Radiological Aspects of Pulmonary Atresia with Intact Ventricular Septum.

The clinical, pathological, and electrocardiographic findings in congenital pulmonary atresia with intact septum have been reviewed recently by Elliott, Adams, and Edwards (1963). Among their 12 cases, the x-ray examinations on 10 were available for this study. The most characteristic appearance on the frontal chest radiograph in pulmonary atresia is the diminution in the size of the pulmonary vasculature. All 10 cases in this series showed moderate or great decrease in the pulmonary vasculature. Admittedly, the newborn child caught in the extreme depth of inspiration on a good cry may give the appearance of having decreased pulmonary vasculature but not to the degree seen in any of these children. Associated with the decreased pulmonary vasculature one usually finds a degree of cardiomegaly. It is noteworthy that most of these 10 infants did not exhibit much cardiomegaly. The only case in which cardiomegaly was pronounced was that of an infant who, at necropsy, was found to have a large right ventricular cavity. The configuration of the heart in most cases of pulmonary atresia is fairly typical (Fig. 1). The right cardiac border may show two convex curves. Superiorly one may note a prominent convex soft tissue density caused by an enlarged prominent aorta which displaces the superior vena cava to the right. The inferior convex density is the result of an enlarged right atrium. The superior portion of the left cardiac border in the region of the pulmonary artery segment is usually concave, which reflects the absence or underdevelopment of the main pulmonary artery. This region was concave, or at best flattened, in all 10 cases. The lower left cardiac border, however, shows a prominent convexity which appears to point more laterally than inferiorly: this prominence can be attributed to the enlarged left ventricular chamber. Furthermore, oblique and lateral views of the heart usually show evidence of left atrial enlargement.