冠状动脉旁路移植术对QT、QTc、JT离散度的影响

目的　探讨冠状动脉旁路移植术 (Coronary artery bypass graftings,CABG)对冠心病患者 QT间期离散度(QTd)、QTc离散度 (QTcd)及 JT离散度 (JTd)的影响。方法　测定 33例 CABG术前和术后的 QTd为 CABG组 ,并以 33例确诊为冠心病行冠状动脉造影 ,而暂未行 CABG手术和装支架的病人作对照组。结果　 1CABG前和对照组比较 QTd无显著增大 (P>0 .0 5 )。 2 CABG组术后病人的 QTd、QTcd及 JTd显著减小 (P<0 .0 5 )。 3对照组冠状动脉造影术后 QTd、QTcd及 JTd与术前比较 ,无明显改变 (P>0 .0 5 )。结论　 CABG能使 QTd、QTcd及 JTd减小     

急诊PCI和延期PCI患者QT离散度对比分析

目的对比不同时期经皮冠状动脉介入治疗（PCI）对急性心肌梗死（AMI）患者QT离散度（QTd）的影响。方法入选78例患者根据PCI手术时间分为急诊PCI组和延期PCI组,计算各患者术前和术后心电图QTd及心率校正QT间期离散度（QTcd）。然后观察两组术前和术后QTd及QTcd的差异。结果两组PCI组术后QTd及QTcd均较术前缩短（P<0.05）。与延期PCI组术后QTd相比,急诊PCI组术后QTd及QTcd显著缩短（P<0.05）。结论急诊PCI和延期PCI均能缩短AMI患者的QTd,但与延期PCI相比,急诊PCI术后QTd缩短更显著,表明急诊PCI疗效更佳。     

冠状动脉旁路移植术对冠心病QT间期离散度的影响

为探讨冠状动脉旁路移植术 (CABG)与心室复极离散度 (QTd)的关系 ,对冠心病冠状动脉旁路移植术患者 32例术前、术后和未行冠状动脉旁路移植术患者 32例的心室复极各参数进行分析发现 :1 CABG组术前术后QTd、QTcd、QTLcd组内比较 ,术后QT间期离散度减少 ,有明显的统计学差异 (P <0 0 1)。2 CABG术后QTd、QTcd、QTLcd与未行CABG术QTd、QTcd、QTLcd组间比较、术后QT间期离散度减少 ,有明显的统计学差异 (P <0 0 1)。 3 非手术治疗组前后的QTd、QTcd、QTLcd比较 ,无明显差异 (P >0 0 5) ,结果表明 :冠状动脉旁路移植术能改善心室复极离散     

急诊经皮冠状动脉介入治疗对QT间期离散度的影响

目的探讨急诊经皮冠状动脉介入治疗（PCI）后对QT间期离散度（QTd）的影响。方法对70例ST段抬高的急性心肌梗死（AMI）患者行急诊PCI前和PCI后24h内12导联同步心电图QT间期、校正QT间期（QTc）、QTd及校正QT间期离散度（QTcd）4项指标进行对比分析。并监测严重心律失常发生情况。结果PCI后QT和QTc与术前差异无显著性,而QTd和QTcd则较术前明显减少,差异有显著性意义（P<0.01）。28例术前有恶性心律失常,其QTd明显高于无心律失常的患者[（70±18）msvs（52±15）ms,P<0.01];术后QTd降至（45±16）ms（P<0.01）,室性心律失常消失或减少。结论急诊PCI能显著减少AMI患者的QTd和QTcd,降低急性期恶性心律失常的发生。     

冠心病患者冠状动脉搭桥术前后QT离散度的变化

目的 探讨冠状动脉搭桥(CABG)术对同步12导联心电图QT离散度(QTd)的影响。评估其临床疗效。方法回顾性分析近4年来126例CABG术者术前与术后不同时间的QTd及心率校正的QT离散度(QTcd)。结果术前的QTd及QTcd均明显高于正常。术后QTd、QTcd均明显减少。较术前差异性显著。结论CABG治疗冠心病疗效显著。QTd及QTcd可作为CABG后血管通畅率的无创性、有效检测指标。     

冠状动脉狭窄老年患者PTCA术后QT离散度变化

目的 :观察冠状动脉成形术 （PTCA）对老年冠脉狭窄患者心肌复极的影响。方法 :连续测量了 6 8例冠状动脉狭窄老年患者 PTCA术前术后体表心电图的 QT间期与 QT离散度 （QTd） ,并与 5 3例无狭窄对照组比较。结果 :冠状动脉狭窄组较无狭窄组 QT间期显著延长 ,QTd明显增加 （QTm ax分别为 :45 3± 43m s和 392± 35 m s;QTc-max分别为 :482± 49m s和 439± 37ms;QTd为 74± 33m s和 2 9± 15 m s;QTcd为 78± 37ms和 32± 17m s,P<0 .0 1） ;PTCA使 QT间期缩短 ,QTd缩小 （QTcm ax:术前 482± 49ms,术后 1周为 45 2± 40 ms;QTcd在术前 78±37ms,术后 2 4h内 6 3± 2 6 m s,术后 1周为 6 0± 32 m s;QTd在术前 75± 34 m s,术后 2 4h内为 5 8± 2 5 ms及术后 1周 5 6± 31ms,P<0 .0 5 ）。结论 :心肌灌注增加明显缩短 QTd离散度 ,表明心肌复极获得改善 ,这可能有利于减少心律失常的发生。     

QT离散度对PCI术后冠状动脉再狭窄的临床评估及应用价值研究

目的对经皮冠状动脉介入（PCI）术前、术后有及无再狭窄病人行QT离散度（QTd）分析,评估QTd对PCI术后冠状动脉再狭窄的临床应用价值.方法选择PCI术后冠状动脉再狭窄病人36例,随机选择40例PCI术后无再狭窄病人对照比较研究,于PCI术前及术后3个月分别行12导联心电图测量QTd和计算较正QTd（QTcd）,同时行冠状动脉造影检查,观察QTd及QTcd对PCI术前、术后有无再狭窄的影响变化.结果 36例再狭窄组病人PCI术前、术后QTd及QTcd无明显差异,40例无再狭窄组病人PCI术后比术前QTd及QTcd有明显缩短（P〈0.05）.再狭窄组的血管病变程度PCI术前、术后QTd及QTcd无明显变化,无再狭窄组的PCI术后比术前单支血管病变QTd及QTcd缩短（P〈0.05）,双支及3支血管病变QTd及QTcd明显缩短（P〈0.01）.PCI术后再狭窄组的多支病变数较无再狭窄组的多支病变数的发生率明显增多.结论 QTd及QTcd对评估PCI术后再狭窄有明显的临床应用价值.     

冠心病冠状动脉介入治疗前后QT离散度的比较

目的　探讨成功的冠状动脉介入手术 (PTCA及冠状动脉内支架置入术 )对冠心病患者QT离散度 (QTd)的影响。方法　考察 2 5 2例冠心病患者成功进行介入手术前后十二导联同步心电图的结果 ,计算QTd和校正的QT离散度 (QTcd)并进行对比分析。结果　 2 5 2例冠心病患者经PTCA或加支架植入术共处理的病变有 383处 ,除 2 8例外 ,术后QTd缩短明显 ;介入手术前后QTd及QTcd比较有显著性差异 (P <0 0 5 ) ;血流灌注术后均达到TIMIⅢ级与Ⅱ级 ,两组术前QTcd比较以及术后下降幅度无显著差异 (P >0 0 5 ) ;单支与多支病变术前QTcd无显著差异 (P >0 0 5 ) ,术后下降幅度则有显著差异 (P <0 0 5 )。结论　冠心病经成功的介入治疗后QT离散度明显减小 ,QT离散度可作为介入手术后心肌再灌注成功的一个参考指标。     

左、右冠脉支架术后围术期风险与区域性QT离散度的关系

目的通过对冠状动脉内PTCA及支架术后病人的QT间期离散度区域性差别的研究,进一步估测左右冠脉内的介入操作所固有的围术期风险性。方法对130例冠脉造影证实冠脉管径狭窄≥70%而成功进行PTCA及支架术后的患者术前、术后第1、2、3天进行12导联心电图检查。结果①与PCI术前相比,术后第1、第2、第3天QT离散度均有明显降低,P<0.05,校正QT离散度也明显降低(P<0.05);而术前、术后心率则无明显变化。②右冠状动脉的介入操作后QT离散度和QTc离散度均大于左冠状动脉的介入治疗后。③QTd、QTcd在右冠状动脉介入操作者下壁导联长于前壁导联,反之左冠状动脉介入操作者前壁导联长于下壁导联。结论成功PCI可降低冠心病患者的QT离散度,从而可能预防心血管事件的发生,提高总体安全性,但恶性心律失常的发生几率右冠脉支架后仍然可能比左冠脉支架后大,所以决不能掉以轻心。     

冠状动脉搭桥术对QT离散度的影响

目的探讨冠状动脉搭桥术(CABG)对QT离散度(QTd)的影响及其临床意义。方法分析51例CABG成功的患者术前1d,术后7d、14d、30d的心电图,测定其QTd及心率校正的QT离散度(QTcd),同时观察心绞痛缓解程度,心功能及左室射血分数的变化。结果患者术后7dQTd、QTcd较术前显著减少(P<0.01),术后2W仍有下降(P<0.05),术后14d恢复到正常范围,且这一结果与临床指标明显相关。结论QTd可作为CABG疗效判断的一项可行指标。     

Effects of coronary revascularization and concomitant aneurysmectomy on QT interval duration and dispersion

A reduction in QT dispersion (QTd) has been previously shown in patients receiving thrombolytics and undergoing coronary artery bypass grafting (CABG). The purpose of the present study was to investigate changes occurring in corrected QT intervals or QT dispersion after CABG and concomitant aneurysmectomy in the same session. The study population included 43 patients with coronary artery disease with left ventricular aneurysm (LVA). The control group included 32 patients with coronary artery disease without LVA. The study patients underwent CABG and aneurysmectomy in the same surgical session. Corrected maximum and minimum QT interval duration (QTcmax and QTcmin) and corrected QT dispersion (QTcd) were measured in the study patients before and after surgery. QTcmax and QTcd in the patients with LVA were significantly higher than in the patients without LVA (P < .001 and P < .001, respectively). QTcmax and QTcd in the patients with LVA were significantly shortened after surgery (P < .001 and P < .001, respectively). This study showed that QTcmax and QTcd values are significantly reduced after CABG and concomitant aneurysmectomy. We have suggested that coronary revascularization and left ventricular reconstruction in the same session have beneficial effects on QT interval duration and dispersion.     

急性心肌梗死恢复期PTCA及支架置入术对QT离散度的影响

目的　观察急性心肌梗死 (AMI)恢复期 (2～ 4周 )行经皮冠状动脉腔内成形术 (PTCA)及支架置入术对QT离散度 (QTd)的影响。方法　选择 5 7例AMI恢复期的患者 ,分别记录PTCA及支架置入术前 1d ,术后 1h的 12导联同步心电图 ,测量QTd及校正的QTd(QTcd) ,并与 86例同期行冠状动脉造影结果正常者进行对照。结果　AMI组行PTCA及支架置入术前最大QT间期 (QTmax) ,最小QT间期 (QTmin) ,QTd及QTcd均较对照组明显增大 ,差异有显著性。前壁与下壁AMI之间上述指标差异无显著性。成功的PTCA及支架置入术后QTmax,QTmin,QTd及QTcd比术前明显缩短 ,两者相比差异有显著性。而单纯行冠状动脉造影对QT离散度无明显影响。结论　AMI患者QTd及QTcd显著高于正常人 ,而AMI恢复期成功的PTCA及支架置入术可使增加的QTd及QTcd显著缩短 ,从而减低AMI后恶性心律失常和心源性猝死的发生率 ,改善患者的远期预后。     

急性颅脑损伤患者心电图QT离散度的特点与意义

目的探讨急性颅脑损伤（ABI）患者心电图QT、JT间期变化对其轻重程度的判断及预后评估的意义。方法根据格拉斯哥昏迷评分,将101例ABI患者分为轻、中、重型三组;根据患者有无蛛网膜下腔出血（SAH）,分为SAH组及无SAH组。检测各组伤后24h内心电图的QT间期及JT间期,计算QT离散度（QTd）、校正的QT离散度（QTcd）、JT离散度（JTd）及校正的JT离散度（JTcd）;根据格拉斯哥预后评分判断预后,对其不同组间的各值进行统计学分析。结果轻、中、重型ABI患者的心电图QTd、QTcd、JTd、JTcd存在显著性差异,且SAH组各指标均升高,较无SAH组有显著统计学差异（P〈0．01或〈0．05）,并与预后有明显的相关性（P均〈0．01）。结论QTd、QTcd、JTd、JTcd对判断ABI程度及其预后评估有重要参考价值,可作为预测患者临床转归的指标,并且有助于早期临床干预。     

Effect of slow coronary flow on electrocardiographic parameters reflecting ventricular heterogeneity

QT interval dispersion reflects regional variations in ventricular repolarization and cardiac electrical instability. Previous studies have showed that QT interval dispersion changes during episodes of myocardial ischemia. Slow coronary flow (SCF) in epicardial coronary arteries is a rare and unique angiographic finding. Whether this pattern of flow is associated with electrocardiographic abnormalities is unknown. Therefore, this study was designed to investigate whether SCF results in electrocardiographic (ECG) changes compared to normal coronary flow. For this aim 24 patients with angiographically proven SCF who had no obstructive coronary lesion (group I) and 25 patients without coronary artery disease (group II) were included in the study. Both groups underwent a routine standard 12-lead surface electrocardiogram recorded at 50 mm/s during rest. QT dispersion (QTd), corrected QT (QTc), and corrected QT dispersion (QTcd) were calculated. Distributions of sex, age, body mass index (BMI), and cardiac risk factors were similar in the 2 groups. Mean heart rate was similar in the 2 groups (74 +/-8 vs 77 +/- 7 p > 0.05). Mean QRS interval durations were similar in the groups (92 +/-7 vs 90 +/-6 ms p > 0.005). In group I, QTd, QTcd, and QTc, were significantly higher than in group II (QTd: 73 +/-14 vs 40 +/-14; QTcd: 71 +/-15 vs 42 +/-9; QTc: 414 +/-14 vs 388 +/-13, respectively p <0.05). In conclusion, SCF was found to be associated with prolonged QT interval and increased QT dispersion. Ischemia in microvascular level and/or altered autonomic regulation of the heart may be responsible mechanisms.     

QT离散度对心衰患者心脏事件的预测价值

目的探讨QT离散度(QTd)、校正QT离散度(QTcd)及心率校正QT间期(QTc)对心衰患者心脏事件的预测价值。方法回顾性研究了106例充血性心力衰竭(CHF)患者QTd、QTcd、及QTc的资料。结果心脏事件发生组CHF病人(Ⅰ组)QTd、QTcd、QTc、QTcd/QTc与无心脏事件发生组(Ⅱ组)比较有显著的统计学差异(P<0.05、<0.01、<0.05、<0.001)。结论QTd、QTcd、QTc、QTcd/QTc是心衰病人心脏事件独立预测因子,QTcd/QTc准确性最高。     

冠心病介入治疗对QT离散度的影响

目的探讨冠心病介入治疗对QT离散度的影响。方法选择127例行冠状动脉造影且心电图资料完整的患者,据造影结果分为对照组42例,治疗组85例,分别测定QT离散度(QTd)及校正QT离散度(QTcd)并进行比较。结果(1)介入治疗前治疗组与对照组相比QTd及QTcd均明显延长,统计学上差异有显著性意义(P<0.05)。(2)介入治疗后QTd及QTcd明显缩短,与介入治疗前相比,统计学上差异有显著性意义(P<0.05)。(3)介入治疗后QTd及QTcd与对照组比较,差异无显著性意义(P>0.05)。结论成功的介入治疗可缩短QT离散度,改善心肌的复极离散程度,减少心脏危险事件的发生。     

急性心肌梗死患者经皮冠状动脉介入治疗对心电图QT离散度的影响

为探讨经皮冠状动脉介入治疗对急性心肌梗死患者心电图QT离散度的影响及其临床意义 ,将我院资料较完整的 138例患者 ,分心肌梗死发病 6h内 (72例 )和 6h以上 (6 6例 )两组 ,测算术前和术后第 1天心电图QT间期、QT离散度、心率校正QT间期和心率校正QT离散度。结果发现 ,两组QT间期和心率校正QT间期术后与术前相比均无显著性差异 ;但术后QT离散度和心率校正QT离散度较术前显著减小 (P <0 .0 1) ,且发病 6h以内组显著小于 6h以上组 (P <0 .0 5 ) ;两组住院期间死亡率分别为 4 .2 %和 7.6 % (P =0 .394 )。结果提示 ,成功的介入治疗能显著减小心肌梗死患者的QT离散度 ,介入治疗施行得越早则减小QT离散度的效果越好。     

Effects of isolated coronary artery ectasia on electrocardiographic parameters reflecting ventricular heterogeneity

Isolated coronary ectatic but otherwise normal epicardial coronary arteries are an infrequent angiographic finding. We sought to determine whether coronary artery ectasia (CAE) may alter QT-interval duration and dispersion. The study population consisted of 24 patients with isolated CAE and otherwise normal epicardial coronary arteries (group 1) and sex- and age-matched subjects with atypical chest pain and otherwise normal coronary flow (group 2). Both groups underwent a routine standard 12-lead surface electrocardiogram recorded at 50 mm/s during rest. QT dispersion (QTd), corrected QT (QTc), and corrected QT dispersion (QTcd) were calculated. Distribution of sex, age, body mass index, and cardiac risk factors were similar in the 2 groups. Mean heart rate was similar in the 2 groups (74 ± 10 vs 70 ± 7, P > .05). In group 1, QTd, QTcd, and QTc were significantly higher than those of group 2 (QTd, 40 ± 17 vs 29 ± 10 milliseconds [P < .05]; QTcd, 43 ± 19 vs 30 ± 10 milliseconds [P < .05]; QTc, 410 ± 21 vs 397 ± 19 milliseconds [P < .05]). In conclusion, CAE was found to be associated with prolonged QT interval and increased QTd. Microvascular dysfunction and/or ischemia may be responsible mechanisms.