Hypertensive disease, a frequent cause of premature disability and death, is an extremely complex problem and deserves the serious consideration of workers in all fields of medicine.
At the turn of the century, with the advent of a method for measuring blood pressure in human beings, hypertensive patients were divided into two main groups, those having some primary kidney disease and those having little or no evidence of kidney disease. The latter group is the larger, and to it the term essential hypertension is commonly applied. With this particular group we have been primarily concerned during the past twelve years.
The instability of the vascular bed in many hypertensive patients as observed by Hines and Brown1 and others strongly suggested the participation of the autonomic nervous system in this disorder. Clinicians have long recognized that an outstanding characteristic of the blood pressure of many hypertensive patients is its unusual variability. As compared with the average normotensive person they are particularly sensitive to many stimuli, physical and mental. Accordingly, it is difficult to evaluate accurately the blood pressure of most of them. This variability suggested to Hines and Brown the need for a standard method of studying their blood pressure in order to detect these physiologic characteristics.
These workers described the hyperreactivity of the vascular bed to various stimuli, particularly to cold, and found that under resting basal conditions most hypertensive patients reacted to cold stimulus, such as immersion of one hand in ice water for one minute, by an excessive. . .