title: Prognostic significance of electrocardiographic Q-waves in a low-risk population.
abstract: OBJECTIVE
  In individuals without known heart disease, electrocardiographic Q-waves predict a poor prognosis. We aimed to examine whether prognostic information can be derived from the size and location of Q-waves in persons from the general population without known ischaemic heart disease (IHD) or heart failure (HF).
  
  
  RESULTS
  Electrocardiograms (ECGs) of 5381 persons without known IHD or HF from the 4th Copenhagen City Heart Study were reviewed and Q-waves were classified according to their size and location. Multivariate Cox proportional hazards regression models were used to examine the associations of Q-waves adjusted for age, hypertension, diabetes, and estimated glomerular filtration rate with the risk of the combined endpoint of death and hospitalization for IHD. During a median of 7.8 years of follow-up, 1003 persons reached the combined endpoint. One hundred and fourteen (2.1%) had pathological Q-waves, of whom 44% suffered from an event compared with 18% from the control group, P< 0.001. Persons with hypertension, diabetes, and impaired renal function were more likely to have Q-waves. Even small Q-waves (i.e. Minnesota code 1.2.x-1.3.x) were associated with a poor prognosis, hazard ratio (HR) 1.4 [95% confidence interval (CI): 1.0-2.0; P< 0.05], though not as grave as large Q-waves (i.e. Minnesota code 1.1.x) HR 2.8 (95%CI: 1.6-5.0; P< 0.001). Conversely, there was no difference in the outcome of patients with anteriorly HR 1.6 (95%CI: 1.1-2.4) vs. posteriorly HR 1.5 (95%CI: 0.9-2.4) located Q-waves (P= 0.85).
  
  
  CONCLUSIONS
  In the general population without known IHD or HF, even small Q-waves in the ECG are associated with a poor prognosis.
authors.affiliation: The Copenhagen City Heart Study, Bispebjerg Hospital, Copenhagen, Denmark. petergodsk@gmail.com
authors.forename: Peter
authors.initials: P
authors.lastname: Godsk
authors.forename: Jan Skov
authors.initials: JS
authors.lastname: Jensen
authors.forename: Steen Z
authors.initials: SZ
authors.lastname: Abildstrøm
authors.forename: Merete
authors.initials: M
authors.lastname: Appleyard
authors.forename: Sune
authors.initials: S
authors.lastname: Pedersen
authors.forename: Rasmus
authors.initials: R
authors.lastname: Mogelvang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003718:Denmark; D004562:Electrocardiography / Q000379:methods* / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000401:mortality*; D011379:Prognosis; D015203:Reproducibility of Results; D012307:Risk Factors; D012680:Sensitivity and Specificity; D016019:Survival Analysis; D015996:Survival Rate; D055815:Young Adult