In May 1990, the First International Symposium on Congenital Heart Disease in Adolescents and Adults was organized in Rotterdam. During these three days' Symposium an overview of the many new problems facing the adult and pediatric cardiologist as well as the cardiac surgeon in this rapidly increasing subgroup of the adolescent and adult cardiac population was given. Chal lenges, controversies, uncertainties and questions were presented and discussed with great enthusiasm. We are greatful that most speakers who participated in this symposium, were willing to write a chapter on their presented...