Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVD) is an autosomal dominantly inherited heart-muscle disease caused by mutated desmosomal proteins. The myocardium of the right ventricle is replaced with fibrofatty tissue leading to wall thinning/aneurysm and abnormal electrical impulse. Fibrofatty change can also involve the left ventricle. It affects 1 in 1000-5000 of the population and men more commonly than women. Cardiac arrest due to ventricular fibrillation can occur at any time and sudden death occurs in 0.1-3% of those affected by ARVD. Missed diagnosis is common due to obscure EKG findings and the clinical manifestations presenting in the 2nd-4th decade of life. ARVD should be in the differential for adolescents or young individuals with palpitations, syncope, family history of sudden cardiac death or aborted sudden death. EKG abnormalities are (abbreviated from the Task Force in Diagnosis of ARVD):
- Major Criteria
- Epsilon waves
- Localized prolongation (>110 ms) of the QRS complex in right precordial leads (V1 to V3)
- Minor Criteria
- Inverted T waves in right precordial leads (V2 and V3) in absence of RBBB (in patients >14 yrs of age as this is seen with juvenile Twaves)
- Late potentials (signal-averaged EKG, this is a cardiology diagnosis which can identify small variations in the QRS length).
- Left bundle branch block type ventricular tachycardia on ECG, Holter or exercise testing
- Frequent ventricular extrasystoles on Holter (more than 1,000/24 h)
The work up for suspected ARVD includes history, physical examination, chest xray, ECG, Holter, signal-averaged EKG (identifies the exact length of QRS), stress test, and echocardiography.
Check out Dr Smith’s EKG Blog: http://hqmeded-ecg.blogspot.com/2011/08/young-man-with-syncope-while-riding.html
