title: Estimation performance of a reduced lead system during continuous 12-lead ECG ST-segment monitoring.
abstract: BACKGROUND
  Reduced lead systems utilizing patient-specific transformation weights have been reported to achieve superior estimates than those utilizing population-based transformation weights. We report upon the effects of ischemic-type electrocardiographic changes on the estimation performance of a reduced lead system when utilizing patient-specific transformation weights and population-based transformation weights.
  
  
  METHODS
  A reduced lead system that used leads I, II, V2 and V5 to estimate leads V1, V3, V4, and V6 was investigated. Patient-specific transformation weights were developed on electrocardiograms containing no ischemic-type changes. Patient-specific and population-based transformations weights were assessed on 45 electrocardiograms with ischemic-type changes and 59 electrocardiograms without ischemic-type changes.
  
  
  RESULTS
  For patient-specific transformation weights the estimation performance measured as median root mean squared error values (no ischemic-type changes vs. ischemic-type changes) was found to be (V1, 27.5 μV vs. 95.8 μV, P<.001; V3, 33.9 µV vs. 65.2 µV, P<.001; V4, 24.8 μV vs. 62.0 μV, P<.001; V6, 11.7 μV vs. 51.5 μV, P<.001). The median magnitude of ST-amplitude difference 60 ms after the J-point between patient-specific estimated leads and actual recorded leads (no ischemic-type changes vs. ischemic-type changes) was found to be (V1, 18.9 μV vs. 61.4 μV, P<.001; V3, 14.3 μV vs. 61.1 μV, P<.001; V4, 9.7 μV vs. 61.3 μV, P<.001; V6, 5.9 μV vs. 46.0 μV, P<.001).
  
  
  CONCLUSIONS
  The estimation performance of patient-specific transformations weights can deteriorate when ischemic-type changes develop. Performance assessment of patient-specific transformation weights should be performed using electrocardiographic data that represent the monitoring situation for which the reduced lead system is targeted.
authors.affiliation: School of Computing and Mathematics and Computer Science Research Institute, University of Ulster, Belfast, UK. queldenring_daniel@gmx.de
authors.forename: Daniel
authors.initials: D
authors.lastname: Guldenring
authors.forename: Dewar D
authors.initials: DD
authors.lastname: Finlay
authors.forename: Stefan P
authors.initials: SP
authors.lastname: Nelwan
authors.forename: Chris D
authors.initials: CD
authors.lastname: Nugent
authors.forename: Mark P
authors.initials: MP
authors.lastname: Donnelly
authors.forename: Raymond R
authors.initials: RR
authors.lastname: Bond
mesh_terms: D000328:Adult; D000465:Algorithms; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D004562:Electrocardiography / Q000295:instrumentation* / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity