The material contained in this book was presented at the Boerhaave Course which was held in Leiden, The Netherlands, on May 2 and 3, 1977. It deals with three topics of considerably recent interest, not only to cardiologists and cardiovascular surgeons, but also to embryologists, anatomists and pathologists. Papers on the development and the normal anatomy of the conduction system include a discussion of the continuing controversy as to whether dis crete and anatomically distinct internodal pathways exist in the human heart. These are followed by descriptions of the abnormal anatomy and relation ships of the conduction system in certain complex cardiovascular anomalies. The rather startling discovery that there may be a second, ectopically located and functioning atrioventricular node and common bundle in addition to the usual, but non-functioning one has been of enormous importance in the surgical treatment of certain forms of congenital heart disease. The panel presentations comprising the first four papers on the topic of transposition of the great arteries highlight the widely differing views atld the continuing controversies concerning the nature and pathogenesis of this rela tively common and important anomaly. Descriptions of the special morpho logic features of ventricular septal defect and pulmonary stenosis as they occur in association with transposition are followed by discussions concern ing recent advances in the surgical treatment of transposition, and the com mon and often troublesome postoperative arrhythmias.

Inhalt
I. Conducting System.- A. Normal embryology and anatomy.- 1. Embryology of the conducting system.- 2. The specialized myocardium in the foetal heart.- 3. The morphology of the normal conducting system.- 4. Internodal conduction pathways: specialized or preferential?.- B. Disposition in congenital heart malformations.- 5. The conducting tissues in congenitally complete heart block, a clinico-pathologic correlation in three patients.- 6. The conducting system in hearts with atrioventricular canal malformations.- 7. Conducting tissue in the univentricular heart.- 8. The atrioventricular conduction tissues in congenitally corrected transposition.- II. Transposition of the Great Arteries.- A. Pathogenesis.- 9. Introductory remarks.- 10. The morphogenesis of ventriculo-arterial discordance.- 11. The formal morphogenesis of arterial transposition with special regard to the concept of homology and series formation.- 12. Transposition of the great arteries: controversies concerning the nature and the pathogenesis of the anomaly.- 13. Considerations pertinent to the embryogenesis of transposition.- B. Morphological aspects.- 14. Interventricular communications in transposition of the great arteries.- A. Oppenheimer-Dekker.- 15. Left ventricular outflow tract obstruction in transposition with interventricular communication; anatomical aspects.- C. Clinical aspects.- 16. The surgical treatment of transposition of the great arteries.- 17. Arrhytmias following Mustard's operation for transposition of the great arteries.- III. Ductus Arteriosus.- 18. Ductus arteriosus and prostaglandin.- 19. Ductus arteriosus and indomethacin.- 20. Flow and pressure; the mechanics of closure of the human ductus arteriosus.