摘要
目的评价异氟醚对心室心肌细胞动作电位及跨室壁复极离散度的影响，以探讨其诱发室性心律失常的电生理机制。方法健康家兔20只，随机分为对照组和异氟醚组，每组10只，麻醉后开胸暴露心脏，采用自制心室3层心肌单相动作电位（MAPs）电极，记录左心室外膜层、中层、内膜层心肌MAPs，并同步记录体表心电图。记录心电图RR间期、QT间期及左心室3层心肌单相动作电位时程（MAPD）、复极90％的时限（MAPD90）、跨室壁复极离散度（TDa）及早期后除极的发生情况。结果与对照组相比，异氟醚组心电图RR间期和QT间期延长，左心室3层心肌MAPD90均延长，以中层心肌MAPD90延长最明显，TDR增加（P〈0．05）。异氟醚组有2只家兔中层心肌动作电位发生复极交替，1只家兔中层心肌出现早期后除极。结论异氟醚可不同程度地延长兔心室3层心肌细胞动作电位的时程，增大跨室壁复极离散度。
Objective To investigate the effects of isoflurane on the electrophysiological heterogeneity of monophasic action potential and the transmural dispersion of repolarization （TDR） of left ventricle in rabbits in vivo. Methods Twenty healthy rabbits weighing 2.5-3.0 kg were randomly divided into 2 groups （ n = 10 each） ： control group and isoflurane group（ end-tidal isoflurane concentration was maintained at 1.4%-1.6% ）. The animals were anesthetized with intraperitoneal 3% pentobarbital sodium 30 mg/kg, tracheostomized and mechanically ventilated. The chest was opened through the interspace between the left 4th and 5th ribs. The epicardium was opened and the anterior and lateral wall of the heart was exposed. Using the specially designed plunge-needle electrodes monophasic action potentials （MAPs） of epicardium, mid-myocardium and endocardium of the left ventricle were recorded together with simultaneous body surface ECG signals. RR interval, QT interval, 90% of monophasic action potential duration （MAPDso）, TDR, early after depolarization （EAD） were recorded. Results RR interval and QT interval and TDR were increased , and MAPD90 of mid-myocardium was prolonged significantly in isoflurane group as compared with control group. Alternation of repolarization in mid- myocardium was observed in 2 rabbits in isoflurane group. EAD developed in mid-myocardium was observed in only one rabbit of isofturane group. Conclusion Isoflurane can prolong the MAPD90 of the 3 layers of ventricle in different degrees and increase TDR.
出处
《中华麻醉学杂志》
CAS
CSCD
北大核心
2007年第7期632-635,共4页
Chinese Journal of Anesthesiology
基金
国家自然科学基金资助项目（30500480）
关键词
异氟醚
心肌
动作电位
Isoflurane
Myocardium
Action potentials
