二维斑点追踪技术评价肥厚型心肌病左房功能的研究

Evaluation of Left Atrial Function in Patients with Hypertrophic Cardiomyopathy by Two-dimensional Speckle Tracking

目的探讨应用二维斑点追踪技术(2DT)评价肥厚型心肌病(HCM)患者左房功能的价值。方法 HCM组患者28例,健康对照组30例,测量其左房内径,室间隔及左室后壁厚度,左室流出道压差,二尖瓣口E、A峰值,计算E/A值,计算左房主动排空分数(LAAEF)及左房被动排空分数(LAPEF)。应用2DT技术,获取房间隔、左房侧壁、下壁及前壁的基底段、中间段及房顶段的长轴方向的应变及应变率曲线,记录各房壁各节段左室收缩期峰值应变及应变率(Ss、SRs)、舒张早期峰值应变率(SRe)、舒张晚期峰值应变率(SRa),计算其平均值(mSs、mSRs、mSRe、mSRa)。结果 HCM组左房内径、室间隔及左室后壁厚度、左室流出道压差、A峰及LAAEF显著大于对照组(P<0.05),E峰、E/A及LAPEF则显著低于对照组(P<0.01);HCM组与对照组比较,HCM组左房mSs、mSRs、mSRe均明显减低,mSRa则明显增高,差异均有统计学意义(P<0.01);HCM患者左房mSRa与LAAEF呈显著正相关(r=0.780,P<0.01)。结论 HCM患者左房的储备功能及管道功能下降,辅泵功能增加,2DT可以准确评价左心房功能的变化。

Objective To explore the value of two-dimensional speckle tracking in detecting left atrial function in patients with hypertrophic eardiomyopathy（HCM）.Methods There were 28 patients with HCM and 30 healthy control subjects enrolled in our study.Left atrial diameter,interventricular septal thickness,left ventricular posterior wall thickness,pressure gradients of left ventricular outflow tract,peak E and A of mitralis（E,A） and E/A were measured by conventional echocardiography.Left atrial active ejection fraction（LAAEF） and left atrial passive ejection fraction（LAPEF） were calculated with Simpson＇s method.The longitudinal strain and strain rate curves were acquired in the basal、middle and apical segments of each LA segment（septal,lateral,inferior,and anterior） by two-dimensional speckle tracking.The peak systolic stain,peak systolic stain rate（SRs）,peak early diastolic stain rate（SRe） and peak late diastolic strain rate（SRa） were measured in patients and control subjects,while the mean peak strain and mean peak strain rates（mSs,mSRs,mSRe,and mSRa） were also calculated by averaging data in all segments.Results ① Compared with controls group,left atrial diameter,interventricular septal thickness,left ventricular posterior wall thickness,pressure gradients of left ventricular outflow tract,peak A and LAAEF in HCM group were significantly higher（P0.05） while peak E,E/A and LAPEF significantly decreased（P0.01）.② mSs,mSRs,and mSRe in HCM group were significantly lower than those in controls group,while mSRa in HCM group was significantly higher than that in controls group.③ mSRa correlated positively with LAAEF in HCM group（r=0.780,P0.01）.Conclusion The change of left atrial function of HCM presented as reservoir and conduit functions decreased and pump function increased.Two-dimensional speckle tracking could accurately evaluate the left atrial function and provide important clinical information.