In a series of 1,000 cases of congenital heart disease Abbott1 included 12 cases in which aortic atresia was the primary lesion and 2 additional cases in which it was associated with another cardiac defect. In 1 of these cases a systolic murmur was noted, in 1 a continuous murmur and in 8 cyanosis. Roberts2 found 9 cases of this anomaly alone and 6 additional cases in which it was associated with other congenital cardiac defects. He reported another case, that of a second-born twin who had severe cyanosis and dyspnea and who died twenty hours after birth; the first-born twin, who died immediately after birth, had a normal heart. In this group of cases Roberts correlated the duration of life with the size of the interatrial aperture. Three of the same cases were included in a review by Lippincott,3 who added the report of a case