title: Morphological and thermodynamic comparison of the lesions created by 4 open-irrigated catheters in 2 experimental models.
abstract: BACKGROUND
  New generation open-irrigated catheters aim to improve irrigation efficiency. This may change lesion patterns, challenging operators. Indeed, safety issues have recently arisen. We aimed to experimentally assess 4 open-irrigated catheters, comparing lesion size, safety, and heat transfer.
  
  
  METHODS
  The thigh lesion model was employed in 6 anesthetized pigs to assess the morphology of perpendicular and tangential lesions (n = 140) created by the newer catheters ThermoCool® SF, CoolFlex™, and Blazer™ Open-Irrigated, and the standard ThermoCool®, at a constant power of 30 W (60 seconds). To evaluate the propensity for deep-tissue overheating, a set of 120 applications were performed at 50 W (180 seconds) comparing pop rates. Thermal assessment of the lesion generation process (20 W, 60 seconds, n = 32) was performed with an infrared camera on bovine ventricular tissue.
  
  
  RESULTS
  At 30 W, the newer catheters showed lower temperature readings compared with the ThermoCool®. No major efficacy or safety differences were found at tangential applications; however, at perpendicular applications: (1) the SF at 17 mL/min better preserved the superficial layers and focused its maximum thermal effect deeper, but at recommended flow rates (8 mL/min) it generated the largest superficial lesions; (2) CoolFlex™ created smaller lesions than SF and readily induced steam pops at 50 W without temperature control; and (3) no major differences were found comparing Blazer™ Open-Irrigated and ThermoCool®.
  
  
  CONCLUSIONS
  The lower temperature readings in the newer catheters make them more prone to deliver the maximum programmed power. Under experimental conditions, the SF catheter focuses its maximum effect deeper and the CoolFlex™ can be more prone to induce steam pops at high power settings.
authors.affiliation: Optical and Thermal Mapping Laboratory, Arrhythmia Unit, Cardiovascular Institute, IdISSC, Hospital Clínico San Carlos, Madrid, Spain; Arrhythmia Unit, Cardiology Department, Hospital Ramón y Cajal, Madrid, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Moreno
authors.forename: Jorge G
authors.initials: JG
authors.lastname: Quintanilla
authors.forename: Roberto
authors.initials: R
authors.lastname: Molina-Morúa
authors.forename: María Jesús
authors.initials: MJ
authors.lastname: García-Torrent
authors.forename: María José
authors.initials: MJ
authors.lastname: Angulo-Hernández
authors.forename: Carolina
authors.initials: C
authors.lastname: Curiel-Llamazares
authors.forename: Julio
authors.initials: J
authors.lastname: Ramiro-Bargueño
authors.forename: Pablo
authors.initials: P
authors.lastname: González
authors.forename: Antonio J
authors.initials: AJ
authors.lastname: Caamaño
authors.forename: Nicasio
authors.initials: N
authors.lastname: Pérez-Castellano
authors.forename: José Luis
authors.initials: JL
authors.lastname: Rojo-Álvarez
authors.forename: Carlos
authors.initials: C
authors.lastname: Macaya
authors.forename: Julián
authors.initials: J
authors.lastname: Pérez-Villacastín
mesh_terms: D000818:Animals; D001831:Body Temperature / Q000502:physiology*; D062906:Cardiac Catheters; D006348:Cardiac Surgical Procedures / Q000295:instrumentation* / Q000379:methods; D017115:Catheter Ablation / Q000295:instrumentation* / Q000379:methods; D004735:Energy Transfer; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005260:Female; D006321:Heart / Q000502:physiology*; D013552:Swine; D007507:Therapeutic Irrigation / Q000295:instrumentation* / Q000379:methods; D016896:Treatment Outcome
keywords: arrhythmia; catheter ablation; lesion; radiofrequency; ventricular tachycardia