85 research outputs found

    Quantitative assessment of paravalvular regurgitation following transcatheter aortic valve replacement

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    Paravalvular aortic regurgitation (PAR) following transcatheter aortic valve implantation (TAVI) is well acknowledged. Despite improvements, echocardiographic measurement of PAR largely remains qualitative. Cardiovascular magnetic resonance (CMR) directly quantifies AR with accuracy and reproducibility. We compared CMR and transthoracic echocardiography (TTE) analysis of pre-operative and post-operative aortic regurgitation in patients undergoing both TAVI and surgical aortic valve replacement (AVR).Gareth Crouch, Phillip J Tully, Jayme Bennetts, Ajay Sinhal, Craig Bradbrook, Amy L Penhall, Carmine G De Pasquale, Robert A Baker, and Joseph B Selvanayaga

    Early and late changes in markers of aortic stiffness with breast cancer therapy

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    BACKGROUND: Anthracyclines and trastuzumab are well recognised to cause cardiac toxicity. Further to their effects on left ventricular (LV) function, anthracyclines in particular are considered to cause negative arterial remodelling. Whether these changes reverse is unknown. In addition, whether trastuzumab causes specific effects on arterial remodelling is yet undetermined. METHODS: Patients receiving these agents for treatment of breast cancer and healthy volunteers prospectively underwent clinical evaluation and cardiovascular magnetic resonance (CMR) imaging at baseline, 1, 4 and 14 months post-therapy, including functional assessment, measurement of aortic pulse wave velocity (PWV) using velocity encoded imaging and distensibility at ascending aorta (AA) and proximal descending aorta (PDA). RESULTS: Twenty-nine patients pretherapy and 12 volunteers demonstrated no differences in PWV, distensibility and LV function. Among cancer subjects, PWV increased acutely, P = 0.002 (4 months), then decreased by 14 months (P < 0.001). In addition, a decrease was observed in distensibility at the AA within 1 (P = 0.001) and 4 months (P < 0.001) of commencing therapy. At the PDA, only significant reduction was observed at 14 month distensibility when compared with baseline, P < 0.001. Patients with anthracycline exposure only had a greater reduction in aortic distensibility in the AA with time, P = 0.005 at 1 month, P < 0.001 at 4 months and P = 0.009 at 14 months. CONCLUSION: Acute changes are observed in PWV and distensibility at the AA following contemporary breast cancer chemotherapy and partially reverse a year after therapy is discontinued, with more severe effects seen with anthracyclines.S. Grover, P. W. Lou, C. Bradbrook, K. Cheong, D. Kotasek, D. P. Leong, B. Koczwara and J. B. Selvanayaga

    Micro-scale flood risk analysis based on detailed 2D hydraulic modelling and high resolution geographic data

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    peer reviewedThe paper presents a consistent micro-scale flood risk analysis procedure, relying on detailed 2D inundation modelling as well as on high resolution topographic and land use database. The flow model is based on the shallow-water equations, solved by means of a finite volume scheme on multiblock structured grids. Using highly accurate laser altimetry, the simulations are performed with a typical grid spacing of 2m, which is fine enough to represent the flow at the scale of individual buildings. Consequently, the outcomes of hydraulic modelling constitute suitable inputs for the subsequent exposure analysis, performed at a micro-scale using detailed land use maps and geographic database. Eventually, the procedure incorporates social flood impact analysis and evaluation of direct economic damage to residential buildings. Besides detailing the characteristics and performance of the hydraulic model, the paper describes the flow of data within the overall flood risk analysis procedure and demonstrates its applicability by means of a case study, for which two different flood protection measures were evaluated

    Gradations in digital inclusion: children, young people and the digital divide

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    Little academic and policy attention has addressed the `digital divide' among children and young people. This article analyses findings from a national survey of UK 9—19-year-olds that reveal inequalities by age, gender and socioeconomic status in relation to their quality of access to and use of the internet. Since both the extent of use and the reasons for low- and non-use of the internet vary by age, a different explanation for the digital divide is required for children compared with adults. Looking beyond the idea of a binary divide, we propose instead a continuum of digital inclusion. Gradations in frequency of internet use (from non and low users through to weekly and daily users) are found to map onto a progression in the take-up of online opportunities among young people (from basic through moderate to broad and then all-round users), thus beginning to explain why differences in internet use matter, contributing to inclusion and exclusion. Demographic, use and expertise variables are all shown to play a role in accounting for variations in the breadth and depth of internet use
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