X综合征与冠心病心率变异性的对比分析

为比较X综合征和冠心病患者心率变异性指标的异同,探讨X综合征自主神经变化的临床意义,选择X综合征患者、冠心病患者、正常对照各12例,测定了时域和频域指标,分析X综合征的心率变异参数,并与冠心病和正常对照组进行对比。结果表明,X综合征组和冠心病组各时段心率变异指标均低于对照组,X综合征与冠心病对比,夜晚RMSSD、清晨LF／HF和VLF差异有显著性（P＜0.05）。提示X综合征患者存在心血管自主神经系统调节功能紊乱现象,以交感神经活动占优势;心率变异分析可作为观察X综合征自主神经变化和指导临床治疗的指标。     

急性缺氧条件下的心率变异性分析

目的 以心率变异性（HRV）为定量评价心血管自主神经调节变化的指标,观察模拟5000m急性缺氧条件下,自主神经变化特点,并探讨预测缺氧耐力不良的方法。方法 被试者为11名18－30岁的健康男性,以呼吸10．5％的低氧混合气30min模拟5000m急性缺氧,以时域和频域（粗粒化谱分析,CGSA）方法进行HRV分析。并根据是否完成实验过程将被试者分为耐力良好组（A组）和耐力不良组（B组）。结果 耐力良好组在缺氧时心率显著增快,相邻RR间期之差的均方根值（RMSSD）显著减小,LFn.u(LF的标准单位）和LF／HF显著增大,HF和HFn.u.(HF的标准化单位）显著减小。两组比较,缺氧5－10min时,LFn.u.和LF／HF在B组显著大于A组,缺氧10－15min时,RMSSD在B组显著小于A组。结论 在模拟5000m急性缺氧条件下,交感神经活动增强,迷走神经活动减弱;HRV分析对评价缺氧耐力有一定的预测性。     

急性缺氧条件下的心率变异性分析

目的：以心率变异性（HRV）为定量评价心血管自主神经调节变化的指标，观察模拟5000m急性缺氧条件下，自主神经变化特点，并探讨预测缺氧耐力不良的方法。方法：被试为11名18－30岁的健康男性，以呼吸10．5％的低氧混合气30min模拟5000m急性缺氧，以时域和频域（粗粒化谱分析，CGSA）方法进行HRV分析，并根据是否完成实验过程将被试分为耐力良好组（A组）和耐力不良组（B组），结果：耐力良好组在缺氧时心率显增快，相邻RR间期之差的均方根值（RMSSD）显减小，LFn.u.(LF的标准化单位）和LF／HF显增大，HF和HFn.u.(HF的标准化单位）显减小，两组比较，缺氧5－10min时，LFn.u.和LF／HF 在B组显大于A组，缺氧10－15min时，RMSSD在B组显小于A组，结论：在模拟5000m急性缺氧条件下，交感神经活动增强，迷走神经活动减弱；HRV分析对评价缺氧耐力有一定的预测性。     

急性轻中度缺氧条件下心率及收缩压变异性谱变化

目的：应用心率及收缩压变异性（HRV、SBPV）谱分析方法评价急性轻中度缺氧条件下心血管自主神经调节的变化。方法：10名健康男性青年分别吸入氧13．7％（相当于海拔3500m)和11％（相当于海拔5000m）两种氮－氧混合气各20min,将对照和缺氧条件下的HRV和SBPV谱变化进行对比分析。结果：在两种缺氧条件下,受试者均出现血压下降、心率增快反应,HRV谱总功率（TP）和高频成分（HF）功率均显著减小,低频成分（LF）功率与LF／HF功率比值无显著变化,SBPV谱LF功率显著增大,3名缺氧耐力不良受试者尤为明显。不同水平缺氧之间的数值比较差异均无显著性意义。结论：急性轻中度缺氧条件下,人副交感神经抑制,交感神经兴奋,联合应用HRV与SBPV谱分析方法可对心血管自主神经调节活动进行评定;但HRV的LF成分变化机理较为复杂。     

硬膜外阻滞对左心室肥厚围术期心率变异性影响的观察

目的：观察上胸段硬膜外阻滞（HEB）对高血压性左心室肥厚围术期心率变异性（HRV）的影响。方法：选择择期行胃部切除术且合并高血压性左心室肥厚40例,随机分为观察组和对照组各20例。对照组采用静吸复合全身麻醉,观察组在对照组基础上加用HEB,分别在入室静卧30min后、清醒拔管后即刻、术后第1天、第3天及第5天,以短时程频域分析法检测HRV变化。结果：麻醉及术后两组HRV总功率（TP）、高频（HF）、低频（LF）和HF/LF均较术前基础值显著下降,术后第5天观察组上述指标基本恢复到术前水平,而对照组除LF外,其余指标仍显著低于术前水平（P〈0.01）。结论：上胸段硬膜外阻滞可减轻高血压性左心室肥厚患者围术期心脏自主神经损害。     

高血压患者夜间心率对24小时心率变异性影响的观察与分析

心率变异(Heart rate variability,HRV)检测分析,作为一种间接评定心脏自主神经功能的手段,逐渐被广泛应用于临床研究。它是近年来检测严重心律失常以及心脏猝死的重要指标。在高血压病中也有预测价值。本文分析了96例高血压患者夜间心率(22:00～7:00)变化对24 h HRV时域指标和频域指标的影响,并探讨其临床意义,现报告如下。     

辛伐他汀对陈旧性心肌梗死患者心脏自主神经功能的影响

目的：观察辛伐他汀对陈旧性心肌梗死（OMI）患者心脏自主神经功能的影响,探讨其治疗价值。方法：20例OMI患者随机分为辛伐他汀组和安慰剂组,每组各10例,治疗前后用数字化24hHolter记录测定心功能时域参数和频域参数。结果：OMI患者用辛伐他汀治疗4周后,心功能各项指标均明显好转,SDNN、LF和HF均明显增加,LF/HF明显降低,差异有显著性（P〈0.05）。结论：辛伐他汀具有降低陈旧性心肌梗死患者交感神经活性,提高迷走神经张力的作用,使交感神经和迷走神经平衡性趋向于正常,提示该药具有稳定OMI患者自主神经功能的作用。     

肺静脉和上腔静脉电隔离后阵发性房颤患者心率变异性变化

目的用心率变异性(HRV)评价电隔离肺静脉(PVs)和上腔静脉(SVC)对阵发性房颤(PAF)患者自主神经功能的影响。方法对21例PAF患者进行心电生理检查(EPS)并电隔离有关PVs和(或)SVC,记录患者术前、术后3d、术后3月24h动态心电图(Holter),分别得到平均窦率(MeanHR)、最大窦率(MaxHR)、时域指标:RR间期标准差(SDNN)、相邻RR间期差的均方根(rMSSD)、频域指标:低频带(LF)、高频带(HF)、低频高频比值(LF/HF),记录每个患者接受电隔离的PVs和(或)SVC支数(Number),计算每个患者电隔离的累计能量(Energy)。结果电隔离PVs、SVC总计63支,左上PV(LSPV)21支,右上PV(RSPV)18支,左下PV(LIPV)16支,SVC8支;与隔离前比较,静脉电隔离后3dMaxHR,MeanHR,LF/HF显著升高,SDNN,rMSSD,LF,HF显著降低,上述各值与电隔离PVs和(或)SVC累计能量多少无明显相关性,SDNN、LF、HF随电隔离的PVs和(或)SVC支数不同而有显著性差异;静脉电隔离后3月MaxHR,MeanHR,SDNN,rMSSD,LF,HF,LF/HF均恢复到电隔离前水平。结论PVs和(或)SVC口部的电隔离能导致PAF患者短时间心率增加、HRV降低,HRV部分指标在电隔离PVs和SVC不同支数组间有显著差别。     

有氧锻炼对心血管自主神经调节的影响

为研究有氧锻炼对心血管自主神经调节的影响,采用动态心电、血压监测技术,对6名男性中长跑运动员和7名健康男性大学生6个月长跑训练(20～25km/周)前后的下体负压(LBNP)耐力,Valsalva动作的心率、血压反应,心率变异性(HRV),血压变异性(SBPV)以及自发性压力感受器-心率反射反应的斜率(BRS)进行了测量.结果表明,有氧锻炼可以导致LBNP耐力降低,Valsalva动作Ⅱ期舒张压恢复幅度与最大心率值显著减小,平卧位HRV谱总功率(TP)、低频(LF)与高频(HF)成分功率呈减小变化,平卧位SBPV谱TP、LF成分功率与平均自发性BRS值减小,LBNP作用下HRV谱LF/HF值明显增大.说明有氧锻炼可导致心血管自主神经调节功能下降,可考虑将上述有关指标变化用于监测有氧锻炼强度以及个体敏感性,更科学地对有氧锻炼进行卫生指导.     

民航飞行人员高血压病危险因素与心率变异性及压力反射敏感度的联系

目的：探讨民航飞行人员高血压病危险因素暴露与心率变异性（HRV）及压力反射敏感度（BRS）之间的联系。方法：在参加年度大体检的450名血压正常的民航飞行人员中,根据有无危险因素暴露将其分为年龄≥40岁组、体重超重组、血胎异常组、吸烟组、饮酒组及相应对照组。采用常规自回归谱分析方法对各组飞行人员的短时程HRV信号进行分析,同时采用序贯法计算其BRS。结果：与对照组相比,年龄≥40岁的飞行人员HRV明显降低,表现为总功率（TP）、低频功率（LF）、高频功率（HF）及归一化高频成分（HFn）显著降低（P＜0．01）,而归一化低频成分（LFn)与LF／HF则显著增加（P＜0．05）;其BRS亦显著降低（P＜0．01）。其他危险因素暴露时,HRV的TP、LF及HF均显著降低（P＜0．05）,而LFn、HFn及LF／HF则无明显变化,BRS亦显著降低（P＜0．05）。结论：民航飞行人员高血压病危险因素的暴露与HRV及BRS的降低密切联系;提示在高血压病发病之前,心血管自主神经调节功能即已发生异常。在对飞行人员进行高血压病的早期危险性预报时应重视对其自主神经调节功能的评价。     

心率变异性与运动病关系的研究

目的　探讨心率变异性与运动病的关系。方法　根据出海实习学员运动病的发生情况 ,将学员分为运动病组和对照组各 2 0人 ,采集安静状态下的 5 2 0次窦性心搏 ,应用心率变异时域、频域分析方法评价自主神经功能状态。结果　运动病组时域指标 RR间期平均值的标准差 (SDNN)、相邻 RR间期差值的均方根 (r MSSD)、相邻 RR间期相差大于 5 0 m s占总心动周期数的百分比 (PNN50 )、HRV指数(HRVI)和频域指标低频 (L F)、高频 (HF)、总功率谱密度 (TP)均显著高于对照组 (P<0 .0 5 )。 RR间期平均值 (MRR)、极低频 (VL F)、低频与高频的比值 (L F/ HF)在两组间差异无显著性 (P>0 .0 5 )。结论　自主神经功能状态对运动病的发生存在明显的影响 ,迷走神经张力过高与运动病的发生有密切关系。心率变异性检测可以作为运动病易感性重要的预测指标。     

跨时区飞行对飞行员心率变异性的影响

目的　探讨跨时区飞行对飞行员心率变异性的影响 ,以评价其对飞行员自主神经系统的作用。　方法　采用 2 4h动态心电图方法检测 16名跨时区国际长途飞行的飞行员动态心电图及心率变异性 (HRV) ;另外检测 10名国内昼间飞行的飞行员动态心电图及HRV作为对照。检查指标 :①HRV的低频功率 (0 .0 4～ 0 .15Hz ,LF) ;②HRV的高频功率 (0 .15～ 0 .4 0Hz,HF) ;③HRV的总频功率 (0 .0 4～ 0 .4 0Hz,TF)。计算飞行员HRV谱成份的夜间调节指数。用两组飞行员调节指数的差值作为自主神经负荷程度的定量估计。　结果　对照组飞行员的HF反映迷走神经活性在 2 4h中显示明显的昼夜节律 ,即夜间HF增高 ,LF降低 ;白天HF降低 ,LF增高。交感神经活性在跨时区飞行组上述谱成份的昼夜节律性明显降低。②对照组飞行员的HF夜间调节指数为 0 .32± 0 .11,而跨时区飞行组HF夜间调节指数为 0 .0 6± 0 .0 2 (P <0 .0 5 )。对照组LF夜间调节指数为 - 0 .0 2± 0 .0 8,而跨时区飞行组LF夜间调节指数为 - 0 .0 9± 0 .0 4 (P <0 .0 5 )。　结论　跨时区飞行使飞行员HRV谱成份的昼夜周期节律显著降低     

老年特发性阵发性心房颤动患者的自主神经功能分析

目的　观察老年特发性阵发性心房颤动 (IPAF)患者心率变异性 (HRV)的变化 ,以此评价自主神经功能的变化在老年IPAF发作中的作用。方法　选取我院住院的未服用抗心律失常药物的老年IPAF患者 2 4名和无心律失常病史的老年人 2 4名进行 2 4h动态心电图检测和HRV分析。结果　和对照组相比 ,IPAF组LF/HF增高 ,其余各指标均有不同程度降低 ,其中SDNN(P <0 .0 1)、SDANN(P <0 .0 1)和LF/HF(P <0 .0 5 )统计学差异有显著性意义。结论　老年IPAF患者的HRV降低 ,提示心脏自主神经系统功能紊乱在老年患者IPAF的发作中起重要作用。     

Effects of aerobic exercise training on 24 hr profile of heart rate variability in female athletes

BACKGROUND: The aim of this study was to investigate the effects of exercise training on autonomic regulation of heart rate under daily life conditions. METHODS: Twenty-six healthy female athletes (age 24.5 +/- 1.9 yrs) involved in regular physical activity were recruited during a period of yearly rest and randomly assigned to a five-week aerobic exercise training program (n = 13) or to a non-exercise control group (n = 13). MEASURES: Before and after the five-week training, all subjects underwent a bycicle ergometer stress test and a 24-hour dynamic ECG monitoring. Autonomic regulation of heart rate has been investigated by means of both time and frequency domain analyses of heart rate variability (HRV). Spectral analysis of R-R interval variability (autoregressive algorithm) provided markers of sympathetic (low frequency, LF, 0.10 Hz) and parasympathetic (high frequency, HF, 0.25 Hz) modulation of the sinus node. RESULTS: Trained subjects showed a reduced heart rate response to submaximal workload. Before training there was no significant difference between the two groups. After training resting heart rate did not significantly differ between trained and untrained subjects. No significant differences were observed in the different time domain indexes of heart rate variability. The day-night difference in SD and SDRR were significantly less in the trained as compared to the untrained group. Normalized LF and HF components did not significantly differ between trained and untrained subjects, during the awake period. The decrease in the LF and the increase in the HF component during nighttime were significantly less in the trained group. The LF/HF ratio was significantly decreased during the night in the untrained group whereas it was not significantly different from the awake state in the trained group. CONCLUSIONS: These findings of the relative night-time increase in LF and the decrease in the day-night difference in time domain indexes of heart rate variability suggest that, in young female athletes, exercise training is able to induce an increase in the sympathetic modulation of the sinus node which may coexist with signs of relatively reduced, or unaffected, vagal modulation.     

Evaluation of the effect of flights in supersonic fighters on sinus rhythm variability parameters

Heart rate variability is a widely used method to evaluate vagal and sympathetic influences on the heart. The purpose of this study was to assess the relationship of autonomic nervous system components' interaction in supersonic fighter pilots by means of a sinus rhythm variability analysis. The following frequency domain parameters were analyzed: low-frequency (LF) power spectral of 0.05 to 0.15 Hz (ms2); high-frequency (HF) power spectral of 0.15 to 0.45 Hz (ms2); LF and HF power spectral index; total spectral power (HF + LF); percent, LF distribution in total spectral power; percent HF, HF distribution in total spectral power; and an average heart rate per minute. The study comprised 30 healthy military pilots (age, 24-48 years) in whom heart rate variability parameters were determined 10 to 12 minutes before take off, 10 to 12 minutes after four successive flights, and 1, 2, and 12 to 16 hours after completing the flights. The control group was comprised of 20 healthy nonpilots (age, 24-49 years). The statistical significance was estimated by means of the following methods: Student's t test for normal distribution and a rank test for the non-normal one (between the groups of the same subjects); and the Cochran-Cox test for normal distribution and the Wilcoxon test for the non-normal one (between the groups of different subjects). Higher activity of sympathetic components of the autonomic nervous system was shown in pilots in the course of the first examination before flights as compared with the controls (higher LF, LF/HF, percent LF). Predominance of the sympathetic nervous system in pilots might reflect adaptation to repeated short-term exposures to high values of accelerations acting in head-leg axis.     

前庭刺激对飞行人员心率变异的影响

为探讨前庭刺激对飞行人员的心率变异性（ＨＲＶ）及植物神经功能的影响，对两组飞行员在不同强度的科里奥利加速度刺激时，用时域分析和频域分析法对实验前和实验中的ＨＲＶ进行了检测和分析。结果表明；原始均值，标准差，最小值，最大值，极差，相关均值，Ｒ－Ｒ间期差值的均方根（ＲＭＳＳＤ），谱总功率（ＴＰ），低频（ＬＦ），高频（ＨＦ），ＬＦ／ＴＰ，ＨＦ／ＴＰ，ＬＦ／ＨＦ均有不同程度的增加（Ｐ〈０．０５～０．０１）     

心率变异时域对老年慢性心力衰竭预后危险分级的定量研究

目的 检测老年慢性心力衰竭（CHF）患者的心率变异（HRV）时Ⅱ定量指标SDNN、SDANN 、RMSSD、三角指数,观察其与CHF病情的相关性及临床价值。方法分别选取80例老年CHF患者和50例无心衰老年受试者,测定HRV时Ⅱ指标,对两组间检测结果进行对比分析,并观察HRV与心功能NYHA分级的关系。结果观察组HRV时Ⅱ指标明显低于对照组（P〈0.05）,根据NYHA分级Ⅲ～Ⅳ级患者的各项时Ⅱ指标均显著低于Ⅰ～Ⅱ级患者（P〈0.05）。结论 HRV的变化与老年CHF患者的心功能损害程度密切相关,监测心率变异的变化,对于老年CHF患者病情的评价及预后有积极意义。     

老年人原发性高血压血压晨峰与心率变异性及心脏重构关系的探讨

 目的 探讨老年人原发性高血压血压晨峰(morning blood pressure surge, MBPS)与心率变异性(heart rate variability ,HRV)及心脏重构的关系.方法 将明确诊断的老年人原发性高血压51例行动态血压监测、动态心电图监测(Holter)及超声心动图检查.根据MBPS程度是否超过50 mmHg(1 mmHg=0.133 kPa)分为MBPS≥50 mmHg组(A组)和MBPS＜50 mmHg组(B组),将两组患者的临床情况、HRV、左心室肥厚(left ventricular hypertrophy ,LVH)及室性心律失常等指标进行比较.结果 两组患者临床情况比较差异无统计学意义(P＞0.05);A组低频功率/高频功率(LF/HF)比值、LF值高于B组(P＜0.01和P＜0.05);A组LVH及室性心律失常发生率高于B组(P＜0.05).结论 老年人原发性高血压MBPS程度加剧与HRV及心脏重构有密切关系,是发生心脏事件的重要因素.     

Heart period variability in trauma patients may predict mortality and allow remote triage

INTRODUCTION: The high frequency to low frequency ratio (HF/LF) derived from analysis of heart period variability is elevated and associated with mortality in severely injured patients monitored in a hospital. The purpose of this study was to test the utility of heart period variability measurements as indicators of injury severity in patients prior to definitive medical intervention. We tested the hypothesis that survival is associated with low relative HF/LF, and death is associated with high relative HF/LF. METHODS: We performed retrospective analyses of 84 pre-hospital trauma patient records (n=42 non-survivors; n=42 survivors) collected during helicopter transport to a Level 1 urban trauma center. R-waves from 2-min segments of ECG waveforms were converted to the frequency domain with a Fourier transform. Spectral power was separated into low (LF; 0.04-0.15 Hz) and high (HF; 0.15-0.4 Hz) frequency bands for analysis and derivation of frequency ratios. RESULTS: Absolute HF, LF, and HF/LF were not distinguishable statistically between groups (p > or = 0.26), but HF/LF was higher (p = 0.04) for non-survivors (140 +/- 26) than survivors (74 +/- 19). After normalization to account for large intersubject variability, HFnu (43 +/- 3 vs. 28 +/- 2) and HF/LFnu (248 +/- 50 vs. 73 +/- 19) were higher (both p < 0.001), and LFnu (42 +/- 4 vs. 64 +/- 3) was lower (p = 0.0001) for non-survivors [19 h (median) before death] compared with survivors. CONCLUSIONS: Our results show that heart period variability analyses separate patients who die from patients who survive traumatic injury. We propose that such analyses could be employed for remote triage of injured patients in austere environments.     

Heart rate variability in sportive elderly: relationship with daily physical activity

PURPOSE: Aging is associated with decreased heart rate variability (HRV). As aerobic training is known to increase HRV, the purpose of this study was to evaluate the influence of long-term lifestyle on HRV in very old adults with regard to their usual physical activity. METHODS: Twenty-four older adults (mean 75.7 +/- 0.2 yr) were divided into two groups according to their sport activities assessed by the Modified Baecke Questionnaire for Older Adults. Sedentary subjects (SED) were compared to elderly regularly involved in sport activities (SP). The subjects were supine for 20 min and the last 5 min were used to determine HR and HRV indexes as the standard deviation of normal intervals (SDNN), the root-mean-square differences of successive normal R-R intervals (RMSSD), and the high-frequency (HF) and low-frequency (LF) power. Physical activity was evaluated during 1 wk by triaxial accelerometry and analyzed in terms of intensity and duration. RESULTS: Daily physical activity energy expenditure given by the accelerometer was significantly higher in SP than in SED (P < 0.05). SP spent more time per week in activity of intensity higher than 3 resting metabolic equivalents (METs), but total activity time was significantly higher for SED than for SP (P < 0.05). SP showed significantly (P < 0.05) lower resting heart rate than SED, higher global HRV (SDNN), and higher parasympathetic-related HRV indexes (RMSSD, HF, and HF/(LF+HF)) (P < 0.05). CONCLUSIONS: Our results indicate that in very old subjects a long-term sportive lifestyle, which increases total daily energy expenditure and physical activity intensity, is associated with higher global HRV and vagal-related indexes and thus may counteract the age-related decline in cardiac autonomic control better than a sedentary lifestyle.