Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC)
All patients with suspected or confirmed ARVC must be referred immediately to a specialized center with expertise in managing this condition, as this is a life-threatening cardiomyopathy with high risk of sudden cardiac death that requires expert multimodal assessment and long-term management. 1
What is ARVC?
ARVC is a rare inherited cardiomyopathy (prevalence 1:1000-1:5000) characterized by progressive fatty/fibrofatty replacement of right ventricular myocardium, though left ventricular involvement is increasingly recognized 1, 2. It follows autosomal-dominant inheritance with variable penetrance, primarily caused by desmosomal gene mutations (especially PKP2, DSP, DSC2, DSG2, JUP, TMEM43) 1, 3.
When to Suspect ARVC
Suspect ARVC in any patient presenting with:
- Unexplained right ventricular dilation or dysfunction
- Ventricular tachyarrhythmias with left bundle branch block morphology
- Syncope (especially during exercise)
- Characteristic ECG changes: epsilon waves, T-wave inversions in V1-V3
- Family history of syncope, sudden death, or confirmed ARVC
- Young athletes with syncope or cardiac arrest during sports 1
Critical caveat: Up to 40% of ARVC patients have normal ECG at initial presentation, though almost all develop pathological changes within 6 years 1. A normal ECG does not exclude ARVC.
Diagnostic Approach
Mandatory Initial Workup
All suspected ARVC patients require assessment using the 2010 Task Force Criteria (updated from 1994 ESC criteria), which combine multiple parameters 1, 3:
ECG and Holter monitoring (Class I, Level C)
- Look for: epsilon waves, T-wave inversions V1-V3, ventricular arrhythmias
- Annual ambulatory ECG monitoring for ongoing management 3
Echocardiography (Class I, Level B)
- Key findings: increased RV outflow tract dimensions, abnormal RV morphology, RV-FAC ≤17% 1
Cardiac MRI (CMR) (Class I, Level B)
Diagnosis Requires:
- Two major criteria, OR
- One major + two minor criteria, OR
- Four minor criteria 1
Additional Testing
Genetic testing should be performed for:
- Index patients: diagnostic confirmation, prognostication, family screening 3
- Cascade screening in first-degree relatives with pre/post-test counseling (Class I, Level B) 3
- PKP2 is the most common pathogenic variant (>10% of cases) 3
Endomyocardial biopsy:
- Only at experienced centers due to high perforation/tamponade risk 1
- Modest sensitivity (<70%), especially from septal samples 1
- Diagnostic triad: >3% fatty tissue, >40% fibrous tissue, <45% residual myocytes 1
Risk Stratification for Sudden Cardiac Death
High-Risk Features (≥10% annual event rate):
- Aborted sudden cardiac death/ventricular fibrillation
- Sustained ventricular tachycardia
- Severe RV dysfunction (RV-FAC ≤17% or RVEF ≤35%)
- Severe LV dysfunction (LVEF ≤35%) 3
Intermediate-Risk Features (1-10% annual event rate):
- Syncope presumed due to ventricular arrhythmia
- Non-sustained ventricular tachycardia
- Moderate RV dysfunction (RV-FAC 17-24% or RVEF 36-40%)
- Moderate LV dysfunction (LVEF 36-45%) 3
Use the ARVC risk calculator for primary prevention ICD decision-making 2, 3
Treatment Recommendations
Lifestyle Modifications (Mandatory)
All ARVC patients must avoid strenuous or high-intensity sports activities (Class I, Level B) 1, 4. This includes:
- Prohibition from most competitive sports (only low-intensity Class 1A sports may be considered) 4
- Exercise restriction may delay disease progression 5
ICD Therapy
Secondary Prevention (Class I, Level B):
- Mandatory ICD for: cardiac arrest survivors or sustained ventricular tachycardia causing hemodynamic instability 1, 3
Primary Prevention:
- Class IIa recommendation: High-risk patients (≥10% annual event rate) 3
- Class IIb recommendation: Intermediate-risk patients with ≥1 major risk factor after careful risk-benefit discussion 3
- Class III (NOT recommended): ICD solely to permit sports participation due to device complication risks 4
Antiarrhythmic Therapy
Beta-blockers (Class I recommendation):
- First-line for patients with extrasystoles or ventricular tachycardia 2
Additional antiarrhythmics (Class IIa):
- If beta-blockers insufficient: add amiodarone, flecainide, or sotalol 2
- Critical: Antiarrhythmics should NOT replace ICD therapy but may be used in patients refusing/ineligible for devices 1
- Flecainide may be particularly beneficial for PKP2 variant carriers (pending RCT results) 6
Catheter Ablation
Class IIa recommendation for recurrent ventricular tachyarrhythmias despite medical therapy 2
Surveillance Protocol
For all diagnosed ARVC patients:
- Multiparametric assessment (ECG + echocardiography) every 1-2 years (Class I, Level C) 3
- Annual ambulatory ECG monitoring 3
- Serial CMR every 2-5 years depending on severity and clinical course 3
- Immediate evaluation for any substantial symptom changes 3
Family Screening
Cascade genetic testing with counseling for all first-degree relatives when pathogenic/likely pathogenic variant identified (Class I, Level B for adults; Class IIa, Level B for children) 3
Asymptomatic relatives testing negative for family variant can be dismissed from regular screening but educated to return if symptoms develop 3
Common Pitfalls to Avoid
- Do not dismiss ARVC based on normal initial ECG - 40% present with normal ECG 1
- Do not interpret CMR without specialized expertise - high inter-observer variability 1
- Do not perform RV free wall biopsy except at experienced centers - high perforation risk 1
- Do not allow ICD placement solely for sports participation - unacceptable risk-benefit ratio 4
- Do not rely on genetic testing alone - only 30-50% pickup rate of known mutations 1, 3
- Do not use antiarrhythmics or ablation as ICD alternatives in high-risk patients 1