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长期接触噪声可以导致心律失常、心肌缺血性改变和冠心病.但在多次研究中发现存在不同的结果.这可能是多种社会环境因素的干扰所造成的,而动物实验可以控制和避免这些干扰.本研究采用一种新的检测清醒、自由活动大鼠心电图的方法,观察了100 dB(A)噪声短期暴露(1h)过程中雄性大鼠心率和心电ST段的变化.实验发现,噪声暴露前大鼠的心率和心电ST段平稳,噪声暴露0～4 min时,心率下降至最低点(下降约60 beats/min),然后逐渐回升.心电ST段在噪声暴露开始后逐渐升高,到15～29 min时,心电ST段升高达最大值(约升高30μV,然后逐渐下降.噪声停止后,心率和心电ST段迅速恢复至噪声暴露前水平.上述心率和心电ST段的变化具有以下特点:1.具有稳定性和可重复性,在连续3 d实验中心率和心电ST段出现相同的变化;2.存在个体差异,根据心率和心电ST段对噪声反应的特征,可将大鼠分为两种反应类型:A类反应噪声暴露期间心率下降、心电ST段升高;B类反应心率和心电ST段基本不变.还发现心电ST段基础值A类反应大鼠高于B类反应大鼠约45％;3.心率和心电ST段的变化存在着平行关系,即心率下降的大鼠心电ST段升高(A类反应)、心率不变的大鼠心电ST段也多不变(B类反应).
Long-term exposure to noise can lead to arrhythmia, myocardial ischemia, and coronary heart disease, but different results have been found in multiple studies, which may be caused by disturbances of various social environmental factors that can be controlled and avoided by animal experiments In this study, we used a new method to detect awake and free-moving ECG in rats and observed the changes of heart rate and ST segment in male rats during short-term exposure (1h) of 100 dB (A) noise. , The heart rate and electrocardiogram of ST segment in rats before noise exposure were stable, the heart rate dropped to the lowest point (about 60 beats / min) at 0-4 min after noise exposure, and then gradually recovered.The electrocardiogram ST segment was at the beginning of noise exposure Gradually increased, ST-segment elevation reached the maximum (about 30μV, then decreased gradually after 15 to 29 min.) After the noise stopped, the ST segment of heart rate and ECG quickly recovered to the level before noise exposure. ST segment changes in ECG has the following characteristics: 1. With stability and repeatability, in the continuous 3 d experimental heart rate and ECG ST segment the same changes; 2. There are individual differences, according to the heart rate and ECG ST segment The characteristics of the response to noise can be rat For the two types of reaction: heart rate decreased during Class A reaction noise exposure, ECG ST segment elevation; type B reaction heart rate and ECG ST segment basically unchanged.It was found that ST-segment ECG value of type A response in rats was higher than B type rats were about 45%; 3. There was a parallel relationship between heart rate and ST segment changes in heart rate, namely, the ST segment elevation (A type reaction) in rat with decreased heart rate, heart electrocardiogram ST segment is also constant (B type reaction).