盐酸关附甲素在犬迷走神经性心房颤动模型中的作用

Effect of acehytisine hydrochloride on vagotonic atrial fibrillation in mongrel dogs

目的研究盐酸关附甲素终止心房颤动(简称房颤)的疗效,并探讨其抗心律失常作用的机制。方法30只杂种犬,在刺激双侧迷走神经的基础上给予快速心房刺激诱发房颤,随机分为生理盐水对照组、盐酸关附甲素低剂量组(15mg/kg)和高剂量组(22.5mg/kg)。观察盐酸关附甲素终止房颤和预防房颤再诱发的作用,以及对心房电生理指标的影响。结果对照组仅1只房颤终止;盐酸关附甲素低剂量组共9只房颤终止,均在注射第一剂药物后(P<0.01);高剂量组共8只房颤终止,7只在第一剂药物注射后,1只在第二剂药物注射后(P<0.01);盐酸关附甲素两个剂量组均显著延长心房不应期30ms以上;两个剂量均延长窦性周长、P波时限、PR间期、PR段、QT间期、QT-c间期、JT间期;盐酸关附甲素可预防房颤再诱发,低剂量组有6只,高剂量组有5只,均明显高于对照组(P<0.01)。结论盐酸关附甲素能够终止房颤,总有效率达87.5%,显著延长心房有效不应期可能是其抗心律失常作用机制之一;盐酸关附甲素可预防房颤再次诱发,有效率达50%以上。

Objective To observe the effect and mechanism of acehytisine hydrochloride in atrial fibrillation （AF） mongrel dogs models. Methods AF was induced by brief burst of atrial pacing in the presence of bilateral vagal stimulation in 30 mongrel dogs. The animals were randomly assigned to control group, low dose acehytisine hydrochloride （ 15 mg/kg） group and high dose （ 22.5 mg/kg） group. The effect of acehytisine hydrochloride in the termination and re-induc- tion of AF was observed. The electrophysiological changes before and after drug administration were compared. Results Acehytisine hydrochloride terminated AF in 9 dogs in low dose group （ P 〈 0.01 ） after first drug administration, 7 after first dose, and 1 after second dose in high dose group ; Only 1 AF was converted to sinus rhythm in control group （ P 〈 0.01 ）. In both groups with acehytisine hydrochloride, significant prolongation of atrial effective refractory period by 30ms in all 20 dogs was noted ; Both doses of acehytisine hydrochloride had effect of increasing sinus cycle length, duration of P wave, PR interval, PR segment, QT interval, QT-c interval and J-T interval ; AF rinduction could be prevented in 60% of low dose group and 50% of high dose group, which were significantly higher than in control group （ P 〈 0.01 ）. Conclusions Acehytisine hydrochloride has termination effect in AF models. The possible mechanism is atrial effective refractory period prolongation by drug administration; Acehytisine hydrochloride can prevent AF re-induction in more than 50% of AF animal models.