Aortic Coarctation: A Comprehensive Analysis of Shape, Size, and Contractility of the Fetal Heart

Background: An integrated assessment of the size and shape of the 4-chamber view (4-CV) and right and left ventricles (RV and LV) as well as the function of the RV and LV in fetuses with coarctation of the aorta (CoA) has not yet been conducted. Objectives: We evaluated the size and shape of the 4-CV, RV, and LV, and function of the RV and LV, to identify a profile for fetuses with CoA when compared to a control population. Methods: 50 CoA fetuses were compared to 200 controls. This was a retrospective case series comparing the 4-CV of CoA fetuses and controls. The 4-CV end-diastolic area, length, width, and sphericity index were measured to determine the configuration of the 4-CV. Speckle-tracking analysis was used to compute the RV and LV end-diastolic area, length, 24-segment sphericity index, 24-segment transverse width, and the following functional parameters: (1) fractional area change; (2) global, lateral, and septal strain; (3) basal-apical, lateral, and septal annular displacement and fractional shortening; and (4) 24-segment transverse width fractional shortening. Using 5 and 95% reference intervals, the CoA fetal measurements were classified; from these, the odds ratio was computed between the fetuses with CoA and the controls. p < 0.05 was considered significant. Results: In fetuses with CoA, the 4-CV was spherical in shape, increased in area and width, and decreased in length. Abnormal CoA sphericity indices reflected a flatter LV and a more spherical RV. The LV area, length, and width, and RV length were decreased. The transverse width of the RV was increased. RV and LV global, longitudinal, and transverse contractility were depressed. Conclusions: The results demonstrate previously unappreciated differences in the shape, size, and function of the heart in fetuses with CoA. These differences may assist examiners in identifying fetuses with CoA.