Arrhythmogenic Right Ventricular Dysplasia (ARVD): A Guide for Junior Doctors

Arrhythmogenic Right Ventricular Dysplasia (ARVD) is a rare but potentially fatal inherited cardiomyopathy characterized by fibrofatty replacement of right ventricular (RV) myocardium. It predisposes patients to ventricular arrhythmias and sudden cardiac death (SCD), especially in young athletes. Here’s a practical guide to help you navigate the key aspects of history-taking, examination, investigation, and management for ARVD.

History-Taking Questions

When evaluating a patient with suspected ARVD, focus on eliciting:

·     Symptoms:

o   Episodes of palpitations: Ask about frequency, duration, and any triggers (e.g., exercise).

o   Syncope or presyncope: Especially during physical activity.

o   Chest pain: Typically non-specific but inquire about association with exertion.

o   Symptoms of heart failure: Dyspnea, orthopnea, or peripheral edema.

·     Family History:

o   History of sudden cardiac death, particularly in individuals under 35 years.

o   Known diagnosis of ARVD or other cardiomyopathies in relatives.

·     Exercise History:

o   Participation in competitive or high-intensity sports.

o   Recent changes in exercise tolerance or performance.

·     Past Medical History:

o   Episodes of myocarditis or unexplained arrhythmias.

o   Previous cardiac investigations showing abnormalities.

·     Medications:

o   Current medications, particularly antiarrhythmics or beta-blockers.

o   Use of performance-enhancing drugs or stimulants.

Examination Findings

While ARVD may not have specific physical findings, focus on:

·     General Appearance:

o   Signs of heart failure: Peripheral edema, jugular venous distension.

o   Cyanosis or pallor (rare but possible if arrhythmias impair perfusion).

·     Vital Signs:

o   Irregular pulse: Suggestive of arrhythmias.

o   Hypotension: May occur in advanced disease or during arrhythmias.

·     Cardiovascular Examination:

o   Displaced apex beat: Suggests ventricular dilation.

o   Third or fourth heart sounds (S3/S4): Indicative of ventricular dysfunction.

o   Murmurs: Tricuspid regurgitation may be present.

·     Other Clues:

o   Skin stigmata of genetic syndromes associated with ARVD (e.g., palmoplantar keratoderma in Naxos disease).

Investigations

Diagnosing ARVD requires a combination of clinical, imaging, and genetic criteria. Use these investigations:

·     Electrocardiogram (ECG):

o   T-wave inversions in V1-V3.

o   Prolonged S-wave upstroke in V1-V3.

o   Epsilon wave: Small positive deflection at the end of QRS complex in V1-V3.

o   Frequent ventricular ectopics or sustained ventricular tachycardia with LBBB morphology.

·     Imaging:

o   Echocardiography: RV dilation, reduced ejection fraction, or regional wall motion abnormalities.

o   Cardiac MRI: Gold standard for identifying fibrofatty infiltration and regional wall motion abnormalities.

·     Genetic Testing:

o   Screen for mutations in desmosomal protein genes (e.g., PKP2, DSP).

o   Offer to first-degree relatives if ARVD is diagnosed.

·     Ambulatory ECG Monitoring:

o   Assess for frequent ventricular arrhythmias or non-sustained ventricular tachycardia.

·     Electrophysiological Studies:

o   Useful if arrhythmia ablation is being considered.

·     Blood Tests:

o   Limited diagnostic value but include baseline tests for arrhythmia workup (e.g., electrolytes, thyroid function).

Management Plan

Management focuses on preventing arrhythmias, SCD, and symptom control.

·     Lifestyle Modifications:

o   Activity Restriction: Avoid competitive sports and strenuous exercise.

o   Genetic Counseling: Essential for affected individuals and their families.

·     Pharmacological Therapy:

o   Beta-blockers (e.g., bisoprolol, metoprolol): First-line for arrhythmia suppression.

o   Antiarrhythmics (e.g., sotalol, amiodarone): For patients with recurrent arrhythmias.

·     Device Therapy:

o   Implantable Cardioverter-Defibrillator (ICD): Indicated for secondary prevention (post-cardiac arrest) or high-risk individuals (e.g., history of sustained VT).

·     Catheter Ablation:

o   Considered in patients with recurrent VT despite medical therapy.

·     Heart Failure Management:

o   ACE inhibitors, diuretics, or mineralocorticoid receptor antagonists in advanced cases.

·     Surgical Options:

o   Rarely needed but heart transplantation may be considered in end-stage disease.