1,721,113 research outputs found
Epidemiology and prognosis of heart failure
Heart failure (HF) is a major and growing health problem in western communities. Recent data indicate that more than 50% of patients with the clinical syndrome of HF have a preserved left ventricular ejection fraction (HF with preserved ejection fraction, HFpEF). In contrast to the calculated expectations, the observed incidence of HF is rising. Despite the fact that the relative proportion of patients with preserved left ventricular function is also increasing, other factors, such as ageing of the population and the concomitant change of compound risk factors may also contribute to the actual rise in the incidence of HF. Patients with HF suffer from reduced exercise capacity, impaired quality of life and also from recurrent hospitalization due to HF. Over the past decades, an increase of recurrent HF events has been documented. In contrast to earlier reports in which HFpEF was considered to be more benign than HF with reduced ejection fraction (HFrEF), recent data suggest that once hospitalized for HF, patients with HFpEF and those with HFrEF have a comparable prognosis in terms of morbidity and mortality. Despite increasing clinical and economic relevance, no treatment has yet been shown to convincingly reduce mortality in HFpEF. In contrast, strategies for improving survival have now been established for HFrEF. The problem of HF will continue to be major challenge for the healthcare systems in western communities; therefore, consolidated clinical research is necessary to further improve therapeutic strategies for HFrEF and to generally establish treatment options for HFpEF
Diastolic Heart Failure: Diagnosis, Therapy and Impact of Exercise Training
Heart failure is a major health problem m the community Nearly half the patients suffering from signs and symptoms of heart failure have preserved systolic function and evidence of diastolic dysfunction. Comparable to systolic heart failure, patients with diastolic heart failure are characterised by high morbidity and mortality. Despite the urgent need of therapeutic strategies no evidence-based therapy is established in this condition. Exercise training, as a therapeutic approach, can prevent the age dependent occurrence of diastolic dysfunction. Moreover, there is little published evidence that exercise training may improve clinical outcome in patients with diastolic heart failure. but randomised trials using sufficient endpoints are lacking. Whether exercise training improves exercise capacity quality of life and diastolic function are objectives of the prospective, randomised. controlled Ex-DHF-P study. The preliminary results are promising, but need to be confirmed in a larger trial which also has to investigate the effects of exercise training on prognosis in patients with diastolic heart failure
Exercise training in heart failure
In patients with chronic but stable heart failure (HF) exercise training is a recommended and widely accepted adjunct to an evidence-based management involving pharmacological and non-pharmacological therapies. Various pathophysiological mechanisms, such as central hemodynamics, vasculature, ventilation, skeletal muscle function as well as neurohormonal activation and inflammation are responsible for exercise intolerance described in HF patients. There is sufficient and growing evidence that exercise training in HF with reduced (HFrEF) and with preserved ejection fraction (HFpEF) is effective in improving exercise capacity, HF symptoms and quality of life. The positive effects of exercise training in HF are mediated by an improvement of central hemodynamics, endothelial function, inflammatory markers, neurohumoral activation, as well as skeletal muscle structure and function. In contrast to convincing data from a large meta-analysis, the large HF-ACTION study (Heart Failure-A Controlled Trial Investigating Outcomes of exercise TraiNing) only demonstrated a modest improvement of all cause mortality and hospitalizations in HFrEF. Outcome data in HFpEF are lacking. Whether interval training incorporating variable and higher intensities or the addition of resistance exercise to a standard aerobic prescription is superior in improving clinical status of HF patients is currently being examined. Despite increasing validation of the potential of exercise training in chronic HF, challenges remain in the routine therapeutic application, including interdisciplinary management, financing of long-term exercise programs and the need to improve short-term and long-term adherence to exercise training
Diastolic Heart Failure: Diagnosis, Therapy and Impact of Exercise Training
Heart failure is a major health problem m the community Nearly half the patients suffering from signs and symptoms of heart failure have preserved systolic function and evidence of diastolic dysfunction. Comparable to systolic heart failure, patients with diastolic heart failure are characterised by high morbidity and mortality. Despite the urgent need of therapeutic strategies no evidence-based therapy is established in this condition. Exercise training, as a therapeutic approach, can prevent the age dependent occurrence of diastolic dysfunction. Moreover, there is little published evidence that exercise training may improve clinical outcome in patients with diastolic heart failure. but randomised trials using sufficient endpoints are lacking. Whether exercise training improves exercise capacity quality of life and diastolic function are objectives of the prospective, randomised. controlled Ex-DHF-P study. The preliminary results are promising, but need to be confirmed in a larger trial which also has to investigate the effects of exercise training on prognosis in patients with diastolic heart failure
Exercise training in heart failure
Exercise training in patients with chronic stable heart failure (HF) is a recommended and broadly accepted treatment strategy that is an integral part of an evidence-based management involving pharmacological and non-pharmacological therapies. There is ample scientific evidence that exercise training in HF with reduced (HFrEF) and with preserved ejection fraction (HFpEF) improves exercise capacity, HF symptoms and quality of life. This is due to an improvement of central hemodynamics, endothelial function, neurohumoral activation, skeletal muscle structure and function as well as a decrease in inflammatory markers. The largest randomized, controlled HF-ACTION study (Heart Failure-A Controlled Trial Investigating Outcomes of exercise TraiNing) demonstrated that exercise training results in a modest improvement of all-cause mortality and hospitalizations in HFrEF, depending on adequate compliance. Outcome data in HFpEF are lacking. Besides compliance, efficacy of exercise training is dependent on the intensity and type of exercise. Resistance and high intensity endurance training in addition to a standard aerobic exercise seem to be superior in improving the clinical status of HF patients. In the future, individualized exercise programs will help to improve long-term adherence to exercise training
Going Beyond Counting First Authors in Author Co-citation Analysis
The 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
“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
We 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
- …
