Primary Hypothyroidism: Uncommon Presentation With Reversible Dilated Cardiomyopathy in a Young Subject

Most patients with dilated cardiomyopathy have a poor prognosis that is associated with progressive and irreversible myocardial dysfunction. rarely, a reversible metabolic etiology that is amenable to specific therapy is identified. thyroid hormones have many effects on the heart. although cardiac output is reduced in hypothyroidism, heart failure is relatively rare due to the lower demand for peripheral oxygen delivery. we report a 14-year-old girl who presented with dilated cardiomyopathy (dcm) and was determined to have primary hypothyroidism, for whom cardiac function improved significantly after levothyroxine replacement therapy. our case underscores the necessity of thyroid function testing to examine the etiology of nonischemic dcm, even in young subjects.