左心室心外膜不同部位起搏对心室不应期离散度的影响  

Influence of left ventricular epicardial pacing site on dispersion of refractoriness

作　　者：林长坚[1] 金奇[1] 张凝[1] 周建[1] 庞旸[1] 任淑静[1] 顾刚[1] 陈颖[1] 吴立群[1] 

机构地区：[1]上海交通大学医学院附属瑞金医院心脏科,上海200025

出　　处：《内科理论与实践》2011年第4期298-301,共4页Journal of Internal Medicine Concepts & Practice

基　　金：国家自然科学基金(项目编号:81070266;81000081);上海市科委课题(项目编号:10140903100);上海高校创新团队发展计划

摘　　要：目的:通过模拟心脏再同步治疗中左室电极在左心室心外膜不同部位起搏情况,观察不同部位起搏对心室不应期离散度的影响。方法:采用6只犬开胸,在其左心室前侧壁心外膜缝上1块含有144(12×12)个单极电极(电极间距2 mm)的电极板。选取位于电极板对角处的2个起搏部位(左上角靠近心底部,右下角靠近心尖部),采用连续起搏方法,记录起搏周期为300 ms时整个电极板上每个单极电极上的激动恢复间期,通过其标准差及变异系数评估不应期离散度。结果:近心底部与近心尖部起搏时起搏阈值及心室激动恢复间期无显著差异[起搏阈值(0.34±0.22)mA比(0.26±0.05)mA;激动恢复间期(144.3±12.4)ms比(147.7±14.8)ms,均P>0.05]。但是,近心底部位起博的不应期离散度较近心尖部起搏的不应期离散度显著减小[标准差(4.3±0.8)ms比(5.8±0.7)ms,P<0.01;变异系数(0.030±0.006)比(0.039±0.005),P<0.01]。结论:在心脏再同步治疗左室电极植入过程中,选择恰当的左室电极植入部位有利于降低不应期离散度。Objective Dispersion of refractoriness is closely related to the induction of ventricular arrhythmia. The goal of this study was to evaluate the influence of left ventricular （LV） epicardial pacing site on the dispersion of refractoriness by mimicking LV electrode implantation during cardiac resynchronization therapy （CRT）. Methods A plaque containing 144 （12×12） unipolar electrodes （2 mm spacing） was sutured on the anterolateral epicardium of LV in six open-chest beagles. Two sites on diagonal of the plaque were selected for pacing. The upper left site was close to the base of LV, while the lower right one was near the apex of LV. The S1S1 restitution pacing protocol was used to evaluate the activation recovery interval （ARI） at the pacing cycle length of 300 ms. The dispersion of refractoriness was evaluated by standard deviation （SD） and coefficient of variation （CV） of ARI. Results The ARIs and pacing threshold measured were not significantly different between these two pacing sites [pacing threshold（0.34±0.22）mA vs （0.26±0.05）mA;ARI（144.3±12.4）ms vs （147.7±14.8）ms, P〉0.05）]. However, dispersion of refractoriness was significantly decreased when pacing at the site close to the base of LV compared to pacing at the site near the apex [SD （4.3±0.8）ms vs （5.8±0.7）ms,P〈0.01 ;CV （0.030± 0.006） vs （0.039±0.005）, P〈0.01]. Conclusions The results of this study indicated that optimized selection of LV epicardial pacing site would have beneficial effects on dispersion of refractoriness during LV electrode implantation of CRT.

关 键 词：心脏再同步治疗 激动恢复间期 不应期 电生理 

分 类 号：R541.7[医药卫生—心血管疾病]