背景:当使用病变大小指数(LSI)指导导管消融时,目前还不清楚是什么力量的组合,接触力和时间将是最好的使用和什么LSI目标值的目标。本研究旨在通过使用组织阻抗下降作为病变形成的指标来识别期望的消融设置和LSI目标。
方法:连续患者,接受第一次左心房(LA)导管消融治疗心房颤动,纳入射频能量(RF)功率为20、30和40W的患者。组织阻抗,接触力(CF),在消融期间连续记录力时间积分(FTI)和LSI值,并在100Hz下采样。计算每个病变的平均CF和接触力变异性(CFV)。射频功率的影响,消融时间,评估了阻抗下降和LSI上的CF和CFV。
结果:共3258个病灶纳入分析。对于任何目标LSI值,使用更高的RF功率转化为逐渐更高的阻抗下降。当使用较低功率时,较低CF和较高CFV对阻抗下降的影响更相关。根据RF功率确定对应于最大阻抗降的目标LSI值,使用的平均CF和CFV。
结论:即使在LSI引导消融策略的背景下,使用更低或更高的功率可能会导致不同的病变大小。根据RF功率的组合,可能需要不同的LSI目标,用于消融的CF和CFV。纳入导管稳定性指标,比如CFV,在LSI公式中可以提高LSI对病变大小的预测价值。需要对临床结果进行研究以确认这些发现的临床相关性。
BACKGROUND: When using lesion size index (LSI) to guide catheter ablation, it is unclear what combination of power, contact force and time would be preferable to use and what LSI target value to aim for. This study aimed at identifying desirable ablation settings and LSI targets by using tissue impedance drop as indicator of lesion formation.
METHODS: Consecutive patients, undergoing their first left atrial (LA) catheter ablation for atrial fibrillation, with radiofrequency energy (RF) powers of 20, 30 and 40 W were enrolled. Tissue impedance, contact force (CF), Force Time Integral (FTI) and LSI values were continuously recorded during ablation and sampled at 100 Hz. Mean CF and Contact Force Variability (CFV) were calculated for every lesion. The effect of RF power, ablation time, CF and CFV on impedance drop and LSI were assessed.
RESULTS: A total of 3258 lesions were included in the analysis. For any target LSI value, use of higher RF powers translated into progressively higher impedance drops. The impact of lower CF and higher CFV on impedance drop was more relevant when using lower powers. Target LSI values corresponding to maximum impedance drop were identified depending on RF power, mean CF and CFV used.
CONCLUSIONS: Even in the context of an LSI-guided ablation strategy, use of lower or higher powers might lead to different lesion sizes. Different LSI targets might be needed depending on the combination of RF power, CF and CFV used for ablation. Incorporating indicators of catheter stability, like CFV, in the LSI formula could improve the predictive value of LSI for lesion size. Studies with clinical outcomes are required to confirm the clinical relevance of these findings.