冠脉内成形及支架术前后QT离散度的变化

观察冠脉内成形＋支架术（ＰＴＣＡ＋Ｓｔｅｎｔ）对心绞痛患者ＱＴ离散度（ＱＴｄ）的影响。方法：选择成功行ＰＴＣＡ＋Ｓｔｅｎｔ术的２９例患者，无心肌梗死病史。取术前１ｄ～１０ｄ（３．８３±２．８８）ｄ和术后１ｄ～６ｄ（２．６９＋１．２６）ｄ两份心电图。从导联间最大ＱＴ间期（ＱＴｍａｘ）减去最小ＱＴ间期（ＱＴｍｉｎ）得到ＱＴｄ，同样得到校正的ＱＴｄ（ＱＴｃｄ）。结果：ＱＴｄ、ＱＴｃｄ术前为（５８．９７±１９．１５）ｍｓ、（６２．９±２１．３６）ｍｓ，术后（３２．０７±１０．１４）ｍｓ、（３２．５２±１３．３２）ｍｓ，（Ｐ＜０．００１，Ｐ＜０．００１）。ＱＴｍａｘ术前为（４１２．４±３３．９８）ｍｓ，术后为（３９２．４±２３．９）ｍｓ，有显著差异（Ｐ＜０．００１），但心率校正后的ＱＴｃｍａｘ术前为（４２９．２±３１．９９）ｍｓ，术后为（４２６．９±２６）ｍｓ，无显著差异（Ｐ＞０．５）。而ＱＴｍｉｎ及心率校正的ＱＴｃｍｉｎ术前（３５３．５±２４．５）ｍｓ、（３６６．３±２２．７）ｍｓ，术后（３６１±２０．７９）ｍｓ、（３９４．３±２４．１）ｍｓ，均有显著差异（Ｐ＜０．０５，Ｐ＜０．００１），且ＱＴｃｍｉｎ的差异更显著?

EFFECT OF CORONARY ANGIOPLASTY AND STENT IMPLANTATION ON QT DISPERSION

Objective:Dispersion of the QT interval (QTd) is a measure of inhomogeneity of ventricular repolarization.Because ischemia can increase the QTd,successful revascularization would improve the blood supply of the ischemic myocardium and reduce the QTd.We determined the effect of coronary angioplasty and stent implantation on QTd.Methods:Twenty nine patients with angina pectoris without prior myocardial infarction who underwent percutaneous transluminal coronary angioplasty (PTCA) and stent implantation were evaluated.Surface 12～18 leads electrocardiograms were selected 1～10 days before and 1～6 days after PTCA+Stent respectively,QT dispersion was determined from differences between the maximum and minimum QT intervals;similarly,QTcd was obtained.Results: QTd,QTcd before PTCA+Stent were (58.97±19.15)ms,(62.9±21.36)ms;after PTCA+Stent (32.07±10.14)ms,(32.52±13.32)ms (P<0.001,P<0.001).The QTmax before and after PTCA+Stent was significantly different (P<0.001)but QTcmax before and after PTCA+Stent was not (P>0.5).Both QTmin and QTcmin before PTCA+Stent were significantly different from after that;difference of QTcmin was more significant than that of QTmin.After PTCA+Stent,ventricular tachyarrhythmia in two patients disappeared.Conclusion:The major findings of this study were: ①a significant reduction in QTd,QTd follows successful PTCA+Stent;②the reduction in QTd after successful PTCA+Stent is due to prolongation of QTmin;③ ventricular tachyarrhythmia in two patients disappeared after PTCA+Stent.