The Boerhaave Courses in Cardiology have been held once or twice a year since 1955. For the greater part they were meant for specialists in Cardiology, Pediatrics, and Internal Medicine, who wished to hear about recent advances in Cardiology and in its anatomical and physical basis. For some time the courses reflected mostly the work in Leiden, especially on congenital heart disease, but soon the highly valuable cooperation of other centres was obtained on subjects in which they had more experience. In later years speakers from abroad were also invited and they con­ tributed greatly to the wider scope of the courses. It was thus possible to organize detailed discussions on special subjects by panels of experts for an audience of interested clinical specialists. General reviews were also given for widely varying groups including general practioners and health officers. The special courses were usually given in English and were international in character, while the general courses were given in Dutch. This book reports on a course that united both trends. It was held entirely in English mainly because it was combined with a meeting organized by the Dutch Heart Association and because of the support given by the Secretary of Health who opened this meeting personally and by the European branch of the World Health Organization which was represented by Dr. Pisa.