A new electrocardiographic marker of myocardial reperfusion in patients with acute ST-segment elevation myocardial infarction treated with primary percutaneous intervention: the value of QRS duration.

Aims: Although ischaemia-induced QRS complex changes have been described previously, their relation with reperfusion status is not clear. We aimed to investigate the relation of QRS duration with reperfusion at tissue level compared to myocardial blush in patients with acute myocardial infarction who underwent successful primary percutaneous coronary angioplasty.

Methods And Results: One hundred and forty-eight patients were enrolled. Based on the post-angioplasty myocardial blush grade (MBG), patients were divided into reperfusion (grades 2 and 3) and impaired reperfusion (grades 0 and 1) groups. Although the two groups did not differ in terms of admission QRS duration (81±17 vs. 79±15 msec, p=0.473), the patients in the impaired reperfusion group had a significantly longer QRS duration both at immediate post-angioplasty (78±18 vs. 68±17 msec, p=0.001) and at the 60th minute ECG (77±17 vs. 60±17 msec, p<0.001). Patients in the impaired reperfusion group revealed significantly less narrowing of QRS duration in the post-angioplasty 60th minute ECG (6±5 vs. 20±5 msec, p<0.001) when compared to the patients in the reperfusion group. After adjusting all variables, QRS narrowing in the 60th minute ECG was determined as an independent electrocardiographic predictor of reperfusion (OR:1.39, 95% CI: 1.25-1.54, p<0.001).

Conclusions: We demonstrated that QRS duration is a strong indicator of myocardial reperfusion status.