Myocardial biomechanics, intracardiac hemodynamics and endothelial function in patients before and after various types of pacemakers implantation

This review presents 31 sources from 1995 to 2019. Atrioventricular blockades (AVB) 2-3 degrees occupy a special place among the causes of death from cardiovascular disease. The above AVB lead to a significant slowing of the heart rate and predispose to the development and progression of heart failure (HF) and the occurrence of acute hypoxia of the brain and attacks Morgagni-Adams-Stokes. The main method of treatment of hemodynamically significant AB-conduction disorders is electrocardiostimulation (ES), which is the basic method of treatment. A single chamber pacemaker is the most often implanted with using isolated ventricular stimulation in clinical practice in the Russian Federation. Implantation of a dual chamber pacemaker is less frequent. This type of stimulation allows to maintain atrioventricular synchronization constantly. Stimulation of the apex of the right ventricle leads to a decrease in left ventricle (LV) function and structural changes that are a consequence of the occurrence of electric and mechanical dyssynchrony of the myocardium. There is a large number of works devoted to the comparison of different methods of ES leading to the conclusion that a powerful alternative to the stimulation of the apex of the right ventricle can be a dual ventricular stimulation. It is noted that implantation of single-and dual-chamber pacemaker with fixation of the electrode in the region of the right ventricle apex leads to the fact that both modes of stimulation can not cancel the electrical and anatomical remodeling of the myocardium of left atrium and LV. It may be necessary to use a more physiological site of stimulation with using optimal AB-delay to minimize the frequency of ventricular stimulation. Endothelium plays an important and independent role in the development of cardiovascular diseases. The effect of AB conduction impairment on endothelial function (EF) has not been described to date. There were few studies which are discussed the influence of constant pacemaker on endothelial function in patients with AVB 2-3 degrees in recent years. It should be noted that the studies were conducted on a small sample of patients and had a different design.