冠状动脉旁路移植术后心电图QT离散度的变化及其临床意义

Changes of QT dispersion in electrocardiogram after coronary artery bypass graft

目的 :探讨冠状动脉 (冠脉 )旁路移植术后心电图 QT离散度 (QTd)变化的临床意义。 方法 :对 4 8例冠脉 3支或 3支以上病变需行旁路移植术患者 ,采用 1 2导联多功能心电图监测仪 ,测定术前 1 d、手术结束时以及术后 1～ 7d的心电图QTd的变化。 结果 :术前 1 d的 QTd平均为 (5 6 .32± 2 .2 5 ) ms,手术结束时及术后 3d内的 QTd均比术前增加 ,以术后 2 d最高 ,为 (6 3.2 8± 2 .80 ) m s(P<0 .0 1 ) ,QTd在术后 4 d开始下降 ,术后 7d QTd已低于术前水平 ,达 (4 8.6 3± 1 .5 4 ) ms(P<0 .0 1 )。结论 :冠脉旁路移植患者术后心电图 QTd增加可持续 3d,表明心室肌复极具有不稳定性和不同步性 ,术后 4～ 7d才趋于稳定。

Objective:To study the significance of QT dispersion(QTd) changes in electrocardiogram(ECG) after coronary artery bypass graft. Methods:Forty eight patients scheduled for elective coronary artery bypass graft were studied. The changes of QTd were monitored by 12 lead electrocardiogram system before surgery (as baseline values), at the end of surgery, and 1 4 d and 7 d after surgery.Results:The baseline values for QTd was (56.32±2.25) ms.QTd were significantly longer as compared to the baseline values ( P <0.01) 1 3 d after surgery, with the longest being (63.28±2.80) ms on the 2nd day after surgery. QTd began to decrease on the 4th day after surgery and it was significantly shorter on the 7th day [(48.63±1.54) ms] as compared to baseline values( P <0.01).Conclusion: QTd in patients receiving coronary artery bypass are longer 1 3 d after surgery, indicating that myocardium process repolarization is of non stabilization and non synchronism until the 4th day after surgery.