伊布利特对犬心脏窦房结和房室结的作用

目的观察伊布利特对犬心脏窦房结、房室结的影响。方法 18只成年健康雄性杂种犬,麻醉后气管插管,开胸并缝合电极,伊布利特按0.10 mg/kg静脉推注给药(10 min缓推,给药30 min后按照0.01 mg/min静脉滴注维持),观察给药前后心率、窦房结和房室结功能的变化。结果伊布利特对心率有明显的抑制作用,作用的高峰时间在给药后20～30 min,2 h后心率基本恢复到用药前的水平;1只犬在给药后出现长达5 s的窦性停搏;试验中,1只犬在给药后5 min出现房室结2:1下传,给药后20 min该现象自行消失。结论伊布利特可明显减慢窦性心率,对窦房结的自律性有一定的抑制作用,对房室结的功能也有一定的抑制作用。

Effects of ibutilide on canine cardiac sinoatrial node and atrioventricular node

Objective To observe the effects of ibutilide on canine cardiac sinoatrial node (SAN) and atrioventricular node (AVN).Methods A total of 18 mongrel dogs were anesthetized and intubated with a tracheal tube. The heart was exposed through a thoracotomy and then electrodes were sutured.The heart rate (HR),the function of SAN and AVN were measured before and after ibutilide infusion(the 10-minute infusion dose was 0.10 mg/kg,30 minutes later,the maintaining dose was 0.01mg/min).Results Ibutilide had significant suppressing effect on SAN.The peak response time was 20-30 minutes after infusion,and HR got back to the baseline the condition 2 hours after ibutilide withdraw.During ibutilide infusion,one dog had 5 s sinus pause and one had 2:1 atrioventricular conduction.Conclusions Ibutilide has certainly suppressing effect on SAN and AVN.