PO-04-087 NOT ALL THAT SHINES IS GOLD AND NOT EVERY LIGHT UP ON PET SCAN IS CARDIAC SARCOIDOSIS

Abstract

Cardiac sarcoidosis (CS) and arrhythmogenic right ventricular cardiomyopathy (ARVC) are rare conditions with different pathogenesis but often similar clinical and imaging findings. Therefore differential diagnosis could be challenging. We present a case of ARVC of insidious onset mimicking CS. N/A Our patient is a 51 year-old male with no cardiac history who presented to the emergency room (ER ) with frequent chest pain. Three years ago, work up resulted in negative coronary angiogram and cardiac MRI that showed focal myocardial inflammation so he was diagnosed with myocarditis. This time, he presented to the ER with chest pain and wide complex tachycardia [figure A]. Treatment with metoprolol terminated ventricular tachycardia. Echocardiography revealed normal biventricular function with mild right ventricular (RV) enlargement. The patient underwent PET myocardial perfusion scan that showed focal FDG uptake in the basal septal and inferolateral segments suspicious for sarcoidosis [figure B,C (FDG uptake - blue arrows)]. Repeated CMR demonstrated dilated RV with regional akinesis of the free wall and late gadolinium enhancement (LGE) of RV wall [figure D,E (LGE in right venticle wall-yellow arrows)]. No LGE in the left ventricle was noted. These CMR findings were consistent with ARVC. Due to the discrepancy in the results of both imaging modalities, genetic testing was utilized for further help with the diagnosis. Results were positive for PKP2 gene mutation which is highly suggestive of ARVC. Patient continued beta-blockers and was scheduled to have a defibrillator and genetic counselling. Although CS should be considered in every ARVC like presentation, the final diagnosis should not be built on PET scan results only. Genetic testing, tissue biopsy and even repeat cardiac MRI over the course of the disease are major pillars in such critical diagnosis.