title: Ninety Seconds Could be the Optimal Duration for Ventricular Radiofrequency Ablation - Results From a Myocardial Phantom Model.
abstract: BACKGROUND
  Shallow lesions could be the predominant factor affecting the efficacy of ventricular radiofrequency (RF) ablations. The objective of this study was to assess lesion dimensions and overheating in extended RF ablations up to 180seconds and compare with that of conventional 30seconds ablations.
  
  
  METHODS
  The Navistar Thermocool irrigated catheter (Biosense Webster, CA, USA) was used in a previously validated myocardial phantom. Ablations were performed with 20W, 30W, 40W and 50W powers for 180seconds. The volume of lesion and overheating were measured at 530C and 800C isotherms respectively.
  
  
  RESULTS
  A total of 110 RF lesions were analysed. The lesion depth increment when ablation was extended from the conventional 30seconds to 90seconds were 31.2±0.2, 33.6±0.6, 36.3±1.8% of that at 30seconds, respectively for powers 30W, 40W and 50W. During 30W ablations, at 90seconds the lesion width and depth were 95.4±1.2%, 91.8±1.6% respectively of the final dimensions at 180seconds. Similar proportions were observed for 40W and 50W. During 40W ablations, the volume of overheating was 113±6% and 184±11% higher at 90seconds and 180seconds respectively compared to that at 30seconds and was 142±9% and 194±9% for 50W ablations.
  
  
  CONCLUSIONS
  Extending RF ablations up to 90seconds significantly increased the lesion depth (30-40%), however, overheating was present at 40W and 50W powers. Ablations beyond 90seconds provided little incremental value.
authors.affiliation: Cardiology Department, Westmead Hospital, Sydney, NSW, Australia; Sydney Medical School, University of Sydney, Sydney, NSW, Australia. Electronic address: apad7867@uni.sydney.edu.au.
authors.forename: Abhishek
authors.initials: A
authors.lastname: Bhaskaran
authors.affiliation: Cardiology Department, Westmead Hospital, Sydney, NSW, Australia; School of Electrical and Information Engineering, University of Sydney, Sydney, NSW, Australia.
authors.forename: Chrishan
authors.initials: C
authors.lastname: Nalliah
authors.affiliation: Cardiology Department, Westmead Hospital, Sydney, NSW, Australia; Sydney Medical School, University of Sydney, Sydney, NSW, Australia.
authors.forename: William
authors.initials: W
authors.lastname: Chik
authors.affiliation: Cardiology Department, Westmead Hospital, Sydney, NSW, Australia; Sydney Medical School, University of Sydney, Sydney, NSW, Australia.
authors.forename: Jim
authors.initials: J
authors.lastname: Pouliopoulos
authors.affiliation: Cardiology Department, Westmead Hospital, Sydney, NSW, Australia; Sydney Medical School, University of Sydney, Sydney, NSW, Australia.
authors.forename: Jeanette
authors.initials: J
authors.lastname: Ng
authors.affiliation: Cardiology Department, Westmead Hospital, Sydney, NSW, Australia; Sydney Medical School, University of Sydney, Sydney, NSW, Australia.
authors.forename: M A
authors.initials: MA
authors.lastname: Barry
authors.affiliation: Cardiology Department, Westmead Hospital, Sydney, NSW, Australia; Sydney Medical School, University of Sydney, Sydney, NSW, Australia.
authors.forename: Fazlur
authors.initials: F
authors.lastname: Nadri
authors.affiliation: Cardiology Department, Westmead Hospital, Sydney, NSW, Australia; Sydney Medical School, University of Sydney, Sydney, NSW, Australia.
authors.forename: Sara Al
authors.initials: SA
authors.lastname: Raisi
authors.affiliation: Cardiology Department, Westmead Hospital, Sydney, NSW, Australia; Sydney Medical School, University of Sydney, Sydney, NSW, Australia.
authors.forename: Juliana
authors.initials: J
authors.lastname: Dandach
authors.affiliation: Cardiology Department, Westmead Hospital, Sydney, NSW, Australia; Sydney Medical School, University of Sydney, Sydney, NSW, Australia.
authors.forename: Stuart
authors.initials: S
authors.lastname: Thomas
authors.affiliation: Cardiology Department, Westmead Hospital, Sydney, NSW, Australia; Sydney Medical School, University of Sydney, Sydney, NSW, Australia.
authors.forename: Pramesh
authors.initials: P
authors.lastname: Kovoor
authors.affiliation: Cardiology Department, Westmead Hospital, Sydney, NSW, Australia; Sydney Medical School, University of Sydney, Sydney, NSW, Australia.
authors.forename: Aravinda
authors.initials: A
authors.lastname: Thiagalingam
mesh_terms: D017115:Catheter Ablation / Q000379:methods*; D006352:Heart Ventricles; D006801:Humans; D009206:Myocardium; D013997:Time Factors
keywords: Efficacy; Long duration ablation; Radiofrequency ablations; Safety; Transmural lesions