右室不同部位起搏对左室收缩同步性及心功能影响的超声研究

目的:应用实时三维超声心动图及其定量技术,分析右室不同部位起搏即刻左室收缩同步性和收缩功能的变化。方法:建立犬右室心尖部(RVA)(n=6)和右室流出道(RVOT)(n=6)起搏模型,分别采集窦性心律(SR)、RVA及RVOT起搏3种状态下经胸超声心动图实时三维全容积图(RT-3DE)。应用左室定量容积分析软件,获取左室整体及16节段容积时间曲线,分别计算16节段、12节段(中间段和基底段)、6节段(基底段)最小收缩容积到QRS波起始点时间(Tmsv)的标准差(Tmsv-SD)和最大差值的绝对值(Tmsv-Dif)及其占心动周期的百分比(Tmsv-SD%,Tmsv-Dif%)、左室舒张末容积(EDV)、左室收缩末容积(ESV)、左室每搏输出量(SV),左室射血分数(LVEF)。结果:与SR组比较,RVOT起搏组各参数均无统计学差异(P>0.05),RVA起搏组Tmsv-16SD%、Tmsv-12SD%、Tmsv-6SD%、Tmsv-16Dif%、Tmsv-12Dif%、Tmsv-6Dif%均有统计学差异(P<0.01),LVEF明显降低(P<0.05),EDV及SV减小、ESV增大,但差异无统计学意义(P>0...

Echocardiographic assessment of left ventricular systolic synchronicity and function during pacing at variant right ventricular sites

Objective:To assess left ventricular systolic synchronicity and function with right ventricular out tract(RVOT) pacing or right ventricular apex(RVA) pacing by real-time three-dimensional echocardiography(RT-3DE).Methods:In the acute tests of anesthetized closed-chest beagle canines,acustom designed bipolar screw-in lead was implanted using a steerable delivery catheter guided with X-ray.The bipolar leads were implanted in the right ventricular apex or the right ventricular out tract.The dogs received right...