一种反映左室射血特性的校正方法

利用脉冲多普勒超声心动图测定主动脉瓣前向血流加速度是一项反映左室收缩力的指标，但其受腔室大小的影响，为了克服该影响，我们采用ＩｓａａｚＫ等校正主动脉血流速度的方法校正加速度，校正的方法为Ａｃ＿１（校正后的加速度）＝ＣＳＡ／Ａ＿１×Ａｃ，Ａｃ＿２（校正后的加速度）＝ＣＳＡ／Ａ＿２×Ａｃ，ＣＳＡ为主动脉瓣环截面积，Ａ＿１为左室舒张末期横截面积，Ａ＿２为主动脉瓣峰值血流时的左室横截面积，Ａｃ为未校正的主动脉瓣加速度。结果示组二（左室射血分数＜６０％）的Ａｃ与组一和组三（左室射血分数＞６０％）有较大的重叠，但校正后的Ａｃ＿１和Ａｃ＿２无重叠，表明Ａｃ＿１和Ａｃ＿２不受腔室大小的影响，可以更好地反映左室射血特性，由于Ａｃ＿１测定简便，效果与Ａｃ＿２相似，是一项更为可行的方法。

A Normalized Left Ventricular Ejection Performance Estimated by M-mode and Doppler Echocardiography

In order to overcome the influence of left ventricular(LV) size on aortic blood acceleration(Ac),16 patients with LV ejection fraction<60%,15 patients with IV ejection fractio<60% and 20 normal people were studied by M-mode 2-dimensional and Doppler echocardiography.Ac was normalized by the ratio ofleft ventricle to aortic cross-sectional area. The results showed:Ac had a significant overlap between patients with normal and abnormal LV function,whereas normalized Ac was a better discriminator. The simplified nor- malized index derived by substituting the square of the ratio of LV end-diastolic to aortic area for the ratio of LV cross sectional area during peak aortic blood velocity to aortic area was also reliable ejection index.