischaemia, the extracellular level of adenosine increases, which has cytotoxic effects. In endothelium, cell surface adenosine deaminase (ADA) complexing CD26 is coordinately induced during ischaemia as part of an adaptative response by eliminating adenosine. We examined whether a similar mechanism exists for mononuclear cells. We studied mononuclear cell surface ...
Wall Samuel T - - 2012
Myocardial infarction (MI) significantly alters the structure and function of the heart. As abnormal strain may drive heart failure and the generation of arrhythmias, we used computational methods to simulate a left ventricle with an MI over the course of a heartbeat to investigate strains and their potential implications to ...
Jochum Thomas - - 2011
BACKGROUND: Alcohol withdrawal syndrome is associated with an increased incidence of cardiac arrhythmias and sudden cardiac death. Heart rate turbulence (HRT) parameters were applied during withdrawal to estimate cardiac regulation during treatment with clomethiazole. METHODS: Twenty-two patients suffering from alcohol withdrawal syndrome were included in the study. Heart rate regulation ...
Sun Lihan - - 2011
Nitroglycerin, which treats impaired cardiac function through vasodilation as it is converted to nitric oxide, is used worldwide for patients with various ischemic and congestive cardiac diseases, including angina pectoris. Nevertheless, after continuous treatment, the benefits of nitroglycerin are limited by the development of tolerance to the drug. Nitroglycerin tolerance ...
Tverskaya M S - - 2011
Contractile cardiomyocyte metabolism was studied by histochemical methods in experimental stenosis of the aorta complicated and not by heart failure. Acceleration of the citric acid cycle, more intense oxidation of free fatty acids and their metabolites, glycolysis intensification, and higher activity of shuttle mechanisms were found in the contractile cardiomyocytes ...
Schrier Robert W - - 2011
Sodium and water retention in cardiac failure and cirrhosis is pivotal in the morbidity and mortality of patients with these disorders. Moreover, the pathophysiology of these edematous disorders is quite similar. Both disorders have activation of the renin-angiotensin-aldosterone system, increased sympathetic activity, and nonosmotic stimulation of arginine vasopressin, which is ...
Oostendorp T F - - 2011
Determining electrical activation of the heart in a noninvasive way is one of the challenges in cardiac electrophysiology. The ECG provides some, but limited information about the electrical status of the heart. This article describes a method to determine both endocardial and epicardial activation of the heart of an individual ...
Dube Preeti - - 2011
What begins with a failing heart, unable to sustain adequate renal perfusion and metabolic needs of the tissues it serves becomes a systemic illness whose origins are rooted in neurohormonal activation. This unwanted homeostatic stressor response, an adaptation gone awry, has pathologic consequences. It involves endocrine properties of effector hormones ...
Chaturvedi Vivek - - 2011
We describe an uncommon case of typical flutter with symptomatic sinus node dysfunction, in which a permanent junctional rhythm developed following ablation of the cavo-tricuspid isthmus. This rhythm activated the right atrium in counter clockwise manner thus providing spontaneous proof of unidirectional isthmus block, a phenomenon that is usually demonstrated ...
Lee Hee-Woo - - 2011
Non-reentrant focal tachycardias occur spontaneously, facilitated by catecholamine infusion, but they cannot be initiated or terminated with programmed stimulation. These tachycardias exhibit early activation before the QRS, however, do not typically show the mid-diastolic potential that is crucial for reentrant tachycardia maintenance. Electrophysiological studies are useful for distinguishing focal from ...
Niederer Steven A SA Imaging Sciences & Biomedical Engineering Division, King's College London, London, United Kingdom. - - 2012
Response to cardiac resynchronization therapy (CRT) is reduced in patients with posterolateral scar. Multipolar pacing leads offer the ability to select desirable pacing sites and/or stimulate from multiple pacing sites concurrently using a single lead position. Despite this potential, the clinical evaluation and identification of metrics for optimization of multisite ...
Yan Huimin - - 2011
Sudden cardiac events are the leading cause of line-of-duty firefighter deaths, but little information exists elucidating the physiologic responses. Wave intensity (WI) is a new hemodynamic index that provides information about the dynamic behavior of the heart and the vascular system and their interaction. The larger first peak wave (W1) ...
Numata Ayaka - - 2012
Chronic left ventricular myocardial infarction (LVMI) promotes atrial and pulmonary veins (PV) sympathetic nerve sprouting. To test the hypothesis that sympathetic stimulation with tyramine initiates atrial fibrillation (AF) by early after depolarization (EAD)-mediated triggered activity at the left atrial PV (LAPV) junction. LVMI was created in 6 dogs and 6 ...
Puzianowska-Ku┼║nicka Monika - - 2011
Women live longer than men; this can be attributed in part to the function of estrogens. In premenopausal women 17β-estradiol (E2) is produced mainly by the ovaries. Extra-ovarian sources of this hormone comprise adipose tissue, breast tissue, bone, leukocytes, heart, testes, prostate, adrenal tissues, and some brain structures. E2 exerts ...
Edwards Lindsay M - - 2011
The ratio of myocardial phosphocreatine (PCr)/ATP reflects the balance of energy consumption and energy supply in the heart. It is reduced in a range of important physiological conditions including during and after acute hypoxia, after a prolonged visit to high-altitude, and in those suffering from both type 2 diabetes mellitus ...
Pchejetski Dmitri - - 2011
AimsActivation of cardiac fibroblasts and their differentiation into myofibroblasts is a key event in the progression of cardiac fibrosis that leads to end-stage heart failure. Apelin, an adipocyte-derived factor, exhibits a number of cardioprotective properties; however, whether apelin is involved in cardiac fibroblast activation and myofibroblast formation remains unknown. The ...
Chen Qun - - 2011
Ubiquitous calpains (calpain I and II) are generally recognized as cytosolic proteins. Recently, mitochondrial localized calpain I (μ-calpain) has been identified. Activation of mito-μ-calpain cleaves apoptosis inducing factor (AIF), a flavoprotein located within the mitochondrial intermembrane space, in liver mitochondria, but not in brain mitochondria. We first tested if activation ...
Oyama Mark A - - 2011
Diuretics are a mainstay of therapy in dogs with heart failure. In dogs with advanced heart failure, moderate to high doses of loop diuretics such as furosemide are used with diminishing effects as profound activation of neuroendocrine systems promote signs of congestive heart failure. The loop diuretic torsemide has several ...
Miller Clint L - - 2011
Cardiac fibroblasts become activated and differentiate to smooth muscle-like myofibroblasts in response to hypertension and myocardial infarction (MI), resulting in extracellular matrix (ECM) remodeling, scar formation and impaired cardiac function. cAMP and cGMP-dependent signaling have been implicated in cardiac fibroblast activation and ECM synthesis. Dysregulation of cyclic nucleotide phosphodiesterase (PDE) ...
Stessman-Lande Irit - - 2011
Abstract The relationship of physical activity (PA) and cardiac function in the oldest old remains unclear. The objective of this study was to evaluate the relationship between PA and cardiac structure and function, in the oldest old. Subjects were recruited from the Jerusalem Longitudinal Cohort Study that was initiated in ...
Zhang Tong - - 2012
The Mas receptor is a class I G-protein-coupled receptor that is expressed in brain, testis, heart, and kidney. The intracellular signaling pathways activated downstream of Mas are still largely unknown. In the present study, we examined the expression pattern and signaling of Mas in the heart and assessed the participation ...
Kalogeropoulos Andreas P - - 2012
Elevated levels of circulating proinflammatory cytokines and adipokines have been repeatedly associated with increased risk for clinically manifest (Stage C) heart failure in large cohort studies. However, the role of low-grade, subclinical inflammatory activity in the transition from risk factors (Stage A heart failure) to structural heart disease (Stage B ...
Kandalam Vijay - - 2011
Background-Remodeling of the extracellular matrix (ECM) is a key aspect of myocardial response to biomechanical stress and heart failure. Tissue inhibitors of metalloproteinases (TIMPs) regulate the ECM turnover through negative regulation of matrix metalloproteinases (MMPs), which degrade the ECM structural proteins. Tissue inhibitor of metalloproteinases 2 is unique among TIMPs ...
Shimano Masayuki - - 2011
Factors secreted by the heart, referred to as "cardiokines," have diverse actions in the maintenance of cardiac homeostasis and remodeling. Follistatin-like 1 (Fstl1) is a secreted glycoprotein expressed in the adult heart and is induced in response to injurious conditions that promote myocardial hypertrophy and heart failure. The aim of ...
Russell Kristoffer - - 2011
During left bundle branch block (LBBB) electromechanical delay (EMD), defined as time from regional electrical activation (REA) to onset shortening, is prolonged in the late activated left ventricular (LV) lateral wall compared to the septum. This leads to greater mechanical relative to electrical dyssynchrony. The aim of this study was ...
Han Chengzong - - 2012
Single-beat imaging of myocardial activation promises to aid in both cardiovascular research and clinical medicine. In the present study we validate a three-dimensional (3D) cardiac electrical imaging (3DCEI) technique with the aid of simultaneous 3D intracardiac mapping to assess its capability to localize endocardial and epicardial initiation sites and image ...
Heusch Gerd - - 2011
Rationale:Timely restoration of coronary blood flow is the only way to salvage myocardium from infarction, but reperfusion per se brings on additional injury. Such reperfusion injury and the resulting size of myocardial infarction is attenuated by ischemic postconditioning, ie, the repeated brief interruption of coronary blood flow during early reperfusion. ...
Leenders Geert E - - 2012
Response to cardiac resynchronization therapy depends both on dyssynchrony and (regional) contractility. We hypothesized that septal deformation can be used to infer integrated information on dyssynchrony and regional contractility, and thereby predict cardiac resynchronization therapy response. In 132 cardiac resynchronization therapy candidates with left bundle branch block (LBBB)-like electrocardiogram morphology ...
Li Wenwen - - 2011
Implantable device therapy of atrial fibrillation (AF) is limited by pain from high-energy shocks. We developed a low-energy multistage defibrillation therapy and tested it in a canine model of AF. AF was induced by burst pacing during vagus nerve stimulation. Our novel defibrillation therapy consisted of 3 stages: stage (ST) ...
Zarzoso M - - 2011
The purpose of this study is to test the role that parasympathetic postganglionic neurons could play on the adaptive electrophysiological changes produced by physical training on intrinsic myocardial automatism, conduction and refractoriness. Trained rabbits were submitted to a physical training protocol on treadmill during 6 weeks. The electrophysiological study was performed ...
Chen Shanshan - - 2011
It has been demonstrated that excessively activated endoplasmic reticulum stress (ERS) is related to myocardial injury. The study was designed to explore the possible role of sulfur dioxide (SO(2)) in protecting excessively activated ERS in rats with isoproterenol (ISO)-induced myocardial injury. Wistar rats were randomly divided into control, ISO, and ...
Parlakpinar Hakan - - 2011
The renin-angiotensin system (RAS) plays a major role in regulating the cardiovascular system, and disorders of the RAS contribute largely to the cardiac pathophysiology, including myocardial ischemia-reperfusion (MI/R) injury. Two subtypes of angiotensin II (Ang II) receptors have been defined on the basis of their differential pharmacological properties. The current ...
Chen Yi-Hong - - 2011
Ischemic postconditioning (I-postC) is a newly discovered and more amenable cardioprotective strategy capable of protecting the myocardium from ischemia/reperfusion (I/R) injury. Endoplasmic reticulum (ER) is a principal site for secretary protein synthesis and calcium storage. Myocardial I/R causes ER stress and emerging studies suggest that the cardioprotection has been linked ...
Vähäsilta Tommi - - 2011
Retrograde delivery is associated with inadequate perfusion of cardioplegia to all regions of the heart, but the effects on cardiomyocyte death and functional outcome remain unknown. We compared antegrade and retrograde cardioplegia in a randomized clinical trial to see whether it has effect on cardiomyocyte apoptosis and left ventricular function. ...
Chen Jiawei - - 2011
Cardiac fibroblasts play a pivotal role in cardiac remodeling. In response to various pro-fibrotic stimuli,such as pro-inflammatory cytokines,anoxia-reoxygenation and pressure overload as well as aging,cardiac fibroblasts undergo proliferation,migration and activation,leading to the accumulation of extracellular matrix components and increased thickness and stiffness of heart. The ligands for peroxisome proliferator-activated receptor ...
Díaz José F - - 2011
INTRODUCTION AND OBJECTIVES: The Working Group on Cardiac Catheterization and Interventional Cardiology presents on a yearly basis a report on the data collected for the national registry. This information displays how procedures are distributed throughout Spain and makes comparisons with other countries feasible. METHODS: Institutions render their data voluntarily (online) ...
Jastrzebski Marek - - 2011
Background:  Left ventricular (LV)-only pacing has a significant effect on delay in depolarization of parts of the ventricles that are likely oversensed in the right atrial channel. The study aimed to assess the impact of ventricular activation sequence on QRS oversensing and far-field endless-loop pacemaker tachycardia (ELT) in patients who ...
Robledo-Nolasco Rogelio - - 2011
Pacemaker-mediated tachycardia (PMT) remains a clinical problem in patients with dual-chamber pacemaker despite technological advances. The onset mechanism of this tachycardia is sensing of retrograde atrial activation after ventricular stimulation. Repeated retrograde conduction perpetuates tachycardia. Postventricular atrial refractory period prolongation has been used for prevention of PMT, but this is ...
Lichtenauer Michael - - 2011
Heart failure following acute myocardial infarction (AMI) is a major cause of morbidity and mortality. Our previous observation that injection of apoptotic peripheral blood mononuclear cell (PBMC) suspensions was able to restore long-term cardiac function in a rat AMI model prompted us to study the effect of soluble factors derived ...
Shen Mark J - - 2011
The past 5 years have seen great advances in the knowledge of neural mechanisms of atrial arrhythmogenesis. Direct autonomic nerve recordings demonstrate that simultaneous sympathovagal discharges and intrinsic cardiac nerve activities are common triggers of paroxysmal atrial tachycardia and atrial fibrillation. While activity of the autonomous nervous system (ANS) is ...
Huang Cheng-Hsiung - - 2011
BACKGROUND: We previously reported brief pressure overload of the left ventricle reduced myocardial infarct size. The role of adenosine receptors was investigated in this study. METHODS: Pressure overload was achieved by two 10-minute partial snaring of the ascending aorta. Systolic left ventricular pressure was raised 50% above baseline value. Ischemic ...
Kasius Kristel M - - 2011
A patient is described who previously had daily complaints of angina pectoris, yet no longer experienced chest pain after an ischemic stroke of the right hemisphere, despite several recorded episodes of electrocardiographic changes and an elevation of cardiac enzymes compatible with myocardial ischemia. The cingulate gyrus is involved in spatial ...
Sanchez Jose A - - 2011
A transient reduction of cell coupling during reperfusion limits myocardial necrosis, but little is known about its arrhythmogenic effects during ischemia-reperfusion. Thus, we have analyzed the effect of an extreme reduction in the number of gap junction channels or in their unitary conductance on ventricular arrhythmias during myocardial ischemia-reperfusion. Available ...
Wang Xuejun X Division of Basic Biomedical Sciences, Protein Quality Control and Degradation Research Center, Sanford School of Medicine, University of South Dakota, Vermillion, South Dakota 57069, USA. - - 2011
The ubiquitin-proteasome system (UPS) is responsible for the degradation of most cellular proteins. Alterations in cardiac UPS, including changes in the degradation of regulatory proteins and proteasome functional insufficiency, are observed in many forms of heart disease and have been shown to play an important role in cardiac pathogenesis. In ...
Saghy Laszlo - - 2011
BACKGROUND: Ablation of persistent atrial fibrillation (AF) may require adjunctive methods of substrate modification. Both ablation targeting complex fractionated atrial electrograms (CFAE) recorded during AF and fractionated electrograms recorded during sinus rhythm (SRF) have been described. However, the relationship of CFAE to SRF is unclear. METHODS: Twenty patients (age 62±9 ...
Lu J J Central Arkansas Veterans Healthcare System, Department of Internal Medicine, Division of Cardiovascular Medicine, University of Arkansas for Medical Sciences, Little Rock, AR 72212, - - 2012
We hypothesized that lectin-like oxidized LDL receptor-1 (LOX-1) deletion may inhibit oxidative stress signals, reduce collagen accumulation and attenuate cardiac remodeling after chronic ischemia. Activation of LOX-1 plays a significant role in the development of inflammation, apoptosis and collagen signals during acute ischemia. Wild-type and LOX-1 knockout (KO) mice were ...
Yang Hui - - 2011
Cardiovascular disorders, such as myocardial infarction (MI) are the leading causes of mortality in the world. This paper presents an approach that uses novel spatio-temporal patterns of the vectorcardiogram (VCG) signals for the identification of various types of MI. In contrast to the traditional electrocardiogram (ECG) approaches, the 3D cardiac ...
Miller Marc A - - 2011
Our goal was to investigate the effects of percutaneous left ventricular assist device (pLVAD) support during catheter ablation of unstable ventricular tachycardia (VT). Mechanical cardiac support during ablation of unstable VT is being increasingly used, but there is little available information on the potential hemodynamic benefits. Twenty-three consecutive procedures in ...
Palomares Sara Morales - - 2011
Despite considerable research that has contributed to a better understanding of the pathophysiology of stroke, translation of this knowledge into effective therapies has largely failed. The only effective treatment for ischemic stroke is rapid recanalization of an occluded vessel by dissolving the clot with tissue plasminogen activator (tPA). However, stroke ...
Zhang Yin Hua YH Department of Physiology, Seoul National University, College of Medicine, Seoul, Republic of - - 2012
Constitutive nitric oxide synthases (NOSs) are ubiquitous enzymes that play a pivotal role in the regulation of myocardial function in health and disease. The discovery of both a neuronal NOS (nNOS) and an endothelial NOS (eNOS) isoform in the myocardium and the availability of genetically modified mice with selective eNOS ...
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