Background

Type 3 long QT syndrome (LQT3) is caused by pathogenic, gain-of-function variants in SCN5A leading to a prolonged action potential, ventricular ectopy, and torsades de pointes. Treatment options include pharmacotherapy, cardiac denervation, and/or device therapy. Rarely, patients with malignant LQT3 require cardiac transplantation.

Objective

The purpose of this study was to evaluate the role of chronic continuous intravenous (IV) lidocaine as a therapeutic option for select patients with LQT3 refractory to standard therapy.

Methods

We performed a retrospective review of patients evaluated and treated at Mayo Clinic and identified 4 of 161 patients with LQT3 (2.5%) who were refractory to standard therapies and therefore treated with IV lidocaine.

Results

There were 4 patients (2 female [50%]). The median age at first IV lidocaine infusion was 2 months (interquartile range 1.5–4.8 months), and the median cumulative duration on IV lidocaine was 11.5 months (interquartile range 8.7–17.8 months). The main indication for IV lidocaine in all patients was persistent ventricular arrhythmias. Before IV lidocaine, all patients received an implantable cardioverter-defibrillator, and while on intermittent IV lidocaine, all patients underwent bilateral cardiac sympathetic denervation. Additionally, 2 (50%) patients had cardiac ablation for premature ventricular complexes. In all patients, lidocaine infusion resulted in a significant reduction of LQT3-triggered cardiac events. The main side effects of IV lidocaine observed were dizziness (n = 2, 50%) and seizures (n = 2, 50%). During follow-up, 3 of 4 (75%) patients underwent orthotopic cardiac transplantation. The remaining patient continues to receive IV lidocaine bolus for rescue as needed.

Conclusion

For patients with LQT3 who are refractory to standard treatment, chronic IV lidocaine infusion can be used as a potential “bridge to transplant.”

中文翻译：

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慢性持续静脉利多卡因在恶性 3 型长 QT 综合征患者临床管理中的作用

背景

3 型长 QT 综合征 (LQT3) 是由SCN5A的致病性功能获得性变异引起的，导致动作电位延长、心室异位和尖端扭转型室性心动过速。治疗选择包括药物疗法、心脏去神经支配和/或器械疗法。很少有恶性 LQT3 患者需要心脏移植。

客观的

本研究的目的是评估慢性持续静脉注射 (IV) 利多卡因作为标准治疗难治的 LQT3 患者的治疗选择的作用。

方法

我们对在 Mayo Clinic 评估和治疗的患者进行了回顾性审查，确定了 161 名 LQT3 患者中的 4 名（2.5%），这些患者对标准疗法无效，因此接受了 IV 利多卡因治疗。

结果

有 4 名患者（2 名女性 [50%]）。首次 IV 利多卡因输注的中位年龄为 2 个月（四分位距 1.5-4.8 个月），IV 利多卡因的中位累积持续时间为 11.5 个月（四分位距 8.7-17.8 个月）。所有患者静脉注射利多卡因的主要适应症是持续性室性心律失常。在静脉注射利多卡因之前，所有患者都接受了植入式心脏复律除颤器，而在间歇性静脉注射利多卡因时，所有患者都接受了双侧心脏交感神经去神经支配。此外，2 名 (50%) 患者对室性早搏进行了心脏消融术。在所有患者中，利多卡因输注导致 LQT3 触发的心脏事件显着减少。观察到的 IV 利多卡因的主要副作用是头晕 (n = 2, 50%) 和癫痫发作 (n = 2, 50%)。随访期间，4 名患者中有 3 名 (75%) 接受了原位心脏移植。其余患者继续接受静脉注射利多卡因以根据需要进行抢救。

结论

对于标准治疗无效的 LQT3 患者，长期静脉输注利多卡因可作为潜在的“移植桥梁”。