急性肺血栓栓塞症患者右室长轴应变及应变率变化的初步研究

目的:观察急性肺血栓栓塞症(APTE)患者右室压力负荷增加后右室长轴应变、应变率变化特点,并寻找可能判断右心功能不全的有效参数。方法:采集21例APTE患者及30例健康自愿者心尖四腔切面的二维图像,在组织速度显像(TV I)模式下应用应变、应变率成像技术测量右室游离壁及室间隔的基底段、中间段、心尖段心内膜下心肌收缩期峰值应变、应变率,进行分析研究。结果:APTE患者肺动脉压中度增高后,右室游离壁及室间隔基底段、中间段收缩期应变和应变率代偿性增强,左室收缩功能变化不大,而舒张功能轻度减低;APTE患者肺动脉压重度增高后,右室各节段收缩期应变和应变率较对照组均明显减小,以右室游离壁中间段变化最为明显,同时左室、右室收缩功能均减低。以右室游离壁中间段作为代表节段,以收缩期应变小于-15%,应变率小于-1.2-s 1作为APTE时右心功能可能失代偿的参考指标。结论:应变、应变率技术是评价急性肺血栓栓塞症患者右室收缩功能变化的一种敏感、有效的方法。

A preliminary study of right ventricular long-axis strain and strain-rate changes in patients with acute pulmonary thromboembolism

Objective:To observe the changes of right ventricular long-axis strain and strain-rate in patients with acute pulmonary thromboembolism,and search possibly useful parameters to judge right ventricular dysfunction.Methods:Tissue 2D images of 30 normal control subjects and 21 patients with acute pulmonary thromboembolism from the apical 4-chamber view.In quantitative tissue velocity imaging pattern,peak systolic strains,peak systolicst strain rates at the basal,mid and apical segment of right ventricle free wall and septal were quantitatively measured by using strain rate imaging and strain imaging software system,and then analysis.Results:The moderate group could result in the increased systolic strain and strain rate of right ventricle reactively,as well as the decreased diastolic fuction of left ventricle.The severe group could result in the significantly decreased srain and strain rate from basal、mid to apical segment,and the middle segment of right ventricle free wall was most significant among them.Also the systolic function of left ventricle and right ventricle were impaired.As strain and strain-rate in middle segment of right ventricle freewall was represented,which exceeded-15% and-1.2 s-1 respectively,were useful parameters to judge acute right heart failure.Conclusion:Strain rate imaging and strain imaging provide a sensitive and reliable approach for the assessment of right ventricular function in patients with acute pulmonary thromboembolism.