Sudden increase of the ST segment elevation at time of reperfusion predicts extensive infarcts in patients with intravenous thrombolysis

Within 4 hours from the onset of symptoms in 61 patients with myocardial infarction and intravenous thrombolysis, ST segment elevation and creatine phosphokinase (CK) were measured every 15 minutes. Because of a premature enzyme rise, 42 patients (69%) were reperfused early (group 1). Immediately following reperfusion, eight of them (13%, group 1a) showed a marked increase of the ST elevation, in six of whom it was associated with clearly intensified chest pain. These patients exhibited a much steeper enzyme release and developed a larger enzymatic infarct size than patients (group 1b) without an additional transient ST elevation at reperfusion (CK peak 5.1 ± 1.6 vs 9.8 ± 4.2 hours after the start of thrombolysis; CK release 48 ± 22 vs 19 ± 18 IU/ml × hours, both p < 0.005). At angiography 11 days later, left ventricular function was significantly worse in group 1a than in group 1b (regional dyssynergic area 51 ± 24 vs 21 ± 18, global ejection fraction 39 ± 14 vs 58 ± 11; both p < 0.0005). During intravenous thrombolysis in acute myocardial infarction, some patients show a marked transient increase of the ST segment elevation at reperfusion. Their enzyme rise is very rapid and suggests a special reperfusion pattern. Most of these patients suffered large infarcts.