IS SUDDEN REPERFUSION MORE ARRHYTHMOGENIC DURING INTRAVENOUS THROMBOLYSIS FOR ACUTE MYOCARDIAL-INFARCTION

The object of this study was to analyse ventricular arrhythmias occurr ing during intravenous thrombolysis for acute myocardial infarction wi th respect to ST segment changes on 24 hour Holter ECG monitoring init iated at the same time as thrombolytic therapy and on repeated 12 lead electrocardiogrammes. Forty-one patients in whom the infarct-related artery was patent at coronary angiography carried out 30.5 +/- 3.1 hou rs (less than or equal to 24 hours in 59 % of cases) after the onset o f chest pain were included. The time to normalisation of the ST segmen t was defined as the interval between maximum ST elevation to a steady state and helped identify rapid(less than or equal to 60 minutes, n = 13) from intermediate (60-180 minutes, n = 15) and slow > 180 minutes , n = 13) reperfusion. The incidence of ventricular arrhythmias was th e same in all three groups, except for prolonged ventricular tachycard ias (> 15 complexes): 69 %, 13 % and 15 % respectively (p = 0.002). Th e number of arrhythmias was greater when the ST segment changes were r apid than when they were intermediate or slow. This was true for ventr icular extrasystoles (p < 0.05), accelerated idioventricular rhythms ( p < 0.05), early (less than or equal to 6 hours from onset of thrombol ysis) accelerated idioventricular rhythms (p < 0.01) and ventricular t achycardias (p < 0.05). Therefore, the number of ventricular arrhythmi as seems to be related to the speed of ST segment change, suggesting t hat more sudden reperfusion is more arrhythmogenic.