Abstract
Background: In low-flow, low-gradient aortic stenosis (LFLG AS), restricted aortic valve opening may represent either fixed valvular obstruction or flow-dependent incomplete leaflet opening due to reduced forward flow. Aortic stenosis (AS) and transthyretin cardiac amyloidosis (ATTR-CM) may coexist, making it difficult to distinguish myocardial disease–driven low-flow physiology from clinically relevant valvular obstruction. Case Presentation: An 88-year-old man presented with decompensated heart failure and paradoxical LFLG AS. Dobutamine stress echocardiography (DSE) failed to restore normal flow, and the calculated aortic valve area remained within the severe range despite stress. Computed tomography showed a low aortic valve calcium score (AVCS) of 313 Agatston units, leaving true-severe versus pseudo-severe AS indeterminate. Further evaluation confirmed wild-type ATTR-CM.