1,720,956 research outputs found
Effect of Echocardiographic Grading of Left Ventricular Diastolic Dysfunction by Different Classifications in Primary Care
No full textThe presence of left ventricular (LV) diastolic dysfunction (DD) as characterized by Doppler echocardiography is associated with worse overall mortality both in symptomatic and asymptomatic patients. However, available data on this topic come from referral centers and have been obtained by different, validated algorithms for each single study. Thus, we aimed at determining the feasibility of comprehensive evaluation of LVDD in a primary care outpatient setting and at testing the concordance of different methodological approaches in grading diastolic dysfunction. Eight hundred eighty-five consecutive outpatients, in sinus rhythm, prospectively underwent Doppler echocardiography according to a predetermined protocol. Feasibility of each LV diastolic index and concordance between 3 methods to determine the degree of LVDD, namely the American Society of Echocardiography/European Association of Echocardiography (ASE/EAE) recommendations, the Olmstead County, and the Canberra Study protocols, were tested. Feasibility of all diastolic indexes was high, ranging from 93% of Valsalva maneuver to ≥99% for mitral inflow and tissue Doppler parameters. Diastolic function was not classifiable in 6% to 19% of patients. The concordance for LV diastolic dysfunction degree was fair when comparing the classification of the ASE/EAE with those from Olmstead County (κ = 0.25; reclassification rate 51%) and Canberra Study (κ = 0.27; reclassification rate 43.7%), and was good for the comparison between the Olmstead County and Canberra classifications (κ = 0.68, reclassification rate 27%). In conclusion, feasibility of LV diastolic function measurements is very high and grading diastolic dysfunction is possible in most patients in primary care settings. Substantial differences, however, exist when concordance is tested among 3 documented criteria, resulting in poor concordance of data interpretation and hence patient stratification and clinical management
Association of left ventricular longitudinal and circumferential systolic dysfunction with diastolic function in hypertension: a nonlinear analysis focused on the interplay with left ventricular geometry
No full textBackground The relationships of left ventricular (LV) longitudinal and circumferential systolic dysfunction with diastolic performance in hypertensive patients have never been compared. Methods and Results In 532 asymptomatic hypertensive patients, circumferential function was assessed with the use of midwall fractional shortening (mFS) and stress-corrected mFS (SCmFS), whereas longitudinal function was assessed with the use of left atrioventricular plane displacement (AVPD) and systolic mitral annulus velocity (s′). Early diastolic annular velocity (e′) and the E/e′ ratio were measured. Global longitudinal and circumferential strain were determined in a subset of 210 patients. e′ was linearly related to all systolic indexes (AVPD: R = 0.40; s′: R = 0.39; mFS: R = 0.16; SCmFS: R = 0.17; all P <.0001), but the correlations were stronger with longitudinal indexes than with circumferential ones (P <.0001). E/e′ was nonlinearly related to AVPD (R = -0.49; P <.0001) and s′ (R = -0.34; P <.0001) and showed no relationship with mFS and SCmFS. Longitudinal indexes were superior to circumferential ones in predicting e′ <8 cm/s, E/e′ <8, and E/e′ ≥13. The effect of LV geometry on LV diastolic function was evident among patients with preserved systolic longitudinal function, but was blunted among patients with impaired longitudinal function. In multivariable analyses, only longitudinal indexes remained associated with e′ and E/e′. Analyses using strains provided similar results. Conclusions In asymptomatic hypertensive subjects, LV diastolic performance is independently associated with longitudinal systolic dysfunction, but not with circumferential systolic dysfunction. Subtle longitudinal systolic impairment plays a role in mediating the effect of LV geometry on diastolic performance. These findings may support the need of critically revising the concept of isolated diastolic dysfunction in these patients
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Feasibility and relevance of right parasternal view for assessing severity and rate of progression of aortic valve stenosis in primary care
Full text linkBackground Right parasternal view (RPV) is important in assessing the severity of aortic stenosis (AS). However, the feasibility and relevance of RPV in primary care is unresolved. Moreover, information regarding the role of RPV in the evaluation of the hemodynamic progression of AS is lacking. Methods Consecutive patients with peak aortic valve velocity (Vmax) ≥ 2.5 m/s were prospectively enrolled in a primary care echocardiographic laboratory. Aortic Doppler parameters were evaluated from apical view and RPV. Results The total number of enrolled patients was 330 (aged 81 ± 11 years, 47% female, left ventricular ejection fraction 64 ± 9%). The RPV was feasible in 275 (83%). Vmax and Mean Gradient were significantly higher and aortic valve area was significantly lower from RPV as compared to apical view (p < 0.0001 for all). Reclassification of severity towards either moderate or severe AS occurred in 13–26% of patients, according to different criteria, when evaluated from RPV. Among 108 patients (40%) undergoing multiple examinations the rate of progression was lower from the apical approach than from the RPV (0.19 ± 0.20 m/s/year vs. 0.24 ± 0.27 m/s/year, respectively; p = 0.03), and was fast (> 0.3 m/s/year) in 17 patients (16%) from the apical window vs. 26 patients (24%) from RPV (p < 0.0001). Conclusion Implementing RPV is feasible in primary care and results in a substantial reclassification rate through the entire spectrum of AS severity. Our data also suggest a potential role of Doppler interrogation from multiple windows to improve AS progression assessment
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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