CARDIOVASCULAR CHANGES DURING CEREBRAL ANEMIA 9 



is indeed often lowered. After about half a minute of this effect, the 

 heart seems to break away from this retardation, and the beat is, if 

 anything, accelerated and pressure immediately rises to the maximum 

 level which is maintained until its final fall. The slowing of the heart 

 rate and the depression of blood pressure gives the anemic rise its 

 typical double crest. Both Gouty (16) and Stewart (26) saw this 

 double crest disappear on section of the vagi, leaving a smooth curve, 

 which attains its maximum height somewhat more rapidly, but is not 

 otherwise greatly altered in time or intensity. 



Bilateral vagotomy has been done only incidentally to other lesions. 

 The results confirm the earlier findings. 



2. Excision of the stellate ganglia. Section of the accelerators as the 

 only lesion was undertaken in five cats, all except one dissection being 

 made in the open thorax under artificial respiration. In all cases the 

 entire stellate ganglion was removed. The mass of nervous tissue was 

 secured by a hemostat and this then cut away from all the connections 

 by which it was held, until the hemostat could be removed without 

 tearing. All the records therefore give a picture of the effects obtained 

 by excision of the entire ganglion including, of course, those additional 

 accelerator fibers recorded by Ranson, Spadolini and Wickwire (60), 

 which reach the stellate ganglion by way of the superior cervical 

 ganglion. 



Hunt (62) recorded a loss of pressure on section of the stellate ganglia. 

 Wickwire found a considerable loss (60 mm.) on their section, when this 

 was undertaken without a previous vagotomy. In two cats, 1 and 3, 

 a similar depression was noted. In cat 2, however, the fall was only 

 20 mm. In cat 7, in which pressure was already very low, no change 

 at all was noted. 



Section of the accelerators on both sides seems, like double vagotomy, 

 to have a typical effect on the contour of the curve. It also tends to 

 obliterate the double nature of the curve, which then more closely 

 approaches a single peak. Characteristically, section of the accelera- 

 tors imparts to the anemic rise a marked plateau effect. After a 

 relatively restricted latent period, pressure rises sharply to its maximum 

 level (fig. 1, occlusion 2), near which it is maintained until just prior 

 to its final fall, when it may again strike the greatest height. The 

 anemic increment of pressure for the five cats examined lay between 

 120 and 160 mm. Hg. Such a vagus effect as made itself felt, curiously 

 enough, appeared somewhat later than when the accelerators were 

 intact, and the slowing was recorded at the crest of the wave at a very 



