摘要目的 探讨二维斑点追踪技术(2D-STI)评价正常人左心房收缩功能和同步性的可行性.方法 应用2D-STI测量32例健康受试者左心房主动收缩时各房壁(前壁、下壁、后壁、侧壁、房间隔)三节段(基底段、中段、上段)的峰值速度、纵向收缩峰值幅度、径向收缩峰值幅度、纵向应变达峰时间、径向应变达峰时间.结果 ①左心房收缩时,各房壁间相同水平节段的收缩峰值速度、幅度(纵向和径向)和达峰时间(纵向和径向)差异均无统计学意义(P＞0.05).②左心房各房壁自身各节段间收缩峰值速度、纵向和径向收缩峰值幅度从基底段到上段递减,除前壁、后壁和房间隔的径向收缩峰值幅度(P分别为0.218,0.258和0.238)外,差异有统计学意义(P＜0.05).③各房壁自身各节段间比较,除后壁纵向应变达峰时间(P=0.002)和侧壁径向应变达峰时间(P=0.026)外,应变达峰时间差异无统计学意义(P＞0.05).④纵向和径向收缩整体达峰时间的标准差分别为37.38 ms、48.25 ms,两个方向运动作为一个整体,其标准差约43.85 ms.各房壁同一节段的纵向和径向应变达峰时间没有明显的相关性(r=0.014,P=0.885).结论 左心房收缩时房壁运动具有一定的规律性,总体表现为各房壁收缩峰值速度和幅度从基底段到上段递减的特性,各房壁间相同节段运动达峰时间基本同步.2D-STI可以较准确地评价正常人左心房收缩功能和同步性.

abstractsObjective To evaluate left atrial systolic function and synchronization by two dimensional speckle tracking imaging(2D-STI) measuring the strain in healthy subjects.Methods Thirty-two healthy subjects were studied.The peak velocity(Vmax),the peak amplitude of longitudinal and radial strain (Am-LS and Am-RS),the peak time of both longitudinal and radial strain(T-LS and T-RS) were acquired in each left atrial wall(anterior,inferior,posterior,lateral and septal) at three levels (basal,middle and apical)during left atrial active contraction by 2D-STI.Results ① No significant differences were found at theVmax,Am-LS,Am-RS,T-LS and T-RS among all left atrial walls in the same level ( P ＞ 0.05).②The Vmax,Am-LS and Am-RS were decreased progressively from basal to apical,and there were significant differences( P ＜0.05) except the Am-RS at anterior,posterior and septal( P =0.218,0.258 and 0.238,separately).③Compared all levels in each left atrial wall,the T-LS and T-RS showed no significant differences( P ＞0.05),except the T-LS at posterior( P =0.002) and the T-RS at lateral( P =0.026).④The standard deviation of the T-LS,T-RS and T-globe were 37.38 ms,48.25 ms and 43.85 ms,respectively.There were no significant correlation between T-LS and T-RS in the same segment with r =0.014 and P =0.885.Conclusions There were some regularity during left atrial active contraction.On the whole,the peak velocity and the peak amplitude were decreased progressively from basal to apical in each atrial wall,and the peak time of strain showed no significant difference in the same level of each left atrial wall.The 2D-STI may paly important roles in the evaluation of left atrial systolic function and synchronization.