犬左心室不同激动顺序收缩期容量与压力的超声研究

目的 应用三维全容积成像技术评价正常犬收缩期左事整体和节段容量及压力变化,评价不同电机械兴奋顺序时左室整体及节段收缩功能与同步化程度.方法 19只开胸比格犬模型,分别在基础状态(BASE)和右心耳(RAA)、右室心尖(RVA)、左室侧壁(LVL)、左室心尖(LVA)起搏状态采集左室全容积图像;同步记录左室流出道收缩末压力(ESP);脱机分析左室收缩末容积(ESV)、左室舒张末容积(EDV),计算整体及17节段射血分数(EF)、节段容积同步化指数(SDI)、左室收缩期压力平均上升速率(+dp/dt)和舒张期压力平均下降速率(-dp/dt).对各参数行配对t检验、方差分析和线性相关分析.结果 ①RVA组左室整体EF、ESP、+dp/dt、-dp/dt较RAA组减低,SDI较RAA组增大(P<0.05);LVL组及LVA组整体EF与RAA组问差异均无统计学意义(P>0.05),ESP,+dp/dt、-dp/dt均较RAA组减低,SDI均较RAA组增大(P<0.05).②LVL组及LVA组EF均较RVA组增高,LVL组SDI较RVA组减低(P<0.05),LVA组SDI与RVA组间差异无统计学意义.③LVL组整体EF、SDI、ESP、+dp/dt及-dp/dt与LVA组间差异无统计学意义;LVA组间隔、心尖节段EF较LVL组减低(P<0.05).④RVA组前、后间隔、心尖(除侧壁外)节段EF较RAA组减低(P<0.05);LVL组侧壁、前壁节段EF较RAA组减低;LVA起搏组前壁、前间隔、心尖节段EF较RAA组减低(P<0.05).⑤左室容积与压力参数间未能建立线性相关关系.结论 RAA起搏左室整体及少数节段收缩功能低于窦性心律;RAA起搏左室收缩与舒张功能均优于心室起博;LVL起搏左室收缩功能明显优于RVA起搏;心室起搏后,起搏位点周围左室节段收缩功能下降.

The ultrasonic research of left ventricular systolic volume and pressure in different electro-mechanical patterns:a canine model

Objeetive To evaluate the changes of left ventricular(LV) global and segmental volume, LV outlet pressure and their co-relationship, and to access LV global and segmental systolic function and mechanical asynchrony in different LV electro-mechanical patterns using full volume three-dimensional echocardiography(3DE). Methods Nineteen open-chest canine models were employed for the acquirement of LV full volume dynamic 3DE imaging during right atrial appendage (RAA), right ventricular apical (RVA), LV lateral wall(LVL) and LV apical(LVA). LV outlet end-systolic pressure(ESP) was recorded simultaneously. End-systolic volume (ESV), end-diastolic volume (EDV), global and segmental ejection fraction(EF) and systolic dyssynchrony index(SDI) of LV were measured and calculated using a dedicated workstation. The average ascending rate of LV pressure during systole(+ dp/dt) and the average descending systolic pressure(ESP), + dp/dt and - dp/dt during RVA pacing were lower than those during RAA pacing (P <0.05). SDI during RVA pacing was higher than that during RAA pacing(P<0.05). ESP, + dp/dtand - dp/dt during LVL and LVA pacing were lower than those during RAA pacing (P <0.05). There and LVA pacing was higher than that during RVA pacing (P <0.05),SD1 during LVL pacing was lower than that during RVA pacing (P <0.05), there was no significant difference of SDI between RVA and LVA and LVL pacing. Segmental EF of septum and apex during LVI. pacing were higher than those during LVA pacing (P <0.05). @Segmental EF of anterior and post septum and all apical segments (except lateral wall) during RVA pacing were lower than those during RAA pacing (P <0.05). Segmental EF of lateral and anterior wall during I.VI. pacing were lower than those during RAA pacing (P <0.05). Segmental EF of anterior wall and anterior septum during LVA pacing were lower than those during RAA parameters. Conclusions The global and minority segmental systolic function of LV during RAA pacing could be reduced compared with normal sinus rhythm. All the ventricular pacing worsen LV systolic and diastolic function compared with RAA pacing. LV systolic function during LVL pacing was superior to RVA pacing. During ventricular pacing,the systolic function at nearby segments of the pacing site was depressed.