Pulse wave amplitude and heart period variability in children with upper airway obstruction.

OBJECTIVE:The aim of this study was to assess cardiovascular autonomic modulation in children with upper airway obstruction (UAO), to compare this modulation to that of non-snoring children and to investigate the effect of adenotonsillectomy (AT). METHODS:ECG and finger photoplethysmographic signals obtained from overnight polysomnographic (PSG) recordings of 31 children with mild-to-moderate UAO and 34 non-snoring children were analysed. The extent of autonomic modulation was assessed by symbolic analysis of heart period (HP), pulse wave amplitude (PWA), and their joint dynamics during non-rapid eye movement (NREM) sleep and rapid eye movement (REM) sleep. RESULTS:Children with UAO showed more frequent patterns of monotonically increasing and decreasing HP in NREM sleep and monotonically increasing and decreasing joint PWA-HP patterns in REM and NREM sleep at baseline compared to controls, even when considering only periods of sleep free of discrete respiratory events. Following AT, HP, and joint PWA-HP dynamics significantly altered towards levels observed in the control group. CONCLUSIONS:In children with mild-to-moderate UAO, cardiovascular autonomic modulation is more prevalent, even during quiet, event-free sleep. AT appears to reverse this pattern.