摘要
2相折返是指心脏异质性在特定条件下增大时,心室肌复极非同步化增加,相邻细胞因2相动作电位时程不一,致高电位与低电位细胞并存,进而因电压梯度显著增大诱发低电位细胞再次兴奋。但心脏异质性于微小区域内并不明显,心肌细胞间复极时间差也不可能太大,邻近细胞同时处于2相平台期和可兴奋间期的可能性较小,更没有实质性折返存在。而3相动作电位电压变化幅度大,且存在超常期,易于激动与被激动,可能是二次激动的原因所在。
Phase 2reentry（P2R）is a local arrhythmogenic phenomenon where electrotonic current propagates from a spikeand-dome action potential region to re-excite a loss-of-dome action potential region,the heterogeneity of heart has been shown to underlie P2 Rwithin the epicardium.However,heterogeneity of the heart in microcosmos is not obvious and the time difference between the myocardial cells cannot be too long,it is impossible for neighbour cells exist in phase 2and excited period at the same time,much less to reentry.The action potential amplitude in phase 3changes greatly and exists supernormal period,which can be excited easily and may be the reason for reentry.
作者
丁绍祥
任旭爱
王青
王智杰
张永利
DING Shao-xiang REN Xu-ai WANG Qing et al(Department of Cardiology, the First People＇s Hospital of Xianyang City, Xianyang 712000, China)
出处
《医学与哲学（B）》
2016年第10期54-56,共3页
Medicine & Philosophy(B)
关键词
2相折返
心脏异质性
心律失常
动作电位时程
phase 2 reentry
heterogeneity of the heart
arrhythmia
action potential duration
