Search Results
Results 251 - 300 of 1700
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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 ...
Fontes-Sousa Ana Patrícia - - 2007
Urotensin II (U-II) is a cyclic peptide that may be involved in cardiovascular dysfunction. In the present study, the acute effects of U-II on diastolic properties of the myocardium were investigated. Increasing concentrations of U-II (10(-8) to 10(-6) M) were added to rabbit papillary muscles in the absence (n = ...
Lee Chii-Ming - - 2008
OBJECTIVES: We aimed to determine whether epicardial and intramyocardial arteries were involved concordantly in early cardiac allograft vasculopathy. METHODS: Thirty consecutive recipients who had received cardiac transplantation more than 1 year before and had a normal coronary angiogram were enrolled for intravascular ultrasound (IVUS), fractional flow reserve, coronary flow reserve ...
Baggish Aaron L - - 2007
The augmentation of myocardial function that accompanies vigorous exercise is dependent upon adequate coronary artery blood flow reserve. Coronary artery pathology may limit coronary blood flow and produce myocardial ischemia. The clinician charged with the care of athletes must have a high index of suspicion for underlying coronary artery pathology ...
Sukmawan Renan - - 2007
We examined whether edaravone (3-methyl-1-phenyl-2-pyrazolin-5-one), a free radical scavenger, exerts its protective effect on coronary microvessels after ischemia/reperfusion (I/R) in vivo. Ninety-minute coronary occlusion followed by reperfusion was performed in 16 open-chest dogs with and without edaravone administration. Coronary small artery (> or = 100 microm in size) and arteriolar ...
Kaufmann Philipp A PA Medical Research Council Clinical Sciences Center, Imperial College, Hammersmith Hospital, London, United - - 2007
We studied the impact of systemic infusion of the nitric oxide synthase (NOS) inhibitor N(G)-monomethyl-L-arginine (L-NMMA) on coronary flow reserve (CFR) in patients with coronary artery disease (CAD). We have previously demonstrated that CFR to adenosine was significantly increased after systemic infusion of L-NMMA in normal volunteers but not in ...
Kasuya, Yoshitoshi
Thesis--University of Tsukuba, D.M.S.(A), no. 804, 1990. 10. 31
Worthley Matthew I - - 2007
OBJECTIVES: Reduced nitric oxide (NO) bioavailability is a key mechanism in the development of endothelial dysfunction. The NO synthase cofactor, tetrahydrobiopterin (BH4), increases NO availability, yet its effect in the human coronary circulation, particularly following PCI, remains uncertain. This study was designed to evaluate the effects of intracoronary BH4 in ...
Melikian Narbeh - - 2007
AIMS: To validate a novel method for assessment of coronary endothelium-dependent microvascular function and compare this index with the adenosine-derived coronary flow reserve (CFR). METHODS AND RESULTS: We validated use of intra-coronary pressure wire-derived thermodilution to assess changes in coronary flow compared to Doppler flow-wire/quantitative coronary angiography- (QCA) derived data ...
Ozdemir Murat - - 2007
OBJECTIVE: Myocardial fractional flow reserve (FFR) is utilized to determine the hemodynamic significance of coronary stenoses. We sought to determine the effect, if any, of metoprolol on FFR in patients with coronary stenoses of intermediate severity. METHODS AND RESULTS: Eighteen patients (10 males, mean age, 59.4 +/- 7.7 years) with ...
Cunha-Goncalves Doris - - 2007
Sepsis-associated myocardial depression is associated with calcium desensitization and adrenergic uncoupling. We conducted a prospective randomized investigation on the effects of the calcium sensitizer, levosimendan, on hemodynamics, myocardial blood flow, and myocardial lactate metabolism during porcine endotoxemia. Twelve pigs were studied. Oxygen consumption was measured by indirect calorimetry, and myocardial ...
Kozlovski Valery I VI Department of Experimental Pharmacology, Chair of Pharmacology, Jagiellonian University Medical College, Grzegórzecka 16, PL 31-531 Kraków, - - 2007
Both angiotensin-converting enzyme (ACE) and neutral endopeptidase (NEP) are involved in the regulation of renin-angiotensin and kallikrein-kinin systems. The aim of the present study was to assess the role of NEPand ACE in the regulation of vascular responses to angiotensin I (Ang I), angiotensin II (Ang II) and bradykinin (Bk) ...
Weigel Guenter - - 2007
OBJECTIVES: Strategies to recover myocardium in therapeutically unresponsive patients are again under scrutiny, including techniques developed in the pioneering days of cardiothoracic surgery such as retroperfusion via the coronary sinus--the Beck procedure. An underestimated aspect of retroperfusion is the formation of new vessels. This early observation of neoangiogenesis may be ...
Hatanaka Kunihiko - - 2007
BACKGROUND: Adenosine has been available for use in myocardial perfusion single-photon emission computed tomography (SPECT) in Japan since 2005. The purpose of this study was to evaluate the safety of and tolerance to thallium-201 myocardial perfusion SPECT with intravenous adenosine infusion in Japanese patients with suspected coronary artery disease. METHODS ...
Knudson Jarrod D - - 2007
The incidence of obesity and the metabolic syndrome has reached epidemic proportions and alterations in coronary microvascular function could contribute to the increased cardiovascular morbidity and mortality observed in these patients. This review highlights key mechanisms of impaired control of coronary blood flow in the metabolic syndrome. Specifically, coronary endothelial ...
Lavi Shahar - - 2007
BACKGROUND: Lipoprotein-associated phospholipase A2 (Lp-PLA2) is a novel marker and participant in vascular inflammation. Inflammation also is associated with coronary atherosclerosis. We tested the hypothesis that local coronary production of Lp-PLA2 is enhanced in patients with early coronary atherosclerosis and associated with local endothelial function. METHODS AND RESULTS: Coronary angiography, ...
Grisk Olaf - - 2007
The metabolic syndrome is associated with an increased risk for coronary heart disease. The underlying mechanisms are not well understood. The present study was designed to investigate coronary function in Wistar Ottawa Karlsburg W (WOKW) rats, a new animal model of the metabolic syndrome. The responses of coronary artery segments ...
Daghini Elena - - 2007
OBJECTIVES: Myocardial microvascular permeability-surface area product (MPSP) and fractional vascular volume (FVV), indices of endothelial function and microvascular perfusion, can be noninvasively evaluated by electron beam computed tomography (EBCT), but it remains unknown whether comparable assessments can be obtained with 64-slice multidetector CT (CT-64). METHODS: We studied 12 pigs with ...
Akhtar Mateen - - 2007
Dipyridamole increases adenosine levels and augments coronary collateralization in patients with coronary ischemia. This pilot study tested whether a 6-month course of sustained-release dipyridamole/aspirin improves coronary flow reserve and left ventricular systolic function in patients with ischemic cardiomyopathy. Six outpatients with coronary artery disease and left ventricular ejection fraction (LVEF) ...
Kokusho Yasunori - - 2007
OBJECTIVE: Coronary flow is closely correlated to the myocardial metabolic demand. We tested the hypothesis that hydrogen peroxide (H2O2) derived from beating hearts mediates metabolic coronary microvascular dilation. METHODS AND RESULTS: We used a bioassay method in which an isolated microvessel is placed on a beating heart to detect myocardium-derived ...
Hirohata Atsushi - - 2007
Cardiac allograft vasculopathy (CAV) is a progressive process involving the epicardial and microvascular coronary systems. The timing of the development of abnormalities in these 2 compartments and the correlation between changes in physiology and anatomy are undefined. The invasive evaluation of coronary artery anatomy and physiology with intravascular ultrasound, fractional ...
McNulty Patrick H - - 2007
Patients with diabetes mellitus exhibit postprandial hyperglycemia, systemic oxidative stress, impaired endothelium-dependent, nitric oxide (NO)-mediated coronary artery dilatation, and an increased incidence of coronary events. Whether hyperglycemia causally mediates these associations is unknown. To test the hypothesis that postprandial hyperglycemia acutely impairs coronary endothelial function in humans, we compared the ...
Halcox Julian P J - - 2007
Endothelin 1 mediates coronary vasoconstriction and endothelial dysfunction via endothelin receptor type A (ET(A)) activation. However, the effects of selective endothelin receptor type B (ET(B)) and combined ET(A+B) receptor blockade on coronary vasomotion are unknown. We measured coronary vascular tone and endothelium-dependent and -independent vasomotor function before and after selective ...
Parikh Keyur H - - 2007
No or slow reflow following percutaneous coronary intervention (PCI), despite the presence of a patent epicardial vessel, is a serious complication resulting in increased morbidity and mortality. In the present study, we have evaluated the combination therapy of adenosine and sodium nitroprusside administered as sequential intracoronary (IC) boluses on no-reflow ...
Gill Robert M - - 2007
In congestive heart failure (CHF), coronary vascular relaxation is associated with endothelial dysfunction and nitric oxide (NO) deficiency. This study explored the reversibility of this process in hearts recovering from CHF and its related mechanisms. Dogs were chronically instrumented to measure cardiac function and coronary blood flow (CBF). Heart failure ...
McNulty Patrick H - - 2007
Pathological formation of reactive oxygen species within the coronary circulation has been hypothesized to mediate some clinical manifestations of ischemic heart disease (IHD) by interfering with physiological regulation of coronary tone. To determine the degree to which coronary tone responds to acute changes in ambient levels of oxidants and antioxidants ...
Olivecrona Goran K - - 2007
BACKGROUND: The endothelial ADP receptor P2Y(1) is responsible for a large part of the reactive hyperemia following cardiac ischemia. Tissue plasminogen activator (t-PA) increases during reactive hyperemia. We postulated that the release of t-PA during reactive hyperemia could be mitigated through blocking the coronary endothelial P2Y(1) receptor. METHODS: t-PA was ...
Tatematsu Satoru - - 2007
Cardiovascular events are accelerated in chronic kidney disease (CKD). Although deranged nitric oxide (NO) pathways and asymmetric dimethylarginine (ADMA) cause endothelial dysfunction, no direct evidence for coronary artery endothelial dysfunction in CKD has been documented. CKD was induced in male dogs by heminephrectomy (1/2Nx) or five-sixths nephrectomy (5/6Nx). After 4 ...
Shimbo Daichi D Behavioral Cardiovascular Health and Hypertension Program, Division of General Medicine, Columbia University Medical Center, New York, New York, USA. - - 2007
Anger is an independent predictor of coronary heart disease events, although the mechanisms for this relation are unclear. The effects of an anger-provoking interview compared with a neutral interview on endothelium-dependent and -independent vasodilation assessed by brachial artery ultrasound were examined in 14 healthy subjects without coronary heart disease risk ...
Ingram David G DG Department of Biomedical Sciences, University of Missouri, Columbia, MO 65211, - - 2007
Current literature suggests that chronic nitric oxide synthase (NOS) inhibition has differential effects on endothelium-dependent dilation (EDD) of conduit arteries vs. arterioles. Therefore, we hypothesized that chronic inhibition of NOS would impair EDD of porcine left anterior descending (LAD) coronary arteries but not coronary arterioles. Thirty-nine female Yucatan miniature swine ...
Tune Johnathan D - - 2007
Coronary vascular resistance is regulated by a variety of factors including arterial pressure, myocardial metabolism, autonomic nervous system as well as arterial O2 tension (hypoxia). Progressive hypoxemia results in graded coronary vasodilation that is significantly more pronounced when arterial O2 tension falls below 40 mmHg. Microvascular studies have demonstrated that ...
Takashima Hiroyuki - - 2007
BACKGROUND: Cigarette smoking is a major risk factor for acute coronary thrombosis. Bradykinin (BK) can induce the release of tissue plasminogen activator (tPA) from the coronary vasculature. The purpose of this study was to investigate whether smoking reduces BK-stimulated tPA release in human coronary circulation. MATERIALS AND METHODS: We examined ...
Tanriverdi Halil - - 2007
BACKGROUND AND OBJECTIVE: Coronary slow-flow (CSF) phenomenon is characterized by delayed opacification of vessels in a normal coronary angiogram, but its etiopathogenesis remains unclear. Plasma homocysteine (Hcy) level can severely disturb vascular endothelial function and may play a role in the pathogenesis of CSF. In our study, endothelial function in ...
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