Cardiac AL amyloidosis with multisystem manifestations: Case report and brief literature review

Systemic light-chain (AL) amyloidosis is a rare but lethal plasma cell disorder characterized by amyloid deposition from misfolded immunoglobulin light chains, often leading to multi-organ dysfunction. Cardiac involvement is the predominant driver of prognosis and survival.

A 66-year-old man presented with an eight-month history of progressive exertional dyspnea, fatigue, and bilateral leg edema. His past medical history included controlled hypertension and diabetes mellitus. Physical examination revealed signs of advanced heart failure, including elevated jugular venous pressure (12 cm H₂O), bibasilar crackles, peripheral edema, and neuropathy. Electrocardiography showed low-voltage QRS complexes in the limb leads, and echocardiography demonstrated concentric left ventricular hypertrophy (septal thickness 16 mm) with preserved systolic function. Strain imaging displayed an apical-sparing “cherry-on-top” pattern, and cardiac MRI revealed markedly increased extracellular volume, suggesting amyloid infiltration. 

Endomyocardial biopsy confirmed amyloid deposition, exhibiting Congo red positivity with apple-green birefringence and lambda light chain restriction. The patient was diagnosed with systemic AL amyloidosis and advanced cardiac involvement. He was treated with bortezomib, cyclophosphamide, and dexamethasone, and later escalated to daratumumab due to limited hematologic response. Despite aggressive therapy, he developed refractory heart failure and died 29 months after diagnosis.

This case highlights the subtle early signs of cardiac amyloidosis and underscores the critical importance of recognizing and treating it promptly before irreversible organ damage develops.