Arrhythmogenic Right Ventricular Cardiomyopathy

Arrhythmogenic right ventricular cardiomyopathy (ARVC), now often called arrhythmogenic cardiomyopathy, is a genetic disease with progressive fibrofatty replacement of myocardium, causing ventricular arrhythmia and sudden death.

Prevalence about 1 in 2000 to 5000. Autosomal dominant desmosomal gene variants (PKP2 most common, DSP, DSG2, DSC2, JUP), also non desmosomal (TMEM43, PLN, FLNC). Incomplete penetrance, exercise accelerates disease.

Right ventricle predominant, with left ventricular involvement in many (biventricular or left dominant forms).

A leading cause of sudden death in young athletes. Naxos disease (cardiocutaneous, palmoplantar keratoderma, woolly hair) is the recessive form.

Natural history: concealed phase, electrical phase, then right and biventricular failure.

• Palpitations, syncope, presyncope, often exertional, in the second to fourth decade.
• Sudden cardiac death may be the first manifestation.
• Right heart failure in advanced disease.
• Family history of sudden death.

2010 Task Force criteria (major and minor) combine

• Structural and functional right ventricular abnormalities on echo, MRI or angiography.
• Tissue characterisation (fibrofatty replacement on biopsy).
• Repolarisation abnormalities: T wave inversion in V1 to V3 (age 14 or more, without right bundle branch block).
• Depolarisation abnormalities: epsilon wave, late potentials on signal averaged ECG, prolonged terminal activation.
• Arrhythmias: left bundle branch block morphology VT with superior axis, over 500 PVCs per 24 hours.
• Family history and genetic variant.
• Cardiac MRI shows right ventricular dilatation, regional akinesia and late gadolinium enhancement. Holter, exercise testing and electrophysiology study guide risk. Genetic testing of probands with cascade screening. Exclude sarcoidosis, myocarditis, Brugada syndrome and right ventricular outflow tract tachycardia.

• Exercise restriction: avoid competitive and endurance sports. Light activity only.
• Beta blockers (metoprolol 50 to 200 mg, bisoprolol 5 to 10 mg, nadolol, sotalol 80 to 160 mg twice daily) for all patients with arrhythmia and often for gene carriers.
• Antiarrhythmics: amiodarone 200 mg daily, flecainide with beta blocker in selected cases.
• ICD for secondary prevention (sustained VT, VF, syncope) and for primary prevention in high risk patients (ARVC risk calculator, 5 year risk over 10%).
• Catheter ablation (endocardial and epicardial) for recurrent VT and ICD shocks.
• Heart failure therapy: ACE inhibitor, beta blocker, diuretics; anticoagulation for thrombus, atrial fibrillation or aneurysm.
• Cardiac transplantation for refractory failure or intractable arrhythmia.
• Cascade screening of first degree relatives with ECG, echo, MRI and genotype, beginning in adolescence and repeated every 1 to 3 years.