J Cardiovasc Electrophysiol. 2022 Nov 20. doi: 10.1111/jce.15752. Online ahead of print.
ABSTRACT
INTRODUCTION: Intramural or epicardial locations of the arrhythmogenic substrate are regarded as one of the main reasons for radiofrequency (RF) catheter ablation failure. This study aims to conduct a comprehensive analysis of various factors including baseline impedance, irrigant and electrode configuration at similar ablation index value.
METHODS: In 12 ex vivo swine hearts, radiofrequency ablation was performed at a target AI value of 500 and a multistep impedance load (100-180Ω) in 4 settings: (1) conventional unipolar configuration with an irrigant of NS; (2) conventional unipolar configuration with an irrigant of HNS; (3) bipolar configuration with an irrigant of NS.; (4) sequential unipolar configuration with an irrigant of NS. The relationships between lesion dimensions and above factors were examined.
RESULTS: Baseline impedance had a strong negative linear correlation with lesion dimensions at a certain AI. The correlation coefficient between baseline impedance and depth, width, and volume were R =-0.890, R =-0.755 and R =-0.813, respectively (P<0.01). There were 10 (total: 10/100, 10%; bipolar: 10/25, 40%) transmural lesions during the whole procedure. Bipolar ablation resulted in significantly deeper lesion than other electrode configurations. Other comparisons in our experiment did not achieve statistical significance.
CONCLUSION: There is a strong negative linear correlation between baseline impedance and lesion dimensions at a certain AI value. Baseline impedance has an influence on the overall lesion dimensions among irrigated fluid and ablation configurations. Over a threshold impedance of 150Ω, the predictive accuracy of AI can be compromised. This article is protected by copyright. All rights reserved.
PMID:36403284 | DOI:10.1111/jce.15752
