This book presents the features of Wolff-Parkinson-White and other preexcitation syndromes with detailed discussion of the management and treatment of these patients. Catheter ablation has become a curative first-line treatment for circus movement tachycardias involving accessory pathway conduction. However, diagnostic and interventional challenges may be associated with anatomically and electrophysiologically complex single accessory pathway conduction, multiple accessory pathways, accessory pathways with other coexistent tachycardias, including atrioventricular nodal reentrant tachycardia and atrial tachycardias, and accessory pathways with coexistent congenital heart disease. The complexity involved requires a thorough theoretical and practical knowledge for performing unequivocally conclusive/meaningful electrophysiological testing and successful catheter ablation.