中文摘要：

目的观察健康比格犬左室心肌三维峰值位移（3D-D）、径向位移（RD）、纵向位移（LD）变化，量化评价健康比格犬左室心肌位移的力学变化特征，探讨心肌位移参数的临床应用价值。方法10只健康比格犬开胸模型，分别采集一个完整心动周期的实时全容积灰阶图像，应用斑点追踪成像技术测量左室心肌整体和各节段319-D、RD和LD的峰值变化，分析3D-D、RD和LD之间的差异性及相关性。结果结果①左室心肌各节段3D-D与RD之间比较差异无统计学意义（P〉0．05）；左室心肌各节段3D-D与LD之间比较差异具有显著统计学意义（P〈0．01）；左室心肌各节段RD与LD之间比较差异具有显著统计学意义（P〈0．01），左室心肌各节段LD小于3D-D和RD，差异具有显著统计学意义（P〈0．01）。②左室心肌整体3D-D与RD之间比较差异无统计学意义（P〉0．05）；左室心肌整体3D-D与LD之间比较差异具有显著统计学意义（P〈0．01）；左室心肌整体RD与LD之间比较差异具有显著统计学意义（P〈0．01）；左室心肌整体LD小于3D-D和RD，差异具有显著统计学意义（P〈0．01）。③左室心肌大多数节段3D-D与RD具有显著相关性（P〈0．01），仅中侧壁和尖侧壁具有相关性（P〈0．05）；左室心肌3D-D与LD相关性分析，仅底前间隔、底下壁、中前壁、中前间隔、尖下壁、尖侧壁具有相关性（P〈0．05），其余节段之间不具有相关性（P〉0．05）；左室心肌RD与LD相关性分析，仅底前间隔、底下壁、中前壁、尖间隔、尖下壁、尖侧壁具有相关性（P〈0．05），其余节段之间不具有相关性（P〉0．05）。结论左室心肌3D-D与RD比较无明显差异同时密切相关，3D-D能够准确反映左室心肌实际的运动轨迹，RD是左室三维结构形变和力学变化的主要表现形式，RD比LD更能反映左室心肌的有效运动。

英文摘要：

Objective To evaluate the changes of left ventricular myocardial peak 3-dimensional displacement（3D-D）, radial displacement（RD） and longitudinal displacement（LD） during baseline patterns, and provide a reliable and appropriate mechanical database for myocardial structure and function. Methods Left ventricular 3D full volumetric real-time imaging in open-chest Beagle canine models（ n = 10） were acquired in a complete cardiac cycle. The 3D-D, RD and LD for differences and rules were calculated and analyzed by speckle tracking imaging. Results （1） There were not difference between 3D-D and RD at baseline patterns with all segments（ P 〉0.05）. There were significant difference between 3D-D and LD at baseline patterns with all segments （ P 〈0.01）. There were significant difference between LD and RD at baseline patterns with all segments （ P 〈 0.01）. 0 There were not difference between 3D-D and RD at baseline patterns with the global（ P 〉0.05）. There were significant difference between 3D-D and LD at baseline patterns with the global （ P 〈 0.01 ）. There were significant difference between LD and RD at baseline patterns with the global（ P 〈0.01）. （3） There were significant correlation between 3D-D and the most segments of RD（ P 〈0.01）. There were correlation between 3D-D and the partly segments of LD （P 〈 0.05）. There were correlation between the partly segments of RD and I.D（ P 〈0.05）. Conclusions Echocardiographic study of left ventrieular 3D-D can actually reveal myocardial mechanics and strcture during baseline patterns. 3D-D can accurately reflect left ventrleular motion condition. The changes of myocardial mechanics mainly depends on the radial motion. Left ventricular RD can be more accurately reflection on myocardial motion state than LD.