The Present Conception of Essential Hypertension

Abstract

It is rather remarkable that the clinical study of blood pressure, a subject on which so much stress has been placed in recent years, should have had its inception only forty-eight years ago in the work of von Basch with the first sphygmomanometer, though Vierordt's 1 attempts to measure the compressibility of the pulse were made years before and Richard Bright scented the condition in his monograph on the disease bearing his name. In 1886 Flint2 mentioned the association between chronic interstitial nephritis, the resistance to the flow of blood through the small vessels, left ventricular hypertrophy, and increased arterial tension. The first contributions to the literature in this country dealing with observations on human blood pressure were made by Richard Cabot3 in 1903 and 1904. Instruments free from error for measuring the pressure were not in use until 1901,4 and the auscultatory method was described by Korotkow 5 in 1905.Since the common use of the sphygmomanometer, physicians have been observing a certain group of patients in increasing numbers who show hypertension unaccompanied by nephritis, hyperthyroidism, aortic insufficiency or any other condition usually associated with a rise in the blood pressure. To this type the name primary or essential hypertension has been given in this country, and also primary hypertensive cardiovascular disease by Janeway,1 who recognized the nonassociation of kidney disease with this type of hyper¬ tension. It corresponds to the latent angiosclerosis of von Basch, the hyperpiesis of Allbutt, the presclerosis of Huchard, and the benign essential hypertension of Volhard and Fahr.0 Essential hypertension is a pro¬ gressive disease, probably beginning in the second and third decades of life and ending usually from the third decade on, by cardiac failure, cerebral accidents or renal insufficiency: Fahr7 estimates that approximately 140,000 people die annually in the United States from hyperpiesia, and that about half these deaths are due to cardiac failure consequent to the hypertension. PROBABLE ETIOLOGYThere is no known etiology of this condition, but certain factors have been determined by clinical observa¬ tion and experimental work which undoubtedly have a marked influence on the incidence of this type of hyper¬ tension. The more important of these factors will be briefly discussed:1. Sclerosis of the arterioles of the medulla, dish¬ ing,3 in 1901, drew the conclusion from experimental work that an anemia of the vasomotor center in the medulla caused a systemic hypertension, and formulated the law that "an increase of the intracranial tension occasions a rise in the blood pressure, which tends to find a level slightly above that of the pressure exerted against the medulla." Anrep and Starling9 and Starling 10 found that vascular lesions in the medulla which impaired the blood supply can produce a com¬ pensatory rise in the systemic pressure, which rather tends to support the theory that anemia of the brain due to sclerosis of the vessels supplying the vasomotor cen¬ te...