OBJECTIVE: To discern if the prognostic meaning of QRS prolongation differs according to the location of ST elevation acute myocardial infarction DESIGN: Measuring QRS duration in patients with normal conduction or right bundle branch block SETTING: HERO-2 trial with prospective collection of electrocardiograms at randomisation and at 60 min after fibrinolytic therapy PATIENTS: 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 points MAIN 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.
RCT Entities:
OBJECTIVE: To discern if the prognostic meaning of QRS prolongation differs according to the location of ST elevation acute myocardial infarction DESIGN: Measuring QRS duration in patients with normal conduction or right bundle branch block SETTING: HERO-2 trial with prospective collection of electrocardiograms at randomisation and at 60 min after fibrinolytic therapy PATIENTS: 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 points MAIN 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.
Authors: Susan Cheng; Martin G Larson; Michelle J Keyes; Elizabeth L McCabe; Christopher Newton-Cheh; Daniel Levy; Emelia J Benjamin; Ramachandran S Vasan; Thomas J Wang Journal: Am J Cardiol Date: 2010-07-23 Impact factor: 2.778
Authors: Cheuk-Kit Wong; Wanzhen Gao; Ralph A H Stewart; Jocelyne Benatar; John K French; Philip E G Aylward; Harvey D White Journal: Eur Heart J Date: 2010-05-31 Impact factor: 29.983
Authors: Harvey D White; Cheuk-Kit Wong; Wanzhen Gao; Aaron Lin; Jocelyne Benatar; Philip Eg Aylward; John K French; Ralph A Stewart Journal: Eur Heart J Acute Cardiovasc Care Date: 2012-09