Arrhythmogenic right ventricular dysplasia (AVRD) is also known as arrhythmogenic right ventricular cardiomyopathy (ARVC). It is:
- An inherited myocardial disease associated with paroxysmal ventricular arrhythmias and sudden cardiac death.
- Characterized pathologically by fibro-fatty replacement of the right ventricular myocardium.
- The second most common cause of sudden cardiac death in young people (after HOCM), causing up to 20% of sudden cardiac deaths in patients < 35 yrs of age.
- Typically inherited as an autosomal dominant trait, with variable penetrance and expression (there is an autosomal recessive form called Naxos Disease, which is associated with woolly hair and skin changes).
- More common in men than women (3:1) and in people of Italian or Greek descent.
- Estimated to affect approximately 1 in 5,000 people overall.
Diagnosis of ARVD
There is no single diagnostic test for ARVD. The diagnosis is made using a combination of clinical, electrocardiographic and radiological features, as defined by the (horribly complicated) 2010 Task Force Criteria.
- ARVD causes symptoms due to ventricular ectopic beats or sustained ventricular tachycardia (with LBBB morphology) and typically presents with palpitations, syncope or cardiac arrest precipitated by exercise.
- The first presenting symptom may be sudden cardiac death.
- Over time, surviving patients also develop features of right ventricular failure, which may progress to severe biventricular failure and dilated cardiomyopathy.
- There is usually a family history of sudden cardiac death.
ARVD is associated with characteristic ECG abnormalities:
- Epsilon wave (most specific finding, seen in 30% of patients)
- T wave inversions in V1-3 (85% of patients)
- Prolonged S-wave upstroke of 55ms in V1-3 (95% of patients)
- Localised QRS widening of 110ms in V1-3
- Paroxysmal episodes of ventricular tachycardia with a LBBB morphology (i.e. right ventricular VT).
Prolonged S-wave upstroke and localized QRS widening in V2
Some authors recommend recording ECG rhythm strips at double speed and double amplitude to enhance the detection of some of these features (click here for a description of how to do this).
Right Ventricular VT with LBBB morphology
Right ventricular VT is discussed in more detail here.
- Echocardiography is the first-line investigation, and may demonstrate a dilated, hypokinetic right ventricle with prominent apical trabeculae and dilatation of the RV outflow tract.
- The imaging modality of choice in many centres is cardiovascular MRI, which can accurately demonstrate structural and functional features of ARVD such as fibrofatty infiltration and thinning of the RV myocardium, RV aneurysms, RV dilatation, regional wall motion abnormalities and global systolic dysfunction.
- Other imaging modalities such as CT scanning and right ventricular contrast angiography may be used to make the diagnosis where MRI is unavailable, but have the disadvantages of high radiation burden and/or invasive technique.
- Histological diagnosis, either via endomyocardial biopsy or at autopsy, provides a definitive diagnosis but is impractical, and for those patients diagnosed at post-mortem… far too late!
Patients with ARVD are considered to be at high risk of sudden death if they have any of the following:
- A history of syncope due to cardiac arrest
- Recurrent arrhythmias not suppressed by anti-arrhythmic drug therapy
- A family history of cardiac arrest in first degree relatives
- In patients with no high risk features, initial treatment is with anti-arrhythmic drugs such as beta-blockers or amiodarone to suppress cathecholamine-triggered ventricular arrhythmias. Currently, the most effective drug for this is sotalol.
- Patients with any high risk features require urgent insertion of an implantable cardioverter-defibrillator (ICD).
- In patients with persistent symptomatic arrhythmias, radiofrequency ablation of conduction pathways may be attempted.
- Heart failure is treated in the usual way, with diuretics, ACE inhibitors and anticoagulants. In severe cases, cardiac transplantation may be required.
Professor Sanjay Sharma discusses the ECG findings in ARVC:
- ECG BASICS — Waves, Intervals, Segments and Clinical Interpretation
- ECG CLINICAL CASES — Your favourite ECG’s placed in clinical context with a challenging Q&A approach
- ECG and Cardiology Eponymous Syndromes — Cheats guide to eponymous emancipation
- ECG Exam Template — a framework for the FACEM part 2 exam.
- ECG Reference Sites on the WEB — the best of the rest
- Anderson EL. Arrhythmogenic right ventricular dysplasia. Am Fam Physician. 2006 Apr 15;73(8):1391-8 [Full Text].
- ARVD.com. The website of the Johns Hopkins ARVD Patient Registry based in Baltimore, Maryland.
- Perez Diez D, Brugada J. Diagnosis and Management of Arrhythmogenic Right Ventricular Dysplasia: An article from the E-Journal of the ESC Council for Cardiology Practice, European Society of Cardiology 2008 [Full text].
- Protonotarios N, Tsatsopoulou A. Naxos disease. Indian Pacing Electrophysiol J. 2005 Apr 1;5(2):76-80. PMID:Wrong Shortcode Contents [Full text]
- Surawicz B, Knilans T. Chou’s Electrocardiography in Clinical Practice (6th edition), Saunders 2008.
- Wagner, GS. Marriott’s Practical Electrocardiography (11th edition), Lippincott Williams & Wilkins 2007.