超声组织追踪成像评价右心室不同位点房室顺序起搏左心室心肌力学状态差异性

摘要

[Abstrcat] Objective The difference in left ventricular myocardial mechanical patterns between right ventricular septal pacing (RVSP)and right ventricular apical pacing (RVAP) was evaluated by two-dimensional ultrasonic tissue tracking imaging (2D-TT). Methods The studied subjects were 60 patients with symptomatic bradyarrhythmia who had undergone dual-chamber atrioventricular sequential permanent pacemaker implantation.They were divided into RVSP group (n =25) and RVAP group (n =35).The 2D tis-sue Doppler images of apical four, three and two chambers were acquired.The left ventricular systolic segmental longitudinal strain ( LS) and longitudinal strain rate ( LSr) , left ventricular global longitudinal strain ( GLS) and global longitudinal strain rate ( GLSr) as well as segmental longitudinal strain peak time ( Tsl ) were measured.The interseptum-posterior wall delay ratio was calculated for the differentiation in left ventricular myocardial mechanical patterns between the two right ventricular pacing sites.Results There was no significant difference in clinical variables and echocardiographic measurements between the two groups.The LS and GLS in the RVAP group were lower than those in the RVSP group ( P<0.05) .The peak time of systolic segmental longitudinal strain in the RVAP group was significantly longer than that in the RVSP group (P<0.05).The interseptum-posterior wall delay ratio was not significantly differ -ent between the two groups (P>0.05).Conclusion RVAP induces a worse left ventricular systolic synchrony, and deteriorates the left ventricular longitudinal systolic function significantly.RVSP is prefered as a ventricular pacing site in the atrioventricular sequential cardiac pacing for better left ventricular mechanical performance.%目的：应用二维超声组织追踪成像（two－dimensional ultrasound tissue tracking imaging，2DTT）评价右心室室间隔起搏（ right ventricular septal pacing，RVSP）和右心室心尖起搏（ right ventricular apical pacing，RVAP）左心室心肌力学状态差异性。方法60例有症状缓慢性心律失常并接受永久双腔房室顺序起搏器植入术后患者，根据起搏部位不同分为RVSP组25例及RVAP组35例。均行超声心动图检查，分别获取心尖四腔、心尖三腔及心尖两腔二维图像，测量收缩期左心室节段纵向应变（longitudinal strain，LS）及节段纵向应变率（longitudinal strain rate，LSr）、左心室整体纵向应变（global longitudinal strain， GLS）、整体纵向应变率（ global longitudinal strain rate，GLSr）及节段纵向应变达峰时间（ peak time of longitudinal strain，T sl），计算间隔－后壁延迟比率，比较两种右心室起搏位点左心室心肌力学状态差异。结果两组间临床特征及常规超声心动图测量参数差异无统计学意义（ P＞0．05）。RVAP组LS值以及GLS值低于RVSP组，差异有统计学意义（ P ＜0．05）。 RVAP组节段纵向应变达峰时间较RVSP组明显延长（ P ＜0．05），间隔－后壁延迟比率差异无统计学意义（ P ＞0．05）。结论与RVSP相比， RVAP造成了明显的左心室收缩不同步和左心室纵向收缩功能减低，RVSP是房室顺序心脏起搏较好的心室位点。