Todt H, Raberger G
Department of Cardiovascular Pharmacology, Universität Wien, Vienna, Austria.
J Pharmacol Toxicol Methods. 1992 May;27(3):191-5. doi: 10.1016/1056-8719(92)90040-8.
In small animals, His bundle activity is commonly registered using intracavitary electrodes in Langendorff-perfused hearts. The present study evaluates the feasibility of epicardial registration of His bundle activity in 30 guinea pigs in vivo, anesthetized with 60 mg/kg sodium pentobarbital i.p. Following median sternotomy, a bipolar electrode, mounted on a flexible stand, was placed into the aortic-right atrial groove. His bundle activity was easily detected in all animals. Mean PA, AH, and HV intervals were 16.7 +/- 1.4 msec (range: 6.0-34.0 ms), 36.4 +/- 1.5 ms (range: 22.0-54.0 msec) and 14.4 +/- 0.4 msec (range: 9.0-20 msec), respectively. Administration of verapamil and vagal stimulation induced significant prolongations of AH intervals without affecting HV intervals; lidocaine prolonged both AH and HV intervals. Both at baseline and following drug administration there was excellent agreement between the AH and HV intervals assessed from simultaneously registered epicardial and endocardial His bundle electrograms (n = 12). The presented model provides reproducible values for atrioventricular (AV) nodal and His-to-ventricular conduction intervals in the guinea-pig in vivo and will, thus, be a valuable tool in electrophysiologic drug evaluation.
在小动物中，通常使用Langendorff灌注心脏中的腔内电极记录希氏束活动。本研究评估了在30只经腹腔注射60mg/kg戊巴比妥钠麻醉的豚鼠体内进行心外膜希氏束活动记录的可行性。经正中胸骨切开术后，将安装在柔性支架上的双极电极置于主动脉-右心房沟内。在所有动物中均能轻松检测到希氏束活动。平均PA、AH和HV间期分别为16.7±1.4毫秒（范围：6.0 - 34.0毫秒）、36.4±1.5毫秒（范围：22.0 - 54.0毫秒）和14.4±0.4毫秒（范围：9.0 - 20毫秒）。维拉帕米给药和迷走神经刺激可使AH间期显著延长，而不影响HV间期；利多卡因则使AH和HV间期均延长。在基线和给药后，同时记录的心外膜和心内膜希氏束电图评估的AH和HV间期之间均具有良好的一致性（n = 12）。所提出的模型为豚鼠体内房室（AV）结和希氏束至心室的传导间期提供了可重复的值，因此将成为电生理药物评估中的一种有价值的工具。
