Relation of S-T Depression to Metabolic and Hemodynamic Events

Abstract

An S-T depression of the electrocardiogram [ECG] results from reduction of left main coronary flow in the dog. Intimately associated with this ecg change are metabolic, ionic, and hemodynamic alterations as exhibited by the development of partial anaerobic myocardial metabolism, left ventricular failure, maximal myocardial O2 extraction, minimal coronary vascular resistance, myocardial K efflux, and a widening of the coronary arterio-venous pH difference. All of these alterations are reversible following restoration of coronary flow. Reasons are presented which suggest that the myocardial K loss is related to the S-T depression observed.