QT间期离散度与左心室肥厚的关系及依那普利对其影响

目的：探讨ＱＴ间期离散度（ＱＴｄ）与左心室肥厚的关系及依那普利治疗对其的影响。方法：选择高血压病（ＥＨ）患者５７例，其中合并左心室肥厚（ＬＶＨ）者（ＥＨ＋ＬＶＨ组）３０例，无合并左心室肥厚者（ＥＨ－ＬＶＨ组）２７例；正常对照者（正常对照组）２４例。用超声心动图仪检测法求得左心室重量，同时从心电图上测得ＱＴｄ与校正后ＱＴｄ（ＱＴｃｄ）。ＥＨ＋ＬＶＨ组患者用依那普利治疗６个月。结果：①ＥＨ＋ＬＶＨ组患者ＱＴｄ与ＱＴｃｄ明显大于ＥＨ－ＬＶＨ组和正常对照组，而ＥＨ－ＬＶＨ组和正常对照组间无显著性差异；②ＱＴｄ和ＱＴｃｄ与左心室重量呈显著正相关（ｒ＝０．７５，Ｐ＜０．０５及ｒ＝０．６１，Ｐ＜０．０５）；③治疗６个月后，ＱＴｄ和ＱＴｃｄ、左心室重量均降低，且ＱＴｄ缩小程度（ΔＱＴｄ）、ＱＴｃｄ缩小程度（ΔＱＴｃｄ）与左心室重量减轻程度（ΔＬＶＭ）亦呈显著正相关。结论：左心室肥厚是高血压病患者ＱＴｄ增大的主要原因；ＱＴｄ可作为左心室肥厚程度的评估指标；依那普利能有效逆转左心室肥厚，减小ＱＴｄ。     

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。     

老年冠心病患者QT离散度变化及其临床意义

目的探讨老年冠心病患者ＱＴ离散度（ＱＴｄ）和心率校正的ＱＴ离散度（ＱＴｃｄ）与致命性室性心律失常（ＦＶＡ）及心衰（ＨＦ）之间的关系。方法测定了８４例老年冠心病患者的ＱＴｄ及ＱＴｃｄ，其中心原性猝死（ＣＳＤ）９例，ＦＶＡ２３例，非ＦＶＡ６１例。有ＨＦ４７例，无ＨＦ３７例。结果ＣＳＤ组ＱＴｄ、ＱＴｃｄ显著大于ＦＶＡ及非ＦＶＡ组（Ｐ＜０．０５；Ｐ＜０．０１），ＦＶＡ组ＱＴｄ、ＱＴｃｄ大于非ＦＶＡ组（Ｐ＜０．０１），ＨＦ组ＱＴｄ、ＱＴｃｄ显著长于无ＨＦ组（Ｐ＜０．０１）。本文ＱＴｄ和ＱＴｃｄ呈显著正相关（ｒ＝０．９７２０，Ｐ＜０．０１）。结论作者认为ＱＴｄ和（或）ＱＴｃｄ可作为评估老年冠心病患者发生ＦＶＡ和（或）ＨＦ预后的重要参考指标。     

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     

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。     

冠心病患者的心室晚电位、室性早搏与心肌复极离散度的关系

对７０例冠心病患者和２１例健康人的心电图数值进行测量，并对心室晚电位、室性早搏与心电图各测值的关系进行研究。结果：①心绞痛和陈旧性心肌梗塞患者ＱＴｃ、ＱＴｄ、ＪＴ、ＪＴｃ、ＪＴｄ及ＪＴｃｄ明显高于健康对照组（Ｐ＜０．０５或＜０．０１）。陈旧性心肌梗塞组患者ＱＴｃ、ＱＴｄ、ＱＴｃｄ及ＪＴｄ、ＪＴｃｄ高于心绞痛组（Ｐ＜０．０５或＜０．０１）。②心室晚电位阳性的冠心病患者的ＱＴｄ、ＱＴｃｄ、ＪＴｄ、ＪＴｃｄ明显高于心室晚电位阴性的冠心病组（Ｐ＜０．０５或＜０．０１）。③冠心病伴室性早搏者ＱＴｃ、ＱＴｄ、ＱＴｃｄ、ＪＴ、ＪＴｃ、ＪＴｄ、ＪＴｃｄ明显增加（Ｐ＜０．０５或＜０．０１）。提示冠心病存在明显心肌复极不均匀，心室晚电位和室性早搏与心肌复极离散度有关。     

运动负荷前后QTc,QTd,QTcd动态变化

运动负荷前后ＱＴｃ，ＱＴｄ，ＱＴｃｄ动态变化宋成运严亦夏张秩林张淑文张清华（解放军３０５医院心内科北京１０００１７）关键词ＱＴｃ间期ＱＴ离散度运动试验近年来，ＱＴｃ（用心率校正的ＱＴ间期）延长及ＱＴ离散度（ＱＴｄ）增大的临床意义愈益受到重视［１，２］...     

老年心肌缺血者QTc和QTcd变化及临床意义

测定了６４例老年心肌缺血（ＭＩＳ）患者和２１例心肌梗塞（ＭＩ）患者心电图的ＱＴｃ间期和ＱＴｃ离散度（ＱＴｃｄ），并与心血管神经官能症（ＣＶＮ）及正常老年人进行比较；探讨ＱＴｃ、ＱＴｃｄ与致命性室性心律失常（ＦＶＡ）、心原性猝死（ＣＳＤ）的关系；分析ＭＩ不同部位的ＱＴｃｄ变化以及稳定性心绞痛（ＳＡＰ）和不稳定性心绞痛（ＵＳＡＰ）的ＱＴｃｄ差异。结果：老年女性患者ＱＴｃ较男性长（Ｐ＜０．０５），而ＱＴｃｄ两者无差异；老年ＭＩＳ患者ＱＴｃ和ＱＴｃｄ较正常组明显延长（Ｐ＜０．０１）；ＭＩ前壁、下壁和后壁３组ＱＴｃｄ无明显差异（Ｐ＞０．０５）；ＵＳＡＰ患者ＱＴｃｄ较ＳＡＰ长（Ｐ＜０．０５）。     

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。     

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。     

冠状动脉血管成形术对QT离散度的影响及其意义

为阐明冠状动脉血管成形术（CA）对QT离散度（QTd）的影响，并探讨其意义。我们分析48例（心绞痛14例，心肌梗塞34例）CA术前后1天内所记录的心电图，测算QT、QTd、心率校正QT间期（QTc）和心率校正QT离散度（QTcd）。病例分为：心绞痛CA成功组、心肌梗塞CA成功组和CA失败组，分别对3组的4项指标作术前与术后比较。结论：前两组本前与本后QT和QTc差异均无显著性，但术后QTd和QTcd较术前显著减小（分别为38±13vs65±15ms，1．2±0．5vs2．4±0．8；38±16vs66±25ms，1．3±0．6vs2．1±0．9，P均＜0．001）。CA失败组术前后4项指标差异均无显著性。结论：成功的CA能显著减小心绞痛和心肌梗塞患者的QTd，提示可能改善患者的预后；术后QTd减小可能反映了顿抑或冬眠心肌的“苏醒”，并表明梗塞区尚有存活心肌。     

QT interval dispersion pattern in patients with acute ischemic stroke: Does the site of infarction matter?

BACKGROUND:

QT interval dispersion (QTD) is an independent predictor of outcome following acute neurological events.

OBJECTIVES:

To explore QTD patterns and their relation to the affected cerebral region in patients with acute ischemic stroke.

METHODS:

Thirty patients with first acute ischemic stroke (the first stroke the patients had ever experienced) (study group) and 30 healthy controls (control group) were enrolled. Patients underwent magnetic resonance imaging to confirm and localize cerebral damage. Patients in the study group were further subdivided according to the site of infarction into four subgroups – namely, cortical, subcortical, brain stem and cerebellar infarctions, as well as according to insular involvement. All included subjects underwent 12-lead electrocardiography to measure QTD and corrected QT dispersion (QTcD).

RESULTS:

In the study group, both QTD and QTcD on the first hospitalization day were significantly higher than in the control group (P<0.05 for both). Similarly, in the study group, both QTD and QTcD values on the first hospitalization day were significantly higher than the respective values on the third day (P<0.001 for both). No significant differences were found among the four territorial subgroups, or between right- and left-sided subgroups, regarding QT interval measurements, whether on the first or third day (P>0.05 for all). However, ‘first-day’ QTD and QTcD of patients with insular involvement were significantly higher than in those without such involvement (P<0.001 for both).

CONCLUSIONS:

Both QTD and QTcD increased significantly in patients with acute ischemic stroke during the first hospitalization day. This increase of ‘first-day’ QTD and QTcD was significantly higher in patients with insular involvement than in those without such involvement.     

QT Dispersion in Healthy Chinese Children and Adolescents

Background: QT dispersion (QT_d) reflects the interlead difference in QT interval. It may provide a measure of repolarization inhomogeneity. Studies on QT_d mainly involve adults, while QT_d in children are less well studied. The aim of this study was to evaluate QT_d in healthy children and assess the relationship of gender, age, and anthropometric parameters, viz. weight (W), height (H), body mass index (BMI), and body surface area (BSA) to QT_d. Methods: Five hundred and one Chinese children and adolescents (243 boys, 258 girls) with no history of cardiovascular diseases were studied. Their ages ranged from 6.3 to 17.5 years. Surface 12-lead electrocardiograms were measured in each child at rest. QT and R-R intervals in each of the 12 leads were manually measured at a magnification of 2X. QT was corrected to QT_c according to Bazett's formula. QT_d was calculated as the difference between the maximum and minimum QT of the measured leads, while corrected QT_d (QT_cd) was the difference between the maximum and minimum QT_c of the measured leads. Adjusted QT_d was QT_cd divided by the square root of the number of measurable leads. Results: Mean QT_d of all subjects was 34 ms (95% Cl 33.6–35.1 msl. Mean QT_d for boys and girls was 35 ms and 34 ms, respectively (P = 0.18). Mean QT_cd for the whole group was 47 ms (95% Ci 45.8–48.2 ms), while mean adjusted QT_cd was 14 ms (95% Cl 13.8–14.5 ms). There were no significant gender differences in QT_cd or adjusted QT_cd. Weak negative correlation existed between age and QT_d, QT_d and adjusted QT_cd (r =?0.22, r =?0.26, r =?0.21, respectively, P < 0.001 Similarly, QT_cd also had a weak significant negative correlation with W (r =?0.20), H (r =?0.21) and BSA (r =?0.22), P < 0.001. However, multiple stepwise regression analysis revealed that only age was significantly related to QT_cd (R2 = 0.066) and QT_d (R2 = 0.059), P < 0.001. Conclusions: The results of this study indicate a trend of decreasing QT_d and QT_cd with increasing age, supported by multiple regression analysis. However indices of QT_d in children are not influenced by anthropometry. This information may be useful for the clinical application of QT_d in children. A.N.E. 1999;4(3):281–285     

正常成人QTmax,QTmin在十二导心电图的分布规律及临床意义

目的 找出正常成人最大ＱＴ间期（ＱＴｍａｘ）和最小ＱＴ间期（ＱＴｍｉｎ）在十二导心电图的分布规律,提高ＱＴ离散度的敏感性。方法 在５８２例正常成人进行十二导心电图同步记录检查,找出ＱＴｍａｘ和ＱＴｍｉｎ在各导联的数量和在十二导心电图中的分布规律,统计各导联缺失和不同导联组合缺失时的ＱＴ离散度均值,观察其对ＱＴｄ的影响。结果 ５８２例心电图平均ＱＴｄ３５．３±９．５ｍｓ,各导联ＱＴ间期均值ａｖＬ最小     

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     

Reproducibility of Minimum,Maximum and Median QT Intervals in the 12‐Lead Resting ECG

Background: Heterogeneity in the recovery of ventricular refractory periods is an important factor in the development of ventricular arrhythmia. The QT dispersion (QTD) is increasingly used to measure this heterogeneity but its clinical value is limited due to methodological problems. QTD is defined as the maximum minus the minimum QT intervals that are suspected to be the least reproducible of the QT measurements. Objective: To analyze the reproducibility of the minimum, maximum and median QT intervals. Material: One database consisted of 356 subjects: 169 with diabetes and 187 nondiabetic control persons. The other database consisted of 110 subjects with remote myocardial infarction: 55 with no history of arrhythmia, and 55 with a recent history of ventricular tachycardia or fibrillation. Methods: 12‐lead surface ECGs were recorded with an amplification of 10 millimeters per millivolt at a paper speed of 50 mm/s. QT was measured manually by the tangent‐method. The reproducibility was calculated from measurements of QT in successive beats. Results: The standard deviation (SD) of QTs reproducibility was 9 ms for the arrhythmia data and 8 ms for the diabetes data. The reproducibility of QT_max and QT_min were on average 30% and 15% worse than for QT_median. The SD of QT_max was significantly higher than for QT_median in both database (P < 0.001), whereas SD of QT_min was only significantly higher than for QT_median for the diabetes data (P < 0.001). Conclusions: The reproducibility of QT_min and in particular QTmax was significantly lower than for QT_median. This indicates that the QT dispersion is based on the least reproducible of the QT measurements. A.N.E. 2000;5(4):354–357     

T-peak to T-end interval may be a better predictor of high-risk patients with hypertrophic cardiomyopathy associated with a cardiac troponin I mutation than QT dispersion

BACKGROUND: Patients with hypertrophic cardiomyopathy (HCM) associated with a deletion of lysine 183 (K183del) in the cardiac troponin I (cTnI) gene suffer sudden cardiac death at all ages. However, the correlation between QT variables and sudden cardiac death in these patients remains uncertain. HYPOTHESIS: We evaluated the correlation between QT variables and sudden cardiac death and/or ventricular tachyarrhythmia (SCD/VT) in patients with HCM associated with the cTnI mutation. METHODS: We analyzed 10 probands with HCM associated with the cTnI gene K183del and their family members. The subjects were divided into three groups: Group A (n = 7), mutation carriers with SCD/VT; Group B (n = 16), mutation carriers without SCD/VT; Group C (n = 24), no mutation carriers. QT intervals were corrected using Bazett's formula. RESULTS: Maximum QTc and corrected QT dispersion were significantly longer in Groups A and B than in Group C. However, there were no differences in either parameter between Groups A and B. On the contrary, the peak-to-end interval of T wave/QT interval in V5 (Tpe) in Group A was significantly longer than that in Groups B and C. Logistic regression analysis revealed that Tpe was a good clinical predictor for SCD/VT in patients with HCM in this study. CONCLUSIONS: These results suggest that Tpe rather than QT dispersion may be one of the best predictors for SCD/VT in patients with HCM associated with the K183del mutation in the cTnI gene.