Spontaneous T wave alternans in a patient with Brugada syndrome--responses to intravenous administration of class I antiarrhythmic drug, glucose tolerance test, and atrial pacing.

Spontaneous T wave alternans in Brugada syndrome. A 43-year-old man with an episode of syncope showed ECG patterns of coved-type ST elevation in leads V1-V3 and right bundle branch block pattern. The patient had spontaneous T wave alternans at baseline, and T wave alternans diminished with distinct development of ST elevation after administration of Na+ channel blocker, and during oral glucose load and atrial pacing. Na+ channel mutation may contribute to the genesis of his ECG changes.