Temperature-Controlled Radiofrequency Ablation Using Irrigated Catheters: Maximizing Ventricular Lesion Dimensions While Reducing Steam-Pop Formation

JACC Clin Electrophysiol. 2020 Jan;6(1):83-93. doi: 10.1016/j.jacep.2019.08.015. Epub 2019 Oct 30.

Abstract

Objectives: The goal of this study was to examine the safety and efficacy of radiofrequency ablation (RFA) with irrigated catheters operated in a temperature-controlled mode for ventricular ablation.

Background: Techniques to increase RFA dimensions are associated with higher risk for steam-pops. A novel irrigated catheter with circumferential thermocouples embedded in its ablation surface provides real-time surface temperature data. This study hypothesized that RFA operated in a temperature-controlled mode may allow maximizing lesion dimensions while reducing the occurrence of steam-pops.

Methods: RFA with an irrigated catheter incorporating surface thermocouples was examined in 6 swine thigh muscle preparations and 15 beating ventricles at higher (50 W/60 s, Tmax50oC) and lower (50 W/60 s, Tmax45oC) temperature limits. Biophysical properties, lesion dimensions, and steam-pop occurrence were compared versus RFA with a standard catheter operated in power-control mode at higher (50 W/60 s) and lower (40W/60 s) power, and additionally at high power with half-normal saline (50 W/60 s).

Results: In the thigh muscle preparation, lesion depth and width were similar between all groups (p = 0.90 and p = 0.17, respectively). Steam-pops were most frequent with power-controlled ablation at 50 W/60 s (82%) and least frequent with temperature-controlled ablation at 50 W/60 s, Tmax45oC (0%; p < 0.001). In the beating ventricle, lesion depth was comparable between all RFA settings (p = 0.09). Steam-pops were most frequent using power-controlled ablation at 50 W/60 s (37%) and least frequent with temperature-controlled ablation at 50 W/60 s, Tmax45oC (7%; p < 0.001). Half-normal saline had no incremental effect on lesion dimensions at 50 W in either the thigh muscle or the beating heart.

Conclusions: RFA using a novel irrigated catheter with surface thermocouples operated in a temperature-controlled mode can maximize lesion dimensions while reducing the risk for steam-pops.

Keywords: catheter ablation; electrophysiology; radiofrequency; ventricular ablation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Catheter Ablation* / adverse effects
  • Catheter Ablation* / instrumentation
  • Catheter Ablation* / methods
  • Catheter Ablation* / standards
  • Catheters*
  • Equipment Design
  • Heart Ventricles / pathology
  • Heart Ventricles / surgery*
  • Swine
  • Temperature
  • Therapeutic Irrigation / instrumentation*