There are many excellent textbooks that exist in the area of implantable devices for arrhythmia control. Few textbooks, however, provide a case study approach. Collectively, these workbooks provide an approach to problem solving an electrocardiographic interpretation for patients with permanent pacemakers and defibrillators. Volume 1 addresses patients with permanent pacemakersVolume 2 examines interactions between pacemakers and implantable defibrillatorsVolume 3 provides case studies of transtelephonic pacemakers electrocardiographyVolume 4 provides more pacemaker and implantable defibrillator troubleshooting casesThis volume takes a case-orientated approach, providing a diverse series of problems on a broad range of topics related to implantable defibrillators. The cases are divided into easy, moderate and complex according