低氧和复氧致心肌电生理的改变及高钾液的影响

分别用细胞内微电极和Ｌａｎｇｅｎｄｏｒｆｆ心脏灌流技术在低氧复氧豚鼠心肌条和离体大鼠心脏上观察到：缺血多由折返机制产生以室性早搏（发生率为５／８）为主的心率失常；再灌注心律失常有触发机制参与，主要形成室颤（发生率为７／８）。高钾（１３ｍＭ／Ｌ）有类似低氧条件所致的电生理改变，且通过减少复氧早期钙离子内流而抑制后除极所致触发活动，并可阻断低氧心肌的折返通路而抑制再灌注心律失常。

The electrophysiological changes of hypoxiaand reoxygenation to myocardium andthe protective effects of hyperkalemia

By using intracellular microelectrode and Langendorff perfusing techniques, observations are given on hypoxic and reoxygenated guinea pig myocardiumstrips and isolated rat hearts. Results are as follows; ischemic arrythmias are mainlyventricle premature beats (VPB, incidence is 5/8) via reentry mechanisms , while reper-fusion arrythmias (RA) are chiefly resulted from triggered activity, form ventricle fib-rillation (VF incidence is 7/8) mostly. Hyperkalemia (13 mM/L) has almost the sameeffects on electrophysiological characteristics with hypoxic condition and can depressRA. Hyperkalemiareduce calcium influx of early period of reperfusion, depress trig-gered activity from afterdepolarization ,and interrupt reentry path in ischemic myocardium.