Volume 13, Issue 1, Pages 208-216 (January 2016) High interobserver variability in the assessment of epsilon waves: Implications for diagnosis of arrhythmogenic right ventricular cardiomyopathy/dysplasia  Pyotr G. Platonov, MD, PhD, FHRS, Hugh Calkins, MD, Richard N. Hauer, MD, PhD, Domenico Corrado, MD, PhD, Jesper H. Svendsen, MD, DMSci, Thomas Wichter, MD, Elżbieta Katarzyna Biernacka, MD, PhD, Ardan M. Saguner, MD, Anneline S.J.M. te Riele, MD, Wojciech Zareba, MD  Heart Rhythm  Volume 13, Issue 1, Pages 208-216 (January 2016) DOI: 10.1016/j.hrthm.2015.08.031 Copyright © 2016 Heart Rhythm Society Terms and Conditions

Figure 1 Electrocardiographic (ECG) reading results by individual panel members (R1-R7). Each line corresponds to 1 ECG pattern. Gray cells indicate the pattern being recognized as an epsilon wave by an individual panel member. Numbers at the bottom indicate the total number of ECG patterns recognized as epsilon waves per reviewer. Heart Rhythm 2016 13, 208-216DOI: (10.1016/j.hrthm.2015.08.031) Copyright © 2016 Heart Rhythm Society Terms and Conditions

Figure 2 Electrocardiographic patterns classified as epsilon waves by all (A and B) or majority of (≤6) reviewers (C and D). Heart Rhythm 2016 13, 208-216DOI: (10.1016/j.hrthm.2015.08.031) Copyright © 2016 Heart Rhythm Society Terms and Conditions

Figure 3 Electrocardiographic patterns unanimously considered as not meeting epsilon-wave definition. Heart Rhythm 2016 13, 208-216DOI: (10.1016/j.hrthm.2015.08.031) Copyright © 2016 Heart Rhythm Society Terms and Conditions

Figure 4 Electrocardiographic patterns for which no agreement could be reached; that is, they were recognized as epsilon waves by 4 of 7 panelists. Heart Rhythm 2016 13, 208-216DOI: (10.1016/j.hrthm.2015.08.031) Copyright © 2016 Heart Rhythm Society Terms and Conditions

Figure 5 Similar electrocardiographic (ECG) patterns with a notch after the end of the QRS complex in lead V1 that have been judged differently, depending on the notch location with regard to the global end of the QRS complex estimated from the available right precordial leads. Numbers under the ECG tracings indicate the number of panelists who positively identified the ECG patterns as epsilon waves. Heart Rhythm 2016 13, 208-216DOI: (10.1016/j.hrthm.2015.08.031) Copyright © 2016 Heart Rhythm Society Terms and Conditions

Figure 6 Assessment of epsilon wave importance for arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) diagnosis in the pooled data set of 105 patients with ARVC/D and epsilon waves out of 815 patients with definite ARVC/D from 5 large ARVC/D registries (see Table 1 for details). Exclusion of the major and minor depolarization criteria from the diagnostic score would not affect the definite diagnostic category in 95 patients (90%). Of the 10 patients who would loose their definite ARVC/D diagnostic category, 9 still have a positive terminal activation duration criterion and therefore would still meet diagnostic criteria for ARVC/D. In total, only 1 of 105 patients with epsilon waves had ARVC/D diagnosis dependent on the presence of epsilon waves. Heart Rhythm 2016 13, 208-216DOI: (10.1016/j.hrthm.2015.08.031) Copyright © 2016 Heart Rhythm Society Terms and Conditions

Figure 7 Progression of ventricular depolarization abnormality in a patient with arrhythmogenic right ventricular cardiomyopathy/dysplasia over the 10-year follow-up period. It is first seen as a fractionation of the terminal part of the QRS complex with prolonged terminal activation duration (1989), but 10 years later (1999) it appears as a distinct epsilon wave observed in all chest leads, with particularly high amplitude in leads V1-V3. Courtesy of Anneli Svensson. Heart Rhythm 2016 13, 208-216DOI: (10.1016/j.hrthm.2015.08.031) Copyright © 2016 Heart Rhythm Society Terms and Conditions