Complications of Untreated Hypothyroidism (Hashimoto's Thyroiditis)

Death associated with untreated hypothyroidism with no overt cardiovascular dysfunction is a rare occurrence and is usually classified as unexplained. Degenerative changes in the myocardium associated with hypothyroidism have not been reported in the English language literature since 1957. Historically, this was referred to as myxedema heart disease. This is a case report of untreated Hashimoto's thyroiditis resulting in marked histological changes associated with cardiac dysfunction causing death.