Arrhythmogenic Right Ventricular Dysplasia (ARVD) Topic Review

Introduction

Arrhythmogenic right ventricular dysplasia, or ARVD — also known as arrhythmogenic right ventricular cardiomyopathy, or ARVC — is a genetic condition (autosomal dominant) affecting the desmosomes of the cardiac myocyte.

This results in fatty replacement of the right ventricular myocardium.

As the name implies, the predominant feature of ARVD is arrhythmia, usually in the form of ventricular tachycardia. This ventricular tachycardia is frequently from the right ventricular outflow tract, or RVOT, known as adenosine sensitive ventricular tachycardia. Premature ventricular contractions are common. Sudden cardiac death from ventricular fibrillation is a primary concern.

Diagnosis

Diagnosis is often made using cardiac magnetic resonance imaging, or MRI, along with specific diagnostic criteria developed by the ARVC/D task force in 2010; these criteria are outlined below.

The classic ECG shows inverted T waves in the right precordial leads (V1-V3) with an “epsilon wave” just after the QRS in lead V1, representing early afterdepolarizations. The epsilon wave is frequently described as having a “grassy knoll” appearance.

These same early afterdepolarizations can be detected on a signal averaged ECG, or SAECG, as displayed in the image below. The ECG Archive features a 12-lead ECG example from a patient with ARVD.

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Treatment

Treatment is aimed at preventing sudden cardiac death and relieving symptoms from arrhythmia. Antiarrhythmic drugs are frequently used. Implantable cardioverter defibrillators, or ICDs, are recommended in the following instances:

1. Symptomatic ventricular tachycardia
2. Cardiac arrest
3. First-degree relative with sudden cardiac death
4. Failed drug therapy for ventricular tachycardia (even if asymptomatic)

The 2010 ARVC/D task force describes major and minor criteria. A definite diagnosis is made if two (2) major criteria, one (1) major and two (2) minor criteria, or four (4) minor criteria from the different categories are present.

Structural Abnormalities

• Major - Echocardiography: Regional RV akinesis, dyskinesis or aneurysm and right ventricular enlargement (RVOT > 32 millimeters or 36 mm in parasternal long and short axis views respectively)
• Minor - Echocardiography: Regional RV akinesis, dyskinesis or aneurysm and right ventricular enlargement (RVOT > 29 mm or 32 mm in parasternal long and short axis views respectively)
• Major - MRI: Regional RV akinesis or dyskinesis and an RV ejection fraction less than 40%, or ratio of RV end-diastolic volume to body surface area greater than 110 mL/m2 in males or greater than 100 mL/m2 in females
• Minor - MRI: Regional RV akinesis or dyskinesis and an RV ejection fraction between 40% and 45%, or ratio of RV end-diastolic volume to body surface area greater than 100 mL/m2 in males or greater than 90 mL/m2 in females
• Major - Right ventriculography: Regional RV akinesis, dyskinesis or aneurysm formation

Myocardial Characterization

• Major - Less than 60% myocytes upon RV endomyocardial biopsy; there must be fibrous replacement of the RV free wall myocardium in at least one sample with or without fatty replacement
• Minor - Residual myocytes between 60% and 75%, with fibrous replacement in at least one sample with or without fatty replacement

ECG Abnormalities

• Major - Inverted T waves in V1 to V3 in those aged older than 14 years; no right bundle branch block must be present
• Minor - Inverted T waves in V1 and V2 in those aged older than 14 years; no right bundle branch block must be present
• Minor - Inverted T waves in V1 to V4 in those aged older than 14 years in the presence of a right bundle branch block

Depolarization Abnormalities

• Major - Epsilon waves in leads V1 to V3
• Minor - Late potentials on signal averaged ECG if QRS duration is below 110 milliseconds

Arrhythmia

• Major - Ventricular tachycardia with left bundle branch morphology and superior axis
• Minor - Ventricular tachycardia with left bundle branch morphology and inferior axis
• Minor - Greater than 500 premature ventricular contractions in 24 hours

Family History

• Major - ARVD confirmed in first-degree relative
• Major - Identification of genetic mutation consistent with ARVD
• Minor - ARVD in first-degree relative if unable to confirm the diagnosis
• Minor - Sudden cardiac death at younger than 35 years due to presumed ARVD
• Minor - ARVD in second-degree relative

References:
ARVC/D task force. Diagnosis of Arrhythmogenic Right Ventricular Cardiomyopathy/Dysplasia. Circulation. 2010;doi:10.1161/CIRCULATIONAHA.108.840827.