增强的肾上腺素能作用对兔室性心律失常的影响  

Effects of Augmented Sympathetic Nervous Tone on Ventricular Arrhythmia in Rabbits

作　　者：刘文举[1] 杨海玉[1] 廖晓春[1] 

机构地区：[1]广东省江门市五邑中医院暨南大学第六附属医院,529000

出　　处：《岭南急诊医学杂志》2009年第5期341-343,共3页Lingnan Journal of Emergency Medicine

摘　　要：目的:探讨增强的肾上腺素能作用对兔心律失常的影响。方法:新西兰纯种大耳白兔30只随机分为三组各10只,分别腹腔注射生理盐水1 mL、去甲肾上腺素(NE)0.5 mg/kg和NE 1.0 mg/kg,一日两次,连续15天。在体同步记录各组三层心肌单相动作电位(MAP)复极90%的时限(MAPD_(90))、跨比复极离散度(TDR)及程序刺激诱发室性心律失常情况。再静脉给予异丙肾上腺素(Iso)6 μg/(kg·min),观察急慢性肾上腺素能重叠效应对程序刺激诱发心律失常的影响。结果:(1)三组之间MAPD_(90)及TDR的比较元显著性差异。(2)高剂量组与低剂量组中层心肌的MAP 2期拱顶消失。(3)程序刺激下,早期后除极(EAD)或/和延迟后除极(DAD)及室性早搏在实验组均有增加。静脉给予Iso后与对照组比较,实验组恶性心律失常发生均有增加,但仅高剂量组P<0.05。结论:增强的肾上腺素能作用可引起兔心室肌复极电活动改变,并可导致室性心律失常增加,但对三层心肌的MAPD_(90)和TDR影响不明显,其致室性心律失常机制可能与EAD/DAD增加有关。Objective:To observe the effect of augmented sympathetic nervous tone on the electrophysiology of ventricular myocardium in rabbits.Methods:30 age-matched adult rabbits were randomly divided into three groups and each group was 10,given Sodium Chloride 1 mL,norepinephrine (NE) 0.5 mg/kg or 1.0 mg/kg respectively by intraperitoneal injection twice a day for 15 days.The effect of NE on 90% monophasic action potential duration (MAPD_(90)) and transmural dispersion of repolarization(TDR) and a programmed electrical stimulation (PES) to induce ventricular arrhythmia were observed.In order to study the eclipsing effect both long-term and short-term elevations of adrenergic activation on ventricular arrhythmia,we gave isoprenaline to all rabbit by intravenous drip at the rate of 6 μg/(kg·min).Results:(1) MAPD_(90) and TDR in all groups hadn't significant deviation.(2)The 2 phase dome of MAP in the two groups had the trend of abolition.(3)Under PES,EAD or/and DAD,and the incidence of premature ventricular contraction was statistically high in low and high dose groups.(4)After using the Iso,the incidence of the sustained ventricular tachycardia and ventricular fibrillation in low dose and high dose group increased,but only in the high dose group it had statistical significance.Conclusions:Long-term high plasma NE level increased the EAD/ DAD and incidence of ventricular arrhythmia,but no significantly effect on MAPD_(90) and TDR of ventricular myocardium.

关 键 词：增强 肾上腺素能 室性心律失常 程序刺激 心肌单相动作电位 注射生理盐水 异丙肾上腺素 无显著性差异 实验组 去甲肾上腺素 高剂量 心室肌复极 恶性心律失常 早期后除极 延迟后除极 复极离散度 TDR 中层心肌 同步记录 室性早搏 

分 类 号：R965[医药卫生—药理学]