1,720,956 research outputs found
Chapter 12: Prognostic Stratification and Importance of Follow-Up
No full textIn the last decades, long-term survival of patients affected by dilated cardiomyopathy (DCM) has been markedly improved. The main milestones, such as the early diagnosis and the systematic follow-up, the proper etiological characterization at the onset of the disease, and a multidisciplinary approach to the patients together with the optimal medical and device treatment and the rigorous tailored follow-up, accompanied these prognostic improvements. However, DCM still remains the most common cause of heart transplantation and one of the leading causes of cardiac death in the western world. Therefore, proper prognostic stratification and systematic follow-up are the cornerstones to optimize medical management and improve outcomes of patients with DCM
Historical Terminology, Classifications, and Present Definition of DCM.
No full textDilated cardiomyopathy (DCM) is defined by the presence of left ventricular (LV) dilation and systolic dysfunction in the absence of abnormal loading conditions or coronary artery disease sufficient to cause the LV systolic impairment. In the last years, advances in pathophysiology, pathology, biomarkers, genetics and molecular medicine, echocardiography, and cardiac magnetic resonance have allowed an evolution from an etiological to a morphological and then to a morphofunctional classification of the disease. Familial forms account for the 40% of cases, and thanks to the recent discoveries in the genetic field, clinicians have the opportunity but also the responsibility to provide an etiological diagnosis, stratify the risk, and treat patients with the best strategy available. Nowadays the etiologic characterization has dramatically improved so that it is possible to understand the etiologic basis of many so-called idiopathic heart muscle disease. A step toward a comprehensive DCM classification and an attempt to reconcile clinic with genetic in the complexity of the disease is genotype-phenotype correlation, with its prognostic implication in clinical practice. In this chapter will be discussed the historical evolution of DCM classification, and an overview of the main issues discussed in the next sections will be given
Chapter 3: Pathophysiology
Full text linkThe hallmark pathophysiologic feature of dilated cardiomyopathy is systolic dysfunction. Several pathogenetic mechanisms appear to be operative. These include increased hemodynamic overload, ventricular remodeling, excessive neurohumoral stimulation, abnormal myocyte calcium cycling, excessive or inadequate proliferation of the extracellular matrix, accelerated apoptosis, and genetic mutations. Although beneficial in the early stages of heart failure, these compensatory mechanisms eventually lead to a vicious cycle of worsening heart failure. Genetic causes account for 30–40% of DCM and involve genes that encode a heterogeneous group of molecules that participate in force generation, force transmission, sarcomere integrity, cytoskeletal and nuclear architecture, electrolyte homeostasis, mitochondrial function, and transcription. Additional research will improve our understanding of the complex and longitudinal molecular changes that lead from gene mutation to clinical expressio
Dilated Cardiomyopathy. From Genetics to Clinical Management
Full text linkThe current definition of dilated cardiomyopathy (DCM) is relatively simple: it is a heart muscle disease characterized by left ventricular (LV) or biventricular dilation and systolic dysfunction in the absence of either pressure or volume overload or coronary artery disease sufficient enough to explain the dysfunction. In the last 30 years, prognosis of patients with DCM has dramatically been improved with few
similarities in the history of cardiology and medicine. Typically, in the 1980s, the average survival rate was approximately 50% in a 5-year follow-up. Nowadays, at 10 years of follow-up, the survival/free from heart transplant rate is far beyond 85%, and the projection of this improvement is significantly better for those who have had DCM diagnosed in the late 2010s. This improvement in outcomes is fundamentally due to a better characterization of etiological factors, medical management for heart failure, and device treatment, like the implantable cardioverter defibrillator (ICD), for sudden cardiac death prevention. However, other milestones should be recognized for the improvement in the survival rate, namely, the early diagnosis due to familial and sport-related screening, which allow detection of DCM at a less severe stage, and the uninterrupted, active, and individualized long-term follow-up with continuous reevaluation of the disease and re-stratification of the risk
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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