Cell behaviour during epithelial to mesenchymal transition (EMT) was simulated using the cellular Potts formalism in Compucell3D. A recent in vitro study revealed that the mechanism of endocardial scattering can be induced independently of invasion into the extracellular matrix (ECM). This suggests that loss of endocardial cohesion alone is not sufficient for full EMT. The 3D simulations, which take account of changes in adhesion, match this conclusion. The principle by which the rate of mitosis regulates the endocardial monolayer was demonstrated; suggesting a route by which VEGF might regulate EMT.