M-complex: the electrocardiographic sign of impending cardiac rupture following myocardial infarction.

Abstract

Out of 284 patients admitted to the Coronary-Care Unit, 60 patients showed an acute monophasic injury pattern (M-Complex) on their initial electrocardiogram (ECG). There were 13 fatalities on the first day of myocardial infarction; 6 from the M-complex group. Three of these 6 patients died with cardiac rupture. The ECG features of these 3 patients were compared with the 3 non-rupture patients. A progressive increase in the elevated R-ST segment of the M-complex with an upward ‘pull’ of the R-ST junction, proved to be an ominous ECG sign of impending cardiac rupture in patients with protracted chest pain and persistent hypertenison. The 3 non-rupture patients remained in a hypotensive state from admission to the time of death. Atrioventricular block and A-V junctional tachycardia were the commonest rhythm disturbances in patients dying with cardiac rupture.