Electrophysiological characteristics of complex fractionated electrograms and high frequency activity in atrial fibrillation
Electrophysiological characteristics of complex fractionated electrograms and high frequency activity in atrial fibrillation
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DOI：
10.1016/j.ijcard.2013.01.194
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发表时间：
2013-10-03
影响因子：
3.5
通讯作者：
Chen, Yi-Jen
中科院分区：
文献类型：
--
作者：
Chang, Shih-Lin;Chen, Yao-Chang;Chen, Yi-Jen
背景：目前尚不清楚心房底物伴复杂分步电图（CFAEs）是否与心律失常有关。本研究旨在探讨CFAE和高频区（DF）的电生理。方法与结果：采用快速心房起搏诱发心力衰竭（HF）家兔（冠脉结扎术后4周）心房颤动（AF）。实时基底映射、多电极阵列和单相动作电位记录被用来研究CFAE和DF区域。采用常规微电极和western blot方法记录离体组织中动作电位（ap）和蛋白表达。与低DF位点或非CFAE位点相比，高DF位点的CFAE静息膜去极化电位最高，早期和延迟后去极化发生率最高，90% AP持续时间的最大斜率（APD(90)）恢复曲线（RC）最陡。高DF的CFAE部位的传导速度最慢，波长最短。与其他3个区域相比，在高DF的CFAE位点发现Na+-Ca2+交换器（NCX），阿帕胺敏感的小电导Ca2+激活的K+通道2型（SK2）和肌浆网Ca2+- atp酶上调和Kir2.1下调。NCX和SK通道的抑制延长了APD(90)，使RC的最大斜率变平，并抑制了AF。结论：在HF兔模型中，具有高DF的CFAE位点与LA的其他区域具有明显不同的致心律失常特性，这可能有助于AF的发生。版权所有。
Background: It is unclear whether atrial substrate with complex fractionated electrograms (CFAEs) is related to arrhythmogenesis. This study aimed to investigate the electrophysiology in CFAE and high dominant frequency (DF) areas.Methods and results: Atrial fibrillation (AF) was induced by rapid atrial pacing in heart failure (HF) rabbits (4 weeks after coronary artery ligation). Real-time substrate mapping, multielectrode array, and monophasic action potential recordings were used to study areas of CFAE and DF. Conventional microelectrode and western blot were used to record the action potentials (APs) and protein expression in isolated tissue preparations. CFAE site with high DF had the most depolarized resting membrane potential, highest incidence of early and delayed afterdepolarizations, and steepest maxima slope of 90% of AP duration (APD(90)) restitution curve (RC) compared to CFAE site with low DF or non-CFAE sites. CFAE site with high DF exhibited the slowest conduction velocity and shortest wavelength than the other areas. Upregulation of the Na+-Ca2+ exchanger (NCX), apamin-sensitive small-conductance Ca2+-activated K+ channel type 2 (SK2) and sarcoplasmic reticulum Ca2+-ATPase, and downregulation of the Kir2.1 were found at CFAE site with high DF compared to that observed in the 3 other areas. Inhibition of the NCX and SK channels prolonged the APD(90), flattened the maximum slope of RC, and suppressed AF.Conclusions: CFAE site with high DF had an arrhythmogenic property differing significantly from the other areas of LA in an HF rabbit model, which may contribute to the genesis of AF. (C) 2013 Elsevier Ireland Ltd. All rights reserved.