Biology

Diastole

Cardiology

Dilated cardiomyopathy

Hydroxychloroquine

Pulmonary wedge pressure

Coronavirus disease 2019 (COVID-19)

Restrictive cardiomyopathy

Heart failure

Bioinformatics

Blood pressure

Myocardial infarction

Infectious disease (medical specialty)

Internal medicine

Cardiomyopathy

Medicine

Ejection fraction

Transthoracic echocardiogram

Disease

Ventricle

Interventricular septum

Postgraduate Medical Journal

A man in his 60s presented to our clinic for worsening exercise capacity, dyspnoea on exertion for 18 months and chest pain not associated with exercise. He had medical history of rheumatoid arthritis (RA), Sjogren's syndrome, Raynaud's phenomenon, gastro-oesophageal reflux, dyslipidaemia and Parkinson's disease. He was on hydroxychloroquine (HCQ) for RA at the time of presentation. A nuclear stress test was normal. Cardiac angiogram showed left ventricular ejection fraction of 55%, normal coronary arteries, normal systolic pulmonary pressure but elevated left ventricular end-diastolic pressure, right atrial pressure, pulmonary capillary wedge pressure and right ventricular end-diastolic pressure, which were compliant with diastolic dysfunction and possibly infiltrative cardiomyopathy. Two-dimensional (2D) echocardiogram showed left ventricular relaxation abnormality and pulmonary hypertension. Cardiac MRI (CMR) showed thin myocardial wall with basement segment thickness of 0.7 cm, well below average myocardial mass and dilated right ventricle. There was no evidence of myocardial scar, infarction or infiltrative process. Endomyocardial biopsy showed cardiac myocytes with fibre enlargement, fibre size variation, endocardial fibrosis, perivascular fibrosis and vacuoles containing brown pigment, suggestive of lipofuscin raising possibility of HCQ toxicity under light microscopy. Electron microscopy showed clear vacuoles in myocytes with patchy accumulation of glycogen in myocytes and lipofuscin-like material in some vacuolated areas as described in HCQ toxicity (figure 1).

Hydroxychloroquine-induced restrictive cardiomyopathy: a case report