title: Spectrum of ST amplitude: athletes and an ambulatory clinical population.
abstract: OBJECTIVE
  To augment data guiding thresholds for myocardial ischemia and cardiac risk, we studied resting ST amplitude in ambulatory patients and collegiate athletes.
  
  
  METHODS
  We analyzed 4041 ECGs from ambulatory visits at the Veterans Affairs in Palo Alto, California from 1997 to 1999 and 1114 screening ECGs from Stanford University athletes in 2007-2008. Using the PR interval as the isoelectric line and >95μV and<-45μV (visually equivalent to 1mm and 0.5mm) to define ST elevation and depression, ST amplitude was measured at QRS-end.
  
  
  RESULTS
  ST elevation was most prevalent in males, African Americans, and athletes (87% of male athletes in anterior leads). ST depression was rare in athletes and, among patients, associated with time to cardiovascular death in lateral leads (age-adjusted HR of 1.9, p<0.001).
  
  
  CONCLUSIONS
  ST amplitude differs by gender, age, race, and athletic status, which should be considered when developing guidelines for ECG interpretation.
authors.affiliation: The Division of Cardiovascular Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, CA, USA. muramoto@stanford.edu
authors.forename: David
authors.initials: D
authors.lastname: Muramoto
authors.forename: Nikhil
authors.initials: N
authors.lastname: Singh
authors.forename: Sonya
authors.initials: S
authors.lastname: Aggarwal
authors.forename: Myo
authors.initials: M
authors.lastname: Wong
authors.forename: Chandana
authors.initials: C
authors.lastname: Adhikarla
authors.forename: David
authors.initials: D
authors.lastname: Hadley
authors.forename: Victor
authors.initials: V
authors.lastname: Froelicher
mesh_terms: D017677:Age Distribution; D000553:Ambulatory Care / Q000706:statistics & numerical data*; D001145:Arrhythmias, Cardiac / Q000175:diagnosis* / Q000401:mortality*; D002140:California / Q000453:epidemiology; D015897:Comorbidity; D016757:Death, Sudden, Cardiac / Q000453:epidemiology*; D004562:Electrocardiography / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D011379:Prognosis; D016016:Proportional Hazards Models; D018570:Risk Assessment; D017678:Sex Distribution; D013177:Sports / Q000706:statistics & numerical data*; D015996:Survival Rate; D013577:Syndrome
keywords: Ambulatory patients; Collegiate athletes; ST amplitude