右室双部位及双室起搏对心衰犬急性心功能及心室同步的影响

【目的】探讨右室5X部位及双室起搏心衰模型犬急性心功能及心室同步的影响。【方法】选取12只左束支传导阻滞的心衰模型犬，采用自身对照方法随机行右心房一右室双部位（或双室）起搏，起搏频率180次／分钟，每种方式起搏前及起搏稳定15min后行彩色多普勒超声心动图检查，测定左心室舒张末期内径（LVEDd）、左室射血分数（LVEF）、室间机械延迟（IVMD）、室间隔与左室后壁运动延迟（SPWMD）、左心室12个节段达峰时间的标准差（Ts—SD）。【结果】右室双部位起搏：与起搏前相比，LVEDd、IvMD、SPWMD、Ts—SD减小，LVEF增加，差异有显著性（P〈O．05）；与双室起搏相比，SPWMD、Ts—SD增加，差异有显著性（P〈0．05），LVEDd、IVMD、LVEF差异无显著性（P〉0．05）。【结论】在改善室间不同步及心功能方面，右室双部位与双室起搏有近似效果，但改善左室内不同步前者不及后者。

Effect of Right Ventricular Bifocal vs Biventricular Pacing on Acute Cardiac Function and Ventricular Synchronization in Dogs with Heart Failure

[Objective]To explore the efficacy of right ventricular bifocal vs hiventricular pacing for the treatment of heart failure. [Methods] Twelve dogs with heart failure and left bundle branch block were cho- sen. Right atrial-right ventricular bifocal（or biventricular） pacing was performed randomly by using own con- trol method. The pacing frequency was 180 times per minute. Color Doppler echocardiography was performed before pacing and 15 minutes after the stable pacing. Left ventricular end-diastolic diameter（LVEDd）, left ventricular ejection fraction（LVEF）, interventricular mechanical delay（IVMD）, interventricular septum and left ventricular posterior wall motion delay（SPWMD ） and left ventricular 12-segment peak time standard devi ation（Ts-SD） were measured. [Results]Compared with before pacing, LVEDd, IVMD, SPWMD and Ts-SD decreased and LVEF increased after right ventricular bifocal pacing, and there was significant difference（ P〈0.05）. Compared with biventricular pacing, SPWMD and Ts-SD increased after right ventricular bifocal pa- cing, and there was significant difference（ P 〈0.05）. There was no significant difference in LVEDd, IVMD and LVEF between two pacing modes（ P〉0.05）. [Conclusion] The efficacy of right ventricular bifocal for improving the interventricular dyssynchrony and cardiac function is similar to biventricular pacing. But the former for improving the intraventricular dyssynchrony of left ventricle is inferior to the latter.