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Published on: June 29, 2013
Investigating myocardial performance in normal and sick fetuses by abdominal Doppler signal derived indices
Ahsan H Khandoker1, Haitham M Al-Angari1, Faezeh Marzbanrad2
1Healthcare Engineering Innovation Center (HEIC), Department of Biomedical Engineering Department, Khalifa University, PO Box 127788, Abu Dhabi, United Arab Emirates.
Insights
The modified Tei Index (KI) shows significant changes with fetal development and abnormalities, unlike the standard Tei Index (TI). KI may help monitor fetal heart function and detect congenital heart diseases.
Area of Science:
- Cardiology
- Fetal Medicine
- Biomedical Engineering
Background:
- Fetal myocardial performance indices assess systolic and diastolic function.
- Normal values for Tei Index (TI) and modified TI (KI) are crucial for evaluating fetal heart health.
- Abnormalities can impact fetal cardiac performance.
Purpose of the Study:
- Determine normal values of TI and KI across gestational ages (early, mid, late).
- Assess TI and KI in normal fetuses and those with various abnormalities (including CHDs).
- Evaluate the utility of TI and KI in monitoring fetal myocardial function.
Main Methods:
- Simultaneous recording of Fetal Electrocardiogram Signals (FES) and Doppler Ultrasound Signal (DUS) from 55 normal and 25 abnormal fetuses.
- Automated estimation of isovolumic contraction time (ICT), isovolumic relaxation time (IRT), ventricular ejection time (VET), and ventricular filling time (VFT) using a hybrid Hidden Markov and Support Vector Machine model.
- Calculation of TI [(ICT + IRT)/VET] and KI [(ICT + IRT)/VFT].
Main Results:
- Tei Index (TI) showed no significant changes with gestational age or between normal and abnormal fetuses.
- Modified TI (KI) significantly declined with advancing gestational age in normal fetuses.
- KI values were significantly lower in abnormal fetuses compared to normal ones, with a significant correlation (r=-0.36, p<0.01) with gestational age.
Conclusions:
- Modified TI (KI) is a sensitive indicator of normal fetal myocardial development.
- KI can help identify fetuses with various congenital heart diseases (CHDs) and non-CHDs.
- KI holds potential as a valuable tool for monitoring fetal cardiac function.
Introduction:
Fetal myocardial performance indices are applied to assess aspects of systolic and diastolic function in developing fetal heart. The aim of this study was to determine normal values of Tei Index (TI) and modified TI (KI) for systolic and diastolic performance in early (<30 weeks), Mid (30-35 weeks) and late (36-41 weeks) relating to both normal fetuses as well as fetuses carrying a variety of fetal abnormalities, which do not call for precise anatomic imaging.
Material And Methods:
Fetal Electrocardiogram Signals (FES) and Doppler Ultrasound Signal (DUS) were simultaneously documented from 55 normal and 25 abnormal fetuses with a variety of abnormalities including Congenital Heart Diseases (CHDs) and a variety of non-CHDs. The isovolumic contraction time (ICT), isovolumic relaxation time (IRT), ventricular ejection time (VET) and ventricular filling time (VFT) were estimated from continuous DUS signals by a hybrid of Hidden Markov and Support Vector Machine based automated model. The TI and the KI were calculated by using the formula (ICT + IRT)/VET and (ICT + IRT)/VFT respectively.
Results:
The TI was not found to show any significant change from early to late fetuses, nor between normal and abnormal cases. On the other hand, KI was shown to significantly decline in values from early to late normal cases and from normal to abnormal groups. Significant correlation (r = -0.36; p < 0.01) of gestational ages with only KI (not TI) was found in this study.
Conclusion:
Modified TI (KI) may be a useful index to monitor the normal development of fetal myocardial function and identify fetuses with a variety of CHD and non-CHD cases.
