QT间期及其离散度与冠状动脉病变的关系

探讨心电图QT间期、QT离散度 (QTd)与冠状动脉病变及其程度和范围的关系。分析 138例行选择性冠状动脉造影病例的临床及心电图资料 ,观察不同程度和范围的冠状动脉病变对QT指标的影响。结果 :无冠状动脉狭窄病人的QTd为 42 .0± 18.2 4ms,单支病变组及多支病变组的QTd分别为 48.42± 17.11,5 9.15± 2 2 .75ms ,P均 <0 .0 5 ;轻度狭窄组及重度狭窄组的QTd分别为 48.6 7± 2 0 .45 ,5 8.12± 2 1.6 1ms ,P均 <0 .0 5。结论 :QTd延长有助于心肌缺血的诊断 ,并可能反映冠状动脉病变的范围及程度     

冠心病冠状动脉病变程度对QT离散度的影响

我们将经过冠状动脉造影 (ＣＡＧ)确诊为冠心病的患者 ,按其冠脉病变支数分成三组 ,分别测量每组的ＱＴ离散度 (ＱＴｄ)和较正ＱＴ离散度 (ＱＴｃｄ) ,以期探讨冠心病冠脉病变程度对ＱＴｄ和ＱＴｃｄ的影响。研究对象与方法一、研究对象 :70例患者均行冠状动脉造影术 ,并全部符合以下标准 :1 有 1支及 1支以上主要冠状动脉 (左主干 ,左前降支 ,左回旋支和右冠脉 )或其主要分支 (对角支、边缘支和后降支等 )狭窄≥ 5 0 % ;2 无束支传导阻滞 ;3 无急性心肌梗死 ;4 无严重心功能不全和明显心脏扩大 ;5 入院前未用抗心律失常药物或停用超过 3…     

老年冠心病患者QT间期离散度与冠状动脉病变的关系

老年冠心病患者ＱＴ间期离散度与冠状动脉病变的关系苏勇李源张珊红龚卫琴郑昌柱一、对象和方法对象：选择１９９４～１９９５年间入院行冠状动脉（以下简称冠脉）造影的老年病例１１６例，入选病例均无电解质紊乱、心律失常以及服用影响心肌复极药物史。根据冠脉造影结果...     

QT离散度与冠状动脉病变血管范围关系的探讨

目的 :探讨冠心病患者冠状动脉血管 (冠脉 )病变范围与QT离散度 (QTd)之间的关系。方法 :5 2例经选择性冠脉造影患者常规同步 12导联心电图QTd及QTcd进行观察。结果 :显示有冠脉狭窄的 38例患者 ,其QTd及QTcd均比无冠状动脉狭窄者大 (P <0 0 5 ) ,而单支与双支血管病变患者之间无差异 ,3支以上血管病变患者比单支及双支血管病变患者的QTd及QTcd明显延长 (P <0 0 5 )。结论 :在冠心病患者中 ,QTd及QTcd与冠脉血管狭窄累及的血管数有关 ,心肌缺血及损伤程度越重 ,其QTd及QTcd延长越明显 ,而冠脉血管狭窄程度与QTd及QTcd无相关 ,QTd及QTcd是评价冠心病患者心肌缺血及损伤的一个有意义的指标。     

冠心病心绞痛QT离散度变化的意义

目的:探讨冠心病心绞痛患者QTd变化的临床意义。方法:冠心病心绞痛患者6 2 (男5 0 ,女12 )例,平均年龄6 0 (40～74 )岁,符合1978年WHO制定的标准,且排除电解质紊乱、抗心律失常药物及室内传导阻滞等因素影响。对照组为同期住院无心脏病且心电图正常者5 0 (男4 0 ,女10 )例,平均     

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。     

冠心病室性早搏Lown‘s分级与QT离散度的关系

目的探讨冠心病患者ＱＴ离散度（ＱＴｄ）与其室性早搏Ｌｏｗｎ＇ｓ分级的关系。方法前瞻性、顺序地观察了６０例冠心病患者动态心电图室性早搏Ｌｏｗｎ＇ｓ级别与同日测量ＱＴｄ及相关指标的变化。结果室早Ｌｏｗｎ＇ｓ４～５级冠心病患者ＱＴｄ、ＱＴｃｄ、ＱＴｍａｘ显著大于０级和１～３级患者（分别１０１±３９．４ｖｓ６２±２２．９、６０±２３．４,１１５±５３．７ｖｓ６８±２５．９、７０±２１．６和４６３±５７．８ｖｓ４３０±４１．４、４２２±２９．３均Ｐ＜０．０５）,而ＱＴｍｉｎ无显著改变（Ｐ＞０．０５）。而室早Ｌｏｗｎ＇ｓ０级与１～３级患者比较则ＱＴｄ及相关指标均无显著差异（Ｐ＞０．０５）。结论室早Ｌｏｗｎ＇ｓ４～５级冠心病患者ＱＴｄ显著增大,预示其发生室性折返性心动过速的危险性增高     

冠状动脉病变严重程度、病变位置及介入治疗对QT离散度的影响

总结 15 9例冠状动脉 (简称冠脉 )造影且心电图及临床资料完整的病例 ,为探讨冠脉病变严重程度、病变位置及冠心病介入治疗对QT离散度 (QTd)及校正QT离散度 (QTcd)的影响。结果 :冠脉狭窄≥ 70 %对QTd及QTcd影响明显 (P <0 .0 5 )而冠脉狭窄 <70 %对QTd及QTcd无明显影响 ;冠脉病变所处位置对QTd及QTcd无明显影响 ;介入治疗后QTd及QTcd明显变小 ,P <0 .0 5。结论 :冠脉病变所处位置对QTd及QTcd无明显影响 ,病变严重程度及介入治疗对QTd及QTcd有明显影响。     

经皮冠状动脉腔内成形术对冠心病患者QT离散度的影响

目的:评价经皮腔内冠状动脉成形术(PTCA)对冠心病患者QT离散度的影响。方法:对60例成功行PTCA 及PTCA+支架术的冠心病患者.于术前1 d、术后1～7 d每日定时测定心电图。结果:两组患者PTCA术前QTd及QTcd值均显著高于正常值.PTCA术后各天与术前第1 d比较,均有显著降低(P<0.01)。QTd及QTcd值在术后第1～3 d,较术前有所降低.但仍显著高于正常值水平,至术后第5 d基本降至正常值水平。结论:提示PTCA可降低心绞痛及心肌梗死患者异常的QTd及QTcd值,于术后第5 d接近正常值水平。     

冠心病患者经皮腔内冠状动脉成形术前后QT离散度的对比观察

前瞻性的研究成功的ＰＴＣＡ术对ＣＡＤ患者ＱＴｄ的影响及其临床意义。一、资料及方法 :ＣＡＤ患者均为我院 1998年 10月至 1999年 5月的住院病人 ,年龄、性别、职业及民族不限。包括亚急性ＭＩ、ＯＭＩ、稳定性心绞痛和不稳定性心绞痛患者 ,经选择性冠状动脉造影证实符合ＰＴＣＡ+ 支架植入术 ,ＥＣＧ为窦性心律者。方法 :用标准的方法和设备进行选择性冠状动脉造影和ＰＴＣＡ+ 支架植入术。观察指标 :由专人负责操作同步十二导联电生理记录仪 ,分别记录ＰＴＣＡ+ 支架植入术前半小时至 1小时 ,术后即刻 ,第一天、第三天、第五天和第七天…     

QT离散度与冠状动脉狭窄程度的关系

测量１００例（男８６例，女１４例，平均年龄５６．１±５．６岁）冠状动脉造影者的体表心电图ＱＴ离散度（ＱＴｄ），结果显示:冠状动脉狭窄组ＱＴｄ较冠脉正常组明显延长（Ｐ＜０．０１）。在狭窄程度大于或等于７５％组和狭窄小于７５％组间，ＱＴｄ差异显著（Ｐ＜０．０５），说明ＱＴｄ与冠脉狭窄程度有关（Ｐ＜０．０１）。本文讨论了单支冠脉病变、多支冠脉病变及左室射血分数（ＬＶＥＦ）与ＱＴｄ的关系，其中单支病变和多支病变的ＱＴｄ无明显差异（Ｐ＞０．０５），而ＬＶＥＦ＞４０％和ＬＶＥＦ≤４０％两组间，ＱＴｄ差异非常显著（Ｐ＜０．０１），表明ＱＴｄ与左室射血功能有关     

QT离散度与冠心病猝死

目的 :探讨 QTd对猝死的预测价值。方法 :分析 2 3例发生猝死的冠心病患者和 34例住院冠心病患者的 QT离散度及心率校正 QT离散度。结果 :猝死组 QTd明显高于对照组 ,P<0 .0 5。结论 :QT离散度增大有预测猝死的价值     

心绞痛患者QT离散度与经皮腔内冠状动脉成形术的关系

目的 :探讨经皮腔内冠状动脉成形术 ( PTCA)对心绞痛患者 QT及 JT离散度 ( QTd及 JTd)的作用。方法 :测定 5 0例心绞痛患者 (心绞痛组 ) PTCA术前和术后的 QTd及 JTd,并以 5 0例正常冠状动脉者作对照 (对照组 )。结果 :1心绞痛组于 PTCA后 QTd及 JTd显著减小 ( P <0 .0 1) ,而对照组于冠状动脉造影术后 QTd及JTd与术前比较 ,无明显改变。 2与对照组比较 ,心绞痛组 PTCA前 QTd及 JTd明显增大 ( P <0 .0 1)。术后心绞痛组 QTd及 JTd值虽高于对照组 ,但无统计学意义 ( P >0 .0 5 )。结论 :PTCA能使 QTd及 JTd减小     

心肌梗死患者PTCA术后QTd变化与存活心肌的关系

目的探讨心肌梗死患者经皮冠动脉腔内成形术（PTCA）后QT离散度（QTd）变化与存活心肌的关系。方法48例成功行PTCA的急性和陈旧性心肌梗死患者,分别于手术前后行心电图检查以观察QTd变化,行心血池检查以观察心肌收缩功能改善情况,行心肌代谢和心肌灌注显像以观察心肌存活情况。结果存活心肌阳性组术后QTd明显小于术前（P〈0．01）,心脏收缩功能改善组术后QTd明显小于术前（P〈0．01）。结论成功PTCA术后QTd减小表明梗死部位有存活心肌,QTd可以预测PTCA术后冬眠心肌及心脏收缩功能的恢复程度。     

QT dispersion increases during intubation in patients with coronary artery disease

Anesthetic drugs have been shown to increase QT interval, however data regarding their effects on QT dispersion (QTd) are scarce, especially in patients with coronary artery disease (CAD). We tested whether induction of Anesthesia with thiopental and etomidate would increase QTd in patients with CAD. Thirty American Society of Anesthesiologists (ASA) physical status I-II patients without CAD were randomly allocated to groups I (n = 15) and II (n = 15) and 30 ASA physical status III patients with CAD were randomly allocated to groups III (n = 15) and IV (n=15). Anesthesia was induced with thiopental 5-7 mg/kg IV in groups I and III and with etomidate 0.2-0.3 mg/kg IV in groups II and IV. Endotracheal intubation was facilitated with vecuronium bromide 0.1 mg/kg IV. Twelve-lead electrocardiogram (ECG) was recorded in all patients at baseline (ECG₁), 1 min after the induction agent (ECG₂), 1 min (ECG₃) and 5 min (ECG₄) after intubation. Anesthesia was maintained with isoflurane and nitrous oxide in 34 % oxygen after ECG₂ recording. QTd and corrected QT dispersion (QTcd) were calculated. In patients with CAD induced with thiopental, QT dispersion increased significantly during the intubation period compared with baseline (from 43.0 ± 25.6 ms to 69.2 ± 25.3 ms ; P < .01). Likewise, QT dispersion also increased during intubation in patients with CAD induced with etomidate (from 41.5 ± 17.2 ms to 80.0 ± 33.6 ms; P < .001). There was no increase in QT dispersion in patients without known CAD. QT dispersion seems to be increased during the intubation period in patients with CAD regardless of the induction agents used.     

Impact of coronary collateral circulation on QT dispersion in patients with coronary artery disease

OBJECTIVE: The aim of this study was to assess the effect of coronary collateral circulation (CCC) on QT dispersion (QTD) in coronary artery disease. BACKGROUND: A prolonged QTD has been linked to increased heterogeneity of ventricular repolarization implicated in the genesis of ventricular arrhythmias and has been associated with an adverse prognosis in patients with coronary artery disease. METHOD: CCC and corrected QTD (QTcD) were established in patients who had at least 85% stenosis in the left anterior descending coronary artery or in proximal part or in the body of the right coronary artery. Furthermore, left ventricular function score was determined for all the patients. RESULTS: While CCC was not present (CCC grade 0) in 32 patients, 68 patients were observed with CCC (CCC grade > or =1). Mean QTcD was higher in patients who had CCC grade > or =1 than in patients with grade 0 (64.3+/-3.5 and 46.8+/-2.7, respectively, P=0.002). We detected a significant correlation between the collateral score and QTcD (r=0.354, P=0.001). CCC grade > or =1 patients had higher mean left ventricular function scores than grade 0 patients (P=0.048). Left ventricular function score and QTcD were observed to be correlated (r=0.200, P=0.046). CONCLUSION: CCC in chronic coronary artery disease was not established to have a positive decreasing effect on QTcD. On the contrary, QTcD values were observed to be even higher in patients with well developed CCC. Further research including larger series and long-term follow-up is required to investigate this issue.     

Effect of isolated coronary artery ectasia on dispersion of P-wave and QT interval

BackgroundCoronary artery ectasia (CAE) is well-recognized, angiographic finding of abnormal coronary artery dilatation, and detected in 0.3–5.3% of angiographic studies. The gold standard for diagnosis this type of aneurysm is coronary angiography, which provides information about the size, sample, location and number of aneurysms. Despite growing prevalence in recent years, controversy still exists as to the pathogenetic mechanisms that underlie this entity. In this study we search the effect of isolated CAE on P-wave and QT interval dispersion.Patients and methodsTwenty patients (mean age: 60 ± 9.7 years) with isolated CAE (group I) were included in the study and 18 control subjects (group II) matched in sex and age. Both groups underwent a standard 12-lead surface electrocardiogram recorded at 50 mm/s. Maximal (P max) and minimal P-wave durations (P min) are measured. P dispersion (PD) was defined as the difference between P max and P min. QT interval was measured from the onset of the QRS complex to the end of the T-wave, defined as the return to the T–P isoelectric line. The mean of three consecutive intervals in each analyzable lead was taken for analysis. QT dispersion was defined as the difference between the longest and shortest QT intervals and the rate corrected with Bazett’s formula.ResultsP max (117.1 ± 4.6) and PD (34.2 ± 5.4) were significantly higher in ectatic patients (group I) than those of the control (group II) [P max (100.5 ± 5) and PD (18 ± 5.4)], while no significant difference between the two groups as regards P min.C QT duration (401 ± 4.4), QT dispersion (31.7 ± 3), and C QT dispersion (33.9 ± 3.3) were significantly higher in group I than those of group II [C QT duration (391.9 ± 2), QT dispersion (27.3 ± 1), and C QT dispersion (29 ± 0.9)]. While there were no statistically significant difference between the two groups as regards echo data (EDD, ESD, EF, LA, LVMI, and AO).ConclusionIsolated CAE were found to be associated with prolonged dispersion of P-wave and QT interval.