Mills William R, Mal Niladri, Forudi Farhad, Popovic Zoran B, Penn Marc S, Laurita Kenneth R
Heart and Vascular Research Center, MetroHealth Campus, Case Western Reserve University, 2500 MetroHealth Dr., Rammelkamp, 6th fl., Cleveland, Ohio 44109-1998, USA.
Am J Physiol Heart Circ Physiol. 2006 Mar;290(3):H1298-306. doi: 10.1152/ajpheart.00437.2005. Epub 2005 Oct 7.
Late myocardial infarction (MI) is associated with ventricular arrhythmias and sudden cardiac death. The exact mechanistic relationship between abnormal cellular electrophysiology, conduction abnormalities, and arrhythmogenesis associated with late MI is not completely understood. We report a novel, rapid dye superfusion technique to enable whole heart, high-resolution optical mapping of late MI. Optical mapping of action potentials was performed in normal rats and rats with anterior MI 7 days after left anterior descending artery ligation. Hearts from normal rats exhibited normal action potentials and impulse conduction. With the use of programmed stimulation to assess arrhythmia inducibility, 29% of hearts with late MI had inducible sustained ventricular tachycardia, compared with 0% in normal rats. A causal relationship between the site of infarction, abnormal action potential conduction (i.e., block and slow conduction), and arrhythmogenesis was observed. Optical mapping techniques can be used to measure high-resolution action potentials in a whole heart model of late MI. This experimental model reproduces many of the electrophysiological characteristics (i.e., conduction slowing, block, and ventricular tachycardia) associated with MI in patients. Importantly, the results of this study can enhance our ability to understand the interplay between cellular heterogeneity, conduction abnormalities, and arrhythmogenesis associated with MI.
晚期心肌梗死（MI）与室性心律失常及心源性猝死相关。与晚期MI相关的异常细胞电生理学、传导异常和心律失常发生之间的确切机制关系尚未完全明确。我们报告了一种新颖的快速染料灌注技术，可对晚期MI进行全心高分辨率光学标测。在正常大鼠以及左前降支动脉结扎7天后发生前壁MI的大鼠中进行动作电位的光学标测。正常大鼠的心脏表现出正常的动作电位和冲动传导。通过使用程序刺激来评估心律失常的诱发能力，晚期MI大鼠心脏中有29%可诱发出持续性室性心动过速，而正常大鼠中这一比例为0%。观察到梗死部位、异常动作电位传导（即阻滞和缓慢传导）与心律失常发生之间存在因果关系。光学标测技术可用于在晚期MI的全心模型中测量高分辨率动作电位。该实验模型再现了许多与人类MI相关的电生理特征（即传导减慢、阻滞和室性心动过速）。重要的是，本研究结果可增强我们对与MI相关的细胞异质性、传导异常和心律失常发生之间相互作用的理解能力。
