Some effects on the circulation of smoking cigarettes with varying nicotine content

It is generally agreed that the smoking of cigarettes produces immediate changes in the circulation in practically all persons. The effects are shown by an increase in heart rate and blood pressure as well as by constriction of the peripheral vessels.¹ In some patients the occurrence of vasospasm has been reported in coronary and retinal arteries.^2,3 Variability in the degree of response in different subjects depends to a greater degree on individual susceptibility to tobacco than on the presence of cardiovascular disease.⁴ Most investigators have ascribed to the nicotine in the smoke the chief role in producing these vascular reactions.^5,6,7 Some, however, still question its importance in this respect, and the suggestion has been made that sympathetic stimulation brought about by the irritating action of the smoke upon the respiratory tract may be responsible for the changes noted.⁸ Others have attributed the effects to deep breathing.⁹. Such varying opinions leave the issue still unsettled. Because the matter is of some practical importance, particularly for patients with cardiovascular diseases, this study was planned.