超声二维斑点追踪成像技术评价尿毒症患者左心室扭转与同步性运动

目的 应用超声二维斑点追踪成像技术(STI)探讨尿毒症患者的左心室旋转及扭转运动特征,并评价心肌同步性运动.方法 尿毒症患者30例,正常对照组31例.经胸采集并存储标准左心室基底部及心尖部短轴二维图像,运用EchoPAC超声工作站进行脱机分析.计算左心室心尖部旋转角度及达峰时间、心底部旋转角度及达峰时间、左心室峰值扭转角度及达峰时间、主动脉瓣关闭时间点扭转角度、解旋率,并比较两组间各参数的差异.结果 ①尿毒症患者左心室心尖部旋转角度峰值(Prot)、峰值扭转角度(Ptw)、主动脉瓣关闭时间点扭转角度(AVCtw)及解旋率(UntwR)较正常对照组明显减低,差异均有统计学意义(P<0.001).②尿毒症患者心尖部旋转角度达峰时间、扭转角度达峰时间均明显延迟于主动脉瓣关闭时间,而心底部旋转角度达峰时间早于主动脉瓣关闭时间,差异均有统计学意义(P<0.05).③尿毒症患者Ptw与左心室射血分数(LVEF)、收缩末期容积(LVESV)、舒张末期容积(LVEDV)及心尖部旋转速度峰值(PTVap)高度相关(P<0.05).结论 STI技术可准确、无创地评价左心室旋转及扭转运动,并能从旋转运动的角度评估心肌运动的同步性.

Evaluation of left ventricular twist and dyssynchrony in uremia patients with two-dimensional ultrasound speckle tracking imaging

Objective To analyze the left ventricular (LV) rotation and twist in uremia patients with two-dimensional ultrasound speckle-tracking imaging (STI), and to evaluate LV dyssynchrony by comparison of time to peak rotation/twist. Methods Thirty uremia patients and thirty-one healthy volunteers were included. High frame rate two-dimensional images were recorded from the left ventricular short-axis views both of the basal and apical planes. LV peak rotation of apex (Prot) and time to the peak rotation were recorded at both views. LV twist was defined as apical rotation relative to the base. Peak twist (Ptw), twist at aortic valve closure (AVCtw) and untwisting rate (UntwR) were calculated. Results Compared with healthy volunteers, the peak value of apical rotation, Ptw, AVCtw and UntwR decreased significantly in uremia patients (P<0.001). Time to the maximal apical rotation and time to peak twist significantly delayed into the isovolumic relation period, while time to maximal basal rotation occurred earlier than aortic valve closure (AVC) timing (P<0.05). Significant correlations were noted between systolic peak twist and LVEF (r=0.823, P<0.001), LV end-diastolic volume (r=-0.559, P=0.001), LV end-systolic volume (r=-0.747, P<0.001) and apical rotation velocity (r=0.602, P<0.001) in uremia patients. Conclusion STI can measure the LV rotation and twist noninvasively, providing a new way for evaluating the LV function and dyssynchrony in uremia patients.