There is emerging evidence linking cyanotic heart disease and pheochromocytoma-paraganglioma through a proposed hypoxia pathway. We present a 59-year-old woman with known Eisenmenger syndrome secondary to delayed diagnosis of ventricular septal defect, in whom 18F-FDG PET/CT provided comprehensive evaluation of both an 18F-FDG-avid left glomus vagale paraganglioma and also increased right ventricular myocardial glucose metabolism in response to severe pulmonary hypertension in the chronic shunting state.