Analysis of junctional beats during slow pathway ablation: Illuminating the mechanism of typical and atypical AV nodal re-entrant tachycardia.

Background: Junctional rhythm (JR) frequently occurs during radiofrequency (RF) ablation procedures targeting the slow pathway (SP) for atrioventricular nodal re-entrant tachycardia (AVNRT), signaling successful ablation. Two types of JR have been noticed: typical JR as His activation preceding atrial activation, and atypical JR as atrial activation preceding the His activation. Nevertheless, the origin and characteristics of JR remain incompletely defined.