Disclosed is a pharmaceutical composition comprising a population of isolated human adult c-kit positive cardiac stem cells and a pharmaceutically acceptable carrier, wherein at least 50% of said isolated cardiac stem cells have immortal DNA. Also disclosed is a substantially pure population of adult cardiac stem cells which are c-kit positive, IGF-1 receptor positive, p16INK4a negative, and have immortal DNA. Further disclosed is a method for isolating adult cardiac stem cells having immortal DNA comprising: (a) exposing adult cardiac stem cells to a DNA label, wherein said cardiac stem cells are c-kit positive and isolated from myocardial tissue (b) culturing said labelled cardiac stem cells for at least one population doubling and (c) selecting the cardiac stem cells that are negative for the DNA label, wherein said selected stem cells are cardiac stem cells having immortal DNA.
