Computer-based analysis of continuous non-invasive blood pressure and heart rate variability-methodology and normal values during wakefulness and sleep.
Polysomnographic recordings were made in 10 healthy male adult subjects (mean age 25.1 +/- 2.8 years). Parameters were obtained from continuous non-invasive measurement of blood pressure and from heart rate spectra analysed both in the waking state and during sleep (stage 4). The total heart rate variability (mean +/- SE) was not significantly diminished (p < 0.2; paired t-test) during stage 4 sleep (6.2 +/- 0.5%) as compared with the waking state (7.1 +/- 0.5%). The relative heart rate variability coefficient within the frequency band HRV-II ((3-9)/min) was, however, significantly higher (p < 0.001) during slow-wave sleep (0.55 +/- 0.04) than during wakefulness (0.34 +/- 0.04). This fact is in accordance with results concerning an estimated value of the baroreflex sensitivity, which was also significantly higher (p < 0.001) during sleep stage 4 (7.0 +/- 0.8 ms/mmHg vs. 10.4 +/- 1.4 mmHg).
AG für Biomedizinische Technik, Karl-Franzens-Universität Graz.
G
G
Litscher
G
G
Schwarz
G
G
Pfurtscheller
D000328:Adult; D015924:Blood Pressure Monitors; D004562:Electrocardiography / Q000295:instrumentation*; D005583:Fourier Analysis; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D017286:Polysomnography / Q000295:instrumentation*; D012016:Reference Values; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D012894:Sleep Stages / Q000502:physiology; D014851:Wakefulness / Q000502:physiology