Auditory-evoked awakening in 3-month-old infants caused an immediate 13% decrease in pulse transit time (approximately 20 msec) that inversely mimicked blood pressure trends.
Observational (n=20)
No
Does auditory-evoked arousal and waking alter pulse transit time and blood pressure in healthy 3-month-old infants?
In healthy 3-month-old infants, pulse transit time decreases significantly upon awakening, inversely mirroring blood pressure increases, suggesting its utility as a non-invasive marker of autonomic arousal during sleep.
STUDY OBJECTIVES: To establish a normal range of data in 3-month-old infants in relation to changes in cardiovascular measurements, with particular reference to pulse transit time (PTT), following subcortical arousals and awakenings from sleep. DESIGN: Prospective study. SETTING: Sleep laboratory, Dunedin Hospital PARTICIPANTS: Twenty healthy infants aged 9-12 weeks. METHODS: Nap studies were performed using a standard polysomnographic setup with the addition of a Portapres blood pressure (BP) cuff (wrist application) and a piezoelectric sensor on the foot. PTT was measured from the ECG-R waveform to the arrival of the pulse peripherally. Infants were exposed to white noise from 50 to 100 dB at 10 dB intervals within REM and NREM sleep. RESULTS: Awakening thresholds were higher (P = 0.01) in NREM (>90 dB) than REM sleep (mean +/- SD; 74.3 +/- 9.4dB). Subcortical thresholds were always 10 dB below waking thresholds. Following awakening, there was an immediate increase in HR, SBP, and DBP of 21%, 14%, and 17%, respectively, and a 13% decrease in PTT returning to baseline within 25-30 seconds. PTT at baseline measured 140 +/- 11 and 139 +/- 9 msec in NREM and REM sleep, respectively, and decreased approximately 20 msec with waking. PTT changes were negatively correlated with heart rate (HR) but not BP, although a trend was evident. CONCLUSIONS: At 3 months of age, infants provoked to arouse from sleep showed PTT changes that inversely mimicked BP trends, suggesting that PTT could be useful in infant studies as a marker for autonomic perturbations that occur during sleep in both clinical and research settings.
Galland et al. (Sun,) conducted a observational in Healthy infants (n=20). Auditory-evoked arousal and waking (white noise) vs. Baseline sleep was evaluated on Changes in cardiovascular measurements, particularly pulse transit time (PTT). Auditory-evoked awakening in 3-month-old infants caused an immediate 13% decrease in pulse transit time (approximately 20 msec) that inversely mimicked blood pressure trends.