Popeye Sign in Transthyretin Amyloidosis

To the Editor: Kurisu and Fujiwara (Sept. 4 issue) 1 report on a patient in whom wild-type transthyretin amyloidosis (ATTR) was diagnosed after histopathological analysis of an endomyocardial-biopsy sample revealed amyloid deposits. It was unnecessary to perform this high-risk procedure because a noninvasive diagnosis could have been made. The patient presented with biceps tendon rupture, heart failure with preserved ejection fraction, low-voltage QRS complexes, a thickened left ventricular wall on echocardiography, grade 3 myocardial uptake of the radiotracer on technetium-99m–labeled pyrophosphate scintigraphy, and no monoclonal gammopathy detected on serum or urine tests. Taken together, the diagnostic algorithm for ATTR with cardiomyopathy . . .