The interatrial septal defect is an anatomically well known entity. Louis (1826), Ecker (1839) and Cruveilhier (1852) stated the characteristic anatomic findings in the heart in the presence of a large interatrial communication: the enormous increase in the volume of the heart, which is due to dilatation and hypertrophy of the right side; the marked dilatation of the pulmonary artery and its branches, and the relative smallness of the left ventricle. Rokitansky's classic monograph on septal defects (1875) gives many examples of this malformation as well as embryologic explanations. Ecker, a pupil of Rokitansky, also attempted to correlate the anatomic picture with the clinical picture. Of the modern clinical contributions there may be mentioned especially the articles by Hoefler, Lutembacher, Müller, Assmann, Abbott and Weiss and Dressler and Roesler.1 An extensive clinical study with a complete review of the literature, however, does not exist.
The detailed anatomic study of