ABSTRACT
Introduction Congenital tricuspid valve malformations, which include apical displacement of the tricuspid valve (Ebstein malformation) or dysplasia, are rare forms of structural heart disease that predominantly lead to tricuspid regurgitation. The postnatal incidence has been estimated at approximately 50-100 per 1 million live births, which comprises up to 1% of congenital heart disease.1-3 However, the prenatal incidence has been noted to be substantially higher, comprising up to 8% of congenital heart disease.4 Ebstein malformation or tricuspid valve dysplasia that leads to severe tricuspid regurgitation is poorly tolerated in the fetus, with the development of cardiomegaly, ventricular dysfunction, and hydrops. Perinatal mortality, including fetal demise or neonatal death, was reported to be as high as 45% in a recent, large contemporary series across North America.5 Advances in fetal echocardiography have led to the prenatal diagnosis of more mild forms of disease, with mild or less tricuspid regurgitation. Such patients are uncommonly affected early in life and may remain asymptomatic until adolescence or adulthood.
