Time and Frequency Analysis of Heart Rate Variability at Different Sleep Stages of Primary Insomnia

Insomnia is the inability to sleep that causes interruption in sleep. ECG signals which measured during sleep carry valuable information about heart activity. In the current study, ECG signals of 10 primary insomnia patients and 10 healthy controls during four sleep stages namely, N1, N2, N3 and REM were analyzed. Time and frequency domain of Heart Rate Variability (HRV) were computed and statistically analyzed to evaluate existence of statistical significant differences between the two groups at different sleep stages. A high value of LF index was observed during N3 sleep stage in the primary insomnia patient can be regarded as predominant of sympathetic nervous system.