54 research outputs found

    Connexive Conditional Logic. Part I

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    In this paper, first some propositional conditional logics based on Belnap and Dunn’s useful four-valued logic of first-degree entailment are introduced semantically, which are then turned into systems of weakly and unrestrictedly connexive conditional logic. The general frame semantics for these logics makes use of a set of allowable (or admissible) extension/antiextension pairs. Next, sound and complete tableau calculi for these logics are presented. Moreover, an expansion of the basic conditional connexive logics by a constructive implication is considered, which gives an opportunity to discuss recent related work, motivated by the combination of indicative and counterfactual conditionals. Tableau calculi for the basic constructive connexive conditional logics are defined and shown to be sound and complete with respect to their semantics. This semantics has to ensure a persistence property with respect to the preorder that is used to interpret the constructive implication

    Left Atrial Pressure as a Predictor of Success in Catheter Ablation of Atrial Fibrillation in a Real-Life Cohort

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    Aims: The clinical role of the left atrial (LA) hypertension in patients with atrial fibrillation (AF) and its role as predictor in those undergoing pulmonary vein (PV) isolation is still unknown. The aim of the present study was to analyze the role of LA pressure in patients with nonvalvular AF who underwent PV isolation and its implication for AF catheter ablation. Methods: Consecutive patients with drug resistant AF who underwent PV isolation at San Maurizio Regional Hospital of Bolzano (Italy) as index procedure were included in this analysis. Results: A total of 132 consecutive patients (97 males, 73%; mean age 58.0 ± 13.2 years) were included in the analysis. Eleven patients (8%) underwent radiofrequency ablation and 121 (92%) cryoballoon ablation. Higher LA pressures were found in 54 patients (40.9%). At a mean follow up of 14.3 ± 8.2 months (median 12 months), the success rate without antiarrhythmic therapy was 65.9% (87/132; considering the blanking period). Female gender and continuous mean LA pressure were significantly associated with AF recurrence and remained significant on multivariable Cox analysis (respectively, HR 1.845, 1.00–3.40, p = 0.05 and HR 1.066, 1.002–1.134, p = 0.04). We identified a LA mean pressure of >15 mmHg as ideal cutoff and constructed a model to predict AF recurrence which fitted with a concordance index (C-index) of 0.65 (95% CI 0.56–0.75), logrank score p = 0.003

    Philosophy of Science in Germany, 1992-2012: Survey-Based Overview and Quantitative Analysis

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    An overview of the German philosophy of science community is given for the years 1992-2012, based on a survey in which 159 philosophers of science in Germany participated. To this end, the institutional background of the German philosophy of science community is examined in terms of journals, centers, and associations. Furthermore, a qualitative description and a quantitative analysis of our survey results are presented. Quantitative estimates are given for: (a) academic positions, (b) research foci, (c) philosophers' of science most important publications, and (d) externally funded projects, where for (c) all survey participants had indicated their five most important publications in philosophy of science. In addition, the survey results for (a)-(c) are also qualitatively described, as they are interesting in their own right. With respect to (a), we estimated the gender distribution among academic positions. Concerning (c), we quantified philosophers' of science preference for (i) journals and publishers, (ii) publication format, (iii) language, and (iv) coauthorship for their most important publications. With regard to research projects, we determined their (i) prevalence, (ii) length, and (iii) trend (an increase in number?) as well as their most frequent (iv) research foci and (v) funding organizations. We also distinguished between German-based and non-German-based journals, publishers, and funding institutions, making it thereby possible to evaluate the involvement of the German philosophy of science community in the international research landscape. Finally, we discuss some implications of our findings

    Nutritional status in tricuspid regurgitation: implications of transcatheter repair

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    Aims To characterize the prevalence and clinical relevance of malnutrition in patients undergoing transcatheter tricuspid valve edge-to-edge repair (TTVR). Methods and results Overall, 86 consecutive patients (mean age 78 ± 7 years) with moderate-to-severe tricuspid regurgitation (TR) at prohibitive surgical risk were analysed. Mini Nutritional Assessment (MNA), quality of life assessment, 6-min walk test distance and laboratory analyses were performed before and 1 month after TTVR. A total of 43 patients (50%) underwent concomitant transcatheter mitral valve repair. According to MNA, 81 patients (94%) were malnourished or at risk of malnutrition before TTVR. Following TTVR, MNA improved in 64 patients (74%). As compared to patients without MNA improvement, patients with increased MNA score had greater reductions in TR [regurgitation volume −17.0 (interquartile range, IQR −25.0; −7.0) mL vs. −26.4 (IQR −40.3; −14.5) mL, P < 0.001] and inferior vena cava diameter. Only patients with increased MNA score displayed a decrease in N-terminal pro-brain natriuretic peptide levels [−320 (IQR −1294; 105) pg/mL vs. +708 (IQR −342; 2708) pg/mL, P = 0.009], improvements in cholinesterase levels (0.0 ± 11.9 μmoL/L vs. +10.9 ± 16.7 μmoL/L, P < 0.001) and renal function during follow-up. Beneficial effects on quality of life scores and 6-min walk test distance following TTVR were observed exclusively in patients with improvement in MNA. During a median follow-up of 6 months, patients with worsened MNA had an increased risk of death and rehospitalization for heart failure. Conclusion Nutritional impairment is common and of prognostic importance in patients undergoing TTVR. Hepatorenal function modestly improves after successful TTVR. Further study of extracardiac implications of TR-associated right heart failure is warranted to improve care in this vulnerable patient population

    Cardiac output states in patients with severe functional tricuspid regurgitation: impact on treatment success and prognosis

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    Aims To investigate whether there is evidence for distinct cardiac output (CO) based phenotypes in patients with chronic right heart failure associated with severe tricuspid regurgitation (TR) and to characterize their impact on TR treatment and outcome. Methods and results A total of 132 patients underwent isolated transcatheter tricuspid valve repair (TTVR) for functional TR at two centres. Patients were clustered according to k-means clustering into low [cardiac index (CI)  2.6 L/min/m2) clusters. All-cause mortality and clinical characteristics during follow-up were compared among different CO clusters. Mortality rates were highest for patients in a low (24%) and high CO state (42%, log-rank P < 0.001). High CO state patients were characterized by larger inferior vena cava diameters (P = 0.003), reduced liver function, higher incidence of ascites (P = 0.006) and markedly reduced systemic vascular resistance (P < 0.001) as compared to TTVR patients in other CO states. Despite comparable procedural success rates, the extent of changes in right atrial pressures (P = 0.01) and right ventricular dimensions (P < 0.001) per decrease in regurgitant volume following TTVR was less pronounced in high CO state patients as compared to other CO states. Successful TTVR was associated with the smallest prognostic benefit among low and high CO state patients. Conclusions Patients with chronic right heart failure and severe TR display distinct CO states. The high CO state is characterized by advanced congestive hepatopathy, a substantial decrease in peripheral vascular tone, a lack of response of central venous pressures to TR reduction, and worse prognosis. These data are relevant to the pathophysiological understanding and management of this important clinical syndrome. Graphical Abstract Proposed mechanism of hypercirculatory tricuspid regurgitation. Tricuspid regurgitation related backward failure causes liver congestion and dysfunction with portal hypertension and reduced washout of vasoactive substances. Consequent splanchnic and peripheral vasodilatation alongside with reduced renal blood flow results in renin–angiotensin–aldosterone system (RAAS) activation and sympathetic overactivation. The sympathetic drive and volume retention lead to further capacitance depletion and volume overload, eventually resulting in a high cardiac output state, with limited preload reduction and prognostic benefit following transcatheter tricuspid valve repair. The alterations in the graph should be interpreted as simultaneous interaction rather than a timeline. Continuous lines indicate findings in the present study. Dashed lines express currently accepted mechanistical considerations. AP, alkaline phosphatase; γGT, gamma-glutamyl-transferase; RA, right atrium; RV, right ventricle
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