Hypothyroidism-induced reversible dilated cardiomyopathy.

Dilated cardiomyopathy (DCM) is an idiopathic condition that results from impaired ventricular systolic function. Thyroid diseases have been known to cause myriad changes in the structure and function of the heart. Diastolic dysfunction is a common abnormality reported in hypothyroidism. However, hypothyroidism-induced DCM and systolic dysfunction is an uncommon phenomenon, especially as the initial presenting manifestation of hypothyroidism. The current article describes the case of a young female who presented with symptoms of heart failure and was diagnosed as having DCM as echocardiography revealed left ventricular global hypokinesia and severely depressed systolic function. Thyroid profile revealed a grossly elevated thyroid-stimulating hormone (TSH) value of 313 μIU/ml; free thyroxine (fT4) was 0.220 ng/dl. The present case presented with DCM as the initial presentation of hypothyroidism and improved significantly after five months of levothyroxine replacement therapy.