1,720,958 research outputs found
Effects of Mild Ischemic Mitral Regurgitation on Ventricular Remodeling and Its Contribution to Congestive Heart Failure
No full textBackground: Although the prognostic impact of a moderate degree of ischemic mitral regurgitation (IMR) is well known, there are no data regarding the potential role of a mild degree of IMR. The aim of this study was to evaluate the impact of a mild degree (effective regurgitant orifice area < 20 mm 2) of IMR on left ventricular (LV) remodeling and heart failure (HF). Methods: A retrospective study was conducted in 35 patients with mild IMR that were propensity matched with 35 patients without IMR (controls). The population was evaluated between 3 and 6 months after first myocardial infarction and at 6 and 12 months, measuring LV volumes, ejection fraction, and the degree of mitral regurgitation. HF events requiring hospitalization were recorded. Results: The two groups were similar at baseline. During follow-up, patients with IMR showed significant increases in LV end-diastolic and end-systolic volumes and no change in ejection fractions, whereas controls did not show significant changes in volumes but did show increases in ejection fractions. Patients with IMR showed significantly higher end-systolic volumes at 6 months (P = .003) and 12 months (P = .007) and significantly higher end-diastolic volumes at 6 months (P = .048) and 12 months (P = .03) and lower ejection fractions at 6 months (P = .0001) and 12 months (P = .002) compared with controls. Patients with IMR experienced a significantly higher incidence of HF than controls (62% vs 23%, P = .001). At 6 months, in six patients mitral regurgitation degree changed from mild to moderate, and in one patient from mild to severe. Interestingly, 71.5% of patients who experienced increases in mitral regurgitation degree had no coronary revascularization (P = .04). Conclusions: Mild IMR affects the LV remodeling process, increases its degree over time, and determines a higher rate of HF. (J Am Soc Echocardiogr 2011;24:1376-82.
Valutazione e chiusura dei leak periprotesici: ruolo dell’ecocardiografia transesofagea tridimensionale in tempo reale
No full textPerivalvular leak following implant of aortic or mitral prosthetic valves or rings is a relatively common complication,
sometimes leading to significant clinical and hemodynamic consequences, such as severe valvular
insufficiency, heart failure and hemolysis. In these cases, a second surgical operation, which typically involves
the replacement of the dehiscent prosthesis, is the procedure of choice, but sometimes it cannot be performed.
The alternative to reoperation can be the percutaneous closure of the perivalvular leak guided by
transesophageal echocardiography before and during the closure procedure.
In this review, the current role of echocardiography in the study of perivalvular leaks, with particular reference
to guiding percutaneous transcatheter closure, is discussed. Also, the advantages and limitations of conventional
two-dimensional and real-time three-dimensional transesophageal echocardiography are compared
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
Intravascular Ultrasound-Guided Coronary Lithotripsy Treatment of In-Stent Restenosis in Saphenous Venous Graft
No full textAppropriate 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
Impact of functional tricuspid regurgitation on heart failure and death in patients with functional mitral regurgitation and left ventricular dysfunction
No full textThe prognostic role of tricuspid regurgitation (TR) associated with organic left-sided valvular heart disease is well known. However, no data are available regarding the prognostic value of functional TR (FTR) in patients with functional mitral regurgitation (FMR) and left ventricular (LV) dysfunction. The purpose of this study was to evaluate the prognostic role of FTR for occurrence of heart failure (HF) and mortality in patients with FMR. We enrolled 373 consecutive patients (mean age 68 11 years) with LV dysfunction and at least mild FMR and with or without FTR, both quantitated by echocardiography. The median follow-up was 32 months (range 1120 months); 132 (35.4) and 97 patients developed HF or died, respectively. The incidence of HF at 3 and 6 years was 36 2 and 55 4, respectively. Moderate to severe FTR [hazard ratio (HR) 1.4, 95 confidence interval (CI) 1.12.1, P 0.01) was an independent determinant of HF. The incidence of HF was 41 5, 46 7, 57 7, and 65 8 for patients without, and with mild, moderate, and severe FTR respectively (P 0.03). At 3 and 6 years the survival free of all-cause mortality was 77.5 2 and 60 3, respectively. Moderate to severe FTR (HR 1.6, 95 CI 1.22.1, P 0.01) was an independent determinant of overall mortality. At 6 years, survival free of all-cause mortality was 69 2.5, 67 2.1, 51 2.5, and 40 4.8 for patients without, and with mild, moderate, and severe FTR, respectively (P 0.004). Moderate or more FTR is independently associated with worse survival and a high incidence of HF episodes in patients with FMR
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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