This book, consisting of two volumes, contains the Proceedings of the 6th International Workshop on Cardiac Arrythmias held in Venice, Italy at the Fondazione Giorgio Cini, on 5-8 October 1999. Over the four days of the meet­ ing, practically all aspects of heart rhythm disorders were addressed and dis­ cussed by internationally renowned experts and by the numerous participants coming from all around the world. Volume 1 - which will be distributed by the international book trade - comprises the contributions of the structured sym­ posia, while Volume 2 contains those of the satellite symposia. This second vol­ ume will exclusively be available to the participants of the workshop. On the whole, I believe the book represents the state of our present knowledge about cardiac arrhythmias and antiarrhythmic therapy. The main topics dealt with in the two volumes include: molecular pathology of cardiac arrhythmias; atrial fibrillation with its different pathophysiological, electrophysiological, clinical and therapeutic aspects; atrial flutter and other supraventricular tachyarrhythmias; ventricular arrhythmias, with particular focus on malignant, idiopathic and uncommon forms; non-antiarrhythmic and antiarrhythmic measures for prevention of sudden death; technological advances and clinical aspects of ICD therapy; modern evaluation of patients with syncope; and, finally, cardiac pacing with practical issues, controversial indications, usefulness of different pacing modes and sites of stimulation and, in particular, usefulness of left ventricular or biventricular pacing for treat­ ment of heart failure. Many individuals have contributed to the realization of this book.