Reentry in a pulmonary vein as a possible mechanism of focal atrial fibrillation.

The case of an 18-year-old woman with recurrent idiopathic catecholamine-sensitive paroxysmal atrial fibrillation is reported. Recordings of multiple initiations of atrial fibrillation at the proximal part of the right superior pulmonary vein suggested local reentry in the vein as the mechanism of atrial fibrillation. A single radiofrequency pulse delivered at this site resulted in definite cure of the arrhythmia.