斑点追踪成像在肥厚型梗阻性心肌病患者室间隔酒精消融术后随访中的应用价值

Value of speckle tracking imaging in postoperative follow-up of alcohol septal ablation for hypertrophic obstructive cardiomyopathy: report of 19 cases

目的探讨斑点追踪成像（speckle tracking imaging,STI）在肥厚型梗阻性心肌病（hypertrophic obstructive cardiomyopathy,HOCM）患者行室间隔酒精消融术（alcohol septal ablation,ASA）术后随访中的应用价值。方法对照组为30例健康志愿者,其中男性16例,女性14例,年龄28~40（34.30±6.10）岁;病例组为2012年4月至2014年7月西南医院心内科住院部HOCM患者19例,其中男性8例,女性11例,年龄32~67（46.53±11.66）岁;对照组和病例组均行超声检查（病例组为ASA术前和术后3 d,1、3、6个月共5次）,获得左心室射血分数（left ventricular ejection fraction,LVEF）、左心室流出道压力阶差（left ventricular outflow tract pressure gradient,LVOTG）、室间隔（interventricular septum,IVS）厚度等指标;同时应用STI技术、QLAB软件获得左室各节段纵向、径向、周向收缩期峰值应变及应变率,将左室心肌分为肥厚节段和非肥厚节段,分别比较以上各指标在不同时期的差异。结果HOCM患者术前和术后3 d,1、3、6个月LVOTG较对照组增高（P〈0.05）,术后LVOTG较术前明显下降（P〈0.05）。术后3 d IVS厚度较术前稍有下降,术后1、3、6个月IVS厚度明显低于术前（P〈0.05）。术前及术后各随访时间点所测LVEF均无统计学差异（P〉0.05）。肥厚节段术前、术后各方向收缩期峰值应变（率）均低于对照组（P〈0.05）。与术前比较,肥厚节段术后3 d各方向应变（率）差异无统计学意义（P〉0.05）;术后1、3、6个月各方向收缩期峰值应变（率）均增高（P〈0.05）。术前及术后肥厚节段应变（率）均低于非肥厚节段（P〈0.05）。非肥厚节段、术前纵向应变（率）低于对照组（P〈0.05）,而术后各随访时间点纵向应变（率）高于术前（P〈0.05）,并且与对照组无明显差异（P〉0.05）。结论应用STI技术评价HOCM患者应变及应变率的变化,反映出HOCM患者行ASA能够提高肥厚心肌节段的局部心功能,并且能帮助非肥厚心肌节段恢复心功能;STI技术能够成为HOCM患者ASA术后长期随访的一种准确、无创、可重复性强的影像学手段。

Objective To determine the value of speckle tracking imaging（ STI） in the evaluation of postoperative follow-up of the patients with hypertrophic obstructive cardiomyopathy（ HOCM） after（ alcohol septal ablation,ASA）. Methods The enrolled subjects included healthy volunteers（ control group,n = 30）and case group（ n = 19） in this study. There were 16 males and 14 females aged from 28 to 40 years old（ average age 34. 30 ± 6. 10） in the control group,and 8 male and 11 female HOCM patients at an age of 32 to67 years old（ average age 46. 53 ± 11. 66） who hospitalized in the cardiology department from April 2012 to July 2014. The former group underwent echocardiography and STI,while the latter underwent the same ultrasonographic examination at 5 time points,including the pre-operation and in 3 d,and 1,3 and 6 months after operation. Left ventricular ejection fraction（ LVEF）,left ventricular outflow tract pressure gradient（ LVOTG） and interventricular septum（ IVS） were measured by echocardiography. And peak systolic longitudinal strain（ LS）, longitudinal strain（ LSr）, radial strain（ RS）, radial strain rate（ RSr）,circumferential strain（ CS） and circumferential strain rate（ CSr） of hypertrophy and non-hypertrophy segments of left ventricle were measured by STI and Qlab Software. And then these parameters were statistically analyzed. Results LVOTG of HOCM at the 5 time points from the case group were significantly higher than those of control group（ P 〈 0. 05）,and were obviously declined after ASA（ P 〈 0. 05）.Compared with the pre-operative value,the thickness of IVS was slightly declined in 3 d post-operatively,and remarkably decreased in 1,3 and 6 months after operation（ P 〈 0. 05）. There was no significant difference in the LVEF at the 5 time points（ P 〉 0. 05）. For the hypertrophic segments,all of the peak systolic strains and strain rates were obviously lower in the case group than control group（ P 〈 0. 05）. Though no marked difference were seen in all strains and strain rates of hypertrophic segments between pre-operation and 3 d after operation（ P 〉 0. 05）,the parameters were significantly increased in 1,3 and 6 months post-operatively when compared with those before operation（ P 〈 0. 05）. The strains and strain rates of hypertrophic segments were obviously lower in our whole observation period than those of non-hypertrophic segments（ P 〈 0. 05）. Before ASA,the LS and LSr of non-hypertrophy segments were obviously lower than those of control group（ P 〈0. 05）,but they were notably higher than before ASA（ P 〈 0. 05） and had no significant difference with normal group（ P 〉 0. 05）. Conclusion STI,as a new technique,can evaluate the dynamic changes of local strain and strain rates of left ventricle,and reflect the restoration of non-hypertrophy segments’ function in the patients with HOCM after ASA. So, it might be an accurate, noninvasive and repeatable method for postoperative evaluation of ASA for HOCM.