Body Surface Potential Mapping during Atrial Depolarization in Rats with Post-Infarction Chronic Heart Failure against the Background of Fabomotizole Therapy.

Cardiac remodeling in rats with post-infarction chronic heart failure caused by anterior transmural myocardial infarction leads to an atypical location of areas of positive and negative cardioelectric potentials on the body surface before the onset of the PII-wave on the ECG in the limb leads, which is a sign of increased heterogeneity of atrial depolarization associated with the appearance of additional excitation focus in the left atrium. A course of therapy with fabomotizole leads to a decrease in the heterogeneity of atrial depolarization at the initial stages of the formation of the cardioelectric field of the atria on the body surface before the onset of the PII-wave, thereby producing an antiarrhythmic effect.

Correlation of the Left Ventricular Systolic Dysfunction and Ventricular Depolarization in a Post-Infarction Model of Chronic Heart Failure.

The body surface potential mapping of the heart during the period of ventricular depolarization and the inotropic function of the ventricles were studied in rats under conditions of a translational model of post-infarction chronic heart failure developed by us. We revealed a statistically significant (p<0.001) correlation between the left-ventricular ejection fraction and the values of the maximum positive and negative extrema of the cardioelectric field on the body surface of rats with post-infarction chronic heart failure caused by anterior transmural myocardial infarction. The calculated linear regression equations have high predictive efficiency, which makes it possible to use the amplitude characteristics of the heart cardioelectric field as a marker of the development of chronic heart failure.

Dynamics of the Cardioelectric Field on the Body Surface during Atrial Depolarization in Rats with Experimental Holiday Heart Syndrome.

In model experiments reproducing the holiday heart syndrome in rats, a discrepancy between the depolarization of the right and left atria has been revealed, which manifested by an atypical arrangement of positive and negative cardiopotentials in the cardioelectric field on the body surface during the P wave and the absence of inversion of the areas of cardioelectric potentials before the onset of P waves in lead II ECG from the limbs.

Depolarization of the Atrial Subepicardium in Rats with Experimentally Induced Pulmonary Hypertension.

Using an experimental model of pulmonary hypertension in rats (monocrotaline in a dose of 60 mg/kg), we revealed an additional focus of early excitation in the zone where the pulmonary veins enter the left atrium, in addition to the main focus in the sinoatrial node. Pulmonary hypertension leads to the formation of regions of early activation in the right and left atria and a significant change in the sequence of atrial depolarization. Propagation of independent excitation waves in the right and left atria increases heterogeneity of depolarization and leads to the formation of atrial arrhythmias.

Depolarization of the Rat Atria in Experimental Simulation of the Holiday Heart Syndrome.

In the study of the sequence of depolarization of the atrial subepicardium of rats in the short-term alcohol consumption model (the "Holiday heart" syndrome), the localization of the sources of atrial arrhythmias was determined for the first time. The difference in the excitation of the right and left atria was discovered: the right atrium is activated anterogradely from the sinoatrial node, whereas the left atrium is activated retrogradely from the ectopic focus located in the left auricular appendage.

Specific Features of Depolarization of the Left and Right Atria in Rats with Alcoholic Cardiomyopathy.

Using a translation model of alcoholic cardiomyopathy in rats we showed the presence of an additional abnormal excitation focus in the area of the pulmonary vein lacunae in the left atrium and enhanced heterogeneity of the atrium depolarization pattern. These changes can determine electric instability of the myocardium and induce malignant heart rhythm disturbances including, sudden cardiac death.

Atria Depolarization in Rats with Alcoholic Cardiomyopathy.

Chronotopography of atrial subepicardium depolarization has been studied in a rat model of alcoholic cardiomyopathy. Formation of independent sources of initial atrial activity has been detected in the right and left atria. These sources induced the formation of several depolarization fronts that propagated autonomously, and this can be regarded as the cause of atrial arrhythmia.

Cardiac Body Surface Potentials in Rats with Experimental Pulmonary Hypertension during Ventricular Depolarization.

The spatial and the amplitude-temporal parameters of cardiac body surface potentials were examined in female Wistar rats with experimental pulmonary hypertension during ventricular depolarization. The cardiac body surface potentials have been led from 64 subcutaneous electrodes evenly distributed across the chest surface prior to and 4 weeks after subcutaneous injection of a single dose of monocrotaline (60 mg/kg). Right ventricular hypertrophy and electrophysiological remodeling of the heart developed in rats with experimental pulmonary hypertension in 4 weeks after monocrotaline injection; these changes led to a significant increase in amplitude and temporal characteristics of the cardioelectric field on the body surface in comparison with the initial state.

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.

[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.

[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.