Luo Haijian, Si Junqiang, Zhang Fengjie, Yang Zhenyu, Wang Ruxing
Department of Physiology, Shihezi University School of Medicine, Shihezi, Xinjiang 832003, P.R. China ; Department of Cardiology, Wuxi People's Hospital Affiliated to Nanjing Medical University, Wuxi, Jiangsu 214023, P.R. China ; Institute of Cardiovascular Sciences, The University of Manchester, Manchester M13 9PL, UK.
Department of Physiology, Shihezi University School of Medicine, Shihezi, Xinjiang 832003, P.R. China.
Exp Ther Med. 2014 Mar;7(3):755-757. doi: 10.3892/etm.2014.1486. Epub 2014 Jan 15.
Cardiac electrophysiological heterogeneity related to the washout of acetylcholine (ACh) remains incompletely characterized. The aim of this study was to examine whether positive cardiac inotropic action is associated with electrophysiological heterogeneity between the atrium and the ventricle after ACh perfusion and washout. Epicardial monophasic action potentials (MAPs) from the right ventricle and right atrium, as well as cardiac contractility, were recorded from isolated Langendorff-perfused rabbit hearts using MAP electrodes and a force transducer. The results indicated that rebound positive inotropic actions were induced by ACh washout with adrenaline preconditioning. This effect was accompanied by an increase in MAP amplitude (MAPA) in the right ventricle but not the right atrium. These findings indicate that cholinergic muscarinic stimulation may lead to positive cardiac inotropic action followed by changes in regional electrophysiological heterogeneity between the atrial and ventricular myocardium. Therefore, we hypothesize that electrophysiological heterogeneity is an underlying cause of arrhythmogenesis as well as hemodynamic disturbance elicited by sudden termination of vagus stimulation.
与乙酰胆碱（ACh）洗脱相关的心脏电生理异质性仍未完全明确。本研究的目的是探讨在ACh灌注和洗脱后，心脏正性肌力作用是否与心房和心室之间的电生理异质性有关。使用单相动作电位（MAP）电极和力传感器，从离体Langendorff灌注兔心脏记录右心室和右心房的体表MAP以及心脏收缩力。结果表明，肾上腺素预处理后，ACh洗脱可诱导反弹性正性肌力作用。这种效应伴随着右心室而非右心房的MAP幅度（MAPA）增加。这些发现表明，胆碱能毒蕈碱刺激可能导致心脏正性肌力作用，随后心房和心室心肌之间的区域电生理异质性发生变化。因此，我们假设电生理异质性是迷走神经刺激突然终止引发心律失常以及血流动力学紊乱的潜在原因。
