对心律失常中“触发活动”的再认识  

To Recognize the "Triggered Activity" in Arrhythmia

作　　者：丁绍祥 DING Shao-xiang(Department of Cardiology,the First People＇s Hospital of Xianyang City,Xianyang 712000,China)

机构地区：[1]咸阳市第一人民医院心内科,陕西咸阳712000

出　　处：《医学与哲学（B）》2018年第6期60-63,共4页Medicine & Philosophy(B)

摘　　要：触发活动是较常见的心律失常,其产生机制目前尚未完全明确。但心肌电活动有其自身规律,平台期除极几无可能,复极末再除极于同一心动周期邻近细胞时间跨度过大,否则并非同一心动周期触发。而心脏异质性既是心脏完成其生理功能的需要,也为特定条件下心律失常的产生提供了可能,若无心律失常发生,则最终体现的是心肌动作电位时程的改变。故在心脏异质性增大时,源于2相位邻近细胞间时间差值的累积为3相位能于较短时间内产生足够电压梯度提供了可能,加之本身易于激动的超常期存在,使同处3相位相邻细胞高低电位并存为心律失常产生提供了合理解释,可能是触发活动的根本原因所在。The mechanism of triggered activity is not fully understood.However,myocardial electro activity has its own character,it is impossible for triggered activity happened in platform phase,and the time span is too long for adjacent cells depolarization in the same cardiac cycle,otherwise,not the same cardiac cycle.Though heart heterogeneity is necessary for heart to complete its physiological functions,it can also lead to arrhythmia under the special conditions and reflect myocardial action potential change ultimately without arrhythmia occurred.With time difference accumulated in phase 2 among adjacent cells,a relatively large voltage gradient is produced in short time for phase 3,which makes phase 3 own both high voltage and excitable supernormal period.Therefore,as the heterogeneity of the heart increased,the coexistence of high and low potential between the adjacent cells in phase 3 can provide a reasonable explanation for arrhythmia,and maybe it is the reason for triggered activity.

关 键 词：心律失常 触发活动 2相折返 后除极 

分 类 号：R541.7[医药卫生—心血管疾病]