斑点追踪显像对房间隔缺损患者左心旋转和扭转运动的初步研究

目的 探讨房间隔缺损(ASD)患者右心容量负荷和压力负荷过重对左心旋转和扭转运动的影响.方法 应用斑点追踪显像技术分别测量35例单纯ASD患者(其中18例伴肺动脉高压)左室基底部短轴和心尖部短轴6个节段的旋转峰值及其收缩早期反方向旋转的平均峰值和平均持续时间;绘制左室扭转-时间曲线,计算扭转峰值及达峰时间;双平面Simpson法测量左室射血分数(EF).21例正常人作为对照组.结果 与ASD肺动脉高压阴性组及正常组相比,ASD肺动脉高压阳性组基底部后壁、下壁、后室间隔的顺时针旋转角度峰值降低(P＜0.05),6个节段早期逆时针旋转的平均峰值增加(P＜0.05),平均持续时间延长(P＜0.05),左室整体扭转角度峰值亦降低(P＜0.05).ASD肺动脉高压阴性组各指标与正常组的差异无统计学意义.左室扭转角度峰值与肺动脉收缩压呈明显负相关(r=-0.57,P=0.001).三组间射血分数无明显差异.结论 单纯ASD引起的右心容量负荷增加并不明显改变左室旋转和扭转运动,而肺动脉压增高时左室扭转峰值降低,且与肺动脉收缩压呈明显负相关.

Evaluation of left ventricular rotation and twist using speckle tracking imaging in patients with atrial septal defect

Objective To investigate the effect of right ventricular(RV)volume and RV pressure overload on left ventricular(LV)rotation and twist in patients with atrial septal defecl(ASD).Methods Using speckle tracking imaging(STI),the peak rotation of 6 segments in basal and apical short-axises was measured respectively in 35 patients with ASD(18 of which with pulmonary hypertension)and 21 healthy subjects as controls.The average peak rotation and duration time of the 6 segments in basal and apical short-axises in negative direction during early systolic phase were also measured respectively.LV twist versus time profile was drawn and the peak twist and time to peak twist were calculated.LV ejection fraction(EF)was measured by biplane Simpson method.Results Compared to ASD patients without pulmonary hypertension and healthy subjects,the peak rotation of posterior wall,inferior wall and postsept wall in basal was lower(P＜0.05).And at the basal level,the averagepeak rotation of 6 segments in negative direction during early systolic phase was higher(P＜0.05),and the average duration time was delayed(P＜0.05).LV peak twist was also lower(P＜0.05),and had a significant negative correlation with pulmonary arterial systolic pressure(r=-0.57,P=0.001).There were no significant differences in LVEF among 3 groups.Conclusions Although RV volume overload due to ASD has no significant effects on LV rotation and twist,LV peak twist is lower in ASD patients with pulmonary hypertension.Thus LV twist may be a new index which predicting whether ASD patients also has pulmonary hypertension or not.