Pulmonary Atresia with Intact Ventricular Septum

Abstract

Although congenital pulmonary atresia with an intact ventricular septum is an uncommon malformation, its recognition is important because the results of surgical treatment may be favourable in some cases. Functionally, this entity belongs to a group of congenital malformations each having obstruction to pulmonary flow. This group includes severe pulmonary stenosis, tricuspid atresia, pulmonary atresia with a ventricular septal defect, and the origin of the aorta and pulmonary trunk from the right ventricle with severe pulmonary-stenosis.In these congenital cardiac malformations, the fundamental functional problem and the clinical picture are determined by obstruction to pulmonary blood flow in the right side of the heart. As a result of this obstruction, right-to-left shunts of varying degrees occur at different sites depending on the type of intracardiac communication present. This hlmodynamic phenomenon is usually manifested clinically by early intense cyanosis. Congestive heart failure occurs in most cases, and early death is common. Since the results of surgical treatment vary greatly in cases of these types of cardiac malformation, immediate and proper diagnosis is essential (Benton et al., 1962). Greenwold et al. (1956) made a study of 12 cases of pulmonary atresia with an intact ventricular septum and divided them into two groups on the basis of the size of the right ventricle. The first group included 6 cases in which the right ventricle was minute or small, and the second group included 6 in which it was of normal size or large. Keith, Rowe, and Vlad (1958) described the pathological findings in 46 cases: the right ventricle was of normal size or large in only 15 per cent of the 46 cases. Davignon et al. (1961) correlated the clinical and pathological findings in 20 cases: several of these were previously included in the report by Greenwold et al. (1956). MATERIAL This report is based on the anatomical, clinical, and electrocardiographic aspects of 12 cases of pulmonary atresia with an anatomical or functionally intact ventricular septum, which were observed at the University of Minnesota Hospitals. In an article to be published, Kieffer and Carey (1963) will consider the radiographic aspects of these cases. Other examples of obstructive lesions of the right side of the heart, such as tricuspid atresia, were not included in our study. ANATOMICAL OBSERVATIONSThe right ventricle was minute in 3 cases, small in 6, of normal size in 2, and large in 1 case.Pulmonary Valve and Arteries. The pulmonary valve had no opening but was represented by a fibrous membrane or diaphragm (Fig. 1). Radiating from the centre on the arterial side of the diaphragm were three equidistant ridges or raphes which extended to the wall of the pulmonary trunk.