组织速度成像评价正常人心动周期时间间期的研究

目的根据组织速度图中速度-时间曲线确定心脏心动周期的时间间期及其正常参考值。方法获取29例健康志愿者标准心尖二腔、心尖长轴和心尖四腔观组织速度图,根据心肌各节段的速度曲线,测量左、右心室各室壁基底段和中段收缩期与舒张期的时间间期。结果组织速度图在各室壁的基底段进行采样和分析,其成功率为100%。对左室室间隔基底段与右室游离壁基底段各时间间期进行配对t检验,显示两者在等容收缩时间、加速收缩时间、收缩达峰时间、等容舒张时间、R波至快速充盈峰值时间、快速充盈时间、心房收缩时间、舒张后期时间、快速充盈加速时间、心房加速时间和舒张早期达峰时间差异均存在显著或极显著性意义(P<0.05或<0.001)。对左室不同室壁的基底段与室间隔基底段的收缩期或舒张期时间间期进行配对t检验分析显示:各收缩时间间期差异均无显著性意义,而左室侧壁与室间隔基底段在快速充盈时间、等容舒张时间、舒张后期时间和R波至心房收缩峰值时间差异均存在极显著性意义。结论组织速度图不仅可以更为精确、直观、定量评价正常人心脏心动周期的时间间期,而且可以定量测量等容收缩时间、等容舒张时间、收缩加速时间和减速时间、舒张加速时间和舒张加速时间等,是一种比心电图更为全面和准确,而且可以快速、实时评价心脏时间间期的可靠方法。

Assessment of cardiac intervals with tissue velocity imaging in normal subjects

Objective To quantitatively assess cardiac intervals with tissue Doppler imaging(TDI) and normal reference values. Methods Apical 4 chamber, 2 chamber and long axis views of two-dimensional TDI were acquired in 29 healthy individuals(using GE Vivid 7 commercially ultrasound machine). The basal and middle segments in left ventricle(anterior septal, anterior, lateral, posterior, inferior and septal wall) and in the free wall of right ventricle were analyzed with tissue velocity imaging(TVI) model.Cardiac intervals of each segment, which included the isovolumic contraction time, contraction to peak time, insovolumetric relaxation time, rapid filling time and artrial contraction time were measured using TVI in the left ventricle and free wall of the right ventricle. Results The successful rate of sample was 100% in basal segment of each wall. There were significant differences between the left and right ventricle in the isovolumetric contraction time, the systolic accelaration time, contraction to peak time, isovolumetric relaxation time, early diastolic time, diastasis and artrial contraction( P < 0.05 or < 0.01). There was no significant difference in the cardiac systolic intervals in all of the walls, but there were significantly differences in rapid filling time, isovolumetric relaxation time, diastasis and the time of R wave to peak for artrial contraction between the septal and lateral walls, which was statistically made in paired-samples t test. Conclusions Cardiac intervals can not only be evaluated with TVI in the left ventricle, but in the right ventricle, which is a new and reliable quantitative method of cardiac intervals.