Irreversible Thyrotoxic Dilated Cardiomyopathy: Case Reports and Review of Literature.

Irreversible dilated cardiomyopathy due to thyrotoxicosis is a rare clinical entity. We report two cases, one who presented with congestive cardiac failure and other presented with severe left ventricular dysfunction and atrial fibrillation. Both cases were diagnosed as dilated cardiomyopathy with severe left ventricular dysfunction (ejection fraction <30%) due to thyrotoxicosis. Inspite of vigorous medical therapy, there was only symptomatic improvement. Restoration of euthyroid levels did not revert the cardiomyopathy but led to definite clinical improvement.