组织多普勒成像监测冠状动脉旁路移植术患者左心室功能的可行性

Feasibility of estimating left ventricular function by intraoperative tissue Doppler imaging in patients undergoing coronary artery bypass grafting

目的 采用组织多普勒成像（TDI）技术监测冠状动脉旁路移植前、后左心室前壁心肌组织功能的变化，评价TDI术中监测左心室功能的可行性。方法 随机连续选择左前降支冠状动脉旁路移植术患者40例，采用TEE探头在胃底左心室短轴切面取左心室前壁中层行TDI采样，记录收缩速度（Vs）、舒张早期速度（Ve）、舒张晚期速度（Vc），并计算V3／Vs；采用TEE二维超声行左室室壁运动视觉评分，测量左心室射血分数（EF）、左心室充盈早期血流速度（E）、晚期速度（A）频谱，并计算E／A；通过肺动脉导管记录心输出量（CO）、肺毛细血管楔压（PCWP）和中心静脉压（CVP）。将TDI技术测定的左心室功能参数分别与TEE二维超声和肺动脉导管测定的参数进行直线相关分析。结果 所有患者均可获得满意的左心室前壁中层TDI频谱；冠状动脉旁路移植后左心室前壁Vs、Ve、Va较移植前增加（P〈0．05），Ve／Va无明显变化（P〉0．05）；移植后室壁运动视觉评分改善，EF增加（P〈0．05），二尖瓣频谱显示A波增加（P〈0．05），E波无明显变化，E／A下降（P〈0．01）；移植后CO及心指数（CI）增加（P〈0．01）。直线相关分析显示左室前壁Vs与CO、CI无相关关系，Ve／Va与CVP、PCWP和二尖瓣血流E／A在移植前、后均无相关关系。TDI未提示患者出现新的心肌缺血证据。结论 左心室前壁TDI能定量测定冠状动脉旁路移植前、后局部心肌组织功能的变化，但不能反映左心室整体功能的变化。

Objective To evaluate the regional and global cardiac function before and after coronary artery bypass grafting （CABG） and the feasibility of estimating left ventricular function by intraoperative tissue Doppler imaging （TDI）. Methods Forty consecutive patients undergoing CABG of anterior descending branch of left coronary artery were studied. Peak myocardial velocity （Vs）, early diastolic velocity （Ve ） and late diastolic velocity （Va） of the anterior mid-wall of the left ventricle were measured by transesophageal echocardiography （TEE） and pulsed-wave TDI in addition to transmitral flow velocity. Cardiac output （CO）, PCWP and CVP were measured with pulmonary artery catheter. Correlation between parameters obtained through pulmonary artery catheter （PAC） and TDI measurements was analyzed. Results Hemodynamic parameters and visual assessment were improved after revascularization. Vs increased from （5.0 ±1.1 ） cm·s^-1 before CABG to （5.9 ± 1.5） cm·s^-1 after revascularization; Ve from （5.2± 1.5） cm·s^-1 to （6.1±2.4） cm·s^-1 and V, from （5.8± 1.4） cm·s^-1 to （6.6 ±1.8） cm·s^-1 but Ve/Va ratio did not change significantly. No TDI changes indicating new myocardial ischemia were seen in any patient. Conclusion Intraoperative measurement of TDI of the anterior wall of left ventricle provides additional quantitative information on regional systolic and diastolic function but can not estimate the changes in the global function of left ventricle.