40岁以上正常人的心率变异分析

报告５０例正常人的心率变异分析。按参数间密切相关将６项频域、１０项时域参数分成三组：总频成分（ＴＯＴ）、超低频成分（ＵＬＦ）、极低频成分（ＶＬＦ）、连续５ｍｉｎ正常Ｒ－Ｒ间期标准差均值（ＡＳＤ）；高频成分（ＨＦ）、相邻正常Ｒ－Ｒ间期差值均方根（ＲＭＳＳＤ）、相邻正常Ｒ－Ｒ间期超过５０ｍｓ正常Ｒ－Ｒ间期均值的标准差（ＳＤＡ）、ＳＤＡ的心率较正值（ＳＤＡＣ）。健康男性ＳＤ显著高于女性，女性ＲＭＳＤＣ显     

40岁以上正常人的心率变异分析

报道５０例正常人的心率变异分析。按参数间密切相关将６项频域、１０项时域参数分成三组：总频成分（ＴＯＴ）、超低频成分（ＵＬＦ）极低频成分（ＶＬＦ）、连续５ｍｉｎ正常Ｒ－Ｒ间期标准差均值（ＡＳＤ）；高频成分（ＨＦ）、相邻正常Ｒ－Ｒ间期差值均方根（ＲＭＳＳＤ）、相邻正常Ｒ－Ｒ间期超过５０ｍｓ的百分比（ＰＮＮ５０）、ＲＭＳＳＤ心率校正值（ＲＭＳＤＣ）及正常Ｒ－Ｒ间期标准差（ＳＤ）、ＳＤ心率校正值（ＳＤＣ）、连续５ｍｉｎ正常Ｒ－Ｒ间期均值的标准差（ＳＤＡ）、ＳＤＡ的心率校正值（ＳＤＡＣ）。健康男性ＳＤ显著高于女性，女性ＲＭＳＤＣ显著高于男性。各参数随年龄增长而变小，年龄与低频成分（ＬＦ）和ＡＳＤＣ（ＡＳＤ的心率校正值）相关最密切（ｒ分别为－０．６５和－０．６１），其次与ＲＭＳＤＣ、ＰＮＮ５０、ＨＦ、ＶＬＦ、ＲＭＳＳＤ、ＴＯＴ、ＡＳＤ、ＳＤＣ、ＳＤ等呈显著负相关（Ｐ＜０．０５）。心率与ＴＯＴ、ＵＬＦ、ＶＬＦ、ＳＤ、ＡＳＤ、ＲＭＳＳＤ等呈负相关（Ｐ＜０．０５）。多项参数有明显昼夜规律。     

犬心率变异的实验研究

为了解正常犬心率变异（ＨＲＶ）的特征，以便在此基础上作各种病理模型的前瞻性ＨＲＶ研究。取健康成年杂种犬２０只，自由活动下记录２４ｈ心电图。ＨＲＶ分析采用时域、频域分析方法及构制２４ｈ三维频谱图及Ｐｏｉｎｃａｒｅ散点图。结果：２０只犬２４ｈ总心搏数为１３４６５２．６１±１６１９．３１次，平均心率为１０８．００±１６．６１ｂｐｍ。正常ＲＲ间期标准差（ＳＤＮＮ）、连续５ｍｉｎ正常ＲＲ间期标准差均值（ＳＤＡＮＮ）、连续５ｍｉｎ正常ＲＲ间期均值的标准差（ＳＤＮＮｉ）、相邻正常ＲＲ间期差值的均方根（ｒＭＳＳＤ）、相邻正常ＲＲ间期超过５０ｍｓ的百分比（ＰＮＮ５０）分别为１０８．００±４５．１１ｍｓ、９５．００±４３．８１ｍｓ、４１．４５±１８．０５ｍｓ、１９９．００±５４．４１ｍｓ、５６．００±１３．９４％。超低频成分（ＵＬＦ）、极低频成分（ＶＬＦ）、低频成分（ＬＦ）、高频成分（ＨＦ）、ＬＦ／ＨＦ分别为３８．００±３３．７６ｂｐｍ２／Ｈｚ、６１．００±４０．５８ｂｐｍ２／Ｈｚ、２７８．００±１６４．１７ｂｐｍ２／Ｈｚ、２７８．００±１９６．６０ｂｐｍ２／Ｈｚ、１．７３±２．５９。ｒＭＳＳＤ、ＨＦ等反映ＲＲ间期快速变化的成?     

慢性充血性心力衰竭患者心率变异分析

分析２６例充血性心力衰竭患者（心衰组）、１７例心功能代偿的心血管病患者（心功代偿组）和４２例正常人（正常组）的心率变异（ＨＲＶ）时域指标。连续记录２４小时的动态心电图，通过计算机人为确认窦性心搏后，由计算机自动算出各ＨＲＶ指标。结果显示心功能代偿组２４小时窦性Ｒ－Ｒ间期标准差、５分钟窦性Ｒ－Ｒ间期均值的标准差和５分钟窦性Ｒ－Ｒ标准差的均值均较正常组显著下降（Ｐ＜０．０１、０．０５和０．０５），Ｒ－Ｒ连续差异平方根和相邻窦性Ｒ－Ｒ间期差值＞５０ｍｓ的百分比虽低于正常组，但无显著差别（Ｐ＞０．０５）；心衰组的上述各指标均显著低于正常组（均Ｐ＜０．００１）；心衰组和心功代偿组相比，前３个参数均显著降低于对照组（Ｐ＜０．００１），后２个参数有下降但不显著（Ｐ＞０．０５）。将心衰组分为Ⅲ度（ｎ＝１０）和Ⅱ度心衰（ｎ＝１６）两个亚组，结果发现心衰Ⅲ度组的上述各指标明显低于Ⅱ度组（Ｐ＜０．００１～０．０５）。提示部分心血管病患者在心功代偿期时自主神经的平衡已受到损害，当出现心衰时交感活性进一步增强，迷走张力下降。ＨＲＶ时域指标可作为判断心衰严重程度的参数，其对心衰患者生存率的预后价值有待进一步研究。     

老年急性心肌梗塞心率变异时域分析

目的分析急性心肌梗塞（ＡＭＩ）后老年患者心率变异（ＨＲＶ）时域指标，了解ＡＭＩ后ＨＲＶ变化。方法以多单位协作方式对１５７例ＡＭＩ后２周的老年患者行动态心电图检测ＨＲＶ时域法５项指标，并与健康老年组对比分析。数据经ＥｐｉＩｎｆｏ（６．０）统计软件处理。结果①ＡＭＩ患者的正常Ｒ－Ｒ间期标准差（ＳＤＮＮ）、平均值的标准差（ＳＤＡＮＮ）和标准差的平均值（ＳＤＮＮＩｎｄｅｘ）低于对照组（Ｐ＜０．０１），而相邻正常Ｒ－Ｒ间期差值的均方根（ＲＭＳＳＤ）和相邻正常Ｒ－Ｒ差值大于５０ｍｓ记数占总Ｒ－Ｒ间期数的百分比（ＰＮＮ５０）虽低于对照组，但无显著差异（Ｐ＞０．０５）。②ＡＭＩ后ＨＲＶ时域５项指标男、女性别间无显著性差异（Ｐ＞０．０５）。③ＳＤＮＮ、ＳＤＡＮＮ和ＳＤＮＮＩｎ－ｄｅｘ在心肌梗塞各部位间无显著差异（Ｐ＞０．０５），ＲＭＳＳＤ和ＰＮＮ５０前间壁低于下壁心肌梗塞（Ｐ＜０．０５）。结论老年人ＡＭＩ后ＨＲＶ降低。反映交感神经活性的ＳＤＮＮ、ＳＤＡＮＮ和ＳＤＮＮＩｎｄｅｘ和反映迷走神经活性的ＲＭＳＳＤ和ＰＮＮ５０２组指标变化不相同。     

健康老年人和老年心衰,糖尿病患者心率变异性的初步分析

应用动态心电图仪，定量观察了６０例健康人（其中青年及老年人各３０例）、３０例老年心衰患者、３０例老年糖尿病患者的心率变异性。结果显示：健康老年人２４小时正常Ｒ－Ｒ间期标准差（ＳＴＳＤ）为１２３．５±１８．８ｍｓ，２４小时内连续５分钟节段正常Ｒ－Ｒ间期标准差的平均数（ＳＤ）为４５．４±１１．３ｍｓ，２４小时内连续５分钟节段平均正常Ｒ－Ｒ间期标准差（ＳＤＡＮＮ）为１１２．３±１８．３ｍｓ，２４小时内每２个相邻Ｒ－Ｒ间期大于５０ｍｓ的绝对数（ＲＲ_（５０））为５６６６．６±６２４９．２，低频频域测量（ＬＦＰＳＤ）５４４．２±２８６．４ｍｓ￣２／Ｈｚ，高频频域测量（ＨＦＰＳＤ）９０．７±１２１．２ｍｓ￣２／Ｈｚ，均明显低于青年人（Ｐ＜０．００１）。老年心衰患者的ＨＲＶ明显低于健康人，两组间的ＳＴＳＤ、ＳＤ、ＳＤＡＮＮ、ＬＦＰＳＤ比较，差异有显著性（Ｐ＜０．００１）；糖尿病患者ＳＴＳＤ、ＳＤ，ＳＤＡＮＮ，ＬＦＰＳＤ均明显低于健康人（Ｐ＜０．０１）。提示心率变异性可作为判断老年人糖尿病、心衰等预后的手段之一。     

早搏对急性心肌梗死患者心率变异的重复性及稳定性的影响

通过对４７例急性心肌梗死（ＡＭＩ）患者进行连续４８ｈ心电记录,并重复长程心电图ＨＲＶ时域及频域分析,以了解房性早搏（ＡＰＢ）、室性早搏（ＶＰＢ）对ＨＲＶ重复性和稳定性的影响。以ＡＰＢ与ＶＰＢ之和达５次／ｈ为界划分Ⅰ组（早搏＜５次／ｈ,ｎ＝３２,２４ｈ内ＡＰＢ３１．５±３３．９次、ＶＰＢ１１．３±２０．２次）及Ⅱ组（早搏≥５次／ｈ,ｎ＝１５,２４ｈ内ＡＰＢ１０３．８±１５１．６次、ＶＰＢ１５３．１±２５７．２次）,按常规方法进行ＨＲＶ各指标比较分析。结果总体上两组ＨＲＶ时域及频域指标均具有重复性。Ⅰ组反映高频心率波动的指标,如单位时间内连续的窦性ＲＲ间期差的均方根、单位时间内相邻窦性ＲＲ间期差值大于５０ｍｓ所占的百分比（ＰＮＮ５０）、高频带（ＨＦ）（ｒ分别为０．７６,０．７３,０．８９）,以及低频带与高频带比值（ｒ＝０．９３）重复检测相关性明显较Ⅱ组高（ｒ分别为０．３４,０．５９,０．６４,０．３０）。Ⅰ组除单位时间内连续５ｍｉｎ窦性ＲＲ间期标准差的均数、ＰＮＮ５０外各时域指标相对误差（ＲＥ）均值（０．１０～０．１８）及频域指标ＲＥ均值（０．２０～０．３４）均低于Ⅱ组。Ｗｉｌｃｏｘｏｎ检验两组各项指标重复检测?     

心率变异性检测对老年心肌梗死患者预后的临床意义

目的探讨心率变异性（ＨＲＶ）检测对老年心肌梗死（心梗）患者预后的临床意义。方法测定心梗组１０２例和健康对照组３０例的ＨＲＶ时域６项指标,并作对比分析。结果心梗患者平均Ｒ－Ｒ间期标准差的均值（ＳＤ）、ＳＤ的标准差（ＳＤＳＤ）、相邻Ｒ－Ｒ间期差值均方根的均值（ｒｍＳＡＳＤ）低于健康人,分别为（３２±１４）ｍｓ比（４３±１７）ｍｓ、（１１±７）ｍｓ比（１５±７）ｍｓ和（２０±１０）ｍｓ比（２８±１８）ｍｓ（依次为Ｐ＜０．０１、Ｐ＜０．０５、Ｐ＜０．０５）;心梗后心源性死亡者ＳＤ低于存活者〔（２５±１３）ｍｓ比（３３±１３）ｍｓ,Ｐ＜０．０５〕,其中多壁心梗死亡者ＳＤ更低于单壁死亡者〔（１６±３）ｍｓ比（２０±３）ｍｓ,Ｐ＜０．０５〕。结论心梗对ＨＲＶ有明显影响,ＨＲＶ可作为确定心梗危险分层和预测心梗预后的一个指标,定期检测ＨＲＶ对判断心梗预后有一定的临床价值。     

心率变异时域分析对糖尿病患者自主神经功能的评价

采用２４小时动态心电图对８２例糖尿病患者进行心率变异（ＨＲＶ）和心率（ＨＲ）检测。８２例分为五组：Ａ组（无血管合并症）３０例、Ｂ组（合并大血管病变）１１例、Ｃ组（合并小血管病变）１２例、Ｄ组（同时合并大、小血管病变）１９例和Ｅ组（心肾功能不全）１０例，并设正常对照组。结果：糖尿病各组ＨＲＶ显著降低，Ａ组仅２４ｈ内全部正常ＲＲ间期标准差（ＳＤＮＮ，１０４．２０±２９．１９ｍｓ）和２４ｈ内５ｍｉｎ节段平均正常ＲＲ间期的标准差（ＳＤＡＮＮｉｎｄｅｘ，９３．７３±２７．５８ｍｓ）降低（对照组分别为１２７．５２±３８．５７ｍｓ和１１６．１９±３５．７０ｍｓ），Ｐ均＜０．０１；ＨＲ异常主要表现为夜间平均ＨＲ增快，白昼平均ＨＲ仅Ｅ组（８６．７６±１１．３６ｂｐｍ）高于对照组（７６．３８±９．４０ｂｐｍ），Ｐ＜０．０１。表明糖尿病患者存在自主神经受累，白昼心率增快可能是病情严重的征兆。     

缺血性心脏病患者心率变异性研究

应用Ｈｏｌｔｅｒ，测定４０～４９，５０～５９，６０～６９以及７０岁以上４个年龄段的缺血性心脏病患者的心率变异性（ＨＲＶ）并与相应年龄的对照组进行比较，指标为时域法的２４ｈ平均正常Ｒ－Ｒ间期标准差（ＳＤＮＮ）。结果：缺血组与对照组各年龄段比较有显著性差异，分别为：１４１．５２±２８．９２ｍｓＶＳ９３．７２±２７．５４ｍｓ；１３２．４２±２７．６３ｍｓＶＳ９３．１９±３３．１８ｍｓ；１２１．８４±２７．８７ｍｓＶＳ７４．５０±２４．０１ｍｓ；１１０．３１±２３．９６ｍｓＶＳ６３．９３±２３．７３ｍｓ，Ｐ均＜０．０１；对照组及缺血组的ＨＲＶ均随年龄增长呈下降趋势（组内比较，Ｐ均＜０．０１），呈完全负相关（ｒ（对照组）＝－０．９５，ｒ（缺血组）＝－０．９８）。随访发现缺血组中ＨＲＶ≤５０ｍｓ患者发生心源性猝死（ＳＣＤ）９例和室性心动过速１例；＞５０ｍｓ者发生ＳＣＤ２例。     

非持续性室性心动过速患者的心率变异性特点

目的目前有研究发现,室性心动过速（VT）的发作常常伴有低频成分的损害,并且有动态性改变.本文研究非持续性室性心动过速（NSVT）患者心率变异性（HRV）的改变,以期揭示自主神经系统状态与NSVT的关系.方法选择记录有NSVT的动态心电图96份,按有无心脏病分为：无器质性心脏病组（A组）56例,有器质性心脏病组（B组）40例,另选30例正常人作对照组（C组）.分析各组24h HRV以及NSVT发作前2 h和15 min HRV.结果NSVT患者较正常人的HRV时域、频域均降低.B组24 h TP、LFP、LFP/HFP均较A组降低,其LFP的动态改变为在NSVT发作前2 h下降,而在15 min前明显升高;而A组NSVT发作前2 h稍升高,到15 min前明显下降.结论NSVT患者的HRV呈总体降低趋势,但在NSVT发作前低频部分的动态改变会有所不同.有器质性心脏病的NSVT患者其心率变异低频成分LFP较低,而在VT发作前会增高,与无器质性心脏病不同.在不同HRV背景下LFP的反应不同可能是器质性心脏病自主神经功能受损的一种表现.     

肾脏病患者心率变异性的临床分析

目的 :用心率变异性 （HRV）观察肾脏病及肾功不全患者变化。方法 :选择肾功正常的肾病患者 2 6例 ,肾功不全患者 34例 ,正常对照组 34例。用 2 4h动态心电图分析其 HRV的时域指标。结果 :肾功正常肾病组平均 RR间距期 （RR I）、2 4h窦性 R- R间期标准差 （SD）、5 min窦性 R- R间期标准差 （SDAIDX）显著低于正常组 （P<0 .0 5 ） ;肾功不全组 6项指标均明显低于正常对照组 ,SD,5 min窦性 R- R间期标准差的均值 （SDIDX） ,SDAIDX,及 R- R连续差异均方根 （r MSSD）显著低于肾功正常组。结论 :肾脏病患者在肾功正常期即有自主神经功能损伤 ,以交感神经活动受损主为 ;肾功不全患者交感神经及迷走神经功能均受损     

Impact of bariatric surgery--induced weight loss on heart rate variability

Obesity is associated with an increased risk of sudden death that may be due to abnormal cardiac vagal modulation reflected by reduced heart rate variability (HRV). Few studies have been conducted analyzing the effect of bariatric surgery-induced weight loss on HRV assessed by 24-hour Holter monitoring. The aim of this study was to assess weight loss effect after bariatric surgery on HRV and ventricular size and function. Ten morbidly obese patients, 6 women and 4 men aged 24 to 47 years, underwent bariatric surgery. Seven morbidly obese patients without active obesity treatment were used as controls. Twenty-four-hour Holter monitoring and echocardiogram were obtained before and at 6 to 12 months after surgery or at follow-up in control patients. Changes in minimal, maximal, and mean heart rate along with HRV during daytime and nighttime were compared before and after surgery. Baseline characteristics in the control group did not differ significantly from the treatment group. Average weight in the treatment group was 141 +/- 31 kg (mean +/- SD) at baseline and decreased to 101 +/- 18 kg at follow-up, corresponding to a body mass index of 52.3 +/- 7.6 kg/m(2) at baseline and 37.7 +/- 5.3 kg/m(2) at follow-up. There was a decrease in minimal heart rate (48 +/- 10 vs 40 +/- 6 beats per minute, P = .021) and mean heart rate (82 +/- 7 vs 66 +/- 10 beats per minute, P < .001) during the Holter monitoring. Spectral analysis showed a significant enhancement in HRV parameters (high- and low-frequency power) because there was an increase in the standard deviation of normal to normal R-R intervals (116 +/- 25 vs 174 +/- 56 milliseconds, P < .001), the standard deviation of the mean R-R intervals calculated over a 5-minute period (104 +/- 25 vs 148 +/- 45 milliseconds, P < .001), the square root of the mean of the squared differences between adjacent normal R-R intervals (25 +/- 8 vs 50 +/- 20 milliseconds, P < .001), and the percentage of differences between adjacent normal R-R intervals exceeding 50 milliseconds (5% +/- 5% vs 22% +/- 13%, P < .001). Echocardiographic measures remained unchanged when comparing the groups. Weight loss after bariatric surgery enhances HRV and decreases mean and minimal heart rate during Holter monitoring through a better cardiac parasympathetic modulation.     

Cardiac autonomic tone and its relation to nonsustained ventricular tachyarrhythmias in idiopathic dilated cardiomyopathy

BACKGROUND: In contrast to postinfarct patients, little is known about cardiac autonomic tone and its relation to spontaneous ventricular tachyarrhythmias in idiopathic dilated cardiomyopathy (IDC). Both heart rate variability (HRV) and baroreflex sensitivity (BRS) are indices of autonomic innervation of the heart. HYPOTHESIS: The aim of the present study was to determine the relation between cardiac autonomic tone assessed by HRV and BRS and spontaneous nonsustained ventricular tachycardia (NSVT) on Holter in a large patient population with IDC. METHODS: 24-h digital Holter recordings including HRV analysis and BRS testing were prospectively performed in 137 patients with IDC and preserved sinus rhythm. Mean age was 48 +/- 12 years, and mean left ventricular (LV) ejection fraction was 32 +/- 9%. The HRV analysis on Holter included the mean RR interval (RRm), the standard deviation of all normal RR intervals (SDNN), the square root of the mean of the squared differences between adjacent normal RR intervals (rMSSD), and the proportion of adjacent normal RR intervals differing more than 50 ms (pNN50). Testing for BRS was performed noninvasively using the phenylephrine method. RESULTS: Of 137 study patients, 42 (31%) had spontaneous NSVT on 24-h Holter. Compared with patients without NSVT, patients with NSVT on Holter had a higher New York Heart Association (NYHA) functional class (NYHA III: 40 vs. 18%, p < 0.01), a lower ejection fraction (29 +/- 9 vs. 34 +/- 9%, p = 0.01), and an increased LV end-diastolic diameter (69 +/- 8 mm vs. 66 +/- 7 mm, p = 0.03). The HRV variables rMSSD, pNN50, RRm, and BRS did not differ significantly between patients with and without spontaneous NSVT. Only SDNN on Holter was slightly lower in patients with versus without NSVT (106 +/- 45 vs. 121 +/- 46 ms, p = 0.08). CONCLUSIONS: Patients with IDC and spontaneous NSVT on Holter are characterized by a higher NYHA functional class, a lower LV ejection fraction, an increased LV end-diastolic diameter, and a tendency toward a lower SDNN value compared with patients without NSVT. The remaining measures of HRV including rMSSD and pNN50 reflecting primarily tonic vagal activity, as well as BRS reflecting predominantly reflex vagal activity, were similar in patients with and without NSVT. The prognostic significance of these findings in patients with IDC is currently under investigation in the Marburg Cardiomyopathy Study (MACAS) at our institution.     

Changes in Autonomic Activity Preceding Onset of Nonsustained Ventricular Tachycardia

Background: The triggering role of the autonomic nervous system in the initiation of ventricular tachycardia has not been established. To investigate the relationship between changes in autonomic activity and the occurrence of nonsustained ventricular tachycardia (NSVT) we examined heart rate variability (HRV) during the 2-hour period preceding spontaneous episodes of NSVT. Twenty-four subjects were identified retrospectively as having had one episode of NSVT during 24-hour Holter ECG recording. Methods: We measured the mean interval between normal beats (meanRR), the standard deviation of the intervals between beats (SD), the percentage of counts of sequential intervals between normal beats with a change of >50 ms (%RR50), the logarithms of low- and high-frequency spectral components (InLF, InHF) of HRV for sequential 10-minute segments preceding NSVT. The correlation dimension (CDim) of HRV was calculated similarly for sequential 20-minute segments. We assessed the significance of the time-course change of each marker over the 120-minute period prior to NSVT onset. Results: MeanRR (P < 0.05), InLF (P < 0.0001), InHF (P < 0.0001), the natural logarithm of the ratio of LF to HF (ln[LF/HF]; P < 0.05), and CDim (P < 0.05) showed significant time-course changes during that period, while SD and %RR50 did not. MeanRR, InLF, InHF, and CDim all decreased prior to the onset of NSVT, whereas ln(LF/HF) increased. We divided the subjects into two groups: one consisting of 12 patients with coronary artery disease; and the second group of 12 patients without known coronary artery disease. Both groups showed significant changes (P < 0.05) of CDim, InLF, and InHF preceding the episodes of NSVT. Conclusions: Changes in the pattern of HRV prior to the onset of episodes of NSVT suggest that changes in autonomic activity may commonly play a role in the triggering of spontaneous episodes of NSVT in susceptible patients. The measured changes suggest a reduction in parasympathetic activity, perhaps in conjunction with an increase in sympathetic activity, may trigger NSVT.     

Heart Rate Variability Fraction—A New Reportable Measure of 24‐Hour R‐R Interval Variation

Background: The scatterplot of R‐R intervals has several unique features. Its numerical evaluation may produce a new useful index of global heart rate variability (HRV) from Holter recordings. Methods: Two‐hundred and ten middle‐aged healthy subjects were enrolled in this study. The study was repeated the next day in 165 subjects. Each subject had a 24‐hour ECG recording taken. Preprocessed data were transferred into a personal computer and the standard HRV time‐domain indices: standard deviation of total normal R‐R intervals (SDNN), standard deviation of averaged means of normal R‐R intervals over 5‐minute periods (SDANN), triangular index (TI), and pNN50 were determined. The scatterplot area (0.2–1.8 second) was divided into 256 boxes, each of 0.1‐second interval, and the number of paired R‐R intervals was counted. The heart rate variability fraction (HRVF) was calculated as the two highest counts divided by the number of total beats differing from the consecutive beat by <50 ms. The HRVF was obtained by subtracting this fraction from 1, and converting the result to a percentage. Results: The normal value of the HRVF was 52.7 ± 8.6%. The 2–98% range calculated from the normal probability plot was 35.1–70.3%. The HRVF varied significantly with gender (female 48.7 ± 8.4% vs male 53.6 ± 8.6%, P = 0.002). The HRVF correlated with RRI (r = 0.525) and showed a similar or better relationship with SDNN (0.851), SDANN (0.653), and TI (0.845) than did the standard HRV measures with each other. Bland‐Altman plot showed a good day‐by‐day reproducibility of the HRVF, with the intraclass correlation coefficient of 0.839 and a low relative standard error difference (1.8%). Conclusion: We introduced a new index of HRV, which is easy for computation, robust, reproducible, easy to understand, and may overcome the limitations that belong to the standard HRV measures. This index, named HRV fraction, by combining magnitude, distribution, and heart‐rate influences, might become a clinically useful index of global HRV.     

T‐Wave Alternans and Heart Rate Variability: A Comparison in Patients with Myocardial Infarction with or without Diabetes Mellitus

Background : The aim of this study was to investigate the differences in T‐wave alternans (TWA) and heart rate variability (HRV) among patients with myocardial infarction with or without diabetes mellitus and the relationship between TWA and HRV. Methods: The study population included 133 patients: 59 patients with myocardial infarction (MI) (group post‐MI without diabetes); 40 myocardial infarction with diabetes (group post‐MI with diabetes); and 34 controls (group control). Cardiac autonomic neuropathy assessment was made using frequency domain (low‐frequency [LF] power, high‐frequency [HF] power, LF/HF) and time domain (SDNN, standard deviation of the averaged normal sinus RR intervals for all 5‐minute segments [SDANN]) of HRV indexes. Both TWA and HRV were measured on the Holter monitor, and TWA was calculated automatically using the time‐domain modified moving average method. Results: TWA values differed significantly between controls (40 ± 16 μV) and group post‐MI with (62 ± 17 μV, P < 0.05) or without (60 ± 15 μV, P < 0.05) diabetes. In addition, group post‐MI with diabetes had lower standard deviation of all normal sinus RR intervals (SDNN), standard deviation of the averaged normal sinus RR intervals for all 5‐minute segments (SDANN), and HF, indicating depressed vagus nerve activity, and higher LF/HF ratio, indicating elevated sympathetic nerve activity, than controls and group post‐MI without diabetes (P < 0.05). TWA correlated with SDNN and SDANN (r = 0.29, 0.31; P < 0.001). Conclusions: TWA was elevated in patients following myocardial infarction, both in those with or without diabetes. Myocardial infarction patients had a lower time domain, HF, and a higher LF/HF ratio HRV, especially in those with diabetes. The analysis of modified moving agerage (MMA)‐based TWA and HRV can be a useful tool for identifying post–myocardial infarction patients at high risk of arrhythmic events. Ann Noninvasive Electrocardiol 2011;16(3):232–238     

房间隔缺损经导管封堵术对心率变异性的影响及意义

目的探讨房间隔缺损(ASD)经导管封堵术对心率变异性(HRV)的影响及意义。方法选择成功接受介入治疗的ASD患者118例为研究对象(ASD组),分别于术前1天及术后第4天记录24h动态心电图,由电脑自动分析并经心电专业人员校正,得出HRV的各项时域指标;另按术前心脏超声测得的肺循环血流量/体循环血流量(Qp/Qs)分为Ⅰ组(Qp/Qs<1.5)与Ⅱ组(Qp/Qs≥1.5),分析两亚组患者HRV,并行Qp/Qs与HRV的相关性分析。结果与对照组比较,ASD组封堵术前后24hRR间期标准差(SDNN)及24h内每5min节段RR间期均值标准差(SDANN)均显著降低(P<0.01或0.05);Ⅱ组降低更明显。ASD组封堵术后RR间期、SDNN及SDANN均较术前增加(P<0.05);Ⅱ组介入治疗术后的SDNN、ASDNN较Ⅰ组术后明显减小(P<0.05)。ASD患者术前SDNN及SDANN与Qp/Qs呈负相关(r值分别为-0.528、-0.644,P<0.01)。结论ASD封堵术后HRV水平明显恢复;Qp/Qs越大的ASD患者不仅术前HRV水平降低更显著,术后的恢复也越慢。     

参松养心胶囊对原发性高血压患者心率变异性的影响

目的 探讨参松养心胶囊对原发性高血压患者心率变异性的影响.方法 将68例原发性高血压患者随机分为2组.对照组32例,应用常规降压药物治疗;治疗组(参松养心胶囊组)36例,在高血压治疗的基础上加用参松养心胶囊0.12 g,每天3次,疗程为4周.于治疗前和治疗后4周行24 h动态心电图检查测定其心率变异性时域分析指标.结果 治疗组时域分析指标24 h内正常窦性R-R间期值的标准差(126.4±26.1 ms比110.8±17.9 ms)、24 h内连续每5 min正常R-R间期平均值的标准差(108.4±28.8 ms比98.2±16.2 ms)、24 h内相邻R-R间期差的平方根(28.7±15.2 ms比26.4±15.1 ms)、24 h内相邻正常R-R间期差值大于50 ms的计数占总R-R间期的百分比(8.2%±7.1%比5.9%±5.3%)均较对照组明显提高(P<0.05).结论 参松养心胶囊能显著改善原发性高血压患者心率变异性,改善其预后.