左心室局部射血分数计算方法的理论缺陷:(Ⅰ)基于正常室壁运动模型对面积参数的数学证明

INHERENT DEFECT IN ALGORITHM OF LEFT VENTRICULAR REGIONAL EJECTION FRACTION(1):MATHEMATIC ANALYSIS OF AREAPARAMETER ON NORMAL LV WALL MOTION MODEL

在正常收缩心脏的左心室长轴切面模型的基础上，应用数学方法证明，极坐标定量分析方法导致局部射血分数低估心尖部及心底部功能，靠近中心点的室壁功能被高估，远离中心点的节段功能被低估，长轴及中心点的偏移越大则误差越大，导致节段功能测量误差的原因是由于左心室的二维图像是非全对称几何体，舒张末中心点与周边心内膜不等距。

In this study,we proved mathematically that polar coordinated system(PCS) used commonly in analyzing LV regional wall motion(RWM) had its inherent defect.RWM analyzed quantitatively by method of PCS will lead to underestimate the function of apex and base part in image of LV long axis sections.The reason is that the different distance exists between the centroid of LV enddiastole image and the endocardium of each segment.Shifting of centroid and long axis results in underestimating the function of the segment far from the centroid and overestimating the function of the segment close to the centroid.So REF cannot reflect true changes of different segments in contraction.