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Objective To explore the effects of particulate matters less than 2.5 μm in aerodynamic diameter (PM2.5) on heart repolarization/depolarization and heart rate variability (HRV). Methods We conducted a panel study for elderly subjects with heart disease in Beijing from 2007 to 2008. PM2.5 was measured at a fixed station for 20 h continuously each day while electrocardiogram (ECG) indexes of 42 subjects were also recorded repeatedly. Meteorological data was obtained from the China Meteorological Data Sharing Service System. A mixed linear regression model was used to estimate the associations between PM2.5 and the ECG indexes. The model was adjusted for age, body mass index, sex, day of the week and meteorology. Results Significant adverse effects of PM2.5 on ECG indexes reflecting HRV were observed statistically and the strongest effect of PM2.5 on HRV was on lag 1 day in our study. However, there were no associations between PM2.5 and ECG indexes reflecting heart repolarization/depolarization. Additionally, the effects of PM2.5 on subjects with hypertension were larger than on the subjects without hypertension. Conclusion This study showed ambient PM2.5 could affect cardiac autonomic function of the elderly people with heart disease, and subjects with hypertension appeared to be more susceptive to the autonomic dysfunction induced by PM2.5.
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Objective: To analyze the heart rate variability in Chinese PLA navy global visiting task group. Methods:We analyzed the heart rate variability in Holter in 77 men and 4 women for 5-15 days before voyage, and 65-75 and 115-125 days after voyage, and 29 men and 3 women for 5-15 days after having finished voyage. Results:NN50 and VLF were lower in 77 men and 4 women for 65-75 days after voyage than that was 5-15 days before voyage (P<0.01). SDANN was lower in 77 men and 4 women for 115-125 days after voyage than that was 65-75 days after voyage (P<0.01). SDNN, SDANN, SDNN index, RMSSD, NN50, PNN50,Triangular index, VLF, HLF, VAI and VLI were lower in 77 men and 4 women for 65-75 days after voyage than that was 5-15 days before voyage (P<0.01).Conclusion: These findings suggest that voyage may reduce heart rate variability for a long time.
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健康人心率震荡的昼夜节律及其与心率变异性的相关性分析
心率震荡(heart rate turbulence,HRT)的病理生理机制至今仍未完全阐明,一些资料表明其与压力反射敏感性高度相关,且矣胄穆时湟煨?heart rate variability,HRV)之间也存在显著的相关关系.
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心率变异性和内皮素-1与急性冠脉综合征预后的相关性分析
大量的研究表明,心率变异性的分析能有效评价心脏植物神经功能状态,是判断多种心血管疾病预后的一个相对独立性较强、相关性较好的指标.
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温度对心率和心率变异的影响
心率变异(heart rate variability,HRV)是判断自主神经活动好的定量指标,有时域、频域和非线性等研究方法.频域方法适用于短时程记录,而时域法对分析长时程记录较为理想.HRV的发生基础是自主神经对心率的调节作用,反映了神经体液因素与窦房结相互作用的平衡关系.心率变异受诸多外周和中枢因素的影响,体温及环境温度的变化影响着心血管活动的调节,是HRV的重要起因.极低频(very low frequencies,VLF)功率受温度刺激(如低体温和体温调节活动)的调制,皮肤降温不会特异的影响此频带,表明功率谱中特别频带的改变依赖于体温调节激发模式,而不是体温调节本身.中枢神经系统的损伤可引起心脏自主神经的异常活动并降低HRV,低体温处理可以使HRV的降低更显著.因此研究体温及环境温度与HRV的关系具有非常重要的实用价值.
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原发性高血压患者夜间静息心率及心率变异性的特点
原发性高血压病的确切病因尚不明确,已有大量的研究证明,高血压病的发生发展与诸多因素的作用有关.交感神经活动的增强是高血压病发病机制中的重要环节[1],心率变异(HRV)能反映交感和迷走神经对心血管系统平衡的调节.
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老年冠心病患者腹腔镜胆囊切除术中CO2气腹对心率变异性的影响及星状神经节阻滞对气腹的干预作用
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影响心率变异因素的研究进展
临床医师和电生理学家早在1933年就注意到,健康人在静息状态下呈现R-R间期的周期性变化,这种变化主要受呼吸、体位、压力感受器和温度调节的影响,并证实是通过影响交感和迷走神经活动来改变R-R间期的周期性,正常人交感-迷走神经保持一定的紧张度,互相制约,互相影响达到动态平衡,使成年人心率保持在60~100bpm,任何兴奋交感神经,减低迷走神经张力,抑制迷走神经反射的因素,都可使R-R间期周期性变化减少,R-R间期的微小变化称心率变异(HRV)。HRV作为反映神经体液因素对心血管精细调节的敏感指标,在临床具有很好的应用价值,众多的研究表明,HRV能反映植物神经交感和迷走神经,特别是迷走神经对机体平衡的调节,也能反映在生理、病理状态下两者的不平衡以及在各种干预引起的交感、迷走神经张力,特别是迷走神经张力的变化,所以,任何影响心率的生理、病理因素和人为干预均可影响HRV。此外,不同的检测方法,检测仪器性能的不同,采用指标的不同等,都可影响结果,因此,严格检测条件,实现HRV检测的标准化,对临床正确应用HRV有重要意义。