房室顺传和逆传对窦房结功能低下动物模型心房电生理学特性的影响

探讨房室顺传和逆传对窦房结功能障碍时心房电生理特性的影响。选择 6 0只健康新西兰大耳白家兔 ,开胸打开心包膜 ,于上腔静脉与右心耳交界处消融 ,有 5 0只成功建立单纯窦房结功能低下动物模型 ,随机分为心房起搏 (1∶1房室顺传 )组 ,心室起搏组 (又分 1∶1房室逆传组以及非 1∶1房室逆传组 )。观察房室顺传及房室逆传 1,2 ,4h以及 7d后 ,心房有效不应期 (AERP)、心房激动时间 (A2 )和心肌波长指数 (WLI)发生的变化。结果 :心室起搏 ,若存在 1∶1房室逆传 ,AERP缩短 ,A2 延长 ,WLI减小 ;若无 1∶1房室逆传 ,则AERP逐渐延长 ,A2 无明显变化 ,WLI增大。比较 1∶1房室逆传组与非 1∶1房室逆传组发现 ,同时段两组间AERP ,A2 和WLI存在显著性差异。同时发现 ,心房起搏 ,窦房结功能低下模型的AERP延长 ,A2 缩短 ,WLI增大。结论 :房室逆传能增加单纯窦房结功能低下动物模型电不稳定性 ,房室顺传则能抑制单纯窦房结功能低下动物模型心房电紊乱。

Effects of Atrioventricular Conduction and Ventriculoatrial Conduction on the Atrial Electrophysiological Characteristics in Rabbit Sinus Node Dysfuction Model

To study the influences of atrioventricular conduction(AVC) and ventricu loatrial conduction(VAC) on the atrial electrophysiological characteristics in rabbit sin us node dysfuction model,50 out of 60 selected health rabbits were successfully copied to sinus node dysf unction models by radiofrequency catheter ablating the boundary between right-atrial and superio r vena cava under opening chest and 50 rabbits were divided into three groups: 1∶1 AVC group ,1 ∶1VAC group and non 1∶1 VACgroup randomly . The changes of atrial effective refractory period(AERP),atrial activity time(A 2) and atrial wave length index(WLI) were observed under blocking autonomic nerve in three gr oups after 1 hour,2 hours ,4 hours and 7 days of pacing. Results showed that in 1∶1 VAC group AERP decreased significantly,A 2increased and WLI decreased obviously. In non 1∶1 VAC group, AERP elongated and atrial WLI increased, there was no significant changes in A 2. There was significant difference in AERP,A 2 and WLI between 1∶1 VAC group and non 1∶1 VAC group at the same pacing time.Otherwise,1∶1 could elongated AERP, improve atrial WLI and decreased A 2.Conclusion:AVC can anti-atrial disorder and VAC can auxo-atrial disorder in sinus node dysfunction animal model.