Chloroquine-induced cardiomyopathy: a reversible cause of heart failure

Abstract

Chloroquine (CQ) and hydroxychloroquine (HCQ) are anti-rheumatic medications frequently used in the treatment of connective tissue disorders. We present the case of a 45-year-old woman with CQ-induced cardiomyopathy leading to severe heart failure. Electrocardiographic abnormalities included bifascicular block, while structural disease consisted of severe biventricular and biatrial hypertrophy. Appropriate diagnosis via endomyocardial biopsy led to cessation of CQ and subsequent dramatic improvement in symptoms and structural heart disease. Cardiac toxicity is an under-recognized adverse effect of CQ/HCQ leading to cardiomyopathy with concentric hypertrophy and conduction abnormalities, with the potential for significant morbidity and mortality. Predisposing factors for CQ/HCQ-induced cardiomyopathy have been proposed. CQ/HCQ cardiomyopathy is a phenocopy of Fabry disease, and α-galactosidase A polymorphism may account for some heterogeneity of disease presentation.

Keywords: Cardiac MRI; Cardiomyopathy; Chloroquine; Heart failure.

Figure 1

Electrocardiogram on initial admission demonstrating conduction abnormalities (bifascicular block) with signs of biventricular hypertrophy.

Figure 2

Cardiac magnetic resonance imaging prior to discontinuation of chloroquine (A), with biventricular hypertrophy and biatrial dilatation shown on two‐chamber (A1), three‐chamber (A2), four‐chamber (A3), and short‐axis (A4) views. Cardiac magnetic resonance imaging was performed after cessation of chloroquine (B), demonstrating significant resolution of structural abnormalities shown on two‐chamber (B1), three‐chamber (B2), four‐chamber (B3), and short‐axis (B4) views.

Figure 3

Pathology images of endomyocardial biopsy specimen. Light microscopy using haematoxylin and eosin stain demonstrates vacuolization of cardiomyocytes at ×200 magnification (A); light microscopy using periodic acid–Schiff stain at ×400 magnification shows that the vacuoles are periodic acid–Schiff‐negative (B); electron microscopy at ×25 500 magnification demonstrates myeloid and curvilinear myeloid bodies, as well as vacuolated cytoplasm characteristic of chloroquine‐associated cardiomyocyte damage (C).