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Updated: May 10, 2026
Fetal Echocardiography and Pulsed-wave Doppler Ultrasound in a Rabbit Model of Intrauterine Growth Restriction
Published on: June 29, 2013
Myocardial velocities, dynamics of the septum primum, and placental dysfunction in fetuses with growth restriction
Alexandre Antonio Naujorks1, Paulo Zielinsky, Caroline Klein
1Fetal Cardiology Unit, Instituto de Cardiologia/Fundação Universitária de Cardiologia, Porto Alegre, Rio Grande do Sul, Brazil.
Insights
In fetuses with intrauterine growth restriction (IUGR), reduced septal mobility indicates higher left atrial pressure, correlating with diastolic dysfunction. Fetal myocardial tissue Doppler (MTD) can assess placental dysfunction severity.
Area of Science:
- Perinatology
- Fetal Cardiology
- Reproductive Medicine
Background:
- Diastolic dysfunction is a potential complication in fetuses with intrauterine growth restriction (IUGR).
- Myocardial tissue Doppler (MTD) can assess fetal diastolic function.
- Reduced excursion index of the septum primum (EISP) in IUGR fetuses over 30 weeks suggests elevated left atrial pressure.
Purpose of the Study:
- To investigate the relationship between left atrial pressure, diastolic function, and placental dysfunction in IUGR fetuses.
- To evaluate the utility of EISP and MTD-derived E'/A' ratios in assessing fetal well-being in IUGR.
Main Methods:
- A cohort of 14 fetuses with IUGR underwent MTD examination at the left ventricle (LV), interventricular septum (IVS), and right ventricle (RV) to determine E'/A' ratios.
- EISP was calculated as the ratio of maximal septal excursion into the left atrium during diastole to the maximal left atrial diastolic diameter.
- Conventional Doppler assessed mitral and tricuspid flows; Pearson's correlation test analyzed parameter relationships.
Main Results:
- Positive correlations were found between UARI and RV E'/A' (r=0.63, P=.02), IVS E'/A' (r=0.59, P=.03), and LV E'/A' (r=0.41, P=.15).
- A negative correlation existed between EISP and IVS E'/A' (r=-0.58, P=.03), while a positive correlation was seen with LV E'/A' (r=0.49, P=.08).
- A weak negative correlation was observed at the RV position (r=-0.32, P=.26).
Conclusions:
- Elevated left atrial pressure in IUGR fetuses, indicated by decreased septal mobility, is associated with increased early and late diastolic myocardial velocity ratios.
- Septal E'/A' ratios demonstrated a correlation with placental dysfunction.
- Fetal MTD is a valuable tool for assessing the severity of placental dysfunction and fetal distress in IUGR.
Introduction:
Diastolic dysfunction may occur in fetuses with intrauterine growth restriction (IUGR) and may be assessed by myocardial tissue Doppler (MTD). We previously have shown that excursion index of the septum primum (EISP) is reduced in IUGR fetuses over 30 weeks because of a higher left atrial pressure.
Patients, Setting, And Design:
The sample was made up of 14 fetuses with IUGR. MTD examination was carried out with the sample volume placed at the basal lateral wall of the left ventricle (LV), interventricular septum (IVS), and free wall of the right ventricle (RV) to determine E'/A' ratios. EISP was calculated as the ratio between the maximal excursion of the septum primum into the left atrium during diastole and the maximal diastolic diameter of the left atrium. Mitral and tricuspid flows were assessed by the conventional Doppler method.
Outcome Measures:
Pearson's correlation test was used to analyze the correlations between the parameters.
Results:
A positive correlation was observed between UARI and E'/A' ratios for RV (r = 0.63, P = .02), IVS (r = 0.59, P = .03), and LV (r = 0.41, P = .15). There was a negative correlation between EISP and IVS E'/A' ratios (r = -0.58, P = .03), and a positive correlation for LV (r = 0.49, P = .08). At the RV position, a weak negative correlation was observed (r = -0.32, P = .26).
Conclusions:
A higher left atrial pressure in fetuses with IUGR, indicated by the lower mobility of the septum primum, is accompanied by higher ratios between early and late diastolic myocardial velocities. Placental dysfunction was correlated to septal E'/A' ratios. Fetal MTD can be a useful method to assess severity of placental dysfunction and fetal distress.
