Abstract 17160: Cardiac Sarcoidosis Mimicking Arrhythmogenic Right Ventricular Cardiomyopathy Presenting With Syncope

A 35-year-old previous healthy man presented with palpitations and nearly syncope. Electrocardiography showed first degree atrioventricular block (PR interval 316 milliseconds) and premature ventricular complex (PVC) possibly originating from right ventricle (RV). The transthoracic echocardiography disclosed dilated RV with preserved right ventricular systolic function with a RV systolic pressure of 33mmHg, and thickened interventricular septum (12.7mm) with normal left ventricular size and function. At this point, the initial diagnosis was arrhythmogenic right ventricular cardiomyopathy (ARVC) with ventricular arrhythmias. The 24-hour Holter study showed 904 monomorphic PVCs and short-run ventricular tachycardia. The chest computed tomography demonstrated dilated RV with scalloping over free wall and multiple lung nodules mainly located in both upper lung fields (Figure A&B). Radiofrequency catheter ablation and implantation of implantable cardioverter defibrillator were suggested under the impression of ARVC. Therefore, he visited our hospital for second opinion. Since the diseased conduction system was unusual in patient with ARVC, CMR imaging was performed which revealed late gadolinium enhancement over both ventricles and basal interventricular septum (Figure C), raising the suspicion of cardiac sarcoidosis. Thereafter, the 18F-fluorodeoxyglucose (FDG)-Positron Emission Tomography study was arranged and showed FDG uptake over basal septum and lateral wall of LV, and multiple lung nodules (Figure D). Endomyocardial biopsy of RV showed myocardial fibrosis without a specific diagnosis. Thoracoscopic wedge resection of the lung nodule was performed, and pathology showed non-necrotizing granulomas distributed along with broncho-vascular bundles and subpleural area. No microorganism could be demonstrated. Sarcoidosis with cardiac and pulmonary involvement was impressed. Further steroid treatment will be initiated.