title: High-amplitude pace mapping increases safety of radiofrequency catheter ablation of parahisian ectopic foci.
abstract: BACKGROUND
  The objective of the study is to assess the efficacy of high-amplitude pace mapping in terms of the atrioventricular (AV) block risk after radiofrequency catheter ablation (RCA) of parahisian ectopic foci.
  
  
  METHODS
  Twenty patients aged 38 ± 14 years with no structural heart disease underwent RCA of parahisian ectopic foci. All the patients were randomized into two groups: Group I (n = 11) had RCA performed in the region defined as ectopic focus by electrophysiology study and Group II (n = 9) had high-amplitude pacing performed in the region of "perfect" mapping. RCA was done only at the sites where high-amplitude pacing revealed the absence of His bundle capture.
  
  
  RESULTS
  In group I, the efficacy of RCA was 54.5% and it was 100% in group II (P = 0.0195). Group II had no complications; in group I there were 27% of AV blocks (P = 0.0893). The late recurrence of ectopic activity was comparable in both groups: 3 (27%) and 2 (22%), respectively (P = 0.7953). In all the cases of recurrent ectopic activity and in all the cases of ineffective primary procedure, group I had effective reablation procedures performed using high-amplitude pace mapping. The overall efficacy in terms of repeated procedures was 90%.
  
  
  CONCLUSIONS
  High-amplitude pace mapping increases primary and secondary efficacy of parahisian ectopic foci RCA and decreases the risk of AV block development. (PACE 2012;35:1458-1463).
authors.affiliation: Research Institute for Complex Issues of Cardiovascular Diseases, Kemerovo, Russian Federation. sergei_mamchur@mail.ru
authors.forename: Sergey E
authors.initials: SE
authors.lastname: Mamchur
authors.forename: Mikhail Y
authors.initials: MY
authors.lastname: Kurilin
mesh_terms: D000328:Adult; D054537:Atrioventricular Block / Q000209:etiology / Q000517:prevention & control; D002036:Bundle of His / Q000503:physiopathology* / Q000601:surgery*; D002304:Cardiac Pacing, Artificial; D017115:Catheter Ablation / Q000379:methods*; D016009:Chi-Square Distribution; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D061214:Patient Safety; D012008:Recurrence; D013613:Tachycardia, Ectopic Junctional / Q000503:physiopathology* / Q000601:surgery*