【摘要】 【目的】建立兔左心房高频起搏心房颤动(AF)动物模型,并进行电生理特性研究。【方法】16只健康新西兰兔随机分为:对照组和起搏组两组。两组均在左心房外膜缝合固定一起搏电极,起搏组以1 000 min-1的频率进行高频起搏;对照组不起搏。采用心外膜程序起搏技术测定心房肌的电生理特性。【结果】①起搏组3周后房颤诱发率87.5%,与对照组比较统计学有差异(P<0.01),其中持续性AF 3/8例;②起搏组经心外膜程序起搏,在高频刺激1 h、1周、3周后心房有效不应期(ERPA)均缩短,与对照组比较有显著统计学差异(P<0.01);③频率适应性方面,起搏组表现为频率适应不良,在3周时最明显,与对照组比有统计学意义(P<0.05);④起搏组3周后P波时限比对照组延长,但两者比较无统计学差别(P﹥0.05);⑤起搏组1 h至3周,ERPA缩短、相对不应期(RRPA)延长,与对照组比较统计学有差异(P<0.01)、早搏刺激的心房间传导时间(IACD)延长,与对照组比较统计学上无差别(P﹥0.05)。【结论】兔左心房高频起搏能有效建立慢性AF动物模型;主要电生理改变有:ERPA缩短、频率适应不良、P波时限延长。更多还原

【Abstract】 【Objective】 To establish the model of atrial fibrillation(AF) by high-frequency pacing and explore the atrial electrophysiological characters in rabbits.【Methods】 Sixteen rabbits were randomly divided into pacing group and control group.A pacing electricity pole was fixed under the adventitia of left atrium in all experiment animals.The pacing group was stimulated in a frequency of 1 000 bpm and the control group underwent without pacing stimulation.The technique of programmed stimulating was used to measure electrophysiological indexes of atrial in the groups.【Results】 ①87.5% of the animals in pacing group suffered from AF under 3 weeks high frequency pacing,which was significantly higher than that of control group(P < 0.01).Permanent AF was found in 3 out of 8 cases.②Atrial effective refractory period(ERPA) was statistically shortened in the pacing group comparing to the control group after 1 hour,1 week and 3 weeks stimulating(P < 0.01,respectively).③The pacing group showed a significantly poor performance of frequency adaptability comparing to the control group after 3 weeks stimulating(P < 0.05).④The P-wave interval was longer in pacing group than that of the control group after 3 weeks pacing,but no significantly different was found(P > 0.05).⑤ERPA was obviously shortened and RRPA was significantly prolonged in the pacing group after 1 hour to 3 weeks stimulating(P < 0.01),but there was no difference significantly in inter-atrial conduction defect(IACD) between the two groups(P﹥0.05).【Conclusions】 The animal model of chronic atrial fibrillation could be successfully established by high frequency pacing of atrial in rabbits.The apparent electrophysiological changes of this model include: the frequency inadaptability,shortening of ERPA and extension of P-wave interval.更多还原