Heart rate variability in childhood obstructive sleep apnea

Abstract

The identification of patients with obstructive sleep apnea (OSA) is important because of morbidities associated with OSA. A previous adult study demonstrated the use of heart rate variability (HRV) as a tool to identify patients with moderate to severe OSA. Either a reduction in time parameters or an increase in LF/HF ratio was seen at overnight or 24-hr studies suggestive of increased sympathetic modulation. To study the feasibility of daytime HRV as a screening tool, a short-term recording of HRV is studied. Since it was shown in adult study that increased normalized LF, decreased normalized HF and increased LF/HF ratio could be detectable during supine rest at daytime awake period, the authors hypothesize that the differences are also detectable in children. Children who underwent sleep polysomnography for suspected OSA were recruited. Subjects were classified OSA if apnea-hypopnea index (AHI) > 1.5/hr and non-OSA if AHI ≤ 1.5/hr. Continuous 1-hr electrocardiographic monitoring was recorded in awake children during the day. Parameters from time domain and frequency domain were analyzed. Seventy-four male and 17 female snoring subjects were included in this study. Fifty-one (56%) and 40 (44%) of them were classified as "non-OSA" and "OSA," respectively. pNN50, a parameter for parasympathetic modulation, was significantly reduced in the OSA group when compared with the non-OSA group. Using multiple regression, all time domain variables were shown to be decreased in OSA group. Our results suggest that 1-hr study of HRV may be a feasible tool in identifying children with OSA.

Screening obstructive sleep apnea–hypopnea syndrome from snorers in children by heart rate variability analysis

“…This observation was consistent with some studies (Gula et al 2003;Park et al 2008;Kesek et al 2009;Ng et al 2010;Song et al 2012). For the study of HRV during daytime, Kwok et al (2011) did a study which found that PNN50 dropped significantly in the day in OSAS compared with non-OSAS snorers, prompting daytime parasympathetic activity in OSAS children significantly decreased. In our study, RMSSD d , PNN50 d , LF d , and HF d have the tendency of decreasing, whereas LF/HF d has the tendency of increasing, but not significantly, indicating that children with OS-AHS did not differ from non-OSAHS in HRV during daytime and the reason may be that there was large proportion of mild cases of OSAHS in this study.…”

Short-Term Heart Rate Variability in a Population-Based Sample of 10-Year-Old Children

“…These discrepancies may be attributable to prior studies' small sample sizes (e.g., N = 12; 36), posture (e.g., seated vs. supine) [5], time of recording (e.g., upon awakening from sleep) [18], presentation of data reduction techniques (e.g., HRV values presented through graphs only) [8], inconsistencies in units (e.g., beats/min 2 , Hz) [7], and failure to adhere to the Task Force [39] recommendations for spectral analyses [7,8]. Notedly, previously reported values fell within the 5th and 95th percentile values observed in the present population-based sample.…”

“…Existing referent values are based on studies with methodological limitations including use of small samples (e.g., 10), combining broad age ranges [18], use of convenience "healthy controls" [5,35] or clinical samples [3], varying duration of ECG recording (e.g., 2 min to 24 h), inaccurate frequency bandwidths for spectral analysis parameters [7,10,26], and reporting HRV values using inconsistent units (e.g., beats/min 2 , log transformed, absolute, normalized). Further, important developmental factors are often not considered.…”

“…Further, important developmental factors are often not considered. Limited findings suggest younger age [19,37], pubertal status [5], greater physical activity [5,26], and consolidated sleep [18,19] are associated with a predominance of parasympathetic activity and reduced sympathetic modulation; yet, these have not been considered when deriving normative values. Collectively, these limitations hinder and bias interpretation and their practical applicability among clinicians.…”

Pulse rate variability compared with heart rate variability in children with and without sleep disordered breathing

“…These studies have showed that increased heart rate [4], elevated sympathetic activity [5] and higher LF to HF ratio (LF/HF) [6] are apparent during sleep disordered breathing.…”