优维显、欧乃派克对冠状动脉造影时QT离散度的影响

目的评价目前常用的两种非离子型造影剂优维显和欧乃派克对冠状动脉造影时 QT离散度 (QTD)参数和血流动力学参数的影响。方法 5 2例行冠状动脉造影的患者分为优维显和欧乃派克组 ,测量冠状动脉造影前和左、右冠状动脉第一次注药后连续 2 0秒的12导联体表心电图和左室造影前后的左室压力。结果优维显组注药后的 QT及 QTc明显延长 ,而欧乃派克组 QT及 QTc无明显变化。优维显、欧乃派克对 QTD和 QTc D均无明显影响。左室造影后优维显、欧乃派克均使左室舒张末压 (L VEDP)平均升高 3 mm Hg;比较优维显和欧乃派克对左室舒张末压的影响无明显差异。冠状动脉病变程度与造影剂对 QTD各参数的影响无明显相关。结论冠状动脉造影时 ,优维显和欧乃派克对 QT离散度均无明显影响 ;两者对冠状动脉造影时 QT离散度的影响也无明显差异。     

PTCA对冠脉狭窄患者QT离散度的影响

目的：探讨经皮冠状动脉成形术（PTCA）对冠状动脉狭窄患者术后QT离散度（QTD）的影响，方法：对行PTCA的83例患者进行了术前及术后1h,24h,3d,7d,30d体表心电图QTD的测定。并与同期行冠状动脉造影（CAG）存在冠状动脉狭窄的61例患者及63例健康人进行比较。结果：前两组冠脉狭窄患者QTD较健康人显著增大，PTCA使冠脉狭窄患者QTD显著缩小，而CAG则对冠脉狭窄患者的QTD无影响，结论：PTCA改善了心肌灌注，使心肌复极趋于均一，因此QTD缩小。     

冠状动脉病变严重程度、冠心病介入治疗对QT离散度的影响

QT离散度（QTd）是近年来发展起来的1项预测心脏复极同步的新指标。本研究旨在探讨冠状动脉病变严重程度、介入治疗对QTd及校正QTd（QTcd）的影响。     

冠状动脉病变严重程度、冠心病介入治疗对QT离散度的影响

QT离散度(QTd)能预测心律失常和猝死的发生。本研究旨在探讨冠状动脉病变严重程度、介入治疗对QTd及校正QTd(QTcd)的影响。1临床资料与方法选择完成冠状动脉造影且心电图及临床资料完整病例101例。排除心肌梗死、充血性心力衰竭、瓣膜性心脏病、左心室肥厚、高血压3级、心房纤颤、束支传导阻滞、预激综合症及使用I、III类抗心律失常药物的患者。冠脉造影提示的双支、3支病变病例亦排除在外。上述研究对象按如下方案进行分组:根据冠脉造影病变狭窄程度分组:①冠脉无狭窄组,病变狭窄<50%,为31例;②冠脉轻度狭窄组,病变狭窄≥50%且<70%,…     

冠状动脉病变严重程度、冠心病介入治疗对QT离散度的影响

QT离散度(QTd)是近年来发展起来的1项预测心脏复极同步的新指标.本研究旨在探讨冠状动脉病变严重程度、介入治疗对QTd及校正QTd(QTcd)的影响.     

冠状动脉旁路移植术对QT离散度的影响

目的：研究体外循环下冠状动脉旁路移植术（CABG）对QT离散度（QTd）的影响。方法：记录94例冠心病患者术前及术后第7天的12导同步心电图，对QT、QTc及QTd进行测量及分析。结果：术后QTd及QTcd均较术前明显减小，P〈0．01，差别有高度显著意义。结论：体外循环下CABG术后QTd及QTcd均明显小于术前。QTd和QTcd可作为观察CABG病人疗效和判断预后的便捷指标。     

冠状动脉旁路移植术对QT间期离散度的影响

目的　探讨冠状动脉旁路移植术 (CABG)对QT间期离散度 (QTd)的影响及其临床意义。方法　 6 2例非体外循环下行CABG的冠心病患者 ,分为不稳定型心绞痛 (A组 )、稳定劳力型心绞痛 (B组 )、合并陈旧性心肌梗死 (C组 ) ,15例冠脉造影正常者作为对照组 (D组 )。分别于术前和术后当天、2、4周及对照组相应时间记录 12导联同步心电图 ,对其QT间期测量 ,计算出QTd ,并进行统计学分析。结果　术前A、B、C 3组的QTd显著大于D组 (P <0 0 1～ 0 0 0 1) ,且A、C组大于B组(P <0 0 5 )。术后 2、4周各组QTd与术前相比均有缩短 (P <0 0 5～ 0 0 1)。A、B两组术后 4周QTd缩短值大于C组 (P <0 0 5 )。术后 4周LVEF恢复至 5 0 %以上者QTd缩短值显著大于LVEF仍低于 5 0 %者 (P <0 0 5 )。C组QTd≤ 70ms者术后QTd缩短值显著大于术前QTd >70ms者 (P <0 0 5 )。结论　QTd作为一种简单、可靠、廉价、无创的方法 ,可用于判断病情严重程度、不同类型冠心病手术疗效、评价和预测血运重建术的效果。     

冠状动脉成形术对急性心肌梗死QT离散度影响分析

目的 探讨冠状动脉病变程度、病变部位及经皮冠状动脉介入治疗(PCI)对急性心肌梗死(AMl)患者QT离散度(QTd)、心率校正QT离散度(correcteqd QT dispersion,QTcd)的影响.方法 对确诊的130例AMI患者于入院第5～10天行PCI治疗,其中单支血管病变68例(包括左前降支30例、右冠状动脉20例、左回旋支18例),多支血管病变62例,与100例同期冠状动脉造影结果 正常者(对照组)进行比较,对照分析术前1 d和术后1 d的标准18导联同步心电图QTd及QTcd.结果 AMI患者QTd及QTcd均较对照组延长(均P<0.05),且多支血管病变组QTd、QTcd较单支血管病变组延长(均P<0.05).冠状动脉病变部位对QTd和QTcd无明显影响(均P>0.05).PCI术后QTd和QTcd较术前缩短(均P<0.05),而单独进行冠状动脉造影(coronary angiography,CAG)对QTd、QTcd无明显影响(P>0.05).结论 AMI患者QTd、QTcd明显高于正常人,且随着血管病变范围增大而变异增大,冠状动脉病变部位对QTd、QTcd无影响.成功的PCI能显著减小AMI患者QTd以及QTcd.     

QT离散度与冠状动脉狭窄病变的关系及冠状动脉支架置入术对它的影响

目的探讨QT离散度(QTd)与冠状动脉狭窄病变程度和范围的关系及支架置入术前后QTd的变化。方法分析119例经选择性冠状动脉造影患者的心电图资料,观察不同狭窄程度和范围的冠状动脉病变QTd指标以及冠脉重度狭窄者支架置入术前后QTd的变化。结果冠脉正常组QTd为46.7±10.3m s,轻度狭窄组(49.4±10.6m s)与正常组之间无明显差异(P>0.05)。重度狭窄组(68.5±10.7m s)与中度狭窄组(60.8±10.5m s)相比,中度狭窄组与轻度狭窄组相比,QTd均显著增大(P<0.01)。单支病变组QTd为55.3±10.4m s,与正常组比较差异显著(P<0.01);多支病变组(69.3±10.1m s)与双支病变组(62.5±10.2m s)比较,双支病变组与单支病变组比较,QTd均显著增大(P<0.05)。重度狭窄组支架置入术后QTd为44.9±10.1m s,与术前比较明显减小,差异有显著性(P<0.01)。结论QTd增大提示冠脉狭窄更严重,病变范围更广泛。成功的支架植入术可明显缩短冠脉重度狭窄患者QTd。     

冠脉成形术前后运动试验心电图QT离散度的变化

ＱＴ离散度（ＱＴｄｉｓｐｅｒｓｉｏｎ,ＱＴＤ）是反映心脏各部位心肌复极离散程度的指标。研究表明,当心肌局部缺血、室壁运动异常、心肌肥厚或心功能不全时,可出现静息心电图ＱＴＤ异常变化〔１〕,而有关运动负荷下的ＱＴＤ变化的观察报道较少。本文将冠心病冠脉成...     

冠状动脉病变支数及介入治疗对冠心病患者QT离散度的影响

目的探讨冠状动脉病变支数及介入治疗对QT离散度(QTd)的影响。方法对72例成功进行经皮冠状动脉腔内成形和支架术的冠心病患者,计算手术前后12导联同步心电图QTd及校正后QTd(QTcd)。结果冠心病不同类型和冠状动脉病变不同支数术前QTd及QTcd无明显差别(P>0.05),术后QTd及QTcd均较术前显著下降[稳定型心绞痛、不稳定型心绞痛和急性心肌梗死QTd为(49±20)msvs(57±24)ms、(46±18)msvs(61±18)ms、(48±18)msvs(61±20)ms,P<0.05;QTcd为(56±28)msvs(68±25)ms、(56±18)msvs(71±20)ms、(59±20)msvs(69±22)ms,P<0.05];单支病变组术后QTd、QTcd较其他病变组下降显著[术后单支血管病变与2支病变、3支病变的比较为QTd(38±18)msvs(50±24)msvs(52±16)ms,F=15.86,P<0.01;QTcd(45±20)msvs(56±18)msvs(58±27)ms,F=9.60,P<0.01]。结论介入治疗前冠心病患者QTd及QTcd与受累病变血管支数无关,在介入治疗后随着心肌缺血及心室复极不均一性的改善而降低。     

造影剂对冠脉造影患者肾功能的影响

目的 了解造影剂进行冠状动脉造影时对肾功能的影响。方法 前瞻性观察了141例应用非离子型低渗性造影剂碘海醇或等渗性造影剂碘克沙醇进行冠状动脉造影患者的肾功能变化，于造影前、造影后第1天、第2天分别测定血尿素氮（BUN）、血肌酐（SCr）、血胱抑素C（cystatin C，CysC）、尿微量白蛋白（mALB）、尿转铁蛋白（TRF）、α1-微球蛋白（α1-MG）、N-乙酰基-β-D氨基葡萄糖苷酶（NAG）及肌酐。结果 与造影前比较，造影后第1天血CysC显著升高（P〈0．01），超过正常范围，造影后第2天血CysC仍高于造影前水平（P〈0．01），但已降至正常范围；与造影后第1天比较，造影后第2天血cysC显著下降（P〈0．01）。血BUN、SCr及电解质造影前后无显著变化；与造影前比较，造影后第1天mALB、TRF、α1-MG和NAG均显著升高（P〈0．01），超过正常范围，造影后第2天，NAG仍显著高于造影前（P〈0．01），α1-MG仍高于造影前（P〈0．05），mALB和TRF恢复到造影前水平（P〉0．05）；与造影后第1天比较，造影后第2天mALB明显下降（P〈0．05），TRF、α1-MG和NAG均显著降低（P〈0．01）。结论 在无基线肾功能不全患者中，未见造影后发生CIN的病例，部分患者存在一过性轻度蛋白尿、尿酶升高；年龄与糖尿病可能是影响造影后第1天血CysC变化的主要危险因素。     

Effects of Ischemia and Reperfusion on QT Dispersion During Coronary Angioplasty

The effects of ischemia and reperfusion on QT interval dispersion (QTD: QT_max-QT_min in the 12-lead ECG) were analyzed in 15 patients (12 males, 57 ± 13 years) undergoing coronary angiopiasty (PTCA). AH patients had single-vessel coronary artery disease (only one ≥ 85% stenosis in a major coronary artery) and normal left ventricular function. AH were in sinus rhythm with normal atrioventricular and intraventricular conduction on the surface ECG. No patient was on therapy that could affect the QT interval. The ECG was recorded (all 12 leads simultaneously) at 50 mm/s speed before the first balloon inflation, at the end of the first inflation during PTCA, and at 30" and 60" during reperfusion following the first inflation. In order to avoid ischemic preconditioning, only recordings of the first inflation were used. In each tracing QT_max and QT_min were evaluated. All values were rate corrected using a simple linear equation (QT linear corrected = QT + 0.154 [1-RR]). QTD increased significantly during both ischemia and reperfusion. QT_max was not changed by ischemia and was increased by reperfusion. QT_min was reduced by ischemia and increased by reperfusion. These results indicate that both ischemia and reperfusion alter ventricular repolarization, inducing a less homogeneous ventricular recovery pattern.     

QT 离散度与冠心病关系的研究进展

QT离散度（QTd）对冠心病预测心肌缺血程度、范围及预后具有重要参考价值,近年来受到广泛关注。QTd[体表心电图12导联中最大QT间期（QTmax）与最小QT间期（QTmin）之间的差值]反映心室肌细胞复极过程不均一性与冠心病心肌缺血有关系。QT离散度可用于评价冠状动脉病变特点,从而指导冠心病患者血运重建,对评估介入治疗术前及术后预后具有重要的临床意义。     

老年冠心病及血运重建对QT离散度的影响

目的 观察老年冠心病患者经皮冠状动脉介入治疗(PCI)术前后QT离散度(QTd)的变化特点与趋势,并与正常对照组进行对比,探讨QTd与冠状动脉狭窄程度和范围的关系及经皮冠状动脉腔内成形术和PCI对其的影响,以期为临床寻找一种评价PCI术预后的有效无创方法.方法 已行冠状动脉造影术的≥60岁冠心病患者679例,分为冠心病组(经冠状动脉造影证实有单支或多支病变,狭窄程度≥50％)536例.对照组(同期住院冠状动脉造影狭窄程度＜50％)143例.术前分别描记两组的常规12导联心电图,测量QTd、校正QT离散度(QTcd).经冠状动脉造影证实狭窄程度≥75％的393例冠心病患者行PCI术,并再分为3个亚组:单支病变组176例,双支病变组118例,3支病变组99例.对照组:同期住院冠状动脉造影狭窄程度＜50％患者143例.PCI各组术前、术后1天、7天,分别检测QTd、QTcd,进行比较.结果 冠心病组胆红素明显低于对照组(P＜0.01).冠心病组的总胆固醇 (TC)、低密度脂蛋白胆固醇(LDL-C)和血尿酸明显高于对照组(P＜0.01),QTd和QTcd明显比对照组延长(P＜0.01),冠心病3个亚组的QTd和QTcd在术前、术后1天和术后7天均呈逐渐下降趋势,3个亚组在组间、不同时点以及组间和不同时点的交互作用中差异均有统计学意义.单支病变组术前QTd(48.52±12.35)ms,术后1天(41.23±13.35) ms,术后7天(41.12±12.61) ms,术前QTcd(55.34±15.81)ms,术后1天(48.62±14.93) ms,术后7天(48.23±13.65) ms;双支病变组术前QTd(53.26±16.95) ms,术后1天(44.54±14.63)ms,术后7天(43.96±15.32) ms,术前QTcd(59.41±16.72)ms,术后1天(50.35±15.43) ms,术后7天(49.94±15.35)ms;3支病变组术前QTd(58.43±13.72) ms,术后1天(52.82±13.66)ms,术后7天(52.76±13.32)ms,术前QTcd(65.91±18.53)ms,术后1天(60.21±16.38) ms,术后7天(60.19±15.74) ms.结论 QTd、QTcd在冠心病患者明显升高,PCI术后明显降低,并与冠状动脉狭窄的程度和范围有关.说明QTd、QTcd可以作为临床上预测心肌缺血,评估PCI术后预后的有效无创指标.     

Effects of aging and gender on QT dispersion in an overtly healthy population

The objective of this study was to measure the normal variation of QT dispersion (QTd) with respect to age and gender. The QT interval is a measure of the duration of ventricular depolarization and repolarization, while the QTd is a measure of the variability of the ventricular recovery time. The QTd has been suggested as a means of identifying those patients at risk for sustained ventricular tachyarrythmias and sudden cardiac death (SCD). A total of 250 patients (120 women, 130 men; age range 20-86 years) were recruited for this study. The QT intervals were measured in each of the 12 standard leads of the electrocardiogram. Data are presented as mean (mu) +/- SD. The QTd did not vary significantly within the same gender. A significant difference (P < 0.001) was noted in QTd between men (age [mu] = 53.3 +/- 15.6 years, QTd = 0.044 +/- 0.019 s) and women (age [mu] = 52.1 +/- 15.1 years, QTd = 0.034 +/- 0.015 s). Overall, men had a greater QTd, while women had a longer QT. In conclusion, we found that men had a longer QTd, which may explain the increased risk of SCD. However, women have a longer QT interval with a smaller QTd. A longer QTmin, as opposed to a longer QTmax, is responsible for the shorter QTd in women. This longer QTmin in women may predispose to an increased risk of drug induced torsades de pointes.     

非离子型低渗造影剂相关性肾损害的临床分析

目的:了解冠脉介入治疗患者造影剂相关性肾病危险因素的发生情况。方法:收集240例接受冠脉介入治疗患者的临床资料,分为合并症组和无合并症组,合并症组又分为高血压组、糖尿病组、和高血压合并糖尿病组,分析检查者的血肌酐变化以及CIN发生的情况。结果:240例患者中,有合并症组出现CIN16例,而无合并症组无一例出现CIN,有合并症组肌酐上升幅度较无合并症组高,两组间差异有统计学意义,同时发生肌酐上升的例数亦较无合并症组高,两组间比较差异有统计学意义;而糖尿病和高血压组两组发生CIN的情况大致相同,糖尿病合并高血压组发生CIN的例数明显高于其他2组。结论:行冠脉介入治疗的患者,存在CIN的危险因素十分普遍,早期给予积极而有效的预防措施十分必要。     

Impact of electrocardiogram recording format on QT interval measurement and QT dispersion assessment

The aim of this study was to determine the effect of recording conditions on the operator dependent measures of QT dispersion in patients with known and/or suspected repolarization abnormalities. Among several methods for risk stratification, QT dispersion has been suggested as a simple estimate of repolarization abnormalities. In a cohort of high and low risk patients, different components of the repolarization process were assessed in the 12-lead ECG using three different paper speeds and amplifier gains. To assess measurement error and reproducibility, a straight line was repeatedly measured. The operator error was 0.675 +/- 0.02 mm and the repeatability of the measurement error was 31 +/- 6%. The QT interval was most frequently measurable in V2-V5. Depending on the lead selected for analysis, the incidence of visible U waves was greatest in the precordial leads with high amplifier gain and low paper speed, strongly affecting QT interval measurement. The timing of the onset of the QRS complex (QRS onset dispersion) or offset of the T wave was strongly dependent on the paper speed. Paper speed, but not amplifier gain, had a significant shortening effect on the measurement of the maximum QT interval. As QT interval measurement in each ECG lead incorporates QRS onset and T wave offset (depending on the number of visible U waves), the dispersion of each of these parameters significantly affected QT dispersion. Thus, QT dispersion appears to reflect merely the presence of more complex repolarization patterns in patients at risk of arrhythmias.