Morphological study of ventricular septal defect associated with obstruction of the aortic arch among Japanese

This report describes racial differences in the morphology of ventricular septal defects associated with coarctation or interruption of the aortic arch. Twenty-three heart specimens with obstruction of the aortic arch associated with ventricular septal defects collected in southern Japan were studied. Six specimens had an interrupted aortic arch and the remaining 17 cases had coarctation of the aorta. Fifteen cases (65.2% of the total) had malalignment defects with posterior deviation of the conal and/or truncal septum. In contrast to Anderson's report, only one case of perimembranous defect with aortic overriding was seen in our series. These anatomical findings suggest that the majority of ventricular septal defects associated with coarctation or interruption among Japanese is a malalignment defect with left ventricular outflow tract obstruction.