Embedded thermal profiles during ventricular RF ablation were associated with the greatest impedance falls and the highest incidence of steam pops compared to other profiles (8.6% vs 1.3%; P<0.001).
Observational (n=100)
Do electrode thermal profiles correlate with catheter orientation, impedance fall, and steam pops during ventricular RF ablation?
Electrode thermal profiles during ventricular RF ablation provide complementary information to force vector and impedance, helping identify embedded catheter positions that are at high risk for steam pops.
Absolute Event Rate: 8.6% vs 1.3%
p-value: p=<0.001
BACKGROUND: Electrode-tissue contact and orientation influence radiofrequency (RF) ablation heating, lesion size, and steam pops, and is not easily assessed. A catheter with 6 distal electrode temperature sensors provides thermal profiles that may help clarify electrode-tissue interactions. OBJECTIVES: The aim of this study was to evaluate the relationships between thermal profiles, catheter orientation, impedance fall, steam pops, and discordant temperature-impedance changes during ventricular RF ablation. METHODS: We analyzed 2,085 RF applications in 100 patients, titrating power to a maximum temperature 10 Ω. Stable thermal profiles were classified as embedded, central, or peripheral. Catheter orientation from the force vector was classified as perpendicular, oblique, or parallel. RESULTS: The thermal profile aligned with the force vector at 60.9% of stable sites, with 72.1% of peripheral profiles being oblique/parallel and 80.4% of central profiles being perpendicular. Impedance fall was discordant with temperature at 890 (42.7%) sites. Catheter orientation and thermal profiles differed for low temperature-high impedance fall, compared with high temperature-low impedance fall discordant sites (P < 0.001). An embedded thermal profile (all sensors ≥45 °C) most often occurred with perpendicular or oblique orientations, had the greatest impedance falls, and had the highest incidence of steam pops (8.6% vs 1.3%; P < 0.001). No steam pops occurred with impedance falls <14 Ω or maximum temperature <45.8 °C, or when impedance fall and temperature were discordant. CONCLUSIONS: Electrode thermal profiles provide information complementary to force vector and impedance, reflecting electrode-tissue interactions that are also related to discrepancies in impedance fall and temperature during RF ablation. They can potentially help optimize RF ablation lesion size while avoiding steam pops.
Togashi et al. (Sat,) conducted a observational in Ventricular arrhythmias requiring RF ablation (n=100). Ventricular radiofrequency ablation with 6-sensor temperature catheter vs. Other thermal profiles was evaluated on Incidence of steam pops (p=<0.001). Embedded thermal profiles during ventricular RF ablation were associated with the greatest impedance falls and the highest incidence of steam pops compared to other profiles (8.6% vs 1.3%; P<0.001).