Makindo Medical Notes

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 and may need ICD

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 T wave inversion and 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
• Implantable Cardioverter-Defibrillator (ICD): for those with a history of life-threatening arrhythmias or those at high risk of SCD.
• Beta-blockers: Used to control arrhythmias and reduce the risk of SCD.
• Antiarrhythmics: Sotalol or amiodarone may be used to manage ventricular arrhythmias.
• Heart Failure Medications: Consider ACE inhibitors, ARBs, diuretics
• Anticoagulate: if the patient is in AF
• Catheter Ablation: may be considered in patients with recurrent, symptomatic ventricular tachycardia that is refractory to medication.
• Heart transplantation: may be considered
• Regular follow-up with a cardiologist experienced in managing ARVC is essential.
• Family members should undergo screening if a genetic mutation is identified.

References

• 2019 HRS Expert Consensus Statement on Evaluation, Risk Stratification, and Management of Arrhythmogenic Cardiomyopathy: Moving Toward Precision Medicine
• Guidelines for the diagnosis and management of Arrhythmogenic Right Ventricular Cardiomyopathy