Return of neural responses after autotransplantation of the heart

Abstract

Complete excision and reimplantation of the canine heart has been accomplished with survival in 25 dogs. One animal has now been followed for 30 months and six others have survived 12–24 months. Tests of innervation status have been applied during various intervals in a number of dogs from 7 days to 24 months after cardiac autotransplantation. The total extrinsic denervation which necessarily accompanies this surgical procedure appears to persist as long as 11 months. After 1 year vagal stimulation decreases the heart rate and stimulation of the stellate ganglia causes cardiac acceleration or augmentation. Injections of tyramine, norepinephrine, and veratrum viride alkaloids are followed by responses identical to those obtained in normal dogs. The catecholamine content of the myocardium returns to normal levels. We interpret the appearance of these responses as a demonstration that connection has been reestablished with the extracardiac nervous system.