尼非卡兰和胺碘酮对心房及肺静脉肌细胞动作电位影响的比较

Comparison of the effects of nifekalant and amiodarone on action potential of atrium and pulmonary vein myocytes

目的比较尼非卡兰和胺碘酮对心房及肺静脉组织动作电位的影响,探讨尼非卡兰在房性心律失常中的作用。方法取15只大耳白兔右心房、左心房和肺静脉组织制成0.5 cm×1.5cm组织条,采用标准玻璃微电极技术,记录各部位组织动作电位和有效不应期,先基础台氏液灌注15 min后,测动作电位和有效不应期为对照组,随后分别用含2.13 mg/L尼非卡兰(尼非卡兰组)和含3.75 mg/L胺碘酮(胺碘酮组)的台氏液灌流15 min后,采用同样方法引发动作电位和测定有效不应期,比较各组动作电位时程和有效不应期。结果与对照组比较,尼非卡兰组和胺碘酮组左心房、右心房、肺静脉肌袖组织动作电位时程均显著延长,胺碘酮组左心房和肺静脉有效不应期显著延长(P<0.05,P<0.01)。结论尼非卡兰的延长心房和肺静脉肌袖组织动作电位时相及不应期的电药理作用与胺碘酮相近,可能是其治疗房性心律失常的基础。

Objective To compare the effects of nifekalant and amiodarone on action potential（AP） of atrium and pulmonary vein myocytes and to explore the possible clinical efficacy of nifekalant in treating atrial tachyarrhythmias. Methods Left and right atria and pulmonary vein removed from 15 white rabbits were cut into 0.5 cm× 1.5 cm tissue preparations. AP was induced by electric stimulation with two-fold capture threshold and recorded by standard glass microelectrode technique. Effective refractory periods（ERP） of left and right atrial and pulmonary vein tissues were measured with burst and programmed stimulation. The AP and ERP of various tissues were compared between before and after irrigation with Tyrodes fluid containing nifekalant 2.13 mg/L and amiodarone 3. 75 mg/L. Results After irrigation with Tyrodes fluid containing nifekalant and amiodarone, APD90 was prolonged from （51±16） ms to （78±33） ms （P 〈0.05） and （80±35） ms （P 〈 0.05）in the left atrium, respectively, from （53± 12） ms to （71±13） ms （P 〈 0.05） and （75±11） ms （P 〈 0.05）in the right atrium, and from （59±7） ms to （98±11） ms （P 〈 0.01） and （103±13） ms （P 〈 0.01） in pulmonary vein. ERP was prolonged significantly in pulmonary vein. Conclusion The electropharmaceutical property of nifekalant is similar to amiodarone, which may underlie the clinical efficacy of the drug in treating atrial tachyarrhythmias.