Information-Theoretic Analysis of Cardiorespiratory Interactions during Apneic Events in Sleep

Abstract

In this work, measures of information dynamics are used to describe the dynamics of heart rate and cardiorespiratory interaction associated to sleep breathing disorders. In a large group of patients reporting repeated episodes of hypopneas, apneas (central, obstructive, mixed) and respiratory effort related arousals (RERA), we computed information storage of heart period variability and information transfer from heart period to airflow amplitude before, during and after each event. We find a general tendency to decrease of the information storage, suggesting higher complexity of the cardiac dynamics. The information transfer decreased during apneic events, and increased during milder disorders hypopneas and RERA. These findings reflect the impact of different sleep breathing disorders on respiratory sinus arrhythmia, and may have physiological and clinical relevance.