RESUMEN
Sudden cardiac death (SCD) can affect patients with ischemic or non-ischemic left ventricular dysfunction. Automatic implantable cardioverter-defibrillator (ICD) implantation is the most effective option for the treatment of malignant ventricular tachyarrhythmias; however, the procedure is burdened with known significant risks, even in the long term.In patients at high risk of SCD, either real or perceived, without a definite indication to ICD implantation, wearable cardioverter-defibrillators have been shown to offer effective temporary protection in different clinical settings, for patients with recent high-risk myocardial infarction with left ventricular dysfunction, even after myocardial revascularization procedures, heart failure with reduced ejection fraction, newly diagnosed dilated cardiomyopathy, ICD post-explant phase for infection, and bridge to cardiac transplantation.The purpose of this review is to describe the technical aspects and clinical results available in the literature on the use of wearable cardioverter-defibrillators, with particular reference to safety, efficacy, costs and patient selection, together with current and unconventional indications.The authors also report the first data related to their personal experience.
Asunto(s)
Muerte Súbita Cardíaca/prevención & control , Desfibriladores Implantables , Cardiopatías/terapia , Muerte Súbita Cardíaca/etiología , Cardiopatías/complicaciones , Cardiopatías/fisiopatología , Insuficiencia Cardíaca/terapia , Humanos , Infarto del Miocardio/terapia , Selección de Paciente , Taquicardia Ventricular/terapia , Disfunción Ventricular Izquierda/terapiaRESUMEN
Direct phonon excitation in a neutron time-of-flight single-crystal Laue diffraction experiment has been observed in a single crystal of NaCl. At room temperature both phonon emission and excitation leave characteristic features in the diffuse scattering and these are well reproduced using abinitio phonons from density functional theory (DFT). A measurement at 20â K illustrates the effect of thermal population of the phonons, leaving the features corresponding to phonon excitation and strongly suppressing the phonon annihilation. A recipe is given to compute these effects combining DFT results with the geometry of the neutron experiment.
RESUMEN
The accurate description of van der Waals forces within density functional theory is currently one of the most active areas of research in computational physics and chemistry. Here we report results on the structural and energetic properties of graphite and hexagonal boron nitride, two layered materials where interlayer binding is dominated by van der Waals forces. Results from several density functionals are reported, including the optimized Becke88 van der Waals (optB88-vdW) and the optimized PBE van der Waals (optPBE-vdW) (Klimes et al 2010 J. Phys.: Condens. Matter 22 022201) functionals. Where comparison to experiment and higher-level theory is possible, the results obtained from the two new van der Waals density functionals are in good agreement. An analysis of the physical nature of the interlayer binding in both graphite and hexagonal boron nitride is also reported.
Asunto(s)
Compuestos de Boro/química , Grafito/química , Interacciones Hidrofóbicas e Hidrofílicas , Teoría Cuántica , Absorción , Simulación por Computador , TermodinámicaRESUMEN
The prodromal stage of atherosclerotic lesions is already formed during human fetal development. The presence of infections during childhood may increase synergistically the progression of atherogenesis. After delivery, especially those children exposed to severe maternal hypercholesterolemia should be followed up for the onset and development of acute and chronic infections and be included in clinical and noninvasive examinations of vascular function.