High Interobserver Variability in the Assessment of Epsilon Waves: Implications for Diagnosis of Arrhythmogenic Right Ventricular Cardiomyopathy/Dysplasia.

Platonov PG, Calkins H, Hauer RN, Corrado D, Svendsen JH, Wichter T, Katarzyna Biernacka E, Saguner AM, Te Riele A, Zareba W.

Heart Rhythm. 2015 Aug 21. [Epub ahead of print]

Being a major diagnostic criterion in the context of arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D), epsilon wave has great impact on the diagnostic score, which can be pivotal in patients with minimal clinical manifestations of the disease or family members undergoing screening for ARVC/D.  However, it remains not quantifiable and therefore may leave room for substantial subjective interpretation.

ISHNE Epsilon Wave Initiative was aimed to assess interobserver variability in regard to assessment of ECG patterns representing right precordial leads in subjects undergoing clinical screening for ARVC/D.

The results of the study demonstrate that even among ARVC/D experts, that there is unacceptably high interobserver variability in the interpretation of whether an epsilon wave is present or absent. The results of this study also showed that presence or absence of an episilon wave has little impact on diagnosis of ARVC/D in experienced centers. This reflects the fact that epsilon waves, when present, are late manifestations of the disease. As a result, the diagnosis of ARVC/D in these individuals can be determined based on other 2010 Task Force criteria. ARVC/D patients are very unlikely to express an epsilon wave as an isolated finding and as noted above when present is accompanied by other clinical manifestations that are sufficient for a definite ARVC/D diagnosis.

Our findings urge extreme caution in interpretation of ECG patterns in individuals assessed for ARVC/D and suggest that an isolated epsilon wave should not be a major criterion in cases when the only other finding is family history. Implementation of our study findings in clinical practice is likely to improve accuracy of ARVC/D diagnostics using the revised 2010 Task Force criteria and reduce the risk of inappropriate ARVC/D diagnosis. 

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