1,720,974 research outputs found
Reduced coronary flow reserve and parasympathetic dysfunction in patients with cardiovascular syndrome X
No full textOBJECTIVE:
Although cardiovascular syndrome X was described many years ago, its causes are still unclear. Many studies have addressed the autonomic function, whereas others have investigated the coronary reserve. The purpose of this study was to investigate the correlations between parasympathetic dysfunction and coronary flow reserve deficiency.
BASIC METHODS:
Eleven consecutive women suffering from cardiovascular syndrome X were enrolled in the study. All the patients underwent the analysis of heart rate and blood pressure variability, the cold face test and noninvasive evaluation of the coronary flow reserve by transthoracic echocardiography. Comparison was made with healthy volunteers.
RESULTS:
Seven patients (64%) showed vagal impairment in the analysis of heart rate and blood pressure variability and a pathological response to the cold face test, whereas four patients (36%) did not show significant differences from the control group. In these three groups, patients with and without vagal impairment and controls, there was a difference in the mean diastolic coronary velocity reserve (1.94+/-0.48; 3.73+/-0.95, 2.88+/-0.55, P=0.0005) and in maximal diastolic velocity reserve (2.00+/-0.48, 3.26+/-0.64, 2.65+/-0.57, P=0.0047). Post-hoc analysis demonstrated that the mean and maximal diastolic velocity reserves of the patients with vagal impairment seemed to be reduced compared with those of the other groups (P<0.05), which were similar.
CONCLUSIONS:
This study confirmed that syndrome X patients represent a heterogeneous group. More than half of the patients exhibited vagal dysfunction. In these patients, coronary flow reserve was abnormal compared with controls and other syndrome X patients without vagal impairment
Repair of anomalous right and circumflex coronary arteries arising from the pulmonary artery.
No full textRepair of anomalous circumflex and right coronary artery arising from the pulmonary arter
Factors affecting left ventricular remodelling and mechanics in the long-term follow-up after successful repair of aortic coartaction
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Left ventricular remodeling, systolic function, and diastolic function in young adults with beta-thalassemia intermedia: A Doppler echocardiography study
No full textBackground: The aim of this study was to investigate the left ventricular (LV) remodeling and function in 24 asymptomatic young adults affected by β-thalassemia intermedia (TI), in order to compare the obtained data with that of 80 patients affected by β-thalassemia major (TM) and 65 healthy subjects. Methods: LV volumes and shapes, mass index, mass/volume ratio, systolic and diastolic function, stroke volume, and cardiac index were determined by two-dimensional and M-mode echocardiography. Results: In the TM and TI groups, LV volumes, diastolic and systolic shapes were significantly different from the control subjects, but the ejection fraction was slightly reduced only in the TM group. The TI group had larger LV volumes than did the TM group (mean [± SD] end-diastolic volume index, 99.4 ± 21.9 vs 82.7 ± 21.5 mL/m2, respectively [p < 0.005]; mean end-systolic volume index, 42.8 ± 12.2 vs 36.1 ± 12.9 mL/m2, respectively [p < 0.05]). Both groups showed an increase of the LV mass index, but the mass/volume ratio did not differ from the control subjects. The systolic volume index and the cardiac index were increased in both groups, but the increase was more pronounced in the TI group. Fractional shortening (FS) and the mean velocity of circumferential shortening (mVCFc) were decreased in the TM group (FS, 33.6 ± 5.5% vs 36.9 ± 4.1, respectively [p < 0.001]; mVCFc, 1.06 ± 0.18 vs 1.17 ± 0.12 circumference per second, respectively [p < 0.0001]). The LV contractile state was depressed only in the TM group, and the preload index was normal in both. LV filling showed an increase in the total flow velocity integral due to increases in the peak E wave (E) and peak A wave (A) velocities and integrals, with an increase of the E/A ratio in the TM group and a slight decrease in the TI group. The isovolumic relaxation time was prolonged in both groups. There was no major derangement in the pulmonary venous flow. Conclusions: Asymptomatic young adults with TI show significant increases in LV volumes, LV mass, and cardiac index that are more pronounced than those in TM patients. LV systolic function is preserved in the TI group but is slightly depressed in the TM group due to the increase of afterload and to reduced contractility. The hemodynamic and hematologic factors involved in the etiopathogenesis of these findings are discussed, such as the treatment strategy. © 2002 Elsevier Science Ltd. All rights reserved
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
Echocardiographic evaluation of systolic and diastolic left ventricular function following arterial switch operation in neonatal period for transposition of the great arteries. Midterm results.
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