Search Results
Results 251 - 300 of 1682
< 1 2 3 4 5 6 7 8 9 10 11 >
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 ...
Jacob Matthias - - 2007
BACKGROUND: Shear stress induces coronary dilatation via production of nitric oxide (NO). This should involve the endothelial glycocalyx (EG). A greater effect was expected of albumin versus hydroxyethyl starch (HES) perfusion, because albumin seals coronary leaks more effectively than HES in an EG-dependent way. METHODS: Isolated hearts (guinea pigs) were ...
Grossini Elena - - 2007
The peptide ghrelin has been linked to the atherosclerotic process and coronary artery disease. We planned to study, for the first time, the primary effects of ghrelin on the intact coronary circulation and determine the mechanisms involved. In 24 sodium pentobarbitone-anesthetized pigs, changes in anterior descending coronary blood flow caused ...
Oflaz Huseyin - - 2007
The diagnosis of subclinical hypothyroidism and detection of its effects on cardiovascular system is important. Also, the patients with subclinical hypothyroidism even at the very early stage are at increased risk for developing atherosclerosis. We evaluated coronary microvascular circulation and endothelial dysfunction of epicardial coronary arteries by the measurement of ...
Makker Robina - - 2006
Increased pulmonary vascular resistance can be detrimental to the cardiac output in post-operative cardiac surgical patients. Pulmonary vasodilator therapy by systemic pharmacologic agents is non-selective. Inhaled nitric oxide is a selective pulmonary vasodilator and does not cause systemic hypotension. In this prospective study, 14 adult post-operative cardiac surgical patients with ...
Nishino Masami - - 2006
BACKGROUND: This study was undertaken to investigate whether coronary flow reserve (CFR) using coronary sinus flow (CSF), which can be measured by transesophageal Doppler echocardiography (TEDE), especially when contrast enhanced, is useful in evaluating microvascular dysfunction in patients with diabetes mellitus (DM). METHODS AND RESULTS: CSF recordings using contrast enhanced ...
Montes Félix R - - 2006
BACKGROUND: Levosimendan, an inotropic drug that enhances myocardial contractility through myofilment calcium sensitazion, induces peripheral vasodilation via opening ATP-dependent K(+) channels. It is unknown whether this drug can be used for the treatment of perioperative vasospasm of arterial conduits used for coronary artery bypass grafting. METHODS: We investigated the effects ...
Cogolludo Angel - - 2007
OBJECTIVE: Large conductance Ca(2+)-activated K(+) channels (BKCa) regulate coronary artery tone in vivo, play a key role in blood pressure regulation, and have been suggested as novel potential drug targets in hypertension. Quercetin exerts systemic and coronary vasodilator effects in vitro and reduces blood pressure in several rat models of ...
Bitar Fahed - - 2006
Attenuation of endothelial-dependent coronary vasodilation has been reported in idiopathic dilated cardiomyopathy and anatomically normal coronaries; however, data are insufficient for understanding the incidence and extent of this finding. The response of conductance and resistance coronary arteries to endothelial stimulation with acetylcholine was examined in 25 patients. Coronary blood flow ...
Dick Gregory M - - 2006
Elevated plasma levels of fat-derived signaling molecules are associated with obesity, vascular endothelial dysfunction, and coronary heart disease; however, little is known about their direct coronary vascular effects. Accordingly, we examined mechanisms by which one adipokine, resistin, affects coronary vascular tone and endothelial function. Studies were conducted in anesthetized dogs ...
Micari Antonio - - 2006
OBJECTIVE: We tested the hypothesis that the cyclic variation in ultrasonic myocardial integrated backscatter (IBS) is due to cardiac contraction-induced changes in the number of patent myocardial microvessels. METHODS: We performed experiments in open-chest dogs in which we increased the number of patent myocardial microvessels without changing cardiac contraction. We ...
Saihara Keishi - - 2006
BACKGROUND: The relationship between coronary remodeling, shear stress and endothelial function remains unclear. OBJECTIVE: The present study investigated the effects of mechanical factors on structure and function of epicardial coronary arteries. METHODS: Patients (group 1: %area stenosis<40%, n=55; or group 2: %area stenosis>or=40%, n=17) with a discrete mildly stenotic lesion ...
Aptecar Eduardo - - 2006
BACKGROUND: Coronary vasomotor responses to sympathetic stimulation vary with endothelial-layer integrity or presence of atherosclerosis. Our study objective was to assess the effects of phenylephrine-induced alpha-adrenergic stimulation on coronary vasomotion in heart transplant recipients with and without graft atherosclerosis. METHODS: Intracoronary phenylephrine (alpha(1)-selective agonist) was injected in 6 control subjects, ...
Maas Renke - - 2007
OBJECTIVE: To investigate the association of the endogenous nitric oxide synthase inhibitor asymmetrical dimethylarginine (ADMA) and coronary endothelial function. METHODS AND RESULTS: In 289 patients with coronary artery disease we assessed coronary endothelium-dependent and -independent vascular responses to intracoronary infusion of acetylcholine, adenosine, and nitroglycerin, respectively, and determined plasma ADMA ...
Prakash Rajan - - 2006
OBJECTIVE: To test the hypothesis that vasomotor control is impaired in the coronary circulation of prediabetic obese (OZR) relative to lean Zucker rats (LZR). METHODS: Cardiac function was assessed with in vivo measures of cardiac output and microvascular structure and function was assessed in vitro using videomicroscopic techniques. RESULTS: OZR ...
Merkus Daphne - - 2006
The renin-angiotensin system plays an important role in cardiovascular homeostasis by contributing to the regulation of blood volume, blood pressure, and vascular tone. Because AT(1) receptors have been described in the coronary microcirculation, we investigated whether ANG II contributes to the regulation of coronary vascular tone and whether its contribution ...
Koifman Bella - - 2006
The purpose of the present study was to evaluate the effects of losartan and the combination of losartan and L-arginine on endothelial function and hemodynamic variables in patients with heart failure (HF). Endothelium-dependent vasodilation is impaired in patients with HF. It was hypothesized that the administration of losartan and the ...
Tanriverdi Halil - - 2006
BACKGROUND AND OBJECTIVE: Coronary slow-flow phenomenon is characterized by delayed opacification of coronary vessels in a normal coronary angiogram. Although clinical and pathological features have been previously described, the underlying pathophysiology has not been fully elucidated. Thus, it still remains to be determined whether either microvascular or epicardial diffuse atherosclerotic ...
Tanriverdi Halil - - 2006
BACKGROUND: Smoking contributes to the progression of atherosclerotic heart disease by causing endothelial dysfunction. In the present study the effect of smoking on endothelial functions and coronary flow was investigated, as well as the relationship of these factors with oxidative stress parameters, in subjects with normal coronary arteries. MATERIALS AND ...
< 1 2 3 4 5 6 7 8 9 10 11 >