二维斑点分层显像技术评估左束支起搏对左心室收缩功能和整体心肌做功的影响

Evaluation of left ventricular systolic function and global myocardial work in the patients with left bundle branch pacing operation by two-dimensional multi-layered speckle tracking imaging

目的:探讨二维斑点分层显像技术评估左束支起搏(left bundle branch pacing,LBBP)术后对左心室收缩功能、整体收缩同步性和整体心肌做功的影响。方法:选取2019年4-12月厦门大学附属心血管病医院42例Ⅱ度Ⅱ型或Ⅲ度房室传导阻滞(atrioventricular block,AVB)患者作为起搏组,根据起搏方式不同又分为右室间隔起搏(right ventricular septal pacing,RVSP)组(20例)和LBBP组(22例);同期选择20例年龄、性别相匹配的心电图及心内结构正常并符合排除标准者作为对照组。采集起搏组术后1周及对照组的二维动态声图像,脱机分析左室18节段心内膜下心肌纵向应变峰值(subendocardial myocardial longitudinal strain peak,LSendo)、中层心肌纵向应变峰值(the middle layer myocardial longitudinal strain peak,LSmid)、心外膜下心肌纵向应变峰值(subepicardium myocardial longitudinal strain peak,LSepi)、整体心肌纵向应变峰值(global myocardial longitudinal strain peak,GLS)、应变达峰时间弥散度(peak strain dispersion,PSD)以及心肌做功指数(global work index,GWI)、心肌有效做功(global constructive work,GCW)、心肌无效做功(global wasted work,GWW)和心肌做功效率(global work efficiency,GWE)等参数。统计分析三组间差异并建模筛选高差异指标。结果:对照组、LBBP组及RVSP组组间LSendo差异无统计学意义(P>0.05),LSmid、LSepi及GLS逐渐减低(P<0.05);与RVSP组比较,LBBP组GLS增大(P<0.05)。LBBP组QRS波宽度及PSD相较对照组差异无统计学意义(P>0.05),而较RVSP组明显降低(P<0.05)。三组间GCW差异无统计学意义(P>0.05);与对照组相比,LBBP组GWI差异无统计学意义(P>0.05),GWW增加,GWE降低(P<0.05);与RVSP组相比,LBBP组GWI、GWE增加,GWW降低(P<0.05)。模型筛选出QRS波、LSendo、GLS、LSmid及左室心尖部和基底段旋转达峰时间间期为起搏组间显著差异指标;通过部分依赖分析显著差异指标特征显示LBBP组均优于RVSP组。结论:二维斑点分层显像技术可以用于评估LBBP对左心室收缩功能、整体收缩同步性及心肌做功的影响;LBBP纵向机械同步性优于RVSP,可明显改善左室纵向收缩功能及心肌做功。

Objective To assess the changes of left ventricular systolic function and global synchronization and myocardial work in patients with left bundle branch pacing(LBBP)by two-dimensional multi-layered speckle tracking imaging.Methods Forty-two patients withⅡdegreeⅡtype orⅢdegree atrioventricular block(AVB)in the Cardiovascular Hospital of Xiamen University from April to December 2019 were selected as pacing group,which were further divided into two groups according to different pacemaker modes:twenty patients with right ventricular septal pacing(RVSP),twenty-two patients with LBBP,and twenty patients with normal ECG and cardiac structure were enrolled as control group.Echocardiography of pacing group and control group was performed and analyzed.The left ventricular subendocardial longitudinal strain peak(LSendo),the middle layer myocardial longitudinal strain peak(LSmid),subepicardial longitudinal strain peak(LSepi),global myocardial longitudinal strain peak(GLS),peak strain dispersion(PSD),global work index(GWI),global constructive work(GCW),global wasted work(GWW)and global work efficiency(GWE)were acquired.The differences among the three groups were analyzed and the high difference indexes were screened by statistical modeling.Results LSendo in three groups had no difference(P>0.05).LSmid,LSepi,GLS in the control group,LBBP group and RVSP groups were decreased gradually(P<0.05).GLS in LBBP group was higher than in RVSP group(P<0.05).Compared with the control group,the increases of QRS and PSD in LBBP group were not statistically significant(P>0.05),while the decreases of QRS and PSD in LBBP group were statistically significant compared with the RVSP group(P<0.05).The values of GCW among three groups had no statistical significance(P>0.05).Compared with the control group,the decrease of GWI in LBBP group was not statistically significant(P>0.05),while the increase of GWW and the decrease of GWE were statistically significant(P<0.05).Compared with the RVSP group,the increases of GWI and GWE and the decrease of GWW in LBBP group were statistically significant(P<0.05).QRS,LSendo,GLS,LSmid,left ventricular apex rotation to basal rotation peak time(ApexBase period)were the indexes with significant difference among LBBP and RVSP groups and all index characteristics showed better in LBBP than RVSP group.Conclusions Two-dimensional multi-layered speckle tracking imaging can be used to evaluate the effect of LBBP on left ventricular systolic function and global synchronization and myocardial work.LBBP longitudinal mechanical synchronization is better than right ventricular septal pacing by improving the peak global myocardial longitudinal strain and myocardial work after pacemaker.