Complete transposition of the great arteries: visualization of left and right outflow tract obstruction by oblique subcostal two-dimensional echocardiography.

Subcostal oblique 2-dimensional echocardiography was performed in 64 infants younger than 2 years with complete transposition of the great arteries (TGA) (situs solitus, concordant atrioventricular and discordant ventriculoarterial connections). All patients examined before cardiac catheterization had a correct diagnosis by 2-dimensional echocardiography using the subcostal oblique views. Twelve patients had associated left ventricular (LV) outflow tract obstruction and 7 had right ventricular (RV) outflow obstruction. The standard parasternal views failed to diagnose obstruction in 1 patients with LV outflow obstruction and 5 with RV outflow obstruction; the subcostal left oblique cut and long axis of the left ventricle visualized all left-sided obstructions, and right-sided obstructions were correctly displayed in 5 of 7 cases using a combination of left oblique and right oblique cuts. Two-dimensional echocardiographic subcostal oblique views allow an excellent definition of the morphologic characteristics of RV and LV outflow tracts in patients with TGA and improve the diagnosis of the outflow obstruction in these malformations.