低通气量犬心房颤动模型的建立

为了对心房颤动（简称房颤）进行电生理检查和治疗的研究，对２８只犬建立低通气量房颤模型。所有犬于麻醉状态下气管插管，以低于所测潮气量１０％～１５％的通气量通气３０ｍｉｎ后，经高位右房远端电极分别给予程序刺激和Ｂｕｒｓｔ刺激诱发房颤。２只犬没能诱发房颤，２６只犬被诱发，持续时间为１ｓ～３４ｍｉｎ，诱发率为９２．８６％（２６／２８）。有４只犬房颤持续在３０ｍｉｎ以上。３只犬只能被程序刺激诱发、９只犬只能被Ｂｕｒｓｔ刺激诱发，其余１４只犬两种刺激方式均可诱发。Ｂｕｒｓｔ刺激时６００ｐｐｍ最易诱发房颤，其次为７００ｐｐｍ，其余频率范围诱发率较低。程序刺激Ｓ１Ｓ２间期诱发范围８８．８２±９．２７（７０～１００）ｍｓ。窦性心律下和房颤持续时的动脉压无明显差异，但房颤时心室率却明显增快（２５９．６±２１．３ｂｐｍｖｓ１８０．７±１８．５ｂｐｍ，Ｐ＜０．０１）。结果表明：低通气量房颤模型的制作方法简便、费用低廉、诱发率高、重复性良好。

Establishment of A Canine Atrial Fibrillation Model Under Low Ventilation

To study the electrophysiological mechanisms of atrial fibrillation (AF) and its treatment,we established a canine AF model under low ventilation in 28 mongrel dogs.After routine insertion of electrophysiological catheter leads under anesthesia,a 8.0 cuffed endotracheal tube was inserted.Dogs were ventilated with a 85%～90% measured tidal volume.AF was induced by programmed electrical stimulation and burst pacing technique at high right atria (HRA) 30 min later.AF lasting for 1 s～ 34 min was produced in 26 dogs.Other 2 was not.Its rate was 92.86%(26/28).AF induced in 4 dogs lasted more than 30 min.AF was induced in 3 dogs by programmed electrical stimulation,in 9 dogs by burst pacing technique,in 14 dogs by two kinds of stimulation.It was the easiest to be induced by burst pacing at 600 ppm,easier at 700 ppm.The mean interval of extrastimulus that AF was produced by programmed electrical stimulation was 88.82±9.27(70～100) ms.Arterial pressure under sinus rhythm and AF was insignificant,but the ventricular rate during AF was significantly increased (259.6±21.3 bpm vs 180.7±18.5 bpm,P<0.01).Establishment of the canine AF model under low ventilation is easier,cheaper,high inducibility and reinduced repeatedly.