Left ventricle inflow and outflow tract angle in normal fetuses

Area of Science:

• Fetal Cardiology
• Medical Imaging
• Anatomy

Background:

• Aortic elasticity is impaired in fetuses with congenital heart disease.
• Left ventricle outflow tract orientation impacts ascending aorta blood flow.

Purpose of the Study:

• To determine the normal range of the left ventricle inflow and outflow tract angle (LIOA) in healthy fetuses.
• To investigate the relationship between LIOA and fetal growth and cardiac dimensions.

Main Methods:

• Prospective study of 668 fetuses.
• Two-line method used for LIOA measurement at the inflow/outflow tract view.
• Pearson's correlation coefficient assessed associations with estimated fetal weight (EFW), cardiac axis, and valve diameters (AV, PAV, MV, TV).

Main Results:

• The mean LIOA was 44° ± 7.5°.
• No significant differences in LIOA were found across gestational ages.
• A mild positive correlation was observed between LIOA and cardiac axis.
• No significant associations were found between LIOA and EFW or valve diameters.

Conclusions:

• The LIOA is stable during the mid-third trimester in normal fetuses.
• A mild positive correlation exists between LIOA and cardiac axis in healthy fetuses.