title: Prognostic implications of Q waves and T-wave inversion associated with early repolarization.
abstract: OBJECTIVE
  To evaluate the prevalence of early polarization (ER) in a stable population and to evaluate the prognostic significance of the association or absence of Q waves or T-wave inversion (TWI).
  
  
  METHODS
  In this retrospective study performed at the university-affiliated Palo Alto Veterans Affairs Health Care Center from March 1, 1987, through December 31, 1999, we evaluated outpatient electrocardiograms. Vital status and cause of death were determined in all patients, with a mean ± SD follow-up of 7.6±3.8 years.
  
  
  RESULTS
  Of the 29,281 patients, 87% were men and 13% were African American. Inferior or lateral ER was present in 664 patients (2.3%): in inferior leads in 185 (0.6%), in lateral leads in 479 (1.6%) , and in both inferior and lateral leads in 163 (0.6%). Only when Q waves or TWI accompanied ER was there an increased risk of cardiovascular death (Cox proportional hazards regression model, 5.0; 95% confidence interval, 3.4-7.2; P<.001).
  
  
  CONCLUSIONS
  Common patterns of ER without concomitant Q waves or TWI are not associated with increased risk of cardiovascular death; however, when either occurs with ER, there is a hazard ratio of 5.0. These findings confirm that ER is a benign entity; however, the presence of Q waves or TWI with ER is predictive of increased cardiovascular death.
authors: Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA.
authors: Abhimanyu
authors: A
authors: Uberoi
authors: Karim
authors: K
authors: Sallam
authors: Marco
authors: M
authors: Perez
authors: Nikhil A
authors: NA
authors: Jain
authors: Euan
authors: E
authors: Ashley
authors: Victor
authors: V
authors: Froelicher
mesh_terms: D000328:Adult; D001741:Black or African American / Q000706:statistics & numerical data; D000368:Aged; D001145:Arrhythmias, Cardiac / Q000208:ethnology / Q000401:mortality* / Q000503:physiopathology*; D002318:Cardiovascular Diseases / Q000401:mortality* / Q000503:physiopathology*; D002423:Cause of Death; D003327:Coronary Disease / Q000401:mortality / Q000503:physiopathology; D004562:Electrocardiography; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology*; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D044465:White People / Q000706:statistics & numerical data