1,721,050 research outputs found
Current perspectives modern hemodynamic evaluation of the pulmonary circulation. Application to pulmonary arterial hypertension and embolic pulmonary hypertension.
No full textThe hemodynamic evaluation of the pulmonary circulation normally includes the measurements of mean pulmonary artery pressure and a calculation of pulmonary vascular resistance (PVR). The definition of PVR can be improved by the measurements of pulmonary vascular pressures at several levels of flow to derive a pressure-flow line, and the site of PVR can be identified by the analysis of pulmonary artery pressure decay curves after balloon occlusion. An analysis of the morphology of pulmonary artery pressure and flow waves informs about right ventricular (RV) hydraulic load. As pulmonary hypertension is clinically a right heart failure syndrome, it is important to measure the coupling of RV to pulmonary arterial function. This can be done using a single beat method with sampling and synchronization of instantaneous pulmonary artery flow and RV pressure to calculate a ratio of end-systolic to arterial elastances. The optimal value of this ratio is depressed in minimally symptomatic pulmonary arterial hypertension patients, indicating pending right heart failure.Journal ArticleReviewinfo:eu-repo/semantics/publishe
Classification of Patients with Congenital Systemic-to-Pulmonary Shunts Associated with Pulmonary Hypertension: Current Status and Future Directions
No full textPulmonary Hypertension in Heart Failure: Pathophysiology, Pathobiology, and Emerging Clinical Perspectives
No full textPulmonary hypertension is a common hemodynamic complication of heart failure. Interest in left-sided pulmonary hypertension has increased remarkably in recent years because its development and consequences for the right heart are now seen as mainstay abnormalities that begin in the early stages of the disease and bear unfavorable prognostic insights. However, some knowledge gaps limit our ability to influence this complex condition. Accordingly, attention is now focused on: 1) establishing a definitive consensus for a hemodynamic definition, perhaps incorporating exercise and fluid challenge; 2) implementing the limited data available on the pathobiology of lung capillaries and small arteries; 3) developing standard methods for assessing right ventricular function and, hopefully, its coupling to pulmonary circulation; and 4) searching for effective therapies that may benefit lung vessels and the remodeled right ventricle. The authors review the pathophysiology, pathobiology, and emerging clinical perspectives on pulmonary hypertension across the broad spectrum of heart failure stages.SCOPUS: re.jinfo:eu-repo/semantics/publishe
Componente dello Steering Committee Studio ALPHABET “A double-blind, randomised, placebo-controlled, European multicentre study to investigate the efficacy of beraprost sodium 20 μg tablet oral route on exercise capacity and morbi-mortality in children and adult patients with Pulmonary Arterial Hypertension (PAH)” RU55 100/1L03.
No full textImpact of pharmacologic interventions-treating endothelial dysfunction and group 2 pulmonary hypertension
No full textPulmonary hypertension (PH) secondary to left heart disease (LHD) is a largely underappreciated therapeutic target. Except for a specific focus on PH consequences in patients with advanced heart failure (HF) receiving a left ventricular assist device or candidates for heart transplant, prevention and treatment of initial subclinical forms of PH are not considered a priority in the management of this chronic disease population. Nonetheless, there is recent growing evidence supporting a clinical and prognostic role of PH in the elderly populations and in HF with preserved ejection fraction (pEF). Although the prevalence of PH in these populations still remains largely unknown, there is a large potential for effective pharmacological approaches that might impact the natural history of HFpEF by targeting earlier stages. However, pharmacological studies performed to date with traditional pulmonary vasodilators (i.e. prostanoids and endothelin receptor blockers) in cohorts with HF and left-sided PH have not been positive, primarily because of concomitant systemic hypotension and hepatic toxicity. The encouraging preliminary data with more selective well-tolerated pulmonary vasodilators, such as phosphodiesterase type 5 inhibitors and guanylate cyclase stimulators/activators, however, suggest the need for new targets of pulmonary microvascular dysfunction and for treating PH-LHD at both early and later stages of the disease process.SCOPUS: ar.jinfo:eu-repo/semantics/publishe
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
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