β-受体阻滞剂对不同病因所致心力衰竭的QT离散度的影响

Randomized control study on effects of β-blocker on QT dispersion in patients with heart failure clue to different causes

目的 :探讨β1 -受体阻滞剂比索洛尔对慢性充血性心力衰竭 (CHF)患者的 QT离散度 (QTd)的影响 ,并比较比索洛尔对不同基础心脏病 CHF QTd影响的差别。方法 :81例 CHF患者按病因分层后随机分为比索洛尔治疗组与对照组 ,测定两组治疗前后的 QTd,同时比较治疗组间及不同病因组间的 QTd变化的差异。结果 :比索洛尔组能显著降低 CHF患者的 QTd(P <0 .0 1) ,对照组治疗前后 QTd无显著变化 (P >0 .0 5 )。缺血性心脏病患者 QTd降低较扩张型心肌病患者明显 (回归系数 β=- 0 .2 83,P <0 .0 5 )。结论 :β-受体阻滞剂对心力衰竭患者 QTd有改善作用 ,而且缺血性心脏病对 β-受体阻滞剂的反应较扩张型心肌病好。提示 QTd可以作为预测 β-受体阻滞剂治疗 CHF远期疗效的替代终点指标。

Objective:To evaluate the effect of β 1 selective blocker bisoprolol on the QT dispersion in patients with chronic heart failure and to compare the responses to bisoprolol in patients with different etiologies. Method:81 patients with heart failure secondary to ischemic heart disease (n=47) or idiopathic dilated cardiomyopathy (n=34) were stratified by etiology and then randomly assigned to the bisoprolol and blank control group on the top of the conventional treatment. QT dispersion was calculated by subtracting the shortest QT from the longest QT, in absolute value (Qtmax Qtmin). Result:After 6 weeks treatment, QT dispersion were significantly decreased in the bisoprolol group (P< 0.01 ) , but there was no significant decrease of QT dispersion in control group. Linear regression analysis showed that patients with ischemic heart disease tend to have lower 6-week QT dispersion than patients with dilated cardiomyopathy (coefficient = -0.283 , P= 0.009 ) after controlling for their baseline values in the bisoprolol group. Conclusion:This paper finds that bisoprolol reduce QT dispersion in patients with chronic heart failure,and patrents with iachemic heact disease respond to bisoprolol better than those patients with idiopathetic dilated carsdiomyopathy.It suggets that QTd may be a predictor as an end point for treating CHF with β receptor.