Superiority of the Combination of Input and Output Parameters to the Single Parameter for Lesion Size Estimation

Hidehiro Iwakawa, Masateru Takigawa, Junji Yamaguchi, Claire A. Martin, Masahiko Goya, Tasuku Yamamoto, Miki Amemiya, Takashi Ikenouchi, Miho Negishi, Iwanari Kawamura, Kentaro Goto, Takatoshi Shigeta, Takuro Nishimura, Tomomasa Takamiya, Susumu Tao, Shinsuke Miyazaki, Hiroyuki Watanabe, Tetsuo Sasano

Research output: Contribution to journalArticlepeer-review

1 Scopus citations


Background: For lesion size prediction, each input parameter, including ablation energy (AE), and output parameter, such as impedance, is individually used. We hypothesize that using both parameters simultaneously may be more optimal. Methods and Results: Radiofrequency applications at a range of power (30–50W), contact force (10g and 20g), duration (10–60s), and catheter orientation with normal saline (NS)- or half-normal saline (HNS)-irrigation were performed in excised porcine hearts. The correlations, with lesion size of AE, absolute impedance drop (∆Imp-drop), relative impedance drop (%Imp-drop), and AE*%Imp-drop were examined. Lesion size was analyzed in 283 of 288 lesions (NS-irrigation, n=142; HNS-irrigation, n=141) without steam pops. AE*%Imp-drop consistently showed the strongest correlations with lesion maximum depth (NS-irrigation, ρ=0.91; HNS-irrigation, ρ=0.94), surface area (NS-irrigation, ρ=0.87; HNS-irrigation, ρ=0.86), and volume (NS-irrigation, ρ=0.94; HNS-irrigation, ρ=0.94) compared with the other parameters. Moreover, compared with AE alone, AE*%Imp-drop significantly improved the strength of correlation with lesion maximum depth (AE vs. AE*%Imp-drop, ρ=0.83 vs. 0.91, P<0.01), surface area (ρ=0.73 vs. 0.87, P<0.01), and volume (ρ=0.84 vs. 0.94, P<0.01) with NS-irrigation. This tendency was also observed with HNS-irrigation. Parallel catheter orientation showed a better correlation with lesion depth and volume using ∆Imp-drop, %Imp-drop, and AE*%Imp-drop than perpendicular orientation. Conclusions: The combination of input and output parameters is more optimal than each single parameter for lesion prediction.

Original languageEnglish
Pages (from-to)1757-1764
Number of pages8
JournalCirculation Journal
Issue number12
StatePublished - 2023
Externally publishedYes


  • Catheter ablation
  • Energy
  • Impedance
  • Lesion
  • Radiofrequency


Dive into the research topics of 'Superiority of the Combination of Input and Output Parameters to the Single Parameter for Lesion Size Estimation'. Together they form a unique fingerprint.

Cite this