Epsilon Wave on ECG
An epsilon wave on ECG is a hallmark sign of arrhythmogenic right ventricular cardiomyopathy (ARVC) and mandates immediate comprehensive cardiac evaluation under cardiologist supervision, as this represents a life-threatening inherited cardiac disease causing sudden cardiac death in young individuals. 1
ECG Characteristics
The epsilon wave appears as:
- Terminal notches in the QRS complex or low-frequency waves occurring after the QRS ends 1
- Associated with localized QRS prolongation (>110 ms) in right precordial leads V1-V3 1
- Frequently accompanied by delayed S-wave upstroke (>55 ms) in V1-V2 1
Immediate Diagnostic Workup Required
All young individuals with epsilon waves require the following comprehensive evaluation 1:
Essential Testing
- Echocardiography to assess for structural abnormalities, particularly right ventricular dilation and wall motion abnormalities 1
- Cardiac MRI - this is the gold standard for detecting fibro-fatty replacement of myocardium characteristic of ARVC 1
- 24-hour Holter monitoring to detect ventricular arrhythmias including premature ventricular contractions, couplets, triplets, and non-sustained ventricular tachycardia 1
- Exercise stress testing to assess arrhythmic risk and potentially unmask epsilon waves that may not be visible at rest 1, 2
Additional Considerations
- Genetic testing should be pursued when clinical suspicion is high, particularly given the inherited nature of ARVC 1
- Detailed family history is critical - family history of sudden cardiac death significantly increases risk 1
Clinical Significance and Risk Stratification
Epsilon waves correlate strongly with right ventricular outflow tract (RVOT) involvement and sustained ventricular tachycardia episodes 1, 3. However, they do not independently predict sudden cardiac death 1.
Key prognostic findings 3:
- Patients with epsilon waves demonstrate increased RVOT diameter 3
- Extension of epsilon waves to lead V3 and beyond indicates more extensive disease and larger RVOT diameter 3
- Epsilon wave duration positively correlates with RVOT diameter (r = 0.70) 3
Management Strategy
ICD Implantation
ICD implantation is a Class I recommendation for ARVC patients with documented sustained ventricular tachycardia or ventricular fibrillation who have reasonable expectation of survival with good functional status for >1 year 1
Antiarrhythmic Therapy
- Amiodarone or sotalol can be effective (Class IIa) for treating sustained VT/VF when ICD implantation is not feasible 1
Sports Participation
Athletes with diagnosed ARVC must abstain from all competitive sports due to high risk of exercise-triggered sudden cardiac death 1
Critical Pitfalls to Avoid
Differential Diagnosis Considerations
While epsilon waves are hallmark features of ARVC, they can appear in other conditions 4:
- Posterior myocardial infarction 4
- Right ventricular infarction 4
- Infiltrative diseases and sarcoidosis 4
- Brugada Syndrome 4
- Repaired Tetralogy of Fallot 5
- Hypothermia 4
Do not dismiss epsilon waves as benign without thorough evaluation, even if the patient is asymptomatic 1
Exercise Testing Nuance
Exercise testing may unmask epsilon waves not visible on resting ECG in asymptomatic mutation carriers, making it a valuable diagnostic tool 2
Mimicking ACS
Epsilon waves can be masked by ST-segment elevation after cardioversion from sustained VT, potentially mimicking acute coronary syndrome 6. Maintain high clinical suspicion for ARVD/C even when presentation suggests ACS 6.
Long-term Surveillance
ARVC is a progressive disease with variable penetrance and age-related expression, requiring ongoing monitoring 1: