Features of a probabilistic model of intracardiac electrical activity during atrial fibrillation

Abstract

Electrophysiological models of the heart, developed and studied to date, show the presence of many discrete events in time, leading to the propagation of electrical activity signals and allowing synchronizing (normally) the work of all parts of the heart. When considering models of heart rhythm management, at least two main levels can be distinguished: intra- and extracardiac. Each of these levels can also be divided into several sublevels. Intracardiac effects that regulate heart rate include the myogenic, intercellular, intracardiac nervous system and the effects of intracardiac humoral factors (produced in the heart itself). Extracardiac effects include neuroreflex and general humoral regulation of cardiac activity. Probabilistic models of the processes of cardiac activity are mainly used to describe heart rate variability at an extracardiac level. At the same time, probabilistic models were practically not used for the processes underlying the automatism of the heart at the intracardiac level. A probabilistic model of heart rate dynamics is proposed based on the concept of heart contraction because of the influence of many hierarchical random events. The results of the probabilistic modeling presented in the work are in good agreement with the well-known bioelectric models that describe the dynamics of intracardiac activity and make it possible to use a sequence of RR durations (for example, a rhythmogram and a pulsogram) to detect various latent cardiac abnormalities, in particular, atrial fibrillation.