title: Bipolar irrigated radiofrequency ablation: a therapeutic option for refractory intramural atrial and ventricular tachycardia circuits.
abstract: BACKGROUND
  Irrigated radiofrequency (RF) ablation can be insufficient to eliminate intramurally located septal atrial flutter (AFL) and ventricular tachycardia (VT) circuits. Bipolar ablation between 2 ablation catheters may be considered for such circuits.
  
  
  OBJECTIVE
  To evaluate the utility of bipolar irrigated ablation to terminate arrhythmias resistant to unipolar ablation.
  
  
  METHODS
  In vitro: Bipolar and sequential unipolar RF ablation lesions were placed on porcine ventricular tissue in a saline bath to assess for lesion transmurality. Clinical: 3 patients with atypical septal flutter (AFL), 4 patients with septal VT, and 2 with left ventricle free-wall VT, all of whom failed sequential unipolar RF ablation, underwent bipolar RF ablation using irrigated catheters placed on either surface of the interatria/interventricular septum and left ventricle free-wall, respectively.
  
  
  RESULTS
  In vitro: Bipolar RF was found to be more likely to achieve transmural lesions (82% vs 33%; P = .001) and could do so in tissues with thicknesses of up to 25 mm. Clinical: All 5 AFLs (3 patients) were successfully terminated with bipolar RF. In follow-up, AFL recurred in 2 of the 3 patients and atrial fibrillation and AFL recurred in 1 of the 3. All 3 thereafter underwent repeat procedures with successful maintenance of sinus rhythm in 2 of the 3 patients (6-month follow-up). In the VT subgroup, 5 of 6 septal VTs and 2 of 3 free-wall VTs were terminated successfully during ablation. In follow-up (12 months), 2 of the 4 patients in the septal bipolar group and 1 of the 2 patients in the free-wall group remained free of VT.
  
  
  CONCLUSIONS
  Bipolar RF can be used to terminate arrhythmias in select patients with tachyarrhythmias.
authors.affiliation: Helmsley Electrophysiology Center, Mount Sinai School of Medicine, New York, New York 10029, USA.
authors.forename: Jacob S
authors.initials: JS
authors.lastname: Koruth
authors.forename: Srinivas
authors.initials: S
authors.lastname: Dukkipati
authors.forename: Marc A
authors.initials: MA
authors.lastname: Miller
authors.forename: Petr
authors.initials: P
authors.lastname: Neuzil
authors.forename: Andre
authors.initials: A
authors.lastname: d'Avila
authors.forename: Vivek Y
authors.initials: VY
authors.lastname: Reddy
mesh_terms: D000368:Aged; D000818:Animals; D001282:Atrial Flutter / Q000503:physiopathology / Q000601:surgery*; D017115:Catheter Ablation / Q000379:methods*; D004195:Disease Models, Animal; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006329:Heart Conduction System / Q000503:physiopathology / Q000601:surgery*; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D013552:Swine; D017180:Tachycardia, Ventricular / Q000503:physiopathology / Q000601:surgery*; D016896:Treatment Outcome; D054088:Ventricular Septum / Q000294:innervation*