QT Prolongation as a Substrate for Syncope

A woman with paroxysmal atrial fibrillation, managed on dofetilide, suffered recurrent pre-syncope. Tracings from an implantable loop recorder provided recognition of torsades de pointes, and with cessation of dofetilide, her episodes of presyncope resolved. In the right context, as in use of a QT prolonging drug, acquired long QT syndrome and torsades de pointes may be an etiology of presyncope or syncope.