This book provides a concise overview of cardiac electrophysiology for cardiologists who are not electrophysiologists and for allied cardiovascular professionals, cardiology registrars and fellows who are new to the field. It familiarises them with the main procedures performed in the electrophysiology laboratory. Emphasis is placed on helping the reader develop a core understanding of how data is collected and interpreted in the electrophysiology laboratory, and how this is used to guide ablation for the commonest arrhythmias including AV nodal re-entry tachycardia, accessory pathways, atrial fibrillation and ventricular arrhythmias. Decoding Cardiac Electrophysiology: Understanding the Techniques and Defining the Jargon will translate some of the technical terminology and data frequently used by electrophysiologists into terms and concepts familiar to the wider cardiovascular community. This includes the interpretation of electrograms and 3D electro-anatomicalmaps of common arrhythmias.  Accordingly, it offers a valuable resource for all non-electrophysiologists seeking a guide to the topic and for electrophysiology trainees establishing their core knowledge and skills in the field.  The aim is that this should be the first book anyone new to the field should choose to read.