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.

Sustained maternal hyperoxygenation improves aortic arch dimensions in fetuses with coarctation.

The aim was to investigate the impact of maternal hyperoxygenation (HO) on cardiac dimensions in fetuses with isolated Coarctation (CoA). Fetal echocardiography was performed serially in 48 fetuses with CoA and gestation age matched normal fetues. The Z-scores for the mitral valve (MV), tricuspid valve (TV), aortic valve (AV), ascending aorta (AAo), isthmus, pulmonary valve (PV), main pulmonary artery (MPA), and descending aorta (DAo) were measured and compared among normal fetuses, CoA fetuses with oxygen and CoA fetuses with air. In the group with oxygen, 6 L/min oxygen was administered to the mother using a face mask. Regression analyses were performed to identify potential factors for HO outcome. The left heart dimension Z-scores increased gradually during HO therapy periods, especially at 4 weeks after oxygen therapy (P < 0.05). As for the case group with air, the left heart dimension remained unchanged. The duration of HO was associated with aortic arch Z-scores (adjusted R2 = 0.199, 0.60 for AAO and isthmus, respectively). Sustained maternal middle-flow oxygenation can be safely used to improve left heart dimensions in fetuses with isolated CoA. The duration of HO were associated with treatment outcome. These findings may provide useful information for developing novel treatment strategies.