Clinical features of aortic arch anomaly with malalignment ventricular septal defect.

The clinical features and outcome after various surgical procedures on 9 patients with coarctation or interruption of the aortic arch and malalignment ventricular septal defect (group 1) were compared with those of 9 patients with the arch anomaly without malalignment ventricular septal defect (group 2). Cardiomegaly and metabolic acidosis were prominent in group 1. Five of the 9 patients in group 1 died in the immediate postoperative period (56% mortality), but no operative deaths occurred among 8 patients in group 2 (p less than 0.01). The ratio of left ventricular outflow tract to ascending aortic diameter was 0.59 +/- 0.09 in group 1 and 1.03 +/- 0.11 in group 2 (p less than 0.01). Three of 4 patients with a ratio of less than 0.6 died, but no operative deaths occurred among the 6 patients who had a palliative operation and in whom the ratio was more than 0.6. These data suggest that left ventricular outflow tract obstruction is critical when the ratio of left ventricular outflow tract to ascending aortic diameter is 0.6 or less. The presence of severe left ventricular outflow tract obstruction necessitates modification of the present surgical strategy.