Search Results
Results 201 - 250 of 1695
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Lin Jing J Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN 55905, - - 2009
Monocyte chemoattractant proteins (MCPs) play an important role in mediating inflammatory processes. Hypertension (HTN) is associated with inflammation as well as impaired cardiac microcirculatory function and structure, but the contribution of MCPs to these alterations remained unclear. This study tested the hypothesis that MCPs regulate cardiac microvascular function and structure ...
Jung Jae-Hun - - 2009
Medical treatments of coronary myocardial bridging (CMB) generally include beta-blockers and calcium channel blockers. Nitrates are avoided because symptoms may worsen. Nicorandil is a hybrid of a nitrate and a potassium channel opener. However, the effect of nicorandil on CMB is unknown. We analyzed nicorandil reactivity at the site with ...
Palmiero Pasquale - - 2009
Persistent non-valvular atrial fibrillation (NVAF) is associated with an increased risk of cardiovascular events such as stroke, and its rate is expected to rise because of the ageing population. The absolute rate of stroke depends on age and comorbidity. Risk stratification for stroke in patients with NVAF derives from populations ...
Recio-Mayoral Alejandro A Medical Research Council Clinical Sciences Centre and National Heart and Lung Institute, Imperial College School of Medicine, London W12 0NN, - - 2009
To demonstrate that exposure to chronic inflammation results in coronary microvascular dysfunction (CMD). Using positron emission tomography, resting and hyperaemic (adenosine, 140 microg/kg/min) myocardial blood flow (MBF) was measured in 25 patients with systemic lupus erythematosus (SLE) or rheumatoid arthritis (RA). Coronary flow reserve (CFR) was calculated as adenosine/resting MBF. ...
Vermeltfoort Ilse A C - - 2009
Many patients suffer from persistent angina due to coronary vasospasm despite optimal medical treatment. We treated a 46-year-old patient with severe and treatment-resistant coronary vasospasm with the endothelin-receptor antagonist bosentan. Using oxygen-15-labelled water in conjunction with oxygen 15-labelled carbon monoxide positron emission tomography (PET), we measured an impaired coronary flow ...
Knaapen Paul P Department of Cardiology, VU University Medical Center, Amsterdam, The Netherlands. - - 2009
Coronary microvascular dysfunction is a topic that has recently gained considerable interest in the medical community owing to the growing awareness that microvascular dysfunction occurs in a number of myocardial disease states and has important prognostic implications. With this growing awareness, comes the desire to accurately assess the functional capacity ...
Del Valle-Mondragón L - - 2009
The aim of this study was to investigate the biodynamic effects of vulgarenol, a sesquiterpene isolated from Magnolia grandiflora flower petals and its possible mechanism on the Langendorff isolated and perfused heart model. Vulgarenol (5 microm) caused a statistically significant decrease in coronary vascular resistance (15.21 +/- 6.00 dyn s ...
Osto Elena - - 2009
BACKGROUND: Determination of coronary flow reserve (CFR) is increasingly being used in cardiac allograft vasculopathy (CAV). We aimed to identify determinants of CFR in heart transplantation (HT). METHODS: CFR was measured by transthoracic echocardiography in 119 HT recipients (97 men, 22 women; 50 +/- 12 years of age at HT ...
Druz Regina S - - 2009
More than 7 million stress perfusion studies are performed in the United States annually, 44% with pharmacological vasodilator stress agents. Both adenosine and dipyridamole are nonselective coronary vasodilators that are commonly used for stress perfusion imaging. These agents are safe and provide an effective means to diagnose coronary artery disease. ...
Fineschi Massimo - - 2011
A 56-year old man was admitted for precordial pain associated with dyspnea and evidence of myocardial ischemia on ECG and cardiac ultrasound. His previous history included an episode of left apical ballooning five years before. At angiography, no evidence of significant epicardial coronary artery disease was manifest. Interestingly, both coronary ...
Raichlin Eugenia - - 2009
AIMS: The aim of this study was to evaluate coronary vasomotor function in cardiac transplant recipients maintained on sirolimus (SRL)- or cyclosporin (CyA)-based immunosuppression. METHODS AND RESULTS: Endothelium-independent response to intracoronary nitroglycerin and adenosine and endothelium-dependent response to intracoronary acetylcholine (Ach) were assessed in 15 SRL- and 21 CyA- treated ...
Koivuviita Niina - - 2009
BACKGROUND: Even minor renal dysfunction is a powerful cardiovascular risk factor. The abnormalities in coronary and peripheral artery function in different stages of chronic kidney disease (CKD) remain poorly understood. Our aim was to test by a positron emission tomography (PET)-based method whether microvascular dysfunction, an early marker of coronary ...
Zhang Rui - - 2009
Lysophosphatidylcholine (LPC), a hydrolysis product of phospholipid degradation, accumulates in the ischemic myocardium. Using isolated hearts or rat coronary septal arteries, we tested the impact of LPC in modulating basal function or the responses to vasoactive agents. Sustained perfusion of hearts with LPC augmented coronary perfusion pressure (CPP) and reduced ...
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 ...
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