title: Statistical evaluation of reproducibility of automated ECG measurements: an example from arrhythmogenic right ventricular dysplasia/cardiomyopathy clinic.
abstract: BACKGROUND
  Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is characterized by delay in depolarization of the right ventricle, detected by prolonged terminal activation duration (TAD) in V1-V3. However, manual ECG measurements have shown moderate-to-low intra- and inter-reader agreement. The goal of this study was to assess reproducibility of automated ECG measurements in the right precordial leads.
  
  
  METHODS
  Pairs of ECGs recorded in the same day from Johns Hopkins ARVD/C Registry participants [n=247, mean age 35.2±15.6 y, 58% men, 92% whites, 11(4.5%) with definite ARVD/C] were retrospectively analyzed. QRS duration, intrinsicoid deflection, TAD, and T-wave amplitude in the right precordial leads, as well as averaged across all leads QRS duration, QRS axis, T axis, QTc interval, and heart rate was measured automatically, using 12SL TM algorithm (GE Healthcare, Wauwatosa, WI, USA). Intrinsicoid deflection was measured as the time from QRS complex onset to the alignment point of the QRS complex. TAD was calculated as the difference between QRS duration and intrinsicoid in V1, V2, V3. Reproducibility was quantified by Bland-Altman analysis (bias with 95% limits of agreement), Lin's concordance coefficient, and Bradley-Blackwood procedure.
  
  
  RESULTS
  Bland-Altman analysis revealed satisfactory reproducibility of tested parameters. V1 QRS duration bias was -0.10ms [95% limits of agreement -12.77 to 12.56ms], V2 QRS duration bias -0.09ms [-11.13 to 10.96ms]; V1 TAD bias 0.14ms [-13.23 to 13.51ms], V2 TAD bias 0.008ms [-12.42 to 12.44ms].
  
  
  CONCLUSIONS
  Comprehensive statistical evaluation of reproducibility of automated ECG measurements is important for appropriate interpretation of ECG. Automated ECG measurements are reproducible to within 25%.
authors.affiliation: Whiting School of Engineering, Johns Hopkins University, Baltimore, MD, USA.
authors.forename: Timothy
authors.initials: T
authors.lastname: Huang
authors.affiliation: The Division of Cardiology, Department of Medicine, Johns Hopkins Hospital, Baltimore, MD, USA.
authors.forename: Cynthia A
authors.initials: CA
authors.lastname: James
authors.affiliation: The Division of Cardiology, Department of Medicine, Johns Hopkins Hospital, Baltimore, MD, USA.
authors.forename: Crystal
authors.initials: C
authors.lastname: Tichnell
authors.affiliation: The Division of Cardiology, Department of Medicine, Johns Hopkins Hospital, Baltimore, MD, USA.
authors.forename: Brittney
authors.initials: B
authors.lastname: Murray
authors.affiliation: GE Healthcare, Wauwatosa, WI, USA.
authors.forename: Joel
authors.initials: J
authors.lastname: Xue
authors.affiliation: The Division of Cardiology, Department of Medicine, Johns Hopkins Hospital, Baltimore, MD, USA.
authors.forename: Hugh
authors.initials: H
authors.lastname: Calkins
authors.affiliation: The Division of Cardiology, Department of Medicine, Johns Hopkins Hospital, Baltimore, MD, USA.
authors.forename: Larisa G
authors.initials: LG
authors.lastname: Tereshchenko
keywords: ARVD/C; QRS duration; automated measurement; electrocardiogram; reproducibility; terminal activation duration