title: Multiple AV nodal pathways in patients with AV nodal reentrant tachycardia--more common than expected?
abstract: OBJECTIVE
  It was the purpose of this study to determine the incidence of more than two AV nodal pathways in patients with AVNRT.
  
  
  RESULTS
  In 78 consecutive patients with AV-nodal reentrant tachycardias (AVNRT) (50 females, 28 males, mean age 52.8 +/- 14.6 years), the number of sudden AH increases by 50 ms or more (AH-jump) was analysed during atrial extrastimulation. The incidence of two AV nodal pathways was accepted to be present in patients with AVNRT without an AH-jump ('smooth curve'). The following forms of tachycardia were induced: a typical AVNRT (slow-fast) in 67 patients, an atypical AVNRT (fast-slow) in 12 patients and a slow-slow-AVNRT in 4 patients. Five patients had two forms of AVNRT. 47 patients (60.3%) showed two AV nodal pathways, 27 patients (34.6%) had three AV-nodal pathways and 4 patients (5.1%) exhibited four AV-nodal pathways. For successful catheter ablation of AVNRT in patients with more than two pathways, more radiofrequency energy applications were required (9.2 +/- 6.3) compared with patients with only two pathways (6.7 +/- 4.8). Furthermore, in patients with more than two AV-nodal pathways, the catheter intervention resulted more frequently in a modulation of slow pathway conduction than in an ablation of the slow pathway(s).
  
  
  CONCLUSIONS
  The incidence of more than two AV-nodal pathways in patients with AVNRT was unexpectedly high at about 40%. Thus, these tachycardias require a meticulous electrophysiological evaluation for successful ablation.
authors.affiliation: Department of Cardiology and Angiology, University of Halle-Wittenberg, Germany. konstantin.heinroth@medizin.uni-halle.de
authors.forename: K M
authors.initials: KM
authors.lastname: Heinroth
authors.forename: K
authors.initials: K
authors.lastname: Kattenbeck
authors.forename: I
authors.initials: I
authors.lastname: Stabenow
authors.forename: H J
authors.initials: HJ
authors.lastname: Trappe
authors.forename: P
authors.initials: P
authors.lastname: Weismüller
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017115:Catheter Ablation; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006329:Heart Conduction System / Q000473:pathology* / Q000503:physiopathology / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D013611:Tachycardia, Atrioventricular Nodal Reentry / Q000473:pathology* / Q000503:physiopathology / Q000601:surgery