title: Primary radiofrequency ablation of ventricular tachycardia early after myocardial infarction: evaluation in an ovine model.
abstract: BACKGROUND
  Ventricular tachycardia (VT) is a significant complication of myocardial infarction. Radiofrequency ablation for postinfarct VT is reserved for drug refractory VT or VT storms. Our hypothesis is that radiofrequency ablation in the early postinfarct period could abolish or diminish late recurrences of VT.
  
  
  RESULTS
  Myocardial infarct was induced by balloon occlusion of the left anterior descending artery in 35 sheep. The 25 survivors underwent programmed ventricular stimulation and electroanatomical mapping 8 days postinfarct. Animals with inducible VT (12 out of 25 animals) underwent immediate radiofrequency ablation. Further VT inductions were performed 100 and 200 days postinfarct. At day 8, 3.0±0.9 VT morphologies per animal were inducible. All were successfully ablated with 24±6 applications of radiofrequency energy. All had ablations on the left ventricular endocardium, and 67% had ablations on the right ventricular aspect of the interventricular septum. All targeted arrhythmias were successfully ablated acutely. One animal was euthanized because of hypotension from a serious pericardial effusion. The other 11 survived and remained arrhythmia free on subsequent inductions on the 100th and 200th days (P<0.001). The 13 animals without inducible VT remained noninducible at the subsequent studies. A historical control arm of 9 animals with inducible VT at day 8 remained inducible at day 100.
  
  
  CONCLUSIONS
  Radiofrequency ablation on the eighth day after infarction abolished inducibility of VT at late induction studies ≤200 days in an ovine model. Early identification and ablation of VT after infarction may prevent or reduce late ventricular arrhythmias but needs to be validated in clinical studies.
authors.affiliation: Westmead Hospital and the University of Sydney, Sydney, Australia.
authors.forename: Calvin H C
authors.initials: CH
authors.lastname: Hsieh
authors.forename: Ee-May
authors.initials: EM
authors.lastname: Chia
authors.forename: Kaimin
authors.initials: K
authors.lastname: Huang
authors.forename: Juntang
authors.initials: J
authors.lastname: Lu
authors.forename: Michael
authors.initials: M
authors.lastname: Barry
authors.forename: Jim
authors.initials: J
authors.lastname: Pouliopoulos
authors.forename: David L
authors.initials: DL
authors.lastname: Ross
authors.forename: Stuart P
authors.initials: SP
authors.lastname: Thomas
authors.forename: Pramesh
authors.initials: P
authors.lastname: Kovoor
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000818:Animals; D017115:Catheter Ablation; D004195:Disease Models, Animal; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac; D008297:Male; D009203:Myocardial Infarction / Q000150:complications; D055502:Secondary Prevention; D012756:Sheep; D017180:Tachycardia, Ventricular / Q000209:etiology / Q000601:surgery*; D013997:Time Factors
keywords: catheter ablation; myocardial infarction