The Impact of Respiratory Events on the Autonomic Nervous System during Sleep

Abstract

Sleep apnea hypopnea syndrome (SAHS) is an independent risk factor for cardiovascular diseases. However, the pathophysiology between them is not yet clear. This paper seeks to understand how respiratory events impact the cardiovascular system by heart rate variability. We compared the differences between successional pathological respiratory events (PR) and pure normal respiration (NR) during sleep. The transitions between normal and pathological respiration (TR) were also analyzed. Thirteen patients who suffered moderate or severe SAHS were enrolled in this study. The results demonstrate that the beat-to-beat interval (RR interval) mean value and sample entropy are significantly lower during PR than during NR. RR interval standard deviation, the power of very low frequency (VLF) and low frequency (LF), total power, and the low frequency/high frequency (LF/HF) ratio were significantly larger during PR than during NR. However, the high frequency (HF) power was not significantly different between normal and pathological respiration. Additionally, the trends during TR also supported these significant differences. The results indicate that during pathological respiration, as the heart rate and its volatility increase, the complexity of its rhythm decreases. We conclude that the energy of the autonomic nervous system rapidly increases during pathological respiration, especially at the beginning. The HF power does not significantly change to modulate the heart rhythm, but the activity of the sympathetic nervous system will significantly increase, resulting in the imbalance of the LF/HF ratio. In addition to these findings, this paper discusses the influence of arousal on these indices during TR.

Global and Transient Effects of Intermittent Hypoxia on Heart Rate Variability Markers: Evaluation Using an Obstructive Sleep Apnea Model

“…This finding was in line with the results reported in Shiomi et al [35], performed with patients suffering from OSA, where increase in VLF power and the presence of a shaped VLF peak, were synchronized with episodes of respiratory arrest or hypoxemia (decreased SaO 2 ) that occurred at cycle lengths of 25-120 seconds. Lianj et al [36] also studied the impact of mixed pathological respiratory events including hypopneas, obstructive and central sleep apneas, reporting increased VLF and LF power compared to normal respiration segments. The influence of sleep stages has also been evaluated independently for pathological respiration and in combination with cortical arousals, with the latter having the greatest impact on LF power [37].…”

Repercussion of medium and long treatment period with continuous positive airways pressure therapy in heart rate variability of obstructive sleep apnea

“…Considering that apnea episodes happen at nighttime, during sleep, the autonomic alterations can also be more significant during this period. As observed, abnormal breathing culminates in sympathetic activity peaks higher than the vagal ones 20 .…”

Diagnosis of Heart Failure Complicated with Sleep Apnea Syndrome by Thoracic Computerized Tomography under Artificial Intelligence Algorithm

“…SNA would get a further development by reducing the stroke volume, inhibiting the sympathetic inhibitory effect of lung extension receptors through apnea, or both. When the SNA is strengthened, the increased left ventricular afterload together with increased heart rate will lead to a mismatch between myocardial oxygen supply and demand, which makes patients acutely susceptible to myocardial ischemia and arrhythmia and chronically susceptible to left ventricular hypertrophy, left ventricular enlargement, and HF [ 18 , 19 ].…”