Arrhythmogenic right ventricular dysplasia is an inherited disorder of the heart in which the right ventricular myocardial muscle is progressively replaced by fibrofatty tissue. It is one of the causes of sudden cardiac death in young adults, especially athletes.
Arrhythmogenic right ventricular dysplasia (ARVD) is a cardiac disorder in which the normal myocardium is replaced with fibrofatty tissue. It usually affects the right ventricular myocardium but the involvement of the left ventricle and septum have also been reported. Although it was once considered to be rare, ARVD has an incidence ranging from 6 in 10,000 to 44 per 10,000 in some populations . It has a strong familial association with a majority of patients having an autosomal dominant pattern of inheritance  . ARVD is one of the main causes of sudden cardiac death, accounting for about 4% of deaths in athletes and 5% of sudden cardiac deaths amongst individuals younger than 65 years of age    .
As the disorder is progressive, the clinical presentation may include different symptoms. In most cases, patients with ARVD are young men who present with chest pain or palpitations. Other common manifestations include syncope, atypical chest pain, dyspnea, and sudden cardiac death  . Occasionally symptoms like abdominal pain and confusion may also be present. Rarely, patients can have a cardiac arrest after physical exertion and this may be the first indication of the disorder  .
ARVD workup begins with a detailed personal and family history. A history of palpitations, especially in a young athlete or a family history of sudden cardiac death should raise clinical suspicion of ARVD. On physical examination, the presence of a widely split S2 and a third and fourth heart sound are clues to the diagnosis of ARVD although most patients can have a normal cardiac examination . Invasive and non-invasive cardiac testing are essential to confirm the diagnosis. These include electrocardiogram (ECG), Holter monitoring, exercise stress test, right ventricular angiography, contrast echocardiography, electrophysiologic studies, and endomyocardial biopsy.
An ECG performed at rest has typical findings such as inverted T-wave in V1 through V6 leads, small deflections immediately following the QRS complex called epsilon waves in leads V1 through V3, and left bundle branch or even right bundle branch block patterns   . Holter monitoring and exercise stress test are normal in a majority of cases although stress test can induce ventricular tachycardia in advanced cases of ARVD . Electrophysiology helps to detect tachycardia events, their role in the development of serious arrhythmias, and to differentiate between idiopathic right ventricular arrhythmias and ARVD   .
Choosing an imaging modality for the diagnosis of ARVD is difficult . Contrast echocardiography and right ventricular angiography are invasive but help to identify aneurysms and dyskinetic areas of the ventricular wall while cardiac magnetic resonance imaging (MRI), provides, noninvasively, the location of myocardial changes and dysfunction but cannot readily identify intramyocardial fibrofatty transformation      .
The gold standard test for diagnosis of ARVD is endomyocardial biopsy as it has a high specificity. However, it has a low sensitivity since the biopsy has to be taken from the ventricular septum, which has a low risk of perforation but this region also has a minimal activity of the disease .