Atypical atrial resetting with ventricular extrastimulus during tachycardia: What is the mechanism?

Abstract

This atypical atrial resetting with ventricular extrastimulus delivered during supraventricular tachycardia is characterized by no capture of local ventricular deflection contralateral to the earliest atrial site and is a finding unmasking the presence of a nodoventricular pathway, the ventricular insertion of which is located apically, away from the mitral annulus.