STI评价主动脉瓣狭窄患者瓣膜置换术前后左室收缩功能

STI Study of the Changes in Left Ventricular Systolic Function after Valve Replacement for Aortic Stenosis

目的应用二维斑点追踪显像(STI)检测射血分数正常的主动脉瓣狭窄(AS)患者瓣膜置换术(AVR)前后左心室心肌整体应变、应变率的变化,并探讨其临床应用价值。方法 35例主动脉瓣狭窄且左室射血分数正常并拟行AVR的患者,年龄35~55岁,平均(43.5±4.2)岁,分别于术前、术后1个月及术后6个月通过超声心动图斑点追踪显像技术对左室整体(纵向,径向和圆周)应变及应变率进行测量分析,结果与30例正常人进行对照比较。结果患者术前、术后与正常对照组及术前与术后比较左室短轴径向、圆周向应变及应变率均未见明显差异。左室心肌长轴纵向应变及应变率结果显示,术前、术后1个月及术后6个月左室纵向应变及应变率均低于正常对照组,术后1个月低于术前及术后6个月,术后6个月左室心肌纵向应变及应变率有所恢复并高于术前,差别均具有统计学意义(P<0.05),即正常对照组>术后6个月>术前>术后1个月。结论 STI可以较常规超声更精确地检测到LVEF尚在正常范围内的AS患者左室心肌应变及应变率的改变,于AVR术后对其早期恢复的检测亦有重要的临床价值。

Objective To investigate the effects of aortic valve replacement （AVR） on left ventricular sunin and strain rate in patients with aortic stenosis （AS） by using two- dimensional speckle tracking imaging （STI）. Methods Thirty -five AS patients underwent AVR were enrolled for the study. Left ventricular short axis and apex aspect images were acquired at basehne before AVR, one month and six months after AVR. STI was em- ployed to detect the systohc strain parameters of these AS patients ： peak longitudinal, radial, circumferential strain and strain rate. Thirty healthy in- dividuals were also recruited as control, and a comparative analysis was done. Results There was no significant di^rece in the circumferential and radial strain and strain rate comparing AS patients with healthy controls （P 〉 0.05 ） . The longitudinal strain and strain rate are reduced in AS pa- tients. One month after AVR, two-dimensional longitudinal strain and strain rate are lower than before AVR and postoperative six months. Six months after AVR, the longitudinal strain and strain rate are improved compared with before operation, but still lower than normal controls （P 〈 0.05 ） . In other words, normal controls〉 six months after AVR 〉before AVR 〉one month after AVR. Conclusion AVR can improve the longitudinal strain and strain rate in AS patients who maintained LV ejection fraction. STI can evaluate this changing process more accurate than conventional ultra- sound. STI also has important clinical value for detecting the recovery of left ventricular myocardium after operation.