Radiologic and Angiocardiographic Findings in Complete Transposition of the Great Vessels with Left Ventricular Outflow Tract Obstruction

The typical radiologic and angiocardiographic features of complete transposition of the great vessels with the aort a arising anteriorly from the anatomic and functional right vent ricle, and the pulmonary artery post eriorly from the anat omic and fun ctional left ventricle, are well known (1–6). With the rapid st rides which have taken place in the surgical correction of this anomaly, recognition of obstruction to the outflow tract of the left vent ricle has become increasingly important. A previous report dealt with the pathological findin gs in 23 specimens with this condition (7). Both valvular and subvalvular types of left vent ricular outflow tract obstruction were identified (Fig. 1). The subvalvular va riety exhibited three different appearances: (a) a fibromuscular tunnel found only with a ventricular sept al defect, (b) a fibrous ring or diaphragm found with and without a vent ricular septal defect, and (c) subvalvular muscular narrowing caused by bul ging of the ventricular septum into the cav...