Careful assessment of the ECG and the release patterns of biochemical markers after established reperfusion has made it possible to relate the observed changes to the degree of myocardial salvage, left ventricular function, and clinical outcomes. These observations will become increasingly important in assisting the clinician to stratify patients into different prognostic categories during acute MI treated with thrombolytic therapy. In the future, risk stratification based on noninvasive indices provided by ECG and biochemical markers will aid physicians in optimally using thrombolytic therapy.