CARDIAC SARCOIDOSIS MIMICKING HYPERTROPHIC CARDIOMYOPATHY - CLINICAL UTILITY OF RADIONUCLIDE IMAGING FOR DIFFERENTIAL-DIAGNOSIS

A 62-year-old woman with skin sarcoidosis was admitted to our hospital to ascertain whether she had cardiac involvement. Although she displa yed no cardiac signs or symptoms, the electrocardiogram showed first-d egree atrioventricular block, right bundle branch block with left ante rior fascicular block, and giant negative T waves in the V-3 lead. Ech ocardiography revealed marked hypertrophy localized in the basal porti on of the interventricular septum (IVS) without systolic dysfunction, mimicking hypertrophic cardiomyopathy (HCM). Exercise thallium-201 myo cardial imaging revealed redistribution in the anteroseptal region. Bo th gallium-67 (Ga-67) and technetium-99m pyrophosphate (Tc-99m-PYP) sc intigraphy revealed abnormal uptake in the myocardium. These findings disappeared after 2 months of steroid treatment. Reports of cardiac sa rcoidosis mimicking HCM are rare, However, hypertrophy in the basal po rtion of the IVS is an important sign of early cardiac involvement in sarcoidosis. Ga-67 and Tc-99m-PYP scintigraphy were useful and necessa ry to differentiate this type of cardiac sarcoidosis from HCM.