62 research outputs found

    Dobutamine Echocardiography for Assessment of Viability in the Current Era

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    Purpose of review Studies from the 1990s and early 2000s documented the utility of dobutamine echocardiography for the prediction of functional recovery and prognosis with revascularization. The results of The Surgical Treatment of Ischemic Heart Failure (STICH) trial called into question the value of viability assessment using dobutamine echocardiography. The purpose of this review is to re-examine the literature on dobutamine echocardiography, put into context the STICH results, and provide insight into the current role of dobutamine echocardiography viability testing. Recent findings In contrast to the results of previous nonrandomized trials, the STICH trial showed that patients with viability defined by nuclear perfusion imaging or dobutamine echocardiography did not have improved survival with CABG compared with optimal medical therapy. Viability by dobutamine echocardiography was defined as the presence of contractile reserve in at least five segments with baseline dysfunction. The results of dobutamine echocardiography studies published before and after initiation of the STICH trial suggest that the definition of viability utilized in that trial may be suboptimal for assessment of improvement in global function and prognosis in patients undergoing revascularization. Assessment of global contractile reserve using wall motion score (WMS) or ejection fraction may be superior to utilization of a binary definition of viability confined to assessment of contractile reserve in a fixed number of segments because these indices provide information on both the magnitude and extent of contractile reserve of the entire left ventricle (LV). Summary Assessment of WMS or ejection fraction with dobutamine echocardiography may be the optimal means of evaluating the impact of viability on prognosis. Video abstract http://links.lww.com/HCO/A5

    Computational modelling with uncertainty of frequent users of e-commerce in Spain using an age-group dynamic nonlinear model with varying size population

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    [EN] Electronic commerce (EC) has numerous advantages. It allows saving time when we purchase an item, offers the possibility of review without depending on the schedules of traditional stores, access to a wider variety and quantity of articles, in many cases, with lower prices, etc. Based upon mathematical epidemiology tenets strongly related to social behavior able to describe the influence of peers, in this paper we propose an age-group dynamic model with population varying size based on a system of difference equations to study the evolution of the frequent users of EC over time in Spain. Using data from surveys retrieved from the Spanish National Statistics Institute, we use and design computational algorithms to perform a probabilistic estimation of the model parameters that allow the model output to capture the data uncertainty. Then, we will be able to perform a precise prediction with uncertainty.This work has been partially supported by the Ministerio de Economia y Competitividad grant MTM2017-89664-P and by the European Union through the Operational Program of the European Regional Development Fund (ERDF)/European Social Fund (ESF) of the Valencian Community 2014-2020, grants GJIDI/2018/A/009 and GJIDI/2018/A/010.Burgos-Simon, C.; Cortés, J.; Martínez-Rodríguez, D.; Villanueva Micó, RJ. (2019). Computational modelling with uncertainty of frequent users of e-commerce in Spain using an age-group dynamic nonlinear model with varying size population. Advances in Complex Systems. 22(4):1950009-1-1950009-17. https://doi.org/10.1142/S0219525919500097S1950009-11950009-17224Bettencourt, L. (1997). Customer voluntary performance: Customers as partners in service delivery. Journal of Retailing, 73(3), 383-406. doi:10.1016/s0022-4359(97)90024-5Brauer, F., & Castillo-Chávez, C. (2001). Mathematical Models in Population Biology and Epidemiology. Texts in Applied Mathematics. doi:10.1007/978-1-4757-3516-1Cortés, J.-C., Lombana, I.-C., & Villanueva, R.-J. (2010). Age-structured mathematical modeling approach to short-term diffusion of electronic commerce in Spain. Mathematical and Computer Modelling, 52(7-8), 1045-1051. doi:10.1016/j.mcm.2010.02.030Hethcote, H. W. (2000). The Mathematics of Infectious Diseases. SIAM Review, 42(4), 599-653. doi:10.1137/s0036144500371907Yanhui, L., & Siming, Z. (2007). Competitive dynamics of e-commerce web sites. Applied Mathematical Modelling, 31(5), 912-919. doi:10.1016/j.apm.2006.03.029Mahajan, V., Muller, E., & Bass, F. M. (1991). New Product Diffusion Models in Marketing: A Review and Directions for Research. Diffusion of Technologies and Social Behavior, 125-177. doi:10.1007/978-3-662-02700-4_6Turban, E., Outland, J., King, D., Lee, J. K., Liang, T.-P., & Turban, D. C. (2018). Electronic Commerce 2018. Springer Texts in Business and Economics. doi:10.1007/978-3-319-58715-

    Mitral Annular Plane Systolic Excursion: An Early Marker of Mortality in Severe COVID-19 Infection

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    Respiratory failure is a major cause of mortality among hospitalized patients with COVID-19. Previous studies have shown that right ventricular (RV) dilation and reduced RV longitudinal strain are markers of poor outcome in this disease. COVID-19 can cause direct myocardial injury resulting in left ventricular (LV) systolic dysfunction and heart failure suggesting that assessment of LV function might also have prognostic value. Reduction of longitudinal systolic function assessed by mitral annular plane systolic excursion (MAPSE) is an early indicator of myocardial disease in various cardiac disorders. In this retrospective study, we investigated the prognostic value of MAPSE in patients admitted with respiratory failure related to COVID-19 infection

    Safety and feasibility of dopamine-atropine stress echocardiography

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    Background Dobutamine-atropine stress echocardiography (DSE) has lower sensitivity in patients with advanced liver disease (ALD) due to vasodilation. Hypothesis Dopamine-atropine stress echocardiography (DopSE) may be an alternative to DSE in ALD patients by improving the blood pressure response to stress. Methods The safety and tolerability of DSE and DopSE were compared in 10 volunteers. The safety, adverse effects, and efficacy of DopSE were then assessed in 105 patients, 98 of whom had ALD. Dopamine was infused in stepwise fashion from 5 µg/kg/min to a peak dose of 40 µg/kg/min. Atropine was given before and in early stages of dopamine infusion up to cumulative dose of 1.5 mg. The hemodynamic responses of 98 ALD patients were compared with 102 patients with ALD who underwent standard DSE. Results In normal volunteers, systolic BP increased more with DopSE compared to DSE (61 ± 19 mm Hg vs 39 ± 15 mm Hg, P = .008). In 105 patients who underwent DopSE, none had adverse effects that required early stress termination. In the groups with ALD, the systolic BP increase (38 ± 28 mm Hg vs 12 ± 27 mm Hg, P < .001) and peak rate pressure product (RPP) (22 861 ± 5289 vs 17 211 ± 3848, P = <.001) were both higher in those undergoing DopSE versus DSE. The sensitivity and specificity of DopSE were 45% and 88%, respectively for coronary disease (≥70% stenosis) in 37 patients who had angiography. Conclusions Dopamine-atropine stress echocardiography appears to be a safe stress modality and provides greater increases in RPP in patients with ALD compared to DSE

    Orthostatic headache and bilateral abducens palsy secondary to spontaneous intracranial hypotension

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    Spontaneous intracranial hypotension (SIH) is a well-documented syndrome characterized typically by a benign, self-limited course. Patients typically present with postural or exertional headaches that can be temporarily relieved by lying in a supine or recumbent position. A 35-year-old Caucasian male suffered orthostatic headache that developed to a bilateral abducens palsy. We ordered relative rest and the patient improved and completely recovered after 3 months. Although SIH is considered as a benign and self limited process it could also be associated with disabling complications. We should be aware of the possible complications and inform our patients. SIH can present with headache and bilateral abducens palsy even when the headache is improving

    Haemodynamic effects of the nitroxyl donor cimlanod (BMS-986231) in chronic heart failure: a randomized trial

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    Aims Nitroxyl provokes vasodilatation and inotropic and lusitropic effects in animals via post-translational modification of thiols. We aimed to compare effects of the nitroxyl donor cimlanod (BMS-986231) with those of nitroglycerin (NTG) or placebo on cardiac function in patients with chronic heart failure with reduced ejection fraction (HFrEF). Methods and results In a randomized, multicentre, double-blind, crossover trial, 45 patients with stable HFrEF were given a 5 h intravenous infusion of cimlanod, NTG, or placebo on separate days. Echocardiograms were done at the start and end of each infusion period and read in a core laboratory. The primary endpoint was stroke volume index derived from the left ventricular outflow tract at the end of each infusion period. Stroke volume index with placebo was 30 ± 7 mL/m2 and was lower with cimlanod (29 ± 9 mL/m2; P = 0.03) and NTG (28 ± 8 mL/m2; P = 0.02). Transmitral E-wave Doppler velocity on cimlanod or NTG was lower than on placebo and, consequently, E/e′ (P = 0.006) and E/A ratio (P = 0.003) were also lower. NTG had similar effects to cimlanod on these measurements. Blood pressure reduction was similar with cimlanod and NTG and greater than with placebo. Conclusion In patients with chronic HFrEF, the haemodynamic effects of cimlanod and NTG are similar. The effects of cimlanod may be explained by venodilatation and preload reduction without additional inotropic or lusitropic effects. Ongoing trials of cimlanod will further define its potential role in the treatment of heart failure

    Enhancing Wellbeing in Retirement: Addressing Negative Shocks

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    We consider how funded retirement arrangements intended for middle and upper income earners might be changed to enhance wellbeing in retirement. We briefly survey the history of these pension arrangements, which have led in recent years to increased vulnerability to investment and longevity risks, and the literature on wellbeing after retirement in the face of these risks. We then report on a survey of middle and upper income Australians, who are typical retirees with reasonable health insurance and defined contribution retirement funds. We investigate factors that affect subjective wellbeing and consumption, particularly following shocks created by a major financial loss or the occurrence of a serious illness or disability. As expected, we find a variety of factors, particularly lower relative and absolute wealth measures, are predictors of changes in consumption and lead to lower well-being. We also find evidence of mental annuitization amongst women particularly suggesting the need for reversionary annuities

    Formulating appropriate utility functions and personal financial plans

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    Without inflation protected pensions, people need decision making tools (financial calculators) to make informed decisions about savings and investment for retirement. For investment, they need a framework to trade off risk and return. This paper examines the assumptions underlying some of the common utility functions in the financial literature and suggests ways of making them more consistent with the behavioural and happiness literature. In particular, frictional costs are introduced to explain loss aversion. The results are illustrated in a way that could perhaps be presented to users of financial calculators to elicit their preferences and assist in making more coherent decisions
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