title: Initial electrocardiogram as determinant of hospital course in ST elevation myocardial infarction.
abstract: BACKGROUND
  A proportion of patients with ST elevation myocardial infarction (STEMI) have an initial electrocardiogram (ECG) that is nondiagnostic and are definitively diagnosed on a subsequent ECG. Our aim was to assess whether patients with a nondiagnostic initial ECG are different than those with a diagnostic initial ECG.
  
  
  METHODS
  We collected demographic, ECG, medication, angiographic, and in-hospital clinical outcome data in consecutive patients undergoing primary percutaneous coronary intervention for STEMI at our institution from June 2009 to June 2013.
  
  
  RESULTS
  A total of 334 patients were included, 285 (85%) diagnosed on the initial ECG and 49 (15%) on a subsequent ECG. Patients with a nondiagnostic initial ECG had more comorbidities including prior congestive heart failure (14% vs. 3%, p < .001), coronary artery disease (47% vs. 24%, p = .001), diabetes (37% vs. 16%, p = .001), and hyperlipidemia (55% vs. 40%, p = .048); higher rates of chronic medication use including aspirin (47% vs. 27%, p = .005), beta-blocker (47% vs. 22%, p < .001), and statins (53% vs. 28%, p = .001); longer door-to-balloon times (106 min vs. 45 min, p < .001); lower peak troponin levels (25 ng/ml vs. 50 ng/ml, p = .004), longer diagnostic ECG to balloon times (84 min vs. 75 min, p = .006); and higher rates of a patent infarct-related artery on baseline angiography (41% vs. 24%, p = .018) which remained significant in a multivariable logistic regression model.
  
  
  CONCLUSIONS
  Approximately one in seven STEMI patients had an initial ECG that was nondiagnostic for STEMI. These patients had more comorbidities, higher rates of medication use, and received delayed intervention (even after the diagnosis was definitive).
authors.affiliation: Department of Medicine, Division of Cardiology, University of Virginia, Charlottesville, VA, USA.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Millard
authors.affiliation: Department of Medicine, Division of Cardiology, University of Virginia, Charlottesville, VA, USA.
authors.forename: Vijaiganesh
authors.initials: V
authors.lastname: Nagarajan
authors.affiliation: Department of Medicine, Division of Cardiology, University of Virginia, Charlottesville, VA, USA.
authors.forename: Luke C
authors.initials: LC
authors.lastname: Kohan
authors.affiliation: Houston Methodist DeBakey Heart & Vascular Center, Houston, TX, USA.
authors.forename: Robert C
authors.initials: RC
authors.lastname: Schutt
authors.affiliation: Department of Medicine, Division of Cardiology, University of Virginia, Charlottesville, VA, USA.
authors.forename: Ellen C
authors.initials: EC
authors.lastname: Keeley
mesh_terms: D000368:Aged; D004562:Electrocardiography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D000072657:ST Elevation Myocardial Infarction / Q000175:diagnosis* / Q000503:physiopathology*
keywords: 
  STEMI
  ; initial ECG