犬心房-希氏束顺序起搏的心电生理学和血液动力学研究

STUDY OF ATRIA-HIS BUNDLE SEQUENTIAL PACING ON CARDIAC ELECTROPHYSIOLOGY AND HEAMODYNAMICS IN DOGS

目的 :探讨心房希氏束顺序起搏时心脏电生理和血液动力学效应 ,为临床开展生理性心脏起搏提供理论依据。方法 :健康犬 2 0只 ,全麻机械通气下 ,开胸暴露心脏 ,将特制希氏束 (HisBundle ,HisB)标测 起搏电极进行His束电图标测 ,选择最佳His束起搏位点 ,并与右心房 (rightatria,RA)、右室尖部 (rightventricularapex ,RVA)心外膜起搏位点组合成不同的心脏起搏模式 ,比较RA AAI、HisB VVI、RVA VVI单腔按需型心脏起搏和RA HisBDDI、RA RVADDI双腔按需型心脏起搏时的心脏电生理学和血液动力学参数变化特点。结果 :HisB起搏阈值接近于RVA起搏 ;RAAAI、HisB VVI和RA HisBDDI起搏时心输出量 (CO)较起搏前均有不同程度提高 ,RA HisBDDI起搏CO提高最显著约 2 9.6 4%(P <0 .0 1) ,RA RVADDI起搏提高约 0 .2 5 % (P >0 .0 5 )、单RVA VVI起搏则降低约 5 .41% (P >0 .0 5 ) ,每搏量 (SV)、左室每搏功 (LVSW)和右室每搏功 (RVSW)等参数明显优于RVAVVI和RA RVADDI起搏。结论 :HisB VVI和RA HisBDDI起搏由于将起搏位点从传统的右室尖改为His束 ,从而保持了近于正常生理性房室激动顺序和心室收缩同步性 ,故可维持整个心脏协调有序的收缩和舒张 ,产生优于RVA VVI、RA RVADDI起搏的血液动力学效果 。

Aim:To evaluate the effects of atria-His bundle sequential pacing on cardiac electrophysiology and heamodynamics in dogs. Methods:In 20 opening chest anesthetized dogs, platinum electrodes were fixed at the epicardium of right atria (RA) and the right ventricular apex (RVA) respectively,pacing right atria and the right ventricle. A special lead was located at His bundle (based on a optical 'H' wave and narrow duration of the QRS complexes recorded in ECG),pacing His bundle. Cardiac electrophysiology and hemodynamics parameters were compared in the different pacing models RA AAI,RVA- VVI,HisB- VVI single chamber pacing and RA-RVA DDI,RA-HisB DDI dual chamber pacing. Results:The threshold of His B pacing is similar to that of RVA pacing. Cardiac output(CO)is increased in pacing of RA AAI,His B- VVI and RA-His B DDI. It is increased by 29.64% in pacing of RA-His B DDI (P<0.01) and by 0.25%(P>0.05) in pacing of RA-RVA DDI . While CO is decreased by 5.41% in RVA- VVI pacing(P>0.05). SV,LVSW and RVSW of RA-HisB DDI pacing are superior to those in RVA- VVI and RA-RVA DDI pacing. Conclusion:Right atria-His bundle sequence pacing significantly improves cardiac function compared with the other model pacing because it maintains normal physiological electronic activity sequence and systolic synchrony. It will be adapted to clinical application.