|Year : 2015 | Volume
| Issue : 2 | Page : 142-144
Arrhythmogenic right ventricular cardiomyopathy
Parveen Bhardwaj1, Minoo Sharma2, Neeraj Ganju3
1 Department of Pediatrics, Indira Gandhi Medical College, Shimla, Himachal Pradesh, India
2 Department of Physiology, Indira Gandhi Medical College, Shimla, Himachal Pradesh, India
3 Department of Cardiology, Indira Gandhi Medical College, Shimla, Himachal Pradesh, India
|Date of Web Publication||30-Jul-2015|
Department of Pediatrics, Indira Gandhi Medical College, Shimla - 171 001, Himachal Pradesh
Source of Support: None, Conflict of Interest: None
Arrhythmogenic right ventricular cardiomyopathy (ARVC) also called as arrhythmogenic right ventricular dysplasia (ARVD) is an inherited heart muscle disease that predominantly affects the right ventricle (RV). The main pathologic feature is the progressive loss of RV myocardium and its replacement by fibrofatty tissue. Clinical manifestations develop most often between the second and third decades of life and are related to ventricular tachycardia (VT) or ventricular fibrillation (VF), which may lead to sudden death in young people.
Keywords: Arrhythmogenic right ventricular cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, premature ventricular complexe
|How to cite this article:|
Bhardwaj P, Sharma M, Ganju N. Arrhythmogenic right ventricular cardiomyopathy. Nig J Cardiol 2015;12:142-4
| Introduction|| |
Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited heart disease. It is caused by genetic defects of the parts of heart muscle known as desmosomes, important for linking myocytes together. It is characterized with fibrofatty replacement of the right ventricular myocardium, with associated arrhythmias originating in the right ventricle (RV). ARVC is an important cause of ventricular arrhythmias and sudden cardiac death in children and young adults.
| Case report|| |
A 17-year-old male adolescent presented to us with history of progressive breathlessness over a period of 2 months with fatigue and effort intolerance. History of progressive swelling starting from feet was also present and there was history of dizziness and syncope since last one month. No history of such disease or sudden death was present in the family members. On examination, heart rate was 66/min with irregular low volume pulse, JVP was raised, Pedal edema was present and BP was 106/70 mm Hg. Heart sounds were muffled with a pan-systolic murmur in the tricuspid area; chest X-ray revealed cardiomegaly with cardiothoracic ratio of 70%. EKG showed T wave inversion in V1, V2, V3 leads and multiple premature ventricular contractions [Figure 1]. Echocardiography [Figure 2]a and b revealed dilated right atrium and ventricle with low pressure tricuspid regurgitation with severe right ventricular systolic dysfunction, right ventricle outflow tract (RVOT) was dilated and mild left ventricular systolic dysfunction with left ventricular clot. Cardiac MRI revealed dilated RV and right atrium and clot in left ventricle. Clinical possibility of ARVC was found relevant, and the child was started on tab furosemide, spironolactone, enalapril, and warfarin. After treatment, his breathlessness improved and edema subsided and his effort tolerance increased. The child is under regular follow up and is better.
|Figure 1: ECG-Changes: T wave inversion in right sided chest leads and multiple. PVC - Premature ventricular contractions|
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|Figure 2: (a) Four chamber view showing dilated right ventricle (RV) and left ventricular (LV) clot. (b) Para sternal short axis view showing dilated right ventricular outflow tract (RVOT) RA - Right atrium; LA - Left atrium; PA - Pulmonary artery|
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| Discussion|| |
The estimated prevalence of ARVC in the general population ranges from 1 in 2,000 to 1 in 5,000.  ARVC is an important cause of ventricular arrhythmias in children and young adults. Studies have shown that ARVC is present in up to 20% of individuals who experience sudden cardiac death (SCD) and is even more common among athletes who die suddenly.  It is seen predominantly in males.
ARVC is an autosomal dominant trait with reduced penetrance. Approximately 40-50% of ARVC patients have a mutation identified in one of several genes encoding components of the desmosome, which can help confirm a diagnosis of ARVC. ,
Pathological ARVC is characterized by fatty infiltration and fibrofatty infiltration. Initially, fatty infiltration is confined to the RV. This involves a partial or near-complete substitution of myocardium with fatty tissue without wall thinning. It involves predominantly the apical and infundibular regions of the RV. The left ventricle and ventricular septum are usually spared. No inflammatory infiltrates are seen in fatty infiltration. There is evidence of myocyte degeneration, seen in 50% of cases of fatty infiltration. 
Many people with ARVC do not have any symptoms; individuals with ARVC remain asymptomatic for a long time. Many individuals have symptoms associated with ventricular tachycardia (VT), such as palpitations, light-headedness, or syncope. Usually these symptoms are exercise related. Others may have symptoms and signs related to right ventricular failure, such as raised jugular venous pressure, lower extremity edema, or liver congestion with elevated hepatic enzymes. Eventually, the left ventricle will also become involved, leading to bi-ventricular failure. In later stages, signs and symptoms of left ventricular failure may become evident, including congestive heart failure, atrial fibrillation, and an increased incidence of thromboembolic events. Unfortunately, sudden death may be the first manifestation of disease.
There is no pathognomonic feature of ARVC. The diagnosis of ARVC is based on meeting a set of specific criteria devised by task force of the working group myocardial and pericardial disease of the European society of cardiology and of the Scientific Council on Cardiomyopathies of the International Society and Federation of Cardiology in 1994 and subsequently revised in 2010. , These criteria take into account, echocardiography, ECG abnormalities, arrhythmias, structural abnormalities, tissue characteristics, as well as family history and genetics.
Total 90% of individuals with ARVC have some EKG abnormality. The most common EKG abnormality seen in ARVC is T wave inversion in leads V 1 to V 3 in the absence of right bundle branch block (RBBB) as in our case. The epsilon wave described as a terminal notch in the QRS complex is found in about 50% of those with ARVC. This is due to slowed intraventricular conduction. The type of arrhythmia ranges from frequent premature ventricular complexes (PVCs) to VT to ventricular fibrillation (VF). 
Echocardiography may reveal an enlarged, hypokinetic RV with a paper-thin RV free wall. The dilatation of the RV will cause dilatation of the tricuspid valve annulus, with subsequent tricuspid regurgitation. Paradoxical septal motion may also be present.
Fatty infiltration of the RV free wall can be visible on cardiac MRI. Fat has increased intensity in T1-weighted images. Cardiac MRI can visualize the extreme thinning and akinesis of the RV free wall. 
Right ventricular angiography may reveal an akinetic or dyskinetic bulging localized to the infundibular, apical, and subtricuspid regions of the RV. Transvenous endocardial biopsy of the RV can be highly specific for ARVC, but it has low sensitivity. False negatives are common because the disease progresses typically from the epicardium to the endocardium (with the biopsy sample coming from the endocardium), and the segmental nature of the disease. 
The goal of management of ARVC is to decrease the incidence of SCD. Management options include pharmacological management of arrhythmia suppression, control of congestive cardiac failure, and prevention of thrombus formation. Catheter ablation may be used to treat intractable VT. If the arrhythmias associated with the disease are uncontrollable or if there is severe bi-ventricular heart failure that is not manageable with pharmacological therapy, cardiac transplant is indicated.
All first-degree family members of the affected individual, and young adults involved in competitive sport should be screened for ARVC so that it can be identified in presmyptomatic stage and proper management can be started early.
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[Figure 1], [Figure 2]