1,720,963 research outputs found
Multiplanar review analysis of three dimensional echocardiographic datasets gives new insights into the morphology of subaortic stenosis
No full textAims Associated left ventricular structures may play a role in progression and recurrence of discrete subaortic stenosis. The availability of a new 3D echocardiography tool, multiplanar review (MPR), allows comprehensive analysis of datasets in infinite planes, and detailed examination of anatomy. We sought to evaluate the role of MPR in defining the morphology of subaortic stenosis.Methods Consecutive patients underwent detailed 2 and 3D echocardiographic examination using MPR.Results Sixteen patients aged 0.7–15.9 years (median 4.57) with diagnosis as follows: isolated subaortic stenosis in nine, additional defects in seven (coarctation of aorta, VSD, mitral, or aortic stenosis). Position and extent of subaortic stenosis was clearly described by multiplanar revew in all patients. Additional MPR findings were: abnormalities of mitral valve leaflet or chordal apparatus attachments (14 patients), abnormal ventricular muscle band (11), abnormal increased aorto-mitral separation (two). The aortoseptal angle was significantly decreased in subaortic stenosis, mean 141 ± 12°, vs. normal subjects, mean 153 ± 6°, P = 0.02. Surgical findings correlated well with MPR findings.Conclusions MPR analysis of 3D datasets is a sensitive and accurate mode for delineation of morphological details of discrete subaortic stenosis, providing additional information to 2D echocardiography
Impact of multiplanar review of three-dimensional echocardiographic data on management of congenital heart disease
No full textBackground: In patients with congenital cardiac malformations, accurate diagnosis is critical in diagnosis and management. The multiplanar review mode (MPR) allows the operator to cut three-dimensional (3D) echocardiographic data sets in infinite planes, and to review the moving image in three simultaneous orthogonal planes. We sought to describe the clinical utility of MPR of 3D echocardiography for analysis of congenitally malformed hearts.Methods: Cross-sectional and 3D MPR echocardiography was performed in 300 patients with congenitally malformed hearts.Results: Analysis in multiplanar mode was possible in all patients. New, clinically important information, which altered management or changed the principal diagnosis, was obtained in 32 (11%) cases. This determined suitability for biventricular repair in 11 patients, clarified the morphology of atrioventricular valves in 7, helped in assessment of aortic, mitral, or prosthetic valvar disease in 13, and identified a vascular ring in the other patient.Conclusions: 3D MPR is feasible in the setting of the congenitally malformed heart, permitting focused and in-depth analysis. This substantially improves the understanding of functional morphology, above the information derived from cross-sectional echocardiography. We recommend the use of the 3D format with MPR for patients with complex congenital cardiac disease
Multiplanar review of three-dimensional echocardiography gives new insights into the morphology of Ebstein's malformation
No full textIntroduction: We aimed to assess the ability of the multiplanar review modality of three-dimensional echocardiography to examine the dynamic morphology and the functional characteristics of malformed tricuspid valves in patients previously identified as having Ebstein’s malformation. Based on these characteristics, we attempted to differentiate Ebstein’s malformation from tricuspid valvar dysplasia.Methods: Using three-dimensional multiplanar review, analysed with either Qlab 6.0 or Tomtech Image Arena 3.0, we studied 23 patients, aged from 1 day to 70 years, previously diagnosed using cross-sectional echocardiography as having Ebstein’s malformation.Results: Using the features of rotational abnormality, and the orientation, of the effective tricuspid valvar orifice as diagnostic features of Ebstein’s malformation, we reclassified 11 patients (48 per cent) as exhibiting tricuspid valvar dysplasia. In addition, we studied the dynamic morphology as well as the function of the tricuspid valve. Surgical treatment was undertaken on 10 patients, revealing good correlation with the findings obtained using three-dimensional multiplanar review. In those with Ebstein’s malformation, we found varying degrees of rotation, with the effective valvar orifice always directed towards the right ventricular outflow tract. The opening of the orifice of dysplastic tricuspid valves, in contrast, was towards the apex of the right ventricle. The degree of delamination, and abnormalities of subcordal apparatus, were similar in the two groups.Discussion: Three-dimensional multiplanar review permits accurate definition of the dynamic morphology of Ebstein’s malformation, permitting clear differentiation from tricuspid valvar dysplasia.<br/
The angle of the components of the common atrioventricular valve predicts the outcome of surgical correction in patients with atrioventricular septal defect and common atrioventricular junction
No full textBackground: Three-dimensional echocardiography offers new insights into valvar function in atrioventricular septal defects (AVSDs). The aim of this study was to identify a morphological marker to predict the functional outcomes of left atrioventricular valves (AVVs) following the repair of AVSDs.Methods: Twenty-nine consecutive patients were evaluated preoperatively using 2-dimensional and 3-dimensional echocardiography. The angle of the AVV relative to the crux of the heart was measured in multiplanar review mode.Results: The severity of postoperative left AVV regurgitation was correlated with preoperative valvar angle, being more acute in patients with moderate or severe regurgitation (mean, 57 ± 13° vs 83 ± 9° in patients with no or mild regurgitation; P = .002). Angles ? 59° predicted severe regurgitation with 79% specificity.Conclusions: Multiplanar review of 3-dimensional data sets is valuable for the assessment of the functional morphology of AVSD valves. Using this technique, more acute AVV angles predicted increased likelihood of severe regurgitation following surgical repair.<br/
Tissue motion annular displacement of the mitral valve using two-dimensional speckle tracking echocardiology predicts the left ventricular ejection fraction in normal children
No full textBACKGROUND: The gold standard for determining the left ventricular ejection fraction is cardiac magnetic resonance imaging. Other parameters for determining the ejection fraction such as M-mode echocardiography are operator-dependant and often inaccurate. Assessment of the displacement of the mitral valve annulus using two-dimensional speckle tracking echocardiography may provide an accurate and simple method of determining the left ventricular ejection fraction in children.METHOD: We retrospectively studied 70 healthy 9-year-old children with no history of cardiovascular disease who had been assessed using cardiac magnetic resonance imaging and two-dimensional transthoracic echocardiography. Mitral displacement was determined using the tissue motion annular displacement (TMAD) feature of Philips QLAB version 9. The midpoint displacement of the mitral valve was calculated, and the predicted left ventricular ejection fraction was compared with magnetic resonance imaging-derived and M-mode-derived ejection fractions.RESULTS: The mean ejection fraction derived from magnetic resonance imaging (64.5 (4.6)) was similar to that derived from the TMAD midpoint (60.9 (2.7), p = 0.001) and the M-mode (61.9 (7), p = 0.012). The TMAD midpoint correlated strongly with the magnetic resonance imaging-derived ejection fraction (r = 0.69, p < 0.001), as did the predicted fraction (r = 0.67, p < 0.001). The M-mode ejection fraction showed a poor linear correlation with both magnetic resonance imaging-derived and TMAD-derived fractions (r = 0.33 and 0.04, respectively).CONCLUSION: TMAD of the mitral valve is a simple, effective, and highly reproducible method of assessing the ejection fraction in normal children. It shows a strong linear correlation with magnetic resonance imaging-derived ejection fraction and is superior to M-mode-derived ejection fractions.<br/
Increased regional deformation of the left ventricle in normal children with increased body mass index: implications for future cardiovascular health
No full textThe prevalence of obesity continues to increase in the developing world. The effects of obesity on the cardiovascular system include changes in systolic and diastolic function. More recently obesity has been linked with impairment of longitudinal myocardial deformation properties in children. We sought to determine the effect of increased body mass index (BMI) on cardiac deformation in a group of children taking part in the population-based Southampton Women’s Survey to detect early cardiovascular changes associated with increasing BMI before established obesity. Sixty-eight children at a mean age of 9.4 years old underwent assessment of longitudinal myocardial deformation in the basal septal segment of the left ventricle (LV) using two-dimensional speckle tracking echocardiography. Parameters of afterload and preload, which may influence deformation, were determined from cardiac magnetic resonance imaging. BMI was determined from the child’s height and weight at the time of echocardiogram. Greater pediatric BMI was associated with greater longitudinal myocardial deformation or strain in the basal septal segment of the LV (? = 1.6, p < 0.001); however, this was not related to contractility or strain rate in this part of the heart (? = 0.001, p = 0.92). The end-diastolic volume of the LV increased with increasing BMI (? = 3.93, p < 0.01). In young children, regional deformation in the LV increases with increasing BMI, whilst normal contractility is maintained. This effect may be explained by the increased preload of the LV associated with increased somatic growth. The long-term implications of this altered physiology need to be followed-u
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
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
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