2,219 research outputs found
On finite groups acting on acyclic low-dimensional manifolds
We consider finite groups which admit a faithful, smooth action on an acyclic
manifold of dimension three, four or five (e.g. euclidean space). Our first
main result states that a finite group acting on an acyclic 3- or 4-manifold is
isomorphic to a subgroup of the orthogonal group O(3) or O(4), respectively.
The analogue remains open in dimension five (where it is not true for arbitrary
continuous actions, however). We prove that the only finite nonabelian simple
groups admitting a smooth action on an acyclic 5-manifold are the alternating
groups A_5 and A_6, and deduce from this a short list of finite groups, closely
related to the finite subgroups of SO(5), which are the candidates for
orientation-preserving actions on acyclic 5-manifolds.Comment: 15 pages; improved versio
TAPSE/PASP use in heart failure: Implementing the evidence for simplicity
Commentary to: "Assessment of right ventricular-arterial coupling by echocardiography in patients with heart failure with reduced to mid-range ejection fraction: impact on survival" by Rosa et al
Effects of empagliflozin on cardiorespiratory fitness and significant interaction of loop diuretics
The effects of empagliflozin on cardiorespiratory fitness in patients with type 2 diabetes mellitus (T2DM) and heart failure with reduced ejection fraction (HFrEF) are unknown. In this pilot study we determined the effects of empagliflozin 10 mg/d for 4 weeks on peak oxygen consumption (VO2 ) in 15 patients with T2DM and HFrEF. As an exploratory analysis, we assessed whether there was an interaction of the effects of empagliflozin on peak VO2 of loop diuretics. Empagliflozin reduced body weight (-1.7 kg; P = .031), but did not change peak VO2 (from 14.5 mL kg-1 min-1 [12.6-17.8] to 15.8 [12.5-17.4] mL kg-1 min-1 ; P = .95). However, patients using loop diuretics (N = 9) demonstrated an improvement, whereas those without loop diuretics (N = 6) experienced a decrease in peak VO2 (+0.9 [0.1-1.4] vs -0.9 [-2.1 to -0.3] mL kg-1 min-1 ; P = .001), and peak VO2 changes correlated with the baseline daily dose of diuretics (R = +0.83; P < .001). Empagliflozin did not improve peak VO2 in patients with T2DM and HFrEF. However, as a result of exploratory analysis, patients concomitantly treated with loop diuretics experienced a significant improvement in peak VO2
Cardiopulmonary Exercise Testing in the Clinical and Prognostic Assessment of Diastolic Heart Failure
ObjectivesThis study sought to define the relative prognostic value of cardiopulmonary exercise testing (CPET) variables in heart failure (HF) patients with preserved versus reduced systolic function.BackgroundCardiopulmonary exercise testing has an established role in the assessment of patients with systolic heart failure (SHF). Two variables, peak Vo2and, more recently, the Ve/Vco2slope, have been shown to be extremely valuable in risk stratification. However, data are lacking in terms of the prognostic value of CPET in patients with diastolic heart failure (DHF).MethodsA total of 409 HF patients underwent CPET. Patients were divided into three groups according to the following left ventricular ejection fraction (LVEF) cutoffs: ≥40%, ≥45%, and ≥50%. The CPET response and the ability of peak Vo2and the Ve/Vco2slope to predict total mortality and hospitalization were examined.ResultsAt univariate Cox regression analysis, both the peak Vo2and the Ve/Vco2slope were significant predictors in SHF and DHF. Multivariate analysis documented a similar prognostic power of Ve/Vco2slope and peak Vo2in all SHF groups. Conversely, in DHF patients, Ve/Vco2slope outnumbered peak Vo2, remaining the only predictor regardless of LVEF. In DHF, the area under the receiver operating characteristic curve for the Ve/Vco2slope identified a cutoff of 32.6 (74% sensitivity, 52% specificity), 33.1 (76% sensitivity, 62% specificity), and 33.3 (97% sensitivity, 40% specificity) for an LVEF cutoff of ≥40%, ≥45%, and ≥50%, respectively.ConclusionsThese results extend the clinical and prognostic applicability of CPET to DHF. An impairment in exercise ventilation rather than peak Vo2holds clinical and prognostic impact in this increasing subset of patients
Monitoring functional capacity in heart failure.
This document reflects the key points of a consensus meeting of the Heart Failure Association of European Society of Cardiology (ESC) held to provide an overview the role of physiological monitoring in the complex multimorbid heart failure (HF) patient. This article reviews assessments of the functional ability of patients with HF. The gold standard measurement of cardiovascular functional capacity is peak oxygen consumption obtained from a cardiopulmonary exercise test. The 6-min walk test provides an indirect measure of cardiovascular functional capacity. Muscular functional capacity is assessed using either a 1-repetition maximum test of the upper and lower body or other methods, such as handgrip measurement. The short physical performance battery may provide a helpful, indirect indication of muscular functional capacity
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