title: Analysis during sinus rhythm of critical sites in reentry circuits of postinfarction ventricular tachycardia.
abstract: BACKGROUND
  Critical sites within reentry circuits of postinfarction ventricular tachycardia (VT) were identified during sinus rhythm (SR) and VT to determine whether electrogram characteristics during SR may be helpful in identifying successful ablation sites.
  
  
  METHODS
  In 33 patients (mean age 67 +/- 11 yrs) with prior infarction, mapping and radiofrequency (RF) catheter ablation of 57 hemodynamically-tolerated VT's (cycle length 478 +/- 96) were performed. The morphologies of electrograms (EGM) at sites of concealed entrainment (CE) were compared during SR and VT. RF energy was delivered at 94 sites (51 successful and 43 unsuccessful ablation sites).
  
  
  RESULTS
  During SR, isolated potentials (IP), but not late potentials (LP) recorded via the mapping catheter, were associated with successful ablation. At 29/39 sites with an IP during sinus rhythm, an isolated diastolic potential (IDP) also was present during VT, whereas at 4 sites IP's were present only during SR (p < 0.001). At 11/29 sites where isolated potentials were present during SR and VT, the morphology of the isolated potential during VT and SR was similar; and all but one of these sites were successful ablation sites (p = 0.01). The EGM amplitude during VT correlated with the amplitude during SR (R = 0.9, p < 0.001). An identical pacemap was present during SR at 33/94 sites; this was not associated with successful ablation.
  
  
  CONCLUSIONS
  SR mapping may be helpful in identifying critical sites of reentry in postinfarction VT. At sites within the reentry circuit, characteristics of sinus rhythm EGM's that are associated with successful ablation include the presence of IP's, but not the presence of LP's.
authors.affiliation: Division of Cardiology, JW Goethe University, Frankfurt, Germany. bogun@eudocamail.com
authors.forename: Frank
authors.initials: F
authors.lastname: Bogun
authors.forename: Birgit
authors.initials: B
authors.lastname: Bender
authors.forename: Yi-Gang
authors.initials: YG
authors.lastname: Li
authors.forename: Gerian
authors.initials: G
authors.lastname: Groenefeld
authors.forename: Stefan H
authors.initials: SH
authors.lastname: Hohnloser
authors.forename: Frank
authors.initials: F
authors.lastname: Pelosi
authors.forename: Bradley
authors.initials: B
authors.lastname: Knight
authors.forename: S Adam
authors.initials: SA
authors.lastname: Strickberger
authors.forename: Fred
authors.initials: F
authors.lastname: Morady
mesh_terms: D000200:Action Potentials; D000368:Aged; D017115:Catheter Ablation / Q000379:methods*; D022062:Electrophysiologic Techniques, Cardiac / Q000379:methods*; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications*; D011446:Prospective Studies; D017180:Tachycardia, Ventricular / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology / Q000601:surgery*; D016896:Treatment Outcome