急性心肌梗塞患者尿儿茶酚胺变化及其与临床和心率变异性…

使用高效液相色谱分离技术连续测定２５例急性心肌梗塞（ＡＭＩ）中层得发病初４周２４小时尿儿茶胺含量及变化，ＡＭＩ患者尿去甲肾上腺素（ＮＥ）和多巴胺含量明显升高，随病情恢复逐步下降，以发病后第一周下降幅度最大，ＮＥ含量与心率变异三项参数极低频成分，总成分和连续５分钟正常民率间期标准差均值相关（ｒ＝－０．７１２３，－０．６１５，－０．５２８，Ｐ〈０．０５）；与心肌酶相关（ｒ＝０．６３５，Ｐ〈０．０５），     

心功能障碍患者心肌组织及血浆肾素－血管紧张素系统、心钠素改变的临床意义

１９例心功能障碍患者的血浆、心肌血管紧张素Ⅱ（ＡｎｇⅡ）、心钠素（ＡＮＦ）含量高于正常对照组；血浆ＡｎｇⅡ和ＡＮＦ含量增高与心脏指数（ＣＩ）呈显著负相关（ｒ＝－０．５９６８，Ｐ＜０．０５；ｒ＝－０．８９９６，Ｐ＜０．０１），心肌ＡｎｇⅡ含量变化与左室心肌重量（ＬＶＭ）呈显著正相关（ｒ＝０．５７２３，Ｐ＜０．０５）；提示心脏局部肾素－血管紧张素系统（ＲＡＳ）活性增高和ＡＮＦ变化参与心肌细胞增殖及心室重塑的意义较为突出。     

白细胞介素－4和γ－干扰素与哮喘发病关系的探讨

为进一步探讨白细胞介素－４（ＩＬ－４）和干扰素（ＩＦＮ－ｒ）与哮喘发病的关系，对发作期哮喘病人及正常人各２０例，检测其外周血淋巴细胞（ＰＢＬＣｓ）培养上清中ＩＬ－４含量、ＩＦＮ－ｒ活性及血清ＩｇＥ总浓度。结果表明：发作期哮喘组ＩＬ－４和ＩｇＥ均非常显著地高于正常对照组（Ｐ＜０．００１）：ＩＬ－４与ＩｇＥ之间呈正相关（ｒ＝０．８２），Ｐ＜０．００１；ＩＬ－４与ＩＦＮ－及ＩＦＮ－与ＩｇＥ之间均呈负相关（ｒ＝０．４８，－０．７５），Ｐ＜０．０５，Ｐ＜０．０１。二组之间ＩＦＮ的活性无显著性差异，Ｐ＞０．０５。提示发作期哮喘病人ＩＬ－４的高水平分泌导致的ＩｇＥ过多合成，可能与哮喘的发病有直接的关系。ＩＬ－４与ＩＦＮ之间的失衡对血清ＩｇＥ的合成起了重要的调控作用。     

高血压患者血浆和淋巴细胞中血管紧张素Ⅱ、内皮素和一氧化氮的变化及关系

分析一组高血压病患者血浆和淋巴细胞中血管紧张素Ⅱ（ＡｎｇⅡ）、内皮素（ＥＴ）和一氧化氮（ＮＯ）含量的变化及它们间的相互关系。方法高血压（ＥＨ）组３９例，正常对照（ＮＣ）组４１例，放射免疫分析法测定ＡｎｇⅡ、ＥＴ，高效液相色谱分析法测定ＮＯ。结果ＥＨ患者血浆和淋巴细胞中ＥＴ均高于ＮＣ组（Ｐ分别＜０．０５和＜０．０１），ＮＯ低于ＮＣ组（Ｐ分别＜０．０５和＜０．０１）。除血浆ＥＴ和ＮＯ外，各指标改变ＥＨⅡ期较Ⅰ期明显（Ｐ分别＜０．０５和＜０．０１）。逐步回归分析表明，ＥＨ组平均动脉压（ＭＡＰ）与血浆及淋巴细胞中ＡｎｇⅡ、ＥＴ呈正相关，与ＮＯ负相关（ｒ分别＝０．６７，０．８１，Ｐ均＜０．０１）；ＥＨ组血浆和淋巴细胞中ＮＯ与ＡｎｇⅡ、ＥＴ均呈负相关（ｒ分别＝－０．６５１，－０．７２５，Ｐ均＜０．０１）。结论淋巴细胞反映血管内皮细胞内分泌功能比血浆更为敏感，与ＭＡＰ相关性更好，ＡｎｇⅡ、ＥＴ和ＮＯ三者分泌失平衡，是ＥＨ发病的重要原因之一。     

NIDDM病人红细胞变形能力与红细胞ATP酶活性和红细胞内离子浓度关系的研究

本文检测了４２例ＮＩＤＤＭ病人红细胞变形能力（ＥＤ）和红细胞ＡＴＰ酶活性、红细胞内离子浓度的变化。结果显示ＮＩＤＤＭ病人红细胞滤过指数（ＩＦ）较对照组明显增高（Ｐ＜０．００１）；红细胞Ｎａ＋－Ｋ＋－ＡＴＰ酶和Ｃａ２＋－ＡＴＰ酶活性较对照组明显降低（Ｐ＜０．０１），Ｍｇ２＋－ＡＴＰ酶活性变化不明显；红细胞内Ｎａ＋、Ｃａ２＋浓度较对照组明显增高（Ｐ＜０．０１），而Ｍｇ２＋浓度较对照组明显降低（Ｐ＜０．０１）。有血管病变者这些变化较无血管病变者更明显。ＮＩＤＤＭ病人红细胞ＩＦ与Ｎａ＋－Ｋ＋－ＡＴＰ酶、Ｃａ２＋－ＡＴＰ酶活性呈负相关（ｒ＝－０．４６８，－０．４５８，Ｐ＜０．００１），与红细胞内Ｎａ＋、Ｃａ２＋浓度呈正相关（ｒ＝－０．４７３，０．４６６，Ｐ＜０．Ｄ０１），与Ｍｇ２＋浓度呈负相关（ｒ＝－０．４３６，Ｐ＜０．０１）。     

血清肌钙蛋白T动态监测预测心肌梗塞面积的研究

对２４例急性心肌梗塞（ＡＭＩ）患者心肌梗塞后肌钙蛋白Ｔ（ＴｎＴ）释放量与心肌断层显像测定梗塞相对面积以及左室射血分数（ＬＶＥＦ）的相关性进行研究。结果显示：２４小时内ＴｎＴ峰值与心肌梗塞相对面积无明显相关性（ｒ＝０．３３，Ｐ＞０．０５）；２４小时后ＴｎＴ峰值与心肌梗塞面积呈正相关（ｒ＝０．８１，Ｐ＜０．０１）；累积ＴｎＴ（ΣＴｎＴ）释放量与相对梗塞面积呈显著正相关（ｒ＝０．９０，Ｐ＜０．０１）；２４小时后ＴｎＴ峰值与ＬＶＥＦ呈显著负相关（ｒ＝－０．５４，Ｐ＜０．０１）。表明，ＡＭＩ后ＴｎＴ的后期释放峰值及释放量是判断心肌梗塞面积的良好参数，对预测心肌梗塞后心功能状态亦有参考价值。     

复方丹参注射液对老年肺心病患者血浆丙二醛水平和红细胞变形能力的影响

观察５９例老年肺心病患者血浆丙二醛（ＭＤＡ）水平和红细胞变形能力（ＲＣＤ，用红细胞滤过指数ＲＢＣ－ＩＦ表示）的变化及复方丹参注射液对ＭＤＡ水平和ＲＣＤ的影响。在肺心病急性加重期血浆ＭＤＡ水平明显增高，ＲＣＤ明显降低，全血粘度（高切）明显增高；ＭＤＡ与ＲＢＣ－ＩＦ呈正相关（ｒ＝０．４８，Ｐ＜０．０５），ＲＢＣ－ＩＦ与全血粘度（高切）呈正相关（ｒ＝０．５４，Ｐ＜０．０５）。用复方丹参治疗后的患者ＭＤＡ水平、ＲＢＣ－ＩＦ及全血粘度（高切）均明显低于未用复方丹参治疗者（Ｐ均＜０．０５），病程也明显短于未用丹参治疗者（Ｐ＜０．０５）。这揭示复方丹参注射液有良好的治疗作用。     

老年及老年前期急性心肌梗死病人血浆β内啡肽、精氨酸加压素的动态改变

观察２５例老年及老年前期急性心肌梗死（ＡＭＩ）病人血浆β内啡肽（β－ＥＰ）、精氨酸加压素（ＡＶＰ）在梗死后第１，２，３，４，５，６，７，１４，２１天的动态变化，并与２０例正常人作对照，结果显示：在ＡＭＩ时血浆β－ＥＰ水平各天均低于正常人（Ｐ＜０．０５），其变化可能与儿茶酚胺抑制垂体释放β－ＥＰ有关；血浆ＡＶＰ在第４、５天水平高于正常人（Ｐ＜０．０５），其升高可能是机体应激反应所致。在ＡＭＩ伴有合并症时血浆β－ＥＰ水平高于无合并症者（Ｐ＜０．０５），其升高可能参与ＡＭＩ时上述合并症的发生。     

非胰岛素依赖性糖尿病尿α_1-微球蛋白、THP与肾小管功能的研究

为探讨ＮＩＤＤＭ肾病各期肾小管各节段功能变化，用放射免疫分析法（ＲＩＡ）测定２０例健康对照者及６２例非胰岛素依赖性糖尿病（ＮＩＤＤＭ）患者尿白蛋白排泄率（ＵＡＥＲ），尿α１－微球蛋白（α１－ＭＧ）排泄率（Ｕα１ＥＲ）及尿Ｔａｍｍ－Ｈｏｒｓｆａｌ蛋白（ＴＨＰ）排泄率（ＵＴＨＥＲ）。结果：①Ｕα１ＥＲ均值各组间比较结果：正常白蛋白尿组（ＤＭ－Ⅲ）较健康对照组（Ｃ组）升高无统计学意义（Ｐ＞０．０５），但ＤＭ－Ｉ组中，有９例（３５％）Ｕα１１ＥＲ显著升高（Ｐ＜０．０５）；微量白蛋白尿组（ＤＭ－Ⅱ）较ＤＭ－Ｉ组显著增高（Ｐ＜０．０５）。②ＵＴＨＥＲ最大均值位于大量白蛋白尿组（ＤＭ－Ⅲ）组，较Ｃ组显著降低（Ｐ＜０．０５）；最小均值位于ＤＭ－Ⅱ组与Ｃ组比较ＵＴＨＥＲ无显著性差异（Ｐ＞０．０５）。提示：①ＮＩＤＤＭ微量白蛋白尿期即可伴肾小管功能损伤且部分患者Ｕα１ＥＲ、ＵＴＨＥＲ增高先于ＵＡＥＲ的改变而反映肾脏受累。②ＮＩＤＤＭ肾小管功能损伤既有近曲小管重吸收功能障碍，亦存在髓袢合成、分泌功能异常。③联合检测ＵＡＥＲ、ＵＴＨＥＲ、Ｕα１ＥＲ有助于临床早期、全面判断ＮＩＤＤＭ肾脏病变部位及程度。     

内皮素在大鼠高血压心肌肥大中的作用

目的研究内皮素（ＥＴ）在一氧化氮合酶（ＮＯＳ）抑制剂亚硝基左旋精氨酸甲酯（Ｌ－ＮＡＭＥ）诱导的高血压心肌肥大中的作用及ＥＴＡ受体阻断剂ＪＫＣ－３０１的保护效应。方法复制大鼠Ｌ－ＮＡＭＥ高血压模型，动物分对照组、高血压组和ＪＫＣ－３０１治疗组，测定心重、血浆及心肌ＥＴ水平和心肌丝裂素活化蛋白激酶（ＭＡＰＫ）活性。结果高血压动物的心重、ＥＴ水平和心肌ＭＡＰＫ活性较对照组都显著升高（Ｐ＜０．０１或０．０５），加用ＪＫＣ－３０１治疗则较高血压组ＥＴ水平不变，但血压、心重和ＭＡＰＫ活性均降低（Ｐ＜０．０１或０．０５），心肌ＭＡＰＫ活性与左心室肥大程度呈正相关（ｒ＝０．８２，Ｐ＜０．０１）。结论一氧化氮缺乏的心肌肥大可能是由ＥＴ所介导的，ＥＴＡ受体阻断剂对此种肥大有防治作用     

急性冠脉综合征患者窦性心率震荡变化特点及其与心率变异性的相关性研究

目的分析急性冠脉综合征（ACS）患者窦性心率震荡（HRT）指标变化特点及其与心率变异性（HRV）的相关性。方法应用相应的分析软件对与59名健康体检者和161例确诊为ACS的患者24h动态心电图检查结果进行分析,检测HRT参数震荡初始（TO）、震荡斜率（TS）和HRV时域指标24h正常RR间期标准差（SDNN）、全程相邻窦性R—R间期之差的均方根值（rMSSD）、相邻正常RR间期差值〉50ms的心搏数占总RR间期数的百分比（PNN50）。将ACS组分为不稳定型心绞痛（UAP）组和急性心肌梗死（AMI）组,比较HRT、HRV指标和HRT异常的发生率在各组间的差异,进一步探讨ACS患者HRT和HRV指标相关性。结果与健康对照组比较,UAP组及AMI组TO明显增高,TS显著降低（均P〈0．01）;UAP组及AMI组间TO和TS无显著差异。UAP组及AMI组HRT异常率较对照组显著升高（X^2=5．385,P〈0．05;r=9．227,P=0．01）。UAP组及AMI组HRV指标SDNN、rMSSD、PNN50较对照组显著降低（均P〈0．01）,AMI组SDNN较UAP组降低（P〈0．05）,rMSSD、PNN50差异无统计学意义。ACS患者的TO与SDNN呈负相关（r=-0．26,P=0．031）,与rMSSD、PNN50不相关,TS与SDNN、PNN50、RMSSD呈正相关,其中和SDNN的相关性最强（r=0．301,P=0．047）。结论HRT可作为ACS危险分层的一项新的心电学筛选指标。ACS患者HRT、HRV变化从不同方面反映心脏迷走神经的功能受损,二者互相联系又相互独立。     

激活蛋白1及基质金属蛋白酶在急性心肌梗死后心脏组织中的表达

目的 观察激活蛋白-1(AP-1)、基质金属蛋白酶类(MMPs)在急性心肌梗死(AMI)患者心脏组织中的表达及意义.方法 采用免疫组化技术分别榆测AP-1亚单位c-Jun、MMP-2及MMP-9在人正常及AMI心脏组织中的表达.结果 (1)正常心脏组织可少量表达c-Jun、MMP-2及MMP-9;在AMI心脏组织中c-Jun、MMP-2及MMP-9表达较正常心脏组织明显增加(P值均<0.05).(2)在AMI心脏组织中,MMP-9表达水平与c-Jun表达水平明显呈正相关(r=0.773,P<0.01).结论 在AMI心脏组织中AP-1及MMPs表达均明显升高,提示AP-1转录激活及MMPs表达增加可能在AMI后心室重构中发挥重要的作用.     

Heterogeneous myocardial catecholamine concentrations in patients with congestive heart failure

Left ventricular catecholamine and plasma norepinephrine levels were assayed in 39 patients undergoing cardiac transplantation to test the hypothesis that in congestive heart failure (CHF) the normally high concentration of myocardial norepinephrine is depleted while dopamine is increased because dopamine conversion to norepinephrine is the rate-limiting step in norepinephrine synthesis. Plasma norepinephrine was elevated in all patients (average 741 +/- 472 micrograms/ml), but myocardial norepinephrine was variable, ranging from 79 to 2,127 ng/g (average 512 +/- 392). Myocardial dopamine also varied considerably (range 0 to 713 ng/g, average 143 +/- 150). Nineteen patients had the expected pattern of low cardiac norepinephrine and elevated dopamine levels. However, myocardial catecholamine levels were normal (high norepinephrine, low dopamine) in 7 patients; both norepinephrine and dopamine were low in 6 patients; and norepinephrine levels were preserved but dopamine high in 7 patients. Cardiac norepinephrine level correlated only weakly with peripheral vascular resistance (r = 0.39, p less than 0.05), and examination of multiple other variables failed to reveal likely causes of the differences in cardiac norepinephrine and dopamine between patients. Thus, myocardial norepinephrine is not uniformly reduced in patients with severe CHF, and further attempts to delineate the factors regulating myocardial catecholamine concentration and adrenergic function in such patients are needed.     

急性心肌梗死患者血B型利钠肽水平与心功能的相关性和诊断心力衰竭的价值

目的 分析急性心肌梗死(AMI)患者B型利钠肽(BNP)水平与心功能指标的相关性,选择AMI后心功能的最佳预测指标.方法 顺序入选住院AMI患者230例及正常对照111例,测定BNP.按照心功能Killip分级、左室射血分数(LVEF)和左室舒张末径(LVEDd)进行分组,因BNP不符合正态分布,经自然对数(ln)处理后lnBNP符合正态分布,对比各组间lnBNP的差异;分析lnBNP与心功能指标的相关性;绘制受试者工作特性(ROC)曲线,确定诊断失代偿性左心功能衰竭及心原性休克的最佳指标和阈值.结果 AMI患者lnBNP随着Killip分级(Ⅰ～Ⅲ级)升高和LVEF的降低而梯次显著升高(均P<0.05),在LVEDd55 mill组显著高于≤55 mnl组(均P<0.01);InBNP、LVEDd、LVEF与Killip分级呈线性相关(均P<0.05),其中lnBNP的相关性最好(r=0.53,P<0.05),lnBNP与LVEDd(r=0.17,P<0.05)、LVEF也显著相关(r=-0.41,P<0.01).经多元回归分析显示,仅lnBNP是Killip分级的独立相关因素(P<0.01).ROC曲线分析后显示,lnBNP诊断失代偿性左心衰竭和心原性休克的曲线下面积(AUC)最大(P<0.01),有诊断价值.以BNP=140 ng/L为阈值时,诊断失代偿性左心衰竭的敏感性、阴性预测值和准确度分别为84.9%、75.3%和70.0%;当以BNP=400 ng/L为阈值时,诊断心原性休克的敏感性、阳性预测值和准确度分别为82.8%、72.4%和67.4%.结论 AMI患者BNP水平与Killip心功能分级、LVEDd呈正相关,与LVEF呈负相关,是诊断心力衰竭和排除诊断心原性休克的优良指标.     

急性心肌梗死后不同病程患者的连续心率减速力和心脏猝死差异的比较及相关性分析

目的 探讨急性心肌梗死(AMI)后不同病程患者连续心率减速力(DRs)和心脏猝死差异,并分析其相关性.方法 选取2018年1月至2018年12月于河北北方学院附属第一医院收治的200例AMI后患者作为研究对象,根据梗死后时间不同分为四组:A组(<1个月)、B组(1～3个月)、C组(3～6个月)和D组(>6个月);所有患...     

急性冠状动脉综合征患者窦性心率震荡与左心室功能的关系

目的 研究急性冠状动脉综合征(ACS)患者窦性心率震荡(HRT)现象的变化及与左心室收缩功能的关系.方法 103例ACS患者和62例健康者行24 h动态心电图检查,根据心电图检查结果计算HRT指标:震荡初始值(TO)、震荡斜率(TS)、心率变异(HRV)和全部窦性心搏RR间期的标准差(SDNN).测量左心室射血分数(LVEF)和左心室舒张末期直径(LVEDD).根据心肌酶及心电图的变化将ACS患者分为急性心肌梗死、不稳定心绞痛两个亚组.比较ACS组与对照组及ACS各亚组各变量的差异,分析HRT与LVEF及LVEDD的相关性.结果 (1)ACS组TO高于对照组(0.17±1.40)%与(-0.26±0.99)%,差异有统计学意义(P＜0.05);TS低于对照组[RR间期分别为(0.88±2.51)ms与(2.60±2.76)ms,差异有统计学意义(P＜0.01)].(2)ACS患者两亚组比较,TS、LVEF、LVEDD差异有统计学意义(均P＜0.01).(3)LVEF与TS呈正相关(r=0.21,P＜0.05);与TO负相关(r=-0.26,P＜0.05).结论 ACS患者窦性HRT减弱,提示ACS患者的心脏自主神经调节功能下降,HRT可作为一个评价左心室功能和预后的指标.

Abstract：

Objective To observe the change of sinus heart rate turbulence (HRT) and its relation to left ventricular systolic function (LVSF) in patients with acute coronary syndrome (ACS). Methods The 103 ACS patients and 62 healthy subjects were enrolled in this study, all of them received 24-hour Holter monitor. And the values of turbulence onset (TO), turbulence slope (TS)and heart rate variability (HRV) SDNN were calculated according the Holter records. The clinical information, left ventricular ejection fraction (LVEF) and left ventricular end diastolic diameter (LVEDD) were recorded. Then the ACS patients were divided into acute myocardial infarction (AMI)group and unable angina pectoris (UAP) group according to the cardiac enzymes and electrocardiogram. Results The value of TO was significantly higher in ACS group than in control group [(0.17±1.40)％ vs. (- 0.26±0.99)％, P＜0.05], and TS was significantly lower in ACS group than in control group [R-R interval:(0.88±2.51) ms vs. (2.60±2.76) ms, P＜0.01].There were significant differences in TS, LVEF and LVEDD between AMI group and UAP group (all P＜0.01), but there were no differences in HRV and TO between the two groups. TS was positively correlated with LVEF (r=0.21, P＜0.05), while TO was negatively correlated with LVEF (r=-0.26, P＜0.05) by Spearman correlation analysis. Conclusions HRT is significantly blunted in ACS patients and can evaluate cardiac autonomic function. It may be as a predictor of LVSF in ACS patients.     

Cardiac and plasma catecholamine responses to exercise in patients with type 2 diabetes: prognostic implications for cardiac-cerebrovascular events

BACKGROUND: Patients with diabetes mellitus have an altered exercise plasma catecholamine response, which may be related to the abnormal sympathoadrenal function and autonomic neuropathy. Presence of autonomic neuropathy is associated with poor prognosis, but relationship between exercise plasma catecholamine and prognosis has not been investigated. This study determined if altered plasma catecholamine response to exercise was associated with cardiac-cerebrovascular events. METHODS: Forty patients with type 2 diabetes without apparent macrovascular complications and 30 control subjects performed treadmill exercise with serial measurements of plasma norepinephrine and epinephrine. Clinical, exercise, and catecholaminergic variables considered relevant to the cardiac-cerebrovascular events were examined by Cox regression model. Analysis of 24-hour heart rate variability was performed in a subgroup of patients. RESULTS: During 7.2 years, 8 patients, but no control subjects, had events (3 myocardial and 5 cerebral infarctions). Compared with Event(-) patients, Event(+) patients had: (1) orthostatic hypotension; (2) lower peak exercise heart rate; (3) lower plasma norepinephrine immediately after exercise; and (4) lower plasma epinephrine at peak exercise. High frequency components in heart rate variability analysis were diminished in Event(+) patients. Multivariate analysis showed that peak heart rate (P = 0.04) and plasma epinephrine at peak exercise (P = 0.03) were independent predictors of subsequent events. CONCLUSIONS: These data suggest that chronotropic incompetence and lower plasma epinephrine response to exercise are associated with high risk of cardiac-cerebrovascular events in patients with type 2 diabetes.     

急性心肌梗死患者早期血糖增高的临床特点及其预后

目的　探讨急性心肌梗死 (AMI)患者早期血糖增高特点及其预后。方法　回顾性分析住院AMI患者 2 0 6例 ,分为单纯AMI、合并高血压 (HT)、合并 2型糖尿病 (DM )以及DM合并HT组。观察其心功能 (Killip)、恶性心律失常及病死率差别。 结果　 ( 1)无DM的AMI患者早期血糖增高出现率为 4 8 2 % ,多见于女性病人 ,梗死部位多为前壁 ;( 2 )合并显著血糖应激反应的单纯AMI患者其预后较无应者差 (住院死亡率 :2 5 %vs 3 4 4 % ,P <0 0 5 ) ,而与AMI DM HT或AMI DM者相近 (住院死亡率 :2 5 %vs 30 77%vs 31 2 5 % ,P >0 0 5 ) ;( 3)AMI患者预后与早期血糖水平、心功能和恶性心律失常成正相关 (血糖r =0 19,心功能r =0 14 ,恶性心律失常r =0 4 0 ,P均 <0 0 1)。结论　AMI早期血糖增高 ,提示预后差 ,尤其对合并DM、HT及显著血糖增高者 ,应积极治疗     

Correlation of heart rate variability with cardiac functional and metabolic variables in cyclists with training induced left ventricular hypertrophy

OBJECTIVE: To examine the correlation between heart rate variability and left ventricular mass in cyclists with an athlete's heart. METHODS: Left ventricular mass and diastolic function were determined at rest and myocardial high energy phosphates were quantified at rest and during atropine-dobutamine stress in 12 male cyclists and 10 control subjects, using magnetic resonance techniques. Ambulatory 24 hour ECG recordings were obtained, and time and frequency domain heart rate variability indices were computed. RESULTS: In the cyclists, the mean of all RR intervals between normal beats (meanNN), the SD of the RR intervals, and their coefficient of variation were significantly greater than in control subjects (p < 0.01, p < 0.01, and p < 0.05, respectively). For cyclists and control subjects, only meanNN correlated with left ventricular mass (r = 0.48, p = 0.038). The heart rate variability indices that correlated with functional or metabolic variables were: meanNN v E/A peak (the ratio of peak early and peak atrial filling rate) (r = 0.48, p = 0.039); the root mean square of successive differences in RR intervals among successive normal beats v E/A area (ratio of peak early and peak atrial filling volume) (r = 0.48, p = 0.040); percentage of successive RR intervals differing by more than 50 ms v the phosphocreatine to ATP ratio at rest (r = 0.54, p = 0. 017); and the SD of the average RR intervals during all five minute periods v the phosphocreatine to ATP ratio during stress (r = 0.60, p = 0.007). CONCLUSIONS: Highly trained cyclists have increased heart rate variability indices, reflecting increased cardiac vagal control compared with control subjects. Left ventricular mass has no major influence on heart rate variability, but heart rate variability is significantly correlated with high energy phosphate metabolism and diastolic function.     

B型钠尿肽对心肌梗死患者心功能评估的研究

目的观察急性心肌梗死（AMI）患者血B型钠尿肽（BNP）水平的变化特点,探讨BNP对评估AMI患者心力衰竭及心肌缺血严重程度的临床意义。方法入选住院AMI患者93例及正常对照组50例进行BNP的床旁快速检测,并行超声心动图测定左心室射血分数（LVEF）和左心室舒张末期内径（LVEDd）,按照心肌梗死Killip心功能分级分为Ⅰ—Ⅳ级,按照梗死部位分为广泛前壁AMI组、前壁和／或前间壁AMI组、下壁和／或后壁AMI组,根据ST段有无抬高分为ST段抬高型心肌梗死（STEMI）和非ST段抬高型心肌梗死（NSTEMI）,计算各组内的BNP值并进行统计学分析。结果随着AMI患者Killip心功能分级的递增,BNP水平不断增高（除KillipⅠ级与对照组BNP浓度比较P〉0．05,其余各组之间BNP差异有统计学意义P〈0．05）,LVEF随着Killip分级递增而减少,与BNP呈中度负相关（r=-0．79,P〈0．05）而LVEDd逐渐增大与BNP呈高度正相关（r=0．96,P〈0．05）。广泛前壁AMI组BNP浓度〉前壁和／或前间壁AMI组〉下壁和／或后壁AMI组。STEMI组和非NSTEMI组BNP水平差异无统计学意义。结论床旁快速测定BNP浓度可作为判定AMI患者心功能状况及心肌缺血严重程度的重要生化指标之一。