Despite the major advances made over the last decade, mortality following acute MI is still high for patients even if treated with the so far most effective "front-loaded" rt-PA regimen: 30-day-mortality is 6.3% and is associated with fatal cerebral haemorrhage in 1.5%. Further improvement of short- and long-term prognosis can be achieved if infusion of the thrombolytic agent starts early, if reperfusion occurs more rapidly and if a persistent TIMI grade 3 flow of the infarct-related artery can be achieved. These are prerequisites for optimal preservation of ventricular function and predictors of a favourable outcome.