A rash with a heavy heart.

Cardiac amyloidosis (CA) is relatively rare and frequently misdiagnosed. Other disorders presenting with increased left ventricular (LV) mass can mimic its diagnosis. This case illustrates unique findings of primary light chain (AL) amyloidosis in a patient with remarkable signs of CA. Here, we report a 49-year-old man with prior diagnosis of hypertrophy cardiomyopathy (HCM) based on an echocardiogram performed 1 year earlier that presented with 8 weeks of periorbital rash. He had numbness in the past 3 years. More recently, he presented with shortness of breath. Physical examination was remarkable for periorbital purpura, macroglossia, and orthostatic hypotension. Cardiac auscultation showed S3 and S4. Electrocardiography (ECG) showed diffuse low-voltage QRS complexes. Echocardiography revealed severe diastolic impairment; granular "sparkling" pattern of the myocardium with thickened walls, interatrial septum, and valves; and pericardial effusion. Diastolic dysfunction and thick walls with low ECG voltage are compelling diagnostic findings. Laboratory work up showed increased free light chain-differential (FLC-diff), N-terminal fragment of brain natriuretic peptide (NT-BNP), and cardiac Troponin T (cTnT). Bone marrow biopsy confirmed AL amyloidosis. A diagnosis of AL amyloidosis with cardiac involvement mimicking HCM was made. The patient died during hospitalization due to sudden cardiac death. This cases illustrates the importance of the combination of clinical, serological, electro- and echocardiographic findings to establish the diagnosis of CA.