Hydroxychloroquine-induced cardiomyopathy: a novel case highlighting the role of electron microscopy in diagnosis

Hydroxychloroquine-induced cardiomyopathy is a rare adverse reaction with serious and potentially fatal outcomes. We report 56-year-old female who presented in acute right heart failure NYHA class III symptoms, ascites, raised JVP pressure, peripheral oedema. Significant medical history included SLE (diagnosed her late 20s, well controlled on hydroxychloroquine), CKD, poorly hypertension. Extensive investigations transthoracic ECHO, cardiac MRI, amyloidosis scan, catheter. Left ventricular hypertrophy, pulmonary hypertension, severe restrictive cardiomyopathy, preserved ejection fraction (LVEF 66%) were determined. There no features of infiltrative including amyloidosis, Fabry screening was negative. Due to uncertain aetiology the patient underwent biopsy. Light microscopy revealed myocyte disarray glycogen vacuolation inflammation. Amyloid not identified. Electron extensive myeloid figures occasional curvilinear bodies within myocytes, confirming hydroxychloroquine-induced cardiomyopathy. After cessation drug, made significant recovery reduction I symptoms. This case adds body literature regarding this drug highlights importance electron diagnosis.