Kariniemi V, Siimes A, Ammälä P
J Perinat Med. 1982;10(2):114-8. doi: 10.1515/jpme.1982.10.2.114.
The success rate of some methodological factors influencing the antepartal analysis of fetal heart rate variability (FHRV) by abdominal electrocardiography (aFECG) were studied in 80 normal and 554 high risk pregnancies. The success rate of FHRV analysis was found to be dependent on the gestational age with virtually 100% success at 22 to 25 weeks and at 40 to 41 weeks of gestation. The lowest rate of success, 50% was found around the 30th week of gestation (Fig. 1). The fifteen-degree lateral tilt and the supine position of the mother were found to be equal respecting the success rate and the test results, while the 90-degree lateral tilt was found to be less favorable for the analysis. FHRV analysis succeeded more often with electrode paste than it did with tap water moistening or with dry electrodes. The rejection limit of maximum interval differences in FHRV analysis was found to be an important factor influencing the test results. The variability indices should be compared only if they have been measured with the same rejection logic. Differential index, of short-term variability, can be measured from short samples of aFECG, having a good correlation between DIs measured using 1-minute, 5-minute and 20-minute samples (Figs. 3, 4). On the other hand, interval index measuring the long-term variability should be measured using longer samples of aFECG.
在80例正常妊娠和554例高危妊娠中，研究了一些影响经腹心电图（aFECG）进行胎儿心率变异性（FHRV）产前分析的方法学因素的成功率。发现FHRV分析的成功率取决于孕周，在妊娠22至25周以及40至41周时成功率几乎为100%。在妊娠第30周左右发现成功率最低，为50%（图1）。发现母亲的15度侧卧位和仰卧位在成功率和测试结果方面相当，而90度侧卧位对分析不太有利。使用电极糊进行FHRV分析比用自来水湿润或使用干电极更常成功。发现FHRV分析中最大间期差异的剔除限度是影响测试结果的一个重要因素。只有在使用相同剔除逻辑进行测量时，才可比较变异性指标。短期变异性的差异指数可从aFECG的短样本中测量，使用1分钟、5分钟和20分钟样本测量的差异指数之间具有良好的相关性（图3、4）。另一方面，测量长期变异性的间期指数应使用更长的aFECG样本进行测量。
