title: Clinical Significance of Epsilon Waves in Arrhythmogenic Cardiomyopathy.
abstract: BACKGROUND
  Epsilon waves are hallmark features of arrhythmogenic cardiomyopathy (ACM) but information about their clinical significance is variable. We evaluated epsilon wave prevalence, characteristics, and their clinical significance in an ACM population.
  
  
  RESULTS
  Eighty-six unselected patients fulfilling the 2010 Task Force criteria were enrolled. Seventy-six of them were carriers of desmosomal mutations. All subjects were serially evaluated with standard 12-lead ECG and 2-dimensional echocardiography. Epsilon waves were evaluated in all precordial and inferior leads. Novel parameters assessed included their duration and precordial/inferior lead extension. Twenty-five subjects (29%) had epsilon waves that were present in lead V3 and beyond in 9, and in the inferior leads in 7. Epsilon waves were associated with right ventricular outflow tract (RVOT) (P = 0.001) but not RV posterior wall (P = 0.21), RV apex (P = 0.30), or left ventricular (P = 0.94) wall motion abnormalities. Patients with epsilon waves had increased RVOT diameter (P < 0.0001). Extension of epsilon waves in lead V3 and beyond was associated with increased epsilon wave duration (P = 0.002) and RVOT diameter (P = 0.04). The duration of epsilon waves was positively correlated with RVOT diameter (r = 0.70, P = 0.0001). Epsilon waves were also associated with episodes of sustained ventricular tachycardia (P = 0.004) but not with heart failure (P = 0.41) or sudden cardiac death (P = 0.31).
  
  
  CONCLUSIONS
  Detection of epsilon waves on 12-lead ECG reflects significant RVOT involvement, which was associated with episodes of sustained ventricular tachycardia but not sudden cardiac death.
authors.affiliation: Nikos Protonotarios Medical Centre, Naxos, Greece.
authors.forename: Alexandros
authors.initials: A
authors.lastname: Protonotarios
authors.affiliation: 1st Department of Cardiology, University of Athens Medical School, Athens, Greece.
authors.forename: Aris
authors.initials: A
authors.lastname: Anastasakis
authors.affiliation: Nikos Protonotarios Medical Centre, Naxos, Greece.
authors.forename: Adalena
authors.initials: A
authors.lastname: Tsatsopoulou
authors.affiliation: Department of Cardiology, Nicosia General Hospital, Nicosia, Cyprus.
authors.forename: Loizos
authors.initials: L
authors.lastname: Antoniades
authors.affiliation: 2nd Department of Cardiology, Evangelismos General Hospital, Athens, Greece.
authors.forename: Efstathia
authors.initials: E
authors.lastname: Prappa
authors.affiliation: Institute of Cardiovascular Science, University College London and The Heart Hospital, University College London Hospitals Trust, London, UK.
authors.forename: Petros
authors.initials: P
authors.lastname: Syrris
authors.affiliation: 1st Department of Cardiology, University of Athens Medical School, Athens, Greece.
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Tousoulis
authors.affiliation: Institute of Cardiovascular Science, University College London and The Heart Hospital, University College London Hospitals Trust, London, UK.
authors.forename: William J
authors.initials: WJ
authors.lastname: McKENNA
authors.affiliation: Nikos Protonotarios Medical Centre, Naxos, Greece.
authors.forename: Nikos
authors.initials: N
authors.lastname: Protonotarios
keywords: arrhythmogenic right ventricular cardiomyopathy; arrhythmogenic right ventricular dysplasia; epsilon waves; right bundle branch block; sudden cardiac death