左心室射血分数与缩短分数对冠状动脉旁路移植术后室性心律失常的预测

Value of Left Ventricular Ejection Fraction and Fractional Shortening to Predict Ventricular Arrhythmia after Coronary Artery Bypass Grafting

目的 研究冠状动脉旁路移植术 (CABG)前左心室射血分数 (EF)和左心室缩短分数 (FS)对术后室性心律失常 (VA)预测的准确性。 方法 回顾性分析我院 1998～ 1999年度 CABG患者 30 0例 ,手术前、后定期用彩色超声心动图测 EF和 FS值 (面积长轴法 ) ,信号平均心电图测心室晚电位 (VL P) ,围术期监测心肌酶确定心肌缺血和围手术期心肌梗死 ,2 4小时 Holter及持续心电监测心律。 结果 术前心肌梗死、室壁瘤、VA和 VL P阳性者术后 EF、FS值明显减低 ,左心功能不全者 (L VD)术后 EF、FS值明显改善 ,L VD、VA、VL P阳性和室壁瘤患者术后 VA发生率明显高于其他患者。 结论 EF和 FS值是反映左心室收缩功能的敏感指标 ,FS较 EF更能准确地反映心脏收缩功能 ;术前 L VD者术后短期左心功能明显好转 ,获益最大 ,所以 L VD不应作为 CABG术的绝对禁忌证 ,相反是手术的相对适应证 ;EF≤ 0 .40和 /或 FS≤ 0 .2 4是预测术后 VA的独立指标 ;综合 L VD、VL P和室壁瘤等指标分析有助于提高对术后预测 VA的敏感度、特异度和准确度。

Objective To evaluate the accuracy of left ventricular ejection fraction(EF) and fractional shortening(FS) for predicting ventricular arrhythmias(VA) after coronary artery bypass grafting(CABG). Methods Between 1998 and 1999, retrospective study of three hundred consecutive patients undergoing isolated CABG was performed. The parameters of EF, FS were measured to assess myocardial function by echocardiography, signal averaged electrocardiogram, measuring ventricular late potential (VLP), 24-hour Holter monitoring electrocardiogram, and serum cardiac enzymes levels were monitored to identify myocardial ischemia and peri-operative myocardial infarction (MI). Results Patients with previous MI, aneurysm, VLP+ and VA had obviously lower EF and FS before CABG than those without them; In patients with LVD , significant improvement was found in EF and FS indexes after myocardial revascularization and aneurysmectomy; The incidence of postoperative VA is higher in these patients with LVD,VA,VLP+ and aneurysm than the others. Conclusion EF and FS are sensitive indexes in reflecting left ventricular function; CABG and aneurysmectomy not only improve the myocardial blood supply, but also increased the cardiac out-put in patients with LVD in short-term follow-up(14±1d);EF≤0.40 and/or FS≤0.24 are independent predictors for the prevision of VA after CABG; Integrating with other indexes ,such as VLP , aneurysm and so on, the sensitivity, specificity and accuracy for predicting post-operational VA could be obviously improved.