Restrictive cardiomyopathy caused by chloroquine.

Abstract
A 59 year old white woman who had been treated with chloroquine phosphate for 25 years presented with signs of congestive heart failure and was diagnosed as having restrictive cardiomyopathy by non-invasive methods. Electron microscopy of a biopsy specimen of skeletal muscle showed lesions compatible with chloroquine myopathy. The patient died five weeks after presentation. Electron microscopy of heart tissue showed similar lesions to those of the skeletal muscle.