Summary: Using scanning electron microscopy, the endothelium of normal left ventricle was compared with that overlying experimentally-induced myocardial infarcts in dogs. Ten minutes after coronary artery ligation there was no apparent difference, but at intervals from 20 to 360 minutes, patches of altered endothelium were evident over the ischaemic muscle. In affected areas there was separation of endothelial cells along intercellular boundaries and the loss of many, but not all, endothelial cells. Up to two hours after coronary ligation the depressions left by the missing cells were smoothly rounded with prominent intercellular lines separating them. However, after six hours, the bases of these depressions were rough and the intercellular lines indistinct due to the loss of a layer of supporting material originally lying between the endothelial cells and underlying connective tissue fibres.
(C) 1973 Royal College of Pathologists of Australasia