title: Electrical isolation of a substrate after myocardial infarction: a novel ablation strategy for unmappable ventricular tachycardias--feasibility and clinical outcome.
abstract: OBJECTIVE
  Catheter ablation can abolish clinical ventricular tachycardia (VT) in patients after myocardial infarction (MI). However, VT frequently recurs after ablation. The best ablation strategy is still unknown, particularly in patients with unmappable VTs. We hypothesized that isolation of the arrhythmogenic substrate would be a feasible and effective ablation strategy for the treatment of ischaemic VT.
  
  
  RESULTS
  Twelve patients (54 ± 8 years, left ventricular ejection fraction, LVEF 32 ± 13%) underwent catheter ablation for sustained VT (anterior MI = 10, inferior MI = 2). All patients had recurrent defibrillator shocks, including electrical storms in seven patients, despite anti-arrhythmic drugs. During electrophysiological study, 3 ± 2 VTs were induced. Three-dimensional mapping of the left ventricle revealed a low-voltage (<1.5 mV) area with fractionated electrograms and late potentials, with a mean area of 62 ± 20 cm(2). Isolation of the entire low-voltage area was attempted with a circumferential line along the low-voltage area border-zone. Substrate isolation was successfully achieved in 6 of 12 (50%) patients. Focal discharge within the isolated area was demonstrated in three of six (50%) patients. During a median follow-up of 479 [297; 781] days, 8 of 12 patients (66.7%) remained free of VT recurrence after a single procedure. In five of the six patients (83.3%) with successful substrate isolation, there were no VT recurrences when compared with three of the six patients (50%) with no substrate isolation.
  
  
  CONCLUSIONS
  Electrical isolation of the entire substrate is feasible and appears to be an effective treatment in patients with late VT after MI.
authors.affiliation: Department of Cardiology, Asklepios Klinik St Georg, Lohmuehlenstr 5, 20099 Hamburg, Germany tilz6@hotmail.com.
authors.forename: Roland Richard
authors.initials: RR
authors.lastname: Tilz
authors.affiliation: Department of Cardiology, Asklepios Klinik St Georg, Lohmuehlenstr 5, 20099 Hamburg, Germany.
authors.forename: Hisaki
authors.initials: H
authors.lastname: Makimoto
authors.affiliation: Department of Cardiology, Asklepios Klinik St Georg, Lohmuehlenstr 5, 20099 Hamburg, Germany.
authors.forename: Tina
authors.initials: T
authors.lastname: Lin
authors.affiliation: Department of Cardiology, Asklepios Klinik St Georg, Lohmuehlenstr 5, 20099 Hamburg, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Rillig
authors.affiliation: Department of Cardiology, Asklepios Klinik St Georg, Lohmuehlenstr 5, 20099 Hamburg, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Deiss
authors.affiliation: Department of Cardiology, Asklepios Klinik St Georg, Lohmuehlenstr 5, 20099 Hamburg, Germany.
authors.forename: Erik
authors.initials: E
authors.lastname: Wissner
authors.affiliation: Department of Cardiology, Asklepios Klinik St Georg, Lohmuehlenstr 5, 20099 Hamburg, Germany.
authors.forename: Shibu
authors.initials: S
authors.lastname: Mathew
authors.affiliation: Department of Cardiology, Asklepios Klinik St Georg, Lohmuehlenstr 5, 20099 Hamburg, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Metzner
authors.affiliation: Department of Cardiology, Asklepios Klinik St Georg, Lohmuehlenstr 5, 20099 Hamburg, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Rausch
authors.affiliation: Department of Cardiology, Asklepios Klinik St Georg, Lohmuehlenstr 5, 20099 Hamburg, Germany.
authors.forename: Karl-Heinz
authors.initials: KH
authors.lastname: Kuck
authors.affiliation: Department of Cardiology, Asklepios Klinik St Georg, Lohmuehlenstr 5, 20099 Hamburg, Germany.
authors.forename: Feifan
authors.initials: F
authors.lastname: Ouyang
mesh_terms: D000368:Aged; D017115:Catheter Ablation / Q000379:methods*; D022062:Electrophysiologic Techniques, Cardiac; D005240:Feasibility Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology; D011237:Predictive Value of Tests; D012008:Recurrence; D012086:Reoperation; D013318:Stroke Volume; D017180:Tachycardia, Ventricular / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology / Q000601:surgery*; D013997:Time Factors; D016896:Treatment Outcome; D016277:Ventricular Function, Left
keywords: Catheter ablation; Ischaemic heart disease; Substrate isolation; Ventricular tachycardia