Search Results
Results 201 - 250 of 1682
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Bender Shawn B - - 2009
Onset of the combined metabolic syndrome (MetS) is a complex progressive process involving numerous cardiovascular risk factors. Although patients with established MetS exhibit reduced coronary flow reserve and individual components of the MetS reduce microvascular vasodilation, little is known concerning the impact of early-stage MetS on the mechanisms of coronary ...
Simonis Gregor - - 2009
OBJECTIVE: Chronic adenosine A2b receptor stimulation has been shown to prevent ventricular remodelling after myocardial infarction (MI). We hypothesized that this effect is due to the inhibition of cardiac myocyte apoptosis in the myocardium remote from the infarction. METHODS: Rats were subjected to MI by LAD ligation in situ. Some ...
Hage Fadi G - - 2009
BACKGROUND: Adenosine and regadenoson increase heart rate (HR) when used as stress agents to produce coronary hyperemia due to direct sympathetic stimulation. We hypothesized that the HR response will be lower in patients with than in those without diabetes mellitus (DM). METHODS: We studied the HR response (percentage maximal increase) ...
Goette Andreas - - 2009
Patients with paroxysmal atrial fibrillation (AF) often present with typical angina pectoris and mildly elevated levels of cardiac troponin (non ST-segment elevation myocardial infarction) during an arrhythmic event. However, in a large proportion of these patients, significant coronary artery disease is excluded by coronary angiography. Here we explored the potential ...
Raichlin Eugenia - - 2009
The aim of the study was to evaluate the features and mechanism of cardiac allograft coronary endothelial dysfunction. Coronary blood flow and epicardial coronary artery diameter response to intracoronary acetylcholine and N(G)-monomethyl-l-arginine were assessed in 19 cyclosporine-treated heart transplant recipients with normal coronary angiograms (3.8 +/- 2.3 years after transplantation) ...
Discigil Berent - - 2009
Prostacyclin (PgI(2)) and endothelium-derived nitric oxide (EDNO) are produced by the arterial and venous endothelium. In addition to their vasodilator action on vascular smooth muscle, both act together to inhibit platelet aggregation and promote platelet disaggregation. EDNO also inhibits platelet adhesion to the endothelium. EDNO and PgI(2) have been shown ...
Liu Yanping Y National Center for Research Resources, NIH, Bethesda, MD, - - 2009
Myocardial perfusion is regulated by a variety of factors that influence arteriolar vasomotor tone. An understanding of the physiological and pathophysiological factors that modulate coronary blood flow provides the basis for the judicious use of medications for the treatment of patients with coronary artery disease. Vasomotor properties of the coronary ...
Ichiki Hitoshi - - 2010
Hyperglycemia upon hospital admission in patients with acute myocardial infarction is associated with the no-reflow phenomenon after successful reperfusion, and increased mortality. However, the mechanism underlying this phenomenon remains unclear. Therefore, the aim of this study was to characterize coronary hemodynamics in a homogenous group of non-diabetic patients without coronary ...
Asfar Pierre - - 2009
During advanced vasodilatory shock, arginine vasopressin (AVP) is increasingly used to restore blood pressure and thus to reduce catecholamine requirements. The AVP-related rise in mean arterial pressure is due to systemic vasoconstriction, which, depending on the infusion rate, may also reduce coronary blood flow despite an increased coronary perfusion pressure. ...
LeBlanc A J AJ Center for Cardiovascular and Respiratory Sciences, West Virginia University School of Medicine, Morgantown 26506-9105, West Virginia, - - 2009
Exposure to fine particulate matter (PM, mean aerodynamic diameter <or=2.5 microm) has been shown to be a risk factor for cardiovascular disease mortality and may contribute to acute coronary events such as myocardial infarction (MI). There is sufficient reason to believe that smaller particles, such as nanoparticles, might be even ...
Kasiganesan Harinath - - 2009
Two l-nucleosides, l-3'-amino-3'-deoxy-N(6)-dimethyladenosine (l-3'-ADMdA) 1, previously synthesized in our laboratory, and the novel l-3'-amino-3'-deoxy-N(6)-methyladenosine-5'-N-methyluronamide (l-3'-AM-MECA) 2 were evaluated in an ischemia/reperfusion model on Langendorff perfused mouse heart. l-3'-ADMdA 1 was found to enhance functional recovery from ischemia (32.2+/-3.7cm H(2)O/s % rate pressure product, compared to 21.3+/-1.4 for the control and ...
ZHANG Ya-chen - - 2008
OBJECTIVE: To study the effect of Shengmai injection (, SMI) on vascular endothelial and heart functions in coronary heart disease patients complicated with diabetes mellitus (CHD-DM). METHODS: One hundred and twenty patients with CHD-DM, their diagnosis confirmed by coronary arteriography, were equally randomized into a control group treated with conventional ...
Gergs Ulrich - - 2009
The actions of adenosine in the human atrium are of clinical relevance, for instance, to stop supraventricular arrhythmias. The purpose of the present study was to re-evaluate the inotropic effect of adenosine in the human atrium. We studied the effect of adenosine (cumulatively applied) on force of contraction in isolated ...
Böhm Felix - - 2008
Endothelin (ET)-1 receptor blockade improves endothelial function in the forearm of patients with atherosclerosis. The aim was to investigate whether intracoronary ET receptor blockade improves coronary endothelial function and increases blood flow in patients with coronary artery disease. Ten patients received a 60-minute infusion of either the selective ETA receptor ...
Kunadian Vijayalakshmi - - 2008
Although percutaneous coronary intervention restores optimal epicardial blood flow in most cases, abnormal myocardial perfusion may still persist. This might be as a result of macro and microembolization, neutrophil plugging, vasoconstriction, myocyte contracture, local intracellular and interstitial edema, intramural haemorrhage, and endothelial blistering. Local delivery of intracoronary pharmacotherapy via the ...
Bartoli Carlo R - - 2009
Experimental and observational studies have demonstrated that short-term exposure to ambient particulate matter (PM) exacerbates myocardial ischemia. We conducted this study to investigate the effects of concentrated ambient particles (CAPs) on myocardial blood flow during myocardial ischemia in chronically instrumented conscious canines. Eleven canines were instrumented with a balloon occluder ...
Shimokawa Hiroaki - - 2008
Ischemic heart disease is the leading cause of morbidity and mortality in a worldwide epidemic. Myocardial ischemia is characterized by an imbalance between myocardial oxygen supply and demand, causing cardiac dysfunction, arrhythmias, myocardial infarction, and sudden death. Various clinical ischemic manifestations are caused by obstruction of coronary blood flow by ...
Kumar Gautam - - 2008
OBJECTIVE: Coronary endothelial dysfunction is the early stage of coronary artery disease. We documented the incidence and type of electrocardiographic changes during acetylcholine-induced coronary endothelial dysfunction. METHODS: Endothelial function studies were performed with intracoronary injections of 10(-6), 10(-5), and 10(-4) mmol/l acetylcholine. Twelve-lead electrocardiograms were obtained at baseline, after each ...
Kovacs Daniela - - 2008
Approximately 6 million cardiac stress tests are performed annually in the United States, of which 2.4 million are pharmacologic stress tests using agents such as adenosine. Adenosine induces differential coronary hyperemia in normal coronary arteries versus coronary arteries with atherosclerosis, allowing single photon emission computed tomography (SPECT) imaging to identify ...
Krüger Dietmar - - 2008
OBJECTIVES: Aim of our study was to evaluate the coronary flow patterns and therapeutic effects of nitroglycerin (NTG) in patients with isolated large coronary artery aneurysms (CA). CA are defined as nonobstructive lesions of the epicardial coronary arteries with a luminal dilation >or=two-fold of the normal diameters. The pathophysiology of ...
Zhao Jing-Lin - - 2008
It has been verified that adenosine can attenuate myocardial no-reflow. However, the effects of adenosine on adenosine triphosphate-sensitive K+ (KATP) channel and endothelin-1 (ET-1) are unknown. METHODS: Forty mini-swines were randomized into 5 study groups: 8 in the control group, 8 in the adenosine pretreatment group, 8 in the glibenclamide ...
Hamilton Garun S - - 2008
Patients with obstructive sleep apnea (OSA) and coronary artery disease have a poor long-term prognosis. It is unknown whether the coronary blood flow (CBF) response to OSA is appropriate for myocardial metabolic requirements. Therefore, CBF was assessed during OSA, before and after the development of coronary artery endothelial dysfunction. University ...
Kolyva Christina - - 2008
A novel single-point technique to calculate local arterial wave speed (SPc) has recently been presented and applied in healthy human coronary arteries at baseline flow. We investigated its applicability for conditions commonly encountered in the catheterization laboratory. Intracoronary pressure (P(d)) and Doppler velocity (U) were recorded in 29 patients at ...
Ikonomidis Ignatios - - 2008
BACKGROUND: Interleukin-1 increases nitrooxidative stress. We investigated the effects of a human recombinant interleukin-1a receptor antagonist (anakinra) on nitrooxidative stress and vascular and left ventricular function. METHODS AND RESULTS: In an acute, double-blind trial, 23 patients with rheumatoid arthritis were randomized to receive a single injection of anakinra (150 mg ...
Drelicharz Lukasz - - 2008
OBJECTIVE: The aim of the present work was to analyze coronary endothelial function in the transgenic mouse model of dilated cardiomyopathy (Tgalphaq*44 mice). METHODS: Coronary vasodilatation, both NO-dependent (induced by bradykinin) and PGI(2)-dependent (induced by acetylcholine), was assessed in the isolated hearts of Tgalphaq*44 and FVB mice. Cardiac function was ...
Ruel Marc M Division of Cardiac Surgery, University of Ottawa, Ottawa, Ontario, Canada. - - 2008
Endothelial dysfunction and decreased nitric oxide bioavailability may explain why therapeutic angiogenesis and cell therapy have mostly failed in humans. Building from previous large animal work, the Phase I Endothelial Modulation in Angiogenic Therapy trial tested the hypothesis that L-arginine, a nitric oxide donor, may be safe and effective in ...
Lauer T - - 2008
BACKGROUND AND OBJECTIVES: Oxidized LDL cholesterol and cytokines increase arginase and decrease nitric oxide (NO) synthase expression in human endothelial cells, leading to a decrease in NO production. In arteriosclerotic plaques, characterized by increased oxidized LDL and cytokine levels, a sustained local NO reduction might enhance sensitivity of the downstream ...
Teng Bunyen B Department of Physiology and Pharmacology, West Virginia University Health Sciences Center, Morgantown, WV 26506-9104, - - 2008
In this study, we looked into possible compensatory changes of other adenosine receptors (ARs) in A(2A) genetic knockout mice (A2AKO) as well as the functional role of nitric oxide (NO) in A(2A) AR-mediated vasodilation. Gene expression of ARs from coronary arteries of A(2A) AR wild type mice (A2AWT) and A2AKO ...
Wikström Johannes - - 2008
For an accurate estimate of volumetric coronary flow reserve (CFR) using Doppler-assessed flow velocity measurement, it is important to take into consideration potential diameter change during coronary hyperemia. Using ultrasound techniques, left coronary artery (LCA) flow velocity and LCA lumen diameter (LCA(D)) were measured simultaneously for the first time to ...
Maurer Gereon - - 2008
As shown previously, adenosine and the adenine nucleotides cause a rapid increase in heart rate (f(H)) and haemolymph velocity (v(HL)) when infused into intact American lobster (Homarus americanus). Here we compare the effects of adenosine and adenine nucleotides on different heart preparations in order to gain insight into their sites ...
Ashikaga Takashi - - 2008
Endothelial dysfunction occurs in hyperinsulinemia (HI). Coronary microcirculation responses to vasoactive agents are examined in 57 patients with angiographically normal coronary arteries. Patients were divided into 2 groups, 37 with normoinsulinemia (NI) and 20 with HI based on results of a 75-g oral glucose tolerance test. Epicardial artery vasoactivity in ...
de Beer Vincent J - - 2008
Several studies have indicated an interaction between the renin-angiotensin (ANG II) system and endothelin (ET) in the regulation of vascular tone. Previously, we have shown that both ET and ANG II exert a vasoconstrictor influence on the coronary resistance vessels of awake normal swine. Here, we investigated whether the interaction ...
Sorop Oana - - 2008
Distal to a chronic coronary artery stenosis, structural remodeling of the microvasculature occurs. The microvascular functional changes distal to the stenosis have not been studied in detail. We tested the hypothesis that microvascular structural remodeling is accompanied by altered regulation of coronary vasomotor tone with increased responsiveness to endothelin-1. Vasomotor ...
Meimoun Patrick - - 2008
Transthoracic Doppler echocardiography, introduced in the echo-lab in recent last years, to measure coronary flow and coronary flow reserve, is a very attractive tool, totally non-invasive, and easily available at bedside. This review summarizes the actual possibilities of this tool, its multiple potential clinical applications and diagnostic insights, and its ...
Wu Gui Fu - - 2008
BACKGROUND: Nesiritide is recombinant human B-type natriuretic peptide, used in the treatment of decompensated heart failure. Ischemic heart disease remains the major underlying cause for congestive heart failure, however, the effects of intravenous and intracoronary nesiritide on coronary circulation have not been adequately studied. METHODS: Fourteen Yorkshire pigs were used ...
Kaneda Hideaki - - 2009
Previous studies demonstrate impairment of endothelial-dependent vasodilation after ischemia/reperfusion (I/R). Though we have demonstrated that inhibition of delta protein kinase C (delta PKC) at reperfusion reduces myocyte damage and improves cardiac function in a porcine acute myocardial infarction (AMI) model, impact of the selective delta PKC inhibitor on epicardial coronary ...
Nguyen Patricia K - - 2008
BACKGROUND: Impaired coronary vasodilation to both endothelial-dependent and endothelial-independent stimuli have been associated with atherosclerosis. Direct measurement of coronary vasodilation using x-ray angiography or intravascular ultrasound is invasive and, thus, not appropriate for asymptomatic patients or for serial follow-up. In this study, high-resolution coronary cardiovascular magnetic resonance (CMR) was used ...
Leone Maria Cristina - - 2008
The coronary slow flow phenomenon (CSFP) is an angiographic finding that is characterised by delayed progression of the contrast medium during coronary angiography. The mechanism of this phenomenon remains unknown. In the present paper, we revise the current evidence regarding this phenomenon and discuss recent findings from our group reporting ...
Forman Mervyn B - - 2008
Angiographic evidence of impaired tissue perfusion, known as the "no-reflow" phenomenon, is a serious complication of percutaneous coronary intervention-one that is associated with increased mortality rates. Adenosine is an endogenous nucleoside that attenuates many of the mechanisms that are responsible for no-reflow. Herein, we report the cases of 4 patients ...
Buhr Christiane - - 2008
Myocardial perfusion studies use either physical exercise or pharmacologic vasodilator stress to induce maximum myocardial hyperemia. Adenosine and dipyridamole are the most commonly used agents to induce coronary arterial vasodilation for myocardial perfusion imaging. Both cause frequent undesirable side-effects. Because of its ultrashort half-life, adenosine must be administered by constant ...
Boodhwani Munir M Division of Cardiothoracic Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Mass 02215, - - 2008
Statins, 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, used routinely in patients with coronary disease, can improve endothelial function but can have biphasic and dose-dependent effects on angiogenesis. In vitro evidence suggests that the proangiogenic effects of statins are linked to activation of Akt, a mediator of endothelial cell survival and an ...
Yukisada, Kimihiko
Thesis--University of Tsukuba, D.M.S.(A), no. 569, 1988. 3. 25
Du Lei - - 2007
BACKGROUND: Endogenous nitric oxide and adenosine increase simultaneously to keep the balance of energy demand and supply when the oxygen supply is insufficient, which suggests that nitric oxide and adenosine might exert a synergistic myoprotection during tissue hypoxia. In this study, we tested this hypothesis utilizing a canine model of ...
Saitoh Shu-ichi - - 2007
We have observed that hydrogen peroxide (H2O2), the dismutated product of superoxide, is a coronary metabolic dilator and couples myocardial oxygen consumption to coronary blood flow. Because the chemical activity of H2O2 favors its role as an oxidant, and thiol groups are susceptible to oxidation, we hypothesized that coronary metabolic ...
Grossini Elena - - 2008
We planned to determine the primary effects and mechanisms of urocortin II, a member of the corticotrophin-releasing factor (CRF) family highly expressed in the cardiovascular system, on coronary blood flow and myocardial function in vivo. Urocortin II was infused into the left anterior descending coronary artery in 25 anaesthetized pigs ...
Ayoub Iyad M - - 2007
OBJECTIVE: To investigate whether sodium-hydrogen exchanger isoform-1 (NHE-1) inhibition attenuates myocardial injury during resuscitation from ventricular fibrillation through effects on energy metabolism, using an open-chest pig model in which coronary perfusion was controlled by extracorporeal circulation. DESIGN: Randomized controlled animal study. SETTING: University research laboratory. SUBJECTS: Male domestic pigs. INTERVENTIONS: ...
Yada Toyotaka - - 2007
OBJECTIVES: We examined whether endogenous hydrogen peroxide (H2O2) is involved in pacing-induced metabolic vasodilation in vivo. BACKGROUND: We have previously demonstrated that endothelium-derived H2O2 is an endothelium-derived hyperpolarizing factor in canine coronary microcirculation in vivo. However, the role of endogenous H2O2 in metabolic coronary vasodilation in vivo remains to be ...
Fulop Tibor - - 2007
OBJECTIVES: We hypothesized that simultaneous presence of obesity and hypertension activates adaptive vascular mechanisms affecting dilations of human coronary arterioles. METHODS AND RESULTS: Agonist-induced dilations were assessed in isolated pressurized coronary arterioles from patients (n=38) who underwent cardiac surgery. Among normotensives we found that dilations to bradykinin (BK) and the ...
del Valle-Mondragón Leonardo - - 2007
Vulgarenol, a sesquiterpene isolated from Magnolia grandiflora flower petals, decreased coronary vascular resistance in the Langendorff isolated and perfused heart model, when compared to the control group [(15.2 x 10(7) +/- 1.0 x 10(7)) dyn s cm(-5) vs. (36.8 x 10(7) +/- 1.2 x 10(7)) dyn s cm(-5)]. Our data ...
Nitenberg Alain - - 2007
OBJECTIVE: The aim of this study was to compare the ability of intracoronary adenosine (ADE) and postocclusion hyperemia (PH) to cause maximal hyperemia in humans. BACKGROUND: The current clinical standard for induction of maximal coronary hyperemia is intracoronary ADE. However, animal studies have shown that maximal hyperemia was not achieved ...
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