Stochastic models of the slow/fast type of atrioventricular nodal reentrant tachycardia and tachycardia with conduction aberration

Abstract

Models are proposed to describe the heart's action potential. A system of stochastic differential equations is used to recreate pathological behaviour in the heart such as atrioventricular nodal reentrant tachycardia (AVNRT) and also AVNRT with conduction aberration. Part of the population has abnormal accessory pathways: fast and slow. An additional pathway is not always induced, since the deterministic model is not proper due to a stochasticity in this process. Introduction of a stochastic term allows modelling a pre-excitation perturbation (such as unexpected excitation by premature contractions in atrium (PAC)) which triggers the mechanism of AVNRT. Also, a system of AVNRT with additional conduction aberration, which is a rare type of arrhythmia, is considered. The aim of this work is to propose a mathematical model superior to the deterministic one that recreates this disease better and allows understanding its mechanism and physical dependencies, which may help to propose a new therapy of AVNRT. Results are illustrated with numerical solutions.

Constant Q-transform-based deep learning architecture for detection of obstructive sleep apnea

“…Polysomnography (PSG) is used as a standard method to diagnose sleep apnea. A polysomnography (PSG) signal is made up of 16 different physiological signals that are recorded overnight, such as electroencephalograms (EEG), electrocardiograms (ECG), electrooculograms (EOGs), electromyograms (EMG), oxygen saturation in the blood (SpO2), respiratory effort, airflow signals, and so on (Wang et al, 2019a;Jackowska-Zduniak, 2022). Based on these signals, the AHI (apnea-hypoapnea index) is evaluated by the professionals for clinical diagnosis of OSA, i.e., an AHI < 5 events/hr is normal, an AHI between 5 and 15 events/hr is considered as mild OSA, an AHI between 15 and 30 events/hr is moderate OSA and an AHI greater than 30 events/hr is regarded as severe OSA (Ramar and Guilleminault, 2008).…”