Hot Hearts on Bone Scintigraphy Are Not All Amyloidosis

A 54-year-old woman with a history of end-stage renal disease was found to have infiltrative cardiomyopathy by echocardiography. 99m Tc-pyrophosphate ( 99m Tc-PYP) scintigraphy was positive with a remarkable myocardial uptake. Gene test found a mutation of AGXT , confirming a final diagnosis of primary hyperoxaluria. Radiotracer uptake was due to high myocardial oxalate deposition. This case illustrates false positivity of the 99m Tc-PYP scan caused by hyperoxaluria-associated cardiomyopathy, which raises awareness for other conditions apart from amyloid cardiomyopathy.