Autonomic Dysfunction Increases Cardiovascular Risk in the Presence of Sleep Apnea

Abstract

The high prevalence of sleep apnea syndrome (SAS) and its direct relationship with an augmented risk of cardiovascular disease (CVD) have raised SAS as a primary public health problem. For this reason, extensive research aiming to understand the interaction between both conditions has been conducted. The advances in non-invasive autonomic nervous system (ANS) monitoring through heart rate variability (HRV) analysis have revealed an increased sympathetic dominance in subjects suffering from SAS when compared with controls. Similarly, HRV analysis of subjects with CVD suggests altered autonomic activity. In this work, we investigated the altered autonomic control in subjects suffering from SAS and CVD simultaneously when compared with SAS patients, as well as the possibility that ANS assessment may be useful for the early stage identification of cardiovascular risk in subjects with SAS. The analysis was performed over 199 subjects from two independent datasets during night-time, and the effects of the physiological response following an apneic episode, sleep stages, and respiration on HRV were taken into account. Results, as measured by HRV, suggest a decreased sympathetic dominance in those subjects suffering from both conditions, as well as in subjects with SAS that will develop CVDs, which was reflected in a significantly reduced sympathovagal balance ( p < 0.05). In this way, ANS monitoring could contribute to improve screening and diagnosis, and eventually aid in the phenotyping of patients, as an altered response might have direct implications on cardiovascular health.

Cardiopulmonary coupling indices to assess weaning readiness from mechanical ventilation

“…Moreover, these differences in the CPC parameters are more evident during sleep than right before the SBT, what could be due to the loop gain. In other words, patients with failed weaning may be experiencing more apnoea events at night, which is directly related to a reduced RSA and higher cardiovascular risk 31 , 56 . In fact, the parasympathetic activity is well known to be predominant during sleep at night and, consequently, it is in this moment when the CPC mechanism is stronger.…”

Effect of Hyperventilation on Periodic Repolarization Dynamics

“…Respiratory dysfunction can influence cardiovascular health, and cardiovascular diseases are often associated with respiratory diseases ( Garcia et al, 2013 ). Breathing disorders and pulmonary diseases are tightly linked to autonomic dysfunction ( van Gestel and Steier, 2010 ; Milagro et al, 2019 ). On the other hand, it has been demonstrated that the maintenance of correct cardiorespiratory coupling exerts beneficial cardiovascular effects in patients with an attenuated RSA ( Ben-Tal et al, 2012 ).…”

Weaning from Mechanical Ventilation: On the Improvement of the Prediction of Patients' Readiness with Cardiopulmonary Coupling Indices

“…Moreover, these differences in the CPC parameters are more evident during sleep than right before the SBT, what could be due to the loop gain. In other words, patients with failed weaning might be experiencing more apnoea events during the night, which is directly related to a reduced RSA and a higher cardiovascular risk 40,67 . In fact, the PNS activity is well known to be predominant during sleep at night.…”