1,090 research outputs found

    The Prognostic Value of Myocardial Deformation in Patients with Congenital Aortic Stenosis

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    Aims: To assess the prognostic value of left ventricular (LV) global longitudinal strain (GLS) and global longitudinal early diastolic strain rate (GLSre) with regard to cardiovascular events, as congenital aortic stenosis (AoS) is associated with significant mortality and morbidity but predictors for clinical outcome are scarce. Strain analysis provides a robust and reproducible method for early detection of LV dysfunction, which might be of prognostic value. Methods: This prospective study, included clinically stable patients with congenital AoS between 2011– 2013. LV GLS and GLSre was performed in the apical 4, 3 and 2-chamber views using Tomtec software. The end-point was a composite of death, heart failure, hospitalization, arrhythmia, thrombo-embolic events and re-inter-vention. Results: In total 138 patients were included (33[26–43] years, 86(62%) male), NYHA class I: 134(97%). Mean LV GLS was –15.3 ± 3.2%, GLSre 0.66 ± 0.18 s–1. Both correlated with NT-proBNP, LV volumes and ejection fraction (strongest LV GLS with LV EF: r –0.539, p &lt; 0.001, strongest LV GLSre with age: r –0.376, p &lt; 0.001). During median follow-up of 5.9[5.5–6.2] years, the endpoint occurred in 53(38%) patients: 4 patients died, 9 developed heart failure, 22 arrhythmias, 8 thrombo-embolic events and 35 re-interventions. Both LV GLS (stan-dardized HR (sHR 0.62(95%CI 0.47–0.81) and GLSre (sHR 0.62(95%CI 0.47–0.83) were associated with the end-point. Additional multivariable analysis showed that both GLS and GLSre were associated independent of left atrial volume, NT-proBNP and prior re-interventions. Conclusion: Left ventricular GLS and GLSre are reduced in adult patients with congenital AoS. Both markers are associated with adverse cardiac events and have clear clinical relevance.</p

    Personalized immunosuppression in elderly renal transplant recipients

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    The number of elderly people has increased considerably over the last decades, due to a rising life expectancy and ageing populations. As a result, an increased number of elderly with end-stage-renal-disease are diagnosed, for which the preferred treatment is renal transplantation. Over the past years the awareness of the elderly as a specific patient population has grown, which increases the importance of research in this group.Elderly patients often receive kidneys from elderly donors while younger donor kidneys are preferentially reserved for younger recipients. Although the rate of acute rejection after transplantation is lower in the elderly, these rejections may lead to graft loss more frequently, as kidneys from elderly donors have marginal reserve capacity. To prevent acute rejection, immunosuppressive therapy is needed. On the other hand, elderly patients have a higher risk to die from infectious complications, and thus less immunosuppression would be preferable.Immunosuppressive treatm

    Considering life and death:a qualitative vignette study among farm animal veterinarians in the Netherlands on considerations in end-of-life decision-making

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    Farm animal veterinarians are frequently involved in animals’ end-of-life (EoL) situations. Existing literature found that the decision-making process to end an animal’s life can be experienced as complex and stressful by veterinarians. The complexity of the process may find its origin in the multiple medical and non-medical aspects that veterinarians consider coming to their decision. Although research provides insight into what considerations are at stake, the literature does not provide information on how these aspects affect the decision-making process. This study explores how different considerations affect the decision-making process of farm animal veterinarians in EoL situations. Semi-structured interviews were conducted with nineteen farm animal veterinarians in the Netherlands. During the interviews, case scenarios in the form of vignettes were used to identify and explore the considerations that play a role for these veterinarians in EoL decision-making. Based on the analysis of the interview data, we discovered that farm animal veterinarians consider EoL situations using one of three identified frames: function, prospect, and duty. These frames illustrate one’s perspective on the interplay of medical and non-medical aspects. Whereas veterinarians for whom the function frame is dominant focus on the human-centred function that an animal fulfils, veterinarians for whom the prospect frame is dominant focus on an animal’s prospects based on the animal’s living conditions and the influence of the owner. Veterinarians for whom the duty frame is dominant focus on the owner’s legal position towards the animal, illustrating a clear distinction between the veterinarian’s professional duties towards the animal and the duty of care of the animal owner. As such, the key contributions of this study are the discovery of the importance of the interplay between considerations in EoL decision-making and the frame-specific approach of veterinarians. The identified frames may relate to the coping strategies of veterinarians dealing with the complexity of EoL situations.</p

    A Weakly nonlinear theory for spiral density waves excited by accretion disc turbulence

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    We develop an analytic theory to describe spiral density waves propagating in a shearing disc in the weakly nonlinear regime. Such waves are generically found to be excited in simulations of turbulent accretion disks, in particular if said turbulence arises from the magneto-rotational instability (MRI). We derive a modified Burgers equation governing their dynamics, which includes the effects of nonlinear steepening, dispersion, and a bulk viscosity to support shocks. We solve this equation approximately to obtain nonlinear sawtooth solutions that are asymptotically valid at late times. In this limit, the presence of shocks is found to cause the wave amplitude to decrease with time as 1/t^2. The validity of the analytic description is confirmed by direct numerical solution of the full nonlinear equations of motion. The asymptotic forms of the wave profiles of the state variables are also found to occur in MRI simulations indicating that dissipation due to shocks plays a significant role apart from any effects arising from direct coupling to the turbulence

    Qualitative grading of aortic regurgitation: a pilot study comparing CMR 4D flow and echocardiography.

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    Over the past 10 years there has been intense research in the development of volumetric visualization of intracardiac flow by cardiac magnetic resonance (CMR).This volumetric time resolved technique called CMR 4D flow imaging has several advantages over standard CMR. It offers anatomical, functional and flow information in a single free-breathing, ten-minute acquisition. However, the data obtained is large and its processing requires dedicated software. We evaluated a cloud-based application package that combines volumetric data correction and visualization of CMR 4D flow data, and assessed its accuracy for the detection and grading of aortic valve regurgitation using transthoracic echocardiography as reference. Between June 2014 and January 2015, patients planned for clinical CMR were consecutively approached to undergo the supplementary CMR 4D flow acquisition. Fifty four patients(median age 39 years, 32 males) were included. Detection and grading of the aortic valve regurgitation using CMR4D flow imaging were evaluated against transthoracic echocardiography. The agreement between 4D flow CMR and transthoracic echocardiography for grading of aortic valve regurgitation was good (j = 0.73). To identify relevant,more than mild aortic valve regurgitation, CMR 4D flow imaging had a sensitivity of 100 % and specificity of 98 %. Aortic regurgitation can be well visualized, in a similar manner as transthoracic echocardiography, when using CMR 4D flow imaging

    Left atrial deformation analysis in patients with corrected tetralogy of fallot by 3D speckle-tracking echocardiography (from the MAGYAR-path study)

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    Background: Three-dimensional (3D) echocardiography coupled with speckle-tracking echocardiographic (STE) capability is a novel methodology which has been demontrated to be useful for the assessment of left atrial (LA) volumes and functional properties. There is increased scientific interest on myocardial deformation analysis in adult patients with corrected tetralogy of Fallot (cTOF). Objectives: To compare LA volumes, volume-based functional properties and strain parameters between cTOF patients and age- and gender-matched healthy controls. Methods: The study population consisted of 19 consecutive adult patients with cTOF in sinus rhythm nursing at the University of Szeged, Hungary (mean age: 37.9 ± 11.3 years, 8 men, who had repair at the age of 4.1 ± 2.5 years). They all had undergone standard transthoracic two-dimensional Doppler echocardiographic study extended with 3DSTE. Their results were compared to 23 age- and gender-matched healthy controls (mean age: 39.2 ± 10.6 years, 14 men). Results: Increased LA volumes and reduced LA emptying fractions respecting cardiac cycle could be demonstrated in cTOF patients compared to controls. LA stroke volumes featuring all LA functions showed no differences between the 2 groups examined. LA global and mean segmental uni- and multidirectional peak strains featuring LA reservoir function were found to be diminished in adult patients with cTOF as compared to controls. Similarly to peak strains reduced global and mean segmental LA strains at atrial contraction characterizing atrial booster pump function could be demonstrated in cTOF patients as compared to controls. Conclusions: Significant deterioration of all LA functions could be demonstrated in adult patients with cTOF late after repair
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