1,720,965 research outputs found
CHADS2 and CHA2DS2-VASc scores to predict morbidity and mortality in heart failure patients candidates to cardiac resynchronization therapy
No full textAimsCHADS2 and CHA2DS2-VASc scores are pivotal in assessing the risk of stroke in atrial fibrillation patients, and were recently proved to predict hospitalizations and mortality in specific clinical settings. Aim of this study was to evaluate whether these scores could predict clinical outcomes [first hospitalization for heart failure (HF) and a combined event of HF hospitalization and death for any cause] in patients candidates to cardiac resynchronization therapy and implantable defibrillator (CRT-D).Methods and resultsIn a retrospective multicentre Italian study, we enrolled 559 consecutive HF patients candidates to CRT-D, and we grouped them in three pre-specified risk classes: low (CHADS2/CHA2DS 2-VASc 1-2), moderate (CHADS2/CHA2DS 2-VASc 3-4), and high (CHADS2 5-6/CHA2DS 2-VASc 5-8). All patients underwent regular follow-up at implanting centres every 6 months; data collection was extended till the 72th month of follow-up. At a median FU of 30 months, 143 patients (25.4%) were hospitalized for HF and 110 (19.5%) died. Event-free survival analysis showed a significant difference according to baseline CHADS2 and CHA2DS 2-VASc scores (Log-Rank for HF P < 0.001 for CHADS2 and CHA2DS2-VASc; Log-Rank for combined end-point P = 0.001 for CHADS2, P < 0.001 for CHA2DS2-VASc). At multivariate analysis, independent predictors of endpoints were: previous atrial fibrillation (AF) or AF at implant, NYHA class, QRS duration and the CHA 2DS2-VASc score (for HF hospitalization P = 0.013; for the combined event, P = 0.007), while the CHADS2 score was not independently associated with either the end-points.ConclusionIn CRT-D patients, pre-implant CHA2DS2-VASc score is an independent predictor of major clinical events at 30-month follow-up. © 2013 The Author
Fattori prognostici di sopravvivenza a lunghissimo termine (9 anni) in pazienti affetti da cardiopatia ipocinetico-dilatativa e sottoposti a terapia di resincronizzazione elettrica cardiaca: il ruolo del genere femminile.
No full textManagement of refractory atrial fibrillation post surgical ablation
No full textOver the past two decades, invasive techniques to treat atrial fibrillation (AF) including catheter-based and surgical procedures have evolved along with our understanding of the pathophysiology of this arrhythmia. Surgical treatment of AF may be performed on patients undergoing cardiac surgery for other reasons (concomitant surgical ablation) or as a stand-alone procedure. Advances in technology and technique have made surgical intervention for AF more widespread. Despite improvements in outcome of both catheter-based and surgical treatment for AF, recurrence of atrial arrhythmias following initial invasive therapy may occur.Atrial arrhythmias may occur early or late in the post-operative course after surgical ablation. Early arrhythmias are generally treated with prompt electrical cardioversion with or without antiarrhythmic therapy and do not necessarily represent treatment failure. The mechanism of persistent or late occurring atrial arrhythmias is complex, and these arrhythmias may be resistant to antiarrhythmic drug therapy. The characterization and management of recurrent atrial arrhythmias following surgical ablation of AF are discussed below
Larger Interventricular Conduction Time Enhances Mechanical Response to Resynchronization Therapy
No full textBACKGROUND:
Previous studies have reported that the left ventricular (LV) pacing site is a major determinant of the hemodynamic response to cardiac resynchronization therapy (CRT). However, lead positioning in a lateral or posterolateral cardiac vein may not be optimal for every patient. The objective of this study was to assess the relationship between the right ventricular (RV)-to-LV conduction time and the systolic function during CRT on the basis of changes to LV pressure-volume loops.
METHODS:
Left ventricular pressure and volume data were determined using a conductance catheter during CRT device implantation in 10 patients. Four endocardial LV sites were systematically assessed at four atrioventricular delays. The RV-to-LV conduction time was measured as the time interval between spontaneous peak R waves, recorded through the RV lead and the LV catheter.
RESULTS:
The optimal pacing site varied among patients. However, the pacing site associated with the maximum RV-to-LV conduction time resulted in a stroke volume improvement comparable to the pacing site identified through individual hemodynamic optimization (41 ± 17 mL vs 44 ± 18 mL, P = 0.266). Moreover, the RV-to-LV conduction time recorded at each endocardial pacing site correlated positively with the increase in stroke volume (r = 0.537; P < 0.001), stroke work (r = 0.642; P < 0.001), and the pressure-derivative maximum (r = 0.646; P < 0.001) obtained with CRT.
CONCLUSIONS:
An optimal acute response to CRT can be obtained by positioning the LV lead at the site associated with the maximum RV-to-LV conduction time. A significant correlation appears to exist between RV-to-LV conduction time and the improvement in systolic function with CR
Correlations between NT-proBNP, outcome and haemodynamics in patients with septic shock
No full textAim The aim of this study was to determine the role of NT-proBNP in predicting the outcome of septic patients and to evaluate possible correlations between NT-ProBNP and haemodynamics in sepsis. Methods Forty consecutive patients with severe sepsis were prospectively evaluated. Patients were treated with the gold standard therapy for sepsis. NT-BNP levels, endotoxin activity (EA), SOFA score and SAPS II score, cardiac index (CI), mean arterial pressure (MAP) and pulmonary arterial pressure (PAP) were evaluated at admission and after 72 hours. Survival was evaluated at 28 days after admission. Results At 4-week follow-up, 22 patients had died (55%). Survival was not associated with age, gender, baseline EA and treatment, while it was associated with NT-proBNP levels at admission and after 72 hours. NT-proBNP > 1,000 pg/ml at 72 hours was a robust independent predictor of survival. The area under the curve (AUC) of NT-proBNP at admission was 0.73 and 0.99 after 72 hours. At 72 hours, AUC for SOFA score was 0.94, for SAPS II score 1, for EA 0.73. Levels of NT-proBNP > 1,000 pg/ml at 72 hours were associated with an adverse outcome (sensitivity 95.5%, specifi city 94.4%). NT-proBNP at 72 hours correlated with CI, MAP and PAP (P < 0.01, < 0.01,< 0.05 respectively). Conclusions Increased NT-proBNP levels at 72 hours could predict mortality at 28 days in patients with septic shock and are correlated with haemodynamics
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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