1,721,059 research outputs found
Different Phases of Disease in a Highly Characterized Cohort of Lymphocytic Myocarditis: Clinical and Electrophysiological Characteristics
No full textIntroduzione: la biopsia endomiocardica (BEM) è un esame diagnostico necessario per confermare il sospetto clinico di miocardite linfocitaria (ML) e per identificarne l’eziologia. La BEM fornisce quelle informazioni istologiche ed immunoistochimiche fondamentali per distinguere le varie fasi di malattia. Obiettivi: lo scopo dello studio consiste nella caratterizzazione e comparazione degli aspetti clinici ed elettrofisiologici associati alle varie fasi anatomopatologiche di malattia nei pazienti con diagnosi di ML confermata dalla BEM. Metodi: è stato condotto uno studio prospettico e multicentrico, in cui sono stati inclusi tutti i pazienti con una diagnosi di ML valutati presso tre centri italiani di riferimento per la cura delle aritmie. Sulla scorta delle risultanze anatomopatologiche ed in accordo a quanto presente nella Letteratura, è stata applicata una classificazione che individua le seguenti tre fasi di malattia: ML acuta (MLA), ML cronica attiva (MLCA) e miocardite guarita (MG). I tre gruppi così ottenuti sono stati confrontati in termini di presentazione clinica e risultanze degli accertamenti diagnostici non invasivi ed invasivi. Risultati: nei 122 pazienti inclusi nello studio (MLA, n=44; MLCA, n=42; MG, n= 36), le aritmie ventricolari complesse sono state riscontrate frequentemente in ciascuna fase di malattia (n=109, 89%), ma la fibrillazione ventricolare è risultata essere più comune nella MLA (p=0.028). Alla risonanza magnetica cardiaca, il Late Gadolinium Enhancement (LGE) è stato osservato con maggiore frequenza nei pazienti con MG e MLCA rispetto ai pazienti con MLA (94.4% vs. 92.9% vs. 50%, p<0.002), mentre l’edema miocardico è stato riscontrato più spesso nella MLA che nella MLCA, risultando completamente assente nella MG (90.9% vs. 50% vs. 0%; p<0.001). Pertanto, l’edema miocardico è risultato essere il migliore predittore clinico indipendente dell’infiammazione miocardica confermata dalla BEM. Al mappaggio elettroanatomico, sono state riscontrate meno frequentemente aree di basso voltaggio nella MLA rispetto alla MLCA o alla MG. Inoltre, è stata osservata una associazione regionale significativa tra l’edema in uno specifico segmento miocardico e la presenza di elettrogrammi di normale ampiezza nella medesima sede (OR=0.24 [0.10-0-54]; p<0.01), oltre che tra LGE ed aree di basso voltaggio (OR=2.86 [1.19-6.97]; p=0.019). L’estensione delle aree di basso voltaggio è risultata essere associata all’inducibilità di aritmie ventricolari sostenute mediante stimolazione ventricolare programmata (p=0.03), specialmente nei pazienti con MG. Conclusioni: la ML è una patologia altamente eterogenea e le sue diverse fasi presentano caratteristiche cliniche, morfologiche ed elettrofisiologiche specifiche. Saranno necessari ulteriori studi per identificare potenziali marcatori elettroanatomici dell’infiammazione miocardica.Background: endomyocardial biopsy (EMB) is required to make a definite diagnosis of lymphocytic myocarditis (LM), to identify its etiology, and to classify LM into different phases. Objective: to characterize and compare clinical and electrophysiological characteristics of different biopsy-proven LM phases, namely acute myocarditis (AM), chronic active myocarditis (CAM), and healed myocarditis (HM). Methods: all patients with a diagnosis of LM at three Italian referral centers were prospectively enrolled. According to EMB findings, LM was classified as AM, CAM, or HM; per-group comparisons of clinical presentations, non-invasive, and invasive findings are reported. Results: among the 122 enrolled patients (AM: n=44; CAM: n=42; HM: n=36), complex ventricular arrhythmias were very common overall (n=109, 89%), but ventricular fibrillation was slightly more prevalent in AM (p=0.028). Cardiac magnetic resonance imaging showed late gadolinium enhancement (LGE) in more patients with HM and CAM than AM (94.4% vs. 92.9% vs. 50%; p<0.001), while edema was more common in AM than in CAM, being absent in HM (90.9% vs. 50% vs. 0%; p<0.001). Accordingly, edema was the strongest independent clinical predictor of EMB-proven active inflammation. Electroanatomical mapping revealed a lower prevalence of low-voltage areas (LVAs) in AM than in CAM or HM. We observed a strong association between edema at a specific myocardial segment and normal voltages at that site (OR=0.24 [0.10 – 0.54]; p<0.01), as well as between LGE and LVAs (OR=2.86 [1.19 – 6.97]; p=0.019). The extension of LVAs was linked to inducibility by programmed electrical stimulation (p=0.03), with maximal association in HM. Conclusions: LM is a highly heterogeneous disease, and its different phases are characterized by diverse clinical, morphological, and electrophysiological features. Further research is required to identify electroanatomical markers of inflammation
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Pulsed-field ablation of atrial fibrillation: kinetics of release of multiple cardiac biomarkers
Full text linkGoing 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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