Background

The time-to-isolation (TTI) may be a physiological predictor of durable isolations, and TTI-guided dosing strategies are widely performed in cryoballoon ablation. We sought to investigate the impact of the order of targeting the pulmonary veins (PVs) on the TTI values of left ipsilateral PVs.

Methods

This study included 144 atrial fibrillation patients who underwent PV isolations using 28-mm fourth-generation cryoballoons. In 101 patients, the left superior PV (LSPV) was targeted and followed by the left inferior PV (LIPV) (group 1), and the LIPV was targeted and followed by the LSPV in the remaining 43 (group 2).

Results

The total LSPV and LIPV freeze durations were 193 ± 60 and 171 ± 40 s, respectively. Real-time PV isolation monitoring was capable in 137 (95.1%) LSPVs and 119 (82.6%) LIPVs and in 112 (77.8%) patients (78 in group 1 and 34 in group 2) in both LSPVs and LIPVs. Among them, the LSPV TTI was significantly longer in group 1 than that in group 2 (54.8 ± 32.1 vs. 34.1 ± 17.3 s, p < 0.0001), while the LIPV TTI was significantly shorter in group 1 than that in group 2 (23.7 ± 11.8 vs. 39.2 ± 19.4 s, p < 0.0001). The ΔTTI ((TTI in LSPV)-(TTI in LIPV)) was significantly greater in group 1 than that in group 2 (31.1 ± 31.4 vs. − 5.0 ± 25.9 s, p < 0.0001). In 5 patients (3 in group 1 and 2 in group 2), initially targeted left PVs were not isolated despite complete vein occlusions, while they were by subsequent applications at the other ipsilateral PVs.

Conclusions

In CB ablation, the order of targeting PVs highly influenced the TTI of the left PVs owing to the presence of electrical connections between left ipsilateral PVs.

中文翻译：

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左同侧肺静脉之间的电连接对冷冻球囊消融中的隔离时间值的影响

背景

隔离时间 (TTI) 可能是持久隔离的生理预测指标，并且 TTI 指导的给药策略在冷冻球囊消融中广泛使用。我们试图研究靶向肺静脉 (PV) 的顺序对左侧同侧 PV TTI 值的影响。

方法

这项研究包括 144 名使用 28 毫米第四代冷冻球囊进行 PV 隔离的心房颤动患者。在 101 名患者中，以左上 PV (LSPV) 为目标，随后是左下 PV (LIPV)（第 1 组），其余 43 名患者以 LIPV 为目标，随后为 LSPV（第 2 组）。

结果

LSPV 和 LIPV 的总冻结时间分别为 193 ± 60 和 171 ± 40 s。在 LSPV 和 LIPV 中，137 名 (95.1%) LSPV 和 119 名 (82.6%) LIPV 和 112 名 (77.8%) 患者（第 1 组 78 名和第 2 组 34 名）患者能够进行实时 PV 隔离监测。其中，第 1 组的 LSPV TTI 显着长于第 2 组（54.8 ± 32.1 vs. 34.1 ± 17.3 s，p  < 0.0001），而第 1 组的 LIPV TTI 显着短于第 2 组（23.7 ± 11.8 与 39.2 ± 19.4 秒，p  < 0.0001）。第 1 组的 ΔTTI ((LSPV 中的 TTI)-(LIPV 中的 TTI)) 显着高于第 2 组 (31.1 ± 31.4 vs. - 5.0 ± 25.9 s, p < 0.0001)。在 5 名患者（第 1 组中的 3 名和第 2 组中的 2 名患者）中，尽管静脉完全闭塞，但最初靶向的左侧 PV 并未被分离，而随后在其他同侧 PV 处应用。

结论

在 CB 消融中，由于左侧同侧 PV 之间存在电连接，靶向 PV 的顺序对左侧 PV 的 TTI 有很大影响。