LAUSR

and normal echocardiogram prior to initiating therapy who developed dilated cardiomyopathy after 25 months of treatment. The patient presented with exercise-induced dyspnea. Magnetic resonance imaging showed left ventricular dilatation with a slightly depressed ejection fraction, normal wall thickness, and no focal or segmental fibrosis in the late enhancement sequences. The drug was withdrawn and ventricular volumes returned to normal during subsequent follow-up. Hydroxychloroquine-induced cardiomyopathy was therefore suspected clinically. Endomyocardial biopsy was not performed. These 3 cases of hydroxychloroquine-induced myocardial toxicity highlight the importance of periodic clinical assessment of these patients (even those who have been under treatment for a few months). In the event of minimal clinical suspicion, the use of imaging techniques should be considered to assess whether myocardial involvement is present.