冠状动脉粥样硬化性心脏病患者QT离散度与血浆内皮素和胰岛素敏感性的关系

Relationships between QT Dispersion and Plasma Endothelin Levels, Insulin-Sensitivity in Patients with Coronary Heart Disease

为探讨冠状动脉粥样硬化性心脏病患者QT离散度与血浆内皮素水平、胰岛素敏感性及严重室性心律失常的关系 ,对 47例冠状动脉粥样硬化性心脏病患者和 2 0例健康对照者进行口服葡萄糖耐量试验、胰岛素和C肽释放试验 ,并测定血浆内皮素水平。急性心肌梗死患者糖耐量试验在梗死后第四周进行 ,第一天血样本也检测内皮素水平。所有对象在抽血当天同步记录常规 12导联心电图测算QT离散度。以QT离散度为因变量 ,以 9个胰岛素敏感性指标和血浆内皮素水平为自变量 ,进行逐步回归和 /或简单相关分析。结果发现 ,冠状动脉粥样硬化性心脏病各亚组内皮素被有效选入回归方程 ,QT离散度与内皮素呈显著正相关 ;急性心肌梗死组空腹血糖也被有效选入回归方程 ,但QT离散度与空腹血糖呈负相关 ;其它自变量均未被选入方程。急性心肌梗死早期发生严重室性心律失常者第一天内皮素水平 (16 0 .5± 2 3.0ng/L)和QT离散度 (86± 19ms)高于未发生严重室性心律失常者 (119.7± 15 .2ng/L ,6± 13ms) ,也高于正常对照组 (45 .0± 14.7ng/L ,P <0 .0 5 ) ;此两组QT离散度与内皮素呈正相关 (r分别为 0 .94和 0 .84,P均 <0 .0 1)。

Aim To investigate the relationships between QT dispersion (QTd) and plasma endothelin (ET) levels, insulin-sensitivity, and ventricular arrhythmias in coronary heart disease (CHD). Methods Oral glucose tolerance test was conducted in 27 patients with acute myocardial infarction (AMI), 20 patients with angina pectoris and 20 healthy control subjects (in the fourth week after the onset in AMI patients). Blood samples were analysed for glucose, insulin, C-peptides and ET. Linear and/or stepwise regression analysis were used to assess the correlation between QTd and nine insulin-sensitivity parameters and ET levels. Results In patients, QTd was independently, significantly, positively correlated with ET levels. Nevertheless, fasting glucose was an independent, inversely correlated variable in AMI-recovery-period patients. The first-day ET level and QTd were higher in AMI patients with severe ventricular arrhythmias than without (160.5±23.0 ng/L Vs 119.7±15.2 ng/L,P<0.01 for ET;86±19 ms Vs 69±13 ms,P<0.05 for QTd), and both of them were higher than that in control subjects (44.98±14.74 ng/L,P<0.01). QTd was positively correlated with ET(r=0.94 and 0.84,respectively, P<0.01). Conclusions In CHD, especially in AMI, the increase of plasma ET levels is an important independent factor that causes QTd increasing and might further result in severe ventricular arrhythmias. In the recovery period of AMI, low fasting blood glucose is another independent factor of QTd increase.