有空中晕厥史飞行员微循环的特征及其可能的影响

目的 探讨微循环与空中晕厥发生的关系。方法试验对象为39名有空中晕厥文的飞行员并设对照健康组飞行员46人。两组飞行员均作常规主动立位耐力试验，试验前后测量血压、心率和微循环各项指标。结果 两组立位耐力试验后，晕厥组多项指标与对照组差异明显，特别是管拌数目、心率、收缩压、血管长度、拌顶宽度、输入枝、输出枝直径等(P＜0．05)。而多数变化从立位即刻开始至立位后20min持续加深而血压进一步下降。结论 微循环的变化与易发空中晕厥有关系，改善微循环对预防和矫治空中晕厥可能有意义。     

立位耐力试验对血管迷走性晕厥和加速度意识丧失的诊断价值

晕厥是指意识与体态张力的突然、短暂丧失。血管迷走性晕厥(vasovagal syncope,VVS)是神经介导性晕厥和神经介导性晕厥综合征的一种特殊形式,也是最常见的。加速度所致的意识丧失(Ginduced loss of consciousness,G-LOC)是军事航空医     

飞行员Coriolis加速度刺激下血浆激素水平的变化

为探讨Ｃｏｒｉｏｌｉｓ加速度刺激下，健康飞行员与有晕厥史飞行员（立位耐力阳性者）某些内分泌激素的区别，选健康飞行员与有晕厥史的飞行员各１２名，分别间隔３～４ｍｉｎ间断累加地给与３．７５π＾２ｃｍ／ｓ＾２，５．００π＾２ｃｍ／ｓ＾２，６．２５π＾２ｃｍ／ｓ＾２的Ｃｏｒｉｏｌｉｓ加速度刺激，用放射免疫法测定血管紧张素－Ⅱ，醛固酮，皮质醇，胰岛素，胃泌素，结果显示：两组飞行员在Ｃｏｒｉｏｌｉｓ加速度刺激     

中国歼击机飞行员立位耐力试验正常参考值

目的为了评价中国歼击机飞行员立位耐力水平及建立中国歼击机飞行员立位耐力试验正常值.方法应用自行研制的立位耐力监测系统,对177例中国歼击机飞行员进行立位耐力试验(OTT).该系统是由计算机控制倾斜床和自动记录多项生理指标系统组成.结果从立位即刻到持续20min,受试者最高心率平均为(84.8±11.9)次/min,最低平均收缩压(SP)、舒张压(DP)和平均动脉压(MAP)分别是(119.0±11.3)mmHg、(74.4±10.3)mmHg和(89.7±10.1)mmHg.结论按95%可信度,建议中国歼击机飞行员立位耐力试验正常参考值可以用104次/min作为OTT心率上限,而100mmHg、57mmHg和73mmHg分别为SP、DP和MAP的下限,越限者应视为OTT阳性.     

飞行人员立位耐力不良与小心脏的研究

按照X线片心胸比小于0.40;心脏阴影横径小于12cm;超声心动图左室舒张末内径小于4.2cm;γ-核素心排血指数小于3.0mm/cm,被诊断为小心脏之飞行员10例(丙组),与心脏正常而立位耐力不正常之飞行员(乙组)和心脏正常,立位耐力也正常之飞行员(甲组)比较,在立位耐力试验中从站立即刻起,丙组心率     

飞行员空中晕厥1例

1 临床资料 歼教-5飞行员,34岁,飞行时间1900h。在间断飞行一个月后恢复特技飞行,适逢转场后第一个飞行日,第一架次。飞行前准备充分,无任何不适,此前几天身体良好,饮食睡眠正常。担任双机编队复杂特技僚机,在前舱。进入空域后由后舱飞行员做特技。在退出半滚倒转时,加速度值为4～5G之间,突感眼前     

加速度晕厥飞行人员立位耐力试验的医学鉴定及护理作用

对67例加速度晕厥飞行人员进行常规立位耐力试验,说明该试验可以客观地评价飞行人员在低G值下的耐力情况,同时阐明了进行该试验的护理作用,提出在进行该试验时对护士的几点要求。     

飞行员空中晕厥1例原因分析

飞行人员空中晕厥的发生,难以预料,对飞行安全危害大。我部发生的1例险些酿成严重事故,报道如下: 1 晕厥过程 歼-6飞行员李某,飞行总时间730h。在一次昼间气象飞行日,先飞了两次航行攻截击综合练习,身体感觉不适,第3次由大队长带飞综合特技。飞机升至10000m后,由大队长示范第1套动作,顺序是:半滚     

直立倾斜试验与晕厥评价

晕厥是一种突发性，短暂性，一过性的意识丧生，由于一时性，广泛性脑缺血，缺氧引起，并在短时间内自然恢复。60％－70％的晕厥患者找不到明确原因，为不明原因晕厥，近年来开展的直立倾斜试验及异丙基肾上腺素激发的倾斜试验对诊断原因不明晕厥是一种有价值的方法。本文总结了倾斜试验诊断不明原因晕厥的价值，试验方法，临床应用情况，注意事项及研究进展。     

21d头低位卧床期间第一周和最后一周下体负压锻炼对立位耐力和心功能的影响

目的观察在 2 1d头低位卧床的第一周和最后一周进行下体负压锻炼对立位耐力和心功能的影响。方法 1 2名健康男性志愿者 ,随机分为对照组和LBNP组 ,每组 6人 ,均参加 - 6°头低位倾斜卧床实验。对照组在卧床期间不做任何处理 ,LBNP组在卧床第一周和最后一周 ,每天进行 1h、- 30mmHg的下体负压锻炼。卧床前和卧床第 1 0、2 1天在倾斜床上进行 3次立位耐力检查 ,卧床期间测量心脏泵血和收缩功能等指标。结果卧床前两组 1 2名被试者均顺利通过立位耐力检查。卧床第 1 0和 2 1天 ,对照组所有被试者均不能通过立位耐力检查 ,而下体负压组仅有 1人未通过 ,卧床第 2 1天下体负压组( 1 9.7± 0 .9min)平均耐受时间较对照组 ( 1 5 .0± 3.2min)显著延长 (P <0 .0 5 )。对照组每搏输出量(SV)及心输出量 (CO)在卧床第 3、1 0天较卧床前显著降低 (P <0 .0 5 ) ,而LBNP组SV及CO在卧床期间均无显著性变化 ;两组的射血前期 (PEP) /左室射血时间 (LVET)在卧床第 3、1 4天均显著升高 (P <0 .0 5 )。两组间比较 ,LBNP组PEP/LVET在卧床第 3天较对照组显著降低 (P <0 .0 5 ) ,LVET在卧床第 3、7和 1 4天较对照组显著升高 (P <0 .0 5 )。结论 2 1d头低位卧床可引起立位耐力、心脏泵血和收缩功能显著降低 ;在 2 1d头低位卧床的     

Autonomic testing for prediction of competition performance in Paralympic athletes

While we now appreciate that autonomic dysfunction can impact wheelchair rugby performance, this is currently not being assessed during classification, largely due to lack of a standardized and evidence‐based strategy to assess autonomic function. Our aim, therefore, was to establish the optimal autonomic testing protocol that best predicts cardiovascular capacity during competition by comprehensively examining autonomic function in elite wheelchair rugby athletes with cervical SCI and thereby enhance the standardized classification. Twenty‐six individuals with cervical SCI (C4‐C8; AIS A, B, C) participated in this study during the 2015 Parapan American Games in Toronto, Canada. Clinic autonomic testing included: sympathetic skin responses, baseline hemodynamics, orthostatic challenge test, and cold‐pressor tests. Further, we completed standard motor/sensory assessments and obtained each participants’ International Wheelchair Rugby Federation classification. These clinic metrics were correlated to in‐competition heart rate monitoring obtained during competition. The current study provides novel evidence that the change in systolic blood pressure during an orthostatic challenge test predicts approximately 50% of the in‐competition peak heart rate (P <.001). Conversely, International Wheelchair Rugby Federation classification was poorly associated with in‐competition peak heart rate (R ²=.204; P <.05). Autonomic testing provides deep insight regarding preserved autonomic control after SCI that is associated with performance in elite wheelchair rugby athletes. As such, incorporating assessments of cardiovascular capacity in classification will help to ensure a level playing field and may obviate the need for practices such as boosting to gain an advantage due to poor cardiovascular control.     

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

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）１、舒张压（ＤＢＰ）与阴性组、对照组比较，无显著性差异。试验后，     

用心率变异性谱分析法研究振动性白指患者自主神经系统对冷刺激的反应

目的研究振动性白指患者的自主神经系统对冷刺激的反应。方法２２名振动性白指患者（ＶＷＦ组）及１９名正常对照（对照组）进行了局部冷水刺激实验,记录受试者的心电信号,实验后将记录的心电信号通过处理转化为ＲＲ间期信号,然后对这些ＲＲ间期信号进行功率谱分析,计算标准化的ＬＦ（０．０２～０．１５Ｈｚ）功量（ＬＦ％）,标准化的ＨＦ（０．１５～０．４０Ｈｚ）功量（ＨＦ％）,以及ＬＦ／ＨＦ比率。结果冷暴露开始后,ＶＷＦ组及对照组的ＨＦ％与暴露前的水平相比都有显著下降,ＶＷＦ组的ＬＦ／ＨＦ比率与暴露前的水平相比有显著增大,而且冷暴露中ＶＷＦ组的ＬＦ／ＨＦ比率显著高于对照组的相应的ＬＦ／ＨＦ比率。结论冷刺激导致ＶＷＦ组和对照组的副交感神经活动减弱,但对照组还能保持交感与副交感的平衡,而ＶＷＦ组却不能保持两者平衡,交感神经活动明显占优,冷刺激中ＶＷＦ组ＬＦ／ＨＦ比率明显高于对照组的ＬＦ／ＨＦ比率说明振动性白指患者的交感神经系统对冷刺激可能存在过敏反应。     

夏季低空飞行对飞行人员血浆SOD及红细胞膜总抗氧化能力的影响

目的 探讨夏季低空飞行中座舱复合因素对飞行人员血浆ＣｕＺｎ－ＳＯＤ及红细胞膜总抗氧化能力（Ｔ－ＡＯＣ）的影响。方法 ２４名轰六飞行员为实验组,２１名普通地面人中同为对照组。作多靶场轰炸飞行,飞行高度８００￣１２００ｍ,舱内温度４５￣５３℃,噪声９７￣１２２ｄＢ（Ａ）,飞行时间３．０ｈ,于飞行前（６：００）、飞行后即刻（１２：００）及８ｈ（２０：００）采血。对照组实行日常室内作业（２７℃）,同时采血     

Autonomic modulations of heart rate variability are associated with sports injury incidence in sprint swimmers

Objectives: Young athletes’ participation in competitive sports is becoming increasingly common, and this increased involvement raises concerns about the occurrence of overtraining and sports injuries. Since these issues are poorly understood, this study analyzed heart rate variability, stress/recovery relationship, and sports injury incidence during a training macrocycle of young sprint and endurance swimmers.

Methods: Thirty teenage swimmers (aged 12 to 17 years) were divided into two groups as follows: Sprint (n = 17) and Endurance (n = 13). Subjects were evaluated over 20 weeks, based on the following three schedules: general, specific, and competitive. In addition to heart rate variability and sports injury incidence, the Recovery-Stress-Questionnaire of Athletes was used to analyse stress/recovery states in athletes. All procedures were developed at the initial moment and at the end of each periodization step.

Results: The Sprint group presented a reduced standard deviation of normal-normal beats (73.0 ± 6.6 vs. 54.1 ± 3.5 ms; p < 0.05) and root mean square of the successive differences (55.3 ± 6.2 vs. 42.0 ± 3.7 ms; p < 0.01) from the period of general preparation until the time of competition. Recovery-stress monitoring was affected only by the swimming training periodization (p < 0.05). During the general period, differences between recovery and stress scales were correlated directly with the root mean square of the successive differences (r = 0.576; p = 0.001), the standard deviation of instantaneous variability beat-to-beat (r = 0.521; p = 0.003) and the triangular index (r = 0.476; p = 0.008). Differences between general recovery and stress scales were inversely correlated with geometric indexes after the specific training period. Moreover, the Sprint group showed a higher incidence of sports injury than the Endurance group (0.0214 ± 0.0068 vs. 0.0136 ± 0.0050 cases/1000 hours).

Conclusion: Sprint training was associated with progressive activation of the sympathetic nervous system as well as a higher incidence of sports injury in comparison to endurance swimming during a training macrocycle.     

Assessment of left ventricular volume by an ambulatory radionuclide monitoring system during head-up tilt in patients with unexplained syncope: Relation to autonomic activity assessed by heart rate variability

BACKGROUND: Decreased left ventricular volume during head-up tilt plays an important role in triggering syncope in patients with neurally mediated syncope. However, precise changes in left ventricular volume during head-up tilt have not been well investigated. This study was conducted to test the hypothesis that the decline in left ventricular volume during tilt could trigger ventricular mechanoreceptor activation. METHODS AND RESULTS: To investigate the mechanisms of tilt-induced syncope, we measured the temporal changes in left ventricular volume, ejection fraction, cardiac output, and heart rate variability indices during head-up tilt in 25 patients with syncope of undetermined etiology. Eleven patients had a cardioinhibitory response (CI group), 7 patients showed a vasodepressor response (VD group), and 7 patients demonstrated a negative response (NG group). Before syncope, ejection fraction increased most in the CI group, the left ventricular end-diastolic volume declined most in the VD group (VD group, -11.0% +/- 3.3%; CI group, -2.8% +/- 4.8%; NG group, -3.4% +/- 2.2%; P <.005), and the high-frequency spectra increased most in the CI group (CI group, 25.0% +/- 21.0%; VD group, -4.1% +/- 11.7%; NG group, -5.3% +/- 12.7%; P <.01). The vasodepressor response was dependent on left ventricular volume, whereas the cardioinhibitory response was related to the vagal activity reflected by high-frequency spectra. CONCLUSIONS: The precise evaluation of left ventricular volume by an ambulatory radionuclide monitoring system combined with a heart rate variability analysis is considered useful for clarifying the pathophysiology of neurally mediated syncope.     

下体负压旋转床模拟航空推拉效应对心血管功能的影响

目的探讨下体负压旋转床模拟航空推拉效应的效果 ,观察推拉动作对心血管功能的影响。方法 8名被试者在下体负压旋转床上进行“直立位 (HUT ,+1Gz) -倒立位 -直立位 +下体负压 (LBNP ,- 5 0mmHg) 1 0min”的模拟推拉效应试验及单纯直立位 +下体负压 (- 5 0mmHg) 1 0min的对照试验 ,用阻抗法测量了试验过程中心率 (HR)、血压 (BP)、基础阻抗 (Z0 )、每搏心输出量 (SV)、心输出量 (CO)及总外周阻力 (TPR)等心血管功能指标的变化。结果在模拟推拉效应试验中 ,有 3名被试者没有完成直立位 +LB NP作用 1 0min的试验 ,出现晕厥前症状 ,8名被试者平均耐受时间为 8.99± 1 .47min。而对照试验时 ,被试者均完成了 1 0min的直立 +LBNP试验。模拟推拉效应试验时 ,在倒立位 ,被试者HR、Z0 较直立位对照值降低 ,SV和CO较直立位对照值升高 ,均有显著性意义 ;直立位 +LBNP过程中 ,HR、Z0 、TPR较对照和倒立位值显著增高 ,SV和CO较对照和倒立位值显著降低 ,SBP在HUT即刻较对照值显著性增高 ,在HUT +LBNP过程中显著性降低。在对照试验时 ,上述指标呈现出相同的变化 ,但增高或降低的百分比 (% )低于模拟推拉效应试验 (HR除外 )。结论倒立位后 ,再直立 +LBNP作用 ,心血管功能下降程度大于单纯直立 +LBNP作用 ,下体负压旋转床     

组织多普勒成像评价糖尿病患者左心功能

目的:应用组织多普勒技术探讨糖尿病发展过程中的心肌损害。方法:152例受试者包括确诊为Ⅱ型糖尿病的患者53例(按病程0~5年,5~10年,10~15年和>15年分为4组);糖耐量异常41例,正常对照组58例,均行常规超声检查和组织多普勒心脏功能检查,测量心肌各节段运动速度以评价心肌的收缩和舒张功能,对比分析各组间心肌功能的差异。结果:糖尿病组和糖耐量异常组患者的心肌功能降低,糖尿病患者心肌的受损程度与病程呈正相关(P<0.05)。结论:组织多普勒技术具有较高的敏感性,可将"糖尿病性心肌病"的概念提前。