The regularity of changes in the electrical resistance of the myocardium as an indirect confirmation of the phenomenon of alternate contraction of cardiomyocyte clusters

Despite modern knowledge about the physiology of the heart, the processes of regulation of the contractile function of the myocardium in conditions of rest, physical activity and stress remain completely unexplored. The complex effect of the sympathetic and parasympathetic nervous system on the myocardium, the connection of various numerous intra- and extracardial regulatory mechanisms contributes to the possibility of alternately reducing individual associations of cardiomyocytes, which provides energetically more beneficial heart function. The study of the regulation of cardiac activity may be associated with the use of methods based on the measurement of tissue impedance, which are now widely used in various biomedical research. Objective: to determine fluctuations in the electrical resistance of various zones of the myocardium in a state of functional rest and during stimulation of the parasympathetic and sympathetic parts of the nervous system. Materials and methods. Chinchilla rabbits (n = 24) underwent dissection of the right and left vagus nerves, stellate ganglion. Electrodes were installed subepicardially in the myocardium of the anterior wall of the left ventricle to register the myocardial impedance. The arterial pressure in the carotid artery was measured invasively throughout the experiment. The increased load on the myocardium was created by irritation of the right stellate ganglion with current pulses of 3-7 mV, 2 ms; of the right vagus nerve - 1.5-5 mV, 2 ms. Results. A statistically significant difference was revealed between three myocardial clusters with resistance fluctuations of high amplitude (8.0-11.0), medium (3.0-8.0) and low (less than 3.0), (p function show_eabstract() { $('#eabstract1').hide(); $('#eabstract2').show(); $('#eabstract_expand').hide(); }