title: Selective myocardial isolation and ventricular fibrillation.
abstract: BACKGROUND
  Few experimental studies have analyzed the effects of selective radiofrequency (RF) lesions upon ventricular fibrillation (VF). The RF-induced isolation of selected zones would make it possible to determine whether these zones are essential for existence of the arrhythmia.
  
  
  METHODS
  In 31 Langendorff-perfused rabbit hearts, the characteristics and inducibility of VF were analyzed before and after the induction of RF lesions comprising: (1) the posterior zone of the septum and of the walls of both ventricles (n = 10); (2) the anterior zone of the septum and of the walls of both ventricles (n = 11); and (3) the midseptal zone (n = 10).
  
  
  RESULTS
  Complete isolation of the zone encompassed by the lesions was obtained in 5, 6, and 5 experiments of series 1, 2, and 3, respectively. In these experiments, the arrhythmia was only induced from within the zone encompassed by the lesions in one experiment belonging to series 2 (P < 0.05 with respect to baseline). In contrast, in all but one of the cases in series 2, VF could be induced from outside the isolated zone (ns vs baseline). Partial isolation was obtained in five experiments of each series. In these experiments, on pacing from within the partially isolated zone, sustained VF was not induced in any experiment (P < 0.05 with respect to baseline), while in all cases VF could be induced on pacing from the external zone (ns vs baseline).
  
  
  CONCLUSIONS
  In the experimental model used, the three zones studied were not essential for maintaining VF. In most cases, their partial or total isolation avoided inducibility of the arrhythmia in those zones, though not in the remaining myocardium.
authors: Service of Cardiology, Valencia University Clinic Hospital, Valencia, Spain. Francisco.J.Chorro@uv.es
authors: Francisco J
authors: FJ
authors: Chorro
authors: Estrella
authors: E
authors: Blasco
authors: Isabel
authors: I
authors: Trapero
authors: Joaquín
authors: J
authors: Cánoves
authors: Angel
authors: A
authors: Ferrero
authors: Luis
authors: L
authors: Mainar
authors: Luis
authors: L
authors: Such-Miquel
authors: Juan
authors: J
authors: Sanchis
authors: Vicente
authors: V
authors: Bodí
authors: José M
authors: JM
authors: Cerdá
authors: Antonio
authors: A
authors: Alberola
authors: Luis
authors: L
authors: Such
mesh_terms: D000818:Animals; D018780:Body Surface Potential Mapping; D017115:Catheter Ablation; D006329:Heart Conduction System / Q000503:physiopathology* / Q000601:surgery*; D011817:Rabbits; D014693:Ventricular Fibrillation / Q000503:physiopathology* / Q000601:surgery*