Abstract
A 77-year-old man was diagnosed as having hypothyroidism. An electrocardiogram obtained at the time of the first examination revealed Brugada electrocardiographic waveforms in leads V1 to V3. When pilsicainide hydrochloride loading changed the waveforms of the electrocardiographic ST segment, this result suggested an abnormality of the cardiac muscle sodium channels. The Brugada electrocardiographic waveforms disappeared with the normalization of thyroid function. This case is the first report ever of hypothyroidism that presented Brugada electrocardiographic waveforms. The results obtained in this case suggested that thyroid functions changed the waveforms of the electrocardiogram because of its effect on myocardial ion channels.
