氟卡胺对豚鼠工作心脏缺血复灌诱发心率失常的影响

用离体豚鼠工作心脏模型研究了抗心律失常药物氟卡胺诱发心律失常的初步机理。结果发现，氟卡胺在１，１０μｍｏｌ·Ｌ－１范围内对缺血复灌诱发的心律失常有明显的保护作用。但１００μｍｏｌ·Ｌ－１的氟卡胺对此模型诱发的心律失常不但无对抗作用，反而能加重和诱发心律失常。当氟卡胺１００μｍｏｌ·Ｌ－１同时加入ｌμｍｏｌ·Ｌ－１维拉帕米对此模型诱发的心律失常表现出明显的对抗作用，作用强于维拉帕米和氟卡胺单独使用。提示大剂量氟卡胺由于较强的抑制了心肌细胞钠、钾电流，从而使钙通道活性过高而产生心律失常。

Effect of flecainide on arrhythmias induced by ischemia and reperfusion in guinea pig working heart

The mechanism of arrhythmias evoked by flecainide 100μmol·L-1 on the isolated guinea Pig working heart was studied.It was found that flecainide(1～10 μmol·L-1) could inhibit the onset of arrhythmias produced by ischemia and reperfusion.However, flecainide(100μmol·L-1)could induce and aggravate the arrhythmias in this model. When flecainide of 100μmol· L-1 and verapamil of1μmol·L-1 were given together to the ischemic isolated guinea pig working hearts,the arrhythmias significantly weakened, It is suggested that the arrhythmias aggrevated by flecainide of 100μmol·L-1 in the ischemic hearts of guinea pigs may be related to the K+ and Na+ currents,which were significantly inhibited by the agent. However,Ca2+current may obviously increase because flecainide dose not suppress markedly the Ca2+ current.