山羊心房不同部位有效不应期与心房颤动诱发的关系

目的:测定心房不同部位的有效不应期(ERP),并探讨其与心房颤动(AF)发生的相互关系.方法:山羊15只,运用程序刺激(S1S2程序刺激,基础起搏周长(PCL)分别为400 ms、350 ms、300 ms、250 ms、200 ms;S2为200 ms,以5 ms的步长递减)测定正常左心耳、右心耳、左上肺静脉口、左下肺静脉口、右上肺静脉口及右下肺静脉口的ERP.程序刺激结合Burst刺激对上述心房部位进行AF诱发,记录AF的发生率.结果:左心耳、左上肺静脉口、左下肺静脉口、右上肺静脉口及右下肺静脉口的ERP差异无统计学意义(P＞0.05);上述部位的ERP较右心耳ERP短(P＜0.05),AF发生率较右心耳高(P＜0.05).结论:左心房及肺静脉固有的电生理特点可能是AF主要来源于左心房的一个重要因素.

Relationship between effective refractory periods and inducibility of atrial fibrillation in different parts of atrium of goat

Aim: To determine effective refractory periods (ERPs) of the different parts of atrium and explore the correlation between the ERPs and atrial fibrillation(AF) inducibility. Methods: The ERPs of atrium and pulmonary vein ostia were measured by a decremental technique with 5-ms steps at pacing cycle lengths of 200 ms(PCL200), 250 ms(PCL250), 300 ms(PCL300), 350 ms(PCL350), 400 ms for 8 beats. AF was induced by programmable stimulation combined with burst stimulation and was recorded on ECG. Results: There was no difference among the ERPs of muscle in left superior and left inferior pulmonary vein ostia, right superior and right inferior pulmonary vein ostia and left auricle(P>0.05). The ERPs of muscle in these sites were significantly shorter than that in right auricle, and the incidence of AF in these sites was higher than that in right auricle(P<0.05). Conclusion: There is close relation between ERP and AF inducibility. Electrophysiological characteristics of left atrium and pulmonary vein maybe one of reasons that AF mainly comes from left atrium.