Prognostic significance of an ST segment depression of patients with an acute coronary attack

An ST-segment depression was studied in the ECGs recorded on the first and third day after admission of 580 patients with an acute heart attack. An acute myocardial infarction was found in 86% of the 115 patients in whose ECG the J-point was depressed 2 mm. or more and the ST-segment was horizontal or sloping downwards in at least one lead (a definite ST-segment depression). The degree of the J-point depression was deemed of prognostic significance. During the first four weeks, the mortality rate was lowest (4.7%) in patients with a J-point depression less than one millimeter or no depression. The corresponding figure for patients with a definite ST-segment depression was three times (21.7%) that of the patients without the pattern (7.3%). The definite ST-segment depression in an acute coronary attack seemed to be accompanied by a severe degree of coronary heart disease. Significant differences between the patients with a definite ST-segment depression and those without the pattern were found in the C T ratio, in the degree of pulmonary congestion, in the ECG signs of LVH, and in the digitalis treatment. It is concluded that the definite ST-segment depression has an important clinical and prognostic significance in cases of acute coronary attacks.