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Biomedical subjects

A V Davidenko

Publications and source records attributed to A V Davidenko.

10 recordsLinked to original sources
PubMed1985

[Method of enhancing the diagnostic information value of the atrial vectorcardiogram].

An automated differentiation of the P loop from other VCG loops, its 20-fold magnification, visualization, and computation of its major spatial and projection parameters have been made possible, giving precise information on its configuration, duration, the direction of recording, as well as relative positions and directions of its instantaneous vectors. Digital computerization of the traces has produced different vector and scale characteristics of the spatial Pxyz loop.

Adult↗
PubMed1984

[Spatial characteristics of the P loop in normal subjects and in patients with an enlarged right atrium].

The studies performed have shown that: 1) using automatic reproduction of 10-20-fold magnified images of P-loop it is possible to learn its configuration, duration, recording direction, position and orientation of its moment vectors; 2) using digital computer list output of curves it is possible to determine numerical values of PXYZ-loop parameters and its vector and scalar characteristics; 3) for the diagnosis of right atrial dilatation (RAD) the assessment of vector values is more important than their orientation by azimuth and elevation angles; 4) the increase beyond normal (M + 2 sigma) of space vector values of PXYZ-loop - P0.25 greater than 0.16 mV, -Pmax greater than 0.22 mV and SP area greater than or equal to 0.03 mV.mV (3 mm2) reflects the initial stage of RAD; 5) changes of normal initial/final vector ratio (-P0,025 greater than or equal to -P0,075 - in normal subjects and P0,075 greater than or equal to P0,025 in patients with RAD) indicate the advanced stage of RAD.

Adolescent↗
PubMed1984

[Method for the automated mapping of 35 ECG leads].

The method of recording the ECGs, inputting them into a computer and automatic analysis of 35 ECG leads is described. The proposed method largely diminishes the time expenditure and difficulties in obtaining and analysing 35 ECG lead mapping grams, as the computer makes all measurements and calculations and produces a final document.

Analog-Digital Conversion↗
PubMed1984

[Spatial parameters of the automatically reproduced QRS loop of the VCG in healthy subjects].

The findings of the VCG automatic construction in 55 healthy subjects with different axial and positional variants of ECG were analyzed . The applied method of the automatic corrected VCG construction has shown that QRS loop morphology coincides with the classical forms of VCG described before in healthy persons. The data of the automatic calculations of spatial characteristics demonstrated the orientation stability according to the angle--azimuth, max QRSxyz , S/2 QRSxyz and the integral vector-- AQRSxyz , i. e. independence of the azimuth value on the ECG axial and positional variants. The positional and rotational shifts regularly change the azimuth value in the spatial orientation of the initial (0.01"--0.02') and end (0.06") moment vector of depolarization, and the value of the angles of spatial vector elevation max QRSxyz , S/2 QRSxyz , AQRSxyz . In the normal intraventricular conduction, the orientations of max QRSxy , yz , xz are sufficiently informative in order to reveal the integral vector directions. The coincidence of S/2 QRSxy , yz , xz direction with that of AQRSxy , yz , xz in the two-polar loops indicates that S/2 QRSxy , yz , xz should be calculated to determine AQRSxy , yz , xz orientation. Indeed, in case of intraventricular conduction disorders, the AQRSxy , yz , xz calculation alone gives an idea of a resultant vector projection.

Adolescent↗
PubMed1983

[Indices of left ventricular hypertrophy based on data from the automatic mapping of 35 ECG leads].

The potential of the method of 35 ECG leads' automatic mapping in the diagnosis of left ventricular hypertrophy was assessed for the first time. A number of mapping indices closely correlating with the myocardial mass and the thickness of the left ventricular wall were found while studying 35 ECG leads' maps followed by computer processing, in 28 hypertensive patients and 6 normal subjects the hypertrophy degree of the left ventricle being determined by echocardiography and X-rays. The index of the total maximum of the R-waves among 7 vertical columns (7.3 +/- 2.0 cm) proved to be simultaneously highly specific (88.9%), sensitive (84%) and accurate (85.3%) to diagnose even a moderate degree of left ventricular hypertrophy (with the left ventricular mass of 150-200 g as evaluated by echocardiography).

Adolescent↗
PubMedDate not supplied

[Inhibition of noradrenaline and choline active capture by rat brain synaptosomes in the presence of terephthalic acid and its dimethyl ester].

The system of [14C] noradrenaline and [3H] choline trapping by rat brain cortex synaptosomes was studied under the effect of terephthalic acid and its dimethyl ester. Active transport of the labeled substances by synaptosome is established to be considerably inhibited under conditions of the inhalation action of terephthalic acid and its dimethyl ester on rats. A possible influence of the mentioned chemical compounds on the mechanism of the reverse trapping of the mediators is under discussion.

Animals↗