Search results for " blood flow"
showing 10 items of 305 documents
Exploring metrics for the characterization of the cerebral autoregulation during head-up tilt and propofol general anesthesia
2022
Techniques grounded on the simultaneous utilization of Tiecks' second order differential equations and spontaneous variability of mean arterial pressure (MAP) and mean cerebral blood flow velocity (MCBFV), recorded from middle cerebral arteries through a transcranial Doppler device, provide a characterization of cerebral autoregulation (CA) via the autoregulation index (ARI). These methods exploit two metrics for comparing the measured MCBFV series with the version predicted by Tiecks' model: normalized mean square prediction error (NMSPE) and normalized correlation rho. The aim of this study is to assess the two metrics for ARI computation in 13 healthy subjects (age: 27 & PLUSMN; 8 yr…
Rationale and design of dal-VESSEL: a study to assess the safety and efficacy of dalcetrapib on endothelial function using brachial artery flow-media…
2011
Dalcetrapib increases high-density lipoprotein cholesterol (HDL-C) levels through effects on cholesteryl ester transfer protein (CETP). As part of the dalcetrapib dal-HEART clinical trial programme, the efficacy and safety of dalcetrapib is assessed in coronary heart disease (CHD) patients in the dal-VESSEL study (ClinicalTrials.gov identifier: NCT00655538), the design and methods of which are presented here. RESEARCH DESIGN AND STUDY METHOD: Men and women with CHD or CHD risk equivalent, with HDL-C levels50 mg/dL were recruited for a 36-week, double-blinded, placebo-controlled trial. After a pre-randomisation phase of up to 8 weeks, patients received dalcetrapib 600 mg/day or placebo in …
Relationships between maximal oxygen uptake and endothelial function in healthy male adults: a preliminary study
2010
Aerobic capacity, as indicated by maximal oxygen uptake (VO(2) max) has an important role in contrasting the traditional cardiovascular risk factors and preventing cardiovascular morbidity and mortality. It is known that endothelial function, measured as flow-mediated dilation (FMD) of the brachial artery, is strictly linked to atherogenesis and cardiovascular risk. However, the relationship between VO(2) max and FMD has not been fully investigated especially in healthy non-obese subjects. This preliminary study cross-sectionally investigated the relationship between VO(2) max and FMD in 22 non-obese, healthy sedentary male subjects. Dividing the cohort in two subgroups of 11 subjects each …
Interictal Hyperperfusion in the Higher Visual Cortex in Patients With Episodic Migraine.
2019
Background Migraine pathophysiology is complex and probably involves cortical and subcortical alterations. Structural and functional brain imaging studies indicate alterations in the higher order visual cortex in patients with migraine. Arterial spin labeling magnetic resonance imaging (ASL-MRI) is a non-invasive imaging method for assessing changes in cerebral blood flow (CBF) in vivo. Objective To examine if interictal CBF differs between patients with episodic migraine (EM) with or without aura and healthy controls (HC). Methods We assessed interictal CBF using 2D pseudo-continuous ASL-MRI on a 3 Tesla Philips scanner (University Hospital Zurich, Switzerland) in EM (N = 17, mean age 32.7…
Dose-dependent effects of decaffeinated coffee on endothelial function in healthy subjects
2009
ackground/Objectives: Coffee is known to contain antioxidant substances whose effects may be blunted because of caffeine that may unfavorably affect the cardiovascular system. This study was designed to investigate the acute dose-dependent effects of decaffeinated coffee (DC) on endothelial function measured by the brachial artery flow-mediated dilation (FMD). Subjects/Methods: A total of 15 (8 men and 7 women) healthy nonobese subjects underwent a single-blind, crossover study. Subjects ingested one and two cups of decaffeinated Italian espresso coffee in random order at 5- to 7-day intervals. Results: In the hour following the ingestion of two cups of DC, FMD increased (mean±s.e.m.): 0 mi…
Erectile dysfunction is associated with low total serum testosterone levels and impaired flow-mediated vasodilation in intermediate risk men accordin…
2015
Background: The role erectile dysfunction (ED) coupled with low testosterone levels as early markers of atherosclerosis is not well understood. Objectives: To analyze the relationship between serum testosterone levels with both ED and brachial artery flow-mediated vasodilation (FMD), in a primary prevention sample of men. Methods: We enrolled 802 asymptomatic, intermediate CV risk patients, according to the Framingham Risk Score, aged 40e80 years, who underwent the ultrasound examination of FMD, the evaluation of ED and the assessment of total serum testosterone levels. Results: Testosterone levels correlated both with FMD (r ¼ 0.85; p < 0.0001) and IIEF-5 score (rs ¼ 0.65; p < 0.0001…
Noninvasive assessment of pulmonary hemodynamics in patients with chronic thromboembolic pulmonary hypertension by high temporal resolution phase-con…
2013
Background— Right heart catheterization is the gold standard for assessment of pulmonary hemodynamics in patients with chronic thromboembolic pulmonary hypertension. To date, MRI has not been able to produce precise measurements of mean pulmonary arterial pressure (mPAP). The purpose of the study was to create a model for estimating mPAP and pulmonary vascular resistance in patients with chronic thromboembolic pulmonary hypertension by high temporal resolution phase-contrast MRI (PC-MRI) and to correlate the results with simultaneously acquired, invasive catheter-based measurements (simultaneously measured mPAP) and with right heart catheterization measurements. Methods and Results— A tota…
Breathing 100% oxygen during water immersion improves postimmersion cardiovascular responses to orthostatic stress
2016
Abstract Physiological compensation to postural stress is weakened after long‐duration water immersion (WI), thus predisposing individuals to orthostatic intolerance. This study was conducted to compare hemodynamic responses to postural stress following exposure to WI alone (Air WI), hyperbaric oxygen alone in a hyperbaric chamber (O 2 HC), and WI combined with hyperbaric oxygen (O 2 WI), all at a depth of 1.35 ATA, and to determine whether hyperbaric oxygen is protective of orthostatic tolerance. Thirty‐two healthy men underwent up to 15 min of 70° head‐up tilt (HUT) testing before and after a single 6‐h resting exposure to Air WI ( N = 10), O 2 HC ( N = 12), or O 2 WI ( N = 10). Heart …
Symptomatic Deep Femoral Artery Pseudoaneurysm Endovascular Exclusion. Case Report and Literature Review.
2017
Deep femoral artery pseudoaneurysms (DFAPs) are rare and generally occur after penetrating trauma or surgical procedures. A 36-year-old obese man presented with pain in correspondence of the anterior-lateral thigh after 6 months from gunshot wound. Duplex and computed tomography (CT) showed a bilobed right DFAP (maximal diameter 12.9 cm). The patient was managed urgently, under local anesthesia, by placement in the distal DFA of a Viabahn 8 Ã 100-mm stent graft (W L Gore & Associates, Inc). The postoperative course was uneventful, and the 24-month CT showed regular stent-graft patency and 20-mm DFAP shrinkage. The literature review reported 8 cases of DFAPs; of these 6 were managed by endo…
Ambulatory follow-up of aortic dissection by transesophageal two-dimensional and color-coded Doppler echocardiography.
1989
Follow-up of 18 patients with aortic dissection (five with type I, one with type II, 11 with type III dissection according to DeBakey) by transesophageal, two-dimensional and color-coded Doppler echocardiography showed a persistence of the false lumen in five of seven patients (71%) after surgery and in nine of 11 patients (82%) after medical therapy. In two patients treated with surgery, the dissected part of the aorta had been resected, whereas in two patients treated medically, a progressive and complete obliteration of the false lumen was observed. In the false lumen, thrombus formation was absent in four, localized in four, and progressive in six patients. Flow within the false lumen c…