title: Simultaneous comparison of 3 derived 12-lead electrocardiograms with standard electrocardiogram at rest and during percutaneous coronary occlusion.
abstract: OBJECTIVE
  The aim of the study was to simultaneously test the EASI lead system and two other derived ECG methods against the standard 12-lead ECG during percutaneous coronary intervention (PCI).
  
  
  METHODS
  During 44 percutaneous coronary interventions, a simultaneously recorded 12-lead and EASI ECG were marked at the start of the PCI (baseline) and at known ischemia caused by balloon inflation (peak). ST deviations were measured 60 ms after the J point at baseline and peak in all leads and were summated (SUMST) to assess overall changes. For regional changes, the lead with the highest ST deviation (PEAKST) was marked. For each patient, derived 12-lead ECGs were computed from the EASI leads and a lead subset using patient-specific coefficients (PS) and coefficients based on a patient population (GEN). Absolute differences were computed between each derived and routine ECG for SUMST and PEAKST.
  
  
  RESULTS
  SUMST was at baseline 567 microV (range: 150-1707) and increased at peak to 871 microV (range: 350-2101). SUMST difference at peak was for EASI: 163 microV (CI: 90-236, P <.001), GEN: 46 microV (CI: 2-91, P = .40), and PS: 16 microV (CI: 3-30, P = .15). PEAKST difference at peak was for EASI: 49 microV (CI: 19-220, P = .02), GEN: 48 microV (CI: -43-154, P = .26), and PS: 20 microV (CI: -51-32, P = .65).
  
  
  CONCLUSIONS
  Simultaneous direct comparison of three derived ECG methods shows overall and regional differences in accuracy across PS, GEN, and EASI. Median SUMST and PEAKST differences for PS are lower than for GEN and EASI, and show a more accurate reconstruction.
authors.affiliation: Thoraxcentrum, Erasmus MC, Rotterdam, The Netherlands. s.nelwan@erasmusmc.nl
authors.forename: Stefan P
authors.initials: SP
authors.lastname: Nelwan
authors.forename: Jan A
authors.initials: JA
authors.lastname: Kors
authors.forename: Suzanne W
authors.initials: SW
authors.lastname: Crater
authors.forename: Simon H
authors.initials: SH
authors.lastname: Meij
authors.forename: Teus B
authors.initials: TB
authors.lastname: van Dam
authors.forename: Maarten L
authors.initials: ML
authors.lastname: Simoons
authors.forename: Mitchell W
authors.initials: MW
authors.lastname: Krucoff
mesh_terms: D015906:Angioplasty, Balloon, Coronary / Q000379:methods*; D018780:Body Surface Potential Mapping / Q000295:instrumentation / Q000379:methods* / Q000592:standards; D003324:Coronary Artery Disease / Q000150:complications / Q000601:surgery* / Q000628:therapy*; D004562:Electrocardiography / Q000295:instrumentation / Q000379:methods* / Q000592:standards; D004566:Electrodes; D006801:Humans; D017202:Myocardial Ischemia / Q000175:diagnosis* / Q000209:etiology / Q000628:therapy*; D015203:Reproducibility of Results; D012146:Rest; D012680:Sensitivity and Specificity