Cycle length-dependent repolarization changes during atrial fibrillation in the Brugada syndrome.

This is a case report of a patient with Brugada syndrome who developed paroxysmal atrial fibrillation. During the episode, beat-to-beat changes in ventricular repolarization were observed. These changes were a paradoxical ST-segment alteration after a short-coupled ventricular beat. These findings, not reported before, may be helpful for the diagnosis of this syndrome.