绝对不应期电刺激对心室肌收缩功能的影响  

作　　者：张海柱[1] 崔长琮[2] 

机构地区：[1]安阳市人民医院心内科,455000 [2]西安交通大学第一医院心内科,710061

出　　处：《求医问药（下半月刊）》2011年第12期424-425,共2页Seek Medical and Ask The Medicine

摘　　要：目的:观察绝对不应期电刺激对兔离体乳头肌收缩功能的影响。方法:分离兔右心室乳头肌、灌流并给予1HZ刺激使其等长收缩,于该基础刺激的绝对不应期给予双相方波电流刺激(称之CCM)。观察乳头肌的最大张力(PT)及其微分(+dT/dt)的变化。结果:和CCM刺激前相比,CCM刺激时PT及其+dT/dt比刺激前分别增加18.2%和21.4%(P<0.05),且PT随着第一次CCM刺激就开始增加,在几次CCM刺激后达到稳定的水平,CCM刺激一旦停止,张力就恢复到刺激前的水平。实验还发现,CCM对乳头肌张力的作用大小存在着电压量效反应,刺激电压高时作用明显,低电压时不产生影响。结论:于绝对不应期电刺激能明显增强离体心肌的收缩功能,反应快。Objective To investigate the influences of electric signals applied during absolute refractory period（ARP）on the contractility of isolated papillary muscle from rabbits.Methods Papillary muscle was exercised from the right ventricle and was paced at 1Hz.Biphasic square wave current pulse was delivered during the absolute refractory period（called CCM）in isolated,superfused,isometrically contractility rabbit papillary muscle.The peak tension（PT）of papillary muscle,as well as maximum positive tension change（＋dT/dtmax）,were observed.Results Compared with the baseline,both PT and ＋dT/dt significantly increased during CCM stimulation by 18.2% and 21.4% respectively（P0.05）.In addition,PT increased significantly with one beat following CCM signal application and reached a new steady state level after a few beats.Once the CCM signals were turned off,the PT returned to the approximately baseline level（P0.05）.Moreover,the effect of CCM on PT was dose-response to voltage.The obvious effect was at higher voltage.No effect was observed at lower voltage.Conclusion Electric signals delivered during the absolute refractory period can rapidly enhance the contractility of myocardium,which suggests that CCM signal is a novel potent method for contractility modulation

关 键 词：收缩 绝对不应期 电刺激 乳头肌 兔 

分 类 号：R-33[医药卫生]