The study was continued through May, 2010 to to investigate the natural history of cardiomyopathy and transplantation, establish a longitudinal cohort for investigating the functional status of children with cardiomyopathy, and conduct viral and genetic testing to assess associations of genetic and viral markers of cardiomyopathy with clinical and functional outcomes. There are three specific aims. The first expands on the natural history of cardiomyopathy and transplantation by integrating the Pediatric Cardiomyopathy Registry (PCMR) and the Pediatric Heart Transplant Study databases in order to examine whether and how cardiac transplantation modifies the clinical course of cardiomyopathy in children. The second specific aim focuses on the functional status of pediatric cardiomyopathy patients. The study will establish the longitudinal course of functional status in children with cardiomyopathy, and analyze the relationship to clinical events and outcomes. This will be accomplished by assessment of the functional status of pediatric cardiomyopathy patients, including the subset of children undergoing heart transplantation, by continuation of the current PCMR Functional Status Substudy and extension of the study to children in the post-transplant-period period. The third specific aim relates to viral and genetic testing and will investigate how genetic and viral markers of cardiomyopathy are associated with clinical and functional outcomes. Cardiac tissue and blood samples will be collected from 300 children with cardiomyopathy for viral genome and genetic screening 9G4.5 gene) using the Pediatric Cardiomyopathy Repository, and the results will be correlated to clinical outcome.