Hydroxychloroquine Cardiotoxicity Mimicking Transthyretin Cardiac Amyloidosis in a Patient With HFpEF

Background

Hydroxychloroquine (HCQ) is an immunomodulatory drug used in systemic lupus erythematosus and other rheumatologic disorders, with rare but potentially severe cardiotoxic effects. Case summary: A 77-year-old woman with a history of systemic lupus erythematosus and heart failure with preserved ejection fraction presented with subacute worsening chest pain, dyspnea, palpitations, and neuropathy. Electrocardiogram showed low voltage; echocardiogram revealed moderate concentric left ventricular hypertrophy with reduced global longitudinal strain without apical sparing. Coronary angiography was normal. Technetium-99m pyrophosphate scintigraphy showed focal grade 2 uptake. Endomyocardial biopsy revealed widespread myocyte hypertrophy and lysosomal curvilinear bodies consistent with HCQ cardiotoxicity.

Discussion