导管射频消融室上速心肌复极离散度的变化

目的：探讨导管射频消融（RFCA）室上速（PSVT）时心肌复极离散度的变化。方法：记录80例射频及射频成功后的12导联同步体表心电图,测定QTd、JTd间期。结果：室上速射频前、后的QTd、JTd无显差异（P＞0．05）。结论：射频消融对PSVT患的心肌复极离散度的变化无影响。     

室性心动过速患者QT离散度变化的临床意义

目的　探讨室性心动过速 (VT)患者 QT离散度 (QTd)变化的意义。方法　对正常对照组 (35例 )和 VT组 (31例 )记录 12导联同步心电图 ,人工测量 QT间期 ,计算 QTd。结果　与对照组相比 ,VT组 12导联QTd明显增加 (P<0 .0 1) ,但两组之间存在很大交叉 ,无法建立正常参考值 ;QT间期明显延长 (P<0 .0 1) ,两组QTmax多见于 V2 、V3、V4 和 V5导联 (分别为 75 .0 %、77.8% ) ,两组 QTmax、QTmin导联分布无显著差异 (P>0 .0 5 )。结论　 VT患者的 QTd不能代表心肌复极的区域性差异 ,仅可作为心肌复极异常简单、粗略的指标。     

QT离散度测量的电生理基础

ＱＴ离散度 (ＱＴｄ)一直是一个有争议的问题。正是有争议 ,才使得研究不断深入 ,更加深了我们对心电现 象的进一步认识 ;影响ＱＴｄ的因素可能很多 ,但不管怎样 ,仅ＱＴ间期延长或Ｔ波变化本身也具有临床意义。为此 , 本刊邀请有关专家就ＱＴｄ有关问题进行阐述 ,旨在介绍有关概念、研究进展、发展方向。     

QT离散度及其临床意义

ＱＴ离散度及其临床意义成都市心血管病研究所杜传礼，王伟综述ＱＴ间期离散度（ＱＴｄ）是指心电图各导联间ＱＴ时限变异的程度［１］，此现象最早由Ｃａｍｐｂｅｌｌ提出［２］，它是由于心室肌肉复极不一致引起。通常测量的方法是采用体表常规１２导联心电图上最长的Ｑ...     

QT离散度

QT离散度(QTd)系指体表12导联心电图各导联QT间期存在的差异,这一现象早被人们发现,但未重视。直至1985年,Campbell等发现心电图导联间存在的QT间期差异是有规律性的,遂提出QT离散度这一概念。 概述 体表心电图与心肌细胞单相动作电位有着密切的关系。心电图的QT间期相当于动作电     

QT离散度的昼夜变异性

ＱＴｄ是新近发展起来的 1项反映心室复极离散程度的指标 ,增大时反映心室复极不平衡性增加 ,可能导致严重的心律失常 ,甚至猝死[1、2 ] 。许多临床研究表明某些心血管事件的发生 (如心肌缺血、心源性猝死、心肌梗死 )存在一定的昼夜节律[3～ 5] ,可能与心脏自主神经活动的昼夜节律改变有关。晚近报道ＱＴ间期存在昼夜节律 ,并受自主神经活动所调节[6、7] ,对ＱＴｄ的变异性研究国内则鲜有报道。本文以 12导联 2 4ｈＤＣＧ观察正常人ＱＴｄ变异情况 ,报道如下。1　资料与方法1.1　对象　男 2 4例、女 2 6例 ,年龄 (5 5± 11)岁。均为窦性心…     

正常成人区域性QT离散度及临床意义探讨

本研究按心肌梗死 (ＭＩ)的定位诊断将 12导联心电图划分为数个区域 ,把各区域中最大、最小ＱＴ间期的差值 ,称为区域性ＱＴ离散度 (ＱＴｒｄ) ,探讨ＱＴｒｄ的临床意义。1.资料与方法 :资料为 2年来自愿体检合格的正常成人 ,常规同步记录 12导联心电图 ,测量 12导联ＱＴ间期 ,统计其ＱＴ离散度 (ＱＴｄ) ;将 12导联心电图分为Ⅰ、ａＶＬ ,Ⅱ、Ⅲ、ａＶＦ ,Ｖ1～ 3 ,Ｖ2～ 4 ,Ｖ5、6共 5个区域 ;统计各区域的ＱＴｒｄ。按不同性别分为 16～ 2 4岁 ,2 5～ 44岁 ,45岁以上 3组 ,各年龄组又分为心率 6 0～ 79次 /ｍｉｎ和 80～ 99次 /ｍｉｎ两…     

急性心肌梗塞时QT离散度的临床意义

QT离散度(QTd)是指心电图各导联间QT变异的量度。85年由Campbell首先提出。我们对38例急性心梗的QTd、QTcd、QTIcd、JTd、JTcd、JTtcd进行测量，并与36例健康^比较。结果显示在AMI早期24小时以内的心电图与对照组比较QTd即出现区域性的显差异P<0．001。QTmax、JTmax存在于梗塞或     

QT离散度

ＱＴ离散度陈义汉，龚兰生数十年以前人们就发现ＱＴ间期存在导联间的差异，但一直被视为记录伪差所致，而未予重视。１９８５年Ｃａｍｐｂｅｌｌ等发现不同导联间ＱＴ间期的差异有其规律性，因而提出了ＱＴ离散度（ＱＴｄｉｓｐｅｒｓｉｏｎ）这个概念。然而，直到１９９...     

QT离散度

体表心电图各导联间ＱＴ间期的差异称ＱＴ离散度。它可能反映了心室肌复极的非同步性，对于通过心电图测算ＱＴ离散度评价心脏病发生猝死的危险性，本文作了综述。     

QT dispersion does not represent electrocardiographic interlead heterogeneity of ventricular repolarization

INTRODUCTION: QT dispersion (QTd, range of QT intervals in 12 ECG leads) is thought to reflect spatial heterogeneity of ventricular refractoriness. However, QTd may be largely due to projections of the repolarization dipole rather than "nondipolar" signals. METHODS AND RESULTS: Seventy-eight normal subjects (47+/-16 years, 23 women), 68 hypertrophic cardiomyopathy patients (HCM; 38+/-15 years, 21 women), 72 dilated cardiomyopathy patients (DCM; 48+/-15 years, 29 women), and 81 survivors of acute myocardial infarction (AMI; 63+/-12 years, 20 women) had digital 12-lead resting supine ECGs recorded (10 ECGs recorded in each subject and results averaged). In each ECG lead, QT interval was measured under operator review by QT Guard (GE Marquette) to obtain QTd. QTd was expressed as the range, standard deviation, and highest-to-lowest quartile difference of QT interval in all measurable leads. Singular value decomposition transferred ECGs into a minimum dimensional time orthogonal space. The first three components represented the ECG dipole; other components represented nondipolar signals. The power of the T wave nondipolar within the total components was computed to measure spatial repolarization heterogeneity (relative T wave residuum, TWR). QTd was 33.6+/-18.3, 47.0+/-19.3, 34.8+/-21.2, and 57.5+/-25.3 msec in normals, HCM, DCM, and AMI, respectively (normals vs DCM: NS, other P < 0.009). TWR was 0.029%+/-0.031%, 0.067%+/-0.067%, 0.112%+/-0.154%, and 0.186%+/-0.308% in normals, HCM, DCM, and AMI (HCM vs DCM: NS, other P < 0.006). The correlations between QTd and TWR were r = -0.0446, 0.2805, -0.1531, and 0.0771 (P = 0.03 for HCM, other NS) in normals, HCM, DCM, and AMI, respectively. CONCLUSION: Spatial heterogeneity of ventricular repolarization exists and is measurable in 12-lead resting ECGs. It differs between different clinical groups, but the so-called QT dispersion is unrelated to it.     

急性心肌梗死QT离散度变化与室壁运动异常的关系

目的 研究急性心肌梗死（ＡＭＩ）患者ＱＴ离散度（ＱＴｄ）变化与室壁运动异常（ＲＷＭＡ）的关系。方法 应用多普勒超声心动图和１２导联同步记录心电图测定,４３例ＡＭＩ患者（ＡＭＩ组）和３０例劳力型心绞痛患者（对照组）ＲＷＭＡ的范围和ＱＴｄ值。结果 （１）ＡＭＩ组早期即存在明显的ＲＷＭＡ,ＲＷＭＡ程度计分明显高于对照组,ＡＭＩ后１周,４周的ＱＴｄ值较对照组显著较长。（２）ＡＭＩ组组ＱＴｄ值随ＲＷＭＡ程度     

老年急性心肌梗死患者窦性心律和室性早博时QT离散度的变化及意义

对100例老年急性心肌梗死（AMI）患者、50例不稳定性心绞痛（UAP）患乾和40例正常人进行QTd检测。发现AMI患者室性早博时QTd(QTd-V)明显高于窦性心律时QTd（QTd-S)(P＜0．001）,且二者呈明显正相关;AMI患者QTd-V和QTd-S明显高于UAP组和对照组（P＜0．001）。提示老年AMI患者QTd-V和QTd-S可能具有同样的临床价值。     

施太可对急性心肌梗死不同时期QT离散度的影响

目的:探讨施太可对急性心肌梗死不同时期QT离散度(QTd)的影响,及其与心脏事件的关系。方法:86例急性心肌梗死患者分为施太可组(40例)和对照组(46例),分别在入院时和入院后1、3、7、21日记录静息12导联同步心电图及Holter,计算QTd并分析其与心脏事件的关系。结果:急性心肌梗死患者QTd于发病24h最高,3日后开始下降,7日降至最低。施太可组QTd在3日后与对照组比显著降低;施太可组心脏事件发生率21.2％显著降低于对照组34.8％(P<0.01);发生心脏事件患者的QTd为(77.19±10.85)ms显著高于无心脏事件者(59.17±9.71)ms(P<0.01)。结论:急性心肌梗死早期存在显著QTd增加,施太可能显著降低急性心肌梗死患者QTd和减少心脏事件的发生。     

QT dispersion and transmural dispersion of repolarization in patients with familial Mediterranean fever

Abstract

Familial Mediterranean fever (FMF) is a disease characterized by sporadic, paroxysmal attacks of fever and serosal inflammation. QT dispersion (QTd) and transmural dispersion of repolarization (TDR), simple noninvasive arrhythmogenic markers, that can be used to assess homogeneity of cardiac repolarization, have not been studied in FMF patients before. The aim of our study was to evaluate the QTd and TDR in FMF patients without overt cardiac involvement. A total of 50 patients with FMF (30 men, 20 women, 29.4 ± 11.8 years) and 50 controls (30 men, 20 women; mean age 31.3 ± 11.9 years) were included. QTd, corrected QTd (cQTd), maximum QT (QTmax), maximum corrected QT (cQTmax), minimum QT (QTmin), and minimum corrected QT intervals (cQTmin) and TDR were measured from standard 12-lead electrocardiography (ECG). We found that QTd, QTmax, and TDR were greater in FMF patients than in the control group (36.0 ± 11.4 vs. 20 ± 11.2, P < 0.001 and 354.8 ± 30.9 vs. 342.8 ± 18.0, P = 0.02; 62.0 ± 16.0 vs. 49.0 ± 9.5 P < 0.001, respectively), as were cQTd and cQTmax (40.4 ± 13.5 vs. 21.9 ± 12.4, P < 0.001 and 397.7 ± 40.2 vs. 375.5 ± 25.4 P = 0.001). A modest positive correlation was found between cQTd and C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) (r = 0.30, P < 0.001; r = 0.40, P < 0.001; respectively). QTd, which is an index of inhomogeneity of ventricular repolarization and an important predictor of cardiovascular mortality, and TDR, which is a better marker of cardiac repolarization, increased in FMF patients similarly as in other rheumatologic diseases.     

Reduction in QT dispersion by sotalol following myocardial infarction

Increased dispersion of ventricular recovery time is believed to be a substrate for serious ventricular arrhythmias. Class III antiarrhythmic drugs probably operate by decreasing dispersion through homogeneous prolongation of recovery time. A single surface QT value gives no information on recovery time dispersion but interlead variation in QT may be relevant. QTc dispersion was measured in 67 patients post myocardial infarction randomized to treatment with either sotalol or placebo. QTc dispersion was calculated as the difference between the maximum and minimum QTc in any surface electrocardiogram lead. Both maximum QTc and QTc dispersion varied considerably following infarction but throughout the 6-month follow-up period maximum QTc was significantly greater (P less than 0.05) and QTc dispersion significantly less (P less than 0.05) in patients on sotalol compared with placebo. These findings are in accord with expected changes in ventricular recovery time and provide strong support for the hypothesis that surface electrocardiogram QT variation reflects regional differences in ventricular recovery time.     

急性心肌梗死患者QT离散度变化与室壁厚度异常的关系

目的　观察急性心肌梗死(AMI)患者QT间期离散度变化与室壁厚度异常的关系。方法　观察35例AMI患者和31例劳力型心绞痛患者QT离散度与室壁收缩厚度改变百分率的变化。结果　(1)AMI后第1天、第4周的QTd值较对照组明显延长。对照组和AMI组区域性收缩厚度改变百分率之间差异有显著性(t=6.77,P<0.01)。(2)AMI后第1天和第4周QTd值与区域性收缩厚度改变百分率呈显著负相关(r=-0.85,r=-0.72,P值均<0.01)。结论　AMI后QTcd显著延长,并与收缩时室壁厚度改变密切相关。     

Value of QT dispersion in evaluating spatial dispersion of ventricular repolarization during acute myocardial ischemia

OBJECTIVES:

To study the value of epicardial QT interval dispersion in predicting ischemia-induced heterogeneity of ventricular repolarization.

ANIMALS AND METHODS:

Ischemia was produced by total occlusion of the obtuse branch of the circumflex coronary artery in seven open-chest sheep. A 64-channel electrocardiogram (ECG) was acquired from the epicardium before and after coronary artery occlusion. Wavelet transformation was used to determine the characteristic points of the epicardial ECGs, and to measure the QT interval and activation-recovery interval (ARI) and their dispersions.

RESULTS:

The average QT interval and ARI from the epicardial ECG were not changed by acute myocardial ischemia (P=0.07 and P=0.13, respectively). QT dispersion remained unchanged during ischemia (P=0.17), whereas ARI dispersion was significantly increased by acute ischemia (59.9±24.0 ms versus 126.3±32.1 ms, P<0.001).

CONCLUSIONS:

These findings indicate that epicardial QT dispersion is less sensitive than ARI dispersion in estimating repolarization heterogeneity induced by acute myocardial ischemia.     

QT离散度对心肌梗死患者预后的临床评价

目的探讨QT离散度(QTd)对陈旧性心肌梗死患者临床预后的价值.方法139例陈旧性心肌梗死(OMI)患者记录静态12导联同步心电图,计算QTd,平均随访(25.2±10.0)个月.结果随访期间共发生临床事件43例,发生率为31%,其中心原性死亡11例,再次心肌梗死10例,严重室性心律失常13例,心力衰竭9例.所有患者按QTd≤70ms和＞70ms分为两组,经Kgplan-Meier曲线分析,QTd＞70ms组临床事件发生率明显高于QTd≤70ms组(P＜0.01).利用COX回归单因素分析显示,以临床事件为终点时,比例风险比(HR)为2.41(P＜0.01),多因素COX回归分析调整年龄、冠状动脉病变支数、左室射血分数(LVEF)等因素后比例风险比(HR)为2.56(P＜0.01).结论QTd在多个潜在的不利于OMI患者的预后因素中,是一个独立预测OMI患者临床事件的因素.     

静脉溶栓治疗对急性心肌梗死患者QT间期离散度及室性心律失常的影响

目的　研究静脉溶栓心肌再灌注治疗对急性心肌梗死 (AMI)患者QT间期离散度(QTd)与校正的QT间期离散度 (QTcd)及室性心律失常 (VA)恶性程度的影响。方法　分别于入院时及溶栓治疗后 4周记录 15例溶栓成功及 17例溶栓未成功患者常规 12导联心电图 ,计算QTd及QTcd ,并行心电监测 ,记录住院期间发生的VA。结果　再通组 (15例 ) 4周后QTd与QTcd[(5 2 .9± 10 .4)ms、(5 8.7± 12 .3 )ms]与溶栓前QTd与QTcd比较 [(69.7± 15 .5 )ms ,(80 .5± 2 7.0 )ms]显著减小 (P <0 .0 5 )。 4周后再通组较溶栓失败冠脉未通组 (17例 )QTd与QTcd[(63 .7±15 .5 )ms ,(72 .3± 2 5 .4)ms]显著减小 (P <0 .0 5 )。再通组VA恶性程度与未通组比较有显著降低 ,死亡率亦降低。结论　早期静脉溶栓成功心肌再灌注治疗可以显著减小心肌梗死患者的QT间期离散度 ,并降低室性心律失常的恶性程度