QRS Complex Duration is a Marker of Reperfusion in Patients Presenting with Acute ST Segment Elevation Myocardial Infarction

Abstract

Background: Acute myocardial ischemia decreases electrical conduction velocity through the ischemic myocardium, the aim of the study is to evaluate the value of the change in QRS complex duration as a marker of reperfusion in patients presenting with ST segment elevation myocardial infarction. Methods: The study included 100 patients presented with ST segment elevation myocardial infarction, 50% treated with fibrinolysis and 50% with primary Percutaneous intervention, all patients were subjected to 12 lead electrocardiography with measurement of QRS complex duration (in millisecond) on admission, sixty and ninety minutes post reperfusion , coronary angiography was done to all patients and they were divided into two groups according to myocardial blush grade, group A (5 5%) with normal reperfusion (grade 2 and 3) and group B (45%) with impaired reperfusion (grade 0 and 1). Results: We found that the admission QRS duration didn’t differ in the two groups (p=0.859), and QRS complex duration was found to be significantly shorter in group A at both 60 and 90 min post reperfusion (pE‚0.001 for both), and found a strong positive correlation between myocardial blush grade and QRS complex narrowing at both 60 min and 90 min post reperfusion respectively (r=0.731, pE‚0.001 and r=0.739, pE‚0.001). A cut off 10 msec was determined to be the best QRS complex narrowing duration for prediction of reperfusion at both 60 and 90 min post reperfusion with 100% sensitivity, and a specificity of (43.64% and 58.18%) at 60 min and 90 min post reperfusion respectively. Conclusion: QRS duration changes post reperfusion is strongly correlated to myocardial reperfusion in patients presenting with ST segment elevation myocardial infarction.