Background:
ARVC is a rare inherited disorder usually affecting the right ventricle, characterized by fibro-fatty tissue substitution of healthy ventricular myocardium. It often predisposes young patients to ventricular tachycardia, heart failure, and sudden cardiac death. However, due to multiple disease variants, it can involve both ventricles or predominantly the left ventricle with atypical manifestations. Recent post-mortem studies of patients with Arrhythmogenic Cardiomyopathy (ACM) suggest left ventricular involvement in up to 87% of patients.1 Abnormal ECG findings and ventricular arrhythmias may often precede abnormal imaging or structural findings. To date fifteen genes have been identified to cause ARVC with a subset encoding for desmosomal proteins including Plakoglobin (JUP). 2 Phenotypic expression is highly variable, but some evidence suggests young athletic males tend to have a more malignant disease course in part due to their level of hormonal and or physical activity, which in turn contributes a greater degree of mechanical cardiac stress.3
We present a case of a 21-year-old male with a genetically proven family history of ARVC who presented to the hospital with near syncope and through extensive workup, had no evidence of ARVC on initial imaging (echo and CMR). Subsequently, he was found to have multiple episodes of ventricular ectopy and tachycardia. During his second hospitalization, work-up demonstrated atypical, predominantly left ventricular dysfunction on echocardiogram with evidence of new, leftventricular fibrosis on repeat CMR study. A third CMR scan showed interval improvement in myocardial fibrosis once exercise was limited.