Arrhythmogenic Right Ventricular Cardiomyopathy

Formerly called arrhythmogenic right ventricular dysplasia, arrhythmogenic right ventricular cardiomyopathy (ARVC) is characterised by progressive fibro-fatty replacement of right ventricular myocardium with progressive effects on the right ventricle, a strong familial transmission, and presentation with symptomatic arrhythmias or sudden death.¹ The precise aetiology remains unknown.

There are separate articles which discuss Cardiomyopathies, Hypertrophic Cardiomyopathies, Dilated Cardiomyopathy and Restrictive Cardiomyopathy.

• Most often presents in adolescence and early adulthood.
• More common in males.
• Presents as familial disease in at least 30% of patients: autosomal dominant inheritance is typical.²

Dependent on which phase of disease progression:

• Concealed phase:
  • Subtle right ventricular changes, with or without minor ventricular arrhythmias.
  • These may occasionally be the first manifestation as sudden death, usually in the young engaged in competitive sports or intense exercise.
• Overt electrical disorder:
  • Symptomatic right ventricular arrhythmias associated with functional and structural abnormalities of the right ventricle.
  • Usually presents with palpitations or syncope.
  • Arrhythmias and sudden death are common. Previously undiagnosed ARVC accounts for about 20% of cardiac sudden deaths.
• Right ventricular failure:
  • Extension of disease to the whole of the right ventricle causes dysfunction.
• Biventricular pump failure - end stage:
  • Left ventricular involvement leads to heart failure and may mimic dilated cardiomyopathy.

A Task Force set up by the European and International Society of Cardiology has proposed diagnostic criteria in some detail.³

• Assessment of cardiac function and disease aetiology:
  • Blood tests, including full blood count, ESR/CRP, renal function and electrolytes, liver function tests; cardiac enzymes may be appropriate, depending on presentation
  • ECG - the most common finding being ventricular arrhythmias with LBBB morphology
  • Chest x-ray
  • Echocardiogram
  • Cardiac catheterisation
  • MRI scan
  • Heart biopsy
• Genetic assessment

• For patients with well tolerated or non life-threatening ventricular arrhythmias, beta-blockers, such as sotalol, or amiodarone with/without beta-blocker, are the most effective drugs with a relatively low proarrhythmic risk.
• For sustained VT or VF, serial therapeutic drug trials are used, using programmed ventricular stimulation to assess effectiveness.
• Patients who remain inducible of arrhythmias usually require an implantable cardioverter defibrillator, except for rare cases with localised disease where catheter ablation may be an option.
• Ablation can have up to a 90% success rate in the short term, but a 60% recurrence rate which may lead to sudden death.
• In patients who are not inducible, and present in cardiac arrest or syncope, an automatic implantable cardioverter-defibrillator is the first option, and is the most effective intervention in prevention of arrhythmic sudden death.
• Treatment of heart failure.
• Heart transplantation may need to be considered in refractory cases in end stage failure.

• Arrhythmogenic right ventricular dysplasia tends to be progressive with deterioration of right ventricular function.
• The left ventricle may become involved with progression of the degenerative process.
• The death rate is approximate 2.5% per year.⁴