Search results for "doppler"
showing 10 items of 637 documents
Echocardiographic reference ranges for normal cardiac Doppler data: results from the NORRE Study
2015
International audience; AIMS: Reference values for Doppler parameters according to age and gender are recommended for the assessment of heart physiology, specifically for left ventricular (LV) diastolic function. In this study, we report normal reference ranges for Doppler parameters obtained in a large group of healthy volunteers. Echocardiographic data were acquired using state-of-the-art cardiac ultrasound equipment following Doppler acquisition and measurement protocols approved by the European Association of Cardiovascular Imaging. METHODS AND RESULTS: A total of 449 (mean age: 45.8 ± 13.7 years) healthy volunteers (198 men and 251 women) were enrolled at the collaborating institutions…
Carotid artery stenting with contralateral carotid occlusion in a rare aortic arch configuration
2010
We present the case of a 47-year-old man admitted to our department with an episode of aphasia. Duplex scan showed an occluded right internal carotid artery and severe left internal carotid artery stenosis. Contrast-enhanced computer tomography demonstrated a common trunk for both common carotid arteries anterior to the trachea and aberrant right subclavian artery posterior to the esophagus. The patient was considered to be a high risk for carotid endarterectomy and, consequently, we performed stenting of the left carotid artery. To our knowledge, this is the first case reporting the combination of these two aortic arch anomalies and the concomitant endovascular treatment of atherosclerotic…
Nitric oxide modulates cerebral blood flow stimulation by acetazolamide in the rat cortex: a laser Doppler scanning study
2001
Abstract The involvement of nitric oxide (NO) in cerebral blood flow (CBF) stimulation by acetazolamide was studied in anaesthetised, mechanically ventilated Wistar rats. CBF was monitored by laser Doppler scanning. Acetazolamide induced a long-lasting significant rCBF-increase. Application of N G -Nitro- l -arginine (L-NNA), an inhibitor of all NO synthetases (NOS), prevented CBF stimulation by acetazolamide. Continuous infusion of the exogenous NO donor SIN-1 (3-morpholinosydnonimine) suppressed L-NNA induced increases of mean arterial blood pressure without effect on rCBF in comparison to baseline. Additional acetazolamide injection then again caused a significant increase of rCBF in spi…
Nifedipine improves blood flow and oxygen supply, but not steady-state oxygenation of tumours in perfusion pressure-controlled isolated limb perfusio…
2002
Isolated limb perfusion allows the direct application of therapeutic agents to a tumour-bearing extremity. The present study investigated whether the dihydropyridine-type Ca2+-channel blocker nifedipine could improve blood flow and oxygenation status of experimental tumours during isolated limb perfusion. Perfusion was performed by cannulation of the femoral artery and vein in rats bearing DS-sarcoma on the hind foot dorsum. Perfusion rate was adjusted to maintain a perfusion pressure of 100–140 mmHg throughout the experiment. Following equilibration, nifedipine was continuously infused for 30 min (8.3 μg min−1 kg−1 BW). During constant-pressure isolated limb perfusion, nifedipine can signi…
Localized hypothermia: impact on oxygenation, microregional perfusion, metabolic and bioenergetic status of subcutaneous rat tumours.
1998
The effect of localized hypothermia on microcirculatory and metabolic parameters in s.c. DS sarcomas on the hind foot dorsum of Sprague-Dawley rats was investigated. Tumours were cooled by superfusion of the tumour surface with cooled saline solution to 25 degrees C or 15 degrees C. Control tumours remained at 35 degrees C. These temperatures were maintained for 30 min. In tumour oxygenation measurements, hypothermia at 25 degrees C and 15 degrees C caused progressive decreases in the size of the fraction of pO2 measurements between 0 and 2.5 mmHg together with a reduction in pO2 variability. No significant changes in median or mean pO2 or in the fraction of pO2 measurements between 0 and 5…
Diastolic left ventricular function in relation to circulating metabolic biomarkers in a population study
2019
AimsWe studied the association of circulating metabolic biomarkers with asymptomatic left ventricular diastolic dysfunction, a risk-carrying condition that affects 25% of the population.Methods and resultsIn 570 randomly recruited people, we assessed in 2005–2010 and in 2009–2013 the multivariable-adjusted correlations of e’ (early left ventricular relaxation) and E/e’ (left ventricular filling pressure) measured by Doppler echocardiography with 43 serum metabolites, quantified by magnetic resonance spectroscopy. In 2009–2013, e’ cross-sectionally increased (Bonferroni corrected p ≤ 0.016) with the branched-chain amino acid valine (per one standard deviation increment, +0.274 cm/s (95% conf…
Local Cerebral Blood Flow in a Rat Cortical Vein Occlusion Model
1996
The symptoms following sinus and vein occlusion observed in patients and experimental animals display a considerable variability that so far remains largely unexplained. In a rat cortical vein occlusion model using a photochemical thrombotic technique, we examined changes in the cerebral venous flow pattern by fluorescence angiography and regional cerebral blood flow (rCBF) and cerebral blood volume fraction (CBVF) by a modern laser Doppler “scanning” technique. Brain damage was assessed histologically. Fluorescence angiographic findings fell into two groups: group A, rats with an altered venous flow pattern after occlusion (n = 12), and group B, rats with interruption of blood flow and/or…
Echo-Doppler left ventricular filling abnormalities in patients with rheumatoid arthritis without clinically evident cardiovascular disease
1996
Our investigation aimed at verifying diastolic abnormalities in rheumatoid patients, without clinically evident cardiovascular disease and other confounding complaints, by using pulsed Doppler examination of transmitral blood flow. We selected 40 patients fulfilling revised American Rheumatism Association (ARA) criteria for the diagnosis of rheumatoid arthritis having no symptoms of cardiac disease or clinical findings of other extracardiac diseases. We also studied 40 rheumatoid-matched healthy volunteers as a control group. An echocardiographic examination was carried out on each subject. Left ventricular structural and functional measurements were obtained. Interventricular, septal thick…
Cerebral blood flow autoregulation during hypobaric hypotension assessed by laser Doppler scanning.
1994
Hypobaric hypotension was used to reduce systemic blood pressure in rats below the lower threshold of CBF autoregulation to evaluate a new laser Doppler (LD) “scanning” technique. Spontaneously breathing male Wistar Kyoto rats (n = 8) were anesthetized with chloral hydrate and the head fixed in a stereotaxic head holder. A cranial window with intact dura mater was introduced to assess local CBF (lCBF) by LD. One stationary probe served to detect rapid flow changes, whereas the second probe was used to sample lCBF recordings from many cortical locations by means of a stepping motor-controlled micromanipulator to obtain lCBF frequency histograms. Advantages are an improved spatial resolution…
MicroRNA-148b-3p and MicroRNA-25-3p Are Overexpressed in Fetuses with Late-Onset Fetal Growth Restriction
2019
<b><i>Objective:</i></b> It was the aim of this study to describe a microRNA (miRNA) profile characteristic of late-onset fetal growth restriction (FGR) and to investigate the pathways involved in their biochemical action. <b><i>Methods:</i></b> In this prospective study, 25 fetuses (16 normal and 9 with FGR [estimated fetal weight &#x3c;10th centile plus cerebroplacental ratio &#x3c;0.6765 multiples of the median]) were evaluated with Doppler ultrasound after 36 weeks. Afterwards, for every fetus, plasma from umbilical vein blood was collected at birth, miRNA was extracted, and full miRNA sequencing was performed. Subsequently, compa…