Background: Different electrocardiographic changes have been described during thrombolytic therapy for acute myocardial infarction to indicate successful reperfusion. The occluded coronary artery also can be reopened by percutaneous transluminal coronary angioplasty (PTCA). This study was performed to compare electrocardiographic changes during primary or rescue PTCA and thrombolytic therapy. The electrocardiographic changes were studied directly at the moment of reperfusion during PTCA.
Methods and results: Continuous 12-lead electrocardiographic monitoring was performed in 110 patients with acute myocardial infarction undergoing a reperfusion intervention (thrombolytic therapy or primary or rescue PTCA) to assess electrocardiographic changes during reperfusion. Patency and Thrombolysis In Myocardial Infarction flow in the infarct-related artery were assessed by coronary angiography. During reperfusion of the infarct-related coronary artery, early signs of reperfusion were an increase of ST-segment deviation (30%), ST-segment normalization (70%), and terminal T-wave inversion (60%); only 11% of patients showed no ST-segment changes. Thrombolytic therapy was significantly more often accompanied by a transient increase in ST-segment deviation compared with primary PTCA. Accelerated idioventricular rhythm was documented in 51%, an increase in the number of ventricular premature complexes in 42%, nonsustained ventricular tachycardia in 7%, and bradycardia in 18% of all patients.
Conclusions: This study confirms the occurrence of specific electrocardiographic changes at the time of reperfusion. The pattern of ST-segment change upon reperfusion relates to the type of treatment. Awareness of electrocardiographic changes at the moment of reperfusion will help to select patients for rescue PTCA and can be used to assess the effect of future pharmacologic interventions to limit reperfusion damage.