Dome-and-dart T Waves and Hyperthyroidism - A Case Report

We briefly describe a case of a 31-year-old man with persistent hyperthyroidism, despite medical treatment with high dose methimazole. Twelve-lead 24-hour Holter monitoring showed bifid (or dome-and-dart) T waves and echocardiography revealed mild left ventricle dilatation. Hyperthyroidism was eventually treated with total thyroidectomy, and thereafter, T waves became normal and the left ventricle returned to normal dimensions. Hyperthyroidism should be considered among the differential diagnoses when T wave abnormalities are observed on electrocardiogram and when mild left ventricle dilatation is observed on an echocardiogram. The correction of hyperthyroidism can reverse these abnormalities.