BACKGROUND Defibrillation threshold (DFT) testing at the time of implantable cardioverter defibrillator (ICD) implantation is widely used in clinical practice, but reliable data supporting its routine use are lacking. We undertook a meta-analysis to evaluate the efficacy of DFT testing compared to no DFT testing at the time of ICD implantation. METHODS We searched the MEDLINE and EMBASE datab...

The results of a systematic study of molecular properties by density functional theory (DFT) are presented and discussed. Equilibrium geometries, dipole moments, harmonic vibrational frequencies, and atomization energies were calculated for a set of 32 small neutral molecules by six different local and gradient-corrected DFT methods, and also by the ab initio methods Hartree-Fock, second-order ...

OBJECTIVES The purpose of this study was to prospectively investigate the influence of ventricular fibrillation (VF) durations of 5, 10 and 20 s on the defibrillation threshold (DFT) during implantable cardioverter-defibrillator (ICD) implantation. BACKGROUND Although the DFT using monophasic waveforms has been shown to increase with VF duration in humans, the effect of VF duration on defibri...

We study the effect of functional groups (CH3*4, OCH3, CH3, Cl, CN, F*4) on the electronic transport properties of 1,4-benzenediamine molecular junctions using the non-equilibrium Green function method. Exchange and correlation effects are included at various levels of theory, namely density functional theory (DFT), energy level-corrected DFT (DFT+Σ), Hartree-Fock and the many-body GW approxima...

AIMS Advanced cardiac disease, entailing more hypertrophy, fibrosis, scarring, dilatation and conduction delays, poses the question of whether defibrillation thresholds (DFTs) increase as left ventricular ejection fraction (LVEF) decreases. This question has been approached indirectly or insufficiently in previous studies. In this study we add and expand on our previous work, stratifying DFT fo...

This summary of the doctoral thesis [8] is created to emphasize the close connection of the proposed spectral analysis method with the Discrete Fourier Transform (DFT), the most extensively studied and frequently used approach in the history of signal processing. It is shown that in a typical application case, where uniform data readings are transformed to the same number of uniformly spaced fr...

Iron oxides are materials of wide interest that exhibit diverse electric, magnetic, optical, and catalytic properties; therefore, many studies to gain complete understanding of their polytypic phase boundary have been pursued. However, firstprinciples investigations of iron oxides using conventional density functional theory (DFT) calculations often yield a gross error due to the strong electro...

The electronic structure relevant to low spin (LS)↔high spin (HS) transitions in Fe(II) coordination compounds with a FeN6 core are studied. The selected [Fe(tz)6]2+ (1) (tz = 1H-tetrazole), [Fe(bipy)3]2+ (2) (bipy = 2,2'-bipyridine), and [Fe(terpy)2]2+ (3) (terpy = 2,2':6',2″-terpyridine) complexes have been actively studied experimentally, and with their respective mono-, bi-, and tridentate ...

Multi-reference effects can be covered by density functional theory (DFT) either implicitly via the exchange-correlation functional or explicitly via the form of the Kohn-Sham wave function. With the help of the exchange hole it is shown that the self-interaction error of the exchange functional will mimic long-range electron correlation effects if restricted Kohn-Sham theory is used. Functiona...

BACKGROUND Identification of individual factors associated with high defibrillation threshold (DFT) seems to be of high clinical importance. Impedance cardiography (ICG) may be used for non-invasive evaluation of the haemodynamic status. Whether ICG parameters may improve identification of patients with high DFT has not yet been examined. AIM To evaluate clinical risk factors of high DFT incl...