伊伐布雷定对老年心房颤动比格犬的保护作用研究

Protective effect of ivabradine in elderly Beagle dogs with atrial fibrillation

目的探讨伊伐布雷定(ivabradine,IVB)对老年心房颤动(atrial fibrillation,AF)比格犬的影响。方法用犬龄>10岁的比格犬构建老年AF犬模型,并随机分为对照组12只和实验组12只。造模8周后,实验组给予2.0 mg·kg^(-1)·d^(-1)IVB,喂服;对照组给予等量0.9%NaCl,喂服。2组犬每天给药1次,连续干预2周。经高位右心房电极行期前程序刺激和短阵快速(Burst)刺激诱发AF,记录刺激时AF诱发的情况及持续时间,并测定肺静脉和心房的有效不应期(effective refractory period,ERP),用超声测量左心耳内径、右心房内径等心脏结构参数。结果IVB干预2周后,实验组和对照组的AF诱发率分别为16.67%和100.00%,诱发AF持续时间分别为(3.64±0.89)和(10.13±0.30)min,左心房ERP分别为(139.10±3.30)和(124.73±3.15)ms,左上肺静脉ERP分别为(138.92±3.71)和(126.37±4.00)ms,右上肺静脉ERP分别为(120.06±2.40)和(126.48±1.09)ms,左心耳内径分别为(1.41±0.10)和(1.85±0.17)cm,右心房内径分别为(1.46±0.11)和(1.96±0.11)cm,实验组的上述指标与对照组比较,差异均有统计学意义(均P<0.05)。结论IVB显著影响心房和肺静脉的ERP,显著改变心脏结构,对老年AF有明显的保护作用。

Objective To investigate the effect of ivabradine(IVB)on a canine model of atrial fibrillation(AF)in the elderly.Methods Beagle dogs aged>10 years were used to construct elderly AF dog models and were randomly divided into control group and experimental group with 12 dogs per group.After 8 weeks of modelling,experimental group was given 2.0 mg·kg^(-1)·d^(-1)IVB with oral and control group was given the same amount of 0.9%NaCl with oral.Two groups were treated for 2 weeks with once a day.AF was induced by pre-stimulation and short burst fast(Burst)stimulation via the high right atrial electrodes;the AF induction and duration of stimulation were recorded;the effective refractory period(ERP)of pulmonary veins and atria were measured.Cardiac structural parameters such as left auricular internal diameter and right atrial internal diameter were measured by ultrasound.Results After 2 weeks of IVB intervention,the AF induction rates of the experimental and control groups were 16.67%and 100.00%;the duration of AF induction was(3.64±0.89)and(10.13±0.30)min ERPs of left atrium were(139.10±3.30)and(124.73±3.15)ms;ERPs of left superior pulmonary vein were(138.92±3.71)and(126.37±4.00)ms;ERPs of right superior pulmonary vein were(120.06±2.40)and(126.48±1.09)ms;left auricular internal diameters were(1.41±0.10)and(1.85±0.17)cm;right atrial internal diameters were(1.46±0.11)and(1.96±0.11)cm;the differences were statistically significant(all P<0.05).Conclusion IVB significantly affects the ERPs of atrial and pulmonary venous,significantly alters the cardiac structure,and has a significant protective effect against atrial fibrillation in the elderly.