title: Change in delay of atrioventricular conduction after radiofrequency catheter ablation for atrioventricular nodal re-entry tachycardia.
abstract: OBJECTIVE
  To monitor atrioventricular conduction after radiofrequency ablation for atrioventricular nodal re-entry tachycardia.
  
  
  METHODS
  Measurement of PR interval from 12 lead surface electrocardiograms before; at 0, 24, 48, 72, and 96 hours; and at 1 and 6 months after radiofrequency ablation.
  
  
  METHODS
  40 consecutive patients with atrioventricular nodal re-entry tachycardia. The anterior approach was used in 23 patients, the posterior approach in 17.
  
  
  RESULTS
  With the anterior approach the PR interval increased significantly and progressively until 48 hours after ablation (maximum 282 (SD 62.2) ms, before ablation 142 (29.5) ms; P < 0.0001). Up to 96 hours no further change was observed, but one month after ablation the PR interval had decreased to a value not significantly different from that 24 hours after the procedure (231 (51.2) ms). In one patient total atrioventricular block developed 24 hours after an uncomplicated procedure and a permanent pacemaker was implanted. With the posterior approach the PR interval increased slightly in the first 24 hours (156 (22.7) ms, before ablation 144 (21.2) ms P = 0.004), but it had returned to preablation values at 1 month. One patient developed second degree atrioventricular block during the first 24 hours after ablation, despite delivery of all radiofrequency pulses posterior to Koch's triangle at sites without His bundle deflection. PR intervals at 6 months did not differ significantly from the values at 1 month.
  
  
  CONCLUSIONS
  After the anterior approach the progressive delay in atrioventricular conduction up to 48 hours after radiofrequency ablation for atrioventricular nodal re-entry tachycardia warrants continuous in hospital monitoring of patients for at least two days after the procedure.
authors.affiliation: Heart-Lung Institute, University Hospital Utrecht, The Netherlands.
authors.forename: T A
authors.initials: TA
authors.lastname: Simmers
authors.forename: E F
authors.initials: EF
authors.lastname: Wever
authors.forename: F H
authors.initials: FH
authors.lastname: Wittkampf
authors.forename: R N
authors.initials: RN
authors.lastname: Hauer
mesh_terms: D001283:Atrioventricular Node / Q000503:physiopathology*; D017115:Catheter Ablation; D004562:Electrocardiography; D006801:Humans; D011184:Postoperative Period; D013611:Tachycardia, Atrioventricular Nodal Reentry / Q000503:physiopathology / Q000601:surgery*