ACTA ENDOCRINOLOGICA (BUC)

Complete heart block associated with hyperthyroidism is infrequent, and the diagnosis of hyperthyroidism is usually not considered in the absence of tachycardia. A 55-year-old woman was admitted to our emergency clinic with dizziness and syncope attack. Her electrocardiogram showed complete heart block.\r\nHyperthyroidism had been diagnosed, and she had been treated with propylthiouracil as an anti-thyroid treatment 3 years ago, although she had not taken this drug during the last 2 months. Her thyroid function tests showed hyperthyroidism. Antithyroid treatment was started again. Her rhythm returned from complete atrioventricular block to normal sinus rhythm\r\non the seventh day of hospitalization.