Identification of concealed posteroseptal kent pathways by comparison of ventriculoatrial intervals from apical and posterobasal right ventricular sites

Abstract

Background: The differential diagnosis of supraventricular tachycardia with concentric atrial activation usually requires the inducibility of sustained tachycardia and needs a complex and time-consuming electrophysiological evaluation. To develop a simple test to establish if ventriculoatrial conduction uses a posteroseptal accessory pathway or the normal conduction system, we compared the ventriculoatrial intervals during right ventricular pacing from apical and posterobasal sites. Methods and Results: Continuous pacing was performed from an apical and a posterobasal right ventricular site in 34 patients with retrograde conduction over the normal conduction system (group A) and in 22 patients with conduction over a posteroseptal accessory pathway (group B). During apical pacing, ventriculoatrial intervals in group A (176±40 milliseconds) were not significantly different than those in group B (197±47 milliseconds, P=NS). During posterobasal pacing, group B patients had significantly shorter ventriculoatrial intervals than group A patients (158±46 versus 197±39 milliseconds, P