title: Use of prehospital 12-lead electrocardiography and treatment times among ST-elevation myocardial infarction patients with atypical symptoms.
abstract: OBJECTIVE
  Guidelines advise that a prehospital electrocardiogram (ECG) should be obtained in any patients with chest pain, yet up to 20% of patients with ST-elevation myocardial infarction (STEMI) do not present with chest pain. The objective was to determine the association of atypical presentations in the prehospital setting on the likelihood of receiving a prehospital ECG and subsequent time to reperfusion therapy.
  
  
  METHODS
  This study used a data set that linked prehospital medical information from a statewide EMS data system with a clinical registry of treatment and outcomes data for patients with STEMI. Among 2,639 STEMI patients from 2008 to 2010, the association between non-chest pain presentations, prehospital ECG use, and reperfusion times among patients undergoing primary percutaneous coronary intervention (PCI) were examined. Inverse probability weights were used to account for observed baseline confounders.
  
  
  RESULTS
  Overall, 318 of 2,639 patients (12.1%) presented without chest pain. A prehospital ECG was obtained in 2,021 of 2,321 (87.1%) patients with chest pain compared with only 230 of 318 (72.3%) without chest pain (odds ratio [OR] = 2.24, 95% confidence interval [CI] = 1.69 to 2.98). Among patients without chest pain, those who received a prehospital ECG had significantly shorter first medical contact (FMC) to device times (30.9% < 90 minutes vs. 11.4% > 90 minutes, adjusted OR = 2.81, 95% CI = 1.29 to 6.11, p < 0.01).
  
  
  CONCLUSIONS
  Over one-quarter of STEMI patients presenting without chest pain did not receive prehospital ECGs and had significantly longer FMC to device times. Future efforts are needed to promote the use of prehospital ECGs to achieve more rapid identification of STEMI patients with atypical presentations in the prehospital setting.
authors.affiliation: Department of Emergency Medicine, University of North Carolina (UNC) School of Medicine, Chapel Hill, NC.
authors.forename: Austin R
authors.initials: AR
authors.lastname: Cannon
authors.forename: Li
authors.initials: L
authors.lastname: Lin
authors.forename: Barbara
authors.initials: B
authors.lastname: Lytle
authors.forename: Eric D
authors.initials: ED
authors.lastname: Peterson
authors.forename: Charles B
authors.initials: CB
authors.lastname: Cairns
authors.forename: Seth W
authors.initials: SW
authors.lastname: Glickman
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002637:Chest Pain / Q000209:etiology*; D015331:Cohort Studies; D003625:Data Collection; D004562:Electrocardiography / Q000706:statistics & numerical data*; D004632:Emergency Medical Services / Q000379:methods*; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications / Q000175:diagnosis* / Q000628:therapy; D009657:North Carolina; D062645:Percutaneous Coronary Intervention / Q000706:statistics & numerical data*; D017064:Process Assessment, Health Care; D012042:Registries; D012189:Retrospective Studies; D013997:Time Factors