The complete Selvester QRS scoring system is a validated quantitative method of estimating the size of single myocardial infarcts. It remains to be validated in patients with multiple infarcts and in those with confounding factors such as ventricular hypertrophy or fascicular or bundle branch blocks. Discrepancies in its correlation with other sizing methods might give insight into the amount of infarct reperfusion (versus enzymatic methods) or the amount of residual ischemic myocardium (versus mechanical methods). Several strategies have now been presented for quantitative use of the initial ST segment deviation to indicate important clinical parameters such as the precise location of the coronary occlusion, the amount of myocardium in jeopardy, and the potential for salvage by reperfusion. Comparison of the initial ST deviation with final QRS score and with non-ECG methods of estimating the per cent of LV that is scarred and/or dysfunctional might indicate the effect of therapeutic reperfusion on MI healing. These methods remain to be validated and, as yet, no comprehensive ST segment scoring system has been developed. Use of both QRS and ST methods will be facilitated by the development of new ECG recording systems and by automated application of the various criteria. It is likely that acute coronary care in 1990 will include sophisticated methods for continuous monitoring of QRS and ST and T changes. There will be continuous trending of scores indicating the amount of ischemic and infarcted myocardium. Base-line measurements can be obtained before interventions have begun in order to indicate the potential benefit of altering the natural course for the individual patient.(ABSTRACT TRUNCATED AT 250 WORDS)