Staley Rachel, Garcia Ronald G, Stowell Jessica, Sclocco Roberta, Fisher Harrison, Napadow Vitaly, Goldstein Jill M, Barbieri Riccardo
Annu Int Conf IEEE Eng Med Biol Soc. 2020 Jul;2020:2581-2584. doi: 10.1109/EMBC44109.2020.9175768.
The objective of this study was to determine potential effects of Respiratory-gated Auricular Vagal Afferent Nerve Stimulation (RAVANS) on cardiac autonomic activity in hypertensive patients.20 hypertensive subjects (57.3±6.2 years; 11 females, 9 males) were randomized to receive either active RAVANS at 25 Hz or sham stimulation for 5 consecutive days and were assessed 5 and 10 days later. Continuous electrocardiogram, pulse rate, and blood pressure signals were collected during 10-minute baseline, 30-minute stimulation, and 10-minute recovery periods for each session. LabChart was used to acquire and process heart rate variability and blood pressure indices. Percent changes of mean values during the recovery period were calculated comparing the final stimulation session and follow-up sessions to the first stimulation session. General linear models were applied to assess the effects of RAVANS on the variables evaluated, considering baseline values and sex as covariates in the models.We found that RAVANS increased high frequency (HF-HRV) power during recovery of the final stimulation session and both follow-up sessions in comparison to sham. RAVANS also lowered heart rate and increased average RR and root mean square of successive RR interval differences (RMSSD) during recovery on the final day of stimulation. No significant effects on blood pressure values were observed during these periods.These results suggest that RAVANS effectively stimulates cardiovagal activity in hypertension, with effects lasting up to 10 days. Future research incorporating larger sample sizes is needed to replicate the effects of RAVANS.Clinical Relevance- This research has implications for potential therapeutic effects of respiratory-gated tVNS on cardiovagal modulation in hypertensive patients.
本研究的目的是确定呼吸门控耳迷走神经刺激（RAVANS）对高血压患者心脏自主神经活动的潜在影响。20名高血压受试者（57.3±6.2岁；11名女性，9名男性）被随机分为两组，一组连续5天接受25Hz的主动RAVANS刺激，另一组接受假刺激，分别在5天和10天后进行评估。在每次测试的10分钟基线期、30分钟刺激期和10分钟恢复期收集连续心电图、脉搏率和血压信号。使用LabChart获取和处理心率变异性和血压指标。通过比较最后一次刺激期和随访期与第一次刺激期，计算恢复期平均值的百分比变化。应用一般线性模型评估RAVANS对所评估变量的影响，在模型中将基线值和性别作为协变量。我们发现，与假刺激相比，RAVANS在最后一次刺激期及两个随访期的恢复期均增加了高频（HF-HRV）功率。在刺激最后一天的恢复期，RAVANS还降低了心率，增加了平均RR间期和连续RR间期差值的均方根（RMSSD）。在此期间未观察到对血压值有显著影响。这些结果表明，RAVANS能有效刺激高血压患者的心脏迷走神经活动，其作用可持续长达10天。未来需要纳入更大样本量的研究来重复RAVANS的效果。临床意义——本研究对呼吸门控经皮迷走神经刺激（tVNS）对高血压患者心脏迷走神经调制的潜在治疗作用具有启示意义。
