反覆刺激迷走神經對心跳的影響

The Effects of Repeatedly Stimulating Vagus Nerve on Heart Rate

陳健治(Chien-Chih Chen,) ； 陳建良(Chieng-Liang Chen) ； 鄭秀貴(Shiow-Guey Jeng) ； 溫德生(Te-Sheng Wen)

《中華民國航空醫學暨科學期刊》 24卷2期 (2010/12) Pp. 83-90

https://doi.org/10.7011/JAMSRC.201012.0083

摘要

人體的安靜心跳率受到自律神經平衡性的影響，但在某些特殊的情形，如負G加速度和臉浸冷水可增進迷走神經的活性而導致心跳的減慢。如果以上述的方式反覆地刺激迷走神經，是否有加乘的作用？本研究共有28位男性大學生自願參加，採用驗浸4°C冷水（20秒）的方式刺激迷走神經，共三次（間隔15分鐘），以氧脈計記錄即時的心跳率（HR），以生物信號偵測計記錄刺激後15分鐘的心跳變異率（HRV），並分析分別代表迷走神經和交感神經活性的高頻率（HF）和低頻率（LF）電波的比率，遂發現每次臉浸冷水時，HR的降低甚快；HRV的分析顯示在45分鐘內HF逐漸增加，LF和HF／LF逐漸減少；而且第一次臉浸冷水後心跳率的降低程度與受試者的體能指數呈顯著的正相關。本研究的結果顯示以臉浸冷水的模式反覆地刺激迷走神經，已呈現若干程度的加乘作用，故推測刺激愈頻，其效果可能愈顯著。

關鍵字

迷走神經 ； 臉浸冷水 ； 心跳變異率 ； 負G加速度

並列摘要

Introduction: The resting heart rate (HR) is the result of sympathovagal balance. It was reported that sinus bradycardia could be induced by negative acceleration (-Gz) and facial immersion in cold water. The underlying mechanism is stimulating the efferent vagus nerve distributing on sino-atrial node. The goal of this study is to investigate if there is an additive effect when the vagus nerve is repeatedly stimulated. Methods: Thirty healthy male undergraduates volunteered to participate as subjects and their physical fitness were evaluated by step test previously. Cold water immersion (4°C, for 20 seconds) was conducted 3 times separated by 15 minutes. The beat-to-beat HR was monitored by an oximeter for recording the lowest HR during water immersion. The IS-minute heart rate variability (HRV) was also captured using a miniature physiological signal recorder after water immersion. The low-frequency (LF) and high-frequency (HF) powers were then analyzed. Results: The result showed that HR decreased very fast on each cold shock and reached the minimum within 13.5 seconds on average. Repeatedly stimulating vagus nerve gradually increased its activity which even surpassed that of sympathetic nerve after the last water immersion. Besides, the decreasing rate of HR at the moment of first water immersion correlates with the physical efficiency index of subjects. Conclusion: The finding of this study indicates the potential risk of frequently stimulation on vagus nerve during aerial combat maneuver.

並列關鍵字

vagus nerve ； water immersion ； heart rate variability ； negative acceleration