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Arrhythmic risk prediction of acute myocarditis presenting with life-threatening ventricular tachyarrhythmias
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Miocardite: la grande simulatrice
No full textMyocarditis is a rare, but life threatening disease in childhood. It is most often due to common viral infections; less commonly, it may result from bacterial infections, immune mediated diseases or chemotherapy. Myocarditis may present with unspecific symptoms, ranging from respiratory to gastrointestinal ones; a clear hypomobility is the typical sign of myocarditis (“the immobile child”). The diagnosis is based on electrocardiogram and echocardiography, which are always pathologic but unspecific; an X-chest is useful to identify cardiomegaly. Among laboratory tests, the most sensitive element is an increased level of aspartate aminotransferase, while troponin dosage has low specificity and not absolute sensitivity. Endomyocardial biopsy is the gold standard diagnostic test, but it should be performed only in patients who do not respond to usual treatment, because of the high risk of side effects. The mainstay of therapy is supportive therapy for left ventricular dysfunction. The fulminant viral forms usually have initial significant cardiovascular impairment, followed by a complete resolution. On the other hand, a subacute disease might have less initial cardiovascular impairment, but more often can evolve to chronic dilated cardiomyopathy. In this case immunosuppressive therapy could be useful
Controversial issues and working practice in myocarditis: from scientific data to clinical grounds.
No full textAlthough the cause of myocarditis often remains unknown, a large variety of infections, systemic diseases, drugs and toxins have been associated with this disease. In most cases, myocarditis is induced by cardiotropic viruses and often evolves silently without discernible prognostic impact. However, in some patients, the lack of complete viral clearance and/or the association of a heart-specific inflammation can cause persistent myocyte damage, ultimately leading to progressive myocardial dilation and dysfunction or life-threatening arrhythmias. Spontaneous improvement of left ventricular function is described for 40-50% of patients. The diagnostic work-up and prognostic assessment of myocarditis should be multiparametric and all available resources should be employed, i.e. biomarkers of myocardial damage and ventricular dysfunction (troponin I, brain natriuretic peptide), advanced echocardiography, cardiac magnetic resonance and, in selected cases, endomyocardial biopsy (with histopathologic, immunohistochemical and virological analyses). These are the necessary prerequisites for an evidence-based and personalized management of myocarditis, which may require in some cases specific immunoactive treatments. However, controversial issues regarding diagnosis (such as role and timing of cardiac magnetic resonance imaging, role of endomyocardial biopsy) and therapy of myocarditis still remain unsolved. The purpose of this review is to analyze these crucial features in order to provide useful instructions for clinical practice
Myocarditis in Clinical Practice
No full textMyocarditis is a polymorphic disease characterized by great variability in clinical presentation and evolution. Patients presenting with severe left ventricular dysfunction and life-threatening arrhythmias represent a demanding challenge for the clinician. Modern techniques of cardiovascular imaging and the exhaustive molecular evaluation of the myocardium with endomyocardial biopsy have provided valuable insight into the pathophysiology of this disease, and several clinical registries have unraveled the disease's long-term evolution and prognosis. However, uncertainties persist in crucial practical issues in the management of patients. This article critically reviews current information for evidence-based management, offering a rational and practical approach to patients with myocarditis. For this review, we searched the PubMed and MEDLINE databases for articles published from January 1, 1980, through December 31, 2015, using the following terms: myocarditis, inflammatory cardiomyopathy, and endomyocardial biopsy. Articles were selected for inclusion if they represented primary data or were review articles published in high-impact journals. In particular, a risk-oriented approach is proposed. The different patterns of presentation of myocarditis are classified as low-, intermediate-, and high-risk syndromes according to the most recent evidence on prognosis, clinical findings, and both invasive and noninvasive testing, and appropriate management strategies are proposed for each risk class
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
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