In vertebrate embryonic development, the heart is the first organ that becomes functional. Embryonic heart development involves cardiomyocyte specification, differentiation, or heart morphogenesis. The intricate process of embryonic development requires precise tem- poral and spatial regulation of gene expression and protein activity (Epstein, 2010; Liu and Olson, 2010). Errors in these processes can result in chamber hypoplasia and incorrect alignment of the atria and great ar- teries with the ventricles, which produces the worst forms of congenital