二尖瓣环不同部位组织多普勒波形对评价左心室舒张功能的影响

Effects of mitral annulus sites on the Doppler tissue imaging waves in assessment for diastolic function of the left ventricle

目的了解二尖瓣环的部位不同对组织多普勒(TDI)测量结果及衍生指标评价左心室舒张功能的影响。方法 182例接受常规超声心动图检查者,于心尖四腔切面测量二尖瓣口舒张期血流频谱,于心尖四腔、两腔及左心三腔切面分别测量二尖瓣环室间隔、左心室侧壁、前间隔、后壁、前壁及下壁6个位点的TDI舒张期波形,计算二尖瓣口舒张早期血流E峰与舒张晚期血流A峰的比值(MV-E/A)、TDI二尖瓣环舒张早期e波与舒张晚期a波的比值(TDI-e/a)及E峰值与二尖瓣环6个位点e波平均值与E峰的比值(E/e-mean),同步记录心电图。结果根据二尖瓣口血流波形E/A比值不同,将182例患者分成两组,组Ⅰ:二尖瓣E/A≥1.0,共76例;组Ⅱ:二尖瓣E/A<1.0,共106例;组Ⅰ中同时有4个位点e/a≥1.0的患者多于组Ⅱ(59.21%,8.49%),而组Ⅱ中二尖瓣环6个位点e/a比值均<1.0的患者明显较多(64.15%,14.47%,P<0.05);即使同一组内,任意两位点之间的E/a比值多有不同或显著差别,测值相近的位点在组Ⅰ、组Ⅱ中分别占28.57%和14.29%,其中组Ⅰ中仅有左心室后壁、下壁2个与E/a-mean相近的位点,而组Ⅱ中则没有与E/a-mean相近的位点。结论临床应用二尖瓣口舒张早期血流E峰值与二尖瓣环舒张早期e波值比(E/e-ann)与二尖瓣E/A指标评估左心室舒张功能时,需注意二尖瓣环位点不同对测定结果的影响,而取二尖瓣环6个位点E/e-mean,有助于减少此类指标在评价左心室舒张功能中的偏颇。

Objective To understand the effects of mitral annulus sites on the measurements and derived index of Doppler tissue imaging （TDI） in assessment for diastolic function of the left ventricle. Methods One hundred and eighty-two patients with sinus rhythm were recruited for routine echocardiography and synchronous electrocardiogram or assessment of left ventricular（LV） function. The early and late diastolic velocities of LV in these patients, which were composed of e and a waves, were recorded using TDI at the mitral annulus. Six sites at the mitral annuli were selected corresponding to the septal, lateral, anterior septal, posterior, inferior and anterior walls of LV from apical 4-, 3- and 2-chamber views. Transmitral diastolic flow velocity, which was represented by E and A waves, was measured by PWD from apical 4-chamber view. Ratio of early and late diastolic transmitral valve （MV-E/A）, ratio of TDI-e/a-ann and ratio of E/e-ann were calculated respectively. A mean value of e-ann from the above 6 sites was selected to assess the early diastolic velocities of mitral annular. Results According to the results of MV-E/A ratio, 182 patients were classified into 2 groups： groupⅠ： 76 patients with mean age of 45.26±14.35 years, （MV-E/A≥1.0）; groupⅡ： 106 patients with mean age of 65.55±11.52 years （MV-E/A1.0）. There were more patients with 4 or more than 4 sites of e/a≥1.0 at the mitral annuli in groupⅠ than in group Ⅱ（59.21% vs 8.49%）, while there were more patients with all the 6 sites of e/a1.0 in group Ⅱthan in groupⅠ（64.15% vs 14.47%, P0.05）. Even in one group, ratios of E/e between any two sites at the mitral annuli were often different. In the two groups, incidences of similar ratio in E/e at the 6 sites were 28.57% and 14.29% respectively,among which there were only ratios of E/e being close to the E/a-mean in group Ⅰ without any of ratios of E/e in 6 sites being similar to the E/a-mean in groupⅡ. Conclusion The effects of mitral annulus sites on the results of TDI measurements should be cautioned when E/e-ann was clinically used to assess the diastolic function of left ventricle, while screening of the mean e-ann from the 6 sites to assess the early diastolic velocities of mitral annular （E/a-mean） might improve the efficiency of this index in assessment of LV diastolic function.