Biopsy samples are taken at the time of right heart catheterization. They are frozen in a GMP facility at the University of Louisville. The tissue is shipped either to the Institue of Molecular Caridology, Louisville, KY or shipped overnight to the Brigham and Women's Hospital in Boston, MA. The tissue is enzymatically dissociated, and cardiac stem cells are isolated and maintained in culture for 6-8 passages (point of clinical utility). During that time period, experimentation is carried out to charcterize the biological attributes of these cell populations. After this experimentation is complete, the cultures are destroyed in accordance with the biohazard handling policies of the individual institution.