This invention provides a method of treating a disorder of a subject's heart involving loss of cardiomyocytes which comprises administering to the subject an amount of an agent effective to cause cardiomyocyte proliferation within the subject's heart so as to thereby treat the disorder. This invention further provides the instant method wherein the agent is human endothelial progenitor cells, G-CSF, GM-CSF, SDF-1, and IL-8. This invention also provides methods of determining the susceptibility of a cardiomyocyte in a subject to apoptosis.
