1,720,970 research outputs found
Management of atrial high-rate episodes detected by cardiac implanted electronic devices
No full textCardiac implanted electronic devices (CIEDs), including pacemakers and implantable defibrillators that perform atrial sensing typically using an atrial electrode, frequently detect subclinical atrial high-rate episodes (AHREs). When the intracardiac electrograms are carefully examined, the majority of AHREs are atrial fibrillation (AF) or other atrial tachyarrhythmias, which have been shown to be associated with both an increased risk of stroke, and subsequent development of clinical AF. However, the absolute risk of stroke among patients with AHREs is less than might be expected for clinically diagnosed paroxysmal AF. In addition, a close temporal relationship between AHREs and stroke is seen in only 15% of strokes in patients with a CIED: the majority have either no AHREs before the stroke, or AHREs very distant from incident stroke, suggesting that AHREs might be more of a risk marker than a risk factor for stroke. Management of AHREs should not be the same as for clinical AF, and a degree of uncertainty underpins the rationale for much-needed, ongoing, randomized trials of oral anticoagulation in patients with CIED-detected AHREs. We propose a management algorithm that takes into account both the stroke risk and the AHRE burden, but highlights the current uncertainty and evidence gaps for this condition.</p
Device-detected atrial fibrillation and risk for stroke: an analysis of >10 000 patients from the SOS AF project (Stroke preventiOn Strategies based on Atrial Fibrillation information from implanted devices)
Full text linkObjective: The aim of this study was to assess the association between maximum daily atrial fibrillation (AF) burden and risk of ischaemic stroke. Background: Cardiac implanted electronic devices (CIEDs) enhance detection of AF, providing a comprehensive measure of AF burden. Design, setting, and patients A pooled analysis of individual patient data from five prospective studies was performed. Patients without permanent AF, previously implanted with CIEDs, were included if they had at least 3 months of follow-up. A total of 10 016 patients (median age 70 years) met these criteria. The risk of ischaemic stroke associated with pre-specified cut-off points of AF burden (5 min, 1, 6, 12, and 23 h, respectively) was assessed. Results: During a median follow-up of 24 months, 43% of 10 016 patients experienced at least 1 day with at least 5 min of AF burden and for them the median time to the maximum AF burden was 6 months (inter-quartile range: 1.3–14). A Cox regression analysis adjusted for the CHADS2 score and anticoagulants at baseline demonstrated that AF burden was an independent predictor of ischaemic stroke. Among the thresholds of AF burden that we evaluated, 1 h was associated with the highest hazard ratio (HR) for ischaemic stroke, i.e. 2.11 (95% CI: 1.22–3.64, P = 0.008). Conclusions: Device-detected AF burden is associated with an increased risk of ischaemic stroke in a relatively unselected population of CIEDs patients. This finding may add to the basis for timely and clinically appropriate decision-making on anticoagulation treatment.Version of Recor
Detection of new atrial fibrillation in patients with cardiac implanted electronic devices and factors associated with transition to higher device-detected atrial fibrillation burden
Full text linkBackground: In patients with cardiac implanted electronic devices, detection of new atrial fibrillation (AF) is associated with an increased risk of stroke. Objective: To characterize daily AF burden at first detection and the rate of temporal transition to higher device-detected AF burden. Methods: A pooled analysis of data from 3 prospective projects was analyzed, and 6580 patients (mean age 68 ± 12 years, 72% male) with no history of AF and no use of anticoagulants at baseline were identified. Various thresholds of daily AF burden (5 minutes and 1, 6, 12, and 23 hours) were analyzed. Results: Among the study population of 6580 patients, a new AF, with an AF burden of ≥5 minutes, was detected in 2244 patients (34%) during a follow-up period of 2.4 ± 1.7 years. Among these patients, 1091 (49.8%) transitioned to a higher AF-burden threshold during follow-up. A higher duration of daily AF burden manifest at first detection and CHADS2 score ≥2 were associated with faster transition to a subsequent higher burden. Approximately 24% of patients transitioned from a lower threshold to a daily AF burden of ≥23 hours during follow-up. Conclusion: More than one-third of patients with no history of AF developed device-detected AF, with attainment of different thresholds of daily AF burden over time. Continuous long-term monitoring, especially when the initial detection corresponds to a higher daily AF burden and the CHADS2 score is ≥2, could support timely clinical decisions on anticoagulation by capturing transitions to higher AF-burden thresholds
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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