[Cardioelectrical field on the body surface of newborn nestlings of the pied flycatcher (Ficedula hypoleuca) at the period of initial atrial activity].

By electrocardiotopographic method the dynamics of electrical field has been studied on the body surface of newborn nestlings of the pied flycatcher (Ficedula hypoleuca) at the period of atrial depolarization. On the body surface there have been revealed two shifts of zones of positive and negative cardiopotentials of the heart electrical field, which are due to peculiarities of sequence of atrial depolarization, anatomical immaturity of atrial structures. and the oresence of closed foramen ovale.

Depolarization of atrial epicardium near pulmonary veins orifices in hypertensive ISIAH rats.

The formation of early activation regions was demonstrated in the area of the pulmonary vein orifice in hypertensive rats. The appearance of early activation zones on the dorsal side of the left atrium near the pulmonary veins simultaneously with the sinoatrial node in rats with arterial hypertension indicates the possibility of ectopic foci formation in the area of pulmonary vein sleeves.

[Sequence of depolarization of atrial myocardium of the pig (Sus scrofa domesticus)].

By the method of multichannel synchronous cardioelectropotography, sequence of depolarization of intramural atrial layers was studied in representatives of ungulate animals--pigs. In the pig atrial myocardium there is revealed a complex picture of spreading of activation fronts, connected with non-uniform anatomical structure and subendocardial (intramural) disposition of area of initial activation. The general character of sequence of depolarization of the pig atrial myocardium is comparable with carnivores (dog) and even-toed (sheep) animals.

[Cardioelectric field on the atrial surface in pigs].

The form and distribution of extracellular cardioelectric potentials and the sequence of the excitation wave propagation on epicardium of the pig atria were studied by the method of multichannel synchronous cardioelectrotopography. The studies have shown that in pig the excitation wave breaks on epicardium of the right atrium at the base of the upper vena cava. Negative initial atrial complexes are registered in this area. Two fronts of excitation wave spread from the zone of initial epicardial activation: one--to upper segments of dorsal and ventral sides of the right atrium, the second--to inter-atrial septum. The excitation wave comes to the left atrium with a delay relative to the beginning of depolarization of the right atrium. On account of the successive movement of the front of the excitation wave from pacemaker the two-phase potentials are formed on greater part of the epicardium of the pig atria. The lower part of the auricle of the left atrium is depolarized in atrial epicardium in the last turn. The sequence of excitation wave propagation in atrial epicardium close to ravenous (dog) and ungulate (sheep) animals and man is typical for the pig, but herewith the differences in time of covering the atria with excitation do exist.

Effect of torso shape and heart location in the chest on formation of cardiac electric potentials on body surface in dogs.

Experimental and theoretical methods were employed to study the effects of torso shape and heart orientation in the thoracic cavity on peculiarities of the formation cardiac electric field on the body surface in dogs. It was found that heart orientation to a greater extent than torso shape affected projections of cardiac electric potentials from the epicardium onto the body surface.

[Current understanding of the pathogenesis of infectious diseases]. / Sovremennye predstableniia o patogeneze infektsionnykh zabolevanii.

New experimental data in such research fields as molecular biology, biochemistry, genomics and others as well as the changes occurring in the medical-and-epidemiological situation in respect to a number of infectious diseases dictate the necessity to systemize and to revise the appropriate knowledge for the purpose of ensuring a more profound understanding of the processes providing a foundation for the relations within the system of "host--parasite". The article deals with modern aspects of investigating the pathogenesis of infectious diseases, i.e. issues of the genetic and of structural-and-functional organization as well as of regulation of the pathogenetic potential of microorganisms; and mechanism of antimicrobial protection of microorganisms including from the standpoint of evolutionary biology.

Time correlation between initial activation of ventricular myocardium and cardiac electric potentials on body surface in dogs.

Parameters of cardioelectric field on body surface and propagation of excitation in ventricular myocardium during initial activation were studied using multichannel synchronous electrocardiotopography. It was shown that inversion of areas of negative and positive potentials of cardioelectric field on body surface at the moment of excitation propagation to the epicardium reflected changes in the main direction of excitation wavefront in ventricles.

[Reflection of distribution of the epicardial ventricular potential on the dog body surface during electrical stimulation of the myocardium]. / Otobrazhenie na poverkhnosti tulovishcha sobaki raspredeleniia potentsiala na épikarde zheludochkov pri élektricheskoi stimuliatsii miokarda.

Electrical pacing of the apex, base, and free wall of the heart right and left ventricles, as well as the left ventricle's interventricular septum revealed that localisation of the ectopic focus determined the sequence of ventricular depolarisation, the site formation, and the pathway of displacement of the areas' positive and negative potentials and their extrema on the thoracic surface. Time of the mutual movement (inversion) of positive and negative zones on the body surface was found to depend on the pacing site in the wall of ventricles.

[Effect of hypothermia on sequence of the ventricle epicardium repolarization in rabbits]. / Vliianie gipotermii na posledovatel'nost' repoliarizatsii épikarda zheludochkov krolika.

In anaesthetised rabbits at normal body temperature, the earliest ventricles' epicardial recovery occurs at the heart apex and adjacent left ventricle's surface whereas the latest one occurs at the epicardium of the right ventricle's base. A decrease in the mediastinum temperature to 32 degrees C reversed the recovery sequence. Following the cooling of the heart, the longest prolongation of the activation-recovery interval occurred at the heart apex area and the lowest one--at the right ventricle base.

[Time correlation of the cardiac electric field on the body surface and depolarization sequences in the pigeon heart ventricle epicardium]. / Korreliatsiia kardioélektricheskogo polia na poverkhnosti tulovishcha i posledovatel'nosti depoliarizatsii épikarda zheludochkov serdtsa u golubia.

Multifocal depolarisation of the pigeon ventricle's epicardium was revealed. A time inversion correlation was found between cardiac electrical field's positive and negative areas on the body surface and the multifocal depolarisation of the ventricle epicardium, during the period of initial ventricular activity.

[The formation of cardiac-electric-field potentials on the surface of the heart and torso in vertebrate animals]. / Formirovanie potentsialov kardioélektricheskogo polia na poverkhnosti serdtsa i tulovishcha u pozvonochnykh zhivotnykh.

The comparative electrophysiological study of excitation process in heart with different types of organization have laid the foundation for solution of the problems of formation of cardioelectric field. It was shown, that the form of extracellular potentials on the epicardium correlated with different types of ventricle myocardial activation. Animals with the "flash" type of myocardial depolarization in most cases have the negative extracellular potentials in the greater part of the epicardial ventricular surface. Animals with the consecutive type of myocardial activation--the positive and biphase potentials. All myocardial layers (epicardial, intramural and endocardial) are electrophysiologically informative.

[The dynamics of the form of the extracellular potentials and of the process of depolarization wave spreading in the intramural layers of the myocardium in dogs with experimental ischemia]. / Dinamika formy vnekletochnykh potentsialov i protsessa rasprostraneniia volny depoliarizatsii v intramural'nykh sloiakh miokarda sobaki pri éksperimental'noi ishemii.

The reversal of directions and local delays or accelerations of the extracellular potentials evolution occurred at arrival of the depolarization wave after coronary occlusion in dogs. General patterns of directions of the activation spread changed relatively little when compared to normal. Apparently, in spite of the ligation of the left anterior descending coronary artery, ischemia was not achieved. There was some additional blood supply to the ischemic myocardium from deep collateral arterial branches. Therefore, the observed abnormalities of electrical potentials and the reversals of the depolarization wave direction only took place in local small zones of ischemic myocardium.