Autonomic cardiovascular control is altered by intermittent hypoxia in preterm infants

• Published in: Acta Paediatrica Vol. 112; no. 11; pp. 2359 - 2367
• Main Authors: Yee, Alicia K., Shetty, Marisha, Siriwardhana, Leon S., Wong, Flora Y., Walter, Lisa M., Horne, Rosemary S. C.
• Format: Journal Article
• Language: English
• Published: Stockholm Wiley Subscription Services, Inc 01.11.2023
• Subjects: Apnea; Autonomic nervous system; Cardiovascular system; central apnoea; Heart rate; Hypoxia; Infants; Menstruation; neonatal hypoxia; Neonates; Newborn babies; Parasympathetic nervous system; Premature babies; preterm infant; Respiration; Sleep disorders
• ISSN: 0803-5253; 1651-2227
• DOI: 10.1111/apa.16955

Aim Preterm infants frequently experience short apnoeas and periodic breathing. Animal studies have shown that repetitive hypoxia associated with periodic breathing can alter autonomic control. We aimed to elucidate if apnoea and periodic breathing were associated with changes in autonomic control assessed using heart rate variability, thus exacerbating the consequences of respiratory disturbance. Methods Forty very preterm infants (15 M/25 F) were studied at 34.3 weeks post‐menstrual age with daytime polysomnography. Total power, low frequency (LF, sympathetic+parasympathetic activity) high frequency (HF, parasympathetic activity) and LF/HF (sympathovagal balance) were calculated. Results Infants were divided into those with above and below the median total sleep time spent with respiratory events: Active sleep (AS) 13%, Quiet sleep (QS) 10%. In AS, including respiratory events, Total power (p < 0.05) and HF power (p < 0.05) were higher in the above median group. During AS excluding respiratory events, Total power (p < 0.05) and HF power (p = 0.061) were higher and LF power (p < 0.01) and LF/HF (p < 0.05) were lower in the above median group. There were no differences in HRV parameters in QS. Conclusion This study provides new evidence that short apnoeas, particularly periodic breathing, which is currently not detected or treated in the neonatal unit can affect autonomic cardiovascular control.