QT离散度在冠心病患者运动试验中的意义

目的探讨平板运动试验中冠心病患者与冠状动脉正常者ＱＴ离散度（ＱＴｄ）变化的意义。方法分析经冠状脉动（冠脉）造影证实的１３例冠心病患者与１７例冠脉造影正常者平板运动试验前、试验中ＳＴ段下移０１ｍＶ以上或出现典型心绞痛症状或达亚极量心率时以及运动后体表１２导联心电图ＱＴｄ变化。结果运动前、中、后冠心病组ＱＴｄ分别为４６２±２０１ｍｓ，７１９±２０．４ｍｓ及５１．２±１４．５ｍｓ；而冠状动脉正常组分别为３２．３±６．６ｍｓ，３０．９±９．２ｍｓ与２９．４±８．５ｍｓ，两组相比Ｐ均＜０．０１；冠心病组ＱＴｄ运动中与运动前后相比Ｐ均＜０．０１，而冠脉正常组差异无显著性；以运动中ＱＴｄ≥６０ｍｓ判为异常，诊断冠心病的敏感性为９２．３％，特异性１００％，准确性９６．７％。结论冠心病患者运动试验中ＱＴｄ进一步显著增加，ＱＴｄ是运动试验中诊断冠心病心肌缺血敏感而特异的指标。     

女性运动试验前后QT离散度变化对冠心病诊断的价值

探讨女性病人运动试验前、后ＱＴ离散度（ＱＴｄ）的变化和其对冠心病诊断的价值。对临床上以胸痛为主诉的８４例女性病人,先后行运动试验和冠状动脉造影检查,并测量运动试验前、后体表１２导联心电图ＱＴｄ。结果：在冠心病病人中,无论运动试验阳性还是阴性,运动试验后ＱＴｄ明显大于运动试验前,差异有显著性（５３．５９±１６．９３ｍｓｖｓ３２．０５±１４．１８ｍｓ,Ｐ＜０．０１）;在非冠心病病人中运动试验前、后ＱＴｄ无显著性差异（３０．９８±１２．００ｍｓｖｓ２９．２７±１２．３３ｍｓ,Ｐ＞０．０５）。以运动试验后即刻和运动试验前ＱＴｄ的差值≥２０ｍｓ作为指标,诊断冠心病的敏感性为８７．１８％、特异性为８０．００％、准确性为８３．３３％。结果提示运动试验与ＱＴｄ相结合可提高对女性冠心病诊断的敏感性、特异性和准确性。     

心肌缺血和冠状动脉病变对QTc离散度的影响

为探讨ＱＴｃ离散度（ＱＴｃｄ）与心肌缺血和冠状动脉（简称冠脉）病变程度的关系，分析２８例冠脉正常和５７例冠心病患者１２导联心电图的ＱＴｃｄ。结果示：冠心病组ＱＴｃｄ较冠脉正常组显著增大（４６．７±１２．６ｍｓｖｓ２６．３±１０．９ｍｓ，Ｐ＜０．０１）；不稳定型心绞痛ＱＴｃｄ明显大于稳定型心绞痛者（５４．６±１３．７ｍｓｖｓ４２．３±１４．１ｍｓ，Ｐ＜０．０５）；双支病变与单支病变以及三支病变与双支病变相比，ＱＴｃｄ均有显著增大（４８．７±１３．２ｍｓｖｓ３５．７±１１．９ｍｓ及５９．６±１５．１ｍｓｖｓ４８．７±１３．２ｍｓ，Ｐ均＜０．０５）。提示心肌缺血是引起冠心病患者ＱＴｃｄ增大的主要原因之一，ＱＴｃｄ的变化对于判断心肌缺血和冠脉病变程度有一定价值。     

QT离散度与冠心病的关系

根据１３２例患者冠脉造影（ＣＡＧ）结果，结合临床诊断进行分组并分别从体表静息标准１２导联心电图上测量得出ＱＴ间期离散度（ＱＴｄ）与ＱＴｃ间期离散度（Ｑｔｃｄ）。统计学处理结果显示：ＱＴｄ、ＱＴｃｄ在冠脉正常组（Ｃ组）分别是２２．７±１９．７ｍｓ与２８．０±１５．９ｍｓ，冠脉病变组（Ｂ组）分别是３６．４±１６．６ｍｓ与４１．０±１７．５ｍｓ，与前组比较有显著差异（Ｐ＜０．０１）。急性心肌梗死组（Ａ组）ＱＴｃ、ＱＴｃｄ分别是６４．８±２５．４ｍｓ、７３．１±２９．４ｍｓ，与前两组比较均有明显差异（Ｐ＜０．０１）。结果显示：不但急性心肌梗死组ＱＴｄ增大，而且冠脉病变组ＱＴｄ也增大。故认为心肌缺血是ＱＴｄ增大的重要原因之一，且可能与缺血产生速度和严重程度有关。     

平板运动试验中的QT离散度诊断冠心病的价值

目的了解平板运动试验中的ＱＴ离散度（ＱＴｄ）和校正ＱＴ离散度（ＱＴｃｄ）变化对冠心病心肌缺血的诊断价值。方法分析经冠脉造影证实的３０例冠心病患者与２３例冠脉造影正常者平板运动试验前、试验中ＳＴ段下移最大时或最大负荷心率时（无ＳＴ段下移时）及运动后体表１２导联心电图ＱＴｄ、ＱＴｃｄ变化。结果冠心病组和冠脉正常组ＱＴｄ与ＱＴｃｄ比较Ｐ均〈０．０１;冠心病组ＱＴｃｄ运动中与运动前、后比Ｐ均〈０．０１,Ｑ     

对QT离散度实质的探讨

为探讨ＱＴ离散度（ＱＴｄ）的真实意义，观察１３９例急性心肌梗死（ＡＭＩ，ＡＭＩ组）及１０９例正常人（对照组）的最长ＱＴ间期（ＱＴｍａｘ）、校正ＱＴｍａｘ（ＱＴｃｍａｘ）及ＱＴｄ的变化。结果：①ＡＭＩ组的ＱＴｍａｘ、ＱＴｃｍａｘ和ＱＴｄ均显著高于对照组（分别为４２２．６０±３０．５１ｍｓｖｓ３８２．４６±２３．４０ｍｓ、４６０．２１±２８．９６ｍｓｖｓ３８８．５１±２０．１５ｍｓ、５９．８０±２８．４０ｍｓｖｓ３９．４３±１２．２１ｍｓ，Ｐ均＜０．００１）。②ＡＭＩ组中发生严重室性心律失常（ＶＡ）患者（１１４例）的ＱＴｍａｘ、ＱＴｃｍａｘ、ＱＴｄ与无ＶＡ的患者（２５例）相比，均有显著差异（分别为４４８．５８±３３．４０ｍｓｖｓ４１６．１０±３５．３０ｍｓ、４８１．４３±３５．１７ｍｓｖｓ４３９．６０±２７．１０ｍｓ、６６．９０±２０．７２ｍｓｖｓ４８．３２±２３．６１ｍｓ，Ｐ均＜０．００１）。认为ＡＭＩ时ＱＴｄ系Ｔ向量环在不同导联上的“投影”差异所引起的，其异常的本质是ＱＴ间期延长     

平板运动试验诱发心肌缺血QT离散度的变化及意义

为探讨平板运动试验 (ＥＥＴ)中ＱＴｄ的变化及意义。比较ＥＥＴ诱发心肌缺血运动前、后ＱＴｄ、ＱＴｃｄ的变化 ,并与冠脉造影结果比较。心肌缺血组 (Ａ组 )在运动前ＱＴｄ、ＱＴｃｄ与正常对照组 (Ｂ组 )ＱＴｄ、ＱＴｃｄ比较变化不明显 ;运动后ＱＴｄ、ＱＴｃｄ明显延长 (Ｐ <0 .0 0 1)。与冠脉造影结果比较 ,用ＥＥＴ诊断冠心病心肌缺血的敏感性为 90 % ,特异性为 5 3 % ,以ＱＴｄ、ＱＴｃｄ≥ 60ｍｓ为标准诊断冠心病心肌缺血的敏感性为 95 % ,特异性为94%。ＥＥＴ阳性时将ＳＴ段下移与ＱＴｄ、ＱＴｃｄ延长两者结合起来评价运动试验结…     

不同临床类型冠心病的QTc离散度

分析１０９例经冠状动脉（简称冠脉）造影证实的不同类型冠心病患者ＱＴｃ离散度（ＱＴｃｄ），以４１例临床疑有冠心病而冠脉造影正常者作对照。结果显示：冠心病各组ＱＴｃｄ均明显大于对照组（６２．２９±２２．１９ｍｓ、７３．４４±２３．７７ｍｓ、１００．００±２０．１９ｍｓｖｓ３５．１９±１４．１８ｍｓ），Ｐ均＜０．００１。陈旧性心肌梗塞组的ＱＴｃｄ明显大于心绞痛组（７３．４４±２３．７７ｍｓｖｓ６２．２９±２２．１９ｍｓ），Ｐ＜０．０５；陈旧性心肌梗塞合并室壁瘤组ＱＴｃｄ显著大于陈旧性心肌梗塞组（１００．００±２０．１９ｍｓｖｓ７３．４４±２３．７７ｍｓ），Ｐ＜０．００１。前壁与下壁心肌梗塞患者ＱＴｃｄ比较无显著性差异（７３．５０±２４．３４ｍｓｖｓ７３．３３±２３．８７ｍｓ，Ｐ＞０．０５）。冠脉单支、双支及三支病变者ＱＴｃｄ（分别为７６．１８±２４．２５ｍｓ、７８．００±２８．５８ｍｓ和８０．２１±２５．１４ｍｓ）比较无显著性差异，Ｐ＞０．０５。提示不同临床类型冠心病患者心肌复极存在明显差异，陈旧性心肌梗塞伴室壁瘤形成者ＱＴｃｄ增大最显著，ＱＴｃｄ与梗塞部位及冠脉病变支数无关。     

QT离散度对冠心病的诊断价值（附15例分析）

因运动试验中较高的假阳性率使其在冠心病的诊断中受到很大限制。已有研究表明 ,ＱＴ离散度 (ＱＴｄ)是代表心室复极的差异 ,冠心病者ＱＴｄ明显增大 ,且在心脏负荷试验后ＱＴｄ显著增加 ,而正常对照组无变化。本文对冠心病组 (Ａ组 )及对照组 (Ｂ组 )平板运动试验 (ＥＴＴ)前、中、后ＱＴｄ的变化作分析 ,报告如下。1　资料与方法Ａ组 :1999年 8月～ 2 0 0 0年 8月在我院确诊的冠心病者 15例 ,诊断标准为 :选择性冠脉造影后采用Ｊｕｄｋｉｎ′ｓ法 ,至少 1支主要冠脉或其主要分支狭窄≥5 0 %者。男 11例、女 4例 ,平均年龄 (5 2 .7± 9.0 )…     

多巴酚丁胺负荷超声心动图试验对冠心病诊断价值的评价

以冠状动脉造影为标准，对３９例冠脉狭窄≥５０％的冠心病人与１３例冠脉狭窄＜５０％或腔径正常的临床可疑冠心病人作为＂正常＂对照，用多巴酚丁胺负荷超声心动图（Ｄｏｂｕ－Ｅｃｈｏ）和心电图（Ｄｏｂｕ－ＥＣＧ）试验对冠心病的诊断价值进行了评价。发现Ｄｏｂｕ－Ｅｃｈｏ的敏感性为９２．３％，特异性为８４．６％，准确度为９０．４％；而Ｄｏｂｕ－ＥＣＧ的敏感性为３０．８％，特异性７６．９％，准确度４２．３％。试验中未发现严重不良反应发生。结果认为：Ｄｏｂｕ－Ｅｃｈｏ是安全、准确性好的无创性冠心病诊断试验，可推广临床应用。     

平板运动试验中IQTd诊断冠心病的价值

目的　评价用心率调整QTd指标 (IQTd)在平板运动试验中对冠心病的诊断价值。方法　 4 3例患者在冠状动脉造影前行平板运动试验 (ETT) ,测量其运动前、运动中与ST段下移最大时或最大负荷心率时 (无ST段下移者 )QTd、校正QTd(QTdr、QTcdr、QTdp、QTcdp) ,分别计算IQTd和IQTcd。ETT后 1周内行冠状动脉造影 (CAG) ,根据CAG结果分为冠心病 (CAD)组 2 3例和冠状动脉正常 (NCAD)组 2 0例。结果　运动前的QTdr和QTc dr在CAD与NCAD组间无显著差别。在冠状动脉正常组 ,运动过程QTdp和QTcdp无显著增加 ,而在冠心病组QTdp和QTcdp有显著性增加 (P <0 0 0 1)。在运动过程中 ,QTdp、QTcdp、IQTd、IQTcd在CAD与NCAD组间有明显差异。在NCAD组QTdp、QTcdp、IQTd、IQTcd95 %上限值分别为 74ms、86ms、0 .17ms/bpm和0 2ms/bpm。用其界值作为诊断标准 ,其特异性显著高于ST段压低 ,IQTd和IQTcd的敏感性和准确性显著高于ST压低 (P <0 0 5 )。结论　提示IQTd、IQTcd可作为平板运动试验中诊断冠心病敏感、准确和特异的指标     

运动试验阴性的男性患者QT离散度的变化对冠心病的诊断价值

目的 观测运动试验中QT离散度的改变是否能够增加运动试验对冠心病的检出率。方法分析60例因有明显的临床指征而行冠状动脉造影的男性患者,术前患者运动试验均未诱发ST段压低。其中34例为两年期间连续冠状动脉造影结果未见显著狭窄者(对照组),26例为两年期间连续冠状动脉狭窄者(实验组)。两组分别测量运动试验前及运动试验后1、3、5分钟12导心电图最长和最短的QT间期的差值,即QT离散度(QTd)。结果 运动停止即刻实验组QTd明显较对照组大。以运动停止即刻QTd大于60ms为指标诊断冠心病的敏感性为84.6％,特异性为76.5％,符合率为87.7％。结论 对运动试验未能诱发出ST段压低的人群。以运动停止即刻QTd大于60ms作为诊断冠心病的指标,可以提高诊断的准确性。     

美托洛尔对冠心病患者QT离散度的影响

为探讨β－受体阻断剂美托洛尔（Ｍｅｔｏｐｒｏｌｏｌ）对冠心病（ＣＡＤ）患者ＱＴ离散度（ＱＴｄ）的影响，采用随机分组、单盲处理、前瞻性研究的方法，观察６２例ＣＡＤ患者Ｍｅｔｏｐｒｏｌｏｌ治疗前、后ＱＴｄ及ＲＲ间期、心率校正ＱＴ间期离散度（ＱＴｃｄ）、最大ＱＴ间期（ＱＴｍａｘ）、最小ＱＴ间期（ＱＴｍｉｎ）的变化。试验组Ｍｅｔｏｐｒｏｌｏｌ治疗后ＣＡＤ患者ＱＴｍｉｎ延长（３８６±３１．８ｍｓｖｓ３５２±２２．４ｍｓ，Ｐ＜０．０１），而ＱＴｍａｘ无明显改变（４３０±３５．６ｍｓｖｓ４２３±３４．９ｍｓ，Ｐ＞０．０５），ＱＴｄ、ＱＴｃｄ则显著缩小（分别为４４±１２．９ｍｓｖｓ７１±２８．６ｍｓ，４５±１１．５ｍｓｖｓ７９±３４．９ｍｓ，Ｐ均＜０．０１）。对照组治疗前、后ＱＴｄ、ＱＴｃｄ、ＱＴｍａｘ、ＱＴｍｉｎ均无改变（Ｐ＞０．０５）。表明Ｍｅｔｏｐｒｏｌｏｌ通过显著延长ＣＡＤ患者的ＱＴｍｉｎ缩小心肌复极化离散的程度，使心肌复极化趋向同步，这有利于防止恶性室性心律失常的发生     

Usefulness of Seismocardiography for the Diagnosis of Ischemia in Patients with Coronary Artery Disease

Background: Seismocardiography (SCG) is a useful method for the detection of exercise‐induced changes in cardiac muscle contractility which may occur during myocardial ischemia. The aim of this study was to compare the diagnostic accuracy of SCG with electrocardiographic exercise test (ETT) for diagnosis of ischemia in patients with angiographically proved coronary artery disease (CAD). Methods: Seventy‐seven male patients with CAD without myocardial infarction (MI), mean age 51 ± 9 years, were subjected to SCG and ETT. A gender‐matched control group consisted of 30 healthy volunteers aged 34 ± 7 years. SCG was done simultaneously with resting supine 12‐lead electrocardiography before and immediately after a symptom‐limited ETT. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) of SCG were compared with ETT. Moreover, the diagnostic accuracy of both the methods was compared, with coronary angiography being the reference for the analysis. Results: SCG was more sensitive (61.1% vs 44.2%, P < 0.05) and accurate (70% vs 61%, P < 0.05) method for detecting ischemia caused by coronary stenosis ≥50%, at least in one coronary artery compared to the ETT. However, ETT had better specificity than SCG (82.4% vs 76%, P < 0.05). The PPV and NPV of SCG were significantly better than those obtained with ETT (77.9% vs 76%, P < 0.05 and 63.4% vs 53.8%, P < 0.05, respectively). Moreover, the concordant results of SCG and ETT improved the diagnostic accuracy of both methods. Conclusions: SCG appeared to be more sensitive for detecting ischemia caused by more than ≥50% stenosis of the main coronary artery compared to an electrocardiographic stress test. SCG was a useful ETT adjunct for selecting patients requiring coronary angiography.     

运动试验时QT间期离散度诊断冠心病的价值

目的探讨QT离散度（QTd）在运动试验中的变化,及其对冠心病心肌缺血的诊断价值。方法 68例临床诊断或疑诊为冠心病的患者先后行平板运动试验（简称运动试验）及冠状动脉造影（简称冠脉造影）检查。结果 47例运动试验阳性者中30例确诊为冠心病;21例运动试验阴性者中19例冠状动脉正常。冠心病组与冠脉正常组运动前、中、后QTd分别为42.38±19.28 ms、70.58±19.45 ms、50.14±13.56 ms及31.18±6.25 ms、30.01±9.05 ms、28.24±8.12 ms,两者比较,p均〈0.01。冠心病组运动前、后与运动中QTd比较,差异有显著性,p〈0.005;而冠脉正常组QTd变化无显著性。以运动中QTd≥60 ms为异常,诊断冠心病的敏感性为90.9%、特异性100%、准确性94.9%。结论提示运动试验中QTd增加可作为诊断冠心病心肌缺血的敏感而特异的指标。     

Changes in QT dispersion during adenosine infusion

BACKGROUND: QT dispersion (QTd) measurement during treadmill stress testing has been to shown to improve the accuracy of exercise electrocardiogram (ECG) in the detection of significant coronary artery disease (CAD). HYPOTHESIS: The aim of this study was to determine whether adenosine-induced changes in QTd could predict significant CAD and to assess its efficacy as a diagnostic index in patients undergoing adenosine stress test. METHODS: QT interval measurements were made in 57 consecutive patients undergoing adenosine sestamibi stress test. Patients with an abnormal stress test underwent coronary angiography. Patients with significant disease by coronary angiography (> 70% stenosis) were classified as having CAD (Group 1), and those with normal stress images and/or normal coronaries by angiography were classified as having no CAD (Group 2). RESULTS: QT dispersion increased from 28.2 +/- 4.5 to 43.8 +/- 4.5 ms with a delta QTd of 15.53 +/- 3.68 in Group 1 (p = 0.001) and from 28.4 +/- 2.6 to 34.8 +/- 2.8 ms with a delta QTd of 6.58 +/- 2.21 ms in Group 2 (p = 0.006). Patients in Group 1 had a significantly higher increase in QTd (delta QTd) than the patients in Group 2 (p < 0.03). Addition of delta QTd (> 10 ms) to the ST depression during adenosine infusion would increase the sensitivity of the ECG from 23 to 65% and decrease the specificity from 91 to 70% for diagnosis of significant CAD. CONCLUSIONS: delta QTd is significantly more prolonged in patients with CAD during adenosine infusion. It increases the sensitivity of the stress ECG in diagnosis of CAD during adenosine infusion when used as an adjuvant index.     

QT dispersion plus ST-segment depression: a new predictor of restenosis after successful percutaneous transluminal coronary angioplasty.

BACKGROUND: ST-segment depression during exercise testing is frequently observed in the absence of restenosis after percutaneous transluminal coronary angioplasty (PTCA). HYPOTHESIS: With the goal of improving the prediction of restenosis after PTCA, we evaluated the usefulness of ST-segment depression plus QT dispersion (QTd = QTmax - QTmin) during treadmill stress test. METHODS AND RESULTS: Fifty-six patients (37 men, 19 women, mean age 51 +/- 14 years) were evaluated with treadmill exercise testing and coronary angiography 7 +/- 5 months after PTCA. Treadmill test was positive in 30 patients and negative in 26 patients. At coronary angiography, restenosis was present in 16 patients with positive exercise electrocardiogram (ECG) and in 6 patients with negative exercise ECG. Fourteen patients with a positive stress test did not have restenosis. There was no difference in QTd values between groups at baseline (p > 0.05). Exercise QTd was 63 +/- 9 ms in patients with positive exercise test, 54 +/- 18 ms in patients with negative exercise test (p = 0.003), 71 +/- 13 ms in patients with restenosis, and 53 +/- 17 ms in patients without restenosis (p = 0.001). ST-segment depression during the stress test determined restenosis with a sensitivity of 80% and a specificity of 58%. Sensitivity and specificity of QTd of > or = 60 ms for prediction of restenosis were 83 and 61%, respectively. When QTd of > or = 60 ms was added to ST-segment depression as a condition for positive test, the sensitivity and specificity increased to 91 and 78%, respectively. QT dispersion plus ST-segment depression had higher sensitivity and specificity than either QTd or ST-segment depression alone (p < 0.05). CONCLUSION: The addition of QTd to ST-segment depression during exercise test improves the diagnostic value and can be used as a noninvasive tool in the diagnosis of restenosis after PTCA.     

同时行平板运动试验、QT离散度检查对冠心病诊断价值的研究

探讨同时行平板运动试验 (ETT)和测量QT间期离散度 (QTd)对反映冠状动脉病变的价值及应用前景。与冠状动脉造影结果对照分析 83例临床诊断或疑诊为冠心病患者的ETT、QTd(试验中ST段下移最大时或最大负荷心率时 )的结果。结果 :①ETT、QTd和系列法双项复合试验的灵敏性分别为 71.7%、79.2 %和 5 6 .6 % ;特异性分别为70 %、80 %和 96 .7% ;阳性预测值分别为 80 .9%、87.5 %和 96 .8% ;阴性预测值分别为 5 8.3%、6 8.6 %和 5 5 .8%。②ETT和QTd的灵敏性主要取决于受检人群、冠状动脉病变的支数和位置 ,QTd诊断单支、三支和前降支血管病变的灵敏性高于ETT(分别为 71.4 %vs 5 7.1% ;10 0 %vs 90 % ;92 .3%vs 76 .9% ) ,但均无统计学意义。结论 :同时行平板运动试验、QTd检查诊断冠心病较其单项检测具有更高的特异性和阳性预测值。     

血红蛋白水平对平板运动试验阳性结果诊断价值的影响

目的研究血红蛋白水平对平板运动试验阳性结果诊断价值的影响。方法选择2010年1月到2016年12月因胸痛或胸闷怀疑冠心病行平板运动试验阳性和冠状动脉造影者300例,造影结果显示主要血管狭窄≥70%的137例(阳性组),<70%163例(阴性组),分析比较临床资料及对运动平板试验阳性结果预测值的影响。结果阳性组的血红蛋白、尿酸、肌酐、甘油三酯、男性比例、吸烟比例和高血压比例明显高于阴性组,红细胞分布密度(RDW)、高密度脂蛋白胆固醇(HDL-C)低于阴性组,差异均有统计学意义(均P<0.05)。单因素和多因素logistic回归分析血红蛋白是平板运动试验阳性患者预测冠心病的独立预测因素。ROC曲线分析,血红蛋白曲线下面积0.702(P<0.01),血红蛋白≥137g/L,其敏感度为60.58%,特异度为74.85%。结论血红蛋白水平会影响平板运动试验阳性结果的诊断价值。