[Two cases of hypothyroidism with echocardiographic features similar to cardiomyopathy: one simulates hypertrophic and the other dilated cardiomyopathy].

Two cases of hypothyroidism with echocardiographic features similar to cardiomyopathy were presented. In case 1 (a 68 year-old woman), moderate pericardial effusion and myocardial hypertrophy were observed on admission. In case 2 (a 69 year-old woman), dilation of the left ventricle, hypokinesis of the interventricular septum and the left ventricular free wall, and reduced left ventricular systolic function were observed on admission. These echocardiographic findings were similar to hypertrophic or dilated cardiomyopathy. In the two cases, after recovery to euthyroid state, these echocardiographic abnormalities returned to normal. We concluded that hypothyroidism led to a reversible hypertrophic or dilated cardiomyopathy, and that echocardiographic study was useful for diagnosis and for following up cardiac manifestations of hypothyroidism.