Some patients with so called “secundum” atrial septal defect within the oval fossa show a large defect on the echocardiogram, although they do not have all the classical clinical features. Until now, a large atrial septal defect was thought to be characterized by a large shunt (functional defect). Experience indicates, nonetheless, that such large defects in size (anatomical defect) are not always accompanied by large shunts. In order to assess how often the classical clinical features of an atrial septal defect exist, and to investigate whether the surgical indication for closure of the defect are anatomical or functional, we carried out a retrospective study. We evaluated the records of 161 patients, with birth dates from 1973 to 1994 (age between 0 and 21 years), so as to study the classical clinical features (history, physical examination, electrocardiogram, chest X-ray, echo-Doppler studies, cardiac catheterization, surgery). Only patients with an atrial septal defect found in isolation were included.

We discovered that the classical clinical features are often not present when there is a large defect, be it functional or anatomical. The anticipated features are present in roughly two-thirds of the patients. There is also a discrepancy between the anatomical and the functional sizes of the defect. This finding creates a fundamental problem for the future, namely the indications fot closure of atrial septal defects within the oval fossa. Further studies are needed to answer this important question