title: Diagnostic performance and potential clinical impact of advanced care paramedic interpretation of ST-segment elevation myocardial infarction in the field.
abstract: OBJECTIVE
  Most studies of pre-hospital management of ST-elevation myocardial infarction (STEMI) have involved physicians accompanying the ambulance crew, or electrocardiogram (ECG) transmission to a physician at the base hospital. We sought to determine if Advanced Care Paramedics (ACPs) could accurately identify STEMI on the pre-hospital ECG and contribute to strategies that shorten time to reperfusion.
  
  
  METHODS
  A STEMI tool was developed to: 1) measure the accuracy of the ACPs at diagnosing STEMI; and 2) determine the potential time saved if ACPs were to independently administer thrombolytic therapy. Using registry data, we subsequently estimated the time saved by initiating thrombolytic therapy in the field compared with in-hospital administration by a physician.
  
  
  RESULTS
  Between August 2003 and July 2004, a correct diagnosis of STEMI on the pre-hospital ECG was confirmed in 63 patients. The performance of the ACPs in identifying STEMI on the ECG resulted in a sensitivity of 95% (95% confidence interval [CI] 86%-99%), a specificity of 96% (95% CI 94%-98%), a positive predictive value (PPV) of 82% (95% CI 71%-90%), and a negative predictive value (NPV) of 99% (95% CI 97%-100%). ACP performance for appropriately using thrombolytic therapy resulted in a sensitivity of 92% (95% CI 78%-98%), a specificity of 97% (95% CI 94%-98%), a PPV of 73% (95% CI 59%-85%) and an NPV of 99% (95% CI 97%-100%). We estimated that the median time saved by ACP administration of thrombolytic therapy would have been 44 minutes.
  
  
  CONCLUSIONS
  ACPs can be trained to accurately interpret the pre-hospital ECG for the diagnosis of STEMI. These results are important for the design of regional integrated programs aimed at reducing delays to reperfusion.
authors.affiliation: University of Ottawa Heart Institute, Ottawa, ON.
authors.forename: Michel R
authors.initials: MR
authors.lastname: Le May
authors.forename: Richard
authors.initials: R
authors.lastname: Dionne
authors.forename: Justin
authors.initials: J
authors.lastname: Maloney
authors.forename: John
authors.initials: J
authors.lastname: Trickett
authors.forename: Irene
authors.initials: I
authors.lastname: Watpool
authors.forename: Michel
authors.initials: M
authors.lastname: Ruest
authors.forename: Ian
authors.initials: I
authors.lastname: Stiell
authors.forename: Sheila
authors.initials: S
authors.lastname: Ryan
authors.forename: Richard F
authors.initials: RF
authors.lastname: Davies
mesh_terms: D000552:Ambulances; D002170:Canada; D004562:Electrocardiography / Q000706:statistics & numerical data; D004634:Emergency Medical Technicians / Q000193:education; D005260:Female; D006801:Humans; D008297:Male; D017202:Myocardial Ischemia / Q000188:drug therapy / Q000473:pathology*; D011237:Predictive Value of Tests; D011795:Surveys and Questionnaires; D015912:Thrombolytic Therapy; D013997:Time Factors; D000078329:Workforce