The phrase "embryonic heart" refers to the early stage of development of a heart in a growing organism, such as a baby. It is the initial form of the heart before it fully develops into a functioning organ. Full definition
A molecular switch that seems to be essential for embryonic heart cells to grow into more mature, adult - like heart cells has been discovered. (sciencedaily.com)
Another gene active in the peduncle is related to one that, in higher organisms, functions prominently in embryonic heart tissue. (discovermagazine.com)
In laboratory experiments with mice that had experienced a heart attack, Drs. Qian and Srivastava delivered three genes that normally guide embryonic heart development — together known as GMT — directly into the damaged region. (gladstone.org)