FACILITATION OF SUSTAINED BUNDLE-BRANCH REENTRY BY ATRIAL-FIBRILLATION

Sustained Bundle Branch Reentry. An electrophysiologic evaluation was performed in a patient with an idiopathic dilated cardiomyopathy and s yncope. Ventricular tachycardia was not inducible despite the use of a variety of pacing maneuvers during sinus rhythm. Only after the elect rical induction of atrial fibrillation did sustained bundle branch ree ntrant tachycardia (with both right and left bundle branch block QRS c onfigurations) spontaneously occur and become reproducibly induced dur ing right ventricular pacing. Ablation of the right bundle branch elim inated reproducibility of the tachycardia.