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Schindler Thomas H - - 2009
PURPOSE: To determine the relationship between carotid intima-media thickness (IMT), coronary artery calcification (CAC), and myocardial blood flow (MBF) at rest and during vasomotor stress in type 2 diabetes mellitus (DM). METHODS: In 68 individuals, carotid IMT was measured using high-resolution vascular ultrasound, while the presence of CAC was determined ...
Yildiz Ali - - 2008
OBJECTIVES: To investigate the association between elasticity indexes of aorta and severity of coronary artery disease (CAD) in patients with stable CAD. METHODS: Fifty-six patients with CAD (CAD group) and 40 patients without CAD [non CAD (NCAD group)] were included in the study. Ascending aorta (Ao) diameters (mm) and Ao ...
Pletcher Mark J - - 2008
High blood pressure in middle age is a well-established risk factor for cardiovascular disease, but the consequences of low-level elevations during young adulthood are unknown. To measure the association between prehypertension exposure before age 35 years and coronary calcium later in life. Prospective cohort study. Four communities in the United ...
Skyschally Andreas - - 2008
AIMS: We addressed calcium responsiveness in microembolized myocardium at 6 h after coronary microembolization (ME). METHODS AND RESULTS: In anesthetized pigs calcium responsiveness was determined as the increase of a myocardial work index (WI; LV pressure development vs. wall thickening) in response to a graded intracoronary infusion of CaCl(2) at ...
Jameel Mohammad N MN Cardiovascular Division, Departments of Medicine, University of Minnesota Medical School. Minneapolis, Minnesota, - - 2008
The heterogeneity across the left ventricular wall is characterized by higher rates of oxygen consumption, systolic thickening fraction, myocardial perfusion, and lower energetic state in the subendocardial layers (ENDO). During dobutamine stimulation-induced demand ischemia, the transmural distribution of energy demand and metabolic markers of ischemia are not known. In this ...
Ahmari Saeed A L - - 2008
Traditional cardiovascular risk factors have been shown to cause microvascular dysfunction. Most studies that have evaluated microcirculation rely on invasive measurement tools. We used dobutamine stress echocardiography, a validated method to measure coronary flow velocity (CFV) and coronary flow reserve (CFR), in a previously unstudied population without known significant coronary ...
Tayyareci Yelda - - 2008
This study investigated the effects of intracoronary autologous bone marrow-derived mononuclear cell (BMC) transplantation on coronary microcirculation. Fifteen patients with ischemic cardiomyopathy were treated by intracoronary infusion of BMCs via the patent infarct-related artery. The thermodilution-derived coronary flow reserve, index of microvascular resistance, pressure-derived collateral flow index, and coronary wedge ...
Tverskaya M S - - 2008
Comparative study of pathomorphology of myocardial circulation under conditions of increased afterload of the left or right ventricles showed similar changes. All compartments of the coronary bed were plethoric, capillary blood stasis and perivascular edema, more pronounced in arterial vessels, were detected in both cases. These changes equally involved both ...
McGeoch Ross J RJ Department of Cardiology, Western Infirmary, Glasgow, United Kingdom. - - 2008
The coronary pressure wire is used for physiological assessment of the coronary vasculature increasingly frequently in clinical practice. Fractional flow reserve (FFR) can now be used to assess lesion severity in a variety of anatomical situations. Increasingly, the coronary pressure wire is being used to interrogate the coronary microvasculature. Coronary ...
Leithäuser B - - 2008
Xantinole nicotinic acid (NA) dose dependently lowers plasma levels of atherogenic lipoproteins and increases blood flow through vasodilation. The aim of this study was to evaluate the effect of NA on cutaneous microcirculation in patients with coronary artery disease and hyperlipidemia. In this open pilot study, five men and three ...
Banerjee Rupak K - - 2008
The severity of epicardial coronary stenosis can be assessed by invasive measurements of trans-stenotic pressure drop and flow. A pressure or flow sensor-tipped guidewire inserted across the coronary stenosis causes an overestimation in true trans-stenotic pressure drop and reduction in coronary flow. This may mask the true severity of coronary ...
Rajská P - - 2007
The speed with which horseflies (Diptera: Tabanidae) obtain a bloodmeal suggests they have potent vasodilators. We used isolated perfused rat heart to examine the vasoactivity of salivary gland extracts (SGEs) of three horsefly species, Hybomitra bimaculata Macquart, Tabanus bromius Linnaeus and Tabanus glaucopis Meigen. Administration of horsefly SGEs to the ...
Sinha Roy Abhijit - - 2008
BACKGROUND: Functional/physiological evaluation of coronary artery stenoses may be more important than anatomical measurements of severity. Optimization of thresholds for stenosis intervention and treatment endpoints depend on coupling functional hemodynamic and anatomical data. We sought to develop a single prognostic parameter correlating stenosis-specific anatomy, pressure gradient, and velocities that could ...
Baycan Semra - - 2007
OBJECTIVE: Although the cardiovascular system is highly sensitive to thyroid hormones, the cardiovascular effects of subtle thyroid dysfunction such as subclinical hypothyroidism (SHT) remain unclear. Therefore, we investigated coronary flow reserve (CFR) reflecting coronary microvascular function in patients with SHT. METHODS: Fifty subjects with SHT and 30 control subjects with ...
Yoshitani Hidetoshi - - 2007
BACKGROUND: The benefits of intra-aortic balloon pumping (IABP) usage reportedly occur through systolic unloading of the left ventricle and the augmentation of diastolic coronary flow. The aim of this study was to assess the change in intracoronary pressure distal to the coronary stenosis after the IABP by using an intracoronary ...
Klabunde R E - - 2007
AIM: The purpose of this study was to evaluate the hypothesis that acute hyperglycaemia in hearts of rats without diabetes alters coronary vascular responses to nitric oxide (NO), adenosine (ADO) and phenylephrine (PHE). METHODS: Coronary function was studied in isolated, Langendorff-perfused, non-beating rat hearts that were perfused with an oxygenated ...
Shiina Yumi - - 2008
PURPOSE: It has been reported that mental stress is an independent risk factor for cardiovascular events and impairs coronary circulation. Lavender aromatherapy, one of the most popular complementary treatments, is recognized as a beneficial mental relaxation therapy. However, no study has examined the effect of this therapy on coronary circulation. ...
van't Veer Marcel - - 2007
Orientation of a bi-leaflet prosthesis (BLP) might influence coronary perfusion. The aim of this study was to investigate the influence of the orientation on coronary perfusion pressure during hyperemia and adrenergic stimulation. During hyperemia perfusion pressure determines coronary blood flow. Fourteen patients with normal coronary angiogram underwent aortic valve replacement ...
Suzuki Kazuhito - - 2007
Objective evaluation of the functional significance of individual stenosis in patients with multiple lesions is crucial when performing percutaneous coronary intervention (PCI). Here we propose a novel lesion-specific parameter, the epicardial resistance index (ERI), which is derived from intracoronary pressure measurements, and validate its clinical usefulness. The ERI is defined ...
Hodgson John McB - - 2007
The purpose of this study was to define binodenoson dosing regimens that produce coronary hyperemia comparable to those of adenosine and that are tolerated well by patients. An open-label, randomized, parallel-group, multicenter study enrolled adult patients who had completed diagnostic cardiac catheterization. Coronary blood flow velocity (CBFV) was measured with ...
Van Herck P L - - 2007
To investigate the underlying mechanisms of a decreased coronary flow reserve after myocardial infarction (MI) by analysing the characteristics of the diastolic hyperaemic coronary pressure-flow relationship. Prospective study. Tertiary care hospital. 68 patients with a recent MI and 27 patients with stable angina pectoris (AP; control group). The intercept with ...
Malester Brian - - 2007
K(ATP) channels are involved in regulating coronary function, but the contribution of endothelial K(ATP) channels remains largely uncharacterized. We generated a transgenic mouse model to specifically target endothelial K(ATP) channels by expressing a dominant negative Kir6.1 subunit only in the endothelium. These animals had no obvious overt phenotype and no ...
Schega Lutz - - 2007
PURPOSE: Water is frequently recommended as a therapeutic medium for cardiac patients. Reports on the cardiovascular response to immersion often differ, however, depending, for instance, if full or partial immersion were considered. The purpose of this study was to examine the cardiovascular responses to 2 immersion protocols in 3 age ...
Cheng Eric M EM Department of Neurology, VA Greater Los Angeles Healthcare System, Los Angeles, CA 90073, USA. - - 2007
Undergoing a carotid endarterectomy, a coronary artery bypass graft, or a percutaneous coronary intervention provides an opportunity to optimize control of blood pressure and low-density lipoprotein. Using Veterans Administration databases, we determined whether patients who underwent a carotid endarterectomy (n=252), coronary artery bypass graft (n=486), or percutaneous coronary intervention (n=720) ...
Verberne Hein J - - 2007
The aim of this study was to assess the influence of a second guidewire on the diagnostic accuracy of functional parameters of coronary lesion severity. Sixty-five patients with intermediate coronary lesions underwent myocardial perfusion scintigraphy. Fractional flow reserve (FFR), coronary flow velocity reserve (CFVR), and hyperemic stenosis resistance (HSR) index ...
Torii Ryo - - 2007
Catheter-delivered intravascular probes are widely used in clinical practice to measure coronary arterial velocity and pressure, but the artefactual effect of the probe on the variables being measured is not well characterised. A coronary artery was simulated with a 180 degrees curved tube 3mm in diameter and the effect of ...
Lyras Theodore - - 2007
OBJECTIVE: Attempts to demonstrate preconditioning during repeated angioplasty balloon inflations (BIs) have not been universally successful. The main obstacle is that the first BI is unreliable, due to the variable degrees of occlusion by the deflated balloon. In the present study, we examined whether ST segment elevation decreases and evaluated ...
Salvadori Claudia - - 2007
A 72-year-old woman was admitted to our hospital for chest pain and dyspnea. Admission electrocardiogram revealed T-wave inversion in precordial leads. Coronary angiography showed no significant coronary artery disease. Left ventriculography showed apical akinesis and basal hyperkinesis with an intraventricular pressure gradient of 60 mmHg. After 4 days left ventricular ...
Erdogan Dogan - - 2007
BACKGROUND: Impaired coronary flow reserve (CFR) is a significant predictor of poor prognosis in patients with idiopathic dilated cardiomyopathy (IDC). Nebivolol reduces mortality and morbidity in patients with heart failure and left ventricular dysfunction, including cases caused by IDC. OBJECTIVE: To assess the effects of nebivolol on CFR in patients ...
Bovendeerd Peter H M - - 2006
The phasic coronary arterial inflow during the normal cardiac cycle has been explained with simple (waterfall, intramyocardial pump) models, emphasizing the role of ventricular pressure. To explain changes in isovolumic and low afterload beats, these models were extended with the effect of three-dimensional wall stress, nonlinear characteristics of the coronary ...
Saihara Keishi - - 2006
Effects of cibenzoline on coronary hemodynamics, especially systolic reversal flow, were assessed in a 53-year-old man with hypertrophic obstructive cardiomyopathy by coronary flow study using a Doppler guidewire. Intravenous administration of cibenzoline resulted in decreases in the pressure gradient (60 to 0mmHg) and systolic left ventricular pressure (162 to 126 ...
Kostelec Monica - - 2006
OBJECTIVE: Heart failure was induced by cardiac pacing to evaluate myocardial flow distribution of the open ventricle during delivery of either cardioplegia or in the beating state during simulated left ventricular restoration. METHODS: Studies included 5 (pacing-induced) failing pig hearts and 6 control hearts. Pacing-induced cardiac failure reduced fractional shortening ...
Pascotto Marco - - 2007
The systolic to diastolic arteriolar blood volume (aBV) ratio derived using myocardial contrast echocardiography (MCE) can identify the presence of coronary stenosis at rest. There are some patients with moderate to severe coronary stenosis who nonetheless exhibit a normal systolic to disatolic aBV ratio. To test the hypothesis that collateral ...
Hamilton Garun S - - 2006
BACKGROUND AND PURPOSE: Much remains unknown about the regulation of coronary artery blood flow (CBF), particularly during sleep and sleep-related disease states such as obstructive sleep apnoea (OSA). Mediators produced by the endothelium are known to be crucial in the regulation of CBF, particularly vasodilator substances such as nitric oxide. ...
Vavuranakis Manolis - - 2007
OBJECTIVES: We sought to investigate the differences of pressure waveforms at a distal point of an epicardial coronary artery comparatively to the ostium and to assess the effect of microcirculatory vasodilation on them. BACKGROUND: Pressure waveforms in the systematic circulation and their alterations along the aorta due to wave reflections ...
Prior John O - - 2007
PURPOSE: Response of myocardial blood flow (MBF) to sympathetic stimulation with cold is modulated by endothelium-related factors and is typically altered in the presence of coronary risk factors. Determinants of flow response to cold pressor testing (CPT) in normal volunteers at low risk for CAD remain less well defined, especially ...
Fernández N - - 2006
To study the effects of arterial pressure on coronary reactive hyperaemia, left circumflex coronary artery flow was measured, and reactive hyperaemia was determined after 5, 10 or 20 s of occlusion of this artery in anaesthetized goats during normotension, hypertension and hypotension. During hypertension induced by aortic constriction (mean arterial ...
Knobloch Karsten - - 2006
BACKGROUND: The aim of this study was to assess palmar microcirculation in a long-term follow-up after radial artery harvesting for coronary revascularization. METHODS: One hundred fourteen patients (100 male; aged 61.7 +/- 6.7 years; preoperative New York Heart Association 2.3 +/- 0.6, ejection fraction 61.4% +/- 13.9%) were included after ...
Schindler Thomas H - - 2006
PURPOSE: We investigated whether a myocardial perfusion gradient during pharmacologically induced hyperemia also occurred during sympathetic stimulation with cold pressor testing (CPT), which commonly induces a paradoxical coronary vasoconstriction in individuals with coronary risk factors. METHODS: Myocardial blood flow (MBF) was measured in absolute units (ml/g/min) with 13N-ammonia and PET ...
Ng Martin K C - - 2006
BACKGROUND: A simple, reproducible invasive method for assessing the coronary microcirculation is lacking. A novel index of microcirculatory resistance (IMR) has been shown in animals to correlate with true microvascular resistance and, unlike coronary flow reserve (CFR), to be independent of the epicardial artery. We sought to compare the reproducibility ...
Jagathesan R R MRC Clinical Sciences Centre, Imperial College, London, - - 2006
To compare the relationship between dobutamine myocardial blood flow (MBF), rate-pressure product (RPP) and stenosis severity in patients with coronary artery disease (CAD). 27 patients with single-vessel CAD were allocated to three groups based on stenosis severity: group 1, 50-69% (n = 9); group 2, 70-89% (n = 9); and ...
Cerillo Alfredogiuseppe - - 2006
Retrograde cardioplegia (RC) delivery may result in suboptimal myocardial protection, due to leakage of cardioplegia to the right atrium. This study was undertaken to assess the efficacy of a double balloon cannula (DBC) occluding the coronary sinus ostium during RC. Fifteen patients were randomly assigned to receive RC via a ...
Kazmaier S - - 2006
OBJECTIVE: The objective of this study was to describe the diastolic pressure-flow relationship and to assess critical occlusion pressure in arterial coronary bypass grafts in human beings. METHODS AND RESULTS: Fifteen patients were studied following elective surgical coronary artery bypass grafting. Flow in the left internal mammary artery bypass to ...
Spaan Jos A E - - 2006
In deriving clinically used hemodynamic indices such as fractional flow reserve and coronary flow velocity reserve, simplified models of the coronary circulation are used. In particular, myocardial resistance is assumed to be independent of factors such as heart contraction and driving pressure. These simplifying assumptions are not always justified. In ...
Bi Xiaoming - - 2006
In this study, coronary MRA was performed on 10 healthy volunteers using the whole-heart and volume-targeted scans with comparable imaging parameters. Similar results in the SNR, CNR, and vessel diameter were observed. The depicted length of coronary arteries was longer using the whole-heart scan (whole-heart: RCA/LAD = 13.4 +/- 3.9/10.5 ...
Sinha Roy Abhijit - - 2006
To evaluate the local hemodynamic effects of coronary artery balloon angioplasty, computational fluid dynamics was applied to representative stenoses geometry post-angioplasty (minimal lesion diameter d(m) = 1.8mm which produced 64% mean area stenoses) based on a group of patients and measured values of coronary flow reserve (CFR) returning to a ...
Choy Jenny Susana - - 2006
The pressure-induced remodeling of coronary veins is important in coronary venous retroperfusion. Our hypothesis is that the response of the large coronary veins to pressure overload will depend on the degree of myocardial support. Eleven normal Yorkshire swine from either sex, weighing 31-39 kg, were studied. Five pigs underwent ligation ...
Navia Jose L - - 2005
Myocardial salvage through coronary sinus intervention has been documented. The AutoRetroPerfusion Cannula is a novel device that is able to perfuse the coronary bed retrogradely through the coronary sinus with arterial blood generated from a peripheral artery with no need for a pump. The cannula consists of a distal end ...
Azzawi May - - 2006
The aims of the study were to investigate whether elevated extravascular pressure modulates responses of isolated rat coronary arteries to constrictor and dilator stimuli. Isolated segments of rat coronary artery were mounted in a modified pressure myograph system that allowed independent modulation of both intra- and extravascular pressures. The influence ...
Vogel Rolf - - 2006
AIMS: Myocardial blood flow (MBF) is the gold standard to assess myocardial blood supply and, as recently shown, can be obtained by myocardial contrast echocardiography (MCE). The aims of this human study are (i) to test whether measurements of collateral-derived MBF by MCE are feasible during elective angioplasty and (ii) ...
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