组织多普勒显像评价二尖瓣置换术后左心室功能

摘要

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 two dimensional and Doppler echocardiography,and TDI-derived systolic mitral annular velocity(Sm),diastolic mitral annular velocity(Em)and isovolumic relaxation time(IVRT)were measured at the septal and lateral corners of mitral annulus from the apical four-chamber view.Then E/Em ratio was calculated.Results ①Compared with control group,Sm 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.② The E/Em 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/Em 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-defived indexes(Sm,Em)can assess LV function accurately and the E/Em ratio,an estimate of myocardial relaxation and LV filling pressures,can be used to evaluate left ventricular diastolic function after MVR.%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.