Search results for "Artery"
showing 10 items of 2026 documents
THE ROLE OF INFLAMMATION IN TYPE A AORTIC DISSECTION: A PILOT STUDY
2013
Type A aortic dissection (TAAD) is a severe cardiovascular disease with high mortality rates. Current evidence suggests inflammation as the main mechanism of its complex pathophysiology. Accordingly, in this study the eventual presence of inflammatory cells in aorta specimens and any contribution of these cells in both apoptosis and metalloproteinase levels were assessed. The potential relationship between plasma inflammatory molecules and TAAD was also detected. In addition, implication in TAAD susceptibility of ten common and functional single nucleotide polymorphisms (SNP)s of six candidate genes (CCR5, TLR4, ACE, eNOs, MMP-9 and −2) was determined. Thus, histo-pathological and immunois…
Diameter Control in the Arteriolar Tree by Changes in Post-Capillary Resistance
1997
Presently, the mechanisms underlying local adjustment of organ perfusion to the metabolic needs of the tissue are not well understood. Even though a large number of vasoactive substances is known to be released upon variations in tissue metabolism,24,28 the exact mechanisms of their action are unclear: Because diffusion is a slow and inefficient transport process for covering long distances, arterioles can only sense those changes in concentration and hence in release rate of these mediators with acceptable spatial and temporal resolution that originate from their immediate vicinity. On the other hand, perfusion needs to be regulated such that also the worst supplied tissue regions located …
The automated assesment of artery hemodynamic parameters from ultrasound video
2012
The custom designed video processing software for analysis of B-mode and Doppler-mode ultrasound video has been proposed in this work. The software allows adjusting user-defined thresholds and tolerance levels to enhance contour detection in noisy and artifacted ultrasound images. The developed software is able to evaluate 16 hemodynamic parameters (artery diameter, pulse rate and flow velocity related parameters) in each cardiac cycle. The measurements were performed intermittently recording artery diameter (B-mode) and flow velocity (Doppler-mode). Software has validated in femoral artery measurements. The hemodynamic parameters computed by software were consistent with those obtained by …
Epicardial Fat, Cardiac Geometry and Cardiac Function in Patients with Nonalcoholic Fatty Liver Disease: Association with the Severity of Liver Disea…
2015
Background & Aims Non-alcoholic fatty liver disease (NAFLD) has been associated with increased cardiovascular risk, including coronary artery disease and cardiac dysfunction. In addition, recent evidence highlighted the possible role of epicardial fat as a new cardiometabolic risk factor. We tested the correlation between epicardial fat, alterations in cardiac geometry and function, and severity of liver damage, in patients with biopsy-proven NAFLD. Methods The anthropometric, biochemical and metabolic features were recorded in 147 consecutive biopsy-proven NAFLD cases (Kleiner score). Epicardial fat thickness was measured by echocardiography. Results Epicardial fat was higher in patients w…
Impact of high-fat diet on antioxidant status, vascular wall thickening and cardiac function in adult female LDLR<sup>–/–</sup> mice
2012
International audience; Background: Western diet, rich in saturated fatty acids and cholesterol, is associated with increased cardiovascular risk. We thus investigated in female mice the influence of this diet on plasma antioxidant status, vascular wall thickening and cardiac function. Methods and Results: Adult female C57BL/6J wild type (WT) and LDLR–/– mice were fed a normal diet (ND) or a high-fat diet (HFD) for 17 weeks. HFD induced an increase in plasma lipids and vitamin C (Vit C) levels in both groups but at a much higher level in LDLR–/– and a decrease in plasma ascorbyl free radical levels to Vit C ratio (an endogenous oxidative stress index) in LDLR–/–. We only found a slight decr…
Systematische Analyse der Geometrie eines definierten Kontrastmittelbolus - Implikationen für die kontrastmittelverstärkte 3D-MR-Angiographie thoraka…
2005
Purpose: Little is known about the dispersion of a defined contrast bolus during its passage through the heart and pulmonary vasculature. The purpose of this study was to analyze factors influencing a defined contrast bolus for ce-MRA of thoracic vessels. Materials and Methods: For analysis of bolus geometry, an ECG-gated saturation-recovery Turbo-Flash sequence with a TI of 20 msec was used. It was acquired axially at the level of the pulmonary trunc, so that with one data acquisition a curve analysis was possible in the ascending and descending aorta, and in the pulmonary trunc. Twenty-nine patients received 3 ml of Gd-DTPA diluted with saline to a total of 20 ml. Contrast injection was d…
Hämodynamik nach sublingualer Applikation von Captopril bei schwerer Herzinsuffizienz*: Eine Pilotstudie
2008
In a preliminary trial, 23 patients in severe left-heart failure and, in some instances, also right-heart failure (NYHA classes III and IV) received a single sublingual dose of 25 mg captopril. Invasive measurement of various haemodynamic parameters indicated (1) an increase in cardiac index and stroke-volume index of 34% and 38%, respectively (P less than 0.001 for each); (2) decrease in pulmonary artery and systemic pressures by an average of 7% and 11.4% (P less than 0.01 and less than 0.001, respectively); (3) no significant change in heart rate and mean right atrial pressure; (4) decrease in systemic and pulmonary artery resistance by 33% and 29% (P less than 0.001 for both); (5) an in…
[Coronary microvascular dysfunction: past, present, and future of an evolving disease].
2017
Coronary atherosclerosis is the main cause of myocardial ischemia. Nevertheless 10-30% of patients with angina has angiographically normal coronary arteries. In the last 30 years, several studies showed that in these patients the symptoms can be caused by dysfunction of the coronary microcirculation. Coronary microvascular dysfunction (CMVD) occurring in patients affected by specific cardiac or systemic diseases may be due to mechanisms of the underlying disease. On the other hand, in several patients affected by angina with angiographically normal coronary arteries, there is no specific disease, and CMVD only is responsible for the clinical picture. This condition can be defined as leading…
Pulmonary haemodynamics in obstructive sleep apnoea.
1995
In patients with obstructive sleep apnoea syndrome (OSAS), pulmonary haemodynamics can show both transient perturbations during sleep and permanent alterations. During sleep, repeated fluctuations in pulmonary artery pressure and pulmonary wedge pressure, coincident with apnoeas, can be observed. Calculation of transmural pressure values is preferable to intravascular pressures in OSAS, due to the marked swings in intrathoracic pressure associated with obstructive apnoeas. Pulmonary artery pressure may progressively increase during sleep, particularly in close sequences of highly desaturating apnoeas. Apnoea-induced hypoxia appears as the most important determinant of this pulmonary artery …
Cardiac output following fetoscopic coagulation of major placental vessels in fetal sheep.
2008
Objectives To measure changes in cardiac output (CO) after partial cord occlusion in fetal sheep in order to investigate pathophysiological fetal adaptation mechanisms in a simulated acute placental insufficiency model under standardized conditions, with the aim of finding relevant methods for monitoring human fetuses during stress situations. Methods We used minimally invasive, percutaneous endoscopic techniques to close umbilical vessels in mid-gestational fetal sheep. Placental blood flow was reduced by preferentially closing first arterial and then the concomitant venous umbilical vessels within a short time interval. The investigations were carried out on 11 pregnant ewes at a median g…