Echocardiographic spectrum of congenitally unguarded tricuspid valve orifice and patent right ventricular outflow tract.

A series of nine consecutive patients with unguarded tricuspid valve orifice as a result of partial or complete agenesis of the valvar tissue and patent right ventricular outflow tract is reported. Clinical manifestations were cyanosis, severe right ventricular failure and incidental echocardiographic detection in a young patient with dilated cardiomyopathy. This series contains the oldest reported patient with this malady, who was misdiagnosed as portal hypertension for 10 years. This study, with possibly the largest number of patients reported so far, sheds some light on the natural history of a rare entity.