速度向量成像评估正常小儿左室短轴节段心肌的旋转运动

Assessment of left ventricular rotation in normal children using velocity vector imaging

目的:通过速度向量成像(VVI)评估正常小儿左心室各节段心肌旋转运动的特征。方法:选取健康儿童50名,采集胸骨旁左室短轴心尖和心底切面的二维超声图像,脱机分析旋转角度和旋转速度、旋转角度和速度达峰时间,计算左室扭转角度,比较不同心肌节段旋转运动的差异,并分析其和年龄、心率的关系。结果:①正常小儿左室短轴的旋转运动表现为心底水平的顺时针方向和心尖水平的逆时针方向运动,心底水平的旋转角度和旋转速度从前壁到下壁逐渐递增,心尖水平的旋转角度从后间隔到侧壁依次递增,旋转速度从后间隔到后壁依次递增;②心底水平的旋转角度和旋转速度大于心尖水平的相应节段。心底水平各节段的旋转角度与年龄、心率无相关性(P>0.05)。心尖水平的后间隔旋转角度和年龄(r=0.354,P=0.012)、心率相关(r=0.401,P=0.004);③心底水平各节段的旋转角度的重复性较心尖水平各节段好(P<0.05)。结论:心底水平的旋转角度不受年龄、心率的影响,且重复性好,可更加准确地反映左室的局部心肌运动。

Objective：To assess the regional left ventricle （LV） rotational motion in normal children with velocity vector imaging （VVI）. Methods：Short-axis parasterna[ views were taken at the base and the apex of LV in 50 healthy children. Peak rotation, peak rotation velocity, time to peak rotation and time to peak rotation velocity were measured on Syngo Workplace offline. The peak twist of LV were calculated, and values of different segments were compared. Then correla- tion were analyzed with age and with heart rate. Results^O A normal LV rotation was performed with clockwise motion at the base and canterclockwise at the apex. At basal level, rotation and rotation velocity gradually increased from anterior to inferior segment. At apical level, rotation increased from inferoseptal to lateral segment whereas r6tation velocity increased from inferoseptal to inferior segment; ②Rotation and rotation velocity were higher at base than apex. Rotation in various segments of base did not correlated with age or heart rate （ P〉0.05）. Rotation in inferoseptal segment had a correlation with age （ r =0. 354, P =0. 012）and with heart rate （ r =0. 401, P =0. 004）; ③Rotation in various basal segments were of better reproducibility than apcal segments （ P d0.05）. Conclusion With good reproducibility, not affected by age and heart rate, rotation of base could be used to estimate LV regional motion accurately.