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 topics to be edited in book-form. The final result is here. We hope, it will be of value for both to the adult and pediatric cardiologist and other colleagues, who have to undertake the care of this group of patients, whose management poses such unique problems. J.H. G.S. ix 1. The problem - an overVIew JANE SOMERVILLE The subject of grown-up congenital heart disease is currently and correctly attracting attention in the world. Surgical treatment for congenital heart disease (C.H.D) has evolved through the last 40 years, starting with the attempts by Blalock and Brock to palliate, to the current refined technical virtuoso repairs of the most complex in infancy.