The VIth World Symposium on Cardiac Pacing in Montreal 1979 opened with a course, meant to be an introduction for newcomers and an updating re fresher and link between the various fields of knowledge needed by experienced persons for cardiac pacing. Invited guest lecturers were selected for their world recognized expertise in the individual subjects. This book is a collection of the various presentations on historical, clinical, electrophysiological and technical aspects of cardiac pacing. Together they cover the fundamentals of cardiac stimulation. We hope that this book may become an introductory guide to the field of cardiac pacing and that it may contribute to a better understanding of the pacemaker system and a better treatment of the pacemaker patient. Claude C. Meere Hilbert J. Th. Thalen ACKNOWLEDGEMENT The editors of 'Fundamentals on Cardiac Pacing' acknowledge the under standing and support of their families, during the long nocturnal hours and weekends during which this book was prepared. A special note of appreciation is extended to our secretaries, especially Mrs. Carolyn Gaarenstroom-Arriens and Miss Katrien Schuurman for their 'emergency typing' and Miss Lynn Bacon and Mr. Boudewijn Commandeur from Martinus Nijhoff Publishers, who succeeded in completing the book in time for the Montreal meeting. Only those involved are able to realize the importance of their contribution. CONTRIBUTORS David L. Bowers, B.S.E.E., Vitarel Inc. San Diego, California, U.S.A. Guy Fontaine, M.D., Groupe Hospitalier, Pitie-Salpetriere, Paris, France.