Arrhythmogenic Right Ventricular Cardiomyopathy

Other Names

• Arrhythmogenic Right Ventricular Dysplasia (ARVD)

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Background

• This page describes Arrhythmogenic Right Ventricular Dysplasia (ARVD)
  • It is an inherited heart muscle disease characterized by progressive fibrofatty replacement of the myocardium that predisposes to ventricular tachycardia and sudden cardiac death in young individuals and athletes

History

• It was first identified in 1977 by Guy Fontaine

Epidemiology

• In the general population, the prevalence of ARVC/D is 1 per 2500 to 1 per 5000
• The presentation is highly variable within families with mean age affected being 31 years
• It occurs in young adults and has a male to female ratio of 2.7 to 1
• It is responsible for 11% of all cases of sudden cardiac death, and 22% of cases among athletes

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Pathophysiology

• There are 3 current variants:
  • The classic and most common - isolated RV involvement
  • Biventricular involvement including balanced, dominant right, and dominant left
  • Isolated LV involvement

• Typically inherited in an autosomal dominant pattern
• There are 5 established disease causing genes that encode desmosomal proteins leading to impaired desmosome function :
  • Plakoglobin
  • Desmoplakin
  • Plakophilin-2
  • Desmoglein
  • Desmocillin
• When these defected desmosomes are subjected to cardiac stress, it leads to myocyte detachment and death, which ultimately results in fibrofatty replacement of injured myocytes
• It is a progressive disease leading to dilated cardiomyopathy and predisposing to arrhythmias such as ventricular tachycardia, heart failure, and sudden cardiac death

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Risk Factors

• Autosomal dominant gene mutation in desmosome proteins including :
  • DSC2
  • DSG2
  • DSP
  • JUP
  • PKP2
  • TMEM43
• Less common genetic causes include :
  • CTNNA3
  • DES
  • LMNA
  • PLN
  • RYR2
  • TGFB3
  • TTN

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Differential Diagnosis

• Myocarditis
• Sarcoidosis
• Dilated Cardiomyopathy
• Myocardial Infarction
• Brugada Syndrome
• Idiopathic Right Ventricular Outflow tract Tachycardia

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Clinical Features

• History:
  • Some patients are asymptomatic
  • Symptomatic patients complain of of fatigue, palpitations
  • Syncope or cardiac arrest during exercise
• Physical Exam
  • Largely unremarkable

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Evaluation

ARVD with T-wave inversions in the precordial and inferior leads (without RBBB pattern), epsilon wave in V1, localized QRS widening in V1-V2

Right Ventricular Outflow Tract (RVOT) Tachycardia, demonstrated by regular broad complex tachycardia with LBBB morphology, left axis deviation, AV dissociation in V1

Radiographs

• Standard Chest Radiograph
  • Typically normal

EKG

• T wave inversions in V1-V3 are the most common finding (85% of patients)
  • Absence of RBBB
• Epsilon wave is present in 50% of cases
  • Most specific finding
• LBBB morphology can also be seen
  • Ventricular ectopy of LBBB morphology, with frequent PVCs > 1000 per 24 hours
  • Paroxysmal episodes of ventricular tachycardia (VT) with LBBB morphology (RVOT tachycardia)
• Localized QRS widening in V1-3 (> 110ms)
• Prolonged S wave upstroke of 55ms in V1-3

Echocardiography

• May reveal:
  • Enlarged RV
  • Hypokinetic RV
  • Paper thin RV wall

MRI

• Cardiac MRI may reveal:
  • Transmural diffuse bright signal in the RV free wall due to myocardial atrophy with fibrofatty displacement

Diagnostic Criteria

• Diagnosis requires 2 major criteria, 1 major and 2 minor, or 4 minor criteria.
  • Major Criteria :
    • RV dysfunction including severe dilatation with reduced RV ejection fraction with normal LV function
    • Localized RV aneurysms
    • Fibrofatty replacement of myocardium on endomyocardial biopsy
    • Epsilon waves in V1-V3
    • QRS prolongation >110 ms in V1-V3
    • Family history confirmed on autopsy or surgery
  • Minor Criteria :
    • Mild global right ventricle dilatation and/or reduced ejection fraction with normal LV
    • Mild segmental dilatation
    • Regional RV hypokinesis
    • Inverted T waves in V2-V3 in patient >12 years old in the absence of RBBB
    • Late potentials on signal averaged EKG
    • Ventricular tachycardia coupled with LBBB morphology
    • Frequent PVCs
    • Family history of sudden cardiac death <35
    • Family history of ARVD

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Management

Nonoperative

• Pharmacologic:
  • Sotalol is the most effective anti-arrhythmic agent
  • Anticoagulation such as with Warfarin are generally recommended
• Radiofrequency ablation may be used to treat refractory ventricular tachycardia which is traditionally 60-90% successful
  • Recurrence rate is 60% due to progression of disease

Operative

• ICD placement to prevent against sudden cardiac death
• Cardiac transplant is indicated for uncontrolled arrhythmias or failure to manage right ventricular or biventricular failure with pharmacotherapy

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Rehab and Return to Play

Return to Play

• Patients should refrain from rigorous sports
• Can participate in low intensity class 1A sports such as billiards, bowling, riflery, and golf

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Complications and Prognosis

Prognosis

• Longterm prognosis generally favorable
• For patients who qualify with ICD placement, there is higher rate of life threatening and rapid arrhythmias
• Prognosis is closely related to development of heart failure

Complications

• Ventricular Tachycardia
• Sudden Cardiac Death

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