By enhancing vagal activity, auricle transcutaneous electric nerve stimulation (TENS) is developed as a non-invasive therapy for heart failure. Nevertheless, though shoulder TENS used for treating adhesive capsulitis could affect vagal tone, its potential impact on heart functions remains unclear. In this study, electrocardiogram (ECG) and heart rate (HR) of subjects in response to sham, right-sided, or left-sided shoulder TENS (TENS-S, TENS-R, and TENS-L, respectively; 5 min) were recorded and analyzed. During the stimulation period, TENS-R constantly and TENS-L transiently decreased the HR of subjects; both TENS-R and TENS-L increased powers of the low- and high-frequency spectra. While TENS-R exhibiting no effect, TENS-L increased the ratio of low/high-frequency power spectrum indicating TENS-R decreased the HR through potentiating cardiac vagal tone. Collectively, these results suggest TENS could be an early and non-invasive therapy for heart failure patients before considering implant devices or devices are not feasible; moreover, therapists/physicians need to carefully monitor the potential adverse events during treatment for patient safety.

Trial registration: The study protocol was registered in ClinicalTrials.gov (NCT03982472; 11/06/2019).

通过增强迷走神经活动，耳廓经皮神经电刺激 (TENS) 被开发为心力衰竭的非侵入性疗法。然而，尽管用于治疗肩周炎的肩部 TENS 会影响迷走神经张力，但其对心脏功能的潜在影响仍不清楚。在本研究中，受试者对假手术、右侧肩部或左侧肩部 TENS（分别为 TENS-S、TENS-R 和 TENS-L；5 分钟）的反应的心电图 (ECG) 和心率 (HR)被记录和分析。在刺激期间，TENS-R持续和TENS-L短暂降低受试者的HR；TENS-R 和 TENS-L 都增加了低频和高频频谱的功率。虽然 TENS-R 没有效果，TENS-L 增加了低频/高频功率谱的比率，表明 TENS-R 通过增强心脏迷走神经张力降低了 HR。总的来说，这些结果表明，在考虑植入设备或设备不可行之前，TENS 可能是心力衰竭患者的早期非侵入性治疗；此外，治疗师/医师需要仔细监测治疗期间的潜在不良事件，以确保患者安全。

试验注册：研究方案已在 ClinicalTrials.gov 注册（NCT03982472；11/06/2019）。