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 percutaneous coronary intervention on QT dispersion in elderly patients with coronarv artery disease

Objective To evaluate the influences of percutaneous coronary intervention（PCI） on QT dispersion,and then explore the relationship between QT dispersion and the extent and severity of coronary artery stenosis in elderly patients with coronary artery disease（CAD）.Methods 679 CAD patients（≥60 years old） who underwent coronary angiography（CAG） were divided into CAD group,536 patients（single or multiple vessels disease according to CAG,luminal narrowing to 50%or more） and control group,143 patients（luminal narrowing under 50%）.The electrocardiogram data were collected and QTd,QTcd were measured before CAG in two groups.CAG confirmed the luminal narrowing to 75%or more in 393 PCI patients who got PCI and the patients were further divided into three subgroups：176 single-,118 double-and 99 triple-vessels disease patients according to the number of vessels with significant stenosis.Control group（luminal narrowing under 50% according to CAG） included 143 patients.QTd,QTcd were measured at day 1 and day 7 after PCI.Results Total bilirubin in CAD group was significantly lower than that in control group（P0.01）.TC,LDL-C and uric acid in CAD group were significantly higher than those in control group（P0.01）,QTd and QTcd records in CAD group were significantly longer than those in control group（P0.01）.In CAD three subgroups,before PCI,day 1 and day 7 after PCI,QTd and QTcd records showed decline tendency,the differences of interblock,time dissimilarity and interaction of interblock with time dissimilarity between three subgroups showed statistical significance.In single-vessel group,QTd before PCI was（48.52±12.35） ms,day 1 after PCI（41.23±13.35） ms,day 7 after PCI（41.12±12.61） ms,QTcd before PCI was（55.34±15.81） ms,day 1 after PCI（48.62±14.93） ms,day 7 after PCI（48.23±13.65） ms;in double-vessels group QTd before PCI was（53.26±16.95） ms,day 1 after PCI（44.54±14.63） ms,day 7 after PCI（43.96±15.32） ms,QTcd before PCI（59.41±16.72） ms,day 1 after PCI（50.35±15.43） ms,day 7 after PCI（49.94±15.35） ms;in triple-vessels group QTd before PCI was（58.43±13.72） ms,day 1 after PCI（52.82±13.66） ms,day 7 after PCI（52.76±13.32） ms,QTcd before PCI（65.91±18.53） ms,day 1 after PCI（60.21±16.38） ms,day 7 after PCI（60.19±15.74） ms.Conclusion QTd and QTcd raise significantly in CAD patients,and after PCI,QTd and QTcd decrease.QTd and QTcd can reflect the severity and range of coronary artery stenosis as valid indexes in evaluating myocardial ischemia.