A Practical Guide to Cardiac Pacing, Sixth Edition, is written to acquaint the reader with basic pacemaker principles and terminology. We have always viewed this book as a bridge between the beginners in pacing, or general cardiologists, and the engineers involved in designing pacemakers and electrophysiologists doing advanced pacemaker work. Every effort has been made to keep the text basic and some discussions are deliberately simplified to provide a framework for understanding pacemakers..