Cardiology Unit, 'Card. G. Panico' Hospital, Via S. Pio X, 4, 73039 Tricase, LE, Italy.
Division of Cardiology, University of Eastern Piedmont, Maggiore della Carità Hospital, Corso Mazzini, 18, 28100 Novara, Italy.
Europace. 2018 May 1;20(5):859-866. doi: 10.1093/europace/eux015.
Closed-loop stimulation (CLS) seemed promising in preventing the recurrence of vasovagal syncope (VVS) in patients with a cardioinhibitory response to head-up tilt test (HUTT) compared with conventional pacing. We hypothesized that the better results of this algorithm are due to its quick reaction in high-rate pacing delivered in the early phase of vasovagal reflex, which increase the cardiac output and the blood pressure preventing loss of consciousness.
This prospective, randomized, single-blind, multicentre study was designed as an intra-patient comparison and enrolled 30 patients (age 62.2 ± 13.5 years, males 60.0%) with cardioinhibitory VVS, carrying a dual-chamber pacemaker incorporating CLS algorithm. Two HUTTs were performed one week apart: one during DDD-CLS 60-130/min pacing and the other during DDD 60/min pacing; patients were randomly and blindly assigned to two groups: in one the first HUTT was performed in DDD-CLS (n = 15), in the other in DDD (n = 15). Occurrence of syncope and haemodynamic variations induced by HUTT was recorded during the tests. Compared with DDD, DDD-CLS significantly reduced the occurrence of syncope induced by HUTT (30.0% vs. 76.7%; P < 0.001). In the patients who had syncope in both DDD and DDD-CLS mode, DDD-CLS significantly delayed the onset of syncope during HUTT (from 20.8 ± 3.9 to 24.8 ± 0.9 min; P = 0.032). The maximum fall in systolic blood pressure recorded during HUTT was significantly lower in DDD-CLS compared with DDD (43.2 ± 30.3 vs. 65.1 ± 25.8 mmHg; P = 0.004).
In patients with cardioinhibitory VVS, CLS reduces the occurrence of syncope induced by HUTT, compared with DDD pacing. When CLS is not able to abort the vasovagal reflex, it seems to delay the onset of syncope.
与传统起搏相比，闭环刺激（CLS）似乎在预防对倾斜试验（HUTT）呈心脏抑制反应的血管迷走性晕厥（VVS）患者的晕厥复发方面具有优势。我们假设，该算法的更好结果归因于其在血管迷走反射早期快速反应，以增加心输出量和血压，防止意识丧失。
这项前瞻性、随机、单盲、多中心研究设计为患者内比较，纳入了 30 名（年龄 62.2±13.5 岁，男性 60.0%）患有心脏抑制性 VVS 的患者，这些患者携带具有 CLS 算法的双腔起搏器。一周内进行两次 HUTT：一次在 DDD-CLS 60-130/min 起搏下进行，另一次在 DDD 60/min 起搏下进行；患者被随机和盲目分配到两组：一组在 DDD-CLS 下进行第一次 HUTT（n=15），另一组在 DDD 下进行（n=15）。记录测试过程中 HUTT 引起的晕厥和血液动力学变化。与 DDD 相比，DDD-CLS 显著降低了 HUTT 引起的晕厥发生率（30.0%比 76.7%；P<0.001）。在 DDD 和 DDD-CLS 模式下均发生晕厥的患者中，DDD-CLS 显著延迟了 HUTT 期间晕厥的发作（从 20.8±3.9 分钟到 24.8±0.9 分钟；P=0.032）。与 DDD 相比，DDD-CLS 记录的 HUTT 期间收缩压最大下降幅度显著降低（43.2±30.3 比 65.1±25.8mmHg；P=0.004）。
在心脏抑制性 VVS 患者中，与 DDD 起搏相比，CLS 可降低 HUTT 引起的晕厥发生率。当 CLS 不能中止血管迷走反射时，它似乎会延迟晕厥的发作。
