Dr D. Bruce Foster has been teaching electrocardiography for years to various audiences including interns, residents, nurses, paramedics, and in recent years, physiciana (TM)s assistants. In large measure because of ACLS classes, most of them already had a pretty good understanding of dysrhythmias, so his teaching was primarily focused on the morphologic interpretation of ECGs. Absent a text on the market with which he was happy, he created his own course, and ultimately committed it to paper in the form of the first edition.