Rapid ventricular tachycardia due to His-Purkinje reentry.
Two patients developed rapid His-Purkinje reentrant tachycardia during programmed ventricular stimulation for evaluation of recurrent ventricular tachycardia. In Patient 1, His-Purkinje reentry induced a morphologically distinct ventricular tachycardia which may have been a reentrant circuit operating independently for several cardiac cycles. His-Purkinje reentry was not inducible in Patient 2 until lidocaine was given. Following lidocaine administration, sustained His-Purkinje reentrant tachycardia was initiated by 2 premature ventricular stimuli. The tachycardia was rapid (240 beats per minute) and required cardioversion.