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 P-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 P-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.

Body Surface Potential Mapping during Ventricular Depolarization in Athletes with Prolonged PQ Interval after Exercise.

Background: Prolongation of the PQ interval, generally associated with an atrioventricular conduction delay, may be related to changes in intraventricular impulse spreading.

Objective: To assess, using body surface potential mapping (BSPM), the process of ventricular depolarization in athletes with prolonged PQ intervals at rest and after exercise.

Methods: The study included 7 cross-country skiers with a PQ interval of more than 200 ms (Prolonged-PQ group) and 7 with a PQ interval of less than 200 ms (Normal-PQ group).

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.

Body Surface Potential Mapping during Ventricular Depolarization in Rats after Acute Exhaustive Exercise.

Background: Exhaustive physical exercise can cause substantial changes in the electrical properties of the myocardium.

Objective: To evaluate, using body surface potential mapping, the electrical activity of the heart in rats during ventricular depolarization after acute exhaustive exercise.

Methods: Twelve-week-old male rats were submitted to acute treadmill exercise at 36 m/min until exhaustion.

Body Surface Potential Mapping During Heart Ventricular Repolarization in Male Swimmers and Untrained Persons Under Hypoxic and Hypercapnic Hypoxia.

Ivonina, Natalya I., Andrey A. Fokin, and Irina M.

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.

[THE HEART ELECTRIC FIELD ON THE THORAX SURFACE OF SPORTSMEN-SWIMMERS DURING VENTRICULAR REPOLARIZATION UNDER ACUTE NORMOBARIC HYPOXIA].

The study of the electrical activity of the sportsmen-swimmers' heart has been carried out during ventricular repolarization under short-term acute moderate normobaric hypoxia. It was revealed that acute hypoxia leads to a significant decrease of the duration of the early ventricular repolarization immediately after hypoxic exposure, of the duration of the late repolarization - at last minutes. The structural change of ventricular repolarization of the heart of the athletes surveyed was shown based on the changes in amplitude-temporal characteristics of the extrema of the heart electric field during the ventricular repolarization of the heart upon acute hypoxic exposure.

[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.

Comparison of propagation of atrial excitation with the cardiopotential distribution on the body surface of hypertensive rats.

Objective: Arterial hypertension is associated with the risk of developing atrial arrhythmia. This research was aimed at studying the sequence of depolarization along the atrial epicardium and formation of the cardioelectric field on the body surface of hypertensive rats.

Methods: The study was carried out on eleven ISIAH rats (with hereditary stress-induced hypertension).

Morphology of moderator bands (septomarginal trabecula) in porcine heart ventricles.

The morphology of moderator bands in both heart ventricular cavities was examined on macro- and microscopic levels in 14 six-month-old Landrace pigs. One transverse moderator band, measuring 2.9 ± 0.

Ventricular repolarization pattern under heart cooling in the rabbit.

Aim: Prolongation of ventricular repolarization is characteristic of myocardial cooling. In the present study, we investigated whether this prolongation is uniform or not throughout ventricular epicardium and how these hypothermia-induced changes express in the body surface potential distribution.

Methods: Epicardial and body surface potential mapping from 64 unipolar leads was carried out in 18 anaesthetized adult rabbits.

Heterogeneity of propagation of excitation in epicardium of pulmonary veins ostia in rabbit during cooling.

Objective: The purpose of this research was to study the propagation of the excitation wave along epicardium in the area of the pulmonary veins ostia in rabbit in normal conditions and while cooling.

Methods: The excitation wave spreading along epicardium in the area of pulmonary veins ostia in the left atrium at 36-37 degrees C and when cooling to 32 degrees C was studied by the method of electrocardiochronotopography in rabbit of Chinchilla species, five months age. The size of the registering surface of the electrode was 1.

Activation and repolarization patterns in the ventricular epicardium under sinus rhythm in frog and rabbit hearts.

Our study compared the contributions of activation sequence and local repolarization durations distribution in the organization of epicardial repolarization in animals with fast (rabbit) and slow (frog) myocardial activation under sinus rhythm. Activation times, repolarization times and activation-recovery intervals (ARI) were obtained from ventricular epicardial unipolar electrograms recorded in 13 Chinchilla rabbits (Oryctolagus cuniculus) and 10 frogs (Rana temporaria). In frogs, depolarization travels from the atrioventricular ring radially.