术中组织多普勒成像在左心功能监测中的作用

【作者】 王伟鹏；

【导师】 李立环；

【作者基本信息】 中国协和医科大学 ， 麻醉学， 2007， 博士

【副题名】心肌组织运动、血流、心功能及压力相关关系的研究

【摘要】 背景：左室功能是预测心脏病患者转归的重要指标，早期发现和及时处理对患者的转归和预后有明显影响。组织超声多普勒成像（tissue Doppler imaging，TDI），是一项新的无创定量心肌运动分析技术，可显示心肌收缩、舒张运动频谱，评价心脏功能，它在术中与肺动脉导管监测的心功能及血流动力学参数相关关系尚未见报道，有必要利用经食管超声心动图（TEE）评价TDI在心功能和血流动力学作用。目的：探索IDT在心脏不同部位的频谱特征及采样成功率；分析TDI参数与肺动脉导管参数的相关性；评价TDI参数在心功能评价中的作用。方法：冠状动脉旁路移植术患者40例，平均年龄63±7.8岁，窦性心律。同时进行TEE和肺动脉导管监测。肺动脉导管可持续监测心输出量（CO），中心静脉压（CVP）和肺毛细血管嵌压（PCWP）。用TEE测量和评估患者射血分数（EF），分别采集常规的二尖瓣（E、A）、左上肺静脉血流频谱（S、D）和TDI频谱（Sa，Ea，Aa），同时记录肺动脉导管参数，分别将EF、TDI的心肌收缩速度Sa与CO，血流、TDI频谱参数与PCWP进行相关分析；另外，将患者按照心功能指标CI分组，对上述参数再进行相关分析，探讨TDI参数对不同心功能患者的评价作用；对相关良好的参数做出ROC曲线，进行比较找出TDI评价心功能的最佳参数。结果：1．TEE采集心肌TDI频谱可显示心动周期内心肌收缩，舒张运动的方向、速度等信息，术中常用的采样点中，二尖瓣环室间隔和左室前、下壁采样成功率为（100％），二尖瓣环侧壁采样成功率相对较低（95％）；采集二尖瓣血流频谱成功率100％；左上肺静脉成功率为85％。2．心功能较好患者二尖瓣环收缩速度S_侧壁、S_间隔显著大于心功能较差的患者，S_间隔、S_侧壁与CO相关良好（r分别为0.606及0.438，P＜0.01）；S_间隔与CO在心功能较差的患者有良好相关性（r=0.653，P＜0.01）；目测EF及测量EF均与CO有良好的相关良好（r分别为0.626，0.627，P＜0.01）。3血流频谱：二尖瓣瓣口血流速度E／A比值与PCWP相关分析中，心功能较差的患者（（r=0.621，P＜0.01））比整体（r=0.377，P＜0.05）和心功能正常患者相关性好，肺静脉血流频谱与PCWP未发现相关关系TDI频谱中：二尖瓣环舒张早期与晚期速度比Ea／Aa_间隔（r=—0.635，P＜0.01）、Ea／Aa_侧壁（r=-670，P＜0.01）与PCWP呈反相关且相关良好，其中Ea／Aa_间隔与PCWP相关性在不同心功能的患者（r分别为-0.802和-0.745）均有稳定的相关关系；结合参数：舒张早期二尖瓣血流速度与二尖瓣环运动速度比值E／Ea_间隔（r=0.699，P＜0.01）、E／Ea_平均（r=0.685，P＜0.01）、E／Ea_侧壁（r=0.681，P＜0.01）与PCWP呈正相关且相关良好，其中E／Ea_间隔（r分别为0.681 vs 0.738）和E／Ea_平均（r分别为0.760 vs 0.527，）在不同心功能患者与PCWP均有良好的相关关系，其余各参数均与PCWP无相关关系；对有相关性参数以PCWP＞12mmHg为标准做ROC曲线分析：在综合比较各相关参数ROC曲线下面积可见E／Ea_间隔的曲线下面积＞Ea／Aa_间隔曲线下面积＞其他参数，血流频谱E／A比值得95％CI包含0.5，不能预测PCWP。确定E／Ea_间隔截断点为l4时，E／Ea_间隔预测PCWP＞12mmHg的敏感性为83.33-92.31％，特异性为71.43-87.50％；Ea／Aa_间隔截断点为0.95时，Ea／Aa_间隔预测PCWP＞12mmHg的敏感性60.00-69.23％，特异性为57.14-87.50％。结论：1 TDI（?）采集心肌TDI频谱可显示心动周期内的心肌收缩，舒张运动的方向、速度等信息，术中常用的采样点中，二尖瓣环室间隔和左室前壁采样成功率高（100％），二尖瓣环侧壁采样成功率相对较低（95％）；采集二尖瓣血流频谱成功率较高（100％）；左上肺静脉血流频谱成功率相对较低（85％）。2术中TEE测量和目测EF可以快速准确地评价左室收缩功能；二尖瓣环间隔、侧壁心肌收缩速度，特别是间隔侧可反映左室收缩功能；左室前、后壁心肌收缩速度不能反映左室收缩功能。3二尖瓣口血流频谱虽然与PCWP有相关关系，但并不能预测PCWP的升高，TDI频谱中血流速度和组织运动结合参数E／Ea_间隔预测左室舒张功能最好，其次为TDI参数Ea／Aa_间隔。更多还原

【Abstract】 Background: Cardiac function is good predictor of outcome for cardiac surgery patients. Fast assessment and early intervention of left ventricular (LV) function provides an important information on the hemodynamic status and benefits the outcome and prognosis in the cardiac surgery patients. TDI(tissue Doppler imaging) is a new noninvasive technology of assessing movement of myocardium, which is used for evaluation of the cardiac function. However, there is no literatures on correlation between the TDI variables and pulmonary arterial catheter parameters(PAC) reported in cardiac surgery patients. This study is designed to analysis the relationship between the TDI variables and PAC parameters.Objects: This study was to investigate the success rate of TDI and conventional Doppler sampling at different site of heart; to assess whether mitral annular velocities as measured by TDI are associated with invasive measures of PAC parameters and whether additional information is gained over traditional Doppler variables; to investigate the reliability of TDI in estimating left ventricular filling pressure.Methods: We prospectively studied 40 patients, mean age 63±7.8 years, in sinus rhythm. All patients underwent CABG. Transesophageal echocardiography (TEE), pulmonary artery catheterization (PAC) and other hemodynamic monitoring were performed at the same time. PAC investigated continuous cardiac output (CCO), central venous pressure(CVP) and pulmonary capillary wedged pressure(PCWP). TEE-LVEF was calculated using M-mode analysis and vision assessment of wall motion of LV wall. The following Doppler parameters were assessed: PW Doppler signals from the mitral inflow (E, A), PW TDI of the mitral annulus (Sa, Ea, Aa), thus allowing to obtain the mitral inflow to annulus ratio (E/Ea). Correlations were analyzed between EFs、Sa and CO, and between the TDI parameters and PCWP. Then according to the CI＞2.0, patients were divided into 2 subgroups. Correlations were re-analyzed in the subgroups to identify the differences between two groups. ROC analysis was done for the correlated variables to identify the best parameter and cut-off value to predict elevation of PCWP.Results: 1 TDI spectrums could be obtained from septal annulus, lateral annulus, anterior wall and posterior wall of left ventricle. The success rate of sampling from septal annulus, anterior and posterior wall is 100%, while the lateral annulus is 95%(2 cases unsuccessful). Mitral signal is more easly got with success rate of 100% than pulmonary venous signals with success rate of 85%.2. For the systolic function, both annulus contraction velocity in septal and lateral wall are significantly higher(4.7±0.8, and 6.2±2.2) in normal function group than that(3.8±0.763.8±0.76 and 4.5±1.0) in abnormal group(P＜0.05); Septal and lateral contraction velocity correlated well with CO (r=0.606 and 0.438 respectively), and septal contraction velocity correlated with CO in abnormal group(r=0.653, P＜0.01). Both EFs investigated by calculation(r=0.627, P＜0.01) and vision assessment(r=0.626, P＜0.01) correlate well with CO as well.3. Diastolic function: Although transmitral E/A ratio showed a better correlation with PCWP in abnormal group than that in whole patients, ROC analysis showed that it could not predict the PCWP elevation because 0.5 was included in 95% CI. Pulmonary venous velocity curves were not found have close relationship with PCWP in this study. For TDI of mitral annulus movements, early and late velocity ratio(Ea/Aa) at septal and lateral wall show an inverse correlation with PCWP(r=-0.635, and -0.670 respectively). Septal annulus Ea/Aa has a constant relationship with both normal and abnormal group(r=-0.635 and -0.670 repectively). The ratio of mitral velocity to early diastolic velocity of septal mitral annulus E/Ea(r=0.699, P＜0.01), mean E/Ea(r=0.685, P＜0.01)、lateral E/Ea (r=0.681, P＜0.01) ) showed a correlation with PCWP, and septal E/Ea间隔(r=0.681vs 0.738), mean E/Ea (r=0.760 vs 0.527,) had better correlation than did other Doppler variables for all levels of systolic function. The ROC analysis was repeated with PCWP＞12 mm Hg used as the definition of elevated filling pressure. The areas under the respective ROC curves were 0.905(septal E/Ea), 0.764(setal Ea/Aa), 0.732 (mean E/Ea ratio).As with the cutoff value of E/Ea＞14 mm Hg, the septal E/Ea and lateral Ea/Aa had the best ROC curve and was the most readily obtained. Septal E/Ea＞14 had 83.33-92.31% sensitivity and 71.43-87.50% specificity for prediction of elevated PCWP. As with cutoff value of septal Ea/Aa＜0.95, Ea/Aa had 60.00-69.23% sensitivity and 57.14-87.50% specificity.Conclusions: 1. High quality of TDI of mitral annulus, anterior and posterior left ventricle can be obtained with TEE. The success rate of sampling is higher at septal annulus, anterior and posterior of left ventricle than that at lateral site. Mitral flow velocity is much easier to get than pulmonary venous flow velocity.2. EFs accessed by calculation and visual estimation are fast and accurate method to evaluate the systolic function. Septal and lateral annulus systolic velocity had a close relationship with the systolic function while anterior and posterior wall systolic velocity did not have.3. Diastolic function: Although mitral flow velocity ratio(E/A) correlated with PCWP, it can not predict the elevated PCWP; The combination of TDI of the septal mitral annulus and mitral inflow velocity curves and septal annulus early and late velocity ratio provide better estimates of LV filling pressures than other parameters.更多还原