Extrasystole Atrioventricular

Atrioventricular extrasystole (EAV) is a pathological syndrome based on the appearance of additional contractions of the ventricular myocardium arising from different parts of the conduction system of the heart, manifested by disturbances in cardiac rhythm and conduction.

The pathogenesis of EAV has not been sufficiently studied, and among researchers in this field there are different points of view about the mechanism of development of this syndrome. It occurs due to an increase in the rate of metabolic processes in the heart, activation of adrenergic and cholinergic receptors of the sinus node. EAV often develops against the background of organic changes in the myocardium, such as arterial hypertension, post-infarction cardiosclerosis, myocardial dystrophies of various origins, cardiomyopathies, electrolyte imbalances, etc. Based on the frequency of occurrence of extrasystoles, two groups can be distinguished: paroxysmal and long-term single (background). They often occur in the morning, often combined into attacks

Extrasystole is a type of heart rhythm disorder, which is characterized by contractions of the heart that bypass its normal rhythm. Extrasysystats are not pathognomonic for any cardiac pathology; they are usually caused by one or another disease of the myocardium itself or a functional disorder of the nervous system responsible for the function

Extrasystole of the atrioventricular connection

** Atrioventricular extrasystoles ** - pathological contractions of the atrioventricular junction and heart rhythm disturbances for more than 60 seconds without known arrhythmogenic causes. In children, adolescents and adults with additional episodes of palpitations, it is preferable to distinguish from the group of ventricular tachycardias with impaired repolarization and hyperdynamics. An acute attack is manifested by a feeling of heartbeat, rhythm intermittency, short-term freezing, signs of arrhythmia on the ECG in the form of polytopic and monotopic extrasy

The ectopic impulse arises in the initial parts of the ventricular tract and spreads retrogradely to the entire ventricular myocardium. This rapid activation of muscle fibers forms pathological atrial ventricular complex activity. Due to the “avoidance” of myocardial ischemia, false extraordinary contractions of the heart muscle occur—extrasystoles.

The pathogenesis of extrasystoles is associated with metabolic and structural disorders of myocardial metabolism during the process of cardiac remodeling in HF, CHF and hypertension. Proximal metapolymeric interstitial-epithelial complexes of the endesmal tissues of the ventricles are a key link in the development of the pathological contractile phenotype of the myocardium - paradoxical arrhythmogenic dystrophy. Metabolic and hemodynamic changes in the myocardial region affect the membrane contours of the basal cells and lead to their electrochemical activation when an ectopic impulse occurs. The formation of a focus of arrhythmic activity begins retrograde due to the initiation of ectopic impulses from synchronously depolarized neighboring myocardium. An episode of randomization of impulses between ventricular fibers creates conditions for excitation of earlier depolarization of the ectopic focus by a refractory interval of repolarization of the adjacent subepicardial myocardium. Its intramural epicardial segment can continue to excite the adjacent section of the myocardium in various parts of the intraventricular Adonia system under the influence of focal depolarization, forming specific segmental myocardial “defects” of segmental resistance. The phenomenon of conductive tachycardia occurs under the action of impulses from the emerging focus of interference with the vegetative and electrical syndrome of hypersynchronization of myocardial tissue fibers, as well as with the development of superficial heterotopic activity of the idioventricular type for cardiac innervation by interventricular fibers of the conduction pathways.

Disturbances in the intramyocardial kinetics of dynamic function and frequency of internal contractions in the myocardium are caused by reciprocal