1. The aim of this study was to evaluate the utility of measurement of left ventricular function in assessing the efficacy of thrombolytic agents. 2. All published studies were reviewed. 3. The major effect of the introduction of thrombolytic therapy on mortality after myocardial infarction has been a dramatic decrease in the number of patients dying from cardiac failure. In the thrombolytic era, left ventricular function has remained the most important prognostic factor after recovery from acute myocardial infarction. There are three trials with the statistical power to evaluate left ventricular function, where both left ventricular function and survival were improved compared to placebo or control treatment. The recent Global Utility of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries (GUSTO) Trial supports these findings, with left ventricular function being strongly correlated with mortality reduction. Left ventricular function, measured at 90 min either as ejection fraction, end-systolic volume or infarct zone contractility, closely correlated with 30 day mortality, P < 0.01. 4. Left ventricular function remains an important factor in the evaluation of the efficacy of different thrombolytic and adjuvant regimens.