左室心尖、心底旋转绝对值之和的关系

Relationship between apical and basal rotations of left ventricle in absolute value sums

目的探讨收缩期左室心尖旋转绝对值之和与心底旋转绝对值之和的关系。方法14只杂种犬,用加热的方法破坏心尖部心肌使心尖旋转发生改变,根据加热时间不同分为心尖部心肌厚度的外1/2及3/4心肌被完全破坏两种情况,用组织多普勒超声分别检测这两种情况的心尖及心底旋转速度。提取心肌运动速度数据,根据速度时间积分公式并经计算机编程计算心尖及心底旋转,并以收缩期旋转的绝对值之和作为分析参数,分别比较两种情况下心尖及心底旋转绝对值之和的变化。结果心尖部心肌厚度外1/2及3/4的心肌被完全破坏后心尖旋转绝对值之和分别为4.77°±1.80°及8.39°±3.11°（P〈0.001）,心底旋转绝对值之和分别为3.62°±0.44°及2.77°±0.60°（P〈0.005）。心尖旋转绝对值之和明显增加时,心底旋转绝对值之和却显著减低。结论心尖或心底旋转绝对值之和能较好地反映心尖或心底旋转过程。

Objective To detect the relationship between apical and basal rotations of left ventricle in absolute value sums during systole.Methods To change apical rotation,14 mongrel dogs were heated at apexes,and half and three quarter of apical wall thicknesses were completely destroyed according to their corresponding heating time.Ultrasonic tissue Doppler imaging was used to detect the velocities of apical and basal rotations in the two conditions.Advanced software equipped with Philips QLAB was used to collect the values of the velocities of myocardial movement.Computer programming was used to calculate apical and basal rotations according to the formulas of velocity-time integral.Absolute value sums of apical and basal rotations during systole were the analysed parameters that were compared in the two conditions.Results When half and three quarter of apical wall thicknesses were completely destroyed,absolute value sums of apical rotations were 4.77°±1.80° and 8.39°±3.11°,respectively（P〈0.001）,and absolute value sums of basal rotations were 3.62°±0.44° and 2.77°±0.60°,respectively（P〈0.01）.As absolute value sum of apical rotation increased significantly,absolute value sum of basal rotation decreased significantly.Conclusions The fact shows that basal myocardium does not attach to fibrous skeleton totally and the structure of fibrous skeleton is not complete.Therefore,basal rotation with the potential to change to some extent which could compensate for the change of left ventricular torsion,conducing to keep left ventricular torsion constant.