Pulmonary vascular disease in children with congenital cardiovascular malformations. Etiologic considerations.

A detailed clinical analysis of 16 patients with various forms of congenital cardiac malformations with the potential for large left-to-right shunts who developed extreme pulmonary hypertension in infancy and early childhood has been carried out. The study plan was to include only patients with sufficiently long follow up to allow analysis of their course in both the prepubescent and postpubescent periods. In early life these patients were all characterized by lack of evidence for significant development of the expected left-to-right shunt indicating inappropriate maturation of their pulmonary vascular circulation. Throughout all phases of their life, they were significantly polycythemic in comparison with a control group but this polycythemia, representative of peripheral systemic hypoxemia, increased markedly with the acquisition of puberty in all patients. These two findings indicate both an early abnormality, suggestively primary, of the pulmonary vasculature and a late progression of the disease associated with pubertal maturation.