1,720,996 research outputs found
Wish you were (not) here : a patent foramen ovale closure device embolization
No full textA 59-year-old asymptomatic man, with a history of previous transient ischaemic attack and patent foramen ovale (PFO) closure with an Amplatzer 24-mm atrial septal defect occluder device (Abbott Vascular; Abbott Park, IL, USA), performed in another centre 15 months before, was admitted to our hospital for a routine echocardiographic follow-up. Transthoracic echocardiogram showed the absence of the occluder device in the interatrial septum and a huge septal aneurysm with moderate right-to-left shunt detected after saline injection during Valsalva manoeuvre (Figure Figure11, Supplementary material online, Videos S1 and S2). Subsequently, the patient underwent computed tomography angiography of the thoracoabdominal aorta, which confirmed the migration of the device in the aortic arch (Figure Figure22). Considering the high risk of complications due to percutaneous management, the patient was scheduled for a surgical retrieval of the device.
Patent foramen ovale closure device embolization is rare and typically occurs early after deployment. Common sites of migration are cardiac chambers, pulmonary artery, aortic arch, descending and abdominal aorta. Reported anatomical predisposing factors are an atrial septal aneurysm, a thick septum secundum (>10 mm) or a long tunnel.1 In our case, we believe that an undersized device together with the large atrial septal aneurysm was the possible mechanism for the failure of the PFO repair. Larger devices are usually indicated in cases of atrial septal aneurysm in order to cover the entire redundant septum. We can suppose the embolization occurred early, but we don’t have any previous echocardiographic images available for comparison. A successfully placed PFO closure device straddles the thick muscular septum secundum with its two disks and is subsequently covered up and stabilized by endothelial tissue, so the long-term dislodgement is uncommon.2 Given the inability of these devices to retract and compress, as they would when initially implanted,3 to allow the passage into a vascular sheath, often an open-heart surgical approach is recommended
Tri-ponderal mass index and left ventricular hypertrophy in a cohort of obese Caucasian children and adolescents
No full textPediatric obesity is an emerging global burden for society among its health related consequences, there are hypertension (HTN) and left ventricular hypertrophy (LVH). Several anthropometric indices have been investigated for the early identification of
cardiovascular risk in children. The aim of the present study was to assess whether tri-ponderal mass index (TMI) was associated with LVH in a cohort of obese Caucasian children and adolescents
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
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
Corrigendum to “Contribution of central and peripheral factors at peak exercise in heart failure patients with progressive severity of exercise limitation.” [Int. J. Cardiol. 248 (2017) 252–256]
No full textThe affiliation of Stefania Paolillo was mentioned incorrectly in the original article and this has now been corrected. The authors would like to apologize for any inconvenience caused
Contribution of central and peripheral factors at peak exercise in heart failure patients with progressive severity of exercise limitation
No full textBackground A reduced cardiac output (CO) response during exercise is a major limiting factor in heart failure (HF). Oxygen consumption (VO2) is directly proportional to CO. Peripheral mechanisms via arteriovenous oxygen difference (Δ(a-v)O2) play a pivotal role in chronic HF. We hypothesized a weak correlation between peak VO2 and peak CO with a greater Δ(a-v)O2 variability in most severe HF. Methods We analyzed 278 HF patients (NYHA II–III) who performed maximal cardiopulmonary exercise test with non-invasive CO measurement by inert gas rebreathing. Results Median peakVO2, CO and Δ(a-v)O2 were 0.96 (0.78–1.28) L/min, 6.3 (5.1–8.0) L/min and 16.0 (14.2–18.0) mL/100 mL respectively, with a linear relationship between VO2 and CO: CO = 5.3 × VO2 + 1.13 (r2 = 0.705, p < 0.001). Patients were grouped according to exercise limitation. Group 1 (101 patients) peakVO2 < 50% pred: peakVO2 0.80 (0.67–0.94) L/min, peakCO 5.6 (4.7–6.5) L/min, peakΔ(a-v)O2 14.8 (12.9–17.1) mL/100 mL. Group 2 (89 patients) peakVO2 ≥ 50–<65% pred: peakVO2 1.02 (0.84–1.29) L/min, peakCO 6.4 (5.1–8.0) L/min, peakΔ(a-v)O2 16.7 (15.0–18.5) mL/100 mL. Group 3 (88 patients) peakVO2 ≥ 65% pred: peakVO2 1.28 (0.93–1.66) L/min, peakCO 8.0 (6.2–9.7) L/min, peakΔ(a-v)O2 16.8 (14.6–18.3) mL/100 mL. A peakVO2 and peakCO linear relationship was observed in Group 1 (r2 = 0.381, p < 0.001), Group 2 (r2 = 0.756, p < 0.001) and Group 3 (r2 = 0.744, p < 0.001). Conclusions With worsening HF we observed a progressive reduction of peak CO and peak VO2. However in most compromised patients also peripheral mechanisms play a role as indicated by reduced Δ(a-v)O2
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