Comprehensive Evaluation of Fetal Cardiac Ventricular Widths and Ratios Using a 24‐Segment Speckle Tracking Technique

Introduction This study was conducted to evaluate the 24‐segment transverse widths of the right and left ventricles distributed from the base to the apex of the ventricular chambers and compute the right ventricular (RV)/left ventricular (LV) ratios for each segment. Methods Two hundred control fetuses were examined between 20 and 40 weeks’ gestation. Using offline speckle‐tracking software, the 24 end‐diastolic transverse widths were computed and the RV/LV ratios were regressed against 7 independent variables related to the size, weight, and age of the fetuses. Five fetuses with coarctation of the aorta and 5 fetuses with pulmonary stenosis were examined to exemplify the utility of these measurements. Findings The 24‐segment transverse widths were associated with changes in fetal size, weight, and age. Regression equations were developed to describe these changes with R 2 values between .5 and .82. The measurements were normally distributed (Shapiro‐Wilk > 0.5). The RV/LV ratio for the 24 segments did not strongly correlate ( R 2 = .001 to –.2) with fetal size, weight, or gestational age. Fetuses with coarctation of the aorta and pulmonary stenosis demonstrated characteristic changes in the 24‐segment transverse widths and the RV/LV ratios in the basal (segments 1–8), mid (segments 9–16) and apical (segments 17–24) sections of the ventricles. Conclusions The 24‐segment transverse widths of the right and left ventricles and the RV/LV ratios provide a comprehensive method to examine the width of the ventricular chambers.