Microprocessor based waveform analysis of the fetal electrocardiogram during labor

Publisher Website
Google Scholar
Abstract
An increase in T wave amplitude of the fetal ECG (FECG) has experimentally been correlated to elevated catecholamine levels and myocardial glycogenolysis. The FECG changes have also been described during human delivery. The present aim was to investigate whether these ECG changes could be reproduced in an easily handled real time microprocessor system, and to correlate them to biochemical and clinical data. During 40 deliveries the FECG signal was transferred to a microcomputer system for real time averaging of the FECG. There was a high capacity of the system to reproduce the ST waveform changes though the averaging procedure reduced the QRS magnitude by 10%. With a normal umbilical artery pH (.gtoreq. 7.25) the highest T/QRS ratios recorded during each delivery was 0.26 .+-. 0.19 (mean .+-. S.D.). With lowered pH (< 7.25) the T/QRS increased to 0.33 .+-. 0.10 (P < 0.02). A similar difference between the two groups was seen when the T/QRS ratios from the last hour before birth were compared; 0.13 .+-. 0.08 and 0.18 .+-. 0.05, respectively (P < 0.01). Changes in the ST waveform with T/QRS .gtoreq. 0.30, ST segment alterations, or negative T waves appeared during 40% of the deliveries, however, 30% were short standing changes (< 30 min). Intermediate CTG changes during at least 30 min occurred in 41% and the pattern was classified as abnormal in 18%. Using the scalp electrode as signal source, the ECG analysis could add further information to the routine CTG recording on the fetal condition during delivery.

This publication has 19 references indexed in Scilit: