Uhl's anomaly: Clinical spectrum and pathophysiology

Abstract

A 28 year-old woman from Afghanistan was referred for prenatal evaluation. She and her husband were consanguineous and had a previous female baby with a rare congenital cardiac defect that consisted of Uhl's anomaly, Ebstein's malformation and pulmonary atresia. The child died after the first palliative step towards a Fontan circulation. A fetal echocardiogram performed at 18 + 2 weeks' gestation showed distinctive right-sided cardiac abnormalities similar to those found in their previous daughter. A dilated, extremely thin walled right ventricle (RV) with poor systolic function was found with a markedly dysplastic tricuspid valve (Fig. 1A, Video 1). There appeared only to be a rudimentary anterior tricuspid valve leaflet. The tricuspid orifice was larger than the mitral valve annulus, 4.9 mm (Z-score +1.5) and 3.6 mm (Z-score -1.5) respectively [1] and free regurgitation through the rudimentary tricuspid valve was present. The oval fossa was wide open with right to left shunting over it (Fig. 1A–B, Video 2). The pulmonary valve annulus diameter was small (2.3 mm, Z-score -0.9) and the pulmonary arteries were underdeveloped (Fig. 1E). The left side of the heart appeared structurally normal (Fig. 1A–C) with normal aortic annulus dimension (3.0 mm, Z-score +2.9). No prograde flow could be detected over