BUNDLE-BRANCH REENTRY TACHYCARDIA AND POSSIBLE SUSTAINED INTERFASCICULAR REENTRY TACHYCARDIA WITH A SHARED UNUSUAL INDUCTION-PATTERN

A case of bundle branch reentry tachycardia with an unusual induction pattern is presented. Unlike typical cases of this arrhythmia in which tachycardia is usually inducible with routine programmed ventricular stimulation and/or short-long sequences, tachycardia in this case was inducible only with atrial stimulation. It also arose spontaneously du ring atrial flutter and during isoproterenol administration. After abl ation of the right bundle, possible interfascicular reentry tachycardi a with a similar induction pattern was observed. This tachycardia was successfully ablated in the region of the posterior fascicle of the le ft bundle branch.