Heart rate variability on sleep onset process and alternation of sleep stages

Examination of heart rate variability (HRV) on sleep onset period and alternation of NREM-REM sleep stages were studied. groups. However, CAP parameters could clearly distinguished insomnia group from control group, indicating the increase in CAP rate (66.8 ± 7.75% vs. 38.0 ± 7.75%), CAP time (171 ± 37.7 min vs. 117 ± 21.0 min), and the numbers of CAP cycles (408 ± 108 vs. 259 ± 67.2), respectively. These results suggest that CAP parameters were more useful indicators to assess sleep disturbance of insomniac patients than conventional PSG parameters.