Can Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) present with an epsilon wave in lead II but not in leads V1-V4 on an electrocardiogram (ECG)?

Epsilon Waves in ARVC: Atypical Lead Distribution

Yes, ARVC can present with epsilon waves in atypical leads including lead II, though this is uncommon and the classic presentation involves leads V1-V3. 1

Classic vs. Atypical Epsilon Wave Distribution

The typical epsilon wave pattern in ARVC appears in the right precordial leads:

• Epsilon waves in leads V1-V3 are the classic finding and represent a major diagnostic criterion for ARVC, occurring as a highly specific ECG marker of the disease 1
• The epsilon wave reflects delayed right ventricular activation due to fibrofatty replacement of myocardium, typically manifesting in right precordial leads where RV electrical activity is most prominent 2

However, ECG changes in ARVC reflect the specific myocardial areas of disease involvement, and the distribution can vary based on which portions of the ventricle are affected 1:

• T-wave changes in inferior leads (II, III, aVF) often reflect RV infero-posterior wall involvement 1
• When left ventricular involvement is present, abnormalities extend to lateral leads (V4-V6, I, aVL) 1, 3
• The disease is progressive and heterogeneous, starting from epi- or mid-myocardium and potentially affecting different regions 1

Clinical Interpretation of Your ECG Findings

Your specific ECG pattern warrants careful consideration:

• T-wave inversion in V1-V4 is consistent with ARVC involving the RV free wall, representing one of the most frequent ECG abnormalities in this disease (occurring in approximately 29% of patients) 3
• An epsilon wave in lead II without V1-V4 involvement is atypical but could represent predominant involvement of the RV inferior wall 1
• The sinus bradycardia and normal QTc (423 ms) are non-specific findings 1

Critical Diagnostic Considerations

A diagnosis based solely on imaging criteria with a completely normal ECG should be considered suspicious, as ECG changes are typically the first disease manifestation, preceding structural abnormalities 1, 3. However, the reverse concern applies here:

• Exercise testing may unmask epsilon waves that are not apparent at rest, and has been shown to uncover epsilon waves in asymptomatic mutation carriers 4, 5
• Dynamic ECG changes occur in approximately 23% of ARVC patients, with epsilon waves appearing or disappearing over time 5
• High interobserver variability exists in epsilon wave identification (only 33% unanimous agreement among experts in one study), so the finding should be interpreted cautiously 6

Recommended Diagnostic Workup

Given your ECG findings, comprehensive evaluation is warranted:

• Echocardiography is the minimum required investigation for any suspected ARVC based on ECG abnormalities 1, 7
• Cardiac MRI should be performed as it is superior to echocardiography for detecting ARVC and is recommended for anterior T-wave inversion patterns 1
• Exercise ECG testing may reveal additional epsilon waves or arrhythmias not present at rest 1, 4
• Minimum 24-hour ECG monitoring to assess for ventricular arrhythmias, which are often present without symptoms 1
• Signal-averaged ECG (SAECG) provides markers of slow conduction, though it is neither highly sensitive nor specific 1, 3

Prognostic Implications

The presence of epsilon waves carries significant prognostic weight:

• Epsilon wave was the only independent predictor of the composite endpoint of sudden cardiac death, heart failure-related death, or heart transplant (OR 20.9) in one longitudinal study 2
• However, in 99% of cases with epsilon waves, the diagnosis of "definite ARVC" was already established by other criteria, suggesting epsilon waves typically appear in more advanced disease 6

Important Caveats

• Serial ECG monitoring is essential as ECG abnormalities can develop or change over time, sometimes preceding structural changes by months to years 8, 7, 5
• A single normal echocardiogram does not exclude future development of cardiomyopathy, particularly in early disease stages 7
• The extent of ECG abnormalities generally correlates with disease severity, though a normal ECG does not exclude ARVC, especially in mild or early forms 9