Echocardiographic spectrum of tricuspid atresia.

Standard M-mode and contrast echocardiographic features of 35 patients with tricuspid atresia are reported. These features included a single posteriorly located atrioventricular valve with large excursion, often demonstrating the pattern of systolic prolapse, mitral semilunar valve continuity, and small right ventricular chamber. Left ventricular dimension and left ventricular posterior wall thickness were usually increased. Ventricular septal and posterior wall excursion and percent thickening of the left ventricular posterior wall were in the normal range in most cases. However, fractional shortening of the left ventricular minor diameter was below normal in most patients (26/29, 90%) regardless of the age at presentation. A characteristic and reproducible flow pattern of contrast medium was also observed. After systemic venous injection of indocyanine green, the resultant echoes initially appeared in the left atrium and subsequently, via the mitral valve funnel, appeared in the left ventricular cavity. If a small right ventricular chamber could be recorded, this chamber filled with subsequent systole except in patients with intact ventricular septum. With the use of these M-mode echographic features, along with contrast studies, diagnosis of tricuspid atresia can confidently be established at the bedside and can readily be distinguished from other cyanotic congenital defects.