title: Long-term follow-up of patients with P-R prolongation after catheter ablation of slow pathway for atrioventricular node re-entrant tachycardia.
abstract: BACKGROUND
  Long-term impact of interval between P wave and R wave (P-R) prolongation on prognosis of patients with successful catheter ablation of slow atrioventricular nodal pathway was investigated.
  
  
  METHODS
  Among 436 patients undergoing slow-pathway ablation for atrioventricular node re-entrant tachycardia (AVNRT), 17 (3.9%) experienced permanent P-R prolongation. Ablation target sites where conduction block was induced were located in mid- or anteroseptum. Fast junctional rhythm with ventriculoatrial conduction block was observed in eight patients immediately before atrioventricular block.
  
  
  RESULTS
  Antegrade slow-pathway conduction was eliminated in 16 patients, and retrograde fast- and slow-pathway conduction was abolished in all patients. There was no recurrence of AVNRT after an average of 38 +/- 12 month follow-up. There was no deterioration of atrioventricular block in these patients. Average PR interval prior to hospital discharge and at the end of follow-up was 0.24 +/- 0.02 sec and 0.23 +/- 0.02 sec, respectively (p >0.05). Left ventricular ejection fraction remained unchanged in these patients (p >0.05).
  
  
  CONCLUSIONS
  Radiofrequency catheter ablation of slow pathway for AVNRT is associated with a small risk of atrioventricular block. PR prolongation after successful slow-pathway ablation is associated with benign prognosis.
authors.affiliation: Department of Cardiology, The Affiliated Hospital of Weifang Medical College, Weifang City, Shandong Province, People's Republic of China. lwang@csu.edu.au
authors.forename: Lexin
authors.initials: L
authors.lastname: Wang
authors.forename: Jingtian
authors.initials: J
authors.lastname: Li
authors.forename: Rongguo
authors.initials: R
authors.lastname: Yao
authors.forename: Shukai
authors.initials: S
authors.lastname: Song
authors.forename: Zhanli
authors.initials: Z
authors.lastname: Guo
mesh_terms: D000328:Adult; D017115:Catheter Ablation / Q000009:adverse effects; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006327:Heart Block / Q000209:etiology*; D006329:Heart Conduction System / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D013611:Tachycardia, Atrioventricular Nodal Reentry / Q000628:therapy*