Objective To investigate the effect of occupational noise on heart rate turbulence (HRT) in workers.Methods A total of 96 workers occupationally exposed to noise enrolled as exposed group and 95 workers without noise exposure enrolled as control group were chosen for examination of 24 h dynamic electrocardiograph (Holter).A total of 51 workers of exposed group showed ventricular premature complexes,while in workers of control group,49 workers showed ventricular premature complexes in records of Holter.According to two basic indices:turbulence onset(TO)and turbulence slope(TS) were obtained,the cut-off values for positive results in TO and TS were≥0 and ≤2.5 ms/RRI.Thereby,HRT might be classified into three categories:HRT 0 (TO＜0 and TS＞2.5 ms/RRI),HRT 1 (TO≥0 or TS≤2.5 ms/RRI) and HRT 2 (TO≥0 and TS≤2.5 ms/RRI).Results The results showed that compared with the control group,the levels of TO in exposed group were significantly higher [(-0.01±3.18)％ VS (-1.72±2.09)％],while the level of TS was significantly lower than that in control group [(7.23± 4.33) ms/RRI vs (9.72±5.03) ms/RRI,P＜0.05)];additionally,the proportion of HRT 0 in exposed group was significantly lower than that in control group (41.2％ vs 79.6％,P＜0.05),the proportions of HRT 1 and HRT 2 in exposed group were significantly higher than that in control group (39.2％ vs 16.3％ and 19.6％ vs 4.1％,P＜0.05).Conclusion The results indicated that HRT in noise exposed workers was significantly attenuated,which suggested that occupational noise exposure may result in impairment of cardiac autonomic nerve's activity.

[目的]研究噪声对作业工人心率变异性(heart rate variability,HRV)的影响.[方法]选取某公司动力车间单纯接触噪声的作业人员96人为噪声接触组,同时选取同一单位不接触噪声的工作人员95人为对照组,两组均进行24 h动态心电图检查,测量或计算24 h平均心率(HR)和HRV时域指标24 h全部窦性RR间期的标准差(SDNN)、24 h内全部窦性RR间期差值的均方根(RMSSD)、24 h内相邻两个正常窦性RR间期差值大于50 ms的个数所占的百分数(PNN50),及频谱指标高频功率(HF)、低频功率(LF)、极低频功率(VLF),比较接触组与对照组各指标的差异,并分析接触组HRV各指标与工龄、年龄、性别、HR的相关性.[结果]接触组SDNN、PNN50、LF、VLF低于对照组,HR高于对照组(P<0.05);接触组中SDNN、PNN50、LF、VLF与工龄及HR呈负相关(r=-0.582~-0.283,P<0.05),与性别无相关性(P>0.05),SDNN、PNN50、LF与年龄呈负相关(r=-0.233~-0.211,P<0.05).[结论]噪声作业工人心率变异性降低,提示长期的噪声接触可引起作业工人自主神经功能紊乱.

Objective:To investigate the change of heart rate turbulence(HRT)including turbulence timing(TT),turbulence onset(TO) and turbulence slope(TS) and its correlation with age,heart rate(HR) before ventricular premature complexes(VPCs),coupling interval,compensatory pause,left atrial dimension(LAD),left ventricular end-diastolic dimension(LVEDD) and left ventricular ejection fraction(LVEF) in patients with chronic heart failure(CHF).Methods:A total of 79 patients with chronic heart failure(CHF group) and 51 patients without organic heart disease(control group) were assigned.TO,TS,TT,HR before VPCs,coupling interval,compensatory pause,LAD,LVEDD and LVEF were determined by 24h ambulatory electrocardiograph(Holter) and ultrasonic cardiogram(UCG).The value of above indexes was compared between two groups.The correlation of HRT with other indexes was analyzed.Results:The levels of TT,TO,LAD,LVEDD in CHF group were significantly higher than those in control group,and TS,LVEF were lower in control group(P0.05).In CHF group,TO was negatively correlated with TS(P=0.028) and LVEF(P=0.023),TS was negatively correlated with HR before VPCs(P=0.002),and was positively correlated with coupling interval(P=0.008) and compensatory pause(P=0.024).In control group,TO was positively correlated with age(P=0.009) and coupling interval(P=0.049).TS was negatively correlated with HR before VPCs(P=0.006)and was positively correlated with compensatory pause(P=0.014).In both two groups.TT was not correlated with all the other indexes(P0.05).Conclusions:HRT appeares significantly blunted in patients with CHF,TT increasing indicates that the deceleration of HR after VPCs delays.TT may be a more objective index for predicting for high-risk patients.

Objective The health conditions of workers with long-term occupational exposure to low-level acrylonitrile were compared with those of non-exposed workers to observe the adverse health effect of acrylonitrile.Methods The medical examination data of 733 acrylonitrile-exposed workers and 610 health workers were collected and compared.Results There was no difference of gender ratio,age,drinking history and the body mass index between these two groups.The blood lipid and sugar level,the incidence of fatty liver and ALT abnormality of exposed group were similar to those of the reference workers.However,the incidence of hepatic cyst,liver echo enhancement and elevated AKP in acrylonitrile-exposed group were significantly higher than in the controls.Conclusion The possible liver damage induced by acrylonitrile should be investigated among workers with long-term exposure to low-level acrylonitrile.