title: Ablation efficacy and electrical morphology of a novel 18-hole open-irrigated catheter.
abstract: BACKGROUND
  The 6-hole open-irrigated catheter (SHOI) is increasingly used in radiofrequency (RF) ablation of arrhythmias. However, deep transmural lesions are not always achieved, and volume overload caused by irrigated ablation is another problem that should be concerned. The purpose of this study was to analyze and compare the ablation effect and electrical morphology between a novel 18-hole open-irrigated catheter (EHOI) and SHOI.
  
  
  RESULTS
  The heart was exposed through a median sternotomy in 12 anesthetized dogs, and the chest cavity was filled with heparinized saline. Bipolar contact pericardial electrograms of both catheters were recorded. Lesions were created under all permutations of the following conditions: RF energy 30 and 40 W for 60 seconds, contact force at 10, 30, and 50 g, electrode orientation horizontal to the tissue, irrigation rate 10 mL/min for EHOI and 17 mL/min for SHOI. The EHOI created deeper lesions than SHOI (5.77 ± 1.37 mm vs 4.98 ± 1.22 mm at power of 30 W, P < 0.05; 7.16 ± 1.15 mm vs 6.02 ± 1.04 mm at power of 40 W, P < 0.01), and there was a trend of larger lesion volume for EHOI (312 ± 141 mm(3) vs 259 ± 108 mm(3) at power of 30 W, 536 ± 200 mm(3) vs 451 ± 180 mm(3) at power of 40 W, P > 0.05). No significant difference in electrogram morphology between 2 catheters was detected.
  
  
  CONCLUSIONS
  The mapping electrograms of EHOI and SHOI were not significantly different. Compared with SHOI, EHOI more effectively produced deeper lesions at a lower rate of irrigation perfusion.
authors.affiliation: Cardiovascular Institute and FuWai Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China.
authors.forename: Xiao-Hui
authors.initials: XH
authors.lastname: Ning
authors.forename: Min
authors.initials: M
authors.lastname: Tang
authors.forename: Yue
authors.initials: Y
authors.lastname: Tang
authors.forename: Yi
authors.initials: Y
authors.lastname: Tian
authors.forename: Shu
authors.initials: S
authors.lastname: Zhang
mesh_terms: D000818:Animals; D017115:Catheter Ablation / Q000295:instrumentation* / Q000379:methods*; D004285:Dogs; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006329:Heart Conduction System / Q000503:physiopathology* / Q000601:surgery*; D007507:Therapeutic Irrigation / Q000295:instrumentation* / Q000379:methods*