This record contains raw data related to the article "Differentiating Hereditary Arrhythmogenic Right Ventricular Cardiomyopathy from Cardiac Sarcoidosis Fulfilling 2010 ARVC Task Force Criteria." Abstract Background: The clinical presentation of cardiac sarcoidosis (CS) may resemble that of arrhythmogenic right ventricular cardiomyopathy (ARVC). Objective: The purpose of this study was to identify clinical variables to better discriminate between patients with genetically determined ARVC and those with CS fulfilling definite 2010 ARVC Task Force Criteria (TFC). Methods: In this multicenter study, 10 patients with CS fulfilling definite 2010 ARVC TFC were age and gender matched with 10 genetically proven ARVC patients. A cardiac 18F-fluorodeoxyglucose positron emission tomographic (18F-FDG PET) scan was required for patients to be included in the study. Results: The 2010 ARVC TFC did not reliably differentiate between the 2 diseases. CS patients presented with longer PR intervals, advanced atrioventricular block (AVB), and longer QRS duration (P <.001 and P = .009, respectively), whereas T-wave inversions (TWIs) in the peripheral leads were more common in ARVC patients (P = .009). CS patients presented with more extensive left ventricular involvement and lower left ventricular ejection fraction (LVEF), whereas ARVC patients had a larger right ventricular outflow tract (RVOT) (P = .044). PET scan positivity was only present in CS patients (90% vs 0%). Conclusion: The 2010 ARVC TFC do not reliably differentiate between CS patients fulfilling 2010 ARVC TFC and those with hereditary ARVC. Prolonged PR interval, advanced AVB, longer QRS duration, right ventricular apical involvement, reduced LVEF, and positive 18F-FDG PET scan should raise the suspicion of CS, whereas larger RVOT dimensions, subtricuspid involvement and peripheral TWI favor a diagnosis of hereditary ARVC.