title: High interobserver variability in the assessment of epsilon waves: Implications for diagnosis of arrhythmogenic right ventricular cardiomyopathy/dysplasia.
abstract: BACKGROUND
  Revision of the Task Force diagnostic criteria for arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) has increased their sensitivity for the diagnosis of early and familial forms of the disease. The epsilon wave is a major diagnostic criterion in the context of ARVC/D, which, however, remains not quantifiable and therefore may leave room for substantial subjective interpretation.
  
  
  OBJECTIVE
  The purpose of this study was to assess interobserver agreement in epsilon wave definition and epsilon wave importance for ARVC/D diagnosis.
  
  
  METHODS
  Electrocardiographic (ECG) tracings depicting leads V1, V2, and V3 collected from individuals evaluated for ARVC/D (n = 30) were given to panel members who were asked to respond to the question whether ECG patterns meet epsilon wave definition outlined by the Task Force diagnostic criteria. The prevalence and importance of epsilon waves for ARVC/D diagnosis were assessed in a pooled data set of patients with definite ARVC/D from European and American registries (n = 815).
  
  
  RESULTS
  The number of ECG patterns identified as epsilon waves varied from 5 to 18 per reviewer (median 13 per reviewer). A unanimous agreement was reached for only 10 cases (33%), 2 of which qualified as epsilon waves and 8 as non-epsilon waves by all panel members. From a pooled data set, 106 patients reportedly had epsilon waves (13%). In 105 of 106 patients with epsilon waves (99%), exclusion of epsilon waves from the diagnostic score would not affect the "definite" diagnostic category.
  
  
  CONCLUSIONS
  Interobserver variability in the assessment of epsilon waves is high; however, the impact of epsilon waves on ARVC/D diagnosis is negligibly low. The results urge to exercise caution in the assessment of epsilon waves, especially in patients who would not otherwise meet diagnostic criteria.
authors: Department of Cardiology, Clinical Sciences, Lund University, Lund, Sweden; Arrhythmia Clinic, Skåne University Hospital, Lund, Sweden. Electronic address: Pyotr.Platonov@med.lu.se.
authors: Pyotr G
authors: PG
authors: Platonov
authors: Department of Cardiology, Johns Hopkins Hospital, Baltimore, Maryland.
authors: Hugh
authors: H
authors: Calkins
authors: ICIN-Netherlands Heart Institute, Utrecht, The Netherlands.
authors: Richard N
authors: RN
authors: Hauer
authors: Department of Cardiac, Thoracic and Vascular Sciences, University of Padua Medical School, Padua, Italy.
authors: Domenico
authors: D
authors: Corrado
authors: Danish National Research Foundation Centre for Cardiac Arrhythmia (DARC), Department of Cardiology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark; Department of Clinical Medicine, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark.
authors: Jesper H
authors: JH
authors: Svendsen
authors: Department of Cardiology, Heart Center Osnabrück - Bad Rothenfelde, Niels-Stensen-Kliniken, Marienhospital Osnabrück, Osnabrück, Germany.
authors: Thomas
authors: T
authors: Wichter
authors: Department of Congenital Heart Diseases, Institute of Cardiology, Warsaw, Poland.
authors: Elżbieta Katarzyna
authors: EK
authors: Biernacka
authors: Department of Cardiology, University Heart Center, Zurich, Switzerland.
authors: Ardan M
authors: AM
authors: Saguner
authors: Department of Cardiology, University Medical Center Utrecht, Utrecht, The Netherlands,; Department of Cardiology, Johns Hopkins Hospital, Baltimore, Massachusetts.
authors: Anneline S J M
authors: AS
authors: Te Riele
authors: University of Rochester Medical Center, Rochester, New York.
authors: Wojciech
authors: W
authors: Zareba
mesh_terms: D000328:Adult; D019571:Arrhythmogenic Right Ventricular Dysplasia / Q000175:diagnosis / Q000453:epidemiology; D042241:Early Diagnosis; D004562:Electrocardiography / Q000379:methods / Q000706:statistics & numerical data; D005060:Europe / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D009656:North America / Q000453:epidemiology; D015588:Observer Variation; D015995:Prevalence; D012042:Registries; D015203:Reproducibility of Results
keywords: Arrhythmogenic right ventricular cardiomyopathy/dysplasia; Electrocardiography; Epsilon wave; Interobserver variability; Task Force criteria