Occasionally increased ¹⁸F-fluorodeoxyglucose uptake in apical hypertrophic cardiomyopathy with mid-ventricular...

We report on a 77-year-old man who was diagnosed with apical hypertrophic cardiomyopathy (HCM) with mid-ventricular obstruction. He had a cured hepatitis C infection. We detected occasionally increased ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) uptake on whole-body positron emission tomography (PET)/computed tomography (CT) performed to examine the involvement of bladder carcinoma. ¹⁸F-FDG-PET was restudied following specific preparation involving an 18-h low-carbohydrate diet and following 15-h fasting plus heparin pre-administration. Increased uptake of ¹⁸F-FDG was observed reproducibly in the hypertrophic apical to mid left ventricular myocardium, with a maximum standardized uptake value of 6.2. In contrast, relatively lower ¹⁸F-FDG-uptake areas tended to match areas of late gadolinium enhancement on cardiac magnetic resonance (CMR). Histopathological examination of myocardial biopsy showed disarried hypertrophic myocytes with cellular infiltration. Increased uptake of ¹⁸F-FDG may reflect the phenomenon of increased glucose utilization in hypertrophied myocardium. The increasing clinical utility of whole-body PET/CT for evaluating malignancies may increase the detection of occasional abnormal ¹⁸F-FDG uptake in the heart. It is necessary to clarify that ¹⁸F-FDG myocardial PET in combination with CMR may provide a more detailed risk assessment in patients with HCM. <Learning objective: Increased ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) uptake was occasionally found in the apex of the heart on whole-body positron emission tomography performed to evaluate bladder cancer involvement. Increased uptake of ¹⁸F-FDG was observed in the hypertrophic apical to mid left ventricular myocardium, while relatively lower ¹⁸F-FDG-uptake areas tended to match areas of late gadolinium enhancement.>.