The stem cells are located in the outermost layer of the heart and could one day play a critical role in regenerating injured heart tissue, the researchers say.
"In heart failure, you lose cardiomyocytes, so the only way to reverse heart failure is to make more of these cells," said William Pu, the study's lead researcher and a pediatric cardiologist at Children's Hospital in Boston, Massachusetts.
The new findings come on the heels of two earlier breakthroughs. In 2006 scientists identified another cardiac stem cell
