三维斑点追踪显像分析左心室收缩功能及同步性的初步研究

目的 应用三维斑点追踪显像(3D STI)分析扩张型心肌病(DCM)合并完全性左束支传导阻滞(CLBBB)患者左心室功能及左心室同步性.方法 分别对37例DCM合并CLBBB患者及25例正常对照者进行3D STI分析,计算左心室射血分数(LVEF),16节段3D应变及经心动周期标化的达峰时间标准差(3D-SDI),左心室整体3D、长轴、短轴及圆周应变.结果 对照组心尖水平、二尖瓣水平及乳头肌水平3D应变值差异无统计学意义(P＞0.05).左心室整体3D、长轴及短轴应变与LVEF间有良好的负相关(r分别为-0.92,-0.84及-0.78,P均＜0.01),圆周应变与LVEF间有良好的正相关(r =0.81,P＜0.01).与对照组比较,病例组3D、长轴、短轴及圆周应变均明显下降(P均＜0.01),16节段3D-SDI明显增大(P ＜0.01).左心室收缩功能轻度下降、中度下降及显著下降组之间3D-SDI差异具有统计学意义(P ＜0.05),而QRS时限无显著差异.结论 3D STI测得的左心室3D、长轴、短轴及圆周应变以及3D-SDI可以准确有效地评估左心室整体、局部收缩功能及左心室同步性.

Evaluation of left ventricular function and dyssynchrony using three-dimensional speckle tracking echocardiography

Objective To evaluate left ventricular (LV) function and dyssynchrony in patients with dilated cardiomyopathy (DCM) and complete left bundle branch block (CLBBB) by three-dimensional speckle tracking imaging(3D STI).Methods 3D STI was performed and analyzed using TomTec 4-D LV analysis 3.0 software in 37 DCM patients with CLBBB and 25 healthy volunteers.The global 3D,longitudinal,circumferential,radial strains were measured.LV dyssynchrony was evaluated by the standard deviation of time to peak from 3D strain of 16 segments related to the heart cycle(3D-SDI).Results In control group,uniformity in the average value of 3D strain was observed between apical,mid-ventricular and basal levels (P ＞ 0.05).Global 3D,longitudinal,radial and circumferential strains had excellent correlations with LV ejection fraction ( r =- 0.92,- 0.84,- 0.78 and 0.81,respectively,P ＜0.01).Compared with control group,global 3D,longitudinal,radial and circumferential strains were significantly lower in DCM patients ( P ＜0.01 for all).3D-SDI in DCM patients with CLBBB was significantly longer than that of volunteers ( P ＜0.01).3D-SDI increased with worsening LV systolic function regardless of QRS duration (P ＜0.05).Conclusions When image quality is optimal,3D STI represents a promising novel technique for assessment of global LV function and dyssynchrony.