Proceedings of a congress serve the purpose to provide the reader with the latest know­ ledge in the specific field. They present at least for a limited time period a reference book that allows rapid access to the latest information for the medical profession and for an ongoing of future research. This volume is addressed not only to the participants of the VIIth World Symposium on Cardiac Pacing but to everybody involved in diagnostic and therapeutic cardiac stimula­ tion. The experience has shown that proceedings of conferences of comparable size are usually published with a considerable time delay limiting its value as a source of prime information. The editors of this volume decided therefore, that their most important task was to guarantee the actuality of the publication. Even if it seems desirable to include as many presentations of a conference as possible, the large number of excellent presentations at the VIIth World Symposium on Cardiac Pacing, 337 oral presentations and 236 posters, could not be published within an accepta­ ble time period. The experience from previous conferences has shown that a book which includes all the papers can only be edited with a large delay, which reduces the value and actuality of the information.