Neuraxial Modulation for Refractory Ventricular Arrhythmias: Value of Thoracic Epidural Anesthesia and Surgical Left Cardiac Sympathetic Denervation
椎管内调制治疗难治性室性心律失常：胸段硬膜外麻醉和手术左心交感神经去神经术的价值

We reviewed data from 14 patients from 3 medical centers between July 2005 and September 2009 who underwent neuraxial modulation with TEA or LCSD for the management of refractory ventricular arrhythmias. These patients were a subset of 154 patients who presented with “refractory” ventricular arrhythmias (over the 51-month period) to the centers involved in the present report. Stepwise arrhythmia management (with ablation in many cases) controlled arrhythmias for the vast majority; the patients who were selected for neuraxial modulation were refractory to all available treatments and were too unstable for any further treatment without arrhythmia control. We included 1 patient in the present series who was included in a previous report from our institution.³ Review of patient data was approved by the local institutional review boards of each of the medical centers.
我们回顾了 2005 年 7 月至 2009 年 9 月期间来自 3 个医疗中心的 14 名患者的数据，这些患者接受了 TEA 或 LCSD 椎管内调节治疗难治性室性心律失常。这些患者是向本报告涉及的中心就诊的 154 名患者中的一部分，他们患有“难治性”室性心律失常（超过 51 个月）。逐步的心律失常管理（在许多情况下采用消融术）控制了绝大多数的心律失常；被选择进行椎管内调节的患者对所有可用的治疗均无效，并且在没有心律失常控制的情况下无法进行任何进一步的治疗。我们在本系列中纳入了 1 名患者，该患者已纳入我们机构之前的报告中。 ³ 患者数据的审查得到了每个医疗中心当地机构审查委员会的批准。

The type, cause, and treatment of ventricular arrhythmias, neuraxial modulation used, immediate outcomes, procedural complications, and follow-up were noted in all patients. VT storm was defined as 3 or more sustained episodes of VT within a 24-hour period, each of which required termination by intervention.¹⁹ Incessant VT was defined as continuous sustained VT that recurred promptly despite repeated intervention for termination over several hours.¹⁹ When available, telemetry tracings and implantable cardioverter-defibrillator interrogation details were reviewed for each patient.
所有患者均记录了室性心律失常的类型、原因和治疗、使用的椎管内调节、即时结果、手术并发症和随访情况。 VT 风暴被定义为 24 小时内 3 次或以上持续的 VT 发作，每次都需要通过干预终止。 ¹⁹ 持续性 VT 定义为持续性 VT，尽管在数小时内反复干预终止，但仍迅速复发。 ¹⁹ 在可用的情况下，对每位患者的遥测追踪和植入式心脏复律除颤器询问详细信息进行了审查。

Ventricular arrhythmias were managed aggressively according to the standard clinical practice for management of ventricular arrhythmias at our centers. β-Blockers and antiarrhythmic drugs were given in sequence, devices were reprogrammed to minimize shocks, reversible causes (such as myocardial ischemia and electrolyte disturbances) were treated, deep sedation and intubation with induction of general anesthesia were considered, and catheter ablation was performed where feasible. When arrhythmias remained refractory despite these interventions, and when death was thought to be imminent, use of TEA or LCSD was considered to stabilize the patient before further interventions. The decision for TEA was individualized. If a surgeon who could perform emergent LCSD was not readily available or a patient was awaiting orthotopic heart transplant evaluation or catheter ablation, the patient underwent TEA. Otherwise, the patient underwent LCSD.
我们中心根据室性心律失常管理的标准临床实践积极管理室性心律失常。按顺序给予β受体阻滞剂和抗心律失常药物，对装置进行重新编程以尽量减少休克，治疗可逆性原因（例如心肌缺血和电解质紊乱），考虑深度镇静和插管全身麻醉诱导，并在以下情况下进行导管消融：可行的。尽管采取了这些干预措施，但心律失常仍然难以控制，并且认为死亡迫在眉睫时，可以考虑在进一步干预之前使用 TEA 或 LCSD 来稳定患者的病情。 TEA 的决定是因人而异的。如果无法找到能够进行紧急 LCSD 的外科医生，或者患者正在等待原位心脏移植评估或导管消融术，则患者会接受 TEA。否则，病人接受康乐及文化事务署(LCSD)治疗。

Hospitalizations, outpatient visits, and implantable cardioverter-defibrillator interrogation records were used to determine patients’ outcomes after their discharge from hospital.
住院、门诊和植入式心脏复律除颤器询问记录被用来确定患者出院后的结果。

Continuous variables are summarized with mean±SD or median and quartiles as appropriate. Exact 68% confidence intervals are provided for outcome percentages. Computations were performed with StatXact (Cytel Inc, Cambridge, Mass).
连续变量根据情况用平均值±SD 或中位数和四分位数进行总结。为结果百分比提供了精确的 68% 置信区间。使用 StatXact（Cytel Inc，剑桥，马萨诸塞州）进行计算。

Clinical parameters of the patients are shown in Table 1. The group consisted of 13 men and 1 woman, with an age range from 25 to 75 years (54.2±16.6 years). Twelve patients were in VT storm (4 were in incessant VT), and 2 experienced recurrent VT on maximal medical therapy despite having had 3 previous VT ablation procedures each. Four patients (29%) had polymorphic VT, and 10 patients (71%) had monomorphic VT. Among the 10 patients with monomorphic VT, 7 (70%) had more than 1 VT morphology; the mean±SD number of morphologies was 2.4±0.9. Nine (64%) of 14 patients had an ejection fraction ≤35%. One patient (patient 4) had active ischemia but had no targets for revascularization. The total number of therapies per patient before either procedure ranged from 5 to 202, with a median of 24 (25th and 75th percentile of 5 and 56). Twelve patients (86%) had an implantable cardioverter-defibrillator. Eleven patients (79%) had a history of VT, 8 (73%) of whom had previously undergone VT ablation.
患者临床参数见表1。该组包括13例男性和1例女性，年龄25至75岁（54.2±16.6岁）。 12 名患者处于室性心动过速风暴（4 名患者处于持续性室性心动过速），其中 2 名患者在接受最大程度的药物治疗后出现了复发性室性心动过速，尽管之前每人均接受过 3 次室性心动过速消融手术。 4 名患者 (29%) 患有多形性 VT，10 名患者 (71%) 患有单形性 VT。 10 例单形性 VT 患者中，7 例（70%）有 1 种以上 VT 形态；形态数的平均值±SD为2.4±0.9。 14 名患者中有 9 名 (64%) 射血分数≤35%。一名患者（患者 4）患有活动性缺血，但没有血运重建的目标。每位患者在任一手术前接受的治疗总数为 5 至 202 次，中位数为 24 次（第 25 和 75 个百分位分别为 5 和 56）。 12 名患者 (86%) 拥有植入式心脏复律除颤器。 11 名患者 (79%) 有 VT 病史，其中 8 名 (73%) 先前接受过 VT 消融术。

Treatment of VT and immediate response to neuraxial modulation are summarized in Table 2. β-Blockers were used in 12 of 14 patients but were contraindicated in 2 patients owing to cardiogenic shock and a history of severe bronchospasm. Antiarrhythmic drugs were used in all patients. Three patients were intubated to facilitate arrhythmia management.
表 2 总结了 VT 的治疗和对椎管内调节的即时反应。14 名患者中有 12 名使用了 β 受体阻滞剂，但 2 名患者因心源性休克和严重支气管痉挛病史而禁用。所有患者均使用抗心律失常药物。三名患者接受插管以促进心律失常管理。

Six patients underwent VT ablation before neuraxial modulation, whereas 4 patients were too unstable to undergo a procedure (Table 2). Multiple VT morphologies precluded ablation in 2 patients, and 1 patient had unmappable VT. An ablation procedure was contraindicated in 1 patient because of the presence of severe thrombocytopenia. No patient underwent intra-aortic balloon pump implantation or insertion of a ventricular assist device before neuraxial modulation.
6 名患者在椎管内调制前接受了 VT 消融，而 4 名患者由于太不稳定而无法接受手术（表 2）。 2 名患者因多种 VT 形态而无法进行消融，1 名患者的 VT 无法标测。 1 名患者因存在严重血小板减少症而禁忌进行消融手术。没有患者在椎管内调制之前接受主动脉内球囊泵植入或心室辅助装置插入。

Six of 8 patients who underwent TEA had a ≥80% reduction in arrhythmias; this included 3 of 3 patients with polymorphic VT and 3 of 5 with monomorphic VT (Table 3). The causes of the polymorphic VT were ischemic cardiomyopathy in 2 patients and arrhythmogenic right ventricular dysplasia in 1 patient. The causes of the monomorphic VT were ischemic cardiomyopathy in 2 patients and nonischemic cardiomyopathy in 1 patient. Of these 6 patients, 4 survived to discharge, 1 had TEA alone (and underwent urgent cardiac transplantation), and 3 had TEA followed by LCSD. One patient who did not respond to TEA survived to discharge.
接受 TEA 的 8 名患者中有 6 名心律失常减少了 80% 以上；其中包括 3 名多形性 VT 患者中的 3 名和 5 名单形性 VT 患者中的 3 名（表 3）。多形性室性心动过速的病因为2例缺血性心肌病和1例致心律失常性右心室发育不良。单形性室速的病因为缺血性心肌病 2 例，非缺血性心肌病 1 例。在这 6 名患者中，4 名存活出院，1 名仅接受 TEA（并接受紧急心脏移植），3 名先接受 TEA，然后接受 LCSD。一名对 TEA 无反应的患者幸存并出院。

Of the 9 patients who underwent LCSD, 5 had either a complete or partial response (Table 3). This included 1 patient with polymorphic VT due to arrhythmogenic right ventricular dysplasia and 4 patients with monomorphic VT due to ischemic cardiomyopathy, nonischemic cardiomyopathy, sarcoid cardiomyopathy, and arrhythmogenic right ventricular dysplasia (1 patient each). All 5 patients survived to discharge, as did 2 patients in whom no response to LCSD was seen.
在接受 LCSD 的 9 名患者中，5 名获得完全或部分缓解（表 3）。其中包括 1 名因致心律失常性右心室发育不良导致的多形性 VT 患者和 4 名因缺血性心肌病、非缺血性心肌病、肉瘤样心肌病和致心律失常性右心室发育不良导致的单形性 VT 患者（各 1 名患者）。所有 5 名患者均存活至出院，另外 2 名患者对康乐及文化事务署没有作出任何反应。

These observational data suggest that the use of TEA and LCSD can be beneficial for the management of refractory ventricular arrhythmias in patients with SHD. Both procedures were well tolerated, which allowed stabilization of patients before a catheter ablation procedure was performed or acted as a bridge to definitive therapy.
这些观察数据表明，TEA 和 LCSD 的使用有助于治疗 SHD 患者的难治性室性心律失常。这两种手术都具有良好的耐受性，这使得患者在进行导管消融手术之前能够保持稳定，或者作为最终治疗的桥梁。

TEA is a therapeutic option that selectively targets fibers that innervate the myocardium.²⁰ Its immediate onset of action can interrupt the vicious circle of recurrent shocks that lead to elevation of catecholamine levels that in turn potentiate further arrhythmias, and it may avert the need for intubation. TEA tends to have minimal effects on hemodynamic parameters, including heart rate, mean arterial pressure, cardiac index, and central venous pressure.²¹ TEA was well tolerated in all the patients in the present series.
TEA 是一种选择性针对支配心肌的纤维的治疗选择。 ²⁰ 其立即起效可以中断反复电击的恶性循环，从而导致儿茶酚胺水平升高，从而进一步加剧心律失常，并且可以避免插管的需要。 TEA 对血流动力学参数（包括心率、平均动脉压、心脏指数和中心静脉压）的影响往往很小。 ²¹ TEA 在本系列的所有患者中均具有良好的耐受性。

TEA has the potential to provide complete sympathetic blockade, blocking segments C8-T4. Although spinal segments T1–4 give rise to the majority of cardiac accelerator fibers, C8 can form part of the inferior cardiac sympathetic nerve. Therefore, TEA, by inhibiting fibers that are proximal to both the left and right stellate ganglia, could be more effective than LCSD (which is a unilateral intervention). TEA can be instituted at the bedside without specialized equipment. TEA was used as a bridge to more definitive therapy in 5 of 8 patients in this series. Application of local anesthetic to the epidural space results in almost immediate selective sympatholysis, which may be of particular benefit in patients with SHD, in whom the presence of scar may impede effective delivery of β-blockade to the myocardial substrate. However, the dose of TEA is difficult to titrate, because there are no markers that are easy to use, other than an assessment of its efficacy in arrhythmia control.
TEA 有可能提供完全的交感神经阻断，阻断 C8-T4 片段。尽管脊髓节段 T1-4 产生大部分心脏加速纤维，但 C8 可以形成心脏下交感神经的一部分。因此，TEA 通过抑制靠近左右星状神经节的纤维，可能比 LCSD（单侧干预）更有效。 TEA 可以在床边进行，无需专门设备。在该系列的 8 名患者中，有 5 名使用 TEA 作为更明确治疗的桥梁。在硬膜外腔应用局部麻醉剂几乎可以立即产生选择性交感神经松解，这对于 SHD 患者可能特别有益，因为在这些患者中，疤痕的存在可能会阻碍 β-阻滞剂有效输送至心肌基质。然而，TEA 的剂量很难滴定，因为除了评估其在心律失常控制方面的功效外，没有易于使用的标记物。

After LCSD, a 90% reduction in cardiac events has been shown in high-risk patients with long-QT syndrome.⁹ A reduced number of cardiac events was also seen in a cohort of patients with long-QT syndrome and catecholaminergic polymorphic VT who received LCSD for secondary prevention.¹¹ LCSD interrupts the major source of norepinephrine release in the heart. The antiarrhythmic effects of LCSD, although present to some extent immediately after denervation, become more complete with chronic denervation. This may be due in part to the massive neuraxial activation at the moment of surgical resection.²² By our definition of “no response,” we may have excluded some patients in whom transient benefit from LCSD was seen. LCSD involves a preganglionic denervation with removal of synapses, and therefore, neural regeneration does not occur. Furthermore, there is a partial reduction of the catecholamine content of the ventricle, which reduces postdenervation supersensitivity.²³
LCSD 治疗后，患有长 QT 综合征的高危患者的心脏事件减少了 90%。 ⁹ 在接受 LCSD 进行二级预防的长 QT 综合征和儿茶酚胺能多形性 VT 患者队列中，心脏事件数量也有所减少。 ¹¹ 康乐及文化事务署阻断了心脏中去甲肾上腺素释放的主要来源。 LCSD 的抗心律失常作用虽然在去神经支配后立即在一定程度上存在，但随着慢性去神经支配而变得更加完全。这可能部分是由于手术切除时大量的椎管内激活所致。 ²² 根据我们对“无反应”的定义，我们可能排除了一些从 LCSD 中短暂受益的患者。 LCSD 涉及节前去神经并去除突触，因此不会发生神经再生。此外，心室的儿茶酚胺含量部分减少，从而降低去神经后的超敏性。 ²³

LCSD is a more definitive treatment than TEA and has lasting effects. There is objective evidence of denervation after resection of the sympathetic chain, with histological confirmation of the presence of sympathetic chain and ganglia. Surgical LCSD requires general anesthesia and intubation, which alone may help control arrhythmias temporarily; however, hemodynamic instability may preclude this in the clinical setting. The safety and feasibility of a video-assisted thorascopic surgical LCSD has been reported previously in several small series.^10,11,13,24 More than half of the LCSD patients in the present series experienced benefit from the procedure; even in the no-response LCSD group, all but 1 patient had temporary arrhythmia resolution, which provided an opportunity to implement other therapeutic options. One patient in whom catheter ablation and TEA were contraindicated because of the presence of severe thrombocytopenia had complete resolution of ventricular arrhythmias after LCSD. Emergent LCSD may not be available in many centers; however, where available, it may be used to stabilize patients, to act as a bridge to ablation or surgical intervention, or potentially to reduce shock frequency when all other therapeutic options have been exhausted. Temporary LCSD block can also be used in this setting; however, repeated dosing and inability to use concurrent anticoagulation are limitations in the clinical setting.²⁵
LCSD 是比 TEA 更明确的治疗方法，并且具有持久的效果。有交感链切除后去神经支配的客观证据，并通过组织学证实交感链和神经节的存在。手术 LCSD 需要全身麻醉和插管，仅此一项就可以帮助暂时控制心律失常；然而，血流动力学不稳定可能会在临床环境中排除这一点。电视胸腔镜手术 LCSD 的安全性和可行性之前已在几个小型系列文章中报道过。 ^10,11,13,24 在本系列中，超过一半的康文署患者从手术中受益；即使在无反应的 LCSD 组中，除 1 名患者外，所有患者的心律失常均得到暂时缓解，这为实施其他治疗方案提供了机会。一名因存在严重血小板减少而禁忌导管消融和 TEA 的患者在 LCSD 后室性心律失常完全消失。许多中心可能不提供康乐及文化事务署紧急服务；然而，在可行的情况下，它可用于稳定患者，充当消融或手术干预的桥梁，或者在所有其他治疗选择均已用尽时潜在地降低电击频率。临时 LCSD 块也可用于此设置；然而，重复给药和无法同时使用抗凝药物是临床环境中的局限性。 ²⁵

In SHD, external triggers (including ischemia, reperfusion, autonomic state, and electrolyte disturbance) interact with a fixed substrate (such as prior myocardial infarct in ischemic heart disease or less discrete scarring or myocardial disarray in other forms of SHD) to precipitate and perpetuate an arrhythmia. Sympathetic hyperactivity is an important modulator of ventricular arrhythmias, including electrical storm.²⁶ The influence and relevance of sympathetic hyperactivity in each patient are variable and are dependent on the type, cause, and mechanism of the underlying arrhythmia and on the clinical scenario. In the present series, despite disparate causes, 80% of polymorphic VT and 58% of monomorphic VT cases responded to neuraxial modulation.
在 SHD 中，外部触发因素（包括缺血、再灌注、自主状态和电解质紊乱）与固定基质（例如缺血性心脏病中的既往心肌梗死或其他形式的 SHD 中不太离散的疤痕或心肌紊乱）相互作用，从而促成和永久化心律失常。交感神经亢进是室性心律失常（包括电风暴）的重要调节因素。 ²⁶ 交感神经过度活跃对每个患者的影响和相关性是可变的，并且取决于潜在心律失常的类型、原因和机制以及临床情况。在本系列中，尽管病因不同，但 80% 的多形性 VT 病例和 58% 的单形性 VT 病例对椎管内调节有反应。

There are several potential reasons for failure of TEA and LCSD in arrhythmia control: (1) A sympathetic trigger may not be responsible for initiation or perpetuation of the arrhythmia, and therefore, its elimination may not affect arrhythmia burden. (2) Sympathetic blockade secondary to TEA may be incomplete. The addition of autonomic nervous system blockade by simultaneous administration of propranolol, atropine, and hexamethonium during TEA has been shown to augment the effects of TEA on repolarization and effective refractory period in an animal model.⁶ (3) Denervation secondary to LCSD may also be incomplete; resection of the lower half of the left stellate ganglion to T4 has been suggested,⁷ but this level of denervation was not performed in 5 of the patients in the present cohort. (4) The nerve of Kuntz (an inconstant intrathoracic nerve that connects the first and second thoracic nerves, bypassing the sympathetic chain between the T2 ganglion and stellate ganglion)²⁷ should be sought out and divided if sympathectomy is to be complete. (5) Remaining sympathetic innervation via the right stellate ganglion (which contributes to cardiac sympathetic innervation to varying degrees) may also contribute to the failure of LCSD in controlling arrhythmias in some patients. These limitations of LCSD have also been reported in the long-QT syndrome population; LCSD was shown to reduce but not abolish sudden cardiac death in 2 large studies,^7,9 and in a small series,²⁸ LCSD proved inadequate for control of symptoms despite addition of β-blockade.
TEA 和 LCSD 在心律失常控制方面失败有几个潜在原因：（1）交感神经触发可能不是心律失常的引发或持续的原因，因此，其消除可能不会影响心律失常负担。 (2) TEA继发的交感神经阻滞可能不完全。在动物模型中，在 TEA 期间同时给予普萘洛尔、阿托品和六甲铵来增加自主神经系统阻滞已被证明可以增强 TEA 对复极和有效不应期的影响。 ⁶ (3) 康文署继发的去神经支配术也可能不完全；建议将左星状神经节下半部切除至 T4， ⁷ ，但本队列中有 5 名患者未进行这种水平的去神经术。 (4) Kuntz 神经（连接第一和第二胸神经的不稳定胸内神经，绕过 T2 神经节和星状神经节之间的交感链） ²⁷ ，如果要切除交感神经，则应找到并分开。是完整的。 (5) 通过右侧星状神经节的剩余交感神经支配（在不同程度上有助于心脏交感神经支配）也可能导致 LCSD 无法控制某些患者的心律失常。 LCSD 的这些局限性在长 QT 综合征人群中也有报道；两项大型研究 ^7,9 表明 LCSD 可以减少但不能消除心源性猝死，而在一项小系列研究中， ²⁸ LCSD 证明尽管添加了 β-阻滞剂，但仍不足以控制症状。

The present data strengthens the available data in the literature on the value of sympathetic blockade for the management of ventricular arrhythmias. The key strategies for management of VT storm include the following: (1) Early pharmacological sympathetic blockade; (2) antiarrhythmic drugs, especially amiodarone and lidocaine; (3) reprogramming of devices to minimize shocks; (4) management of reversible causes that are proarrhythmic, which include electrolyte disturbances, fluid overload, and ischemia; (5) catheter ablation of the clinical arrhythmia if patients can be transported safely to the laboratory; and (6) deep sedation or intubation with general anesthesia as an adjunct to sympathetic blockade in arrhythmia control, as well as for patient comfort. Of note, TEA can be instituted quickly and has the advantage of providing immediate effect while precipitants are addressed, cardiac transplant evaluation is performed, or surgery or assist device insertion is arranged, or when stabilization of the patient before ablation is required. TEA may also be used as a bridge to LCSD if this is not available emergently. LCSD provides long-lasting effects; it may be indicated if there are no reversible precipitants and no further surgical or ablative options exist, and it may be used as a bridge to nonurgent cardiac transplantation.
目前的数据强化了文献中有关交感神经阻滞治疗室性心律失常价值的现有数据。治疗室性心动过速风暴的关键策略包括：（1）早期药物交感神经阻滞； (2)抗心律失常药物，尤其是胺碘酮、利多卡因； (3) 对设备重新编程以尽量减少冲击； (4) 处理致心律失常的可逆原因，包括电解质紊乱、液体超负荷和缺血； (5)导管消融临床心律失常患者是否可以安全转运至实验室； (6) 深度镇静或全身麻醉插管，作为控制心律失常的交感神经阻滞的辅助手段，并让患者感到舒适。值得注意的是，TEA 可以快速启动，并且具有在处理诱发因素、进行心脏移植评估、安排手术或辅助装置插入、或者需要在消融前稳定患者时提供立竿见影效果的优点。如果紧急情况下无法使用，TEA 也可用作康乐及文化事务署的桥梁。康乐及文化事务署提供持久的影响；如果没有可逆的诱因并且不存在进一步的手术或消融选择，则可能表明它，并且它可以用作非紧急心脏移植的桥梁。

Because of the retrospective observational nature of the present study, some (unavoidable) limitations must be considered. Patients were not randomized; VT storms sometimes do subside spontaneously, and the contribution of such remissions to the study findings cannot be delineated clearly. However, patients were treated unsuccessfully with aggressive medical therapy and catheter ablation (where feasible) before undergoing either procedure. In addition to the small size of the study, the causes of ventricular arrhythmias in the present study population were diverse, and the value of autonomic blockade may vary in cardiomyopathies of different origins.
由于本研究的回顾性观察性质，必须考虑一些（不可避免的）局限性。患者没有被随机分组​​； VT 风暴有时确实会自发消退，并且这种缓解对研究结果的贡献无法清楚地描述。然而，在接受这两种手术之前，患者接受了积极的药物治疗和导管消融（如果可行），但没有成功。除了研究规模较小之外，目前研究人群中室性心律失常的原因多种多样，并且自主神经阻滞的价值在不同起源的心肌病中可能有所不同。

LCSD procedures were performed by several operators, and levels of denervation differed. The fact that only 4 patients in the present series had complete denervation may have adversely impacted the LCSD outcomes. Of the 8 TEA patients, 3 were already intubated before commencement of TEA infusion, which may have modified the effects of the TEA. Although all 3 patients had arrhythmias despite general anesthesia, the addition of TEA abolished arrhythmias in 2 of 3 patients, which suggests an added beneficial effect.
康乐及文化事务署的手术由多名操作员进行，去神经术的程度也各不相同。事实上，本系列中只有 4 名患者接受了完全去神经术，这可能对康乐及文化事务署的结果产生了不利影响。在 8 名 TEA 患者中，3 名患者在开始 TEA 输注之前已经插管，这可能改变了 TEA 的效果。尽管全身麻醉下，所有 3 名患者均出现心律失常，但添加 TEA 消除了 3 名患者中 2 名的心律失常，这表明有额外的有益效果。

There is also a referral bias in this study population, because all of the centers involved in the present study are specialized referral centers for catheter ablation of VT. Over the 51-month period of this study, 154 patients presented with refractory ventricular arrhythmias to the centers involved. Medical therapy (with ablation in many cases) controlled arrhythmias for the vast majority of these patients (140; 91%). Of the remaining 14 (9%) very-high-risk patients who underwent neuraxial modulation, 9 (64%) survived to hospital discharge. A 9% rate of nonresponse to conventional treatment for ventricular arrhythmias may be higher than would be expected in the general population of patients with VT.
本研究人群还存在转诊偏差，因为参与本研究的所有中心都是室性心动过速导管消融的专业转诊中心。在这项研究的 51 个月期间，154 名患者因难治性室性心律失常到相关中心就诊。药物治疗（许多情况下采用消融术）控制了绝大多数患者的心律失常（140；91%）。其余 14 名 (9%) 接受椎管内调节的极高危患者中，9 名 (64%) 存活至出院。室性心律失常常规治疗的无反应率为 9%，可能高于一般 VT 患者群体的预期。

Ventricular arrhythmias in patients with SHD typically tend to be macroreentrant; however, it is not known how often functional VTs due to triggered activity may play a role. Adrenergic modulation is thought to play a significant role in such cases of functional VT. Alteration in refractoriness and a reduction in ectopy/triggers may mechanistically account for the effect of either intervention. Myocardial refractoriness was not measured, and ectopy was not quantified before and after intervention. The present study does not allow examination of potential confounding factors such as prior episodes of VT storm, comorbidities, and pathogenesis.
SHD 患者的室性心律失常通常是大折返性的；然而，尚不清楚由触发活动引起的功能性 VT 发挥作用的频率。肾上腺素能调节被认为在此类功能性 VT 病例中发挥着重要作用。不应性的改变和异位/触发的减少可以从机械上解释任一干预措施的效果。未测量心肌不应性，并且在干预前后未量化异位。本研究不允许检查潜在的混杂因素，例如先前发生的 VT 风暴、合并症和发病机制。

Neuraxial modulation has the potential to reduce ventricular arrhythmias in patients with SHD. This form of treatment may be of value to control malignant ventricular arrhythmias when other treatment modalities have failed. Both TEA and LCSD may act as a bridge to definitive therapy such as catheter ablation, cardiac transplantation, or cardiac surgery. Larger prospective, randomized studies are needed to further define the clinical role of this therapeutic strategy. Prospective studies to evaluate sympathetic modulation in SHD are under way (http://www.clinicaltrials.gov/ct2/show/NCT01013714).
轴神经调节有可能减少 SHD 患者的室性心律失常。当其他治疗方式失败时，这种治疗形式可能有助于控制恶性室性心律失常。 TEA 和 LCSD 都可以充当导管消融、心脏移植或心脏手术等确定性治疗的桥梁。需要更大规模的前瞻性随机研究来进一步确定这种治疗策略的临床作用。评估 SHD 交感神经调节的前瞻性研究正在进行中 (http://www.clinicaltrials.gov/ct2/show/NCT01013714)。