Imaging of cardiac amyloidosis by (99m)Tc-PYP scintigraphy.

Objective: Cardiac amyloidosis (CA) is an underestimated and underdiagnosed cause of cardiac insufficiency. Despite being often considered as a solitary entity attributable to extracellular deposition of fibrillary proteins, there exist at least two different pathophysiologic backgrounds, with different clinical course and treatment. a) In light-chain cardiac amyloidosis (immunoglobulin light-chain amyloidosis-AL) the fibrils consist of light-chain immunoglobulins produced by a clonal plasma cell population in bone marrow.