Transition From Left Ventricular Hypertrophy to Massive Fibrosis in the Cardiac Variant of Fabry Disease

Abstract

A 43-year-old male patient with cardiac Fabry disease was followed up by single-photon emission computed tomography (SPECT) and 18F-deoxyglucose (FDG) positron emission tomography (PET) examinations from 1992 onward. At first, he was thought to have concentric left ventricular (LV) hypertrophy, as determined by echocardiography (LV apex wall thickness, 21 mm; diastolic interventricular septum wall thickness, 25 mm; diastolic LV posterior wall thickness, 29 mm; ejection fraction, 76%); however, a diagnosis of cardiac Fabry disease was defined by endomyocardial biopsy and decreased α-galactosidase A activity of the peripheral lymphocyte in 1996. Extracardiac signs of Fabry disease were not detected at that time. In 1992, a PET study after overnight fasting showed increased uptakes of FDG at the apical and lateral walls, whereas PET scanning after oral glucose loading showed a mildly reduced uptake of FDG. The uptakes of FDG were reduced in the apical and lateral walls of the LV on glucose loading images (Figure 1A, lower panel), whereas the uptakes of FDG were increased in the same regions on the fasting images (Figure 1A, upper panel). This mirror-image pattern of uptakes suggested myocardial ischemia at the apical and lateral walls. In 1996, SPECT and PET studies showed …