Clinical Approach to ARVC

 

Clinical Approach to ARVC

✅ECG features of Arrhythmogenic Right Ventricular Dysplasia (ARVD) with:

🔹 TWI in precordial leads, in absence of RBBB.

🔹 Epsilon wave (most specific finding).

🔹 Localised widened QRS in V1-V3 (due to delayed RV activation).

ARVD:

- Genetic disorder of fibrofatty infiltration of myocardium. 

- Most common symptoms are palpitations/ syncope during exercise. 

- VT with LBBB pattern can become VF, usually triggered by adrenergic stimulation (e.g. exercise).

Arrhythmogenic Right Ventricular Dysplasia (ARVD), also termed Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC), is an inherited myocardial disease characterized by progressive fibrofatty replacement of right ventricular myocardium, leading to ventricular arrhythmias and sudden cardiac death, particularly in young individuals and athletes.

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Definition and Pathophysiology

ARVD is a genetic cardiomyopathy, most commonly inherited in an autosomal dominant pattern. It primarily involves mutations in desmosomal proteins (plakophilin-2, desmoglein-2, desmocollin-2, desmoplakin), resulting in impaired cell-to-cell adhesion.

Loss of myocardial integrity leads to:

Myocyte detachment

Cell death

Replacement with fibrofatty tissue

This process predominantly affects the right ventricle, especially the inflow tract, outflow tract, and apex (“triangle of dysplasia”), causing delayed conduction and arrhythmogenesis.

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ECG Features of ARVD

Electrocardiogram abnormalities are central to diagnosis and often precede structural changes.

1. T-Wave Inversion (TWI)

Present in right precordial leads (V1–V3)

Occurs in the absence of complete RBBB

Reflects abnormal repolarization due to RV myocardial disease

More significant in adults (>14 years)

2. Epsilon Wave (Most Specific Finding)

Small, low-amplitude deflection at the end of QRS complex, best seen in V1–V3

Represents delayed activation of diseased RV myocardium

Often subtle and may require signal-averaged ECG or high-gain recording

3. Localized QRS Widening (V1–V3)

QRS duration prolonged in right precordial leads compared with left leads

Caused by slow conduction through fibrofatty RV tissue

Sometimes described as terminal activation delay ≥55 ms

Other ECG Findings

Low QRS voltage

Fragmented QRS complexes

Ventricular ectopics with LBBB morphology

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Clinical Presentation

ARVD commonly presents in young adults or athletes, often during exertion.

Common Symptoms

Palpitations

Syncope or presyncope (especially during exercise)

Sudden cardiac death as first manifestation in some cases

Ventricular Arrhythmias

Ventricular tachycardia with LBBB morphology (originating from RV)

VT may degenerate into ventricular fibrillation

Arrhythmias are often adrenergically triggered (exercise, emotional stress)

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Diagnosis

Diagnosis is based on Revised Task Force Criteria, incorporating:

ECG abnormalities

Ventricular arrhythmias

Imaging (echo, cardiac MRI)

Histopathology

Family history and genetics

Cardiac MRI is particularly useful to demonstrate:

RV dilation or dysfunction

Fibrofatty infiltration

Late gadolinium enhancement

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Management

Lifestyle

Strict avoidance of competitive sports and strenuous exercise

Medical Therapy

Beta-blockers

Antiarrhythmic drugs (e.g. sotalol, amiodarone)

Device Therapy

Implantable cardioverter-defibrillator (ICD) for:

Sustained VT

Syncope with high-risk features

Survivors of cardiac arrest

Catheter Ablation

For recurrent VT, usually adjunctive, not curative

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Prognosis

ARVD is a progressive disease with variable expression. Early diagnosis and exercise restriction significantly reduce arrhythmic risk. Sudden cardiac death remains the major cause of mortality, especially in undiagnosed young individuals.

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Key Takeaway

ARVD should be suspected in young patients with exertional syncope or VT with LBBB morphology. Epsilon waves, T-wave inversion in V1–V3 without RBBB, and localized QRS widening are hallmark ECG clues that should prompt further evaluation.

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