1,720,984 research outputs found
Advances in the diagnosis of acute aortic syndromes: Role of imaging techniques.
Aortic diseases include a wide range of pathological conditions: aortic aneurysms, pseudoaneurysms, acute aortic syndromes, atherosclerotic and inflammatory conditions, genetic diseases and congenital anomalies. Acute aortic syndromes have acute onset and may be life-threatening. They include aortic dissection, intramural haematoma, penetrating aortic ulcer and traumatic aortic injury. Pain is the common denominator to all acute aortic syndromes. Pain occurs regardless of age, gender and other associated clinical conditions. In this review, we deal with the main findings in the clinical setting and the most recent indications for diagnostic imaging, which are aimed to start an appropriate treatment and improve the short- and long-term prognosis of these patients.
© The Author(s) 2016
Evaluation of left atrial appendage function and thrombi in patients with atrial fibrillation: from transthoracic to real time 3D transesophageal echocardiography
The detection of embolic sources in patients with atrial fibrillation (AF) is important to guide anticoagulant therapy. Two-dimensional transesophageal echocardiography (TEE) is the gold standard to study left atrial appendage (LAA) anatomy and morphology, despite some false-positive diagnosis. We hypothesized that real time 3D TEE (RT3DTEE) is superior to 2DTEE in detecting and/or excluding LAA thrombi. We studied 93 patients with non-valvular AF (60 males, age = 67.1 ± 14.2 years) referred for electric cardioversion with transthoracic, 2DTEE and RT3DTEE. Before cardioversion, TTE allowed a confident measurement of emptying velocity of LAA (LAAeV) only in 59/93 patients (63%). On the contrary a good quality TEE LAAeV was obtained in all patients with 49/93 (53%) dysfunctional LAA (LAAeV < 40 cm/s). A subgroup of 5 patients (7.2% of the 69 effective cardioversion) presented a persistent dysfunction after cardioversion (with LAAeV values of <40 cm/s on the TEE post-CV). TEE allowed to observe a bilobed shape in 45 patients (48.4%) and three lobes in 22 patients (23.7%). In addition, besides to several additional findings, 2DTEE managed to detect thrombi with certainty in 8/93 patients (8.6%). In other 5 cases with diagnostic doubts for thrombi with 2DTEE (5/93 patients: 5.4%), the addition of the RT3DTEE mode allowed to discriminate with certainty the presence of just pectinate muscles in 4 patients RT3DTEE in patients with AF at risk of embolism is feasible, accurate and showed an additional diagnostic capability in the differential diagnosis of selected cases with suspected LAA thrombi
Fulminant Peripartum myocarditis associated with sudden cardiac death: a case report
Myocarditis is an inflammatory disease of myocardium, associated with nonischemic necrosis and degeneration of myocytes. Although the clinical course is rapid, myocarditis can lead to dilated cardiomyopathy with chambers dilatation and ventricular dysfunction. The pathophysiology of myocarditis in humans is not completely understood. There are several etiological agents implicated, mainly viral agents. The clinical presentation is extremely various, with nonspecific systemic symptoms until sudden death. The great variability of symptoms makes the diagnosis, therefore, extremely difficult. We report the case of a 40-year-old woman who developed, after childbirth, hyperthermia associated with neck and left arm pain; initially treated with acetaminophen, without any benefit, the young woman, after few days, died suddenly. The autopsy documented the presence of edematous lungs and enlarged and congested liver. The microbiological tests performed 4 days after death were negative. The heart was normal in shape and volume; a section of the left ventricle wall showed subendocardial discromic areas histologically characterized by multifocal perivascular and interstitial inflammatory infiltrates. These infiltrates consisted mainly of neutrophils with eosinophil component associated with myocyte necrosis and hemorrhagic interstitial infiltration
Focus on alirocumab: a PCSK9 antibody to treat hypercholesterolemia
Statin treatment represents the gold standard in the reduction of low-density lipoprotein cholesterol and cardiovascular risk. Although statin therapy is generally well tolerated, some patients fail to achieve the target level of low-density lipoprotein cholesterol or discontinue the treatment for the occurrence of adverse events. In recent years new lipid-modifying agents have been studied to overcome these limitations and to reduce low-density lipoprotein cholesterol plasma levels. Alirocumab is a fully human monoclonal antibody that inhibits proprotein convertase subtilisin/kexin type 9, thereby preventing its interaction with low density lipoprotein receptors. Several trials have been conducted in the last few years to evaluate long-term effects of this new molecule on low-density lipoprotein cholesterol levels and cardiovascular risk
[Vitamin D deficiency and cardiovascular diseases]
Vitamin D deficiency is a condition that affects a high percentage of individuals of all ages. Considerable attention has been paid recently to the possible role of deficiency of this vitamin in the development of several chronic diseases, including cardiovascular and metabolic diseases. In particular, vitamin D deficiency is associated with an increase in conditions such as obesity, insulin-resistance, hypertension, diabetes, and an increased risk of death from these pathologies. There is also a significant correlation with mortality for major cardiovascular events such as heart failure, myocardial infarction, sudden cardiac death, stroke, atrial fibrillation, and peripheral vascular disease. The pathophysiological mechanisms of these correlations are yet to be determined, but hyperactivity of the renin-angiotensin-aldosterone system seems to play a leading role. The role of therapy with vitamin D supplements in improving cardiovascular outcome in patients with low levels of vitamin D remains to be determined
Pulmonary hypertension in thyroid diseases.
The influence of thyroid hormones on cardiovascular system is well established. Thyroid diseases can effectively enhance the alteration on cardiovascular system by influencing chronotropic and inotropic actions of the heart; altering the strength and the speed of contraction, the speed of relaxation, the duration of the potential of action, and the duration of the refractory period and atrio-ventricular conduction time; modulating circulation and peripheral vascular beds. One of the more intriguing insights in the connection between thyroid diseases and cardiovascular alterations is related to the evaluation of the influence of thyroid hormones on pulmonary vascular beds. Literature reported several studies regarding the association between both hypothyroidism and hyperthyroidism and the occurrence of increased vascular pulmonary arterial pressure. Nevertheless, the pathogenetic mechanisms able to explain such relationship are not fully understood. Many doubts still persist in the comprehension of the mechanisms of pulmonary hypertension in thyroid diseases. The aim of this review was to provide possible explanation about the possible interaction between pulmonary vascular beds and thyroid function in order to evaluate the possibility of novel perspectives in the general management of patients suffering from thyroid and cardiovascular diseases
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
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