Arrhythmogenic right ventricular cardiomyopathy resident survival guide

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Steven Bellm, M.D. [2]

Arrhythmogenic right ventricular cardiomyopathy resident survival guide Microchapters
Overview
Classification
Causes
FIRE
Diagnosis
Treatment

Overview

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a genetic disease characterized by myocyte loss and fibro-fatty tissue replacement of the right ventricular myocardium. This puts patients into risk of life-threatening ventricular arrhythmias and slowly progressive ventricular dysfunction. The diagnostic is challenging. Diagnosis of ARVC relays on a scoring system, with major or minor criteria on the Revised Task Force Criteria. Pharmacologic treatment of arrhythmias, catheter ablation of ventricular tachycardia, and ICD are main goals of the treatment.

Classification

Stages of disease

• Concealed phase: Subclinical asymptomatic phase
• Overt electrical disorder: Palpitations, syncope and typically with symptomatic ventricular arrhythmias of RV
• RV failure: Progressive loss of RV myocardium due to fibro-fatty replacement impairs RV function, pump failure
• Biventricular failure: Involvement of the interventricular septum and LV causing congestive heart failure (HF)

Patterns of expression

• Classic ARVC:Increased RV to LV volume ratio, more severe involvement of the RV, negative anterior T waves and ventricular arrhythmias with LBBB morphology
• Left-dominant arrhythmogenic cardiomyopathy (LDAC):Predominantly involves the LV, LV wall motion abnormalities, chamber dilation, systolic impairment, and late gadolinium enhancement (LGE), ventricular arrhythmias of right bundle branch block (RBBB) morphology, (infero)-lateral T-wave inversion
• Biventricular arrhythmogenic:Early and parallel involvement of the RV and LV, biventricular dilation and systolic impairment, ventricular arrhythmias of both RBBB and LBBB configuration may occur, ratio of RV to LV volume remains close to 1

Causes

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a genetic disease.

FIRE: Focused Initial Rapid Evaluation

A Focused Initial Rapid Evaluation (FIRE) should be performed to identify patients in need of immediate intervention. The diagnosis of ARVC is currently based on the presence of major and minor standardised Task Force Criteria. Diagnosis is established when two major, one major plus two minor, or four minor criteria from different groups are fulfilled.

❑  Global and/or regional dysfunction and structural alterations:
Major

❑  Severe dilatation and reduction of right ventricular ejection fraction with no (or only mild) left ventricular impairment

❑  Localised right ventricular aneurysms (akinetic or dyskinetic areas with diastolic bulging)

❑  Severe segmental dilatation of the right ventricle

Minor

❑  Mild global right ventricular dilatation and/or ejection fraction reduction with normal left ventricle

❑  Mild segmental dilatation of the right ventricle

❑  Regional right ventricular hypokinesia

❑  Tissue characterisation of wall
Major

❑  Fibrofatty replacement of myocardium on endomyocardial biopsy

❑  Repolarisation abnormalities
Minor

❑  Inverted T waves in right precordial leads (V2 and V3) (people aged >12 years, in absence of right bundle branch block)

❑  Depolarisation/conduction abnormalities
Major

❑  Epsilon waves or localised prolongation (>110 ms) of the QRS complex in right precordial leads (V1–V3)

Minor

❑  Late potentials (signal-averaged ECG)

❑  Arrhythmias
Major

❑  Arrhythmias listed below plus T-wave abnormalities—see III Repolarisation abnormalities

Minor

❑  Left bundle branch block type ventricular tachycardia (sustained and nonsustained) (ECG, Holter, exercise testing)

❑  Frequent ventricular extrasystoles (>1000/24-h) (Holter)

❑  Family history
Major

❑  Familial disease confirmed at necropsy or surgery

Minor

❑  Family history of premature sudden death (<35 years) due to suspected ARVC

❑  Family history of ARVC (clinical diagnosis based on present criteria)

Complete Diagnostic Approach

A complete diagnostic approach should be carried out after a focused initial rapid evaluation is conducted and following initiation of any urgent intervention.

History and symptoms: ❑  Hints for etiology (family history) ❑  Duration and onset of illness/ symptoms ❑  Severity and triggers of dyspnea/ orthopnea and fatigue/ weakness, presence of chest pain, exercise capacity, physical activity, sexual activity (NYHA?) ❑  Palpitations/ (pre)syncope/ ventricular tachycardias/ cardiac arrest or fibrillation ❑  Weight loss/weight gain (cachexia/ volume overload?) ❑  Symptoms of transient ischemic attack or thromboembolism (anticoagulation necessary?) ❑  Presence of peripheral edema, ascites or anasarca (volume overload?) ❑  Problems with breathing at night/ sleep ❑  Medical history ❑  Prior hospitalizations ❑  Medication ❑  Diet (restriction of sodium and fluid intake?)

Physical examination: ❑  Vital signs: ❑  Pulse (strength and regularity) ❑  Blood pressure ❑  Respiratory rate ❑  General appearance: ❑  BMI(weight loss/weight gain) ❑  Peripheral edema ❑  JVD ❑  Heart: ❑  Heart sounds, murmur, Carotid and peripheral pulses ❑  Lungs: ❑  Rales? ❑  Pleural effusion? ❑  Hepatomegaly, pulsatile liver and/or ascites (volume overload) ❑  Extremities: ❑  Temperature of lower extremities, edemas

Laboratory findings: ❑  Complete blood count ❑  Chemistry: ❑  Troponin, BNP or NT-proBNP ❑  Serum electrolytes (including calcium and magnesium) ❑  Blood urea nitrogen ❑  Serum creatinine ❑  Glucose ❑  Fasting lipid profile ❑  Liver function tests ❑  Thyroid-stimulating hormone

Imaging and additional tests: ❑  Noninvasive imaging and tests: ❑  12-lead ECG: ❑  Ventricular tachycardia (VT) of left bundle branch block morphology ❑  T wave inversion in V1–V3 ❑  Premature ventricular complexes of left bundle branch block morphology ❑  Epsilon waves or localised prolongation (>110 ms) of the QRS complex in right precordial leads (V1–V3) ❑  24-hour ambulatory ECG/ signal-averaged ECG ❑  Late potentials ❑  Frequent ventricular extrasystoles (>1000/24-h) ❑  Stress test ❑  Chest x-ray: ❑  2D echocardiography with Doppler: ❑  Dilatation and reduction of right ventricular ejection fraction with no (or only mild) left ventricular impairment ❑  Localised right ventricular aneurysms ❑  Segmental dilatation of the right ventricle ❑  Contrast-enhanced cardiac magnetic resonance (MRI): If diagnosis is not clear by other methods ❑  Invasive imaging and tests: ❑  Contrast angiography If diagnosis is not clear by other methods ❑  Endomyocardial biopsy: If diagnosis is not clear by other methods ❑  Fibrofatty replacement of myocardium

Treatment

❑  Prevention of sudden death:

❑  Risk assessment:Cardiac arrest, syncope, young age, malignant family history, participation in competitive sports, VT, severe right ventricular dysfunction, Left ventricular involvement, and QRS dispersion of 40 ms or more

❑  Asymptomatic patients or healthy gene carriers: Check of medical history, basal 12-lead ECG, 24-h Holter monitoring, exercise testing, and echocardiography on a regular basis

❑  Patients with haemodynamically stable arrhythmias: Beta blockers or/and class III antiarrhythmic drugs (sotalol and amiodarone), use assessed by electrophysiologic testing

❑  Patients with cardiac arrest, syncope, or haemodynamically poorly-tolerated VT despite antiarrhythmic therapy:Treatment with ICD

❑  Patient with early and severe right ventricular dysfunction or advanced disease with biventricular involvement: Consider prophylactic ICD implantation

❑  Patients with heart failure: Diuretics, angiotensin-converting-enzyme inhibitors and digitalis, and anticoagulants

❑  Patients with refractory congestive heart failure or untreatable ventricular arrhythmias:Heart transplantation as final therapeutic

❑  Restriction of physical exercise for all patients