The digital blood pressure determination. III. A study of the effects of tetraethylammonium chloride on cardiovascular dynamics, making use of blood pressure responses at the digital level

The blockade effect of the tetraethylammonium ion (TEA) on the autonomic ganglia was studied carefully during the early part of this century, 1 yet it has been only in the past few years that clinical use of this important blockade action has been considered. In this short period, however, it has been used extensively both as a therapeutic and diagnostic agent in diseases relieved by removal of autonomic tone. TEA has been used to evaluate the vasospastic element of arterial insufficiency. Following its administration the rise in temperature produced in the involved extremity is observed. Failure to obtain this rise has suggested the presence of organic occlusive arterial changes. 2,3 The drug has also been used in an attempt to determine the neurogenic component of arterial hypertension as an aid in the selection of candidates for treatment by splanchnic nerve resection. 4 A very wide range of changes in blood flow and blood pressure have been recorded in response to the administration of TEA to patients with these diseases and to normal subjects. 2–6 Little direct information is available regarding the factors responsible for this marked variability. We considered it pertinent therefore to study a group of twenty normal subjects in order to determine the range of the TEA effect unaltered by pathological factors. This study included the determinations of blood pressures at the levels of both the brachial and digital arteries, pulse rate, digital temperature, and electrocardiograms. The results proved informative not only as a basis for the interpretation of responses observed in patients with various diseases, but also yielded information about factors responsible for the wide variability in results observed.