Focusing on anatomy and procedural strategy for atrial fibrillation and ventricular tachycardia, this atlas uses pictures and schematic diagrams to show how to use intracardiac echo (ICE) to assess anatomy, guide ablation, and prevent complications during interventional procedures, pulmonary vein stenosis, and embolic events. The authors review the state of the art and background support in the use of ICE in interventional electrophysiology procedures and the anatomy of both the atrial and ventricular chambers. They discuss innovative indications in the EP laboratory, future technologies such as 3-D echocardiography, and the integration of ICE with other types of imaging technology.