犬慢性快速心房起搏心房颤动模型的建立

Establishment of A Canine Atrial Fibrillation Model With Chronic Rapid Atrial Pacing.

报道犬慢性快速心房起搏心房颤动 (简称房颤 )模型的建立方法。取杂种犬 13只 ,安置实验用埋藏式高频率心脏起搏器快速起搏 ( 3 70～ 4 0 0次 /分 )心房 8～ 10周。于起搏前及起搏 8～ 10周后行经胸超声心动图、心房程序电刺激和burst刺激。 10只犬完成实验。快速起搏前所有犬均未能用心房程序刺激诱发出持续性房颤 ( >15min) ,2只 ( 2 0 %)可用burst刺激诱发出非持续性房颤。起搏 8～ 10周后 ,3只 ( 3 0 %)犬不需诱发即出现房颤。 8只 ( 80 %)可经程序刺激诱发出持续性房颤 ,其平均持续时间为 5 3± 11min。 10只犬 ( 10 0 %)均可用burst刺激诱发出持续性房颤。超声心动图检查显示快速起搏后犬心房面积显著增大 (左房 :6.4± 1.3cm2 vs 11.1± 1.8cm2 ;右房 :4 .2± 1.1cm2 vs 7.8± 1.3cm2 ,P均 <0 .0 0 1)。结论 :犬慢性快速心房起搏房颤模型具有房颤诱发率高、持续时间长、重复性好等特点。

The aim of this study was to investigate the feasibility of a canine atrial fibrillation (AF) model with chronic rapid atrial pacing (370～400 bpm) which was performed in 13 mongrel dogs.Programmed electrical stimulation and burst-pacing technique was used to induce AF,and biatrial area was measured by using two-dementional echocardiography before rapid atrial pacing and 8～10 weeks later.The experiment was completed in 10 dogs.At baseline study,sustained AF which defined as irregular repetitive atrial responses lasting at least 15 minutes failed to be induced by programmed electrical stimulation;but non-sustained AF was induced by burst pacing in two dogs.In contrast,sustained AF was readily inducible by programmed electrical stimulation in eight dogs and by burst pacing in ten dogs after 8～10 weeks pacing.When pacemaker stopped,AF occurred spontaneously in three dogs (30%).The duration of sustained AF was 53±11 min.At the end of the pacing period,biatrial area were enlarged significantly (LA:6.4±1.3 cm 2 vs 11.1±1.8 cm 2;RA:4.2±1.1 cm 2 vs 7.8±1.3 cm 2,P<0.001,respectively).Conclusion:The model is highly reproducible,and sustained AF is readily inducible for a prolonged period.