THE EFFECTS OF PROGRESSIVE SYMPATHECTOMY ON BLOOD PRESSURE

Abstract

After removal of the lumbar sympathetic chains and severance of the right splanchnics, and again after removal of the right thoracic sympathetic chains from dogs, the blood pressure underwent an initial fall followed promptly by a rise which gradually reached a level considerably above normal before it slowly returned to approximately the previous normal range. After complete exclusion of sympathetic control of the blood vessels (by final extirpation of the left thoracic sympathetic chain and severance of the splanchnics) the blood pressure dropped lower than after the previous operations and then returned to about the normal level, without any noteworthy rise above it. Extreme changes of blood pressure, before removal of the last of the sympathetic connections, were accompanied by inverse changes of the heart rate.