组织多普勒显像评价二尖瓣置换术后左心室功能

Assessment of left ventricular function after mitral valve replacement by tissue Doppler imaging

目的探讨应用组织多普勒显像（TDI）评价二尖瓣置换（MVR）术后左室功能的临床价值。方法45例接受MVR术后3个月以上患者为病例组，根据心律分为心房颤动组和窦性心律组，并选取30例正常人为对照组。应用常规超声心动图测量左房室腔大小、机械瓣口流速、射血分数等指标；应用TDI测量心尖四腔观二尖瓣环间隔处和侧壁处运动收缩期峰值速度（Sm）、舒张期峰值速度（Em）、等容舒张时间（IVRT）；计算E／Em。结果①与对照组相比，MVR组二尖瓣环Sm、Em均明显减低，IVRT延长（P〈0．001），但窦性心律组与心房颤动组之间差异无统计学意义（P〉0．05）；②MVR组E／Em较对照组明显增高，二者差异有统计学意义（P〈0．001），且E／Em与IVRT呈正相关；以E／Em〉15．0为最佳截断值，评价左室舒张功能变化的敏感性为91．11％，特异性为90．32％，ROC曲线下面积为0．9548±0．0402。结论TDI能够准确评价MVR后左室功能，E／Em作为一种评价心肌舒张和左室充盈压的量化指标可以评价MVR术后患者左室舒张功能。

Objective To evaluate the clinical value of tissue Doppler imaging （TDI） in assessing left ventricular（LV） function after mitral valve replacement （MVR）. Methods Forty-five patients having their implantations for more than three months were examined by echocardiography and divided into atrial fibrillation group（AF group, n = 21 ）and sinus rhythm group（SR group, n = 24）. Thirty normal volunteers served as control group. Left atrium and ventricle indexs of cardiac function and mitral inflow velocity（E）were measured by twodimensional and Doppler echocardiography,and TDI derived systolic mitral annular velocity（Sin）, diastolic mitral annular velocity（Era） and isovolumic relaxation time（IVRT）were measured at the septal and lateral corners of mitral annulus from the apical four-chamber view. Then E/Era ratio was calculated. Results ①Compared with control group,Sin and Em in MVR group were significantly lower and IVRT was higher（ P 〈0. 001 ）, however there were no significant differences between AF group and SR group. ②The E/Era ratio in MVR group was significantly higher than that in control group （ P 〈0. 001 ） and positively correlated with IVRT. The best cutoff value for E/Era ratio was increased of 15 which yielded the sensitivity and specificity in predicting LV diastolic dysfunction were 91.11% and 90.32%, respectively. The area under the ROC curve was 0.9548 ± 0.0402. Conclusions TDI-derived indexes（Sin, Era）can assess LV function accurately and the E/Era ratio, an estimate of myocardial relaxation and LV filling pressures,can be used to evaluate left ventricular diastolic function after MVR.