对心脏“2相折返”发生机制再认识
To Recognize the Mechanism of Phase 2 Reentry in Heart
丁绍祥 1任旭爱 1王青 1王智杰 1张永利1
作者信息
- 1. 咸阳市第一人民医院心内科 陕西咸阳 712000
- 折叠
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.
Abstract
Phase 2 reentry (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 P2R within 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 2 and excited period at the same time,much less to reentry.The action potential amplitude in phase 3 changes greatly and exists supernormal period,which can be excited easily and may be the reason for reentry.
关键词
2相折返/心脏异质性/心律失常/动作电位时程Key words
phase 2 reentry/heterogeneity of the heart/arrhythmia/action potential duration引用本文复制引用
出版年
2016
NETL
NSTL
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