Hydroxychloroquine-induced cardiomyopathy that presented as pulmonary hypertension: a newly noted complication.

We examined a 63-year-old woman with progressive dyspnea. Two years prior to admission to our hospital, she had been diagnosed with rheumatoid arthritis and treated with hydroxychloroquine (HCQ) with a cumulative dose of 164 g. In addition, 2 months earlier, she had been diagnosed with connective tissue disease-related pulmonary artery hypertension. We performed an electrocardiogram and noted complete atrioventricular block. A transthoracic echocardiogram showed pulmonary hypertension. Due to the unclear nature of the pulmonary hypertension, we performed cardiac catheterization and right ventricular endomyocardial biopsy. Cardiac catheterization revealed that pulmonary hypertension was due to left ventricular dysfunction. Electron microscopy of the cardiac biopsy demonstrated a curvilinear body, diagnostic of HCQ toxicity. Thus, we diagnosed pulmonary hypertension owing to left heart disease and complete atrioventricular block that resulted from HCQ toxicity. Insertion of a permanent pacemaker and discontinuation of HCQ dramatically improved the disease state. This is the first report of this type of cardiac complication with HCQ; it raises the awareness that HCQ may cause cardiac complications despite a small cumulative dose relative to doses reported in other cases. Furthermore, we emphasize that cardiac catheterization played a critical role in the differential diagnosis from pulmonary hypertension associated with connective tissue disease.