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目的:观察氟哌啶醇对胞外钾离子浓度异常状态下兔浦肯野纤维细胞动作电位的影响。方法:采用标准微电极技术,观察不同浓度氟哌啶醇对高钾台氏液及低钾台氏液灌流的离体兔浦肯野纤维标本动作电位各电生理参数0期去极化幅值(APA)、最大除极速率(Vmax)、90%动作电位时程(APD90)及有效不应期(ERP)的影响。结果:(1)不同浓度氟哌啶醇对高钾台氏液([K+]=5.4 mmol/L)灌流的心肌传导纤维的APA呈进行性缩短趋势;ERP值较正常值也有缩短,但趋势不明显,至10μmol/L时方有统计学差异;APD90变化相对复杂,0.1、0.3μmol/L两个浓度时较正常值(P<0.05),此后,表现为轻微上升趋势,但仍低于给药前;Vmax值随浓度的增加呈明显浓度依赖性缩短趋势。(2)不同浓度的氟哌啶醇对低钾([K+]=3 mmol/L)台氏液灌流的心肌传导纤维的APA呈先增大后减小的趋势,0.1、0.3、1μmol/L时的APA较给药前略有增大,从3μmol/L时开始减小;ERP的增长较明显,Vmax值呈浓度依赖性缩短,APD90随浓度增大而延长。结论:在使用氟哌啶醇时应密切监测患者血钾浓度,氟哌啶醇可能加重低血钾时APD延长的程度,增加Q-T间期过度延长诱发Tdp的风险。
Objective: To observe the effect of haloperidol on the action potential of rabbit Purkinje cells under abnormal extracellular potassium concentration. Methods: The standard microelectrode technique was used to observe the changes of the 0-period depolarization amplitude of the electrophysiological parameters of isolated rabbit Purkinje fibers from different concentrations of haloperidol in vitro. APA, Vmax, APD90 and effective refractory period (ERP). Results: (1) The APA of haloperidol with different concentrations of cardiomyocytes perfused by KH ([K +] = 5.4 mmol / L) tended to be shortened. ERP values also shortened compared with the normal values (P <0.05). The changes of APD90 were relatively complex at the concentrations of 0.1 and 0.3μmol / L (P <0.05), and then showed a slight upward trend but still lower than Before administration, Vmax value showed a significant concentration-dependent shortening trend with the increase of concentration. (2) The APA of haloperidol at different concentrations increased first and then decreased in hypoxic ([K +] = 3 mmol / L) Myocardial conduction fibers perfused with 0.25% APA slightly increased from 3μmol / L before administration, ERP increased more obviously, Vmax decreased in a concentration-dependent manner, APD90 increased with increasing concentration. CONCLUSION: Haloperidol should be closely monitored in patients with potassium concentration, haloperidol may aggravate the degree of APD prolongation in hypokalemia, increase the Q-T interval over-prolonged induced Tdp risk.