Fetal Cardiac Deformation in Persistent Left-Sided Superior Vena Cava and Suspected Coarctation of the Aorta.

Prenatal prediction of critical coarctation of the aorta remains challenging. Fetal echocardiography in isolated persistent left-sided superior vena cava (IP L-SVC), a benign variant, can mimic suspected coarctation with shared right-to-left ventricular size discrepancy. We sought to describe cardiac deformation in fetuses with IP L-SVC and compare to those with suspected coarctation. We hypothesized that cardiac deformation as measured by global longitudinal strain (GLS) could differentiate fetuses with coarctation from IP L-SVC. This is a single-center, retrospective study of fetuses with IP L-SVC and suspected coarctation. Fetal cardiac deformation analysis was performed using a vendor non-specific software. The primary variable was GLS. Secondary variables were left ventricular ejection fraction, left ventricular end-systolic volume, and left ventricular end-diastolic volume (LVEDV). Mean LVEDV z-score was determined. Interrater reliability was performed. Baseline measures of GLS were performed using a cohort of normal fetuses. Ninety fetuses were analyzed (IP L-SVC n=28, suspected coarctation n=30, normal n=32). Seventeen required surgical repair for coarctation. Fetuses with IP L-SVC and suspected coarctation had lower GLS (p <0.001) and smaller left ventricular size compared to normal (p<0.001). Fetuses who required surgical repair for coarctation of the aorta had the lowest LVEDV. Interrater reliability was poor to moderate. Our study is the first to date that examines strain in fetuses with IP L-SVC compared to suspected coarctation of the aorta. Cardiac deformation in fetuses with IP L-SVC was indistinguishable from fetuses with suspected coarctation of the aorta. GLS proved a poor predictor of postnatal surgical repair in isolation.