速度向量成像技术评价冠状动脉搭桥术患者的左心室扭转

Assessment of left ventricular torsion in patients after coronary artery bypass graft by velocity vector imaging

目的应用速度向量成像（VVI）技术研究冠状动脉搭桥术（CABG）患者术前、术后左室心肌扭转角度及速度的变化规律，探讨其临床应用价值。方法采用Siemens Sequoia C512超声诊断仪及VVI技术对12例CABG患者术前及术后3个月左室心尖部和心底部各节段心肌旋转角度和速度进行定量分析。结果①术前患者心尖部心肌旋转为逆时针方向，心底部心肌旋转为顺时针方向，心尖部旋转角度绝对值明显高于心底部，差异有统计学意义（P〈0．001）；②术后3个月心底部心肌旋转角度明显高于术前水平（-6．20°±4．18°对-3．13°±2．64°，P〈0．001），其中心底部前间隔、前壁及后间隔的心肌旋转角度高于术前相应水平，差异有统计学意义（P〈0．05）；③左心室扭转角度显著高于术前水平（12．74°±5．94°对9．58°±4．69°，P〈0．001）；④术前患者心尖部收缩末期正向峰值旋转速度和舒张早期负向峰值旋转速度均明显高于心底部水平[（49．70±29．89）°／s对（26．41±11．53）°／s，（-47．40±28．93）°／s对（-28．59±14．26）°／s]，差异有统计学意义（P〈0．001）；⑤术后3个月心底部收缩末期平均正向峰值旋转速度和舒张早期平均负向峰值旋转速度均显著高于术前水平，差异有统计学意义（P〈0．001），其中心底部前间隔、前壁、侧壁及后间隔的收缩末期正向峰值旋转速度、前间隔及后间隔的舒张早期负向峰值旋转速度高于术前相应水平，差异有统计学意义（P〈0．01或P〈0．05）。结论VVI技术能定量评价CABG患者左室心尖部和心底部各节段心肌旋转角度和速度，为临床评价CABG患者左心室扭转的变化提供了有效方法。

Objective To evaluate left ventricular torsion in patients after coronary artery bypass graft（CABG） surgery by velocity vector imaging（VVI）. Methods Twelve patients who were scheduled to have CABG surgery were enrolled. VVI offline software was used to evaluate myocardial rotation in both basal and apical segment before and three months after CABG. The rotation and rotation rate of each segment were measured. Results （1）Before the surgery,the left ventricle performed a wringing motion with a counterclockwise rotation at the apex and a clockwise rotation at the base, and the absolute value of rotation at the apex was significantly higher than that at the base （ P 〈0. 001 ）. （2） Three months after CABG the rotation at the base was significantly improved than that before CABG （ P 〈0. 001）, and the rotation in the segment of anterior septum,anterior wall and inferior septum at the base was higher than that before CABG （ P〈0.05）. （3）The left ventrieular twist, which was acquired by the difference between the rotation in the apical and basal segment three months after CABG was also significantly higher than that before it （P 〈0. 001 ）.（4）Before CABG the positive peak rotation rate in the late systolic period and the negative peak rotation rate in the early diastolic period at the apex were significantly higher than those at the base （ P 〈 0.001）. （5） Three months after CABG the peak rotation rate at the base was significantly improved than that before CABG （ P 〈0. 001 ）. And the positive peak rotation of the systolic period in the segment of anterior septum,anterior wall,lateral wall and inferior septum and the negative peak rotation of the diastolic period in the segment of anterior and inferior septum at the base were also higher than those before CABG （ P 〈 0. 001）. Conclusions VVI is a useful method which can quantitatively assess left ventricular torsion in patients before and after CABG surgery.