Demonstration of reentry within the right bundle branch in man.

Reentry within the right bundle branch which, to our knowledge is a hitherto undescribed mechanism of His-Purkinje reentry in man, was elicited during programmed right ventricular stimulation. Electrophysiologic analysis excluded atrioventricular nodal reentry. His bundle reentry, reentry involving both bundle branches, and intraventricular micro-reentry.