严重充血性心力衰竭患者自主神经功能与心率变异的…

对２５例重度充血性心力衰竭（ＣＨＦ）患者在地高辛治疗前后测定血浆去甲肾上腺素（ＮＥ）及心率变异（ＨＲＶ）。结果显示：ＮＥ基础值与ＨＲＶ时域指标基础水平均呈负相关（Ｐ〈０．０５或〈０．０１）。地高辛治疗前后的ＮＥ相比（２９１±８０ｐｇ／ｍｌｖｓ２１３±８２ｐｇ／ｍｌ），Ｐ〈０．００１。２４小时平均ＲＲ间期及２４小时正常Ｒ间期标准差由治疗前的７２７±１２３ｍｓ及６７．７±２１．８ｍｓ分别增加于７７７《     

经皮冠状动脉腔内成形术对不稳定型心绞痛患者心率变异的影响

应用长程心电图分析系统对１６例不稳定型心绞痛患者（ＵＡＰ组）入院后第２日、经皮冠状动脉腔内成形术（ＲＴＣＡ）后第１，３，３０日以及１４８例健康中、老年人（对照组）２４ｈ心电图进行心率变异（ＨＲＶ）分析。结果：ＵＡＰ组２４ｈ连续正常ＲＲ间期的标准差（ＳＤＮＮ）、２４ｈ内连续５ｍｉｎ节段平均正常ＲＲ间期的标准差（ＳＤＡＮＮｉ）、相邻ＲＲ间期差的均方根（ｒＭＳＳＤ），相邻两个正常心动周期差值大于５０ｍｓ个数占总搏数的百分比（ＰＮＮ５０）、低频功率（ＬＦ）及高频功率（ＨＦ）均明显低于对照组（分别为９２．７±１４．３ｍｓｖｓ１２８．９±１７．８ｍｓ、７８．８±１０．６ｍｓｖｓ１１８．６±１９．１ｍｓ、１９．３±７．７ｍｓｖｓ２９．８±１２．７ｍｓ、３．６±１．７％ｖｓ６．５±５．５％、３１７．２±１４８．３ｍｓ２ｖｓ４７６．５±２８７．３ｍｓ２，Ｐ均＜０．０５），而ＬＦ／ＨＦ高于对照组（３．５±１．３ｖｓ２．４±１．１，Ｐ＜０．０５）。ＰＴＣＡ术后３０天ＵＡＰ患者ＨＲＶ逐渐恢复正常。结果提示ＵＡＰ患者交感神经和迷走神经张力下降，而以后者更明显；ＰＴＣＡ后ＨＲＶ逐渐恢复，说明ＰＴＣＡ能改善ＵＡＰ患者的ＨＲＶ。     

经皮球囊二尖瓣成形术对心率变异的影响

为了解经皮球囊二尖瓣成形术（ＰＢＭＶ）对风湿性心脏病二尖瓣狭窄病人心率变异（ＨＲＶ）的影响，自同期行ＰＢＭＶ的７１例病人中选择窦性心律者作为观察对象。于术前二日和术后第三日记录５ｍｉｎ的心搏数，经短时ＨＲＶ软件分析。结果表明术后ＲＲ间期均值标准差（３３．１８±１０．４２ｍｓｖｓ４２．８０±１５．８４ｍｓ，Ｐ＜０．０５）、相邻ＲＲ间期差值的均方根（２９．６１±１３．３８ｍｓｖｓ３７．５２±２６．０８ｍｓ，Ｐ＜０．０５）、相邻ＲＲ间期差值大于５０ｍｓ的百分比（６．７６±７．４９％ｖｓ９．０３±１０．２３％，Ｐ＜０．０１）、高频能谱（６１５．５８±４８５．６２ｂｐｍ２ｖｓ７０１．９７±６４９．９６ｂｐｍ２，Ｐ＜０．０５）均明显增大或升高。而平均心率（７４．３２±１１．３７ｂｐｍｖｓ６５．８８±７．７３ｂｐｍ，Ｐ＜０．０１）、最大心率（９５．６８±２８．６８ｂｐｍｖｓ７６．１４±８．５３ｂｐｍ，Ｐ＜０．０１）、低频能谱（４３８．２２±４０９．３１ｂｐｍ２ｖｓ２４０．１８±１９８．６８ｂｐｍ２，Ｐ＜０．０１）、极低频能谱（９７１．７４±５２９．５３ｂｐｍ２ｖｓ７２１．４３±５６４．０９ｂｐｍ２，Ｐ＜０．０１）均明显降?     

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?     

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。     

β-受体阻断剂和血管紧张素转换酶抑制剂对心肌梗死患者心率变异影响的比较

为了解β－受体阻断剂和血管紧张素转换酶抑制剂（ＡＣＥＩ）对心肌梗死患者心率变异（ＨＲＶ）的影响，采用惠普系列双通道动态心电图机对５３例急性心肌梗死（ＡＭＩ）和３２例陈旧性心肌梗死（ＯＭＩ）患者进行了ＨＲＶ分析。β－受体阻断剂治疗的ＡＭＩ患者（Ｂ组）与对照组（常规治疗的ＡＭＩ患者即Ｃ组）相比，２４ｈＲＲ间期总体标准差（ＳＤＮＮ）、相邻ＲＲ间期大于５０ｍｓ的百分比（ｐＮＮ５０）均增加（７．２６±３．４４ｍｓｖｓ４．２７±２．０１ｍｓ，１２６．３４±３０．０５ｖｓ９１．４８±２９．２１，Ｐ均＜０．０５），高频带（ＨＦ）增大（８．５３±１．９７ｍｓ２／Ｈｚｖｓ６．７２±２．０８ｍｓ２／Ｈｚ，Ｐ＜０．０５），低频带（ＬＦ）降低（１２．６４±３．０５ｍｓ２／Ｈｚｖｓ１５．３１±４．２１ｍｓ２／Ｈｚ，Ｐ＜０．０１）。ＡＣＥＩ治疗的ＡＭＩ患者（Ａ组）与对照组（ｃ组）相比，ｐＮＮ５０增加（１２３．５９±２７．６３ｖｓ９１．４８±２９．２１，Ｐ＜０．０５），低频与高频的比值降低（２．１３±１．０５ｖｓ２．３５±０．８７，Ｐ＜０．０５），其中伴有心力衰竭者与不伴心力衰竭者相比ＨＲＶ改善较显著。ＡＣＥＩ和β－受体阻断剂对ＯＭＩ患者?     

非持续性室性心动过速患者心率变异的研究

对非持续性室性心动过速（ＮＳＶＴ）患者进行心率变异（ＨＲＶ）分析。记录２４ｈ动态心电图分析６个ＨＲＶ时域指标，并对照分析ＮＳＶＴ发作前、后的窦性Ｒ－Ｒ间期标准差（ＳＤ）。结果：ＮＳＶＴ患者（ｎ＝３５）之ＨＲＶ时域指标中２４ｈ平均Ｒ－Ｒ间期（ＭＲＲＩ）、ＳＤ、５ｍｉｎ节段Ｒ－Ｒ间期均值的标准差（ＳＤＡ）、５ｍｉｎ节段Ｒ－Ｒ间期标准差的均值（ＭＳＤ）较正常对照组（ｎ＝１０５）明显下降（其中ＳＤ为９０．８８±３７．７７ｍｓｖｓ１４３．１８±３１．００ｍｓ，Ｐ＜０．０１），与病例对照组（ｎ＝４４）比较无显著性差异（Ｐ＞０．０５）。ＮＳＶＴ发作前、后５ｍｉｎ和１ｈ的ＳＤ（５ｍｉｎＲ－Ｒ节段）无显著性差异。结论：ＮＳＶＴ患者ＨＲＶ较正常对照组下降，但ＨＲＶ下降与ＮＳＶＴ无明显关系。     

不同龄SHR心肌细胞内Ca~（2＋）及心肌组织NE含量的变化

采用荧光探针结合计算机图像处理技术测定幼年、成年、老年ＳＨＲ心肌单细胞内游离Ｃａ~（２＋）浓度，采用高压液相色谱法测定幼年、成年、老年ＳＨＫ心肌去甲肾上腺素（ＮＥ）含量。结果显示随着年龄增加，ＳＨＲ心肌细胞内游离Ｃａ~（２＋）增加，而心肌组织ＮＥ含量下降。与老年ＷＫＹ大鼠比较，老年ＳＨＲ心肌细胞内Ｃａ（２＋）含量较高（Ｐ＜０．０１），而其心肌组织ＮＥ含量却较少（Ｐ＜０．０５）。本研究提示心肌组织ＮＥ与ＳＨＲ的血压升高及心肌细胞内游离Ｃａ~（２＋）增多无直接关系。＊Ｐ＜０．０１，ａ．ｖｓ．ＳＨＲ２ｍ，ｂ．ｖｓＳＨＲ６ｍ，ｃ．ｖｓ．ＳＨＲ１２ｍ３不同年龄阶段ＳＨＲ心肌组织ＮＥ含量ＳＨＲ的年龄越大，其心肌组织ＮＥ的含量越少，各年龄组之间均有显著差异（Ｐ＜０．０１）。与老年ＷＫＹ大鼠比较．老年ＳＨＲ是心肌组织ＮＥ含量明显降低（Ｐ＜０．０５）（Ｆｉｇ３）。Ｆｉｇ３ＮＥｃｏｎｔｅｎｔｓｉｎｃａｒｄｉａｃｔｉｓｓｕｅｓＩｎＳＨＲｓｏｆｖａｒｉｏｕｓａｇｅｓａｎｄｅｌｄｅｒＷＫＹｒａｔｓ：Ｐ＜０．０５．＊：Ｐ＜０．０１，ａ．ｖｓ．ＳＨＲ２ｍ，ｂ．ｖｓＳＨＲ６ｍ．ｃ．ｖｓＳＨＲ１２ｍ．ＤＩＳＣＵＳＳＩＯＮＦｕｒａ－２能选择性地     

急性心肌梗塞患者心率变异性及其临床意义

采用心率变异性（ＨＲＶ）时域指标──２４ｈ心电图中全部窦性Ｒ－Ｒ间期标准差（ＳＤＮＮ），研究急性心肌梗塞（ＡＭＩ）患者ＨＲＶ改变及其与肌酸激酶同功酶（ＣＫ－ＭＢ）、心功能和住院期间病死率的关系。结果显示：ＡＭＩ后２～３ｄ的ＳＤＮＮ（６０．５３±２０．６０ｍｓ）较正常对照组（１３０．２０±３０．４１ｍｓ）显著降低（Ｐ＜０．００１），并与ＣＫ－ＭＢ峰值呈显著负相关（ｒ＝－０．４８，Ｐ＜０．０５）；服用美多心安者的ＳＤＮＮ显著高于未服者（６１．２７±１３．４４ｍｓＶＳ４７．５３±１１．２５ｍｓ，Ｐ＜０．０５）；心功能Ⅱ～Ⅳ级者ＳＤＮＮ显著低于Ⅰ级者（４９．７１±１８．１０ｍｓＶＳ６８．５２±１８．８０ｍｓ，Ｐ＜０．０１）；住院期间死亡者ＳＤＮＮ显著低于存活者（４２．２５±６．４５ｍｓＶＳ６２．５６＋２０．６３ｍｓ，Ｐ＜０．０１）；ＳＤＮＮ＜５０ｍｓ者的住院病死率显著高于＞５０ｍｓ者（３１％ＶＳ０，Ｐ＜０．０５）。提示ＡＭＩ早期心脏交感神经活动增强而迷走神经活动受抑制，其改变的程度与心功能损害和梗塞面积相关；ＡＭＩ早期测定ＨＲＶ可获得重要临床信息和有助于对患者作早期危险性的分层。     

实验性心肌缺血大鼠心脏自主神经活性的动态变化及意义

采用心率变异（ＨＲＶ）时域及频域指标分析急性心肌缺血２４ｈ大鼠心脏自主神经功能的变化以探讨其意义。将实验动物分成三组，即正常对照组（２０只）、假手术组（２０只）与心肌缺血组（４８只），并运用动态心电图记录２４ｈ心电信号变化。结果显示：与假手术组及正常对照组分别比较，心肌缺血组正常窦性心律ＲＲ间期标准差（ＳＤＮＮ）下降（２８．９±９．４ｍｓｖｓ３４．４±１３．７ｍｓ或３５．１±１４．３ｍｓ，Ｐ均＜０．０５），低频（ＬＦ）及低频与高频的比值（ＬＦ／ＨＦ）明显增加（１８９．４±３６．５ｍｓ２／Ｈｚｖｓ５７．３±１７．８ｍｓ２／Ｈｚ或５１．８±１８．６ｍｓ２／Ｈｚ；３．８５±０．９１ｖｓ１．７６±０．６３或１．６８±０．５７，Ｐ均＜０．０１）；２４ｈ心率功率谱示心肌缺血组ＬＦ及ＬＦ／ＨＦ波动幅度较假手术组及正常对照组增高，缺血大鼠ＬＦ与ＬＦ／ＨＦ在缺血后０～３ｈ（２６７．５±１２．４ｍｓ２／Ｈｚ、４．３３±１．０８）及９～１２ｈ（２４４．７±１３．９ｍｓ２／Ｈｚ、３．９６±０．９８）期间增高显著，而在缺血后５～７ｈ（１４９．２±８．７ｍｓ２／Ｈｚ、２．０５±０．４２）内则相对较低。结果表明大鼠心肌缺血后ＨＲＶ降低主?     

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。     

心率变异对甲状腺机能亢进患者自主神经功能的评价

采用短时采样的时域、频域法对１８例初诊甲状腺机能亢进（简称甲亢）患者（甲亢组）进行心率变异分析，并以１８例正常人作为对照（对照组），了解甲亢患者自主神经功能的改变。与对照组相比，甲亢组平均ＲＲ间期、ＲＲ平均值标准差、相邻ＲＲ间期差值的均方根、相邻ＲＲ间期相差＞５０ｍｓ占总心动周期数的百分比均明显降低（分别为５５４．５３±６７．７９ｍｓｖｓ８５８．３６±９０．４３ｍｓ、１６．４１±５．５０ｍｓｖｓ４３．０８±１１．０４ｍｓ、１１．３２±３．１６ｍｓｖｓ３７．４３±１０．１２ｍｓ、０．３３±０．５１％ｖｓ１５．２２±１２．８４％，Ｐ均＜０．００１）。极低频段成分明显升高、高频段（ＨＦ）成分明显降低（分别为３８．３２±８．６０ｍｓ２／Ｈｚｖｓ２５．１１±１０．７８ｍｓ２／Ｈｚ、１２．７７±７．０４ｍｓ２／Ｈｚｖｓ３５．６５±１５．０８ｍｓ２／Ｈｚ，Ｐ均＜０．００１）、低频段（ＬＦ）成分无明显改变（２７．１２±１１．３４ｍｓ２／Ｈｚｖｓ２９．６０±１０．３１ｍｓ２／Ｈｚ，Ｐ＞０．０５），ＬＦ／ＨＦ明显增高（２．７６±１．７１ｖｓ１．１７±１．０８，Ｐ＜０．００２），心率总功率谱密度无明显变化。提示甲亢患者不仅交感神?     

左房线性消融治疗阵发性心房颤动对心率变异性的影响

目的通过观察左房线性消融术治疗阵发性心房颤动(简称房颤)术后心率变异性(HRV)的变化来评价其对自主神经系统的影响。方法对25例行射频消融术的阵发性房颤患者,术前及术后第3天行24h动态心电图检查,分别测定最大心率,最小心率,平均心率;时域指标:RR间期标准差(SDNN),RR间期平均值的标准差(SDANN),相邻RR间期差的均方根(RMMSD),相邻RR间期差值超过50ms的RR间期所占百分数(PNN50);频域指标:低频功率(LF),高频功率(HF),低频高频比值(LF/HF)。结果患者术前最大心率,最小心率,平均心率,SDNN,SDANN,RMSSD,PNN50,LF,HF,LF/HF分别为151±41次/分,47±5次/分,70±9次/分,126±26ms,111±24ms,27±7ms,6±5ms,98±66ms2,86±119ms2,2.4±3.5;术后各指标分别为136±37次/分,66±8次/分,84±9次/分,57±17ms,53±17ms,16±7ms,2±3ms,18±19ms2,16±19ms2,1.2±1.6;手术前后各指标相比,差异有显著性(P均<0.05)。结论左房线性消融术后HRV降低,此可能是射频消融治疗房颤的机制之一。     

急性重度脑外伤患者自主神经功能变化的研究

为探讨急性重度脑外伤（ASTBI）患者是否存在自主神经（ANS）功能障碍及其临床意义,对30例ASIBI患者（ASTBI组,GCS评分≤8分）于入院1周内进行24小时心率变异性（HRV）检测,动态心电图分析系统自动计算HRV各项指标（包括时域、频域和非线性分析）,绘制HRV直方图、散点图,并与31例正常人（对照组）进行比较。结果 ASTBI组HRV多数指标均明显降低（P＜0．05－0．001）;HRV直方图、散点图;均有特 征性改变,存活者和死亡者的HRV时域分析、频域分析各项指标比较有统计学意义。认为HRV能定量、全面、直观地反映ASTBI患者交感神经和迷走神经的功能状态;ASTBI患者存在明显的ANS功能障碍;ANS功能障碍与病情严重性呈正相关,且常直接影响预后。     

慢性充血性心力衰竭患者心率变异性及其昼夜节律变化

目的分析慢性充血性心力衰竭(CHF)患者心率变异性(HRV)及其昼夜节律的变化,了解CHF患者自主神经功能损害与心功能的关系。方法用24小时动态心电图分析38例CHF患者,20例心功能代偿的心血管病患者心功能代偿组,16例健康体检者对照组的HRV时域指标。比较三组间HRV指标的差异;计算CHF患者HRV昼夜指标差异,分析CHF患者24小时HRV指标变化与心功能NYHA分级的关系。结果心功能代偿组24小时HRV时域指标SDNN、SDANN和SDNNindex较对照组显著下降P<0.01、0.05和0.05rMSSD和pNN50与对照组无显著差别P>0.05;CHF组的HRV各指标均显著低于对照组均P<0.01且昼夜指标变化无差异;将CHF组分为心功能Ⅱ级组n=20和心功能≥Ⅲ级n=18两个亚组结果发现心功能≥Ⅲ级的HRV各指标明显低于心功能Ⅱ级组P<0.01。结论心血管病患者可能在心功能代偿期时自主神经的平衡就已受到损害当出现CHF时交感活性增强迷走神经张力进一步下降,自主神经调节昼夜节律性丧失,且HRV指标的下降与心功能损害程度相关因此HRV时域指标可作为评价CHF预后指标之一。     

Cigarette Smoking and Heart Rate Variability: Dynamic Influence of Parasympathetic and Sympathetic Maneuvers

Background: Cigarette smoking has been associated with increased activity of the sympathetic nervous system. In this study, we investigated cardiac autonomic function in heavy smokers and nonsmoker controls by analysis of heart rate variability (HRV). Method: Twenty‐four long‐term heavy smokers (men) and twenty‐two nonsmoker subjects (hospital staff) were included to study. Time domain [mean R‐R interval (RR), the standard deviation of R‐R interval index (SDNN), and the root mean square of successive R‐R interval differences (RMSSD)] and frequency domain [high frequency (HF) low frequency (LF), and LF/HF ratio] parameters of HRV were obtained from all participants after 15 minutes resting period in supine position (S), during controlled respiration (CR), and handgrip exercise (HGE) over 5‐minute periods. Results: Baseline SDNN and RMSSD values were found to be lower in smokers than in nonsmokers. (64 ± 10 vs 78 ± 22, P < 0.05 and 35 ± 12 vs 54 ± 30 ms, P < 0.05). Baseline LF/HF ratio was also found to be higher in smokers than in nonsmokers (1.3 ± 0.6 vs 0.9 ± 0.5 ms, P < 0.05). The other HRV parameters including R‐R interval, LF, and HF were not significantly different. During CR, expected increase in RR, SDNN, and RMSSD did not occur in smokers, while it did occur in nonsmokers. Most HRV indices were significantly affected by HGE in both groups. In addition, the duration of smoking was found to be inversely correlated with RMSSD and HF and positively correlated with LF/HF ratio. Conclusion: Vagal modulation of the heart is blunted in heavy smokers, particularly during a parasympathetic maneuver. Blunted autonomic control of the heart may partly be associated with adverse event attributed to cigarette smoking.     

Moderate intensity exercise improves heart rate variability in obese adults with type 2 diabetes

AimThe aim of this study was to determine the effect of moderate aerobic exercise on heart rate variability (HRV) in obese adults with type 2 diabetes.MethodsForty-one obese adults with type 2 diabetes participated in this study. Anthropometric and metabolic parameters were measured, and resting electrocardiogram (ECG) for the HRV analysis at spontaneous respiration was recorded for 5 min in supine position before and after six months of supervised aerobic training given thrice-a-week.ResultsThe mean age, body mass index (BMI), and duration of diabetes of the study population were 44.1 ± 4.5 years, 30.94 ± 1.36 kg/m2, and 16.3 ± 2.7 years, respectively. In time domain variables, standard deviation of all RR intervals (SDNN), the square root of the mean of the sum of the squares of differences between adjacent RR intervals (RMSSD) and percentage of consecutive RR intervals that differ by more than 50 ms (pNN50) were significantly increased after exercise. In frequency domain variables, high frequency (HF) (ms2) and HF (nu) were significantly increased while low frequency (LF) (ms2) and LF/HF ratio were significantly decreased after exercise. But LF (nu) was unaffected after exercise.ConclusionThis study suggests that thrice-a-week moderate intensity aerobic exercise for six months improves cardiac rhythm regulation as measured by HRV in obese adults with type 2 diabetes     

Effect of Beta‐Blockade on Autonomic Modulation of Heart Rate and Neurohormonal Profile in Decompensated Heart Failure

Background: One of the putative mechanisms for the salutary effects of beta‐blockers in patients with congestive heart failure (CHF) is their ability to improve autonomic dysfunction. However, patients with profound neurohumoral abnormalities derive little survival benefit from beta‐blockers. The purpose of the current study was to evaluate the effect of beta‐blockers on heart rate variability (HRV) in decompensated CHF. Methods: Time and frequency domain HRV indices were obtained from 24‐hour Holter recordings and compared to assess the role of beta‐blockade in 199 patients (mean age 60 ± 14 years) with decompensated CHF. Neurohormonal differences were assessed by measuring norepinephrine, endothelin‐1, tumor necrosis factor‐a, and interleukin‐6 in a subset of 64 patients. Results: All HRV indices were markedly suppressed but were substantially higher in patients who were on beta‐blockers. Time domain measures of parasympathetic cardiac activity, the percentage of R‐R intervals with > 50 ms variation (4.9 ± 0.6 vs 7.7 ± 1.2%, P = 0.006) and the square root of mean squared differences of successive R‐R intervals (22.7 ± 2.0 vs 31.6 ± 4.1 ms, P = 0.004), were higher in the beta‐blocker group. Spectral analysis revealed that the total power and the ultra‐low frequency power were significantly higher in patients on beta‐blockers (82% and 59%, respectively). The high frequency power, a spectral index of parasympathetic modulation, was 41% higher in the beta‐blocker group (121 ± 25 vs 171 ± 27 ms2, P = 0.02). Norepinephrine and interleukin‐6 levels were substantially lower in patients on beta‐blockers (28% and 61%, respectively). However, these differences did not reach statistical significance. Conclusions: Beta‐blockers improve the impaired cardiac autonomic regulation during high sympathetic stress of decompensated CHF. This effect may play an important role in protecting the myocardium and preventing arrhythmias during transient increases in sympathetic activity. A.N.E. 2001;6(2):98–106     

正常人群的心率变异性分析

将１００４例正常人分三个年龄组进行短程（５ｍｉｎ）心率变异性（ＨＲＶ）分析。时域法的参数为平均心率标准差（ＨＲＳＤ），连续５ｍｉｎ节段平均正常ＲＲ间期标准差（ＳＤＡＮＮ），相邻ＲＲ间期差的均方根（ｒＭＳＳＤ），相邻ＲＲ间期差异≥５０ｍｓ的百分数（ＰＮＮ_（５０））；频域法的参数为极低频（ＶＬＦ）、低频（ＬＦ）、高频（ＨＦ）成分，总功率（ＴＰ）及ＬＦ／ＨＦ比值。各指标间做相关分析。结果：４５岁以上组ＨＲＳＤ、ＳＤＡＮＮ、ｒＭＳＳＤ、ＰＮＮ_（５０）、ＶＬＦ、ＬＦ、ＨＦ、ＴＰ均低于４５岁以下两组（Ｐ＜０．０５或＜０．０１）。ＳＤＡＮＮ、ｒＭＳＳＤ、ＰＮＮ_（５０）与ＨＦ呈高度正相关（ｒ＞０．７０，Ｐ＜０．０００１），其中以ＳＤＡＮＮ、ＰＮＮ_（５０）相关更好（ｒ＞０．７５，Ｐ＜０．００１），ＳＤＡＮＮ、ｒＭＳＳＤ、ＰＮＮ_（５０）间高度相关（ｒ＞０．８０，Ｐ＜０．０００１）。不同性别ＨＲＶ各参数相比无显著差异。提示：ＨＲＶ随年龄的增长而下降，以迷走神经张力下降为主；各指标中以ＳＤＡＮＮ、ｒＭＳＳＤ、ＰＮＮ_（５０）、ＨＦ能更好地反映迷走神经张力变化。