Pulmonary Atresia With Intact Ventricular Septum

Pulmonary atresia with intact ventricular septum accounts for less than 3% of all congenital heart defects (Grossfeld et al., 1997).

Chitayat et al. (1992) reported 2 sisters with hypoplastic right heart and pulmonary atresia. The first sib was found in the newborn period to have this abnormality. An attempt at surgical repair was unsuccessful. In the next pregnancy, fetal echocardiography at 22 weeks of gestation demonstrated the same cardiac abnormalities, which were confirmed at autopsy in the fetus. No other malformations were found in either case and no other relatives were affected.

Grossfeld et al. (1997) reported 2 first cousins with pulmonary atresia and intact ventricular septum. The first had a severely hypoplastic right ventricle and tricuspid valve and a restrictive atrial septal defect. She died at age 12 days. The patient's maternal aunt delivered a son with congenital heart disease 23 years earlier. At that time, pulmonary atresia with intact ventricular septum, hypoplastic tricuspid valve and right ventricle, and patent ductus arteriosus were noted. That patient died at age 5 months. Grossfeld et al. (1997) suggested autosomal dominant inheritance with incomplete penetrance.

De Stefano et al. (2008) reported monozygotic twin sisters with pulmonary valve atresia and intact ventricular septum. The girls died of respiratory failure at age 3 and 7 days, respectively. Echocardiography and postmortem examination of both patients showed pulmonary valve atresia with 3 fused valves and no identifiable lumen. There was generalized cardiomegaly, right atrial dilatation, right ventricular hypertrophy, and small right ventricular chambers. The tricuspid valves were dysplastic with 2 thick leaflets attached to the right ventricular endocardium. One twin also had aortic stenosis with a bicuspid aortic valve and thick, dysplastic leaflets. Molecular analysis identified a biallelic 55-kb deletion of chromosome 20q13.12 in both girls. The unaffected nonconsanguineous parents were each heterozygous for 1 of the deletions.