1,721,005 research outputs found
When to choose cardiac resynchronization therapy in chronic heart failure: Type and duration of the conduction delay
No full textCardiac resynchronization therapy (CRT) is an established treatment for patients with heart failure (HF), impaired left ventricular (LV) function, and wide QRS complex. The initial randomized clinical trials, which led to the widespread use of CRT, selected patients on the basis of QRS duration, not focusing on QRS morphology. However, recent evidences emphasized the role of left bundle branch block morphology in patients that underwent CRT in order to predict better response to therapy. Moreover, conventional right ventricular apical pacing might have long-term detrimental effects on cardiac structure and LV function, possibly leading to the development of HF. Therefore, current guidelines recommend upgrade from conventional pacemaker or implantable cardioverter-defibrillator to CRT or de novo CRT in patients with high (or expected high) percentage of ventricular pacing and reduced EF. We reviewed current knowledge on candidates' selection for CRT based on conduction delays that lead to electrical and mechanical dyssynchrony of the left ventricle
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
Management of macro-reentrant right atrial tachycardia around multiple leads aided by high-density mapping
No full textBackground: A 61-year-old male with Steinert Dystrophy and prior history of cardiac implantable device complained of highly symptomatic right atrial tachycardia. Unresponsive to pharmacological therapy. Methods: The patient underwent catheter ablation procedure aided by high-density mapping. Results: Ablation procedure was succesful. Conclusions: This unique case report highlights the role of high-density mapping in the identification of critical isthmus and management of macro-reentrant tachycardia in complex situations such as the presence of multiple leads in the chamber
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
Angina and left ventricular dysfunction: Can we 'reduce' it?
No full textDespite the evolution in pharmacology and devices, recurrent and persistent angina still represent a frequent issue in clinical practice. A 69-year-old Caucasian female patient has history of surgical aortic valve replacement with a bioprosthesis for severe aortic stenosis with subsequent transcatheter valve-in-valve implantation for bioprosthesis degeneration and single coronary artery bypass graft with left internal mammary artery on left anterior descending (LAD). After transcatheter aortic valve implantation, she started to complain angina [Canadian Cardiovascular Society (CCS) Class III], effectively treated with bisoprolol uptitration and ivabradine 5 b.i.d. addition. After 6 months, she had a non-ST segment elevated myocardial infarction with evidence of left main occlusion and good functioning aortic bioprosthesis. A retrograde drug-eluting balloon percutaneous coronary intervention (PCI) on LAD (in-stent restenosis) was performed. However, the patient continued to complain angina (CCS Class II-III), even after further ivabradine increase to 7.5 mg b.i.d. After 4 months, the patient underwent Reducer implantation. After 2 months, angina started to improve and the patient is currently angina free. In the last decades, PCI materials and stents greatly improved. Medical therapy (such as b-blockers) has been shown not only to improve symptoms but also to add a prognostic benefit in patients with reduced ejection fraction (EF). Ivabradine showed additional benefits in patients with angina and reduced EF. However, still a relevant portion of patients complain refractory angina. The COSIRA trial showed that a coronary sinus Reducer was associated with greater angina relief than the sham procedure and could be a further step in angina treatment
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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