Search results for "flow [Keywords]"
showing 10 items of 469 documents
Evidence of impaired coronary flow reserve and elevated microvascular resistances in a case of recurrent left apical ballooning.
2011
A 56-year old man was admitted for precordial pain associated with dyspnea and evidence of myocardial ischemia on ECG and cardiac ultrasound. His previous history included an episode of left apical ballooning five years before. At angiography, no evidence of significant epicardial coronary artery disease was manifest. Interestingly, both coronary flow reserve and the index of microvascular resistances were abnormal, showing evidence of impaired microvascular function. This is the first report providing direct evidence of microvascular dysfunction in a patient with (recurrent) apical ballooning.
Coronary plaque assessment of Vasodilative capacity by CT angiography effectively estimates fractional flow reserve.
2021
Abstract Background To evaluate the feasibility of non-invasive fractional flow reserve (FFR) estimation using histologically-validated assessment of plaque morphology on coronary CTA (CCTA) as inputs to a predictive model further validated against invasive FFR. Methods Patients (n = 113, 59 ± 8.9 years, 77% male) with suspected coronary artery disease (CAD) who had undergone CCTA and invasive FFR between August 2013 and May 2018 were included. Commercially available software was used to extract quantitative plaque morphology inclusive of both vessel structure and composition. The extracted plaque morphology was then fed as inputs to an optimized artificial neural network to predict lesion-…
GOLD and the fixed ratio
2012
We thank Dr Vestbo for his interest in our manuscript “Diagnosis of airway obstruction in the elderly: contribution of the SARA study” and for the opportunity to clarify some points. As mentioned in the title and aims, the intent of the paper is to offer a contribution to the open issue of identification of airway obstruction in elderly people.1 We agree with Dr Vestbo about the utility of distinguishing between the clinical and functional aspects of chronic obstructive pulmonary disease (COPD). We stress that, until the term COPD is used, diagnosis needs clinical evidence of a chronic pulmonary disease and functional evidence of airway obstruction. Given that symptoms compatible with COPD …
Diagnosis of silent coronary ischemia with selective coronary revascularization might improve 2-year survival of patients with critical limb-threaten…
2021
Abstract Background Patients with critical limb-threatening ischemia (CLTI) have had poor long-term survival after lower extremity revascularization owing to coexistent coronary artery disease. A new cardiac diagnostic test, coronary computed tomography-derived fractional flow reserve (FFRCT), can identify patients with ischemia-producing coronary stenosis who might benefit from coronary revascularization. We sought to determine whether the diagnosis of silent coronary ischemia before limb salvage surgery with selective postoperative coronary revascularization can reduce the incidence of adverse cardiac events and improve the survival of patients with CLTI compared with standard care. Metho…
Pre-operative Diagnosis of Silent Coronary Ischaemia May Reduce Post-operative Death and Myocardial Infarction and Improve Survival of Patients Under…
2019
Objective Patients undergoing peripheral vascular surgery have increased risk of death and myocardial infarction (MI), which may be due to unsuspected (silent) coronary ischaemia. The aim was to determine whether pre-operative diagnosis of silent ischaemia using coronary computed tomography (CT) derived fractional flow reserve (FFRCT) can facilitate multidisciplinary care to reduce post-operative death and MI, and improve survival. Methods This was a single centre prospective study with historic controls. Patients with no cardiac symptoms undergoing lower extremity surgical revascularisation with pre-operative coronary CTA-FFRCT testing were compared with historic controls with standard pre…
Quality-of-Life and Economic Outcomes of Assessing Fractional Flow Reserve With Computed Tomography Angiography: PLATFORM.
2015
International audience; BACKGROUND: Fractional flow reserve estimated using computed tomography (FFRCT) might improve evaluation of patients with chest pain. OBJECTIVES: The authors sought to determine the effect on cost and quality of life (QOL) of using FFRCT instead of usual care to evaluate stable patients with symptoms suspicious for coronary disease. METHODS: Symptomatic patients without known coronary disease were enrolled into 2 strata based on whether invasive or noninvasive diagnostic testing was planned. In each stratum, consecutive observational cohorts were evaluated with either usual care or FFRCT. The number of diagnostic tests, invasive procedures, hospitalizations, and medi…
Sensitivity of external resources to cash flow under financial constraints
2014
Abstract This paper explores the external financing–cash flow relationship in capital structure theory by comparing unlisted (financially constrained) and listed (financially unconstrained) companies. We postulate that investment is determined endogenously in the case of unlisted firms, as they are strongly dependent on internally generated funds (cash flow). Consequently, unlisted firms invest their cash flow in profitable projects, using any residual cash flow to increase their holdings of safe assets. In turn, listed companies determine their investment exogenously and may reduce leverage if they raise an excess of cash flow. As a result, listed companies would react more negatively to s…
Flow resistance law under suspended sediment laden conditions
2020
Abstract The uniform flow resistance equation, in the form due to Manning or Darcy-Weisbach, is widely applied to establish the stage-discharge relationship of a river cross-section. The application of this equation, namely the slope-area method, allows to indirectly measure the corresponding river discharge by measurements of bed slope, water level, cross-section area, wetted perimeter and an estimate of channel roughness. In this paper, a recently deduced flow resistance equation for open channel flow was tested during conditions of suspended sediment-laden flow. First, the flow resistance equation was determined by dimensional analysis and by applying the condition of incomplete self-sim…
Abatement of 1,1,2,2-tetrachloroethane in water by reduction at silver cathode and oxidation at boron doped diamond anode in micro reactors
2012
The treatment of aqueous solutions of 1,1,2,2-tetrachloroethane was performed by anodic oxidation at boron doped diamond (BDD), cathodic reduction at silver and coupled processes. Experiments were performed in macro and micro reactors with an interelectrode distance lower than 100. μm. Drastically higher abatements of the chlorinated compound and current efficiencies were obtained in microdevices that, furthermore, allowed to perform the electrolyses with low cell voltages in the absence of supporting electrolyte. When reduction and oxidation processes were carried out simultaneously in the microreactor, a higher abatement of pollutants was obtained with the same amount of the passed charge…
Microfluidic Preparation of Liquid Crystalline Elastomer Actuators
2018
This paper focuses on the microfluidic process (and its parameters) to prepare actuating particles from liquid crystalline elastomers. The preparation usually consists in the formation of droplets containing low molar mass liquid crystals at elevated temperatures. Subsequently, these particle precursors are oriented in the flow field of the capillary and solidified by a crosslinking polymerization, which produces the final actuating particles. The optimization of the process is necessary to obtain the actuating particles and the proper variation of the process parameters (temperature and flow rate) and allows variations of size and shape (from oblate to strongly prolate morphologies) as wel…