Search results for "coronary circulation"

Stable microvascular angina: instrumental evaluation of coronary microvascular dysfunction with coronary angiography and myocardial scintigraphy

2014

Methods to investigate coronary microvascular function in clinical practice.

2012

A growing amount of data is increasingly showing the relevance of coronary microvascular dysfunction (CMVD) in several clinical contexts. This article reviews techniques and clinical investigations of the main noninvasive and invasive methods proposed to study coronary microcirculation and to identify CMVD in the presence of normal coronary arteries, also trying to provide indications for their application in clinical practice.

Quantification of resting myocardial blood flow in a pig model of acute ischemia based on first-pass MRI

2005

Qualitative and semiquantitative contrast-enhanced (CE) dynamic perfusion MRI techniques are established as noninvasive diagnostic means of assessing coronary artery disease. However, to date quantification of myocardial blood flow (MBF) has not reached the same acceptance as MBF quantification with nuclear techniques. To validate quantification of MBF at rest using the extracellular contrast agent (CA) Gd-DTPA, we performed an animal study in a pig model of acute myocardial ischemia. We quantified MBF from MRI data with a mathematical model (MMID4) of the underlying vasculature. These MBF results were subsequently compared with the results from fluorescent microspheres. The study showed a …

Protective role of the complement regulatory protein human CD-55 in cardiac xenograft: a descriptive study and a revision of the literature.

2002

The limited and inadequate availability of organs from human donors has resulted in the utilisation of xenografts as an alternative tool. Nevertheless, hyperacute rejection (HAR) following xenograft determines the loss of the transplanted organ. The “primum movens” is the activation of the complement pathway mediated by the binding of natural xenogenic antibodies to the endothelium of the graft, followed by the lysis of the endothelial cells with subsequent oedema, thrombosis and necrosis of the transplanted organ. In this work we describe morphological and biomolecular observations of isolated human-decay accelerating factor (h-DAF, CD55) transgenic pig hearts, after perfusion for four hou…

Dissociation of theophylline uptake and inotropic effect in myocardial tissue: influence of temperature, pH and calcium.

1975

1. The myocardial uptake and the positive inotropic effect of theophylline (100 mug/ml; 0.56 mM) were studied in isolated electrically driven guinea-pig hearts perfused by the Langendorff technique under various extracellular conditions. [3H]-theophylline was used. 2. Variations in temperature, hydrogen ion and calcium ion concentrations of the perfusion media changed the time course and magnitude of the effect of theophylline on myocardial twitch tension but did not affect the time course and amount of theophylline uptake. 3. Under all conditions, the build-up of the positive inotropic effect of theophylline was about three times faster than the uptake of the drug into the heart. 4. Since …

Chronic Administration of Quercetin Induces Biomechanical and Pharmacological Remodeling in the Rat Coronary Arteries

2017

Acute dilation brought about by the dietary flavonoid quercetin in coronary arterioles has been described earlier, but no information is available on its chronic effects. Male Wistar rats (body weight about 190 g) were divided to two groups: the quercetin-treated group (n=22) had quercetin supplementation of approximately 30 mg/kg/day, whereas the control group (n=20) had none. After eight weeks of treatment, intramural coronary arterioles with identical passive diameters (178+/-14 microm and 171+/-9 microm) were prepared and their biomechanics and pharmacological reactivities were tested using pressure arteriography ex vivo. The spontaneous tone of quercetin-treated arteries was higher (16…

Takotsubo Cardiomyopathy: One More Angiographic Evidence of Microvascular Dysfunction

2017

Background Takotsubo cardiomyopathy (TC) aetiology has not been completely understood yet. One proposed pathogenic mechanism was coronary microvascular dysfunction (MVD). This study compared coronary flow and myocardial perfusion in patients with TC, microvascular angina (MVA), and a control group (CG). Methods Out of 42 consecutive patients presented to our centre with TC from 2013 to 2017; we retrospectively selected 27 patients. We compared them with a sex- and age-matched group of 27 MVA cases and 27 patients with normal coronary arteries (CG). The flow was evaluated in the three coronary arteries as TIMI flow and TIMI frame count (TFC). Myocardial perfusion was studied with Blush-Score…

Limitations of Myocardial Blush Grade in the Evaluation of Myocardial Perfusion in Patients With Acute Myocardial Infarction and TIMI Grade 3 Flow

2006

Introduction and objectives An analysis was made of variability in the measurement of the angiographic index blush between a university hospital and an independent core laboratory, as well as its correlation with perfusion analised by intracoronary myocardial contrast echocardigraphy (MCE) and the ventricular function at the sixth month. Methods The study comprised 40 patients with a first ST-segment elevation myocardial infarction, single-vessel disease and open infarct-related artery. Perfusion was quantified by angiography (median fifth day, range 3-7) with blush in our laboratory and in an independent core laboratory. MCE was performed. Ejection fraction at the sixth month was determine…

Acute Administration of Epirubicin Induces Myocardial Depression in Isolated Rat Heart and Production of Radical Species Evaluated by Electron Spin R…

2007

The aim of our study was to evaluate the acute effect of epirubicin (EPI), an anthracycline anticancer drug, on the evolution of cardiac functional parameters and production of reactive oxygen/nitrogen species (RONS). Isolated perfused rat hearts were subjected to 70 minutes of EPI (10.3 microM) infusion and to 5 minutes of isoproterenol (ISO, 0.1 microM) at the end of the protocol. Coronary flow (CF), left ventricular developed pressure (LVDP), and lactate dehydrogenase (LDH) release in the coronary effluents were evaluated throughout the protocol. RONS were detected in the coronary effluents by electron spin resonance spectroscopy with a spin probe, 1-hydroxy-3-carboxy-pyrrolidine (CP-H, …

Acute in vivo administration of a fish oil-containing emulsion improves post-ischemic cardiac function in n-3-depleted rats

2006

International audience; A novel i.v. lipid preparation (MCT:FO) containing 80% medium chain-triacylglycerols and 20% fish oil was recently developed to rapidly replenish cell membrane phospholipids with omega 3 (n-3) polyunsaturated fatty acids (PUFA). In regard of this property, we investigated the effect of a single i.v. administration of MCT:FO on the recovery of cardiac function after ischemia in control and n-3-depleted rats. Results were compared with those obtained either with a control preparation, where FO was replaced by triolein (MCT:OO), or with saline. Saline (1 ml) or lipid preparation (also 1 ml) was injected as a bolus via the left saphenous vein. After 60 min the heart was …