Cardiac time intervals of normal fetuses using noninvasive fetal electrocardiography
Article first published online: 20 JUL 2005
Copyright © 2005 John Wiley & Sons, Ltd.
Volume 25, Issue 7, pages 546–552, July 2005
How to Cite
Chia, E. L., Ho, T. F., Rauff, M. and Yip, W. C. L. (2005), Cardiac time intervals of normal fetuses using noninvasive fetal electrocardiography. Prenat. Diagn., 25: 546–552. doi: 10.1002/pd.1184
- Issue published online: 20 JUL 2005
- Article first published online: 20 JUL 2005
- Manuscript Accepted: 29 MAR 2005
- Manuscript Revised: 7 MAR 2005
- Manuscript Received: 27 JUL 2004
- National Medical Research Council of Singapore. Grant Number: NMRC/0455/2000
- fetal electrocardiography;
- cardiac time intervals;
- fetal heart
To evaluate the fetal cardiac time intervals from the longitudinal analysis of noninvasive fetal electrocardiography (fECG) in normal pregnancies.
One hundred singleton pregnancies were examined in this longitudinal study. Cardiac time intervals were derived from fetal electrocardiograms obtained noninvasively using three electrodes placed on the maternal abdomen. The variables measured included the durations of the P wave, PR interval, QRS complex, QT interval and T wave.
Success rates for detecting the P, QRS and T waves were 74.6, 91.0 and 79.3%, respectively. Cardiac time intervals were significantly influenced by fetal age. The mean P-wave duration increased from 43.9 (18–22 weeks) to 52.9 ms (≥37 weeks) (p < 0.001). PR intervals were 102.1 and 110.1 ms, for fetuses at 18 to 22 and ≥37 weeks (p < 0.001), respectively. QRS intervals were 47.2 and 52.6 ms (p < 0.001), while QT intervals were 224.0 and 242.7 ms (p < 0.001), at 18 to 22 and ≥37 weeks respectively. From 18 to 22 weeks to ≥37 weeks, QTc values increased from 343.8 to 367.7 ms (p < 0.001), while T-wave durations increased from 123.8 to 152.4 ms (p < 0.001).
Serial noninvasive fECG of normal fetuses from 18 to 41 weeks of gestation show good success rates of fECG detection. Cardiac time intervals generally increased with increasing gestational age. Copyright © 2005 John Wiley & Sons, Ltd.