Fyfe Karinna L, Yiallourou Stephanie R, Wong Flora Y, Odoi Alexsandria, Walker Adrian M, Horne Rosemary S C
The Ritchie Centre, Hudson Institute of Medical Research and Monash University, Melbourne, Australia.
Department of Paediatrics, Monash University, Melbourne, Australia.
Sleep. 2015 Oct 1;38(10):1635-44. doi: 10.5665/sleep.5064.
Preterm birth delays maturation of autonomic cardiovascular control, reflected in reduced heart rate variability (HRV) in preterm compared to term infants at term-equivalent age. It has been suggested that immature cardiovascular control contributes to the increased risk for the sudden infant death syndrome (SIDS) in preterm infants. However, the effects of prone sleeping, the major SIDS risk factor, and of gestational age (GA) at birth on HRV have not been assessed in preterm infants beyond term-equivalent age.
Very preterm (n = 21; mean GA 29.4 ± 0.3 weeks), preterm (n = 14; mean GA 33.5 ± 0.3 weeks), and term (n = 17; mean GA 40.1 ± 0.3 weeks) infants were recruited and underwent daytime polysomnography at 2-4 weeks, 2-3 months, and 5-6 months post-term corrected age (CA). Infants slept both supine and prone. HRV was assessed in the low frequency (LF) and high frequency (HF) ranges.
There was no effect of prone sleeping on HRV parameters in either preterm group. In term infants LF/HF was significantly elevated in the prone position in AS at 2-4 weeks (P < 0.05). HF HRV was significantly reduced (P < 0.05) and LF/HF increased (P < 0.05) in very preterm compared to both preterm and term infants at 2-3 months CA.
Prone sleeping did not significantly impact on heart rate variability (HRV) in preterm infants. However, reduced maturation of high frequency HRV in very preterm infants resulted in significantly altered sympathovagal balance at 2-3 months corrected age, the age of peak sudden infant death syndrome (SIDS) risk. This may contribute to the increased risk of SIDS in infants born at earlier gestational age.
早产会延迟自主心血管控制的成熟，这表现为与足月同龄婴儿相比，早产儿心率变异性（HRV）降低。有人提出，不成熟的心血管控制会导致早产儿患婴儿猝死综合征（SIDS）的风险增加。然而，对于超过足月同龄的早产儿，尚未评估俯卧睡眠（主要的SIDS风险因素）以及出生时的胎龄（GA）对HRV的影响。
招募了极早产儿（n = 21；平均GA 29.4 ± 0.3周）、早产儿（n = 14；平均GA 33.5 ± 0.3周）和足月儿（n = 17；平均GA 40.1 ± 0.3周），并在矫正年龄（CA）的2 - 4周、2 - 3个月和5 - 6个月时进行白天多导睡眠图检查。婴儿分别仰卧和俯卧睡眠。在低频（LF）和高频（HF）范围内评估HRV。
俯卧睡眠对两组早产儿的HRV参数均无影响。在2 - 4周时，足月婴儿在活跃睡眠（AS）中俯卧位时LF/HF显著升高（P < 0.05）。与早产儿和足月儿相比，极早产儿在矫正年龄2 - 3个月时HF HRV显著降低（P < 0.05），LF/HF升高（P < 0.05）。
俯卧睡眠对早产儿的心率变异性（HRV）没有显著影响。然而，极早产儿高频HRV成熟度降低导致在矫正年龄2 - 3个月时交感迷走神经平衡显著改变，这是婴儿猝死综合征（SIDS）风险最高的年龄。这可能导致孕周较小的婴儿患SIDS的风险增加。
