Arrhythmogenic Right Ventricular Dysplasia (ARVD)

Overview of ARVD

Autosomal dominant genetic disorder of myocardium in which there is fatty infiltration of the right ventricular free wall, predisposing to paroxysmal ventricular arrhythmias, sudden cardiac death, and biventricular failure

  • Second most common cause of sudden cardiac death in young people (after HOCM), accounting for up to 10% of sudden cardiac deaths in patients < 65 yrs of age
  • Prevalence ~ 1 in 5000
  • Diagnosis is difficult and relies on a combination of clinical, electrocardiographic and radiological features, as defined by the (horribly complicated) 2010 Task Force Criteria

ECG features
  • T wave inversion in right precordial leads V1-3, in absence of RBBB (85% of patients)
  • Epsilon wave (most specific finding, seen in 50% of patients)
  • Localised QRS widening in V1-3 (> 110ms)
  • Prolonged S wave upstroke of 55ms in V1-3
  • Ventricular ectopy of LBBB morphology, with frequent PVCs > 1000 per 24 hours
  • Paroxysmal episodes of ventricular tachycardia (VT) with LBBB morphology (RVOT tachycardia)

Epsilon Waves
Epsilon wave in V1, due to RV conduction delay

Prolonged S-wave upstroke in ARVD
Prolonged S-wave upstroke in V2 with localized QRS widening

Note: Some authors recommend recording ECG rhythm strips at double speed (50 mm/second) and double amplitude (20mV/10mm) to enhance the detection of some of these features


Clinical Features
  • ARVD causes symptoms due to ventricular ectopic beats or sustained VT (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 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

Fontaine leads

Fontaine bipolar precordial leads (F-ECG) are used to increase the sensitivity of epsilon wave detection. Leads are placed as shown:

  • Right Arm (RA) over the manubrium;
  • Left Arm (LA) over the xiphoid process;
  • and Left Leg (LL) in the standard V4 position (5th ICS MCL).

Instead of regular leads I, II, and III, there are now three bipolar chest leads that are termed FI, FII, and FIII. These record potentials developed in the right ventricle, from the infundibulum to the diaphragm.

The vertical bipolar lead FI (similar to aVF) magnifies the atrial potentials and can be used to record:

  • Epsilon waves
  • Search for AV dissociation in ventricular tachycardia
  • Study abnormal atrial rhythms when the P waves are too small on regular leads
Fontaine bipolar precordial lead electrocardiography (F-ECG)
Fontaine bipolar precordial leads (F-ECG)

ECG Examples
Example 1
Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) ECG ARVD

Baseline ECG of a patient with Arrhythmogenic Right Ventricular Dysplasia (ARVD), demonstrating:

  • T-wave inversion in precordial and inferior leads, without RBBB pattern
  • Epsilon wave in V1
  • Localised widening of QRS in V1-2
Example 2
ECG Right Ventricular VT with LBBB morphology

Right Ventricular Outflow Tract (RVOT) Tachycardia, demonstrated by:

  • Regular broad complex tachycardia with LBBB morphology
  • Inferior axis (+90 degrees)
  • AV dissociation seen in V1
  • Read more about RVOT tachycardia

Imaging
  • 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
  • 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!

Risk Assessment

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

Treatment Options

Primary treatment involves arrhythmia suppression and prevention of thrombus formation:

  • 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. Warfarin is often recommended to prevent thrombus formation due to RV hypokinesis
  • In patients with persistent symptomatic arrhythmias, radiofrequency ablation of conduction pathways may be attempted. However, progression of disease means over half ocases recur
  • Patients with any high risk features require urgent insertion of an implantable cardioverter-defibrillator (ICD)
  • Heart failure is treated in the usual way, with diuretics, ACE inhibitors and anticoagulants. In severe cases, cardiac transplantation may be required


Learn From The Experts!

Professor Sanjay Sharma explains ARVD


References

Advanced Reading

Online

Textbooks


LITFL Further Reading

ECG LIBRARY 700

ECG LIBRARY

Electrocardiogram

MBBS (UWA) CCPU Emergency Medicine Advanced Trainee based in Melbourne, Australia. Co-author of the LITFL ECG Library. Likes Ultrasound, Echo, ECGs, and anything and everything with caffeine. Part of the 2021 ANZCEN Clinician Educator Incubator Programme | @rob_buttner | ECG Library |

Emergency Physician in Prehospital and Retrieval Medicine in Sydney, Australia. He has a passion for ECG interpretation and medical education | ECG Library |

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