Fully revised and updated for its Fourth Edition, Dr. Josephson's classic text provides a thorough understanding of the mechanisms of cardiac arrhythmias and the therapeutic interventions used to treat arrhythmias. The book details the electrophysiologic methodology required to define the mechanism and site of origin of arrhythmias so that safe and effective therapy can be chosen. Close attention is given to the mechanisms, clinical implications, and limitations of current therapeutic interventions, including drugs, implantable devices, and catheter and surgical ablation. More than 1,100 illustrations clarify the concepts and techniques presented in the text. This edition has a new full-color design. A companion Website offers the fully searchable text with all illustrations.