The differential diagnosis of levo-transposed or malposed aorta. An angiocardiographic study.

The levo-transposed aorta has previously been considered diagnostic of corrected transposition of the great arteries and hence ventricular inversion in situs solitus. Increasing experience with conotruncal abnormalities has shown that an abnormally leftward aorta may be found in patients with normally related ventricles (D-ventricular loop) and hemodynamically complete transposition of the great arteries; anatomically corrected L-malposition of the great arteries; and rarely in patients with D-ventricular loop, double outlet right and left ventricles. Thus the levo-positioned aorta should suggest a wider spectrum of cardiovascular abnormalities than previously thought. The specific angiocardiographic features of levo-transposition, anatomically corrected malpositions, and D-ventricular loop with levo-transposed aorta are presented in detail; and their differential diagnosis from the very uncommon D-loop, double outlet right and left ventricles with an L-malposed aorta is considered. The role of selective biplane angiocardiography in the assessment of these conotruncal abnormalities is stressed.