立位耐力不良飞行员的血液动力学指标与心率变异性的改变

Changes of heart rate variability and hemodynamics in pilots with low orthostatic tolerance.

目的探讨易发血管神经性晕厥飞行员的评价方法。方法对３０例有晕厥史的立位耐力不良飞行员（阳性组）、２０例有晕厥史的立位耐力正常飞行员（阴性组）和１５例健康飞行员（对照组），通过立位耐力试验结合心率变异性（ＨＲＶ）分析进行血压、心率与时域、频域指标的比较，按照国际常用标准进行判断分析。结果阳性组立位耐力试验前平均心率（ＨＲ）、收缩压（ＳＢＰ）、舒张压（ＤＢＰ）与阴性组、对照组比较，无显著性差异（Ｐ＞０．０５）。试验后，阳性组平均心率明显高于阴性组和对照组，ＳＢＰ、ＤＢＰ则明显低于阴性组，三组之间有显著性差异（Ｐ＜０．０１）。ＨＲＶ各项指标中阳性组２４ｈ的连续Ｒ－Ｒ间期标准差（ＳＤＮＮ）、ＨＲＶ三角指数（ＨＲＶＩ）、Ｒ－Ｒ间期平均值（Ｒ－Ｒ）明显小于阴性组和对照组；平均１ｈ功率频谱分析表明，低频成分（ＬＦ）与高频成分（ＨＦ）比值在三组间有显著性差异，即阳性组ＬＦ／ＨＦ比值明显高于阴性组和对照组。通过直线相关分析发现，阳性组试验后ＨＲ与连续Ｒ－Ｒ间期的标准差（ＳＤＮＮ）呈明显的负相关（ｒ＝－０．７７９，Ｐ＜０．０１）；ＤＢＰ与ＨＲＶＩ呈明显的正相关（ｒ＝０．８１０，Ｐ＜０．０１）。结论飞行员立位耐力不良者有明显的心?

Objective To explore the method for detecting the pilots susceptible to vasoneural syncope in pilots. Methods Thirty pilots with low orthostatic tolerance served as subjects (positive group, PG), 20 pilots with normal orthostatic tolerance as negative controls (negative group, NG) and 15 healthy pilots as healthy controls (control group,CG). Orthostatic tolerance test(OTT) combined with heart rate variability (HRV), blood pressure, heart rate, time and frequency domain were compared and analysized among three groups according to common international standard. Results HR, SBP, DBP were not significantly different ( P >0.05) between three groups before OTT, while after test HR in PG was higher than those in NG and CG, SBP and DBP in PG were lower than those in NG, and significantly different ( P <0.01) between three groups. Twenty four hours continuous R R interval standard difference (SDNN), HRV triangle index(HRVI), and R R interval average value in PG were significantly lower than those in NG and CG; power spectrum analysis of mean 1 hour for low frequency part (LF) and high frequency part (HF) were significantly different between three groups, that was LF/HF ratio in PG was higher than that in NG ad CG. HR and SDNN was negatively correlated ( r =-0.779, P <0.01) in PG after test, while DBP and HRVI was positively correlated ( r =0.810, P <0.01). Conclusion There is dysfuction of cardiovascular autonomic nervous regulation in pilots with low orthostatic tolerance. OTT combined with HRV analy sis can distinguish objectively the pilots susceptible to vascular nervous syncope