Right Ventricle-Dominant Cardiac Sarcoidosis Diagnosed Using a Multimodal Approach

Cardiac sarcoidosis (CS) usually affects the left ventricle and presents with nonspecific features like conduction abnormalities and ventricular arrhythmias. However, right ventricle (RV)-dominant involvement has been increasingly reported, making diagnosis difficult.

A 55-year-old man presented with palpitations. Electrocardiography showed bifascicular block, first-degree atrioventricular block, and epsilon waves. Echocardiography revealed RV dilatation and dysfunction, suggesting arrhythmogenic right ventricular cardiomyopathy. However, computed tomography and fluorodeoxyglucose positron emission tomography revealed mediastinal and hilar lymphadenopathy with cardiac uptake. Myocardial biopsy confirmed epithelioid granulomas, diagnosing sarcoidosis. Prednisolone resolved cardiac inflammation, but ventricular tachycardia progressed, requiring cardioverter-defibrillator implantation.

RV-dominant CS can mimic arrhythmogenic right ventricular cardiomyopathy due to overlapping features. This case demonstrates the importance of multimodal imaging and biopsy for accurate diagnosis and highlights the need for arrhythmia monitoring even after inflammation subsides.

Multimodal assessment is key to differentiating RV-dominant CS from arrhythmogenic right ventricular cardiomyopathy, and early diagnosis with appropriate management is essential for better outcomes.