不同兔龄心房纤颤诱发率比较研究

Comparison of the Inducibility of Atrial Fibrillation between Young Rabbit and Old Rabbit

目的对比研究幼龄与老龄兔心房纤颤(简称房颤)诱发率差别,探究房颤与老龄的关系。方法将30只新西兰大耳白兔随机分为幼龄组(兔龄3个月,15只)、老龄组(兔龄>20个月,15只)。两组均经耳缘静脉持续泵入混合药物(2g/L氯化乙酰胆碱56ml、去乙酰毛花苷2ml、异丙肾上腺素2ml),根据心室率变化调整药物剂量,当心室率控制为基础心室率1/3时,经食管电极(冠状窦10极电极)行S1S1=1000次/min的左心房Burst刺激,观察房颤诱发情况,将>30min的房颤视为诱发成功。比较两组左心房不应期、房颤诱发率、持续时间。结果幼龄组15只兔中10只诱发成功,诱发率66%,房颤持续时间(40±8)min;老龄组15只兔中14只诱发成功,诱发率93%,房颤持续时间(58±10)min,差异有统计学意义。老龄组房颤诱发前AERP(未应用药物时测定)(90±8)ms明显短于幼龄组(120±8)ms,差异有统计学意义。结论老龄组房颤诱发率高于幼龄组,老龄兔左心房有易于房颤发生与维持的电生理基础,提示老龄可能是房颤的易患因素。

Objective To compare the difference of the inducibility of atrial fbrillation（AF） between young rabbit and old rabbit,to explore the relationship between AF and age.Methods 30 rabbits were randomly divided into young group（age=3 months,n=15） and old group（age20 months,n=15）.All of them were given mixed-drug（2g/L acecoline 56ml,deslanoside 2ml,isoprenaline 2ml） by syringe pumps via ear vein.According to heart rate,we adjusted the given dose.When heart rate come up to one third of basic heart rate,the left atrium was stimulated with TEAP（atrial pacing through esophagus） for a short burst（S1S1=1000bpm）.And then observe the ECG.We regard it as a success that duration of AF outnumbers 30 minutes.To make the comparison of left atrial atrium effective refractory period（AERP）,the inducibility of AF,the duration of AF between these two groups.Results The inducibility of and duration of AF in old group are greatly superior to those in young group the inducibility 93%VS66%,P〈0.05;the duration（（58±10）minVS（40±8）min）.The AERP measured before giving mixed-drug in old group is significantly less than young group（（90±8）ms VS（120±8）ms）.Conclusion AF is more inducible in old rabbits than young rabbits because of it,s electrophysiological feature which contribte to occurring and sustaining of AF.It give us a cue that old age is one of the risk factors of AF.