Fetal Doppler echocardiographic diagnosis and successful steroid therapy of Luciani-Wenckebach phenomenon and endocardial fibroelastosis related to maternal anti-Ro and anti-La antibodies.

Background: Complete fetal heart block (HB) and endocardial fibroelastosis (EFE) are known to be associated with maternal anti-Ro and anti-La antibodies. Complete fetal HB is irreversible.

Objectives: We sought to (1) assess the value of the superior vena cava/ascending aorta Doppler approach in the early detection of abnormal delay in the fetal atrioventricular (AV) time of conduction, before appearance of complete fetal HB; and (2) report the effect of prenatal steroid therapy on EFE, HB, or both.

Results: The clinical history, echocardiographic, and Doppler investigations of 3 fetuses and children born to mothers positive for anti-Ro and anti-La antibodies are reported. Two fetuses presented with EFE either isolated (29 weeks) or associated with AV block (25 weeks). In this last case, the superior vena cava/ascending aorta approach allowed the identification of a Luciani-Wenckebach phenomenon. In a third fetus, 2:1 AV block was noted at 23 weeks of gestation. Dexamethasone (4 mg/day) was administered to all 3 patients. Complete regression of the EFE and conduction abnormalities was documented in all cases.

Conclusion: Early prenatal detection of abnormal delay in fetal AV time conduction is possible with the Doppler superior vena cava/ascending aorta approach. Steroid therapy can cure fetal EFE and AV conduction delays associated with maternal anti-Ro and anti-La antibodies.