Electrical therapy of the heart has rapidly evolved over recent years with the development of the cardiac implantable defibrillator and the application of the cardiac resynchronization therapy to improve performance of the congestive failed heart. There is an impressive amount of literature produced to assess the efficacy and effectiveness of the electrical therapy. New technology is continuously introduced into the market for the treatment of electrical heart disease with optimized performance and implemented design, with approximately 600,000 new pacemakers implanted each year. Attention of the electrophysiology community has mainly focused on the biomedical aspects of electrical therapy, but the psychological, emotional, social and cognitive aspects of the implantable devices has been largely overlooked. Health-related quality of life (QoL) and, to a lesser extent, psychological disorders, i.e. anxiety and depression, have rarely been assessed as outcomes in clinical trials, and results are pointing towards the impact of the implantable devices on QoL and mental health not being direct but moderated and mediated by several biomedical as well as psychosocial variables. Furthermore, the cognitive effects of the implantable devices have rarely been assessed in empirical studies, although cognitive impairment is largely associated with the heart disorders that require implantation of an electrical device and cognitive benefits are strongly expected from the therapy. The aim of this book is to collect, appraise and condense the results of all empirical studies that have investigated, even marginally, the relationships between the implantable devices and any psychological, emotional, social and cognitive dimension. This book is a cornerstone for all involved in device utilization (physicians, nurses, technicians, industry representatives) that need to understand this topic.