title: Pathological Q waves in myocardial infarction in patients treated by primary PCI.
abstract: OBJECTIVE
  In the present study, we investigated the association of pathological Q waves with infarct size. Furthermore, we investigated whether Q-wave regression was associated with improvement of left ventricular ejection fraction (LVEF), infarct size, and left ventricular dimensions in ST-segment elevation myocardial infarction (STEMI) patients with early Q-wave formation compared with patients without or persistent pathological Q waves.
  
  
  BACKGROUND
  The criteria for pathological Q waves after acute myocardial infarction (MI) have changed over the years. Also, there are limited data regarding correlation of Q-wave regression and preservation of LVEF in patients with an initial Q-wave MI.
  
  
  METHODS
  Standard 12-lead electrocardiograms (ECGs) were recorded in 184 STEMI patients treated with primary percutaneous coronary intervention (PCI). ECGs were recorded before and following PCI, as well as at 1, 4, 12, and 24 months of follow-up. An ECG was scored as Q-wave MI when it showed Q waves in 2 or more contiguous leads according to the 4 readily available clinical definitions used over the years: "classic" criteria, Thrombolysis In Myocardial Infarction criteria, and 2000 and 2007 consensus criteria. Cardiac magnetic resonance (CMR) examination was performed at 4 ± 2 days after reperfusion and repeated after 4 and 24 months. Contrast-enhanced CMR was performed at baseline and 4 months.
  
  
  RESULTS
  The classic ECG criteria showed strongest correlation with infarct size as measured by CMR. The incidence of Q-wave MI according to the classic criteria was 23% 1 h after PCI. At 24 months of follow-up, 40% of patients with initial Q-wave MI displayed Q-wave regression. Patients with a Q-wave MI had larger infarct size and lower LVEF on baseline CMR (24 ± 10% LV mass and 37 ± 8%, respectively) compared with patients with non-Q-wave MI (17 ± 9% LV mass, p < 0.01, and 45 ± 8%, p < 0.001, respectively). Patients with Q-wave regression displayed significantly larger LVEF improvement in 24 months (9 ± 11%) as compared with both persistent Q-wave MI (2 ± 8%) as well as non-Q-wave MI (3 ± 8%, p = 0.04 for both comparisons).
  
  
  CONCLUSIONS
  Association of Q waves with infarct size is strongest when using the classic Q-wave criteria. Q-wave regression is associated with the largest improvement of LVEF as assessed with CMR.
authors: Department of Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors: Ronak
authors: R
authors: Delewi
authors: Georges
authors: G
authors: Ijff
authors: Tim P
authors: TP
authors: van de Hoef
authors: Alexander
authors: A
authors: Hirsch
authors: Lourens F
authors: LF
authors: Robbers
authors: Robin
authors: R
authors: Nijveldt
authors: Anja M
authors: AM
authors: van der Laan
authors: Pieter A
authors: PA
authors: van der Vleuten
authors: Cees
authors: C
authors: Lucas
authors: Jan G P
authors: JG
authors: Tijssen
authors: Albert C
authors: AC
authors: van Rossum
authors: Felix
authors: F
authors: Zijlstra
authors: Jan J
authors: JJ
authors: Piek
mesh_terms: D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D009203:Myocardial Infarction / Q000628:therapy*; D009206:Myocardium / Q000473:pathology*; D062645:Percutaneous Coronary Intervention