Shimeno Kenji, Matsumoto Naoki, Tamura Shota, Matsuo Masanori, Hayashi Yusuke, Abe Yukio, Fukuda Daiju
Department of Cardiology, Osaka City General Hospital, Osaka, Japan.
Department of Cardiology, Osaka City General Hospital, Osaka, Japan.
Heart Rhythm. 2025 May;22(5):1289-1297. doi: 10.1016/j.hrthm.2024.08.039. Epub 2024 Aug 22.
Although output-dependent QRS transition is a specific indicator that confirms left bundle branch (LBB) capture during left bundle branch area pacing (LBBAP), its durability remains unclear.
The purpose of this study was to evaluate the presence of output-dependent QRS transition and capture thresholds of the LBB and left ventricular septal myocardium immediately and up to 1 year after the LBBAP procedure.
We enrolled 129 patients with successful LBBAP who were available for 1-year follow-up postoperatively. Threshold testing was performed immediately after LBBAP on postoperative day 0 (POD-0) and after 3 days (POD-3), 6 months (POD-180), and 1 year (POD-360).
Output-dependent QRS transition persisted in 64 patients (88%) on POD-360, from among the 73 patients with output-dependent QRS transition on POD-0. In contrast, 55 of 56 patients without QRS transition on POD-0 (98%) did not exhibit QRS transition thereafter. LBB thresholds were slightly elevated on POD-360, albeit without statistical significance, compared with those on POD-0 (1.22 ± 1.00 V vs 1.43 ± 1.29 V at 0.4 ms; P = .26). The LBB thresholds increased by ≥1.5 V in 7 patients (11%). However, in 93% of patients with an LBB threshold of ≤2.5 V on POD-0, LBB capture was maintained at 2.5 V on POD-360. Left ventricular septal thresholds were similar on POD-0 and POD-360 (0.81 ± 0.36 V vs 0.83 ± 0.24 V; P > .99) and did not increase by ≥1.5 V in any patient.
Output-dependent QRS transitions were highly reproducible after implantation. Furthermore, LBB thresholds remained stable in most cases during the first postoperative year.
尽管输出依赖型QRS波群转变是在左束支区域起搏（LBBAP）期间确认左束支（LBB）夺获的一项特异性指标，但其持久性仍不明确。
本研究旨在评估LBBAP术后即刻以及术后1年内输出依赖型QRS波群转变的存在情况以及LBB和左心室间隔心肌的夺获阈值。
我们纳入了129例LBBAP成功且术后可进行1年随访的患者。在术后第0天（POD-0）、3天（POD-3）、6个月（POD-180）和1年（POD-360）进行LBBAP后即刻进行阈值测试。
在POD-0时出现输出依赖型QRS波群转变的73例患者中，64例（88%）在POD-360时仍存在输出依赖型QRS波群转变。相比之下，在POD-0时无QRS波群转变的56例患者中有55例（98%）此后未出现QRS波群转变。与POD-0时相比，POD-360时LBB阈值略有升高，尽管无统计学意义（在0.4 ms时，分别为1.22±1.00 V和1.43±1.29 V；P = 0.26）。7例患者（11%）的LBB阈值升高≥1.5 V。然而，在POD-0时LBB阈值≤2.5 V的患者中，93%在POD-360时LBB夺获维持在2.5 V。POD-0和POD-360时左心室间隔阈值相似（分别为0.81±0.36 V和0.83±0.24 V；P＞0.99），且在任何患者中均未升高≥1.5 V。
植入后输出依赖型QRS波群转变具有高度可重复性。此外，在术后第一年的大多数情况下，LBB阈值保持稳定。
