Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA. ; Department of Internal Medicine, Chonbuk National University School of Medicine, Jeonju, Korea.
Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA.
Korean Circ J. 2015 Mar;45(2):149-57. doi: 10.4070/kcj.2015.45.2.149. Epub 2015 Mar 24.
Recent studies showed that, in addition to parasympathetic nerves, cervical vagal nerves contained significant sympathetic nerves. We hypothesized that cervical vagal nerve stimulation (VNS) may capture the sympathetic nerves within the vagal nerve and activate the stellate ganglion.
We recorded left stellate ganglion nerve activity (SGNA), left thoracic vagal nerve activity (VNA), and subcutaneous electrocardiogram in seven dogs during left cervical VNS with 30 seconds on-time and 30 seconds off time. We then compared the SGNA between VNS on and off times.
Cervical VNS at moderate (0.75 mA) output induced large SGNA, elevated heart rate (HR), and reduced HR variability, suggesting sympathetic activation. Further increase of the VNS output to >1.5 mA increased SGNA but did not significantly increase the HR, suggesting simultaneous sympathetic and parasympathetic activation. The differences of integrated SGNA and integrated VNA between VNS on and off times (ΔSGNA) increased progressively from 5.2 mV-s {95% confidence interval (CI): 1.25-9.06, p=0.018, n=7} at 1.0 mA to 13.7 mV-s (CI: 5.97-21.43, p=0.005, n=7) at 1.5 mA. The difference in HR (ΔHR, bpm) between on and off times was 5.8 bpm (CI: 0.28-11.29, p=0.042, n=7) at 1.0 mA and 5.3 bpm (CI 1.92 to 12.61, p=0.122, n=7) at 1.5 mA.
Intermittent cervical VNS may selectively capture the sympathetic components of the vagal nerve and excite the stellate ganglion at moderate output. Increasing the output may result in simultaneously sympathetic and parasympathetic capture.
最近的研究表明，除了副交感神经，颈部迷走神经还包含显著的交感神经。我们假设颈部迷走神经刺激（VNS）可能会捕获迷走神经内的交感神经，并激活星状神经节。
我们在 7 只狗中记录了左侧星状神经节神经活动（SGNA）、左侧胸迷走神经活动（VNA）和皮下心电图，在左侧颈部 VNS 时设置 30 秒 ON 时间和 30 秒 OFF 时间。然后，我们比较了 VNS ON 和 OFF 时间的 SGNA。
中等强度（0.75 mA）输出的颈部 VNS 诱导出较大的 SGNA、心率升高（HR）和 HR 变异性降低，提示交感神经激活。进一步增加 VNS 输出至>1.5 mA 会增加 SGNA，但不会显著增加 HR，提示同时激活了交感神经和副交感神经。VNS ON 和 OFF 时间之间的整合 SGNA 和整合 VNA 差异（ΔSGNA）从 1.0 mA 时的 5.2 mV-s（95%置信区间[CI]：1.25-9.06，p=0.018，n=7）逐渐增加到 1.5 mA 时的 13.7 mV-s（CI：5.97-21.43，p=0.005，n=7）。ON 和 OFF 时间之间的 HR 差异（ΔHR，bpm）在 1.0 mA 时为 5.8 bpm（CI：0.28-11.29，p=0.042，n=7），在 1.5 mA 时为 5.3 bpm（CI：1.92 至 12.61，p=0.122，n=7）。
间歇性颈部 VNS 可能会选择性地捕获迷走神经的交感成分，并在中等输出时兴奋星状神经节。增加输出可能会导致同时捕获交感神经和副交感神经。
