Sustained Chronic Maternal Hyperoxygenation Increases Myocardial Deformation in Fetuses with a Small Aortic Isthmus at Risk for Coarctation.

BACKGROUND: We aimed to assess differences in myocardial deformation in fetuses at risk for coarctation (CoA) and the effects of maternal hyperoxygenation on deformation.

METHODS: Fetal echocardiography and velocity vector imaging were performed prospectively and serially in 48 fetuses with a small aortic isthmus and 48 gestation age-matched normal fetuses. Fetuses with a small aortic isthmus were randomly divided into two groups: one group with and the other group without maternal supplemental oxygen administration. The strain (S) and strain rate (SR) in the left ventricle (LV) and right ventricle (RV) were measured and compared between the groups. Regression analyses were performed to identify potential factors associated with myocardial deformation.

RESULTS: Compared with normal fetuses, fetuses with a small aortic isthmus exhibited a lower S and SR at baseline. A negative correlation was found between aortic isthmus velocity-time integrals and S and SR at baseline (P < .05). In the group that received supplemental oxygen therapy, the S and SR in both the LV and RV increased as a function of time, especially 4 weeks after the initiation of oxygen therapy (P < .05). The duration of oxygen therapy and increased combined cardiac index were associated with increased myocardial deformation (P < .05).

CONCLUSIONS: Myocardial deformation appears abnormal in those at risk for CoA beginning in utero, and chronic oxygen therapy appears to increase deformation measures. These findings may improve patient counseling and perinatal management.