title: Origin of junctional rhythm during radiofrequency ablation of atrioventricular nodal reentrant tachycardia in patients without structural heart disease.
abstract: Junctional rhythm is commonly observed during radiofrequency catheter ablation of the fast or slow pathways of atrioventricular nodal reentrant tachycardia (AVNRT). However, the origin of these beats remains unclear. We analyzed the retrograde atrial activation sequence of 16 patients (mean +/- SD: 41.2 +/- 18.9 years old) undergoing catheter ablation for typical AVNRT with detailed catheter mapping of the triangle of Koch. The earliest atrial activations were concordant during tachycardia and junctional rhythm in only 5 of 16 patients. The findings suggest that junctional rhythm is unlikely to represent direct stimulation of the atrioventricular (AV) node via a discrete slow pathway but rather results from enhanced automaticity from > or =1 sites in the AV nodal transitional zone. The ensuing atrial activation pattern results from anisotropic spread from these sites. In addition, these data imply that the original concept of the AV node comprising 2 anatomically defined pathways may not be valid, and that a functionally defined pathway model may be a more accurate representation.
authors.affiliation: Harvard-Thorndike Institute of Electrophysiology, Beth Israel Hospital, Harvard Medical School, Boston, Massachusetts 02215, USA.
authors.forename: N G
authors.initials: NG
authors.lastname: Boyle
authors.forename: F
authors.initials: F
authors.lastname: Anselme
authors.forename: K
authors.initials: K
authors.lastname: Monahan
authors.forename: P
authors.initials: P
authors.lastname: Papageorgiou
authors.forename: M
authors.initials: M
authors.lastname: Zardini
authors.forename: J
authors.initials: J
authors.lastname: Zebede
authors.forename: M E
authors.initials: ME
authors.lastname: Josephson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017115:Catheter Ablation; D004562:Electrocardiography; D005260:Female; D006325:Heart Atria / Q000294:innervation; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D013611:Tachycardia, Atrioventricular Nodal Reentry / Q000503:physiopathology / Q000601:surgery*