Atypical Dilated and Nonhypertrophic Cardiac Transthyretin Amyloidosis: Concept of Overlapping Cardiomyopathies.

• Subtle age-related ATTR-CM can complicate preexisting other HF etiologies. • Combined cardiomyopathies can present with atypical clinical/imaging presentation. • Multimodal imaging assessment is required in overlapping cardiomyopathies. • Absence of myocardial thickening should not rule out an infiltrative disorder. • Endomyocardial biopsy remains important in the context of equivocal imaging.