99m Tc-PYP and 99m Tc-MDP Scintigraphy in a Rare Case of Combined ApoA-I Cardiac Amyloidosis and Paget Disease of the Bone.

A 70-year-old man with a 20-year history of heart failure developed atrial fibrillation and underwent pacemaker implantation; however, his heart failure continued to worsen. Imaging with 99m Tc-PYP scintigraphy revealed significant uptake in the myocardium and the right pelvic bone. Similarly, 99m Tc-methylene diphosphonate scintigraphy demonstrated positive uptake in both regions. A myocardial biopsy confirmed cardiac amyloidosis, and mass spectrometry identified ApoA-I amyloidosis. In addition, a bone biopsy of the right iliac wing resulted in a pathologic diagnosis of Paget disease of bone.