Investigating the dynamics of atrioventricular delay

We focus on certain types of cardiac arrhythmias that are caused by atrioventricular block (AV block). We investigate how the dynamics of such arrhythmias are altered by the influence of the feedback introduced by the baroreceptor-cardiac reflex. The baroreceptor-cardiac reflex (baroreflex) is the predominant mechanism for the short-term control of blood pressure. Baroreceptors are sensitive to blood pressure and to changes of blood pressure. They convert these variables into neural signals that are sent to the brain. Other time-varying neural activities such as respiratory neurons, affect the cerebral information processing of baroreceptor signals. Autonomic nerves convey the neural impulses to effector organs such as the heart and peripheral resistance vessels, which in turn affect blood pressure to counteract the changes detected by the baroreceptors. This closed-loop control system contains several nonlinearities and time delays that can induce complicated rhythms. In this article we present two different mathematical descriptions of the atrioventricular conduction delay, one with and one without the baroreflex feedback, and compare the dynamics of atrioventricular conduction generated by these models.