The primary defect is severe hypoplasia of the myocardium of the right
ventricle. The thin parchment like right ventricle has poor or absent
contractility and therefore dilates.
- Markedly dilated right
atrium.
- Moderately dilated right
ventricle.
- Ventricular septum has a
normal thickness but moves paradoxically during systole (1).
- Tricuspid valve is dysplastic
or dilated resulting in marked tricuspid regurgitation (and subsequent
right atrial enlargement).
- Ebstein's
anomaly which is often associated with hypoplasia of the myocardium
and right atrial dilatation. Pulmonary hypoplasia due to compression of
the lung from the markedly enlarged heart may be seen in both conditions.
The prognosis is related to the degree of right atrial dilatation and the
cardiac compromise. Some cases have been reported to survive into adulthood.
- Benson CB, Brown DL, Roberts
DJ. Uhl's anomaly of the heart mimicking Ebsteins anomaly in utero. J
Ultrasound Med 1995;14:781-783.