The ultrastructure of differentiating cells of the heart muscle in the state of mitotic division.
D000818:Animals; D002454:Cell Differentiation; D006321:Heart / Q000196:embryology; D006352:Heart Ventricles; D008722:Methods; D008854:Microscopy, Electron; D008938:Mitosis; D009206:Myocardium / Q000166:cytology*; D009210:Myofibrils; D051381:Rats