[Membranous tricuspid atresia with right ventricular dysplasia and absent pulmonary valve: echocardiographic findings in three cases].

Membranous tricuspid atresia with right ventricular dysplasia and absent pulmonary valve is a very rare complex, and a unique type of tricuspid atresia. Three cases with this condition were presented with the echocardiographic evaluation. Two-dimensional echocardiography was performed in all patients, pulsed Doppler echocardiography in two, and contrast echocardiography in two patients. The echocardiographic findings characteristic of this complex were as follows: In the four chamber view, the interatrial and interventricular septa were aligned, and tricuspid valve atresia was of the membranous type. In the four-chamber view, the right ventricular wall was thin, irregular in shape, and it protruded aneurysmally into the left ventricular outflow tract. With systemic venous contrast echocardiography, the right ventricular cavity was opacified with contrast, four to five cardiac cycles after the appearance of contrast in the left ventricle. With pulsed Doppler echocardiography at the main pulmonary artery, antegrade flow was observed in ventricular systole, and retrograde flow in diastole. We conclude that these echocardiographic findings are useful in recognizing the morphology and hemodynamics of this complex.