1,721,125 research outputs found
Exercise-induced pulmonary hypertension.
No full textExercise stress tests of the pulmonary circulation show promise for the detection of early or latent pulmonary vascular disease and may help us understand the clinical evolution and effects of treatments in patients with established disease. Exercise stresses the pulmonary circulation through increases in cardiac output and left atrial pressure. Recent studies have shown that exercise-induced increase in pulmonary artery pressure is associated with dyspnea-fatigue symptomatology, validating the notion of exercise-induced pulmonary hypertension. Exercise in established pulmonary hypertension has no diagnostic relevance, but may help in the understanding of changes in functional state and the effects of therapies.Journal ArticleSCOPUS: re.jinfo:eu-repo/semantics/publishe
Classification of Patients with Congenital Systemic-to-Pulmonary Shunts Associated with Pulmonary Hypertension: Current Status and Future Directions
No full textEnd points in pulmonary arterial hypertension: the way forward.
No full textPulmonary arterial hypertension is a rare disease of poor prognosis. Despite its rarity >1,000 patients have been randomised in placebo-controlled trials using novel therapies, including prostacyclin analogues, endothelin receptor antagonists and, most recently, phosphodiesterase 5 inhibitors. Nearly all of these trials have used exercise capacity, measured by the unencouraged 6-min walking distance, as the primary end point and a variety of other measurements as secondary end points. This approach has been productive, leading to the licensing of a number of effective treatments. Future clinical trials, however, will probably assess drug combinations, make comparisons between drugs and include less severely ill patients. It is, therefore, timely to examine the end points used. The authors discussed the various end points that have been used in the past and possible end points that might be used in the future. End points considered included measurements of: exercise capacity, haemodynamics, quality of life, imaging of the right heart and circulation, and chemical markers of pulmonary hypertension. Many of these show promise but will have to be used in parallel and compared with conventional end points such as the 6-min walking distance before their value can be demonstrated convincingly to the regulatory authorities
The right heart-pulmonary circulation unit. physiopathology
No full textThe most common cause of right heart failure is increased afterload caused by pulmonary hypertension. Right ventricular function adaptation to increased afterload is basically systolic, with secondary increase in dimensions and systemic congestion. Increased right ventricular dimensions and decreased ejection fraction are associated with a decreased survival in severe pulmonary hypertension. Targeted therapies titrated to reverse the right ventricular remodeling dimensions improve survival in severe pulmonary hypertension
Imaging the right heart: A challenging road map
No full textSCOPUS: sh.jFLWINinfo:eu-repo/semantics/publishe
EXERCISE STRESS ECHOCARDIOGRAPHY OF THE PULMONARY CIRCULATION: LIMITS OF NORMAL AND GENDER DIFFERENCES.
No full textEchocardiographic Prediction of Pre- versus Postcapillary Pulmonary Hypertension
No full textBackground: The differential diagnosis between pre- and postcapillary pulmonary hypertension (PH) is of major therapeutic relevance and thus requires optimal clinical probability assessment with echocardiography.
Methods: We prospectively analyzed 152 consecutive patients referred to a PH center over a 1-year period undergoing quasi-simultaneous (within 1 hour) echocardiography and right heart catheterization. Echocardiography was performed as usually recommended for the assessment of PH and left heart conditions. PH was defined as a mean pulmonary artery pressure ≥ 25 mm Hg. Postcapillary PH was diagnosed on the basis of a pulmonary capillary wedge pressure >15 mm Hg.
Results: Ten of 152 patients (7%) had no PH, 81 of 152 (53%) had precapillary PH, and 61 of 152 (40%) had postcapillary PH. The following five echocardiographic variables were found to predict precapillary PH: right heart chamber larger than the left (P = .0018), left ventricular eccentricity index > 1.2 (P = .0039), dilated inferior vena cava without inspiratory collapse (P = .0076), E/e' ratio ≤ 10 (P = .00001), and the right ventricle forming the heart apex (P = .0144). Beta coefficients from multiple logistic regression were significant for dilated inferior vena cava without inspiratory collapse (P = .0464) and E/e' ratio ≤ 10 (P = .0002). The score based on β coefficients, ranging from 3 to 34 points, resulted in optimal discrimination at >5, with a positive predictive value of 67.9% and a negative predictive value of 77.5% for precapillary PH.
Conclusion: Echocardiography enables a clinically satisfactory differential diagnosis between pre- and postcapillary PH
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
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