[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.