Transition from purkinje fiber-related rapid polymorphic ventricular tachycardia to sustained monomorphic ventricular tachycardia in a patient with a structurally normal heart: a case report.

We describe a 17-year-old woman with a structurally normal heart in which short-sustained rapid polymorphic ventricular tachycardias (VTs) were repetitively provoked by an antiarrhythmic agent, pilsicainide, and spontaneously changed into a sustained monomorphic VT. The latter was terminated by verapamil and was shown to be due to reentry by entrainment. Those two VTs originated from the Purkinje fibers in the left ventricular septum. Radiofrequency catheter ablation guided by the diastolic double potentials eliminated both VTs. Neither tachycardia recurred over a 5-month follow-up period or during antiarrhythmic drug challenge tests at 1 week, 1 month, and 3 months after the ablation.