Transmission electron microscopic images of the EMTs. A: Representative cardiomyocyte-like cell (small arrow). B: Uniformly distributed myofilaments (small arrow). C: Z line-like substances, a distinct electron dense material (small arrow). D and E: Presence of the specialized cell- cell junctions, including the intercalated disc containing desmosomes (small arrow) and gap junctions (small arrow), characteristic of connections of heart tissue. F: Typical capillary (open arrow) composed of endothelial cells (small arrow) and a pericyte (broad arrow) is observed within the construct.