Hypoplastic left heart syndrome: natural history in a geographically defined population.

Advances in surgical treatment of hypoplastic left heart syndrome with the Norwood procedure and cardiac transplantation have made essential the understanding of the natural history of hypoplastic left heart syndrome. In a geographically defined population, we ascertained the prevalence of hypoplastic left heart syndrome in children born in Oregon from 1971 through 1986. Clinical and anatomic data were extracted from the charts of the 98 affected children and the survival rate was calculated. Hypoplastic left heart syndrome occurred in 0.162 per 1000 live births in Oregon during this period. No syndrome complex was prevalent and 84% were free of other congenital malformations. However, there was an increased occurrence of congenital heart defects in first-degree relatives of probands with hypoplastic left heart syndrome. Of the affected children 15 +/- 4% died on the first day of life, 70 +/- 5% died within the first week, and 91 +/- 3% died within 30 days. No secular change in survival occurred during the study. Palliation with the Norwood procedure was performed in 20 children. Although survival was significantly improved with this surgery (P = .01), the effect was observed principally through 30 days of life and only one of these children remains alive. Hypoplastic left heart syndrome is a lethal congenital heart defect in children and poses management and ethical dilemmas.