TY - JOUR T1 - Relationship of QRS duration at baseline and changes over 60 min after fibrinolysis to 30-day mortality with different locations of ST elevation myocardial infarction: results from the Hirulog and Early Reperfusion or Occlusion-2 trial JF - Heart JO - Heart SP - 276 LP - 282 DO - 10.1136/hrt.2008.146365 VL - 95 IS - 4 AU - C-K Wong AU - W Gao AU - R A H Stewart AU - J K French AU - P E G Aylward AU - H D White Y1 - 2009/02/01 UR - http://heart.bmj.com/content/95/4/276.abstract N2 - Objective: To discern if the prognostic meaning of QRS prolongation differs according to the location of ST elevation acute myocardial infarctionDesign: Measuring QRS duration in patients with normal conduction or right bundle branch blockSetting: HERO-2 trial with prospective collection of electrocardiograms at randomisation and at 60 min after fibrinolytic therapyPatients: 12 456 patients with normal conduction at both randomisation and 60-min time points and 510 with right bundle branch block (RBBB) at both time pointsMain outcome measure: 30-day mortality.Results: On the baseline ECG, there was a positive association between QRS duration and 30-day mortality with anterior acute myocardial infarction (AMI) (p<0.0001 for those with normal conduction and  = 0.007 for those with RBBB) but not with inferior AMI (p = 0.29 and p = 0.32, respectively). For anterior AMI, with or without RBBB, an increment of 20 ms increase in QRS duration predicted a significant 30–40% relative increase in 30-day mortality both before and after adjusting for clinical and ECG variables including baseline ST elevation and presence of Q waves. The association was not present for inferior AMI. Changes in QRS duration over 60 min after fibrinolytic therapy were uncommon and unrelated to mortality.Conclusion: Baseline QRS duration independently stratifies 30-day mortality in patients with anterior AMI, even when unaccompanied by RBBB, but does not stratify mortality risk in patients with inferior AMI. ER -