Troeger Carolyn, Schaub Andreas F, Bernasconi Paolo, Hösli Irene, Holzgreve Wolfgang
Department of Obstetrics and Gynaecology, University of Basel, Basel, Switzerland.
Fetal Diagn Ther. 2003 Jul-Aug;18(4):284-8. doi: 10.1159/000070811.
Fetal heart rate (FHR) variability is an important indicator of fetal well-being. In fetal tachyarrhythmias, however, visual analysis of FHR variability is limited. We therefore applied power spectral analysis of FHR to evaluate the fetal state.
Fetal R-R intervals were detected by means of an external ECG in 3 fetuses with supraventricular extrasystoles after cardiac malformations had been excluded by fetal echocardiography. Using an autoregressive model, power spectral densities were calculated from 20 consecutive 256-beat segments for the following frequency bands: <0.03 Hz (very low frequency), 0.03-0.069 Hz (low frequency; LF), 0.07-0.129 Hz (mid-frequency) and 0.13-1.0 Hz (high frequency; HF).
The FHR variability in fetal supraventricular extrasystoles mainly resulted from the HF component (63.91 +/- 6.97%). The sympatho-vagal balance (LF/HF) was decreased in the tracings with extrasystoles (0.13).
The analysis of FHR variability in fetal supraventricular extrasystoles revealed an imbalance between sympathetic and parasympathetic regulation.
胎儿心率（FHR）变异性是胎儿健康的重要指标。然而，在胎儿心律失常中，对FHR变异性的视觉分析是有限的。因此，我们应用FHR的功率谱分析来评估胎儿状态。
通过外部心电图检测3例胎儿的R-R间期，这些胎儿在经胎儿超声心动图排除心脏畸形后出现室上性期前收缩。使用自回归模型，从20个连续的256次心跳节段计算以下频段的功率谱密度：<0.03Hz（极低频）、0.03 - 0.069Hz（低频；LF）、0.07 - 0.129Hz（中频）和0.13 - 1.0Hz（高频；HF）。
胎儿室上性期前收缩时的FHR变异性主要由高频成分引起（63.91±6.97%）。伴有期前收缩的记录中交感 - 迷走神经平衡（LF/HF）降低（0.13）。
对胎儿室上性期前收缩时FHR变异性的分析揭示了交感神经和副交感神经调节之间的失衡。
