Department of Electrophysiology, Clinica Montevergine, Mercogliano, Avellino, Italy.
Second Division of Cardiology, Cardiac-Thoracic-Vascular Department, New Santa Chiara Hospital, Azienda Ospedaliero Universitaria Pisana, Pisa, Italy.
J Cardiovasc Electrophysiol. 2021 Jun;32(6):1540-1548. doi: 10.1111/jce.15041. Epub 2021 May 3.
Highly localized impedance (LI) measurements during atrial fibrillation (AF) ablation have recently emerged as a viable real-time indicator of tissue characteristics and durability of the lesions created. We report the outcomes of acute and long-term clinical evaluation of the new DirectSense algorithm in AF ablation.
Consecutive patients undergoing AF ablation were included in the CHARISMA registry. RF delivery was guided by the DirectSense algorithm, which records the magnitude and time-course of the impedance drop. The ablation endpoint was pulmonary vein isolation (PVI), as assessed by the entrance and exit block.
3556 point-by-point first-pass RF applications of >10 s duration were analyzed in 153 patients (mean age=59 ± 10 years, 70% men, 61% paroxysmal AF, 39% persistent AF). The mean baseline LI was 105 ± 15 Ω before ablation and 92 ± 12 Ω after ablation (p < .0001). Both absolute drops in LI and the time to LI drop (LI drop/τ) were greater at successful ablation sites (n = 3122, 88%) than at ineffective ablation sites (n = 434, 12%) (14 ± 8 Ω vs 6 ± 4 Ω, p < .0001 for LI; 0.73 [0.41-1.25] Ω/s vs. 0.35[0.22-0.59 Ω/s, p < .0001 for LI drop/τ). No major complications occurred during or after the procedures. All PVs had been successfully isolated. During a mean follow-up of 366 ± 130 days, 18 patients (11.8%) suffered an AF/atrial tachycardia recurrence after the 90-day blanking period.
The magnitude and time-course of the LI drop during RF delivery were associated with effective lesion formation. This ablation strategy for PVI guided by LI technology proved safe and effective and resulted in a very low rate of AF recurrence over 1-year follow-up.
在心房颤动（AF）消融过程中，高度局部化的阻抗（LI）测量最近已成为组织特性和消融损伤耐久性的可行实时指标。我们报告了新的 DirectSense 算法在 AF 消融中的急性和长期临床评估结果。
连续纳入接受 AF 消融的患者，纳入 CHARISMA 登记处。射频能量输送由 DirectSense 算法指导，该算法记录阻抗下降的幅度和时间过程。消融终点是肺静脉隔离（PVI），通过入口和出口阻滞进行评估。
在 153 例患者中，共分析了 3556 次 >10s 的单点首次通过 RF 应用（平均年龄为 59±10 岁，70%为男性，61%为阵发性 AF，39%为持续性 AF）。消融前的平均基础 LI 为 105±15Ω，消融后为 92±12Ω（p<0.0001）。在成功消融部位（n=3122，88%）和无效消融部位（n=434，12%），LI 的绝对值下降和 LI 下降时间（LI 下降/τ）均较大（14±8Ω比 6±4Ω，p<0.0001），LI 下降/τ 为 0.73[0.41-1.25]Ω/s 比 0.35[0.22-0.59]Ω/s，p<0.0001）。手术过程中和手术后均未发生重大并发症。所有肺静脉均成功隔离。在平均 366±130 天的随访期间，在 90 天空白期后，18 例患者（11.8%）出现 AF/房性心动过速复发。
RF 输送过程中 LI 下降的幅度和时间过程与有效损伤形成有关。这种基于 LI 技术的 PVI 消融策略既安全又有效，在 1 年随访中，AF 复发率非常低。
