Zhang Jun, Cao Qinqin, Li Rongrong, Hu Jingze, Dai Jiafei, Zhang Hao, Wang Huaiming, Yang Fang, Ye Ruidong, Liu Xinfeng, Xu Gelin
aDepartment of Neurology, Jinling Hospital, Medical School of Nanjing University, Nanjing, Jiangsu bDepartment of Neurology, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, Shandong cDepartment of Neurology, Jinling Hospital, Second Military Medical University, Nanjing, Jiangsu, China *Jun Zhang and Qinqin Cao contributed equally to the article.
J Hypertens. 2017 Aug;35(8):1676-1684. doi: 10.1097/HJH.0000000000001367.
Carotid baroreflex plays a crucial role in regulating arterial pressure. Based on this knowledge, electrical stimulation of carotid sinus was designed for treating resistant hypertension. However, the clinical implication of electrical stimulation of carotid sinus is largely restrained due to obvious invasiveness. This study aimed to evaluate the efficacy of magnetic stimulation of carotid sinus (MSCS), a noninvasive strategy, for lowering blood pressure in rabbits.
MSCS with graded intensities and frequencies were systematically attempted in normotensive rabbits. Blood pressure was recorded dynamically. Sinoaortic denervation and plasma hormone level analyses were performed.
When the right carotid sinus was stimulated at 1 Hz frequency, a dose-effect relationship was observed between stimulation intensity (100-250% motor threshold) and mean arterial pressure (MAP) decrement (3.6 ± 1.0 to 10.4 ± 2.3 mmHg). When stimulation intensity was fixed at 200% motor threshold, the median reduction of MAP in 1-Hz group [10.8 (8.6-14.9) mmHg] was significantly higher than that in other frequency groups (all P < 0.05). Heart rates declined transiently after the initiation of MSCS. Compared with baseline (33.9 ± 5.5 pg/ml), plasma epinephrine level increased during MSCS (88.1 ± 9.6, P = 0.002). After ipsilateral sinoaortic denervation, MAP decrement (7.0 ± 0.8 mmHg) was remarkably blunted compared with that in sham animals (13.0 ± 1.1 mmHg, P = 0.001).
The current study demonstrated that MSCS treatment can lower the arterial pressure in normotensive rabbits. This preliminarily result warrants further studies to establish the efficacy of MSCS in treating refractory hypertension.
颈动脉压力反射在调节动脉血压中起关键作用。基于这一认识，设计了颈动脉窦电刺激来治疗顽固性高血压。然而，由于明显的侵入性，颈动脉窦电刺激的临床应用受到很大限制。本研究旨在评估一种非侵入性策略——颈动脉窦磁刺激（MSCS）降低兔血压的效果。
对正常血压的兔系统性地尝试不同强度和频率的MSCS。动态记录血压。进行去窦神经支配和血浆激素水平分析。
当以1Hz频率刺激右侧颈动脉窦时，观察到刺激强度（100 - 250%运动阈值）与平均动脉压（MAP）下降（3.6±1.0至10.4±2.3mmHg）之间存在剂量 - 效应关系。当刺激强度固定在200%运动阈值时，1Hz组MAP的中位数下降[10.8（8.6 - 14.9）mmHg]显著高于其他频率组（均P<0.05）。MSCS开始后心率短暂下降。与基线（33.9±5.5pg/ml）相比，MSCS期间血浆肾上腺素水平升高（88.1±9.6，P = 0.002）。同侧去窦神经支配后，MAP下降（7.0±0.8mmHg）与假手术动物（13.0±1.1mmHg，P = 0.001）相比明显减弱。
当前研究表明MSCS治疗可降低正常血压兔的动脉压。这一初步结果值得进一步研究以确定MSCS治疗难治性高血压的疗效。
