急性心肌梗死QT离散度和JT离散度与心功能的相关性

作者测定分析１００例急性心肌梗死ＡＭＩ）患者住院第３ｄ的１７导联心电图ＱＴ间期离散度及ＪＴ间期离散度，并以１００例正常人作对照。结果表明：ＡＭＩ组的ＱＴｄ及ＪＴｄ较正常组明显增大，差异非常显著。ＡＭＩ泵功能级别与ＱＴｄ及ＪＴｄ叶正相关，即泵功能级别愈高，则ＱＴｄ，ＪＴｄ值愈大。     

急性心肌梗塞早期QT间期离散度、JT间期离散度增加与近期预后的关系

测定１０７例急性心肌梗塞（ＡＭＩ）患者第三心肌梗塞日的ＱＴ间期离散度（ＱＴｄ）和ＪＴ间期离散度（ＪＴｄ）．并以１００例正常人作对照。结果显示：ＡＭＩ组ＱＴｄ、ＪＴｄ较对照组显著增大（均Ｐ＜０．００１）。住院期间死亡组（３Ｏ例）ＱＴｄ与ＪＴｄ较存活组（７７例）明显增大（均Ｐ＜０．００１）。提示以ＱＴｄ、ＪＴｄ增大来评价ＡＭＩ患者的近期预后有一定意义。     

老年急性心肌梗塞QT离散度变化及临床意义

目的探讨老年急性心肌梗塞（ＡＭＩ）早期心电图ＱＴ离散度（ＱＴｄ）变化特点，ＱＴｄ与临床表现的关系，以及ＱＴｄ对预后的意义。方法测量老年ＡＭＩ组和非老年ＡＭＩ组各５０例及老年无心脏病组５４例１２导联心电图ＱＴｄ（ＪＴｄ），即ＱＴ间期（ＪＴ）最大值与最小值之差，计算出ＱＴｃｄ（ＪＴｃｄ）。结果老年ＡＭＩ组ＱＴｄ（ＪＴｄ）与其他２组分别有非常显著性差异（Ｐ＜０．００５～０．００１）。两ＡＭＩ组死亡与生存者ＱＴｄ（ＪＴｄ）均有显著、非常显著性差异（Ｐ＜０．０５～０．０１）。老年ＡＭＩ组重度泵衰竭、室性心律失常发生率及死亡率高于非老年ＡＭＩ组。结论ＱＴｄ（ＪＴｄ）可作为判断ＡＭＩ患者病情与预后的一项有价值的指标，对老年ＡＭＩ患者更具有临床意义。     

急性心肌梗塞QT离散度增加与室颤的关系

对急性心肌梗塞（ＡＭＩ）患者６２例发病４８小时内首次心电图（ＥＣＧ）的ＱＴ间期离散度（ＱＴｄ）进行了测定。结果：ＡＭＩ早期原发性室颤患者ＱＴｂ及ＪＴｄ显著高于非室颤组（ＱＴｄ１０７．５０±３５．８０ｍｓ，４８．９０±１７．９０ｍｓ，Ｐ＜０．０１。ＪＴｄ１０７．５０±３１．００ｍｓ，５２．６０±１９０．００ｍｓ，Ｐ＜０．０１）。提示：ＱＴｄ或ＪＴｄ增大，室颤发生可能性增大。认为：ＱＴｄ和（或）ＪＴｄ     

急性心肌梗塞患者溶栓治疗对QT离散度和JT离散度的影响

观察４８例急性心肌梗塞（ＡＭＩ）患者静脉溶栓治疗前后ＱＴ离散度（ＱＴｄ）、ＪＴ离散度（ＪＴｄ）的变化，结果显示，溶栓成功组ＱＴｄ、ＪＴｄ较溶栓前显著减少而非成功级ＱＴｄ、ＪＴｄ较溶栓前无显著性差异，因此，ＱＴｄ、ＪＴｄ可作为判断溶栓成功的参数指标之一。     

老年人急性心肌梗死QT离散度变化的临床意义

目的 观察老年急性心肌梗死（ＡＭＩ）患者溶栓前后ＱＴ离散度（ＱＴｄ）的变化，分析其与室性心律失常的关系。方法 测量４０例老年ＡＭＩ患者的ＱＴ间期，计算其ＱＴｄ及校正后的ＱＴ离散度（ＱＴｄ）。结果 （１）ＡＭＩ组ＱＴｄ及ＱＴｄｃ大于１００ｍｓ患者中，室性心动过速（室速）、心室颤动（室颤）发生率明显高于ＱＴｄ、ＱＴｄｃ小于１００ｍｓ者（７３．０％及６．８％，Ｐ〈０．００１）。（２）溶栓再通组溶栓后ＱＴ     

QT间期离散度在扩张型心肌病严重心功能不全患者预后中的意义

目的：探讨ＱＴ间期离散度（ＱＴｄ）和（或）ＪＴ间期离散度（ＪＴｄ）的增加与扩张型心肌病严重心功能不全患者远期预后的关系。方法：测定２６例扩张型心肌病（ＮＹＨＡＩＩ～ＩＶ级）患者与２０例健康者体表１２导联心电图的ＱＴｄ及ＪＴｄ。并对全部患者随访１６～３８个月。结果：２６例扩张型心肌病患者心性死亡１７例（６５．４％）。死亡组ＱＴｄ及ＪＴｄ分别为７８．７±４２．４和８０．７±３８．６ｍｓ，明显高于存活组（４７．８±２０．６和５０．２±１６．１ｍｓ）和正常对照组（３９．６±１２．２和４２．５±１５．１ｍｓ），差异有显著性（Ｐ均＜０．０５）。ＱＴｄ＜６０ｍｓ、６０ｍｓ＜ＱＴｄ＜１００ｍｓ和ＱＴｄ＞１００ｍｓ的死亡率分别为３３．３％，７５．０％和１００％，差异显著（Ｐ＜０．０５），猝死率分别为０％、１６．７％和１００％，差异非常显著（Ｐ＜０．００１）。结论：ＱＴｄ明显增加的患者远期死亡率显著高于ＱＴｄ正常或轻度增加的患者，并可能与猝死发生有关。提示ＱＴｄ（或ＪＴｄ）可作为判断预后的独立参数。     

QT,JT离散度对扩张型心肌病患者猝死的预测价值

测定了３１例扩张型心肌病患者（下称患者组）与２０例健康者（下称对照组）体表１２导联心电图的ＱＴ离散度（ＱＴｄ）和ＪＴ离散度（ＪＴｄ），并随访１２￣２０个月。结果显示，猝死心肌病患者（１１例）的ＱＴｄ、ＪＴｄ明显高于心衰死亡者、存活者及对照组（Ｐ均〈０．０１）。因心衰死亡者的ＱＴｄ、ＪＴｄ明显高于对照组（Ｐ均〈０．０１），与存活患者无明显差异（Ｐ均〉０．０５）。ＪＴｄ〈６０ｍｓ、６０ｍｓ〈ＪＴｄ〈１     

急性心梗QT间期离散度增加与室性心律失常的关系

急性心梗ＱＴ间期离散度增加与室性心律失常的关系夏琼常州戚墅堰铁路医院（２１３０１１）心电图不同导联间的ＱＴ间期存在差异，ＱＴ间期离散度（ＱＴｄ）是这些差异的量度，它代表节段性心肌复极差异。本文观察分析了急性心肌梗塞（ＡＭＩ）患者的ＱＴｄ及ＪＴ间期离散...     

QT及JT离散度对心性猝死预测价值的探讨

测定３２例心性猝死和３０例非猝死性心性死亡病人入院后的首次心电图ＱＴ离散度（ＱＴｄ）和ＪＴ离散度（ＪＴｄ），产以３０例存活病人作对照，结果显示：（１）心性猝死组ＱＴｄ，ＪＴｄ较存活组和非猝死性心性死亡组显著增大（前者Ｐ均〈０．０１，后者Ｐ均〈０．０５，而非猝死性心性死亡组与存活组ＱＴｄ，ＪＴｄ比较差异均无统计学意义。（２）在心性猝死病人中，死亡直接原因为快速室性心律失常组（２３例）的ＱＴｄ，ＪＴｄ     

急性心肌梗死Q—T离散度,J—T离散度的演变

为了解急性心肌梗死患者的Q-T_d、J-T_d动态变化,观察105例急性心肌梗死患者发病后第1—7天、第14、21及28天心电图的Q-T_d和J-T_d。结果显示:Q-T_d、J-T_d以发病后第2天(65.18±34.08,59.24±32.18ms)及第3天(63.18±28.51;60.57±26.82ms)为最大。提示急性心肌梗死后第2—3天Q-T_d、J-T_d达峰值,可作为预测病情的参考指标。     

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.     

急性心肌梗死Q—T及J—T离散度与室性心律失常的关系

为评价Q-T_d、J-T_d对急性心肌梗死患者发生恶性心律失常的预测价值,观察82例急性心肌梗死患者恶性室性心律失常与Q-T_d、J-T_d的关系。结果显示Q-T_d、J-T_d在恶性室性心律失常组分别为99.47±20.13ms、97.89±21.75ms;潜在恶性室性心律失常组为67.39±14.21ms、61.74±15.57ms;无室性心律失常组为48.75±29.93ms、43.25±22.46ms。3组间差异极为显著(P<0.01),Q-T_d(J-T_d)≥100ms者全部发生恶性室性心律失常。认为Q-T_d(J-T_d)值越大,室性心律失常的发生率越高;梗死早期Q-T_d(J-T_d)值增大>60ms可作为预测恶性室性心律失常发生的一项敏感指标。     

长期运动诱导的心肌肥厚对QT离散度的影响

目的对长期运动左心室重量增加个体的QT离散度(QTd)进行分析。方法各入选26例长期运动个体和运动较少的正常个体,经二维超声心动图测量心室结构参数,记录同步12导联心电图测量QT离散度。结果长期运动的个体左心室重量明显大于运动少的个体(216±39kg对155±30kg;P<0.01);长期运动个体校正的QT离散度(QTcd)比运动少的个体明显减少(42±13ms对51±15ms,p<0.01)。左心室重量(LVM)与QT离散度和QTcd呈明显的负相关(r=-0.38,p=0.002和r=0.53,p=0.001)。结论运动诱导的心肌肥厚使QT离散度减小,反映了长期运动个体心肌复极化的稳定性。     

QT dispersion failed to estimate the global dispersion of ventricular repolarization measured using monophasic action potential mapping technique in swine and patients

The aim of this study was to evaluate whether the QT dispersion measured from 12-lead electrocardiogram (ECG) can estimate the global dispersion of ventricular repolarization (DVR) measured using a monophasic action potential (MAP) mapping technique. Monophasic action potentials were recorded from 75 +/- 12 left ventricular sites in 10 pigs and from 48 +/- 16 left or right ventricular sites in 15 patients using the CARTO mapping system. The maximum DVRs in both end-of-repolarization and MAP duration among all the mapped sites were calculated and termed as global DVR for each measurement. QT intervals, QT peak and QT end , were measured from the 12-lead ECG, and QT dispersions; namely the differences between the maximum and the minimum of the QT peak and QT end were calculated. We found that QT dispersions were significantly smaller than (P < .05) and poorly correlated with the global DVRs both in pigs and patients. Bland-Altman agreement analysis demonstrated a marked variation of the differences and an obvious lack of agreement between the results obtained using the ECG and the MAP methods. In our patients, the global DVR increased markedly during ventricular tachycardia as compared with that during sinus rhythm (P < .05), whereas there was no significant difference in QT dispersion between these 2 subgroups. In conclusion, QT dispersion on the surface ECG could not estimate the global DVR measured using the MAP mapping technique. These findings are not consistent with some previously reported observations, suggesting the need for reappraisal of the electrophysiological implications of QT dispersion.     

心率对QT离散度的影响

目的 探讨心率对QT离散度（QTd)的影响以及心率对QTd进行校正的必要性。方法 采用食道心房调搏法改变心率,同时记录每种心率的12导联同步心电图以计算相应的QTd,采用Bazett公式对QTd进行校正（QTcd)。结果 QTd、QTcd均与心率呈负相关（r分别为－0．544和－0．664,P均小于0．001）;QTd与QTcd呈显著正相关（r＝0．98,P＜0．001）。结论 QTd、QTcd与心率呈负相关,QTd与QTcd呈高度正相关,故不必用Bazett公正校正QT间期。     

Q—T离散度增加与急性高原病的关系

为了解急性高原病患者的Q-T离散度(Q-T_d)改变,观察60例健康青年急进高原与急性高原病及重症高原反应的关系。结果急性高原病和重症高原反应组与未发病组Q-T_d分别为76.42±11.27ms,46.41±10.04ms;其J-T_d分别为60.42±14.72ms,37.28±9.76ms,两组差异有显著意义(P<0.01)。认为Q-T_d及J-T_d增加与急性高原病的发生有密切关系。     

QT-interval dispersion in malnourished children

Background: Little is known about the electrocardiographic (ECG) QT interval and its variability in malnourished children. Hypothesis: The study of the QT interval and its dispersion in malnourished children was undertaken to determine whether the QT interval and its variability are increased in these children. Methods: In 40 children (20 malnourished and 20 controls) aged 12.2 ± 14.4 months (23 male) a conventional ECG was performed for computing heart rate, heart rate variability, corrected QT interval, and QT-interval dispersion. A blood sample was obtained for measuring hemoblogin, hematocrit, plasma protein, and plasma electrolytic concentrations. Results: Corrected heart rate, heart rate variability, and QT interval were similar in both groups. When compared with the control group, the malnourished children had greater corrected QT-interval dispersion, and that dispersion was more accentuated in the precordial leads. They also had repolarization abnormalities (flattened or inverted T waves and U waves). Hemoglobin, hematocrit, plasma protein, and plasma electrolytic concentrations were lower in the malnourished children. However, the ECG findings showed no statistically significant relationship with either the blood parameters, the severity or type of malnutrition, and the size or the weight of the children. Conclusions: QT-interval dispersion is increased in malnourished children and the dispersion is more accentuated in the precordial leads.