ST-segment elevation in the electrocardiogram: a sign of myocardial ischemia.

In 1972 Kjekshus et al. published the seminal article 'Distribution of myocardial injury and its relations to epicardial ST-segment changes after coronary occlusion in the dog' in Cardiovascular Research. In this article it was shown that the ST-segment elevation occurring early after occlusion of the left descending coronary artery was closely related to the depletion of the necrotic cells from creatine kinase and to flow reduction at a later stage (24 h). This correlation was especially prominent if the infarction was transmural. Starting from these phenomenological relationships, this article briefly describes and summarizes the experimental research which was carried out in other laboratories after the publication of Kjekshus et al. Special emphasis is laid on the discussion of the main basic mechanisms which underly the clinically observed ST-segment elevation and its evolution after the acute stage of ischemia, i.e. the changes in the transmembrane action potential and the alteration in electrical cell-to-cell coupling.