镁对心室肌细胞迟发后除极和触发激动的影响

The Effects of Magnesium on Delsyed Afterdepolarization and Triggered Activity in Ventricular Muscles

本实验用常规微电极技术观察了镁盐对由低钾（０．６ｍｍｏｌ／Ｌ）加去甲肾上腺素（１．０ｍｇ／Ｌ）诱发的豚鼠心室乳头状肌细胞迟发后除极（ＤＡＤ）和触发激动（ＴＡ）的影响。结果表明，镁在３．０～９．０ｍｍｏｌ／Ｌ范围内，其浓度愈高，对ＤＡＤ和ＴＡ的抑制作用愈强，出现抑制效应所需时间愈短。提示镁盐具有剂量依从性抑制ＤＡＤ和ＴＡ所引起的触发性心律失常。

By the means of standard microelectrode technique the effects of magnesium on delayed afterdepolarization (DAD)and triggered activity (TA) were observed in guinea-pig papillary muscles exposed to the Tyrode's solution containing 0. 6 mmol/L KCL and 1. 0 mg/L norepinephrine. The results showed that the higher concentration of magnesium (3. 0 mmol/L～9. 0 mmol/L ), the more strongly and faster it inhibited DAD and TA. Therefore magnesium could restrain the triggered arrhythmia induced by DAD in a dose-dependent manner.