Related Subjects:
|Ventricular Tachycardia
|Right Ventricular Outflow Tract Tachycardia
|Resuscitation - Adult Tachycardia Algorithm
|Automatic Implantable Cardioverter Defibrillator (AICD)
ARVC is a member of the group of arrhythmogenic cardiomyopathies which have in common a risk of sudden cardiac death (SCD) due to a malignant ventricular arrhythmia
About
- Also known as Arrhythmogenic Right ventricular cardiomyopathy
- Studies show that LV involved more involved with time.
- Around 1 in 10,000 people are thought to have ARVC
Genetics
- Autosomal dominant with over 8 identified genes
- Enquire about a family history
- Cause of sudden cardiac death in young people
Genes
- Plakophilin-2 (PKP2)
- Desmoplakin (DSP)
- Desmoglein-2 (DSG2)
- Desmocollin-2 (DSC2)
- Plakoglobin (JUP)
- Transmembrane protein 43 (TMEM43)
- Ryanodine receptor 2 (RYR2)
Epsilon waves
Aetiology
- ARVD/C is often caused by mutations in the desmosomal proteins
- Fibrofatty replacement of the myocardium usually RV more than LV
- The ventricular walls become thinned. Risk of arrhythmias and heart block
- There are biventricular and primarily left ventricular (LV) subtypes
Clinical
- Palpitations and fluttering may be due to ectopics or AF or VT
- Exertional chest pain and dyspnoea due to heart failure
- Abdominal pain, Dizziness and fatigue
- Widely split S2 and an S3 or S4 heart sound may be noted.
Complications
- Arrhythmias; Ectopics, AF, VT, VF
- Heart failure
- Sudden cardiac death
- Bradycardia and heart block
Investigations
- ECG: VT with LBBB pattern, Epsilon waves with incomplete RBBB and mild ST elevation may be seen. Low QRS voltage in the limb leads is a marker of LV involvement.
- Echocardiography: immediate test is useful in undiagnosed patient and may demonstrate a dilated, hypokinetic right ventricle with prominent apical trabeculae and dilatation of the RV outflow trac
- Cardiac MRI: the technique of choice to show right ventricular wall motion and outflow tract problems or infiltrative processes. MRI should include tissue characterization, which may be definitively indicative of fibro-fatty replacement in the right or left ventricles.
- Endomyocardial biopsy and endocardial voltage mapping are invasive and difficult to interpret; these should be reserved for selected patients in which diagnosis is elusive.
- Holter or other monitoring for arrhythmias should consider the possibility of either RV or LV origins in the various disease subtypes
Differential Diagnosis
- RV outflow tract ventricular tachycardia
- Brugada syndrome
- RV volume overload due to congenital heart lesions
ECG showing Epsilon waves
Screening
- Both a 12-lead and, if possible, a signal-averaged ECG should be obtained on all first-degree relatives
Management
- Life style: balanced diet, avoid caffeine, weight control, minimise alcohol, stop smoking. Exercise should be within moderate intensity.
- Sustained VT : follow Adult Tachycardia algorithm for VT see link above
- The use of Automatic Implantable cardioverter-defibrillators should be considered after full expert risk analysis
- Beta-blockers, Sotalol and Amiodarone have been the most
commonly used antiarrhythmic agents. There are no data however that drug treatment improves survival in the absence of sustained ventricular arrhythmias, so that the real management issue is the timing and indications for an AICD. Ablation may also be considered in selected cases.
- Anticoagulate AF
- Heart transplantation may be considered
References