医学免费论文:高频左心房起搏制作兔慢性房颤模型及电生理特性研究
【摘要】 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。
【关键词】 心房刺激; 心房颤动; 动物模型; 心房电生理特性医.学.全.在.线www.lindalemus.com
Induction of Atrial Fibrillation by Left Atrial High-Frequency Pacing and Investigationof Electrophysiological Characteristics of Atrial in RabbitsLIU Li-juan, ZHENG Dong-dan, LI Shu-bing, PAN De-mao, WANG Qiang, ZHANG Wei1, GAO Xiu-ren1. Department of Cardiology; 2. Department of Emergency,Huangpu Hospital, The First Affiliated Hospitalof Sun Yat-Sen University, Guangzhou 510700, ChinaAbstract: 【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.
Key words: artrial stimulation; atrial fibrillation; animal model; artrial electrophysiological charactoristics
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