术中多巴酚丁胺负荷经食道超声心动图预测冠状动脉旁路移植术后心肌存活的评价

Prediction of myocardial viability after coronary revascularization by intraoperative dobutamine stress transesophageal echocardiography

目的 评价术中多巴酚丁胺负荷经食道超声心动图（DSE）预测冠状动脉旁路移植术后心肌存活情况。方法择期拟行冠状动脉旁路移植术病人24例，性别不限，年龄50～75岁，体重55～90kg，NYHA分级Ⅱ或Ⅲ级，左室射血分数30％-55％。麻醉诱导后，采用食道超声按16节段法，观察左室节段室壁运动情况，行半定量评分。静脉输注多巴酚丁胺，初始速率5μg·kg^-1·min^-1，然后以1μg·kg^-1·min^-1的速率递增，每一速率持续输注3min。将舒张末室壁厚度〉0．5cm的节段、室壁运动异常评分较给药前降低≥1分的心肌定义为存活心肌。计算DSE预测心肌运动恢复的敏感度、特异度、准确率、阳性预测率和阴性预测率。结果DSE预测心肌存活率（36．3％）低于术后心肌运动改善率（43．2％）（P〈0．05）。DSE预测心肌存活的敏感度、特异度、准确率、阳性预测率和阴性预测率分别为75．3％、92．7％、85．3％、88．4％和83．5％。结论术中DSE可有效地预测冠状动脉旁路移植术后存活心肌及功能恢复。

Objective To predict myocardial viability and recovery of regional ventricular function using intraoperative dobutamine stress transesophageal echocardiography （DSE） in patients with chronic ischemic left ventricnlar dysfunction. Methods With institutional review board approval and informed consent 24 NYHA class Ⅱ or Ⅲ patients （19 males, 5 females） aged 50-75 yr, weighing 55-90 kg undergoing elective coronary artery bypass graft （CABG） were studied. Transesophageal echocardiography was used during operation. Regional wall motion （RWM） was semi-quantitatively estimated and scored by 16 segment images as suggested by American Society of Echocardiography Committee after tracheal intubation （T1）, during dobutamine infusion （T2 ） and after revascularization （T3） （0 = wall motion is augmented, 1 = normal motion, 2,3 = slightly, severely weakened motion, 4 = no motion, 5 = reverse motion）. Viability was defined as improvement in the motion of regional wall （〉 0.5 cm thick） by ≥1 score. The accuracy, specificity, sensitivity and positive/negative prediction value （PPV, NPV） of DSE for predicting the myocardial viability after revascularization were assessed. Results The ejection fraction was （39 ±11 ） % after tracheal intubation and reached （47 ±8） % at 3 rain of dobutamine infusion and （47 ± 9）% after coronary revascularization. The predicted improvement in regional myocardial function by DSE was 36.3 % and significantly lower than the segmental recovery of myocardial function after revascularization （43.2%）. The sensitivity, specificity, accuracy, PPV and NPV of DSE in predicting myocardial viability were 75.3%, 92.7%, 85.3%, 88.4% and 83.5% respectively. Conclusion Intraoperative DSE is effective in assessing the recovery of regional myocardial function after CABG.