This study is concerned with an evaluation of the antifibrillatory activity of the drug piperidolate hydrochloride (Dactil;* N-ethyl-3-piperidyl diphenylacetate hydrochloride; JB-305), in hypothermic dogs. Seager, Kelley, and Bates1 have previously reported on the potent antifibrillatory properties of this drug in both normothermic and hypothermic animals. They observed that the drug prevented ventricular fibrillation in 20 of 24 dogs subjected to the chloroform-epinephine method of producing this arrhythmia. Further, the drug provided complete protection to 10 dogs cooled to 24-27 C on which inflow occlusion and intracardiac manipulation were performed. However, in the latter series of experiments, they did not attempt to obtain chronic survivors.
Preliminary studies were conducted on 12 animals to standardize the dosage and mode of administration of the drug. A previously reported series,2 in which ventricular fibrillation was regularly induced in 44 hypothermic animals by stimulation of the right ventricle, either by placement of sutures