Many caregivers working in the field of medicine find that one of the best ways to learn is by working through clinical cases, and for many individuals it's even more helpful to work through the examples as "unknowns." This is especially true in the arena of implantable cardiac devices. In an effort to provide this experience, experts from the Mayo Clinic, Rochester, Minnesota, have produced two volumes of case studies that encompass variations of normal and abnormal function of pacemakers, ICDs, and CRT devices. The texts have been written collaboratively by five clinicians with differing backgrounds in an effort to present the cases in such a way that they are applicable to a variety of caregivers. Cases for this book were selected based on clinical relevance and their usefulness for illustrating general principles, practical tips, or interesting findings in device practice, with the goal of advancing general concepts in device management. The first volume includes introductory and intermediate cases. The second volume includes additional intermediate cases as well as advanced/multipart cases.